identification plays a key role in the complete understanding of heavy ions
collisions in ALICE at the CERN/LHC. The High Momentum Particle
IDentification (HMPID) system will enhance the PID capability of ALICE beyond
the momentum range allowed by the energy loss measurements (ITS and TPC)
and by the TOF.
HMPID detector has been designed to extend the useful range for the
identification of p/K and K/p, on a
track-by-track basis, up to 3 GeV/c
and 5 GeV/c respectively.
will provide inclusive particle ratios and transverse-momentum spectra in the
region relevant for the study of phenomena connected with the pre-equilibrium
stage of the nucleus–nucleus collisions.
low yield of high-momentum particles in Pb–Pb collisions at the LHC energy
regime justifies the single-arm geometry of the HMPID covering about 5% of the
central barrel phase space.
Milestones reviews: Dec '02


Radiation From Japan Reaches Canada. RUN! PANIC! AAAAAH!
One day, I think I’m going to open up a news website or newspaper and there is going to be a front page headline that reads “LOOK OUT BEHIND YOU!”.
This is getting ridiculous.
New outlets, including CBC, ran an article today and yesterday about increasing radiation levels detected in Canada and in Iceland. The cause of this radiation is attributed to the crisis with the nuclear power plant in Japan. So just how big of an increase in radiation was there in British Columbia?
Gary Holub says increased radiation levels were expected, and are less than the increase in radiation levels Canadians would see naturally when it rains.
Holub stressed that the increase poses no health risk to Canadians.
Seriously? Less of an increase than when it rains? Yet the CBC chose to run a headline which said: “Increased Radiation Detected by B.C. Monitors“.
Scientific American reported what the U.S. Energy Department and the Environmental Protection Agency had to say about the increase in radiation.
They said the radiation amounted to one-millionth of the dose rate that a person normally receives from natural sources such as rocks, bricks and the sun.
This increased level of radiation is not even newsworthy, let alone worthy of a scaaaaaaaary headline. Everyone on this side of the pacific ocean has nothing to worry about.
Actually, unless you are one of the heroic Japanese workers trying to restore power to the nuclear plant, you have very little to worry about.
Does nobody remember that there were victims of an earthquake AND tsunami in Japan recently? Are we only paying attention to the nuclear plant now because news outlets love the fear generated by the word “radiation”?
Donations to the Japanese relief effort can be made through The Canadian Red Cross
Other places to make donations can be found here.


World Bulletin / News Desk
U.N. nuclear inspectors arrived in Iran on Tuesday to visit a uranium mine, Iranian media reported.
Wednesday's planned inspection of the Gchine mine in southern Iran will be the first by the International Atomic Energy Agency (IAEA) at this site since 2005.
Allowing the U.N. nuclear agency - which is investigating allegations that Iran has carried out atomic bomb research - to go to Gchine was among six concrete steps Iran agreed to under the Nov. 11 agreement with the IAEA.
"The inspectors have arrived in Tehran to make a visit to Gchine mine," Behrouz Kamalvandi, a spokesman for Iran's Atomic Energy Organisation, was quoted as saying by Fars News Agency.
The IAEA was not immediately available for a comment. Its director-general said last week that the Gchine visit would take place "in coming days".
The IAEA-Iran deal is separate from a Nov. 24 breakthrough accord between Iran and six world powers to curb Iran's nuclear programme in return for a limited easing of sanctions that have battered its economy. That agreement took effect on Jan. 20.
But both accords signalled a rapid improvement in Iran's troubled ties with the outside world, made possible by the election of a relative moderate, Hassan Rouhani, as president on a platform of endingTehran's international isolation.
Iran has moved quickly since Rouhani took office in August to improve relations with the West after years of confrontation under his hardline predecessor, Mahmoud Ahmadinejad.
Iran denies accusations it is seeking to develop atomic bombs.
As the first step to be implemented under the Iran-IAEA agreement, U.N. inspectors went to the Arak heavy-water production facility in December, a plant that is linked to a nearby reactor under construction that the West fears could yield plutonium for nuclear bombs once operational.
The other measures concerned provision of information about nuclear facilities Iran has said it plans to build.
The IAEA says it needs such access and data to gain a better understanding of Iran's nuclear programme and to ensure there is no diversion of atomic material for military purposes.
Iran says it is only refining uranium to fuel a planned network of nuclear power plants. But the same material can also provide the fissile core of an atomic bomb if enriched more.
Diplomats say the six first steps are relatively easy to implement and that it will be more difficult for Iran to agree to other action sought by the IAEA, including access to the Parchin military site where the U.N. agency believes nuclear weapons-relevant explosives tests took place a decade ago.
Iran and the IAEA will meet again in Tehran on Feb. 8 to discuss future measures. IAEA Director GeneralYukiya Amano told a news conference on Friday that they should include issues related to what the U.N. agency calls the "possible military dimensions" to Iran's nuclear programme.Last Mod: 28 Ocak 2014, 15:55


ANTECH B2104 Series Fork Detectors are routinely used as inspection tools for safeguards purposes. Also to conduct non-destructive measurements to determine the radiation from reactor pond fuel rod assemblies while stored underwater.
Fork Detectors are used to measure neutron and gamma radiation activity from spent fuel assemblies. They are supplied in two different configurations:
The difference between the different types of unit is the inner distance between the tines of the detector head; the PWR option has a larger detector head and the BWR has a small detector head. All other components are identical. The detectors are designed to be portable and easy to assemble to facilitate transportation between sites and quick set-up Detector efficiencies of 2-4% (typical) are attainable, depending on the detector type and geometry.
B2104 Series Fork Detectors are manufactured to meet EURATOM’s requirements. Each unit consists of a detector head with integral electronics, a set of connection pipes with associated interconnect clamps, O-ring seals, interconnect cables, a system status indicator unit, and a mechanism for attaching the detector assembly to the pond gantry side rails.
There are three output signals: two from the neutron detectors which are combined as a single output from the two fission chambers in each tine of the detector head, and one from the two ion chambers which is combined as a single output. These three output signals are fed into the counting electronics, such as a MiniGrand or MicroMesskanal.
The status indicator box – also known as a Top Junction Box – is fitted with Health status LED’s to indicate the presence of power to the detector head, and two further LED’s to show when pulses are being received from each Fission Chamber channel, to provide the user with a visual indication that the system is counting.
Each detector can be supplied tested with nuclear sources (optional) are are delivered with full documentation and test records including a leak test report, Certificate of conformance and manufacturers test records for preamplifier and ³He tubes.
The Top Junction Box (TJB) mounts onto the lifting pipe. It regulates and transmits the 12V or 5Vdc supply – dependent on the nucleonics specified – from the system nucleonics to drive the A111A pre-amplifiers. It also drives a series of LEDs facing the user.


|Entered date||Site||Region||Scram||Reactor type||Event description|
|ENS 54198||3 August 2019 23:33:00||Hope Creek||NRC Region 1||Manual Scram||At 1947 (EDT) on 8/3/19, with Hope Creek in Mode 1 at 37 percent power, the reactor was manually scrammed due to loss of condenser vacuum. All control rods fully inserted into the core. All safety systems responded as designed and expected. Reactor level was stabilized using Reactor Core Isolation Cooling (RCIC) and Reactor Feedwater Pumps. Currently reactor water level is being maintained by the feedwater system and decay heat is being removed by the main condenser using the main turbine bypass valves. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Due to the manual actuation of RCIC, this event is also being reported as an eight-hour, non-emergency notification per 10 CFR 50. 72(b )(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The plant is in its normal shutdown electrical lineup with all safe shutdown equipment available. The licensee will be notifying the state of Delaware, state of New Jersey and the Lower Alloway Creek township.|
|ENS 51430||28 September 2015 22:49:00||Hope Creek||NRC Region 1||Automatic Scram||GE-4||On September 28, 2015 at 2046 EDT, the Hope Creek reactor scrammed following a trip of both reactor recirculation pumps. All control rods fully inserted into the core. All safety systems responded as designed and expected. There was no radiological release. The unit is stable in Mode 3 with decay heat being removed via the turbine bypass valves rejecting steam to the main condenser. Normal feedwater level control is providing makeup to the reactor vessel. No personnel injuries resulted from the event. The Outage Control Center has been staffed to determine the cause of the reactor scram. The Hope Creek NRC Resident Inspector has been notified. The licensee notified Lower Alloways Creek township of the event.|
|ENS 49608||5 December 2013 05:40:00||Hope Creek||NRC Region 1||Automatic Scram||GE-4|
While operating at 76% power on 12/5/13 at 0325 EST, the main turbine tripped on moisture separator hi level. The reactor scrammed along with the main turbine trip. All safety systems responded as designed and expected. There was no radiological release. There were no injuries. During the scram, all rods inserted into the core. Plant is stable in Mode 3 in its normal S/D (shutdown) electrical line up. Decay heat is being removed via the turbine bypass valves dumping steam to the main condenser. At 0505 EST while securing from cooldown in an attempt to start a recirc pump, BPVs (Bypass Valve) opened causing reactor level swell and subsequent shrink. During this time, RPV (Reactor Pressure Vessel) level lowered to below RPV level 3 and caused a RPS (Reactor Protection System) actuation. RPV level was recovered and is now stable in normal band. The licensee has notified the NRC Resident Inspector.
This update to ENS #49608 adds reporting criterion 10CFR50.72(b)(3)(iv)(A) for the RPS actuation at 0505 EST during post-scram recovery.
The licensee notified the NRC Resident Inspector and the Lower Alloways Creek township. The licensee will be making a press release. Notified R1DO (Cook).
|ENS 49592||1 December 2013 10:02:00||Hope Creek||NRC Region 1||Automatic Scram||GE-4||While operating at 100% power on 12/01/2013, at 0613 EST, the main turbine tripped on moisture separator hi level. The reactor scrammed along with the main turbine trip. All safety systems responded as designed and expected. There was no radiological release. There were no injuries. During the scram, all rods inserted into the core. The plant is stable in mode 3 in its normal shutdown electrical line up. Decay heat is being removed via the turbine bypass valves dumping steam to the main condenser. The licensee notified the NRC Resident Inspector and will be notifying Lower Alloways Creek township.|
|ENS 49108||12 June 2013 16:59:00||Hope Creek||NRC Region 1||Manual Scram||GE-4||This is a report of a manual RPS actuation and manual RCIC actuation per 10CFR50.72(b)(2)(iv)(B) and 10CFR50.72(b)(3)(iv)(A). At 1332 (EDT), on 6/12/13, the 'B' Circulating Water Pump tripped with a stuck open discharge valve resulting in a vacuum transient. Operators lowered reactor power from 100% in an effort to stabilize condenser vacuum. When vacuum reached 6.5 inches, the operators inserted a manual reactor scram at 1333 (EDT). All control rods inserted as required. No automatic ECCS or RCIC initiations occurred. No primary or secondary containment isolations occurred. The plant is stable in OP CON 3 HOT SHUTDOWN with the condensate pumps in service. The Reactor Recirculation Pumps are in service. At the time of the event, a RCIC surveillance was in progress, but did not contribute to the event. The RCIC pump was secured and subsequently placed in service for inventory control. The only safety-related equipment out of service at the time of the scram was the C Service Water Pump, which was tagged for scheduled maintenance. No personnel injuries occurred. No radiation releases occurred. The NRC Resident Inspector has been informed.|
|ENS 45074||17 May 2009 05:24:00||Hope Creek||NRC Region 1||Manual Scram||GE-4|
At 0335, Hope Creek was manually scrammed due to indications of multiple control rods drifting. All rods indicate fully inserted. Reactor level is being controlled in the normal band with Start-up level control in automatic. Reactor pressure is being controlled by bypass valves to the main condenser. Recirc pumps are in service and no ECCS system actuations were reached. The failure is a solder joint on the air supply to HCU 22-15. A manual scram was reinserted at 0445 to mitigate the air leak. The licensee reset the scram to re-pressurize the scram air header. Once the leak was located, a second manual scram signal was initiated to secure the leak. No safety relief valves lifted during the transient. The electrical grid is stable and the plant is in a normal shutdown electrical lineup. The licensee will be notifying the Lower Alloways Creek Township and has notified the NRC Resident Inspector.
The failure was on HCU 22-11 not 22-15. The licensee notified the NRC Resident Inspector. Notified the R1DO (Holody) via e-mail.
On 5/17/09, at 0335, Hope Creek automatically scrammed due to low Reactor Pressure Vessel water level approximately two seconds prior to locking the Reactor Mode Switch in Shutdown due to indications of multiple control rods drifting. All rods indicate fully inserted. Reactor level is being controlled in the normal band with Start-up level control in automatic. Reactor pressure is being controlled by bypass valves to the main condenser. Recirc. Pumps are in service and no ECCS system actuations were reached. The failure is a solder joint on the air supply to HCU 22-11. A manual scram was reinserted at 0445 to mitigate the air leak.
The licensee notified the NRC Resident Inspector. Notified the R1DO(Dentel).
|ENS 43395||29 May 2007 11:22:00||Hope Creek||NRC Region 1||Manual Scram||GE-4||On 5/28/07 with Hope Creek in Operating Condition 1 at 100% Reactor power, an electrical transient and loss of 'A' and 'B' reactor feed pumps resulted in lowering reactor water level. Operators inserted a manual reactor scram at 0835 in response to the lowering reactor water level. Reactor water level lowered to (-) 38 inches subsequent to the manual scram, resulting in initiation of High Pressure Coolant Injection (HPCl) and injection to the reactor vessel. The Reactor Core Isolation Cooling (RCIC) system also initiated but tripped. Investigation of the cause of the electrical transient, loss of the 'A' and 'B' RFP's, and trip of the RCIC system are currently in progress. Initial review of the event indicates that all other systems operated as expected. Current plant conditions as of 1100 are: Hope Creek is in mode 3 at 715 psig with heat removal to the main condenser via the Main Turbine Bypass valves. All control nods fully inserted on the scram. This report also documents a 4 hour report under 10CFR50.72(b)(2)(iv)(A) for valid ECCS initiation and injection to the reactor vessel (RAL 11.3.1). The reactor is stable with the water level currently at 17 inches and feedwater being supplied by the 'C' feed pump. No Safeties lifted during the transient. All systems functioned as required except for the trip of the RCIC. The licensee was not in any major technical specification LCO at the time of the trip. The licensee notified the NRC Resident Inspector. The licensee will also notify the States of NJ and Delaware, and Lower Alloways Creek Township.|
|ENS 43132||30 January 2007 00:49:00||Hope Creek||NRC Region 1||Automatic Scram||GE-4|
On 1/29/07 with Hope Creek reactor startup in progress, in mode 1 at 22% Reactor power, Secondary Condensate Pump Minimum Flow Control Valves began to cycle. Reactor water level reached 39" (RPV level 7) and then lowered to 30" (RPV level 4). Manual control of the Reactor Feed pumps was taken, however, RPV water level continued to lower to 15" (Reactor scram on RPV water level is 12.5") at which time the reactor mode switch was locked in shutdown. There were no ECCS injections and all ECCS systems are operable. Initial review of the event indicates that all systems operated as expected with the exception of the Secondary Condensate pump minimum flow valves and the 'A' IRM failed to insert. Current plant conditions as of 1/30/07 at 0010 are: Hope Creek is in mode 3 at 565 psig. The Main Steam Line Isolation valves are open. 'B' and 'C' Primary Condensate Pumps, 'B' and 'C' Secondary Condensate Pumps, and 'A' Rx Feed Pump are feeding the vessel. All control rods have fully inserted on the scram and Main Turbine Bypass valves are removing decay heat. The licensee will inform the LAC (Lower Alloways Creek Township) and has informed the NRC Resident Inspector.
Based on the post-trip review performed by the licensee, it was determined that the in-service Reactor Feed Pump Minimum Flow Recirculation Valve opened in response to the feed flow adjustments. Reactor vessel level reached the low-level trip set point and an automatic reactor scram occurred. During the event analysis it was determined that the operator initiated the manual scram two seconds after the automatic low level scram occurred. A post event equipment performance review concluded that the Secondary Condensate Pump Minimum Flow Recirculation Valves operated as expected. The licensee notified the NRC Resident Inspector. The R1DO (Cahill) notified.
|ENS 41753||7 June 2005 15:30:00||Hope Creek||NRC Region 1||Manual Scram||GE-4|
Hope Creek manually scrammed the reactor from 100% power at 1413 and declared an Unusual Event due to unidentified drywell leakage exceeding 10 gpm (EAL 2.1.1.b) at 1437. The drywell unidentified leak rate peaked at approximately 15 gpm and is currently 12 gpm and slowly lowering. All safety systems were operable prior to the transient and responded as expected. Drywell pressure peaked at approximately 0.5 psig and is steady using normal drywell cooling (the normal pressure band is 0.1 to 0.7 psig). Drywell and suppression pools sprays were not required to mitigate the drywell pressure transient. Reactor vessel level lowered to approximately -30 inches following the scram and was returned to the normal level band using the feedwater and condensate systems. The expected vessel level 3 (setpoint +12.5 inches) ESF actuations occurred. The plant is proceeding to cold shutdown to investigate the drywell leak. The licensee notified the NRC Resident Inspector.
As of 0330, Region I IRC in consultation with NRC/IRD (McGinty) secured from Monitoring Mode based on the plant being stable at about 55 psig (about 300 degrees F) and preparing to initiate shutdown cooling. The leak rate remains at about 8 gpm, and an initial drywell entry determined the source of the leakage to be from the A-loop of shutdown cooling testable check valve (50A ). The valve was found with the position indication failed/separated and an approximate 20 foot plume of steam/liquid coming out. Plans are to continue to cool down the plant, go onto the B-loop of shutdown cooling , and isolate valve 50A. The licensee has conservatively remained in the UE and plans to exit when leak rate is assured to remain below 10 gpm (EAL entry condition) or cold shutdown is achieved and the EAL is no longer applicable. The licensee's outage center remains manned, and an NRC inspector remains on site around the clock. DHS (Hoisington), FEMA (Sweetser), DOE (Turner) EPA (Crews), USDA (Pimmons), HHS (Williams) were notified.
The licensee has placed RHR loop B into service and reached Mode 4 (cold shutdown) at 0455. Preparations are in progress to isolate the leak by closing manual valve 183.
The licensee terminated the Unusual Event at 0515 EDT based on reaching cold shutdown with the leak rate less than 10 gpm. The licensee notified the NRC Resident Inspector. DHS (Hoisington) and FEMA (Sweetser), R1D0 (Jackson), NRR EO (Hannon), and IRD (Leach) notified.
On the morning; of 06/08/05, investigation into a previously reported increase in unidentified drywell leakage (Event #41753) identified the leak location as the F050A residual heat removal (RHR) check valve. The F050A check valve is on the return line to the 'A' recirculation loop,. The F050A check valve was isolated at approximately 0545 hours. The position indication magnatrol assembly for the F050A check valve appears to be the source of the leakage. Additional investigation is proceeding to identify the exact location of the leak as well as address the structural integrity of the valve. This updated report is being made in accordance with 10CFR50.72(b)(3)(ii). At the time of this notification Hope Creek Generating station is in OPCON 4 (Cold Shutdown) at 122 degrees reactor coolant temperature. The licensee notified the NRC Resident Inspector. R1DO (Jackson) and NRR EO (Jung) notified.
|ENS 41117||12 October 2004 19:45:00||Hope Creek||NRC Region 1||Manual Scram||GE-4||During a review of post trip activities associated with MANUAL REACTOR SCRAM DUE TO A STEAM LEAK IN THE TURBINE BUILDING (Event 41110) on 10/10/04, it was determined that Technical Specifications actions requirements were inappropriately applied. With both loops of RHR in suppression pool cooling (necessary with SRV's controlling reactor pressure), procedural guidance requires that the affected loop of RHR be declared inoperable when in a secondary mode of operation. With both loops of RHR thus inoperable, the applicable Technical Specification Action TS 22.214.171.124 Action b requires that the plant be in at least HOT SHUTDOWN within 12 hours and in COLD SHUTDOWN within the next 24 hours. In accordance with the Technical Specification, this action was entered on 10/10/04 at 1831. The required time to cold shutdown was incorrectly noted as 0631 on 10/12/04. The required time was based on the combination of the 12 hours to hot shutdown and 24 to cold shutdown (or 36 hours). Because the plant was already in hot shutdown, the action should have been to place the plant in cold shutdown within 24 hours or by 1831 on 10/11/04. As a result of this error, planning activities and cooldown to cold shutdown condition was predicated on a target time of 0631 on 10/12/04 resulting in the plant exceeding the 24 hour AOT. This constitutes a condition prohibited by Technical Specifications. The plant achieved cold shutdown on 10/12/04 at 0509 hours. In addition, Emergency Classification Guide (ECG) Initiating Condition 8.5 states that the inability to reach required operational condition within Technical Specification Limits and requires the declaration of an Unusual Event if the plant is not brought to the required Operational Condition within the Technical Specification required time limit. There are no safety consequences associated with this error. There were no issues associated with the transition to cold shutdown that would have constituted an emergency condition requiring initiation of the Emergency Plan. The missed LCO and subsequent classification was based on an erroneous TS Action time and, as such, exceeding the specification occurred as a result of scheduling not plant conditions. The licensee will inform the NRC resident inspector.|
|ENS 41110||11 October 2004 00:49:00||Hope Creek||NRC Region 1||Automatic Scram||GE-4||At 2153 (hrs. EDT) on October 10, 2004, the Hope Creek Generating Station experienced an automatic reactor scram signal on low reactor level +12.5 inches (Level 3) while cooling down following a manual scram. As previously reported under Event Notification 41109, the Main Steam Isolation Valves (MSIV's) were closed as the result of a steam leak in the Turbine Building. The +12.5 inch (Level 3) scram occurred from the manual closure of a Safety Relief Valve (SRV) while it was being manually operated to reduce reactor pressure. The SRV was closed when reactor level was +24 inches, resulting in a reactor level shrink. Reactor level lowered to +8 inches, and stabilized. The secondary condensate pumps immediately restored reactor level to its normal band following the scram signal. SRV's were being utilized to assist the plant cool down because the High Pressure Coolant Injection (HPCI) system had been manually taken out of service. The HPCI vacuum tank vacuum pump tripped on an overload/power failure condition, and use was not desired. The Reactor Core Isolation Cooling (RCIC) system was out of service because of a high reactor level condition, due to plant cool down. Also, the Reactor Water Cleanup (RWCU) system was out of service due to the initial manual scram that occurred at 1814 hours which prevented normal reactor level blow down. The NRC Resident Inspector was notified and Lower Alloway Creek Township will be notified. HOO note: See Event # 41109|
|ENS 41109||10 October 2004 21:48:00||Hope Creek||NRC Region 1||Manual Scram||GE-4|
At 1814 (hrs. EDT) on October 10, 2004, Hope Creek Generating Station was manually scrammed due to a steam leak in the Turbine Building. All Control Rods inserted fully. Subsequent to the manual actuation of the Reactor Protection System, reactor pressure was reduced to minimize the effects of the steam leak. Degrading Main Condenser Vacuum following the scram resulted in trips of all operating Reactor Feed Pump Turbines at 10 (inches) HgA. The High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) Systems were manually initiated for reactor level control and the Main Steam Isolation Valves (MSIV's) were closed to isolate the leak - MSIV closure was completed prior to reaching the Main Condenser Vacuum isolation setpoint of 21.5 (inches) HgA. During plant stabilization, Reactor Water Level lowered below the RPS actuation setpoint of 12.5 inches four separate times. First, following the initial scram. Second, immediately following initiation of the HPCI and RCIC systems, when the 'A' and 'B' Reactor Water Level channels lowered to -38 inches (Level 2). Level 2 is the HPCI and RCIC actuation setpoint and Primary Containment Isolation actuation setpoint for Groups 2, 7, 8, 9, 12, 13, 14, 17, 18, 19, and 20 valves. Because only two of the four Level 2 instrument channels actuated, the isolation of these systems was channel dependent and occurred as required by the respective isolation logic. Third, following manual closure of the MSIVs. Finally, Reactor Water Level lowered below 12.5 inches following reset of the original manual scram signal which resulted in an automatic scram signal. RCIC was re-initiated manually to restore Reactor Water Level. No personnel were injured during this event. The plant is currently stable in OPCON 3 with reactor pressure at 615 psig. Pressure control (decay heat removal) was transitioned to HPCI in pressure control mode during plant stabilization. Reactor Water Level is being maintained with the Secondary Condensate Pumps. Two loops of RHR in Suppression Pool Cooling mode are in service with Suppression Pool Temperature at 110 degrees F in compliance with Technical Specification 126.96.36.199 Action b.2. Actions to determine the cause of the steam leak and effect repairs are in progress. The licensee will inform Lower Alloway Creek Township and has informed the NRC resident inspector.
On steam leak investigation, a walk down of the turbine building condenser bay determined the source of the leak to be a failure of an 8 inch moisture separator dump line. The line break is located approximately one foot from the condenser shell penetration. An additional investigation into the root cause of the failure has commenced. The NRC Resident Inspector was notified and Lower Alloway Creek Township will be notified. The Reg 1 RDO (Richard Barkley) and EO (Chris Grimes) were informed. HOO Note: See Event # 41110
|ENS 40437||12 January 2004 12:30:00||Hope Creek||NRC Region 1||Manual Scram||GE-4||On 01/12/04 at 1048 hours, the Hope Creek Generating Station reactor was manually scrammed following an invalid containment isolation signal on Reactor Building High-High Radiation. The invalid signal was caused by the combination of a scheduled sensor calibration on channel 'C', coincident with an emergent failure on channel 'A.' This combination of trip signals made up the two out of three trip logic for the Reactor Building High-High Radiation containment isolation signal. While recovering from the spurious isolation signal, the operating crew observed two of the inboard MSIV's drifting closed from a loss of pneumatic pressure as a result of the isolation signal. In response to this condition, the operating crew manually scrammed the reactor. A low reactor water level scram signal was received at 12.5 inches as expected, and reactor level was subsequently returned to the normal band using the reactor feedpumps. At the time of this event, the 'A' Control Room Ventilation Train was inoperable but available pending emergent corrective maintenance. The 'C' channel Reactor Building Radiation monitor has been returned to service and is operable, and the 'A' channel remains failed in the tripped condition. All other systems functioned as expected, and a post-transient review team is being assembled to investigate the event. Decay heat is being removed via steam to the main condenser using the bypass valves. The condensate and feedwater system is in operation maintaining reactor vessel water level. No SRVs lifted during the transient and the electrical system is stable in a normal lineup. The licensee notified the NRC Resident Inspector and will be notifying the LAC Township.|
|ENS 40378||6 December 2003 04:44:00||Hope Creek||NRC Region 1||Manual Scram||GE-4|
The reactor was being shutdown as part of a planned evolution to allow repairs on the Reactor Water Cleanup flange leak. After the Reactor Protection System Mode Select Switch had been placed in shutdown, the resulting reactor level transient caused the Level 3 low reactor level set point to be reached. The Reactor Protection System had already been de-energized and the lowest level reached during the transient was +2 inches. This level transient is a normal occurrence on a reactor shutdown, and level was restored to the normal operating band. There was no effect on the plant due to reaching the low level set point. No other abnormal plant response was noted. The licensee will notify the NRC Resident Inspector
Upon further review of this event, the resulting Level 3 low reactor water level signal following the manual scram is considered part of the pre-planned sequence in accordance with the guidance of NUREG-1022. Therefore, this event is not reportable under 10 CFR50.72(b)(3)(iv)(A) and is being retracted. Notified R1DO (J. Noggle)
|ENS 40224||4 October 2003 20:04:00||Hope Creek||NRC Region 1||Manual Scram||GE-4|
Hope Creek Generating Unit was manually scrammed at 1713 hours (EDT) on 10/04/03 due to an Electro Hydraulic Control (EHC) System oil leak. Prior to the event the unit was at 100% power. The plant responded as designed for the scram, with lowest reactor level reaching -8 inches. Reactor level is currently being maintained between +12.5 inches and +54 inches with secondary condensate pumps. The unit is currently in Mode 3 - Hot Shutdown with reactor pressure being maintained between 500-600 psig with the main turbine bypass valves utilizing the main condenser as a heat sink. The EHC leak was validated to be associated with the #4 Combined Intermediate Control Valve (CIV) and has since been isolated. This report is being generated Law Event Classification Guide section 11.3.2 - Actuation of Reactor Protection System (RPS) when critical except preplanned. Current safety system status is normal with the exception that the `B' Emergency Diesel Generator (EDG) is inoperable as the result of a relay failure and the 'B' Control Room chiller is inoperable as the result of a failed economizer float. The 'B' EDG has been retested and validation of test results are currently underway to determine operability. Common mode failure testing is in progress for the remaining three EDG's. All control rods inserted fully during the reactor scram. No relief valves lifted during the transient and there were no ECCS actuations or Primary Containment Isolation System actuations. The electrical grid remained stable during the event. NRC Resident was notified by Licensee.
During reactor level recovery following the scram, a second level 3 (+12.5 inches) RPS scram signal was received. The RPS system was still actuated upon receipt of this second level 3 signal. R1DO (Cobey ) notified of update. NRC Resident will be notified by licensee.


International Security Studies
The international community is taking gradual—yet effective—steps to secure nuclear materials, with Russia “turning the corner from nuclear problem state to nuclear solution state,” Carnegie’s Matthew Rojansky says. In this interview, he and other experts assess the 2012 Nuclear Security Summit in Seoul.
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Relationship-building techniques helped U.S. interrogators obtain the intelligence that led to the June 2006 airstrike on Al Qaeda leader Abu Zusab al Zarqawi's safehouse in Iraq. Matthew Alexander, former Air Force Criminal Investigator, discusses his experience and his book, How to Break a Terrorist.
From the Los Alamos National Laboratory to meetings in Moscow, former weapons designer Stephen M. Younger has witnessed firsthand the making of nuclear policy. He traces nuclear history from the Manhattan Project to present day in his new book, The Bomb: A New History.


On July 31st of that year, a worker from Taipower was showing his son how a Geiger counter worked when the device began detecting abnormally high radiation levels coming from the walls of his apartment. Whatever the case, at first the Atomic Energy Commission, Taiwan’s nuclear regulatory agency, was slow to act, reassuring residents that the radiation levels were actually safe. The investigation, which lasted four years and cost $15 million dollars, ended up searching some 30,000 apartments throughout Taiwan, a full 2% of which were found to be dangerously radioactive. In 2007, a team from the Taiwan Nuclear Science and Technology Association lead by W.L. Chien published a study analyzing the health outcomes of 10,000 residents of radioactive apartments, all of whom had been exposed for between 9 and 20 years.


Sean N. Liddick
(Research Description PDF)
The ease of transitions between different states of the atomic nucleus carry a wealth of information and can be used in a variety of applications from describing the basic configuration of the nucleus’ constituent protons and neutrons to constraining the synthesis of heavy elements in the energetic astrophysical events. Nuclear properties are expected to vary significantly as a function of proton or neutron number as departure is made from stable nuclei. My group focuses on characterizing transition rates of ground and excited states in nuclei as a function of proton and neutron number. Radioactive nuclei are produced and isolated at the National Superconducting Cyclotron Laboratory at Michigan State University. The nuclei of interest are deposited into a solid- state detector and their subsequent decay radiations are monitored. Decay spectroscopy provides a sensitive and selective means to populate and study low-energy excited states of daughter nuclei and a variety of different decay modes can be exploited depending on the nucleus of interest.
One branch of the groups recent experimental work has focused on . It has been predicted that multiple spin-zero states exist with significantly different intrinsic deformations in 68Ni. The energies, and decay transition rates of the excited states, can provide information on the coexisting structures. The first excited state spin-zero state of 68Ni decays through the emission of a conversion electron (photon emission is forbidden) which is delayed with respect to the populating beta-decay electron resulting in a characteristic signal shape from the solid-state detector. The energy of the conversion electron provides the energy of the excited state in 68Ni. Combined with the decay rate of the state, the strength of the transition can be determined and compared with expectations. The results confirm the theoretical picture of both single-particle and collective configurations coexisting at similar excitation energies.
The other focus of the group lies in inferring the photon strength functions (related to the photon transition rates) of highly-excited states populated in the beta-decay of a shortlived nucleus. The photon strength function combined with a knowledge of the number of nuclear states as a function of energy enables the calculation of various reactions that are expected to occur through statistical processes. One such reaction is the capture of a neutron onto the atomic nucleus increasing its mass by one unit. Neutron capture rates are a necessary ingredient to predict elemental abundances produced in energy astrophysical events, such as supernovae and neutron star mergers, which are expected to lead to the synthesis of a significant amount of the elements heavier than iron. Abundance predictions require neutron capture rate uncertainties of roughly a factor of two while current constraints can reach over two orders of magnitude. The resulting impact on abundance predictions is shown in the figure. Recent work from my group has investigated the neutron capture of 68,69Ni and the resulting impact on elemental synthesis.
Area(s) of Interest
Chemical Physics (CP)
Novel techniques for constraining neutron-capture rates relevant for r-process heavy-element nucleosynthesis, A.C. Larsen, A. Spyrou, S.N. Liddick, M. Guttormsen, Prog. Part. Nucl. Phys. 2019, 107, 69. https://doi.org/10.1016/j. ppnp.2019.04.002
Benchmarking the extraction of statistical neutron capture cross sections on short-lived nuclei for applications using the β-Oslo method, S.N. Liddick, A.C. Larsen, M. Guttormsen, A. Spyrou, B.P. Crider, F. Naqvi, J.E. Midtbo, F.L. Bello Garrote, D.L. Bleuel, L. Crespo Campo, A. Couture, A.C. Dombos, F. Giacoppo, A. Gorgen, K. Hadynska-Klek, T.W. Hagen, V.W. Ingeberg, B.V. Kheswa, R. Lewis, S. Mosby, G. Perdikakis, C.J. Prokop, S.J. Quinn, T. Renstrom, S.J. Rose, E. Sahin, S. Siem, G.M. Tveten, M. Wiedeking, F. Zeiser, Phys.Rev. C 2019, 100, 024624. https://doi. org/10.1103/PhysRevC.100.024624
Experimental neutron capture rate constraint far from stability, S. N. Liddick, A. Spyrou, B. P. Crider, F. Naqvi, A. C. Larsen, M. Guttormsen, M. Mumpower, R. Surman, G. Perdikakis, D. L. Bleuel, A. Couture, L. Crespo Campo, A. C. Dombos, R. Lewis, S. Mosby, S. Nikas, C. J. Prokop, T. Renstrom, B. Rubio, S. Siem, and S. J. Quinn, Phys. Rev. Lett. 2016 116, 242502. http://dx.doi. org/10.1103/PhysRevLett.116.242502
Shape coexistence in neutron-rich nuclei, A. Gade, S.N. Liddick, J. Phys. (London) 2016 G43, 024001. http://dx.doi. org/10.1088/0954-3899/43/2/024001
Shape coexistence from lifetime and branching-ratio measurements in 68, 70Ni, B.P. Crider, C.J. Prokop, S.N. Liddick, M. Al-Shudifat, A.D. Ayangeakaa, M.P. Carpenter, J.J. Carroll, J. Chen, C.J. Chiara, H.M. David, A.C. Dombos, S. Go, R. Grzywacz, J. Harker, R.V.F. Janssens, N. Larson, T. Lauritsen, R. Lewis, S.J. Quinn, F. Recchia, A. Spyrou, S. Suchyta, W.B. Walters, S. Zhu, Phys. Lett. B 2016, 763, 108. http://doi.org/10.1016/j. physletb.2016.10.020
B.S. Chemistry, 2001, Texas A&M Univ.
Ph.D., Chemical Physics, 2004, Michigan State Univ.
Faculty, 2009 – Present, National Superconducting Cyclotron Laboratory


Update 81- IAEA Director General Statement on Situation in Ukraine
International Atomic Energy Agency
12 Jun 2022
The International Atomic Energy Agency and the Ukrainian operator of the Zaporizhzhya Nuclear Power Plant (ZNPP) have worked together to restore the remote transmission of vital safeguards data from the facility to IAEA headquarters after a technical interruption of almost two weeks, Director General Rafael Mariano Grossi said today.
The Director General welcomed the development as an important and positive step for the implementation of IAEA safeguards at Ukraine's largest NPP. However, he also stressed that IAEA inspectors must still go to the facility as soon as possible to carry out essential nuclear material verification activities which cannot be done remotely.
The transfer of safeguards data from IAEA systems installed at the ZNPP was cut on 30 May and re-established earlier today. The images recorded by IAEA surveillance cameras during this time period are now being downloaded for review by Agency inspectors to confirm that continuity of knowledge has not been lost.
Russian forces took control of the ZNPP more than three months ago, but its Ukrainian staff are continuing to operate the plant.
"Remote transmission of safeguards data is an important element of IAEA safeguards in Ukraine and elsewhere," Director General Grossi said. "However, it is not a substitute for the physical presence of IAEA inspectors at NPPs to verify nuclear material at regular intervals."
The interval of physical inventory verifications at NPPs cannot exceed a specified duration. This is particularly critical at two of the units at ZNPP. In addition, these units have been refuelled in recent months and a physical verification of the nuclear material therein is a safeguards pre-requisite before re-starting them.
"If I am not able to dispatch inspectors to perform the required verification at ZNPP, implementation of safeguards in Ukraine will be compromised," Director General Grossi added.
The Director General said he was continuing his efforts to agree and organize an IAEA-led International Mission to the ZNPP as soon as possible to carry out safety and security work at the plant in southern Ukraine. IAEA inspectors would at the same time conduct their on-site verification activities there.
The IAEA continues to receive safeguards data from its systems installed at the other three operational NPPs in Ukraine and from the Chornobyl NPP.
Regarding the country's operational reactors, Ukraine informed the IAEA today that eight are currently connected to the grid, including two at the ZNPP, three at the Rivne NPP, two at the South Ukraine NPP, and one at the Khmelnytskyy NPP. The seven other reactors are shut down for regular maintenance or held in reserve. Safety systems remain operational at the four NPPs, and they also continue to have off-site power available, Ukraine said.
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Radium is a radioactive element in Group 2 (IIA) and Row 7 of the periodic table.
The periodic table is a chart that shows how chemical elements are related to each other.
Both polonium and radium were more radioactive than uranium.
For their work on radioactivity, the Curies were awarded the 1903 Nobel Prize in physics.
Radium was discovered in 1898 by Marie Curie (1867-1934) and her husband, Pierre Curie (1867-1934).
It was found in an ore of uranium called pitchblende.
In 1896, Becquerel made a discovery about the ore called pitchblende. Becquerel found that pitchblende gives off radiation that acts much like light.
The main difference is that the radiation from pitchblende is not visible to the human eye.
We will continue to talk about these in the following pages.Becquerel's discovery caused great excitement among scientists.


- Tariq Rauf is an expert trainer for the UNITAR’s Nuclear Disarmament and Non-Proliferation Training Programme.
- He is the former Head of Nuclear Verification and Security Policy Coordination at the International Atomic Energy Agency (IAEA) with years of experience in nuclear disarmament, non-proliferation, and arms control.
- The UNITAR nuclear disarmament training brings diplomats to Hiroshima, where they can stand at ground zero and see the bare memorial dome.
- Tariq believes the UNITAR programme fills a critical gap for developing countries in Asia, building their capacity to help build a safer world.
16 August 2023, Hiroshima, Japan - Tariq Rauf, former Head of Nuclear Verification and Security Policy Coordination at the International Atomic Energy Agency, trains diplomats from Asian countries to negotiate effectively for nuclear disarmament and non-proliferation. Since 2015, he has been a key resource person for UNITAR Hiroshima’s Nuclear Disarmament and Non-Proliferation Training Programme.
Tariq has a wealth of experience and a deep commitment to nuclear disarmament, non-proliferation and arms control. At the IAEA, he took part in developing mechanisms to ensure compliance with international nuclear safeguards and verification agreements. He also handled inspections, verification activities, and reporting on the nuclear programmes of various countries.
Missing: The human face of nuclear destruction
Tariq finds that discussions around nuclear weapons ignore the humanitarian implications of nuclear warfare.
Unfortunately, our discussions at the diplomatic and academic levels on nuclear weapons issues have become very abstract and ignore the real humanitarian and environmmental consequences and risks of nuclear weapons. We talk about these issues [as if] there were no consequences to producing and possessing nuclear weapons. –Tariq Rauf, former Head of Nuclear Verification and Security Policy Coordination at the International Atomic Energy Agency
But those implications are at the heart of why a world without nuclear weapons is essential. This is where Tariq sees the particular value of the UNITAR Hiroshima NDNP programme, which brings diplomats to Hiroshima.
In Hiroshima, not only do the diplomats learn the theoretical and practical components of nuclear disarmament; they experience standing at ground zero and seeing the bent steel rafters of the memorial dome. They meet the survivors, hibakusha, and hear first-hand about the catastrophic consequences of the detonation of a single nuclear weapon on a populated area.
Tariq believes the UNITAR programme is invaluable because it reinforces the diplomats’ commitment to nuclear disarmament and non-proliferation while letting them practice their negotiation skills to act on their commitment.
Not all countries have sufficient resources and information about nuclear issues. Tariq sees UNITAR as filling a critical gap for those countries, providing important capacity-building to help build a safer world.
It is particularly gratifying to see diplomats who have attended the UNITAR NDNP programmes play an active role in the proceedings and negotiations at nuclear Non-Proliferation Treaty and UN General Assembly First Committee (nuclear disarmament) conferences and meetings; including at the recent NPT meetings in Vienna from 24 July to 11 August 2023. – Tariq Rauf, UNITAR expert trainer
The United Nations Institute for Training and Research (UNITAR) is a dedicated training arm of the United Nations. In 2021, UNITAR trained 370,139 learners around the world to support their actions for a better future. In addition to our headquarters in Geneva, we have offices in Hiroshima, New York, Bonn and various networks around the world.
One of the eight divisions of UNITAR, the Division for Prosperity, based in the Hiroshima Office and Geneva Headquarters, seeks to shape an inclusive, sustainable and prosperous world. World-class learning and knowledge-sharing services on entrepreneurship, leadership, finance and trade, digital technologies, and nuclear disarmament and non-proliferation are offered. We empower individuals from developing countries – especially women and young people – to address inequalities. Our alumni are making a difference in least-developed countries, countries emerging from conflict, and small-island developing states.


Research Activities FY 2010-FY 2011 (NUREG-1925, Revision 1)
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Manuscript Completed: October 2010
Date Published: December 2010
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001
The Office of Nuclear Regulatory Research (RES) supports the regulatory mission of the U.S. Nuclear Regulatory Commission (NRC) by providing technical advice, tools, and information to identify and resolve safety issues, make regulatory decisions, and issue regulations and guidance. This includes conducting confirmatory experiments and analyses; developing technical bases that support the NRC's safety decisions; and preparing the agency for the future by evaluating the safety aspects of new technologies and designs for nuclear reactors, materials, waste, and security.
The NRC faces challenges as the industry matures, including potential new safety issues, the availability of new technologies, technical issues associated with the deployment of new reactor designs, and knowledge management. The NRC focuses its research primarily on near-term needs related to the oversight of operating reactors, as well as to new and advanced reactor designs. RES develops technical tools, analytical models, and experimental data to allow the agency to assess safety and regulatory issues. The RES staff develops these tools, models, and data through contracts with commercial entities, national laboratories, and universities or in collaboration with international organizations.
This NUREG presents research conducted across a wide variety of disciplines, ranging from fuel behavior under accident conditions to seismology to health physics. At times, this research also provides the technical bases for regulatory decisions and confirms licensee analyses. RES works closely with the NRC's licensing offices in the review and analysis of high-risk events and provides its expertise to support licensing. RES has organized this collection of information sheets by business lines and topical areas that summarize projects currently in progress. Each sheet provides the RES technical staff and division that can be contacted for additional information.
Page Last Reviewed/Updated Wednesday, March 24, 2021


You are here
Deputy Secretary Daniel Poneman observes instrumentation in the X-333 Process Building Control Room during his visit to the Portsmouth Gaseous Diffusion Plant. | DOE photo
Last week, I returned to my home state of Ohio to mark a milestone in the Department’s efforts to clean up our environmental legacy: the start-up of operations at the Depleted Uranium Hexafluoride Conversion Plant, or DUF6, as we commonly call it.
Depleted uranium hexafluoride has been generated in the United States since the mid-1940s as a byproduct of enriching uranium for both civilian and military applications at three gaseous diffusion plants located near Oak Ridge, Tennessee; Paducah, Kentucky; and Piketon, Ohio. Two of those plants -- at Oak Ridge and Piketon -- have now been shut down, while the third has been leased to the U.S. Enrichment Corporation, which still uses it to enrich uranium for use as fuel in commercial reactors.
The DUF6 facility will convert more than 250,000 metric tons of this depleted uranium hexafluoride into a safer form for reuse or disposal.
For decades during the Cold War, the people of Ohio stood by the Nation, and now we are standing by them and meeting our responsibility to clean up the environment.
In addition, this cutting-edge nuclear facility will provide 160 high-quality jobs for the next 18 years for Southern Ohio and keep the state at the forefront of the Nation’s nuclear enterprise, as it has been for more than half a century. In fact, Nobel Laureate Arthur Compton, who monitored Enrico Fermi’s effort to create the world’s first controlled nuclear chain reaction, came from Wooster, Ohio. On a personal level, I got my start in nuclear issues working for former Senator John Glenn, a great American who has served the Nation with great valor and distinction in times of war and peace.
Nuclear energy has a vital role to play in our low-carbon future, which is why we are working hard to reinvigorate our domestic nuclear industry – to create thousands of new jobs, promote American leadership in the nuclear field, and curb carbon pollution. The DUF6 facility will advance our scientific expertise and technological know-how in the nuclear sector.
Last Thursday was an important day for the Department of Energy, for the state of Ohio and for the Nation. Congratulations to everyone who worked so hard to make it possible.


Please use this identifier to cite or link to this item:
|Title:||Background reduction techniques and simulations for the PICASSO and PICO dark matter search experiments.|
|Keywords:||Dark matter;WIMP;superheated liquid detectors;SNOLAB;Geant4;MCNP;muon veto;muon-induced neutrons|
|Abstract:||Dark matter is one of the most challenging mysteries of cosmology. The detection of Dark Matter is a main objective in modern experimental physics. The PICASSO and then the PICO experiments work towards the direct detection of WIMPs (Weakly Interacting Massive Particles) with superheated liquid detectors. Phase transitions in the superheated liquids are triggered by the nuclear recoil caused by the elastic collision of a dark matter particle. The phase transition in the detectors leads to the formation of a gaseous bubble. The acoustic signal of the nucleation of a bubble is recorded with piezoelectric sensors and pictures of the bubbles are taken with cameras. Many techniques are used to isolate potential dark matter signal from background signals. This thesis presents the work done for the fabrication process and purification techniques of the PICASSO detectors in the clean room at Université de Montréal. The detectors built with these new purification techniques allowed a background reduction of a factor of 10. The techniques and methods will be presented as well as the latest results from the data taken with these detectors. Simulations for the PICO experiment will also be presented. MCNP neutron background simulations from radioactive materials in the PICO detector will be presented. MCNP simulations for neutrons in the SNOLAB drift will also be presented as well as other MCNP simulations for the design and optimisation of the experiment. Finally, Geant4 muon-induced neutron simulations in the SNOLAB drift will be presented as well as Geant4 simulations for the design of a muon veto. These simulations were built entirely from scratch by using the SHIELDING physics list.|
|Appears in Collections:||Material Sciences - Doctoral Theses|
Files in This Item:
|Scallon, Olivia_PhD Materials Science Final.pdf||41.88 MB||Adobe PDF||View/Open|
Items in LU|ZONE|UL are protected by copyright, with all rights reserved, unless otherwise indicated.


On 10 -11 July representatives of the National Atomic Energy Agency met at the PAA’s headquarters with the delegation of the Czech Nuclear Regulatory Authority (SUBJ). The topics of discussion regarded nuclear safety, legislation, management systems and prospects for further cooperation.
The representatives of the National Atomic Energy Agency paid a study visit to France. Mr. Janusz Włodarski, the PAA President met with Mr. Pierre- Franck Chevet, the head of the French Nuclear Regulatory Authority, ASN (Autorité de Sûreté Nucléaire). The French shared their experience regarding licensing process, conducting inspections during construction of nuclear power plant and public communication. The experts agreed on the scope and date of the PAA employees’ trainings in ASN within on-the-job-trainings.
On 29 May the leadership team of National Atomic Energy Agency met with the representatives of the UK’s Office for Nuclear Regulation (ONR). Both parties agreed that in September this year they would officially sign a Memorandum of Understanding.
On 26-28 May 2014 representatives of the National Atomic Energy Agency met in Minsk with the representatives of Belarussian nuclear regulatory authority (Gosatomnadzor). During the visit PAA delegation also visited a construction site of the Belarussian nuclear power plant in Ostrovec.


In industry, radiation is the essence of nuclear energy. Radioactive elements are divided in the reactor core, emitting neutrons (radiation - including a neutron flux), which further participate in a chain reaction. At the same time, heating occurs, and then everything is like at a thermal station.
Rosatom also plans to sterilize bark beetles and mosquitoes in order to reduce their population by irradiation.
Of course, and you probably heard about the ways of using radiation in medicine.
For example, taking X-rays (which are now gradually being replaced by X-ray tomography) would be impossible if a person had not learned how to use radiation for their own purposes.
Among other things, radiation is often used in the treatment of cancer. Radiosurgery is also considered to be relatively innovative, thanks to which it became possible to perform surgical operations without creating any incisions on the patient's body.


Stochastically Generated Multigroup Diffusion Coefficients
Pounders, Justin M.
MetadataShow full item record
The generation of multigroup neutron cross sections is usually the first step in the solution of reactor physics problems. This typically includes generating condensed cross section sets, collapsing the scattering kernel, and within the context of diffusion theory, computing diffusion coefficients that capture transport effects as accurately possible. Although the calculation of multigroup parameters has historically been done via deterministic methods, it is natural to think of using the Monte Carlo method due to its geometric flexibility and robust computational capabilities such as continuous energy transport. For this reason, a stochastic cross section generation method has been implemented in the Mont Carlo code MCNP5 (Brown et al, 2003) that is capable of computing macroscopic material cross sections (including angular expansions of the scattering kernel) for transport or diffusion applications. This methodology includes the capability of tallying arbitrary-order Legendre expansions of the scattering kernel. Furthermore, several approximations of the diffusion coefficient have been developed and implemented. The accuracy of these stochastic diffusion coefficients within the multigroup framework is investigated by examining a series of simple reactor problems.


Telescope in Lake Baikal detects signal from blazar radio burst
The Baikal-GVD telescope located in the waters of Lake Baikal in Siberia recorded an interaction event that probably comes from a very high energy neutrino. The direction of its origin is consistent with the location of the blazar PKS 0735+17, which means that its possible source is known, the Institute of Nuclear Physics PAS reports.
The neutrino event was recorded on December 8, 2021. It appeared only 4 hours after another neutrino signal was observed by the IceCube experiment in Antarctica; both signals probably originated from the same source. The information was published on the Astronomer's Telegram (https://www.asononomerstelegram.org/?read=15112).
Blazar (a distant, active galaxy, emitting a strong radiation stream towards Earth) PKS 0735+17 is one of the brightest objects of this type in the sky and a serious candidate for the source of very high energy neutrinos. In addition, it currently emits a powerful gamma, X-ray and radio burst. This powerful burst (very high energy, 43 Tev) along with the observation of two probable neutrino signals from one source constitute an extremely unique event, we read in the Institute of Nuclear Physics PAS release.
Experts from the Institute of Nuclear Physics PAS explain that neutrinos are elementary particles that interact very weakly, and thus - very rarely. Thanks to this, they carry undisturbed information about the source of their origin that can be extremely far away. On the other hand, neutrinos are very difficult to detect, which is why very large detectors are needed, with active volume reaching one cubic kilometre. Baikal-GVD is one of these detectors, it currently covers has a volume of about 0.5 km3. It is located in the clean waters of Lake Baikal in Siberia; its expansion continues to ultimately achieve the active volume of 1 km3. Its task is to register signals from secondary particles forming in the aforementioned, rare neutrino interactions. These signals are flashes of light, namely Cherenkov radiation.
The construction of the Baikal-GVD telescope is an international effort with the leading role of the Institute for Nuclear Research in Moscow and the Joint Institute for Nuclear Research in Dubna. Physicists from the Institute of Nuclear Physics PAS under the supervision of Dr. Paweł Malecki also participate in the project. A total of approx. 70 scientists and engineers from 11 research centres in Russia, Germany, Poland, the Czech Republic, Slovakia and Kazakhstan are involved. The first stage of Baikal-GVD construction was recently completed.
Baikal-GVD is not the only detector of this type. The IceCube detector in the Antarctic ice has been operating since 2010. However, it primarily observes the northern sky, while Baikal-GVD 'watches' the south (that is, for example, the centred of the Milky Way). Another telescope under construction in the northern hemisphere, KM3Net, has a much smaller active volume for now.
PAP - Science in Poland


The structure of the atom was investigated in the early 1900s by directing alpha particles at thin metal foil and measuring the angles through which the particles were deflected.
Explain why these experiments were carried out in a vacuum.
In one series of experiments, about 1 in 8000 alpha particles directed at thin gold foil
were deflected through angles greater than 90°.
Explain how this provided evidence for atoms having a concentration of charge in a
The angle at which the greatest number of alpha particles was detected for gold was 2.1°.
The experiment was repeated for other metal foils. The results are shown in the table.
Explain the pattern of results in the table.
These experiments provided evidence for a nuclear atom. Bohr suggested that
electrons can only orbit the nucleus at specific distances from the nucleus.
De Broglie developed this idea by stating that the lowest possible orbit is where thecircumference of the orbit is equal to the de Broglie wavelength for the electron.Show, by considering the force keeping the electron in orbit around a hydrogen nucleus, that this statement is true.


Lasrick (2629253) writes "In an unprecedented move, the International Atomic Energy Agency (IAEA) today retroactively re-categorized 47 Japanese nuclear reactors from "in operation" to "long-term shutdown" in its Power Reactor Information System. Thus, the global number of nuclear reactors listed as "in operation" drops from 437 to 390, a number not seen since Chernobyl-year 1986." Link to Original Source
In seeking the unattainable, simplicity only gets in the way.
-- Epigrams in Programming, ACM SIGPLAN Sept. 1982


WASHINGTON — Another chapter is out in the continuing and very public story of conflict within the Nuclear Regulatory Commission, which has now taken the form of a battle of snail mail.
The Nuclear Regulatory Commission will discuss the proposed restart of the San Onofre Nuclear Generating Station on December 18, but will not be doing so locally.
A backup, emergency generator at the San Onofre nuclear plant might have been tampered with, plant operator Southern California Edison reported to the Nuclear Regulatory Commission this week.
The US Nuclear Regulatory Commission (NRC) says DBI Inc has agreed to pay a $3500 fine after an inspection found alleged violations at a facility in Casper.
In their report, the Nuclear Regulatory Commission (NRC) found that Southern California Edison had not mislead regulators about issues at their troubled San Onofre power plant, located between San Diego and Los Angeles, California.
Margie Martinez, left, and other members of the San Diego Labor Union cheer during a public meeting held by the US Nuclear Regulatory Commission to discuss the San Onofre nuclear plant.
The Nuclear Regulatory Commission holds a public meeting at the Beach Haven Event Center in South Haven this evening to go over ongoing safety concerns at the Palisades plant.
The Nuclear Regulatory Commission has agreed to hear the Prairie Island Indian Community's concerns about extending the license for a nearby nuclear waste storage facility.
The Nuclear Regulatory Commission announced today it has scheduled an Oct 9 public meeting in Dana Point to discuss issues with the troubled San Onofre Nuclear Generating Station.
Nuclear Regulatory Commission gives tablet PCs a test run.
Joey Ledford, a spokesman for the Nuclear Regulatory Commission in Atlanta, said his agency had signed off on the repairs at the site, which is about 25 miles northwest of the capital city.
Power struggle racks Nuclear Regulatory Commission.
Nuclear Regulatory Commission conducts special inspection of the Palisades plant in southwestern Mich. Nuclear power plant in Michigan to be inspection after safety rating downgraded.
The Oyster Creek nuclear power plant remains on "alert" status even as the rising waters that caused problems with the reactor's pumping system continue to abate, a spokesman for the US Nuclear Regulatory Commission said Tuesday.
The Nuclear Regulatory Commission approved the AP1000 reactor on Thursday.


RUSSIAN authorities have confirmed reports of a spike in radioactivity in the air over the Ural mountains.
The Russian Meteorological Service said it recorded the release of ruthenium-106 in the southern Urals in late September and classified it as “extremely high contamination”. France’s nuclear safety agency earlier this month said that it recorded radioactivity in the area between the Volga river and the Ural mountains from a suspected accident involving nuclear fuel or the production of radioactive material.
At the time, Russia’s state-controlled Rosatom corporation said there had been no radiation leak from its facilities. The Russian meteorological office’s report, however, noted high levels of radiation in the villages adjacent to Rosatom’s Mayak plant for spent nuclear fuel.
Mayak has denied being the source. Greenpeace said it would petition the Russian prosecutor general’s office to investigate “a possible concealment of a radiation accident”.
This article appeared in print under the headline “Radiation cloud”


Title: Repairs at Four Nuclear Reactors Are So Expensive That They Should Not Be Restarted
Source: Fairewinds Energy Education
Date: January 13, 2013
From 13:15 – 20:15
Arnie examines a new proposal by the Department of Energy to melt radioactive scrap metal and reuse it in consumer goods like knives and forks.
- 14:15 Radioactive material from inside a nuclear plant
- 14:20 Turn radioactive vessels from liability to asset
- 15:30 Pots, pans, forks, knives, spoons
- 16:30 Highly radioactive steam generators to be used?
- 17:15 Reused material can remain in radioactive lumps
- 19:45 It’s not helping the consumer here to get any radioactive material in their baby spoons
Published: January 15th, 2013 at 1:00 am ET


Nuclear power seems to be much-debated everywhere now. Some Counterpunch and Guardian articles talking about the shaky status of nuclear power in US, UK/France and India:
New nukes not ready for Prime Time (US)
A devastating blow to the much-hyped revival of atomic power has been delivered by an unlikely source---the Nuclear Regulatory Commission. The NRC says the "standardized" designs on which theentire premise of returning nuclear power to center stage is based have massive holes in them, and may not be ready for approval for years to come.
'It feels like a sci-fi film' - accidents tarnish nuclear dream (UK/France)
For the past two weeks, Eymard, 41, and her children, 13 and seven, have had a phobia of taps. To wash up, they go out to the yard and fill a bowl from a specially delivered plastic tank of purified water on a fork-lift tractor. They carry the water up to the bathroom to wash. Even the dog drinks bottled water, and it is left out for the birds.
"I feel as if everything's constantly dirty," Eymard said, her hands deep in soapy lather scrubbing plates.
The view from the house over the fields is dominated by the nearby cooling towers of the Tricastin site, a nuclear power plant run by EDF, the company which is poised to buy British Energy and take control of most UK nuclear stations.
Next to the plant is a nuclear treatment centre run by a subsidiary of Areva, the nuclear group which hopes to design many of the new British reactors. Last month an accident at the treatment centre during a draining operation saw liquid containing untreated uranium overflow out of a faulty tank. About 75kg of uranium seeped into the ground and into the Gaffiere and Lauzon rivers which flow into the Rhône. Eymard's house is 100 metres from one of these streams.
Eyes Wide Shut in India
India ratifies nuclear deal (and Parkinson's Law)
"A nuclear reactor is so vastly expensive and complicated that people cannot understand it, so they assume that those working on it understand it. Even those with strong opinions might withhold them for fear of being shown to be insufficiently informed. On the other hand, everyone understands a bicycle shed (or thinks they do), so building one can result in endless discussions: everyone involved wants to add his touch and show that he is there"
--Parkinson's Law of Triviality (from Parkinson's Law, 1955)


The 6th International Workshop on Assurance Cases for Software-intensive Systems (ASSURE 2018) will be held on Tuesday 18th September 2018 in Vasteras, Sweden and collocated with SAFECOMP 2018.
Recent news and events
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Adelard is pleased to announce that it will be exhibiting at the SMi Defence Safety Conference to be held at Copthorne Tara Hotel, London, UK on 1st October and 2nd October 2018. The conference aims to reduce avoidable deaths, improve protection of capability and preserve the reputation of those that operate, supply and support defence services.
The Government of Canada is hosting the IAEA Technical Meeting on Justification of Commercial Industrial Instrumentation and Control Equipment for Nuclear Power Plant Application in 19-22 June 2018, Toronto, Canada.
Adelard presents at the 3rd Annual Nuclear Industrial Control Cyber Security and Resilience Conference
Prof Robin Bloomfield spoke at the 3rd Annual Nuclear Industrial Control Cyber Security and Resilience Conference on May 23rd 2018. " 'If it’s not secure, it’s not safe' - Security in the nuclear safety case". Robin addressed questions about changes to mindset and methodology, and whether claims, arguments and evidence support or hinder security informed safety cases. Adelard is at the forefront of security-informed safety: please contact firstname.lastname@example.org if you would like more details of our work in this area or details of the talk.


You may have heard about colorful silicone wristbands and athletic tape infused with minerals that are supposed to release “negative ions.” You might even be wearing one. They are touted as improving balance and strength, enhancing flexibility and motion, and improving mental focus and alertness. They’ve been sold on the Internet or in retail stores across the U.S.
The minerals these products contain can vary from volcanic ash and titanium to less familiar ones such as tourmaline, zeolite, germanium and monazite sand. They may also contain naturally occurring radioactive elements, including uranium and thorium. In trace amounts, these materials do not warrant much attention. But the radioactive emissions—that is to say gamma rays—from several of these products were detected on entry to the country by U.S. Customs and Border Protection officials using radiation monitoring equipment.
While they may be radioactive, these products are not expected to create any health impacts. The amount of radiation given off by these products is well below the level that would cause any health concern or illness, even if worn over several years.
But NRC licensing requirements for uranium and thorium depend on the amount of radioactive material present. We commissioned the Oak Ridge National Laboratory to do an analysis that found enough radioactive thorium in several ion technology products that they require an NRC license for manufacture, distribution and possession in the U.S.
NRC staff experts on radiation worked with federal agencies and state regulators to determine the most appropriate path forward. Products containing negative ion technology — that is to say containing licensable amounts of radioactive material — should not be sold at the present time because they have not been licensed, as required, by the NRC.
Anyone wishing to dispose of a negative ion product may simply put it in their trash. This is OK because, although the amount of radioactive material requires licenses for manufacture and sale, it does not require any special handling or disposal.
We cannot say whether these products work as advertised. If you have them or know someone who does, our best advice is to throw them away. Anyone with health concerns should talk to their doctor. In the meantime, we’ll continue to do all we can to make sure they are being regulated properly.


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A team of Los Alamos scientists are helping in the recovery efforts after the devastating effects of the 2011 tsunami that heavily damaged Japan’s Fukushima reactor. They are helping assess the severity of damage within the reactor’s core.
Damage of the reactor cores has attracted worldwide attention to the issue of the fundamental safety of atomic energy. A cold shutdown was announced by the Japanese government in December 2011, and a new phase of cleanup and decommissioning was started.
However, it is difficult to plan the dismantling of the reactors without any realistic estimate of the extent of the damage to the cores, and knowledge of the location of the melted fuel.
In the case of Three Mile Island, it took more than three years before a camera could be put into the reactor, and about 10 years before the actual damage to the reactor could be assessed. Since access to the reactor buildings is very limited due to high radiation fields, imaging the reactor cores from outside the buildings will be a valuable step, and can reduce the time required to dismantle the reactors significantly, resulting in cost savings and lower total worker radiation dose.
A study in the journal AIP Advances by a team of scientists from Los Alamos National Laboratory (LANL) provided some clarity to the problem.
The LANL scientists believe that muon imaging may offer the best hope of assessing damage to the reactor cores and locating the melted fuel.
Muon imaging, which utilizes naturally occurring muons created in the atmosphere by cosmic rays to image dense objects, should solve the problem of determining the spatial distribution of the reactor fuel in the short term, the LANL team said.
“Muons are scattered more strongly by high-Z materials such as uranium fuel in Fukushima’s reactor,” explained LANL researcher Haruo Miyadera, who is the lead author of the paper. “By measuring the scattering angle, and understanding the physics of Coulomb multiple scattering, one can assess the locations and amount of the melted fuel.”
This new technique offers significant advantages over traditional muon imaging.
The traditional method is similar to Roentgen radiography in that it measures muon-flux attenuation after an object. Muons, however, are scattered in a manner that causes image blur.
“The new LANL method measures muon trajectories both before and after the object,” said Miyadera.
“By combining the incoming and outgoing trajectories, one can more accurately specify the location of the scattering, yielding a clearer image.”
Why is Imaging Fukushima So Challenging?
Assessing the core damage at Fukushima is a very difficult challenge, said Miyadera.
In the case of Three Mile Island, cameras were eventually installed in the reactor pressure vessel to assess the damage. However, in the case of Fukushima Daiichi, access inside the reactor pressure vessel has been very limited due to high radiation.
To address this, the team plans to install detectors in front of the reactor building and on the second floor of the turbine building so that their muon scattering technique can assess the damage without direct access to the reactor building.
The LANL team has faced numerous challenges, from operating detectors in the high radiation environment at Fukushima Daiichi to the difficulties in finding funding for a project at an American laboratory to address a problem in Japan.
The next step for the crew is a demonstration of their technique using a research reactor in Kawasaki, Japan where they will verify the spatial resolution of their technique and track the effects of obstructions such as concrete walls and steel construction materials on the muon scattering.
“A few months of measurement will reveal the distribution for reactor core fuel and will accelerate the planning and execution of reactor dismantlement, potentially reduce the overall project span by years, reduce overall worker radiation doses, and help Japan and the nuclear power industry in the recovery process from this catastrophic event,” Miyadera said.
The article, “Imaging Fukushima Daiichi reactors with muons” by Haruo Miyadera, Konstantin N. Borozdin, Steve J. Greene, Zarija Lukić, Koji Masuda, Edward C. Milner, Christopher L. Morris and John O. Perry is published in the journal AIP Advances. See: http://dx.doi.org/10.1063/1.4808210
More on this story in Sunday’s Los Alamos Monitor.


Radioactive material was released from the power station following the accident. However, measures including decontamination initiatives have significantly reduced radiation levels. In Difficult-to-Return Zones, decontamination work is ongoing.
According to surveys of ambient doses rates over an 80-kilometer radius around the TEPCO Fukushima Daiichi Nuclear Power Station, the average dose at a height of 1 meter from the ground has decreased by around 78% since immediately after the accident.
What's more, radiation levels will continue to decrease naturally as radioactive materials stabilize. This process occurs over time, with the material emitting less radiation as it becomes more stable.
As of March 2018, thorough area-wide decontamination work has been completed in 100 municipalities across 8 prefectures (not including Difficult-to-Return Zones). The work is being carried out in accordance to the Act on Special Measures Concerning the Handling of Environment Pollution by Radioactive Materials. It has been ongoing since January 2012 and is being carried out at local- and central-government levels.


An anonymous reader writes "Three weeks after the nuclear crisis began at Japan's Fukushima Dai-1 power plant, there's still a real danger of melted nuclear fuel escaping the reactor buildings and releasing a large dose of radiation. So says Theo Theofanous, an engineer who spent 15 years studying the risks of nuclear reactors. Theofanous believes that melted nuclear fuel has already leaked through the reactor vessels and accumulated at the bottoms of the primary containment structures. All attempts to keep the reactor buildings cool may not be enough to prevent the overheated fuel from eating through the concrete floors, he says."
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From Nov. 25 – Dec. 2, I was fortunate enough to represent Good Energy Collective among hundreds of young nuclear professionals in Koriyama, Japan. The International Youth Nuclear Congress (IYNC) is held every two years. It is designed to connect those in the nuclear field from across the world to discuss all things nuclear, and facilitate knowledge sharing and transfer across borders and generations.
Fukushima Daiichi Nuclear Power Station
IYNC 2022 was held in the Fukushima Prefecture of Japan, where nearly 12 years ago the Tōhoku earthquake and tsunami contributed to core meltdowns and hydrogen explosions at the Fukushima Daiichi Nuclear Power Station. Hundreds of thousands of residents were evacuated. IYNC explored the accident, addressing various aspects in two conference sessions and multiple technical tours of the site and related facilities. Touring the disaster site was surreal; and the impacts spread far beyond the site. As we drove into the facility, we saw numerous homes filled with furniture and stores with untouched merchandise, overgrown with foliage, abandoned to this day due to high levels of radioactivity.
TEPCO, the utility company responsible for the accident, has built a number of accompanying facilities focused on public engagement and communication. The TEPCO Decommissioning Archive Center, which provides an ongoing history of efforts to decommission the plant, is prominent. I was surprised, actually, by the direct language that TEPCO used to take responsibility for the disaster. While the impacts of their efforts are yet to be realized, I do believe that there is a lesson the nuclear industry should learn — taking responsibility for past and continuing injustices is a necessary step to regain the trust of the public. TEPCO’s facilities, videos, educational materials, and tour facilitations felt like genuine attempts to improve public relations practices.
I was further surprised to learn how community engagement practices have altered the ways in which TEPCO is implementing disaster recovery activities. This is most clearly shown in how the company releases treated seawater into the oceans outside of Fukushima. As a result of the accident, and continuing to this day, TEPCO circulates water around the cores of reactors, which becomes contaminated as a result. While this water is treated to remove several dangerously radioactive substances from the water (like Strontium-90 and Cesium-137), it is particularly difficult to remove Tritium. This radioactive element is heavily present in water at the Daiichi site, but the company plans to release the water into the ocean after diluting it.
Their process for releasing this water has been controversial, yet consultation with local stakeholders has been able to influence TEPCO’s decision-making. Public concerns from fishers, residents, and others have led to the addition of new monitoring stations. TEPCO is also diluting the water further to ease community concerns.
Yet outside of the technical details, the damage caused by this facility is vast. The experience of standing in front of the damaged reactors is hard to put into words. It’s a clear reminder that risk will always be present in nuclear power, and we must recognize it, understand it, and communicate about risk more effectively.
I’m grateful to have been given the opportunity to see the site up close. The efforts by the thousands of employees on-site at Fukushima Daiichi every day are inspirational.
International Youth Nuclear Congress (IYNC) 2022
While the Fukushima Daiichi accident was important, it wasn’t the core of IYNC. The week consisted of a number of panel sessions, workshops, discussions, and other events with diverse topics — from spent fuel to new reactor technologies.
Communication and outreach was a key theme throughout the week. Panels on communication focused on how we talk about nuclear and how we can attract younger people into work and advocacy for nuclear into the future. For instance, both Rauli Partanen from Think Atom (Finland) and Eric Meyer from Generation Atomic (USA) commented on how positive nuclear messaging can provide hope in the fight against climate change. Yet real change will require shifts in how we go about having difficult conversations. For example, Lisa Frizzell from Canada’s Nuclear Waste Management Organization highlighted that Canada’s successes in engagement have focused on listening to communities (especially First Nation communities) and engaging with people where they’re at.
I was grateful to present about the role of nuclear on a just and equitable grid, drawing from a number of the reports we’ve released this year. The desire of professionals to engage with justice work in nuclear energy was exciting. Directly after my presentation, I received many comments and questions that highlighted how much more research is still needed. There seems to be a keen interest in the social impacts of nuclear across the industry.
While there was a Russian-sized elephant in the room (until Russia’s invasion of Ukraine, the conference was going to take place in Sochi), the international collaboration was notable and friendly. Innovation was present in every room as technical track speeches covered everything from comfortable radiation protection for healthcare workers to new air filters for emergency nuclear reactor vents. Ideas were floated about the future of nuclear marine docks for nuclear-powered shipping vessels and using bitcoin mining to manage excess energy supply in new reactor constructions.
The theme of IYNC 2022 was “You are the core.” While cheesy, I found it apt — nuclear today and the future of the technology tomorrow will be driven by the efforts of passionate and brilliant folks from across the globe. There was an apparent eagerness and passion among attendees to help solve climate change with the help of nuclear energy. In a conversation with Mark Nelson from Generation Atomic, he asked me what gives me hope. My answer was people — especially the engaged and passionate people I was lucky enough to get to know at IYNC this year.
Thank you — very much — to the Good Energy Collective team for sending me to represent our organization, and thank you to the IYNC team for hosting a stellar conference.


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UCOR wins Top Workplace award
United Cleanup Oak Ridge (UCOR), the lead environmental cleanup contractor for the Department of Energy’s Oak Ridge Office of Environmental Management (OREM), has been named one of the Knoxville News Sentinel’s “Top Workplaces” in eastern Tennessee for 2022. The award is the result of a confidential, third-party survey of UCOR’s 2,000-member workforce by the Knoxville News Sentinel and the survey company Energage.


An accident at a shuttered nuclear power plant in central Japan sent smoke billowing into the air Friday, but there were no reports of radiation leaks or injuries.
It wasn't immediately clear what happened inside the experimental plant, near the town of Tsuruga. City spokesman Yoshihiro Kadono said the accident occurred at an incinerator in the nuclear complex.
Firefighters rushed to the scene after reports of an explosion, a local fire official said. There was no sign of fire from the outside, however, and the smoke subsided without firefighters turning on their hoses, he said.
The incinerator is used to burn items contaminated with low-level radiation, such as workers' protective clothing, an industry and trade ministry official said.
A spokesman at the Nuclear and Industrial Safety Agency said on condition of anonymity there was no danger of leaking radiation because the plant had not been generating power since March. It was shut down because of high operating costs.
Chikara Gunji, a spokesman at the facility's operator, Japan Nuclear Cycle Development Institute, said the incinerator had shut down automatically early Friday after it began to overheat. Plant officials tried to restart the incinerator about a half-hour later, and the fire alarm was triggered shortly thereafter.
It wasn't immediately clear what triggered the overheating, Gunji said.
Officials later found that a viewing window attached to the incinerator duct was broken, and that wind had probably stirred up ash inside the burning chamber, Gunji said. The flying ash may have triggered the fire alarm, he speculated.
Gunji said some workers inside the compound also reported hearing an explosion. About 100 people were in the complex, which is being dismantled.
The Japanese government decided in 1995 to close down the Fugen plant at the end of March due to high operating costs. It had an output of 165,000 kilowatts of electricity.
Fugen was designed to burn a mixture of uranium and plutonium as a transition to more advanced fast-breeder reactors, which use plutonium fuel instead of uranium and produce more plutonium that can be used as fuel.
Fugen began operation in 1979 in Tsuruga, 200 miles west of Tokyo. Dismantling it will take 40 years, according to its operators.
By Mari Yamaguchi


Please use this identifier to cite or link to this item:
|Title:||Safety Characteristics of a Suspended-Pellet Fission Reactor System|
|Authors:||Kingdon, Ross David|
|Keywords:||Engineering Physics;Engineering Physics|
|Abstract:||
A new fission reactor system with passive safety characteristics to eliminate the occurrence of loss-of-coolant accidents, reduce reactivity excursion effects, and which also provides for closure of the nuclear fuel cycle through on-site spent fuel management is examined. The concept uses multi-coated fuel pellets which are suspended by an upward moving coolant in vertical columns of the reactor core and electro-refining elemental separation to remove selected fission products prior to actinide recycling. The possibility of fuel melt following a loss-of-coolant is avoided as a decrease in coolant flow results in the removal of fuel from the core through the action of gravity alone. Average fluid velocities in the columns which are necessary to suspend the pellets are calculated and found to be consistent with the necessary heat extraction to yield ~1-10MWth per column. The total output power of such suspended pellet-type reactors is compared to the power necessary to provide the suspending fluid flow, yielding favourable ratios of ~10² - 10³ The reduction of reactivity excursion tendencies is envisaged through an ablative layer of material in the pellets which sublimates at temperatures above normal operating conditions. In the event of a power or temperature increase the particles fragment and thereby change their hydrodynamic drag characteristics, thus leading to fuel removal from the core by elutriation. Comparison of nuclear-to-thermal response times and elutriation rates for limiting power transients indicate that the present design assets in reactivity excursion mitigation. Closure of the nuclear fuel cycle is attained through a spent fuel management strategy which requires only on-site storage of a fraction of the fission products produced during reactor operation. Electro-refining separation of selected fission products combined with complete actinide recycling yields no isolation of plutonium or highly enriched uranium during the procedure. The out-of-core waste stream has a significantly reduced radioactivity, volume and lifetime compared to the once-through waste management strategy and thus provides an alternative to long-term geological disposal of fission reactor wastes. The Pellet Suspension Reactor concept possesses some unique operating characteristics and, additionally, is shown to be similar to conventional fission reactors in terms of common performance features.
|
|Appears in Collections:||Open Access Dissertations and Theses|
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Source: Mehr News Agency, Tehran
President Mahmoud Ahmadinejad said on Tuesday that Iran had no alternative other than enriching uranium to a purity level of 20 percent after the West refused to sell the needed nuclear fuel to Iran to operate its research nuclear reactors which produce radioisotopes for medical patients.
Source: Iran Daily
"They refused Iran's request. We insisted and again they did not," Ahmadinejad told a press conference in Tehran.
"We were even ready to give 3.5 percent (enriched) fuel to the West and take 20 percent fuel but again they were not ready to do it therefore we were forced to start enriching uranium to the degree of 20 percent," Ahmadinejad explained.
He added Iran is still willing to stop enriching uranium to 20 percent if International Atomic Energy Agency members sell the needed fuel to Iran.
"So far nobody has announced readiness to sell 20 percent (enriched) fuel to Iran, but anytime they give us this fuel we will feel no need to produce the costly fuel of 20 percent."
... Payvand News - 10/03/12 ... --


This Radiation is Okay because it is Natural
I have heard this statement before and it came to mind again this morning when I read the following in a news article “Like all radioactive material, the gamma radiation from Cobalt-60 can cause cancer if ingested by humans, especially if it occurs due to leaks from the nuclear plant that can cause contamination in water bodies.”
The statement made me shake my head and smile at the same time. Let’s break down the statement. I first have to admit, though, that I don’t know what “water bodies” are. Perhaps they are bodies of water – like a lake or pond? I’m not sure.
The statement is true insofar as gamma radiation from cobalt-60 has the potential to cause cancer if ingested by humans. The cancer risk is not increased; however, if it is cobalt-60 in leaking coolant from nuclear power plants. If it is liquid cobalt-60, it is liquid cobalt-60. It doesn’t matter where it comes from.
The amount of cobalt-60 does matter. But, if you have X amount of radioactivity in nuclear power coolant and that same amount of radioactivity in a research laboratory, it carries the same potential risk if it is all ingested.
The same principle applies when it comes to volumes of liquid – I say this because of other news items I’ve read. If you have X amount of radioactivity in a glass of water and that same amount of radioactivity in a backyard pool, if you drink all the water in the glass or all the water in the pool, the radioactivity carries the same potential risk.
I spoke to a reporter about this one time. He said that over 300,000 gallons of water were contaminated with a radioactive material. He thought this sounded very hazardous. I asked him how much radioactive material was in the water. He didn’t know, but he knew that 300,000 gallons of water were contaminated. I tried to explain that the 300,000 gallons of water didn’t matter – that the amount of radioactive material present is what posed the risk. A bit like dropping an Alka Seltzer® in a glass of water versus this 300,000 gallons – the amount makes a big difference.
So, let’s always start on the same ground when we read statements like the one in the first paragraph. Let’s ask “What is the amount of the radioactive material?” and “What is the potential risk from that amount of radioactive material?” When you receive an answer like “Well, there are 300,000 gallons of contaminated water,” recognize that this is not the answer to your questions.