Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 50099 | 8 May 2014 15:24:00 | 10 CFR 76.120(c)(2) | High Pressure Fire Water Sprinkler System B-6 Declared Inoperable | At 1024 CDT, on 05-08-2014, the Plant Shift Superintendent was notified that the C-333 High Pressure Fire Water (HPFW) Sprinkler System B-6 had been inspected by Fire Services and 5 sprinkler heads had visible corrosion or paint on them, including 2 heads adjacent to each other. The system configuration was evaluated using EN-C-822-99-047 (Engineering Notice), 'Effects of Impaired Sprinkler Heads on System Operability' and determined that with these heads potentially impaired, a portion of the building would not have sufficient sprinkler coverage. The HPFW system is required to be operable according to TSR LCO (Technical Safety Requirement Limiting Condition for Operation) 2.4.4.5. HPFW Sprinkler System B-6 was declared inoperable and TSR LCO 2.4.4.5 Required Action B was implemented for the area without sprinkler coverage. Based on past testing results, there is a possibility that the heads would have been able to perform their specified safety function. Once the heads are removed from the system, testing will be performed to determine the actual effect on operability. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed. The NRC Region II (Marvin Sykes) has been notified of this event. PGDP Assessment and Tracking Report No. ATR-14-0444; PGDP Event Report No. PAD-2014-05; NRC Worksheet No. 50099; Responsible Division: Operations.
Subsequent to the event, the corroded sprinkler heads were replaced with new heads and the removed heads were tested in the laboratory. Based on the test results, one of the adjacent heads that was potentially impaired was determined to be fully functional and in accordance with EN-C-822-99-047, HPFW Sprinkler System B-6 was capable of performing its intended safety function. Since this event does not meet the criteria for a reportable event under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed, the event notification is being retracted. The NRC Region II (Marvin Sykes) has been notified of this retraction. Notified the R2DO (Desai) and NMSS EO (Csontos). | ||
| ENS 49953 | 24 March 2014 01:50:00 | 10 CFR 76.120(c)(2) | Safety Equipment Potential Failure - High Pressure Fire Water Sprinkler System | At 2050 CDT, on 03-23-2014, the Plant Shift Superintendent was notified that the C-333 High Pressure Fire Water (HPFW) Sprinkler System A-16 had been inspected by Fire Services and 11 sprinkler heads had visible corrosion on them, including 4 heads adjacent to each other. The system configuration was evaluated using EN-C-822-99-047, 'Effects of Impaired Sprinkler Heads on System Operability' and determined that with these heads potentially impaired, a portion of the building would not have sufficient sprinkler coverage. The HPFW system is required to be operable according to (Technical Safety Review) TSR LCO 2.4.4.5. HPFW system A-16 was declared inoperable and TSR LCO 2.4.4.5 Required Action B was implemented for the area without sprinkler coverage. Based on past testing results, there is a possibility that the heads would have been able to perform their specified safety function. Once the heads are removed from the system, testing will be performed to determine the actual affect on operability. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed. The NRC Region II (Marvin Sykes) has been notified of this event. PGDP Assessment and Tracking Report No. ATR-14-0324; PGDP Event Report No. PAD-2014-03; NRC Worksheet No. 49953 Responsible Division: Operations TSR LCO 2.4.4.5 Action B requires an hourly fire patrol in the affected area.
Subsequent to the event, the corroded sprinkler heads were replaced with new heads and the removed heads were tested In the laboratory. Based on the test results and the operability criteria defined in EN-C-822-99-047, A-16 was capable of performing its intended safety function. The clustered heads were on a single branch line in a ceiling beam pocket. The middle head failed testing, however overlapping coverage was provided by the adjacent heads on both sides. Notified R2DO (Sykes). | ||
| ENS 49918 | 14 March 2014 18:30:00 | 10 CFR 76.120(c)(2) | High Pressure Fire Water Systems Declared Inoperable | On 3/14/2014 at 1330 hours, the Plant Shift Superintendent was notified by Fire Services that adequate pressure could not be verified during post maintenance testing of an inoperable High Pressure Fire Water System for the C-335 building. During investigation into the issue, it was discovered that eleven operable High Pressure Fire Water Systems were also impacted. The facility is in TSR mode three as all cells have been sampled UF6 negative and the cell motors are not energized. In this mode, the High Pressure Fire Water Systems are still required to be operable per TSR 2.4.4.6; however, due to inadequate pressure, the eleven systems may not have been able to perform the intended safety function. The eleven operable High Pressure Fire Water Systems were declared inoperable and hourly fire patrols were initiated according to TSR LCO 2.4.4.5.9.1 at 1520 hours on 3/14/2014. On 2/26/2014 at 1212 hours, three High Pressure Fire Water System Sectional Valves were isolated and declared inoperable in order to isolate a section of header which contained a small leak. Isolating these valves resulted in a single supply to twelve High Pressure Fire Water Systems in C-335. Upon investigation of the lack of pressure, it was determined that the sectional supply valve in the remaining supply loop was not operating as designed and is suspected to be the cause of the restricted water flow. Sectional supply valves that had been used for isolation of the small leak have been opened to provide unrestricted flow to the affected sprinkler systems. Following the confirmation of adequate flow, the sprinkler systems were declared operable and the hourly fire patrols were discontinued at 1739 hours on 3/14/2014. The small leak will be monitored until repairs can be initiated or the leak becomes unmanageable. At that point TSR LCO actions will be entered as necessary. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Region II (Marvin Sykes) has been notified of this event via voice mail. | ||
| ENS 49544 | 17 November 2013 20:17:00 | Other Unspec Reqmnt 10 CFR 76.120(a)(4) | Alert Due to Storm Damage on Site | On 11/17/13, at 1417 CST, an alert was declared at the Paducah Gaseous Diffusion Plant due to an apparent tornado strike/severe weather event. Multiple facilities were damaged with no injuries and no hazardous material released. No damage to the security fence was observed and the protected area remained secured during the event. This event is reportable under 10 CFR 76.120(a)(4) where an emergency condition has been declared an Alert. NRC Branch Chief has been notified. PGDP has no NRC Resident Inspector. PGDP Event Report No. PAD-2013-08. Notified DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.
On 11 /17/13, at 1638 CST, the Paducah Gaseous Diffusion Plant decided to issue press releases describing the Alert issued by the plant that afternoon. The Alert was declared due to an apparent tornado strike/severe weather event on 11/17/13 at 1417 CST. This event is reportable under Criteria P in Appendix D of USEC procedure CP2-RA-RE 1 030 as any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. NRC Branch Chief has been notified. PGDP has no resident inspector. PGDP Event Report No. PAD-2013-08. Notified RA (McCree), NMSS EO (Damon), R2DO (Desai), IRD (Gott), NMSS (Haney), DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.
The Alert was terminated at 1806 CST on 11/17/13 after a complete security check of the site perimeter and a compilation of the damages sustained by the site. There were no personnel injuries and no releases (HAZMAT or radiological). Notified RA (McCree), NMSS EO (Damon), R2DO (Desai), IRD (Gott), NMSS (Haney), DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email. | ||
| ENS 48680 | 23 December 2012 05:20:00 | Other Unspec Reqmnt | Minor Incidental Uranium Hexafluoride Release | Note this is a late report (1/17/2013). During December 2012, the C-360 Toll Transfer and Sample building experienced three incidents where the Laboratory Process Gas Leak Detection (PGLD) system was actuated. No visible smoke was ever seen. Subsequent bioassay samples of personnel in the area confirmed that minor exposures did occur, although no work restrictions were required. The exposures confirm that the PGLD actuations were due to actual minor incidental uranium hexafluoride releases. Investigation and testing found that the first two incidents were caused by a small pinhole leak in instrument tubing and the third incident was caused by slight leakage around the stem of a small instrument valve. These three events were evaluated for reportability at the time they occurred, but it was determined they did not meet our reporting criteria. However, after further evaluation and discussion with NRC staff, USEC is conservatively reporting the incidents. The actuations occurred on December 22, 23, and 29, 2012. Upon each actuation, the system automatically closed the appropriate valves as designed. Response to each leak consisted of atmospheric sampling for HF and radiological swipes per procedure along with precautionary bioassay samples. The atmospheric sampling and radiological swipes on the first release were negative and the system was returned to service. The second incident the next day was similar to the first and again the immediate samples were negative. Bioassay results were then obtained from the previous night and showed a detectable exposure. With confirmation of a small leak, helium leak detection was utilized to find the small pinhole leak. The third incident was due to slight leakage around a valve stem that was discovered by soap testing the valve and evidence of some visible oxides on the valve stem. These types of releases are incidental and do not have the potential for impact on the health and safety of personnel or the public. These incidents are being conservatively reported as a 24-hour event based on SAR 6.9 Table 1, J.2 as an Unplanned Actuation of a Q Safety System." An automatic or manual actuation of a Q safety system that results from an event or condition that has the potential for significant impact on the health or safety of personnel. Events having the potential for significant Impact are those events where actual plant conditions existed that the system was designed to protect against. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 48522 | 19 November 2012 22:25:00 | 10 CFR 76.120(c)(2) | Uninterruptible Power Supply Safety Equipment Failure | At 1625 CST on 11-19-12, Electrical Maintenance and Power Operations were in the process of changing a circuit breaker in the C-409 facility which supplies power to the C-409 Criticality Accident Alarm System (CAAS) Uninterruptable Power Supply (UPS). This UPS supplies power to the C-409 CAAS horns. Procedure CP2-CO-ON3031 was being utilized and the CAAS Horn Power UPS was being monitored continuously to maintain the CAAS operable. As soon as the breaker was opened it was identified that the UPS failed to throw over to battery power. At that point the breaker was re-closed and AC power restored to the CAAS horns. The time that AC power was off the CAAS horns was approximately 3-5 seconds. There were no fissile material operations in progress in the C-409 facility. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR (Technical Safety Requirements) to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 48022 | 12 June 2012 20:45:00 | 10 CFR 76.120(c)(2) | Safety Equipment Failure - Criticality Air Horns Not Tested for Audibility | While reviewing Maintenance Work Package 'Performance of the C-335 Annual CMS Surveillance' from April 28, 2012 an error was identified. Procedure 'C-335 CMS Maintenance And Testing' requires an audibility check if the as-found values for the regulator air pressure drift feeding the Criticality Accident Alarm System (CMS) air horns is >?12 psig. However, an audibility check was not performed as required at six locations all on the cell floor of the process building that were discovered to be out-of-tolerance. All air pressure regulators were adjusted to within acceptable-as-left tolerances prior to the system being made operable on April 28. Without the audibility testing being performed, the audibility of the C-335 CMS was questionable prior to the April testing. On June 13, 2012, a work package was developed to recreate the pressures encountered on April 28 and to test the audibility of the CMS. Subsequent testing has shown that three of the CMS horns fed by out-of-tolerance pressure regulators may not have provided the required sound levels necessary for audibility in those areas. This is failure of safety equipment required by TSR 2.4.4.2. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2), 'An event in which equipment is disabled or fails to function as designed when: (i) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; (ii) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand; and (iii) no redundant equipment is available and operable to perform the required safety function.' The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-12-1496; PGDP Event Report No. PAD-2012-03; Responsible Division: Operations
Subsequently, the C-335 CAAS air horns have been tested in the as-found conditions from April 28, 2012. Using the original design audibility criteria in the most limiting condition, the CAAS horn audibility was found to be acceptable. Therefore, the system would have been able to perform its intended safety function in the April 28, 2012, as-found condition. Based on the testing and an engineering evaluation, the event notification is being retracted. The licensee has notified the NRC Resident Inspector. Notified R2DO (Calle) and NMSS (Silva). | ||
| ENS 47911 | 8 May 2012 21:16:00 | 10 CFR 76.120(c)(2) Response | Autoclave High Pressure Isolation System Failure | At 1616 CDT, on 05-08-12 the Plant Shift Superintendent (PSS) was notified that C-360 (Toll Transfer & Sampling Building) Autoclave #2 had a failure in the Autoclave High Pressure Isolation System (AHPIS). (AHPIS) is designed to: 1) prevent a cylinder failure inside the autoclave as a result of overheating; and 2) mitigate releases to the atmosphere from releases inside the autoclave. Autoclave containment is required to be operable per TSR 2.1.3.1 while the autoclave is in TSR modes 3 (containment), 4 (autoclave closed), and 5 (autoclave heating). On 5/08/12 at 1610 CDT an operator noticed water flowing from the autoclave head to shell sealing surface on the #2 autoclave in C-360 while a cylinder was being heated (TSR mode 5 - autoclave heating). The PSS was notified of the loss of containment at 1616 CDT and the (AHPIS) was declared inoperable. The steam cycle was interrupted and the autoclave was placed in a non-applicable TSR mode at 1657 CDT. No release of UF6 occurred due to the failure of the (AHPIS). This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand; and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-12-1195; PGDP Event Report No. PAD-2012-02; Responsible Division: Operations
After further review the licensee determined that additional reportability criteria were met as described below: At 1616 on 05/08/2012, the PSS was notified that C-360 Autoclave #2 had water flowing from the autoclave head to shell sealing surface indicating a potential failure in the Autoclave High Pressure Isolation System (AHPIS) containment, which is relied on as an engineered control in NCSE 042 (SRI 5.5.3). The AHPIS is designed to minimize leaks to atmosphere from the autoclave under maximum pressures resulting from a UF6 release from the cylinder, valve or pigtail in the autoclave. The maximum acceptable leak rate for the autoclaves is 12 SCFM at a minimum test pressure of 90 psig or a 10 psi pressure drop in 1 hour. In order to determine if the AHPIS would have met its safety function, a pressure decay test will be performed. However, the pressure decay test will not be performed within 24 hours of discovery. Therefore, it is conservatively assumed that the leak discovered is greater than 12 SCFM or greater than 10 psi pressure drop in 1 hour; resulting in a 24 hour NCS reportable event. When the leak was noticed, the heat cycle was interrupted and the autoclave placed in a safe configuration. No release of UF6 had occurred in the autoclave when the leak out the autoclave was found. This event is reportable as a 24 hour event in accordance with 24-Hr. NRC BL 91-01 Supp. 1. This is a criticality safety event in which violations involving operations that comply with the double contingency principle and do not meet the criteria for a 4-hr report, but still result in a violation of the double contingency principle, such as, events where the double contingency principle is violated but control is immediately reestablished. Safety Significance of Events: --While an NCSA control was not maintained resulting in the potential autoclave leak rate being exceeded, a release of fissile material from a cylinder in the autoclave did not occur and therefore a criticality was not possible. Potential Criticality Pathways Involved: --In order for a criticality to be possible, a cylinder, valve, or pigtail of a fissile cylinder would have to fail and release greater than a safe mass of fissile material into the autoclave and the autoclave containment would have to fail allowing a large release to atmosphere of uranium and settle out in an unfavorable geometry with sufficient moderator present. Controlled Parameters: --The first leg of double contingency is based on mass. --The first leg of double contingency is based on administrative and design controls to ensure that it is unlikely to have a large release of UF6 from the cylinder, valve or pigtail in the autoclave while healing the cylinder. --The second leg of double contingency is based on geometry moderation. Estimated Amount, Enrichment, Form of Licensed Material: --No leakage of UF6 occurred. Nuclear Criticality Safety Control(s) or Control System(s) and Description of the Failures or Deficiencies: --The first leg of double contingency is based on mass. --The first leg of double contingency is based on administrative and design controls to ensure that it is unlikely to have a large release of UF6 from the cylinder, valve or pigtail in the autoclave while heating the cylinder. This control was maintained. --The second leg of double contingency is based on geometry / moderation. --Small leaks out of the autoclave to atmosphere are considered normal case and the Autoclave High Pressure Isolation System ensures containment to minimize a significant release to atmosphere if a release occurs in the autoclave during heating. The AHPIS ensures that the maximum leak rate from the autoclave will not exceed 12 SCFM or a maximum acceptable pressure drop of 10 psi in 1 hour. If the containment leak rate is maintained, only a small amount of uranium could leak to atmosphere and the uranium would form in thin layers on surfaces in a geometrically safe configuration. Also there would be insufficient uranium to leak outside of the building; therefore there would not be a sufficient source of moderation. Since this control is assumed to have failed, uranium could leak out of the autoclave to atmosphere if a large release of UF6 occurred in the autoclave and potentially deposit in geometrically unfavorable configurations in areas where sufficient moderators exist. Since the leak rate cannot be confirmed within 24 hours, it is conservatively assumed that the geometry moderation parameter was lost and double contingency was not maintained. Corrective Actions To Restore Safety Systems and When Each Was Implemented: --Perform a pressure decay test on Autoclave #2 according to procedures and if the leak rate is determined to be greater than 12 SCFM or 10 psi in one hour, repair AHPIS prior to heating another cylinder containing uranium. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-12-1195; PGDP Event Report No. PAD-2012-03; Responsible Division: Operations. Notified R2DO (Freeman) and NMSS EO (Campbell).
Subsequent to the above notifications on May 10, 2012, autoclave no. 2 was subjected to a pressure decay test in the as-found condition. The test indicated that the High Pressure Isolation Safety System would have been capable of performing its intended safety function if called upon on May 8, 2012, during the heat cycle subject of the event reports. Thus, the event was not required to be reported under 10CFR 76.120(c)(2)(i) and the notifications may be retracted. Subsequent to the above notifications on May 10, 2012, autoclave no. 2 was subjected to a pressure decay test in the as-found condition. The test indicated that the High Pressure Isolation Safety System would have been capable of performing its intended safety function if called upon on May 8, 2012, during the heat cycle subject of the event reports. The pressure drop from the as-found test was less than the maximum allowable pressure drop for the system required for criticality safety. Thus, the event did not meet the criteria to be reported under 24-Hr. NRC BL 91-01 Supp. 1. The NRC Senior Resident Inspector has been notified of this event. Notified R2DO (Shaeffer) and NMSS EO (Guttmann). | ||
| ENS 47531 | 17 December 2011 06:01:00 | 10 CFR 76.120(c)(2) | Possible Degradation in High Pressure Fire Water Sprinkler Heads | At 0001 CST, on 12-17-2011, the Plant Shift Superintendent was notified that the C-310 High Pressure Fire Water (HPFW) Sprinkler System #2 had been inspected by Fire Services and thirty-two (32) sprinkler heads had visible corrosion on them. The system configuration was evaluated using EN-C-822-99-047, 'Effects of Impaired Sprinkler Heads on System Operability' and determined that with these heads potentially impaired, a portion of the building would not have sufficient sprinkler coverage. The HPFW system is required to be operable according to TSR LCO 2.4.4.5. C-310 HPFW system #2 was declared inoperable and TSR LCO 2.4.4.5 Required Action B was implemented for the area without sprinkler coverage. Based on past testing results, there is a possibility that the heads would have been able to perform their specified safety function. Once the heads are removed from the system, testing will be performed to determine the actual affect on operability. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed." The site instituted compensatory measures included performing a fire patrol walkdown of the area within the first two hours after discovery of the potential degradation and hourly fire patrols thereafter. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 47376 | 26 October 2011 18:20:00 | 10 CFR 76.120(c)(2) | 24 Hour Report Due to Detection of Linear Defect in Surge Volume Accumulator | At 1320 CDT, on 10-26-11 the Plant Shift Superintendent (PSS) was notified that the C-310 Side Accumulator had a linear defect in the vessel shell that caused a UF6 release on 10-21-2011. The UF6 liquid accumulators serve the product withdrawal system. The side accumulator is a monel tank used in the product withdrawal system to provide a surge volume. The safety function of the side accumulator is to provide UF6 primary system integrity for the withdrawal process that contains a gaseous and liquid UF6. TSR 2.3.5.6 is a design feature that requires the withdrawal area UF6 condensers and accumulator vessels to have a minimum required metal thickness in accordance with ASME requirements to prevent UF6 releases. There are no LCO actions associated with this TSR but there is a 5 year surveillance requirement to perform a visual inspection including thickness measurements. The side accumulator was in service when a small UF6 release occurred on 10-21-2011. The release was contained to the immediate area and the side accumulator was taken out of service for investigation and subsequent repairs. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident has been notified of this event. PGDP Assessment and Tracking Report No. ATR-11-2856; PDGP Event Report No. PAD-2011-19. | ||
| ENS 47307 | 30 September 2011 13:10:00 | Other Unspec Reqmnt | Hydraulic Leak Contained on Site- State Officials Notified | |||
| ENS 47099 | 27 July 2011 09:15:00 | Other Unspec Reqmnt 10 CFR 76.120(a)(4) | Alert Declared Due to Onsite Release of Fluorine/Chlorinated Fluorine Gas Mixture | At 0415 CDT while changing out a cylinder of Fluorine/CL3 gas mixture in the C350 building, apparently a gasket failure occurred and an uncontrolled release of the gas mixture began. The licensee estimates that at the time the release began, there was approximately 160 lbs. of material in the cylinder. The release continues at this time. The C350 building was evacuated. There were no personnel injuries as a result of this event. No offsite assistance is being requested by the licensee. The local emergency squad is responding. The licensee notified the NRC Resident Inspector.
The licensee believes, but has not verified at this time, that the gas leak has been stopped. A 'shelter in place' order has been issued for the following buildings: C337, C337a, C360, C335, C635 and C631. Samples exterior to building C350 are negative. Samples interior to building C350 still show residue and fog in the building. The licensee notified the NRC Resident Inspector.
The licensee has verified that the leak has been stopped.
At 0615 CDT, an employee that was involved with the cylinder change-out and response to the event was transported to the onsite medical facility. He was complaining of a burning sensation to his right arm. At 0625 CDT, samples obtained both inside and outside of building C350 were negative. The licensee notified the NRC Resident Inspector.
At 0631 CDT, the licensee has terminated the Alert. The licensee is controlling access to building C350 for investigation. The licensee has setup a recovery team. As a precautionary measure, a second individual that was involved in the cylinder change-out was also transported to the onsite medical facility. The licensee notified the NRC Resident Inspector. Notified R2DO (Blamey), NMSS EO (Habighorst), IRD MOC (Marshall), DHS (Arnold), FEMA (Hollis), DOE (Connally), EPA (Brett), USDA, and HHS (Jones).
On 7/27/11 at 0710 (CDT), the Paducah Gaseous Diffusion Plant decided to issue a press release describing the Alert issued by the plant earlier in the morning. The Alert issued on a chlorine trifluoride (CIF3) release in the C-350 facility was declared on 07/27/11 at 0415 (CDT) and terminated on 07/27/11 at 0631 (CDT). . This event is reportable under Criteria P in Appendix D of USEC procedure UE2-RA-RE1030 as any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. The NRC Senior Resident Inspector has been notified of this event. Notified R2DO (Blamey), NMSS EO (Habighorst) and PAO (Harrington). | ||
| ENS 46996 | 28 June 2011 05:05:00 | 10 CFR 76.120(c)(2) | Failure of #2 Fire Water Pump to Realign | At 0005 CDT, on 06-28-2011, the Plant Shift Superintendent was notified that the C-631 High Pressure Fire Water (HPFW) pumps #2 and #3 automatically started in response to low HPFW header pressure created by a line leak and rendered inoperable. Following isolation of the water leak the #2 and #3 pumps were shut down and were being configured for automatic start. The RCW operator observed the 'Auto Start' Indicator for the #2 pump was not illuminated. The pump was declared inoperable and power was removed from the #2 pump for troubleshooting and repair by electrical maintenance (EM). When power was removed from the pump the HPFWS could not perform its intended safety function of providing 4875 gpm. Two HPFW system pumps are required to be operable according to TSR LCO 2.4.4.8. EM reset a disconnect interlock switch which reenergized the 'Auto Start' controls and the pump was declared operable and returned to service. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed. The NRC Senior Resident Inspector has been notified of this event. * * * UPDATE FROM KEVIN BEASLEY TO PETE SNYDER AT 1613 EDT 6/29/11 * * * Due to the uncertain nature of the leak on the 16 inch underground High Pressure Fire Water (HPFW) distribution main, it is not known at this time if the two operable HPFW pumps would have been able to satisfy the maximum sprinkler system demand of 4875 gpm. Upon completion of excavating the area of the leak, Engineering will evaluate the failure mode to determine if system requirements were maintained. The licensee notified the NRC Resident Inspector. Notified R2DO (M. Franke) and NMSS (R. Johnson). * * * RETRACTION FROM CALVIN PITTMAN TO KARL DIEDERICH AT 1423 EDT 07/14/11 * * * Upon further evaluation it was determined that the (High Pressure Fire Water System) HPFWS was capable of fulfilling its intended safety function at all times during the incident. The safety function of the High Pressure Fire Water System established in SAR 3.15.7.2 is to provide sufficient fire suppression capability for the cascade process buildings to minimize the likelihood of a large fire. Fire scenarios were evaluated to establish the system design basis. A lube oil spill fire on the operating floor resulted in the highest sprinkler flow rate demand of 3200 gpm. A 500 gpm hose stream demand is added to the sprinkler system flow rate to obtain a maximum fire water flow rate of 3700 gpm for the evaluation basis fire event. As stated in the TSR 2.4.4.8 Basis Statement, the requirements for HPFWS operability established in TSR 2.4.4.8 are conservative with respect to the system evaluation presented in SAR 3.15.7.2. TSR SR 2.4.4.8-4 requires an annual flow rate verification of each HPFW pump. The most recent flow rate tests performed in Nov. 2010 demonstrate the capacity of each pump exceeds the evaluation basis flow demands. During the short time where only HPFW pump #3 was operable, this pump could have supplied more than the 3700 gpm required to satisfy the evaluation basis flow demand. The HPFWS remained capable of fulfilling its intended safety function. In addition, when HPFW pumps #2 and #3 were running in response to the leak on the underground distribution system, system pressure was approximately 134 psig. Using the pump curves established by the annual TSR surveillance test discussed above, this equates to a flow rate of approximately 5900 gpm. Any sprinkler system activation on the HPFWS would drop the system pressure to around 125 psig, slightly lowering the flow rate through the leak. During the time frame the leak was active, the HPFWS remained capable of fulfilling its intended safety function. The combined pump capacity of pumps #2 and #3 (10,600 gpm) demonstrated by the annual surveillance test exceeds the combined demand from the leak (5900 gpm) and the evaluation basis flow requirements (3700 gpm). Therefore, the HPFWS remained operable throughout the incident of the underground piping leak and the following time period of only one pump operable. Thus, reporting per 10 CRF 76.120 was not required and the subject notification can be retracted. The NRC Senior Resident Inspector has been notified of this retraction by the licensee. Notified R2DO (Freeman) and NMSS (Rahimi). | ||
| ENS 46853 | 15 May 2011 17:54:00 | 10 CFR 76.120(c)(2) | Portion of High Pressure Fire Water System Declared Inoperable | At 1254 CDT, on 05/15/2011, the Plant Shift Superintendent was notified that the C-333 High Pressure Fire Water (HPFW) Sprinkler System C-14 had been inspected by Fire Services and eleven sprinkler heads had visible corrosion on them. The system configuration was evaluated using EN-C-822-99-047, 'Effects of Impaired Sprinkler Heads on System Operability' and determined that with these heads potentially impaired, a portion of the building would not have sufficient sprinkler coverage. The HPFW system is required to be operable according to TSR LCO 2.4.4.5. HPFW system C-14 was declared inoperable and TSR LCO 2.4.4.5 Required Action B was implemented for the area without sprinkler coverage. Based on past testing results, there is a possibility that the heads would have been able to perform their specified safety function. Once the heads are removed from the system, testing will be performed to determine the actual affect on operability. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed. The NRC Senior Resident Inspector has been notified of this event. PGDP (Paducah Gaseous Diffusion Plant) Assessment and Tracking Report No. ATR-11-1192; PGDP Event Report No. PAD-2011-08; Responsible Division: Operations An hourly fire patrol is being conducted in the affected area. (Licensee) estimated correction date: 5/20/2011.
Subsequent to the event, the corroded sprinkler heads were replaced with new heads and the removed heads were tested in the laboratory. Testing by the laboratory has shown that six of the 10 removed sprinkler heads would have performed their safety function, five of the heads would not have performed their safety function, but these heads would not affect the system operability. The conclusion of the tests is that the C-333 sprinkler system C-14 would have performed its intended safety function if called upon. The NRC Senior Resident Inspector has been notified of this retraction. Notified R2DO(Shaeffer) and NMSS EO(Damon) | ||
| ENS 46487 | 17 December 2010 15:37:00 | Other Unspec Reqmnt | Diesel Fuel Oil Spill Contained on Site - Federal and State Officials Notified | At 0937 CST, 12/17/2010, the Kentucky Emergency Response Team (Report Number 2321984), the Kentucky Department for Environmental Protection, and the National Response Center (Report Number 962502) were notified of the following issue: a diesel fuel oil leak occurred from a pressure indicating line from storage tank located at (Bldg) C-600. The amount of diesel fuel that leaked from the storage tank is greater than the reportable quantity of 75 gallons. The secondary containment drain valve leaked which allowed the diesel fuel to reach the oil containment underflow dam at outfall 008. The diesel fuel is currently contained in the oil containment underflow dam. The effluent from outfall 008 has been tested and does not contain any detectable diesel fuel. Additionally, no visible sheen was observed from the effluent from outfall 008. Cleanup of the diesel fuel is in progress. This event is reportable as 'USEC shall notify NRC of any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. Such an event may include an on-site fatality or inadvertent release of radioactively contaminated materials.' The NRC Resident Inspector has been notified of this event. PGDP Event Report No. PAD-2010-13. | Secondary containment | |
| ENS 45890 | 30 April 2010 15:15:00 | 10 CFR 76.120(c)(2) | Tar Found on Overpressure Rupture Discs Potentially Changing the Relief Set Point | On 04/30/10 the Plant Shift Superintendent (PSS) was notified that while performing maintenance on C-337 Unit 2 Cell 4 Odd R-114 rupture disc replacement, roofing tar was discovered in the upper rupture disc. C-337 U/2 C/4 Odd system was not in a mode of applicability according to TSR (Technical Safety Requirement) 2.4.3.4. The presence of the roofing tar on an operable R-114 coolant overpressure control system rupture disc would not allow the rupture disc to perform its intended safety function as required by TSR 2.4.3.4. The R-114 rupture disc is the primary component of the R-114 coolant overpressure control system. The R-114 coolant overpressure control system prevents excess coolant pressure from rupturing the coolant system and releasing coolant into the UF6 primary system that could result in the subsequent release of UF6 due to over pressurization of the UF6 system. TSR 2.4.3.4 and 2.3.3.2 require that the R-114 coolant overpressure control system be operable. An extent of condition inspection of in use R-114 rupture discs is in progress. Roofing tar was discovered on R-114 coolant overpressure control system rupture discs in the following locations: C-337 cells U/3 C/2 Odd, U/1 C/5 Odd, U/1 C/6 Odd, U/6 C/4 Odd, U/2 C/5 Even, U/5 C/4 Odd, U/5 C/6 Even, U/5 C/8 Odd, U/4 C/7 Even (Not in an applicable mode), U/2 C/4 Odd (Not in an applicable mode). U/6 C/7 Odd (Not in an applicable mode). C-331 U/1 C/4 (Not in an applicable mode). Buildings C-310 and C-335 R-114 coolant overpressure control system rupture discs were inspected and were free of any foreign material. Systems that are in an applicable mode according to TSR 2.4.3.4 and were discovered to have roofing tar on the rupture discs were declared inoperable and an operator was stationed to continuously monitor the R-114 pressure in order to take action according to TSR 2.4.3.4. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-l0-1131; PGDP Event Report No. PAD-2010-6
On 05-01-2010 at 2225 hours, extent of condition walk downs have been completed. Additional R-114 rupture disc locations were discovered with either roofing tar and/or shipping caps in the upper rupture disc. The presence of either would not allow the R-114 rupture disc to perform its intended safety function as required by TSR 2.4.3.4. Systems that are in an applicable mode according to TSR 2.4.3.4 and were discovered to have roofing tar and/or shipping caps on the upper rupture discs were declared inoperable and an operator was stationed to continuously monitor the R-114 pressure in order to take action according to TSR 2.4.3.4." The licensee provided a list of 28 cells that had shipping caps installed and 13 cells with roofing tar on the discs. The NRC Senior Resident Inspector has been notified of this event.
On 5/02/2010 at 0636 hours during a review of the extent of condition inspection notes, engineering identified that C-333 U/4 C/9 Even R-114 Over-pressurization system had been omitted from the report due to oversight. Engineering had identified a shipping cover with tar on it was present on the rupture disc. The NRC Senior Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-10-1141; PGDP Event Report No. PAD-2010-6. Responsible Division: Operations Notified R2 DO (Randy Musser) and NMSS EO (Tim McCartin) | ||
| ENS 45800 | 29 March 2010 13:08:00 | 10 CFR 76.120(c)(2) | Safety Equipment Failure - Process Gas Detection System Found Inoperable | At 0808 CDT on 03-29-10, the Plant Shift Superintendent (PSS) was notified that C-333 Unit 5 Cell 6 Process Gas Detection System (PGLD) was found with the READY light not illuminated when Operations were performing the manual test firing required by TSR surveillance requirement SR 2.4.4.1-1. This PGLD System contains detectors that cover Unit 5 cell 6 cell housing and Section 3 of the cell bypass piping. At the time the READY light was discovered not illuminated, these areas were operating above atmospheric pressure. The PGLD System was declared inoperable, TSR LCO 2.4.4.1.A.1 and 2.4.4.1.C.1 were entered and a continuous smoke watch was put in place within one hour. The power supply module was replaced and the system was satisfactorily tested. The system was declared operable at 1030 CDT on 03-29-10. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell housing and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 5 Cell 6 PGLD system inoperable, none of the required cell housing heads were operable. A PGLD head was manually actuated ('smoke tested') and the system would not alarm. Engineering has determined that the system would not have been able to perform its intended safety function. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 45629 | 13 January 2010 14:50:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection System Inoperable | At 0850 CST, on 1-13-10 the Plant Shift Superintendent (PSS) was notified that the C-333 B-Booster UF6 Release Detection (PGLD) system was inoperable due to loss of power to the system. The purpose of the PGLD System is to detect a UF6 release and alert operators in the ACR by sounding an alarm. At the time this was discovered, some areas covered by this PGLD system were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the areas covered by this PGLD system are operable during steady state operations above atmospheric pressure. With the B-Booster PGLD system inoperable, none of the required heads were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.D.1 and 2.4.4.1.E.1 were entered, and a continuous smoke watch was put in place within one hour. An investigation was initiated and it was determined that power was interrupted during planned maintenance activities and there was a failure to identify that the power supply to this PGLD system would be impacted prior to performing the maintenance. Power was restored and the system was tested and declared operable at 1542 hours. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 45527 | 29 November 2009 00:50:00 | 10 CFR 76.120(c)(2) | Safety Equipment Disabled Due to a Ground in the Area Control Room Alarm | At 1850 CST, on 11/28/09 the Plant Shift Superintendent (PSS) was notified that the C-333 Unit 6 Cell 5 UF6 Release Detection (PGLD) System was inoperable due to loss of power to the Area Control Room (ACR) alarm for this system. The purpose of the PGLD System is to detect a UF6 release and alert operators in the ACR by sounding an alarm. At the time this was discovered, G-333 Unit 6 Cell 5 was operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 5 PGLD system inoperable, none of the required heads were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 was entered and a continuous smoke watch was put in place within one hour. Troubleshooting was initiated, a ground was discovered on the alarm circuit, the ground was isolated, and the system was tested and declared operable at 2305 (CST). This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. | ||
| ENS 45365 | 19 September 2009 18:23:00 | 10 CFR 76.120(c)(2) | High Voltage Process Gas Leak Detector Rendered Inoperable | At 1323 CST, on 09-19-09 the Plant Shift Superintendent (PSS) was notified that C-315 (Tails Withdrawal facility) High Voltage Process Gas Leak Detector (PGLD) YE-10-2-6 was rendered inoperable during asbestos abatement activities. This PGLD system contains detectors that cover the C-315 UF6 condensers, accumulators, and piping heated housing. At the time of this failure, these areas were operating above atmospheric pressure. TSR 2.3.4.4 requires that all detector heads in this system be operable during operations above atmospheric pressure. This PGLD System was declared operable and returned to service at 1359 hours, which is within the one hour required by TSR LCO 2.3.4.4.A.1 to enter a continuous smoke watch. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. Once the reason for the failure was identified, the detector was repaired, the C-315 High Voltage PGLD system was tested and declared operable. The NRC Senior Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-09-2284 PGDP Event Report No. PAD-2009-15
After review, it was determined that a redundant operable PGLD detector was available to perform the intended safety function. Therefore according to 10CFR76.120, this event is not reportable. The NRC Resident Inspector has been notified of this retraction. Notified the R2DO (Rudisail) and NMSS (Waters). | ||
| ENS 45302 | 26 August 2009 02:40:00 | 10 CFR 76.120(c)(2) | Autoclave Pressure Relief System Inoperable | On 08-25-09, the Plant Shift Superintendent (PSS) was notified that C-360 (Toll Transfer & Sampling Building) Autoclave #4 had a failure in the autoclave pressure relief system. The autoclave pressure relief system utilizes a rupture disc in series with a relief valve. A pressure indicator is located between the rupture disc and the relief valve to verify that the pressure between the two devices is less than 5 psig per TSR 2.1.3.2 Condition A. This pressure is limited to prevent any significant bias to the actuation pressure of the rupture disc. TSR 2.1.3.2 requires that the actuation pressure of the autoclave pressure relief system shall not exceed 157.5 psig. On 08-25-09 at 2140 CDT, an operator was preparing to place the #4 autoclave into service, per the proper operating procedure, when the pressure between the rupture disc and the relief valve was found to be 5.5 psig, a pressure which indicated a failure in this required safety system. The autoclave was in a mode where this TSR system is required to be operable. There is low safety significance to this failure as the TSR does allow the current operating cycle to be completed under this condition. Since the operating cycle was just started and steam had not been applied to the autoclave, the operating evolution was abandoned and the autoclave was declared inoperable and taken out of service. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-09-2084; PGDP Event Report No. PAD-2009-12; Worksheet No. Responsible Division: Operations | ||
| ENS 44820 | 31 January 2009 07:50:00 | 10 CFR 76.120(c)(2) | Loss of Power to Criticality Accident Alarm System Horn | At 0150 CST, on 01-31-09 the Plant Shift Superintendent (PSS) was notified that a Criticality Accident Alarm System (CAAS) trouble alarm had actuated for the C-409 (Stabilization Building). The PSS dispatched personnel to investigate and discovered that a circuit breaker had tripped causing a loss of power to the CAAS horn uninterruptible power supply (UPS). Further investigation revealed that the output of the UPS was off. This caused loss of CAAS audibility for C-409 and TSR LCO 2.6.4.1b was immediately entered. There were no fissile material operations in progress and all personnel in the affected area had a radio in constant communication with the Central Communications Facility satisfying the required actions of TSR 2.6.4.1 b. The circuit breaker that tripped was closed, the UPS was turned back on, and TSR 2.6.4.1b was exited at 0317 hours. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-09-0203; PGDP Event Report No. PAD-2009-02 | ||
| ENS 44819 | 30 January 2009 18:17:00 | 10 CFR 76.120(c)(2) | 24 Hour Report of Process Gas Leak Detection System Inoperability | At 1217 CST, on 01-30-09 the Plant Shift Superintendent (PSS) was notified that C-310 (product withdrawal facility) had lost power due to an electrical fault. As a result of the power loss, the C-310 High Voltage Process Gas Leak Detection (PGLD) System was rendered inoperable. This PGLD System contains detectors that cover the C-310 UF6 condensers, accumulators, and piping heated housing. At the time of this loss of power, these areas were operating above atmospheric pressure. TSR 2.3.4.4 requires that all of detector heads in this system be operable during operations above atmospheric pressure. Power was restored to this PGLD System at 1240 hours, which is within the one hour required by TSR LCO 2.3.4.4.A.1 to enter a continuous smoke watch. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. Once the source of the fault was identified, power was restored to the C-310 the High Voltage PGLD System and the system was tested. Power was restored at 1240 hours and the system was tested at 1258 hours. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 44776 | 15 January 2009 02:39:00 | Other Unspec Reqmnt | Ongoing Recirculating Cooling Water Leak at C337A Facility | The site staffed their Emergency Operations Center to troubleshoot an ongoing recirculating cooling water leak under the concrete floor of the C337A autoclave facility. The process in that facility automatically shutdown and is in a stable condition. Overall impact to the plant is minimal and processes continue to operate in the cascade facility. Offsite assistance has been requested. DOE, Massac County, Illinois and McCracken and Ballard Counties in Kentucky have been notified. The licensee notified the NRC Resident Inspector.
The event was terminated at 0220. The leak is not isolated but has been localized. Notified the R2DO (Rudisail) and NMSS (Davis). | ||
| ENS 44744 | 28 December 2008 10:45:00 | Other Unspec Reqmnt | 24 Hour Report - Actuation of Leak Detection System Due to Minor Process Gas Leak | On 12/28/2008 at 0445 the C-337 unit 5 cell 3 PGLD (process gas leak detection) head located on stage 8 actuated. Operators responded to the alarm and performed sampling in the area. The sample result indicated 3 ppm of HF at the stage 8 compressor. To stop the release the cell was taken off-stream and the pressure was reduced to below atmosphere. Investigation indicated that a UF6 release had occurred. The amount of material released has not been determined. The actuated PGLD head is Q safety system component. At the time of the incident the cell was operating in a mode which required the system to be operable. This is being reported based on SAR 6.9 Table 1, J.2 as an Unplanned Actuation of a Q Safety System. The NRC Senior Resident Inspector has been notified of this event. The licensee states that a compressor seal appears to have failed. The amount of material released is characterized as on the order of a few grams. Material release was only in the vicinity of the compressor. There was nothing unusual or not understood and all systems functioned as required. There was no offsite release or personnel contamination resulted from this event.
A subsequent review by USEC Regulatory Affairs concluded that the UF6 Release Detection System detectors installed 'above the `B' seals on the axial flow compressors' (SAR 3.3.5.9.5), and the detectors for the instrument cubicles do not 'prevent or mitigate the consequences of postulated accidents that could result in a member of the general public located offsite being exposed to EG (Evaluation Guidelines)-1 or EG-2 guideline values' (SAR 4.2.2). Therefore, they do not meet the criteria to be classified as 'Q' (SAR 4.2.2). The safety equipment actuation reporting criteria (SAR 6.9-1 J.2) requires NRC to be notified of actuations of "Q" systems resulting from events that have the potential for significant impact on the health and safety of personnel, which are defined in the criteria as those events where actual plant conditions existed that the system was designed to protect against. Since the referenced UF6 Release Detection System detectors do not meet the criteria to be classified as "Q" and do not protect against a postulated accident that could result in a member of the general public being exposed to EG-1 or EG-2 guideline values, the actuations would not be reportable under this criteria. Summary: - the B-end seal PGLD (Process Head Leak Detector) head is not required to be 'Q' - the postulated release from the B-end seal cavity does not have significant impact on personnel. - A release from the B-end seal cavity is not a condition that the PGLD system is designed to protect against. The NRC Senior Resident Inspector has been notified of this event retraction. Notified R2DO (Rudisail) and NMSS (Kotzalas). | ||
| ENS 44742 | 27 December 2008 02:43:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection System Inoperable | At 2043 CST, on 12-26-08 the Plant Shift Superintendent (PSS) was notified that C-337 Unit 6 Cell 9 was above atmospheric pressure and the UF6 Release Detection (PGLD) System was inoperable. The cell had been running below atmosphere earlier in the day but a new gradient was put in and load movement caused pressure to go above atmosphere. The PGLD System for Unit 6 Cell 9 had been inoperable for an extended period of time due to wiring problems. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell are operable during steady state operations above atmospheric pressure. Even though the increase in cell pressure was due to load movement which is transient in nature, it was determined that the pressure had been above atmosphere for about four and a half hours, which is longer than the typical transient. With the Unit 6 Cell 9 PGLD system inoperable, none of the required cell heads were operable. TSR LCO 2.4.4.1.B.1 was entered and a continuous smoke watch was put in place within one hour. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event.
A subsequent review of the cell pressure proved that the cell pressures were below atmosphere at all times with the exception of one pressure spike of approximately 20 minutes. Since the cell was not operated above atmosphere and the TSR does not require PGLD systems to be operable during short term pressure transients, reporting under 10CFR76.120 is not required. Notified the R2DO (Lesser) and NMSS (Lorson). | ||
| ENS 44705 | 8 December 2008 08:19:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection System Inoperable | At 0219 CST, on 12-08-08 the Plant Shift Superintendent (PSS) was notified that the C-333 Unit 6 Cell 5 UF6 Release Detection (PGLD) System would not test fire during routine testing. Operators found that the READY, MANUAL, and POWER lights for this system were properly illuminated. This PGLD System contains detectors that cover only C-333 Unit 6 Cell 5 which was operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 5 PGLD system inoperable, none of the required cell heads were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 was entered and a continuous smoke watch was put in place within one hour. Engineering has determined, by analyzing the failed component, that the system would not have been able to perform its intended safety function when this condition was discovered. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. As of the time of the report, the problem has been corrected and the system returned to service. | ||
| ENS 44664 | 18 November 2008 09:08:00 | 10 CFR 76.120(c)(2) | Fire Water Sprinkler System Out of Service | At 0308 CST, on 11/18/2008, the Plant Shift Superintendent was notified that the C-337 High Pressure Fire Water (HPFW) Sprinkler System D-9 had been inspected by Fire Services and six sprinkler heads had visible corrosion on them. The system configuration was evaluated using EN-C-822-99-047, 'Effects of Impaired Sprinkler Heads on System Operability' and determined that with these heads impaired, a portion of the building would not have sufficient sprinkler coverage. The HPFW system is required to be operable according to TSR LCO 2.4.4.5. HPFW system D-9 was declared inoperable and TSR LCO 2.4.4.5 Required Action B was implemented for the area without sprinkler coverage. Based on past testing results, there is a possibility that the heads would have been able to perform their specified safety function. Once the heads are removed from the system, testing will be performed to determine the true affect on operability. This event is reportable under 10 CFR 76.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed. The NRC Senior Resident Inspector has been notified of this event. The site has implemented hourly fire patrols while this impairment is in affect.
The affected sprinkler heads were removed and subjected to testing in the plant laboratory. A total of nine heads (three of these heads were previously identified with corrosion) were removed and tested with five of the nine actuating as designed. Using these results, the plant's fire protection engineer concluded that adequate sprinkler coverage existed prior to the discovery and the system would have performed as designed to a fire demand. The licensee has notified the NRC Resident Inspector. Notified R2DO (Guthrie) and NMSS EO (Smith). | ||
| ENS 44621 | 1 November 2008 13:37:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection System Not Functioning Correctly | At 0837 CDT, on 11-01-08 the Plant Shift Superintendent (PSS) was notified that the Process Gas Leak Detection (PGLD) system for C-333 Unit 5 Cell 3 was not functioning as required. An operator was preparing to test fire the system as required by TSR SR 2.4.4.1-1 when it was discovered that the Ready light was not illuminated. This PGLD system contains detectors that cover C-333 Unit 5 Cell 3 and Section 1 and 2 of the cell bypass piping. At the time of this failure, Unit 5 Cell 3 and some areas of Sections 1 and 2 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 5 Cell 3 PGLD system inoperable, none of the required cell heads and only 2 of the required 3 heads in Sections 1 and 2 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 and 2.4.4.1.C.1 were entered and a continuous smoke watch was put in place within one hour. Engineering has determined that the system would not have been able to perform its intended safely function with the Ready light not illuminated. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR.08-3142; PGDP Event Report No. PAD-2008.034; | ||
| ENS 44608 | 28 October 2008 13:49:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection System Inoperable | At 0849 CDST, on 10-28-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-337 Unit 1 Cell 2 UF6 Release Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-337 Unit 1 Cell 2 and Section 1 of the cell bypass piping. At the time of this alarm, Unit 1 Cell 2 and some areas of Sections 1 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 1 Cell 2 PGLD system inoperable, none of the required cell heads and only 2 of the required 3 heads in Sections 1 of the cell bypass were operable. This PGLD System was declared inoperable. TSR LCO 2.4.4.1.A.1 and 2.4.4.1.C.1 were entered and a continuous smoke watch was put in place within one hour. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. This event is reportable as a 24 hour event in accordance with 10CFR76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. PGDP Event Report No. PAD-2008-033. The NRC Resident lnspector has been notified of this event. | ||
| ENS 44604 | 27 October 2008 07:39:00 | Other Unspec Reqmnt | Concurrent Notification to Nrc of Pcb Spill | At 1400, on 10/27/2008 CDT, the Plant Shift Superintendent was informed that EPA Region IV and the Kentucky Department of Environmental Protection had been notified of a PCB spill which occurred within the C-333 process building. This event is reportable as 'USEC shall notify NRC of any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. Such an event may include an on-site fatality or inadvertent release of radioactively contaminated materials.' The NRC Resident Inspector has been notified of this event. PGDP Problem Report No. ATRC�08�3077: PGDP Event Report No. PAD-2008-032 | ||
| ENS 44515 | 23 September 2008 14:37:00 | 10 CFR 76.120(c)(2) | Safety Equipment Failure Due to Loss of Power | At 0937 CDST, on 09/23/08 the Plant Shift Superintendent (PSS) was notified that C-315 (tails withdrawal facility) had lost power due to a fault on a 14 KV feeder. As a result of the power loss, the C-315 High Voltage Process Gas Leak Detection (PGLD) System was rendered inoperable. This PGLD System contains detectors that cover the C-315 UF6 condensers, accumulators, and piping heated housing. At the time of this loss of power, these areas were operating above atmospheric pressure. TSR 2.3.4.4 requires that all of detector heads in this system be operable during operations above atmospheric pressure. This PGLD System was declared inoperable. TSR LCO 2.3.4.4.A.1 was entered and a continuous smoke watch was put in place within one hour. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand; and, c.) no redundant equipment is available and operable to perform the required safety function. Once the source of the fault was identified, power was restored to the C-315 facility. The High Voltage PGLD system was tested, and the system was declared operable. Power was restored at 1039 hours and the High Voltage PGLD System was declared operable at 1118 hours. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-08-2371; PGDP Event Report No. PAD-2008-29; Responsible Division: Operations. | ||
| ENS 44448 | 28 August 2008 16:43:00 | 10 CFR 76.120(c)(2) Other Unspec Reqmnt | Leak in High Pressure Fire Water System | At 1143, on 8/28/08, the Plant Shift Superintendent was notified of a large water leak on High Pressure Fire Water system (HPFW) A-12 in building C-333 due to a piping rupture. The HPFW system provides water for fire suppression to the plant's process buildings. A-12 is 1 of 66 HPFW systems in this process building. Leak analysis indicates the HPFW system A-12 would not have been able to perform its intended safety function while the leak was occurring. The leak was determined to be between the process building and the post indicating valve (PIV). The PIV for this system was closed which isolated the leak. Required TSR LCO actions have been and are being performed. This is being reported as an event in which equipment is disabled or fails to function as designed when the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and no redundant equipment is available. The NRC Senior Resident Inspector has been notified of this event.
On 8/29/08, the Kentucky Department of Water (KDOW) was notified that approximately 30,000 gallons of recirculating water (RCW) from the HPFW system containing 4 ppm phosphorus residual was discharged through Outfall 9. RCW discharge to Outfall 9 is reportable to KDOW as a bypass of a treatment system that causes an exceedance of a permit limit per 401 KAR 5:065 Section 1(12)(f). The NRC Senior Resident Inspector has been notified of this event. Notified R2DO (Nease) and NMSS EO (Mamish). | ||
| ENS 44356 | 20 July 2008 17:20:00 | 10 CFR 76.120(c)(2) | Failure of Process Gas Leak Detection System | At 1230 CDST, on 07-20-08 the Plant Shift Superintendent (PSS) was notified that C-315 had received an audible alarm with no visual indications. Moments later an alarm was received in C-331 for the C-315 High Voltage Process Gas Leak Detection System. Operators responded by contacting C-315 to inquire about the alarm. C-315 operators checked the system and found that the READY light for this system was not illuminated. This PGLD System contains detectors that cover the C-315 UF6 condensers, accumulators, and piping heated housing. At the time of this alarm, the areas were operating above atmospheric pressure. TSR 2.3.4.4 requires that all of detector heads in this system be operable during operations above atmospheric pressure. Operators responding to the system tried to test fire the system heads however the system would not respond and then they discovered the READY light to be off. This PGLD System was declared inoperable, TSR LCO 2.3.4.4.A.1 was entered and a continuous smoke watch was put in place within one hour. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. This event is reportable as a 24 hour event in accordance with 10CFR 76.120 (c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. | ||
| ENS 44310 | 21 June 2008 04:25:00 | Other Unspec Reqmnt Part 70 App A (C) | Notification to Kentucky Ert Due to Exceeding Permit Limits at Outfall | At 1750, 6/21/2008 CDT, the Kentucky Emergency Response Team (Report Number 2008-2125) was notified of the following issue. The C-637 RCW (Recirculating Water) 'H' Supply loop was being repaired and a residual RCW leak from the valve vault was being pumped back to the pump house basin when the portable pump shutdown causing an overflow condition at a Commonwealth of Kentucky permitted outfall 002. The Commonwealth of Kentucky's permit limit for the outfall is 1 mg/L for total phosphorus and the chlorine level is to be below detectable limits. Contrary to this, the total phosphorus level was slightly above 1 mg/L and residual chlorine was approximately 0.1to 0.3 mg/L. Control of the RCW leak in the valve vault was re-established. This event is reportable as 'USEC shall notify NRC of any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. Such an event may include an on-site fatality or inadvertent release of radioactively contaminated materials.' The NRC Resident Inspector has been notified of this event. PGDP Problem Report No. ATRC-08-1840: PGDP Event Report No. PAD-2008-20: | ||
| ENS 44202 | 12 May 2008 17:30:00 | 10 CFR 76.120(c)(2) | 24-Hr Report - Uf6 Release Detection System Failure | At 1230 CDST, on 05-12-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-331 Unit 3 Cell 5 UF6 Release Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-331 Unit 3 Cell 5 and Sections 2 and 3 of the cell bypass piping. At the time of this alarm, unit 3 Cell 5 and some areas of Sections 2 and 3 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 3 Cell 5 PGLD system inoperable, none of the required cell heads and only 2 of the required 3 heads in Sections 2 and 3 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.A.1 and 2.4.4.1.C.1 were entered and a continuous smoke watch was put in place within one hour. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-08-1412; PGDP Event Report No. PAD-2008-14; Worksheet No. Responsible Division: Operations | ||
| ENS 44158 | 22 April 2008 14:00:00 | 10 CFR 76.120(c)(2) | Improperly Installed Steel Angle Supports on Freezer Sublimer Vessel | At 0900 CDT on 04-22-08, the Plant Shift Superintendent (PSS) was notified that the weight monitoring systems on vessels 2 on C-333 Unit 1 Cell 9, Unit 2 Cell 2, Unit 4 Cell 2 and Unit 4 Cell 9 freezer-sublimers showed weight changes when improperly installed steel angle supports welded to the vessel inlet piping were cut free. Each freezer sublimer vessel has a weight monitoring and trip system (high-high weight trip system) that prevents the over-filling of UF6 into the vessel. The high-high weight trip system is required by TSR 2.4.3.1 to prevent overfilling the freezer-sublimer vessels when in mode F/S 1 (freeze) or F/S 3 (cold standby). At the time of discovery, each freezer sublimer was in a non-applicable TSR mode F/S 6 (out-of-service). However, each freezer-sublimer has been routinely operated in TSR modes F/S 1 and F/S 3 over several years with the steel angle supports installed. The steel angle supports were likely installed to facilitate piping alignment during freezer-sublimer construction over fifteen years ago. The steel angle supports were not removed after construction. The presence of the steel angle supports may affect the performance the high-high weight trip system specified in TSR 2.4.3.1. All other installed freezer-sublimers were inspected and no additional steel angle supports were similarly connected. Engineering personnel are conducting a formal stress analysis to determine the stresses the steel supports may have had on the weight monitoring and trip system. There is no evidence that the weight limits specified in TSR 2.4.3.1 have been exceeded as a result of this issue. Pending further analysis, this event is conservatively being reported as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. PGDP Assessment and Tracking Report No. ATRC-08-l 183; PGDP Event Report No. PAD-2008-12; Worksheet No. 44158 The NRC Senior Resident Inspector has been notified of this event.
Retracted on 5/29/08, engineering calculations show that the error from the supports was less than the margin provided in the setpoint calculations. The licensee notified the NRC Resident Inspector. Notified the R2DO (Widman) and NMSS (Stablein). | ||
| ENS 44134 | 11 April 2008 00:03:00 | 10 CFR 76.120(c)(2) | Failed Detector Heads | At 1903 CST, on 04-10-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received in the C-335 Area Control Room for the C-335 Unit 2 Cell 7 UF6 Release Detection (PGLD) System. Operators responded to the local panel and found all detector heads in alarm. Operators attempted to reset the system and the system would not reset, all heads remained in alarm. Operators then responded to the Unit 2 Cell 7 cell floor with the proper PPE and confirmed there was not a UF6 release. This PGLD System contains detectors that cover the C-335 Unit 2 Cell 7 cell housing roof and cell exhaust duct and sections 3 & 4 of the cell bypass housing. At the time of this alarm, C-335 Unit 2 Cell 7 and sections 3 & 4 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell housing roof, cell exhaust duct, and cell bypass housing are operable during steady state operations above atmospheric pressure. With all the Unit 2 Cell 7 PGLD system heads locked in alarm, none of the required 3 heads in the cell housing roof and cell exhaust duct were operable and less of the required 3 heads in the cell bypass housing sections were operable. This PGLD System was declared inoperable, TSR LCOs 2.4.4.1.A.1 and 2.4.4.1.C.1 were entered and a continuous smoke watch was put in place within one hour. An investigation is ongoing to attempt to determine the cause of the failure. This event is being reported as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATRC-08-1089; PGDP Event Report No. PAD-2008-10; Worksheet No. 44134 Responsible Division: Operations
The update is a retraction. Investigation has attributed the false alarm to a moisture problem and not a loss of power. The system did not fail. The licensee notified the NRC Resident Inspector. Notified R2 (Robert Haag) and NMSS (Jack Guttmann) | ||
| ENS 43987 | 14 February 2008 08:07:00 | 10 CFR 76.120(c)(2) | Alarm Received from Uf6 Release Detection System | At 0207 CST, on 02-14-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received in the C-333 Area Control Room for the C-333 Unit 5 Cell 8 UF6 Release Detection (PGLD) System. Operators responded to the local panel and verified the alarm was not due to a UF6 release, but local panel lights were flickering. Operators attempted to test the system and the system would not test fire. This PGLD System contains detectors that cover the C-333 Unit 5 Cell 8 cell housing roof and inter-cell housing and section 4 of the cell bypass housing. At the time of this alarm, C-333 Unit 5 Cell 8 and section 4 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell housing roof, inter-cell housing, and section 4 of the cell bypass housing are operable during steady state operations above atmospheric pressure. With the Unit 5 Cell 8 PGLD System inoperable, none of the required 3 heads in the cell housing roof and inter-cell housing were operable and only two of the required 3 heads in the cell bypass housing were operable. This PGLD System was declared inoperable. TSR LCOs 2.4.4.1.B.1 and 2.4.4.1 .C.1 were entered and a continuous smoke watch was put in place within one hour. An investigation is ongoing to attempt to determine the cause of the failure. This event is being reported as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 43953 | 31 January 2008 20:06:00 | 10 CFR 76.120(c)(2) | 24 Hour Report of Release Detection System Failure | At 1406 CST, on 01-31-08 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333 Unit 3 Cell 5 UF6 Release Detection (PGLD) System. Operators responded to the panel and verified the alarm was false but when they attempted to test the system it failed. Preliminary troubleshooting indicates that the cause of the alarm may have been a momentary loss of power. This PGLD System contains detectors that cover the C-333 Unit 3 Cell 5 cell housing roof and inter-cell housing. At the time of this alarm, C-333 Unit 3 Cell 5 was operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell housing roof and inter-cell housing are operable during steady state operations above atmospheric pressure. With the Unit 3 Cell 5 PGLD system inoperable, none of the required 3 heads in the cell housing roof and inter-cell housing were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 was entered and a continuous smoke watch was put in place within one hour. An investigation is ongoing to attempt to conclusively and accurately determine the cause of the alarm. This event is being reported as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 43903 | 13 January 2008 21:12:00 | 10 CFR 76.120(c)(2) | Failure of Uf6 Release Detection System | At 1512 CST, on 01-13-08 the Plant Shift Superintendent (PSS) was notified that the C-333 Unit 6 Cell 7 UF6 Release Detection (PGLD) System failed to function when performing the twice per shift test firing. Test firing of the PGLD detector heads is required per TSR SR 2.4.4.1-1. TSR 2.4.4.1 also requires that at least the minimum number (three) of detector heads in the cell and in each defined section of the cell bypass are operable where UF6 systems are above atmospheric pressure. The C-333 Unit 6 Cell 7 PGLD System contains detectors that covers the cell and Sections 3 and 4 of the cell bypass piping. At the time of this failure some areas of Section 3 of the cell bypass were operating above atmospheric pressure. Since Unit 6 Cell 7 was operating below atmosphere, the cell was not in an applicable TSR mode. However, Section 3 of the cell bypass was above atmosphere and in an applicable TSR mode which required at least three operable PGLD heads. With the Unit 6 Cell 7 PGLD system inoperable only two of the required three heads in Section 3 of the cell bypass were operable. This PGLD System was declared inoperable, and system pressure in the affected operating area was reduced to less than atmospheric pressure within one hour, thus placing the operating system in a non-applicable TSR mode. This event is being reported as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-08-0122; PGDP Event Report No. PAD-2008-01; Worksheet No. 43903 Responsible Division: Operations The licensee is investigating the cause of the event, and will make appropriate notifications to the Department of Energy.
On January 13, 2008 the C-333 U/6 C/7 PGLD system failed during testing. This affected all the PGLD heads in the cell area and two of the four heads in section 3 of the cell by-pass. A review of operating pressures in the affected area determined that the cell was operating below atmospheric pressure, but that piping in section 3 of the cell by-pass was operating above atmosphere. Thus, three of four heads in section 3 of the Cell by-pass were required by the TSR to be operable. Given the recent failure in November and indications that the failure modes may be similar, the PSS reported the event to the NRC per 10CFR 76.120(c)(2)(i), In-Service Safety System Failure. Subsequent to the event, the pressures in C-333 U/6 CR, section 3 in the cell by-pass area associated with the event were reviewed. Using Engineering Notice EN-C-821-05-090, Rev, 3, it was determined that section 3 of the cell by-pass was actually not operating above atmosphere and thus, the PGLD system was not required to be operable at the time of the failure. Since the failure only affected detectors in an area operating in a non-TSR mode, the PGLD system is not required to be operable and reporting under 10 CFR 76.120(C)(2) is not required. The licensee notified the NRC Resident Inspector. The licensee made appropriate notifications to the Department of Energy. R2DO (Moorman) and NMSS EO (Kokajko) notified. | ||
| ENS 43864 | 23 December 2007 09:58:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Small Uf6 Process Leak | On 12/23/2007 at 0358 the C-333 unit 3 cell 1 PGLD (process gas leak detection) head (YE-5) at stage 5 actuated. Along with the PGLD actuation a seal alarm and a vibration alarm on stage 7 were received. A nearby operator on the cell floor responded to the alarm and observed a small UF6 release from the stage 7A seal cavity. To stop the release the cell was immediately shut down from the ACR which lowered the cell's pressure to below atmospheric pressure. The exact amount of material released has not been determined. Checks by health physics personnel found the actual amount of UF6 released was not significant and resulted in a relatively small area of contamination on the end of the compressor near the seal that failed and on the floor immediately around the end of the compressor. The actuated PGLD head is a Q safety system component. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120(c)(1)(i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. PGLD Problem Report Nos. ATRC-07-3433; PGLD Event Report No. PAD-2007-022; NRC Event Number 43864 | ||
| ENS 43829 | 7 December 2007 02:44:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Unplanned Safety System Actuation and Contamination Event | On 12/06/2007 at 2042 (CST) C-337 unit 5 cell 5 was being charged and placed on stream and had just gone above atmospheric pressure. At 2044 hours two PGLD (process gas leak detection) heads in the C-337 unit 5 cell 5 actuated and would not clear indicating a potential UF6 release. To stop the release the cell was immediately taken back below atmospheric pressure. Investigation revealed that a UF6 release had occurred causing the PGLD actuation. The amount of material released has not yet been determined. The PGLD heads are Q safety system components. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120 (c) (1) (i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. There was no release to the environment and no personnel contaminations reported. | ||
| ENS 43828 | 6 December 2007 21:50:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Unplanned Safety System Actuation and Contamination Event | On 12/06/2007 at 1550 (CST) the C-337 unit 5 cell 3 PGLD (process gas leak detection) head in the C-337 unit 5 cell 3 housing actuated and would not clear. Response to the alarm by operators revealed a haze above the cell indicating a UF6 release inside the cell housing. While the operators were responding to the unit 5 Cell 3 alarm, two other PGLD heads actuated in C-337 unit 5 cell 5. To stop the release both cells 3 and 5 were taken below atmospheric pressure. Investigation indicated that a UF6 release had occurred. The amount of material released has not been determined. The actuated PGLD heads are Q safety system components. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120 (c) (1) (i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. There was no release to the environment and no personnel contaminations reported. | ||
| ENS 43801 | 21 November 2007 02:28:00 | 10 CFR 76.120(c)(2) | Failure of Uf6 Release Detection System | At 2028 CDST, on 11-20-07 the Plant Shift Superintendent (PSS) was notified that the C-333 Unit 6 Cell 7 UF6 Release Detection (PGLD) System failed to function when performing the twice per shift test firing. The test firing of the PGLD detector heads is required per TSR-SR 2.4.4.1-1. This PGLD System contains detectors that cover C-333 Unit 6 Cell 7, Section 3, and Section 4 of the cell bypass piping. At the time of this failure, unit 6 cell 7 and some areas of Section 3 and Section 4 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in the cell and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 7 PGLD system inoperable, none of the required cell heads and only 2 of the required 3 heads in Section 3 and Section 4 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.B.1 and 2.4.4.1.C.1 was entered and a continuous smoke watch was put in place within one hour. Troubleshooting indicated the failure was not similar to writing failures recently experienced on other PGLD systems. The two components most susceptible to failure have been replaced and investigations continue into root cause. The system had functioned correctly when the previous test firing was performed at 1430 hours on 11-20-07. However, since the failure potentially occurred prior to the test firing at 2028 hours the event is being reported as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when (a) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; (b) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and (c) no redundant equipment is available and operable to perform the required safety function." The NRC Resident Inspector has been notified of this event. | ||
| ENS 43787 | 15 November 2007 15:15:00 | Other Unspec Reqmnt | Safety System Actuation Due to Incidental Uf6 Release | On 11/15/2007 at 0915 instrument mechanics were performing a cell datum calibration in the C-333 Unit 4 Cell 2 cell panel when a strong odor assumed to be HF was noticed after the stage 1 high side pressure valve was opened. The 1/4" valve is on a manifold which accesses pressure taps in various locations in the cell. When the odor was detected a UF6 leak detection head located in the cell panel ducting also actuated. The mechanic opening the valve, immediately closed the valve when the odor was detected and they immediately left the area. HF samples taken a few minutes later in the area around the cell panel were all negative. Precautionary urine samples have been taken from the individuals involved and analysis are being run on the samples. It is believed a small incidental UF6 release occurred when the small high side valve was momentarily opened and actuated the UF6 detection system head which is a Q safety system component. At the time of the incident the cell was in operation in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2. The NRC Resident Inspector has been notified of this event. | ||
| ENS 43708 | 9 October 2007 22:00:00 | 10 CFR 76.120(c)(2) | Safety System Valve Did Not Operate as Expected | At 1700 CDT, on 10-09-07 the Plant Shift Superintendent (PSS) was notified that the C-333 Unit 4 Cell 3 freezer/sublimer computer indicated that the 'B' valve failed to unknown status. Investigation by an operator determined that the 'B' valve would not operate electrically and was in the open position. The freezer/sublimer automatically transitioned to the Hot Standby Mode (FS4) and the electrically failed 'B' valve was closed manually by an operator. The freezer/sublimer was being operated in mode FS1, the freeze mode, at the time of the failure. TSR 2.4.3.1 requires the high-high weight trip system and its associated 'B' valve to be operable in mode FS1. It was determined that the system would not have been able to perform its intended safety function with the 'B' valve disabled. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-07-2675; PGDP Event Report No. PAD-2007-16 | ||
| ENS 43696 | 5 October 2007 21:43:00 | 10 CFR 76.120(c)(2) | Process Gas Leak Detection (Pgld) System Inoperable | At 1643 CDST, on 10-05-07 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333 Unit 6 Cell 8 UF6 (Process Gas Leak) Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-333 Unit 6 Cell 8 and Section 4 of the cell bypass piping. At the time of this alarm, unit 6 cell 8 and some areas of Section 4 of the cell bypass were operating above atmospheric pressure." Electricians are currently troubleshooting to determine the source of the potential short circuit that caused the problem. (Technical Safety Requirement) (TSR) 2.4.4.1 requires that at least the minimum number of detector heads in the cell and in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 8 PGLD system inoperable, none of the required cell heads and only 2 of the required 3 heads in Section 4 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.C.1 was entered and a continuous smoke watch was put in place within one hour. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a. The equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b. the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand; and c. no redundant equipment is available and operable to perform the required safety function. The NRC Resident Inspector has been notified of this event. PGDP Assessment and Tracking Report No. ATR-07-2655; PGDP Event Report No. PAD-2007-15; Responsible Division: Operations. | ||
| ENS 43686 | 2 October 2007 19:06:00 | 10 CFR 76.120(c)(2) | Release Detection System (Pgld) Declared Inoperable | At 1406 CDST, on 10-02-07 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333, Unit 6, Cell 4, UF6 Release Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-333, Unit 6, Cell 4, and Section 2 of the cell bypass piping. At the time of this alarm, some areas of Section 2 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 6, Cell 4, PGLD System inoperable, only 2 of the required 3 heads in Section 2 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1 .C.1 was entered and a continuous smoke watch was put in place within one hour. An investigation is ongoing and at this point a wire was found that had failed with visible insulation damage. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. This event is reportable as a 24 hour event in accordance with 10 CFR 76.1 20(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand, and c.) no redundant equipment is available and operable to perform the required safety function. This event is similar to EN#43670 on 09/27/07. The NRC Senior Resident Inspector has been notified of this event. | ||
| ENS 43670 | 27 September 2007 05:12:00 | 10 CFR 76.120(c)(2) | Temporary Loss of Smoke Detector Function | At 0012 CDST, on 9-27-07 the Plant Shift Superintendent (PSS) was notified that an alarm was received for the C-333 Unit 6 Cell 4 UF6 Release Detection (PGLD) System. Operators responded and found that the READY and MANUAL lights for this system were not illuminated. This PGLD System contains detectors that cover C-333 Unit 6 Cell 4 and Section 2 of the cell bypass piping. At the time of this alarm, some areas of Section 2 of the cell bypass were operating above atmospheric pressure. TSR 2.4.4.1 requires that at least the minimum number of detector heads in each defined section of the cell bypass are operable during steady state operations above atmospheric pressure. With the Unit 6 Cell 4 PGLD system inoperable, only 2 of the required 3 heads in Section 2 of the cell bypass were operable. This PGLD System was declared inoperable, TSR LCO 2.4.4.1.C.1 was entered and a continuous smoke watch was put in place within one hour. Maintenance investigated and determined that two detector heads had shorted to ground which caused this alarm. Engineering has determined that the system would not have been able to perform its intended safety function when this alarm came in. The shorted heads were replaced and the GLD System was declared operable at 0350 hours on 9-27-07 following repairs and testing. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated o demand, and c.) no redundant equipment is available and operable to perform the required safety function. The licensee notified the NRC Resident Inspector. |