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	Start date	Reporting criterion	Title	Event description
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. * * RETRACTION FROM DEREK WARFORD TO VINCE KLCO AT 1932 EDT ON 5/16/2014 * * * 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. * RETRACTION ON 3/28/14 AT 1959 EDT FROM JOE BARLETTO TO DONG PARK * * 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 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 * * RETRACTION FROM BILLY WALLACE TO JOHN SHOEMAKER AT 1641 EDT ON 07/16/2012 * * * 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 * * UPDATE FROM BILLY WALLACE TO DONALD NORWOOD AT 1640 EDT ON 5/9/2012 * * * 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). * * RETRACTION FROM DAVID PETTY TO DONG PARK AT 1403 EDT ON 5/15/2012 * * * 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 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. * * RETRACTION FROM BILLY WALLACE TO JOE O'HARA AT 1145 EDT ON 5/20/11 * * * 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 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 * * UPDATE FROM JOE BARLETTO TO HOWIE CROUCH @ 2254 EDT ON 5/1/10 * * * 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. * * UPDATE FROM ROD COOK TO JOHN KNOKE @ 1737 EDT ON 5/2/10 * * * 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 * * RETRACTION FROM DERRICK WARFORD TO DONG PARK ON 9/23/2009 AT 1553 EDT * * * 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 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. * * RETRACTION ON 12/31/2008 AT 1716 FROM TONY HUDSON TO MARK ABRAMOVITZ * * * 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. * * RETRACTION FROM TONY HUDSON TO HOWIE CROUCH @1536 EST ON 11/21/08 * * * 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 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. * * UPDATE PROVIDED BY ROD COOK TO JASON KOZAL ON 8/29/08 AT 1611 * * * 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 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. * * RETRACTION ON 5/29/2008 AT 1815 FROM BILLY WALLACE TO MARK ABRAMOVITZ * * * 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 * * UPDATE FROM B. WALLACE TO J. KNOKE AT 1021 EDT ON 6/4/08 * * * 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. * * RETRACTION PROVIDED BY TONY HUDSON TO JASON KOZAL AT 1403 ON 1/18/08 * * * 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 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 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.
ENS 43312	22 April 2007 08:20:00	10 CFR 76.120(c)(2)	Uf6 Release Detection System Inoperable	At 0320 CDST, on 4-22-07 the Plant Shift Superintendent (PSS) was notified that the control power for C-337A #1 Autoclave had been lost due to a blown control power fuse. Investigation of a problem with the Autoclave 1 West CV-510 valve close indicating light not functioning properly was in progress at the time the fuse blew. Maintenance personnel were performing non-intrusive checks of the valve's limit switch and had activated the limit switch operating plunger when the fuse blew. No maintenance work package was used for these checks. The power supply for the local autoclave area audible and visible alarms for the UF6 Release Detection System are fed from the #1 Autoclave control power. Due to this loss of control power, the UF6 Release Detection System was rendered inoperable. At the time of the incident, the C-337A facility was operating in an operational mode in which the UF6 Release Detection System was required to be operable, TSR 2.2.4.1 Mode 5. The C-337A Operations Monitoring Room where UF6 Release Detection System alarms would have been received was unoccupied at the time of the fuse failure due to C-337A personnel in the autoclave area assisting with the CV-510 light investigation. The system was declared inoperable and Limiting Conditions of Operation (LCO) required action, TSR 2.2.4.1 A.1, was put in place until power could be restored. Subsequent troubleshooting revealed the CV-510 limit switch was broken and has shorted the control circuit to ground when activated causing the fuse to blow. Power was restored and the UF6 Release Detection System was declared operable at 0539 on 4-22-07 following repairs and PMT. The event is reportable as a 24 hour event as required by 10 CFR 76.120(c)(2)(i); An event in which equipment is disabled or fails to function as designed when the equipment is required by TSR to be available and operable and no redundant equipment was available to perform the required safety function. The NRC Senior Resident Inspector has been notified of this event.
ENS 43305	17 April 2007 00:15:00	10 CFR 76.120(c)(2)	Large Water Leak on High Pressure Fire Water System	At 1915, on 04/16/07, the Plant Shift Superintendent was notified of a large water leak on High Pressure Fire Water system. This system provides water for fire suppression to the plants process buildings. An alarm was received indicating a drop in the level of High Pressure Fire Water (HPFW) elevated tank. The buildings were contacted to look for a large water leak and the leak was quickly located inside the C-337 process building. The exact system leaking was not apparent as the leak was under the building concrete floor. To stop the leak the HPFW pumps supporting the system were shutdown and the sectional valves outside the building were closed. This action made the HPFW system for all process buildings inoperable. LCO actions 2.4.4.8 and 2.4.4.6 were entered. The leak was determined to be on C-337 system C-12 and this system and the two adjacent systems were isolated and all other previously isolated valves were reopened. The HPFW pumps were restarted and the HPFW elevated tank was refilled to the TSR required level. These actions restored HPFW operability to the other areas in the plant at 2101 hours. TSR required hourly fire patrols were initiated for the affected area in C-337. The leak is located on an underground eight inch header under the alarm and actuation controls for system C-12 inside the building. This is being reported as an event in which equipment is disabled or fail 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 licensee stated that this leak caused substantial damage to the concrete pad on the floor of the building. No structural damage is believe to have occurred but the concrete pad with have to be completely removed, the piping repaired, and eroded earth backfilled. A new concrete pad will then likely need to be poured. Nearly half a million gallons of water may have been lost through the break before it was isolated. The licensee has checked the site outfalls and no contamination was detected. The licensee notified the NRC Resident Inspector.
ENS 43268	30 March 2007 15:30:00	10 CFR 76.120(c)(2)	Safety Equipment Failure - Process Gas Leak Detection System	At 1030, on 3-30-07 the Plant Shift Superintendent was notified of the failure of the C-333A Process Gas Leak Detection (PGLD) detector head YE-613-21. Detector head YE-613-21 is located in the piping trench between the autoclaves. The trench detector heads are scheduled to be replaced at a six month interval. Operators were performing an "as-found" test on the head prior to scheduled replacement. The detector head did not alarm as required when smoke was applied during the test. The Process Gas Leak Detection system is required to be operable according to TSR 2.2.4.1. This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(l). 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 YE-613-21 detector head was replaced approximately 6 months ago and was last known to be functional approximately one month ago after some wiring tests were conducted in the area of the detector head. The permittee is conducting failure cause analysis to determine failure mode and possibly identify when failure occurred. The NRC Senior Resident Inspector has been notified of this event. PGDP Problem Report No. ATRC-07-0819; PGDP Event Report No. PAD-2007-02
ENS 42973	7 November 2006 22:07:00	10 CFR 76.120(c)(2)	Failure of Process Gas Leak Detection System	At 1607 on 11/7/2006, the Plant Shift Superintendent (PSS) was notified of a failure of the C-333 Unit 6 Cell 3 process gas leak detection (PGLD) system. C-333 operators were alerted to the Unit 6 Cell 3 PGLD failure by the receipt of an Area Control Room alarm. The operators responded to the Unit 6 Cell 3 cell panel and discovered that the PGLD system was inoperable. C-333 Unit 6 Cell 3 and associated piping were operating above atmospheric pressure (Cascade Mode 2) at the time of the PGLD failure. The operators initiated a continuous smoke watch of the area with lost PGLD coverage until the associated equipment and piping pressure was reduced below atmospheric pressure in accordance with TSR LCO 2.4.4.1. The PGLD system is required per TSR 2.4.4.1 to be operable when a cascade cell and associated piping is above atmospheric pressure (Cascade Mode 2). 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 Problem Report No. ATRC-06-3679; PGDP Event Report No. PAD-2006-11; NRC Worksheet No. 42973. The licensee stated that the equipment and piping pressure was reduced in order to allow the process to continue operating in a condition where the PGLD system is not required to be operable. The licensee is investigating the cause of the failure but it is preliminarily believed to be a failure of an instrumentation power supply.
ENS 42972	7 November 2006 14:59:00	10 CFR 76.120(c)(2)	Process Gas Leak Detector Failure	At 0859 on 11/7/2006, the Plant Shift Superintendent (PSS) was notified of a failure of the C-337A process gas leak detector (PGLD) YE-613-21 to alarm during TSR (Technical Safety Requirements) surveillance 2.2.4.1-1. TSR surveillance 2.2.4.1-1 is a quarterly test to verify that the PGLD will detect a UF6 release, alarm, and alert personnel. PGLD YE-613-21 provides coverage for the north section of the facility UF6 piping trench. Staff review of the failure, suggest that PGLD YE-613-21 may have failed prior to being removed from service to perform the 11/7/06 TSR surveillance. PGLD YE-613-21 was replaced and tested satisfactorily. Additional testing and engineering review of PGLD YE-613-21 is being performed to ensure the operability of the PGLD and to develop any needed corrective actions. 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 Problem Report No. ATRC-06-3670; PGDP Event Report No. PAD-2006-10; NRC Worksheet No. 42972.
ENS 42866	28 September 2006 23:02:00	10 CFR 76.120(c)(2)	Failure of Autoclave High Cylinder Pressure System	At 1802 CDT on 09/28/06, the Plant Shift-Superintendent (PSS) was notified of a failure of the C-333A Autoclave 3 South High Cylinder Pressure System (HCPS). During a normal cylinder heating cycle the operator noted that the cylinder pressure, as read on a local digital pressure indicator and on a digital recorder in the Operations Monitoring Room (OMR), unexpectedly fell from a steady 65 psia to a negative value on both instruments. A 14 ton cylinder containing 0.4019% U235 assay uranium hexafluoride had been heating (TSR Mode 5) for approximately 2.2 hours when the failure occurred. The PSS declared the HCPS inoperable and TSR LCO 2.2.4.14B actions were implemented to place the autoclave in Mode 2, 'Autoclave Open and Out-of-Service'. The HCPS is a TSR system designed to minimize the potential of primary system integrity failure (cylinder rupture) during a pressure increase event by tripping the steam supply to the autoclave prior to reaching the Maximum Allowable Working Pressure (MAWP) of the cylinder. 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. There was no release of radioactive material. The licensee notified the NRC Resident Inspector.
ENS 42763	10 August 2006 22:05:00	10 CFR 76.120(c)(2)	Inoperable High Pressure Fire Water System	At 1705, on 08-10-06, the Plant Shift Superintendent was notified of a large water leak on High Pressure Fire Water system A-5. This system provides water for fire suppression to a portion of the C-337 process building. The system was immediately isolated and TSR (2445) required hourly fire patrols were initiated for the affected area. The leak was located on an underground eight inch header immediately adjacent to the south wall of the building. Engineering has reviewed this incident and determined that due to the size of the leak, the system could not have performed the intended safety function. 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. PGDP Problem Report No. ATRC -06-2592; PGDP Event Report No. PAD-2006-07; Worksheet No. Responsible Division: Operations. The NRC Senior Resident Inspector has been notified of this event.
ENS 42590	20 May 2006 12:15:00	10 CFR 76.120(c)(2)	High Pressure Transmitter Failure	At 0715 CDT on 05120/06, the Plant Shift Superintendent (PSS) was notified of a failure of the C-333A Autoclave 2 North High Cylinder Pressure System (HCPS). During a normal cylinder heating cycle the operator noted that the cylinder pressure, as read on a local digital pressure Indicator and on a digital recorder in the Operations Monitoring Room (OMR), unexpectedly fell from 55 psia to a negative value on both instruments. A 14 ton cylinder containing (deleted) U235 assay uranium hexafluoride had been heating (TSR Mode 5) for approximately 8 hours when the failure occurred. The PSS declared the HCPS inoperable and TSR LCO 2.2.4.14B actions were implemented to place the autoclave in Mode 2, 'Autoclave Open and Out-of-Service'. The HCPS is a TSR system designed to minimize the potential of primary system integrity failure (cylinder rupture) during a pressure increase event by tripping the steam supply to the autoclave prior to reaching the Maximum Allowable Working Pressure (MAWP) of the cylinder. 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. Work Request #5087574" submitted to troubleshoot and repair. PGDP Problem Report No. ATRC-06-1655; PGDP Event Report No. PAD-2006-06; NRC Worksheet No. 42,590 The NRC Senior Resident Inspector has been notified of this event.
ENS 42494	12 April 2006 13:13:00	10 CFR 76.120(c)(2)	Uf6 Release Detection System Failed During Testing	At 0813 CDT on 04/12/2006, the Plant Shift Superintendent (PSS) was notified that immediately following routine test firing of the C-333 Unit 4 cell 7 UF6 Release Detection System (TSR surveillance requirement 2.4.4.1-1), smoke and sparks were observed coming from the UF6 Release Detection System control module and the system ready light was extinguished. The Area Control Room alarm locked in and the system was declared inoperable by the PSS. The cell and associated piping were above atmospheric pressure (Cascade Mode 2) at the time of the failure. The UF6 Release Detection System is a TSR system that is required to be operable per TSR 2.4.4.1, when a cascade cell and associated piping are in Cascade Mode 2. After discovery of failed system condition, a continuous UF6 smoke watch was initiated on the areas affected by the loss of detection capability in accordance with LCO Required Actions 2.4.4.1.B.1 and 2.4.4.C.1. 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 Problem Report No. ATRC-06-1197; PGDP Event Report No. PAD-2006-03. There was no release from this event. The failure was shorted contacts in the alarm reset relay. * * UPDATE FROM WALLACE TO KNOKE AT 19:04 EDT on 04/18/06 * * * This report is being retracted. Subsequent to the event, Maintenance and System Engineering determined that the alarm disable switch control module faulted when the operator attempted to reset the ACR PGLD alarm. This fault caused the system power supply to fail. Resetting the alarms is the last step in the test procedure being performed when the failure occurred. Only after the alarms are cleared is the PGLD system returned to normal operating condition and testing complete. In this case, the evidence clearly indicated that the failure occurred during the conduct of the surveillance and the successful firing of the detectors and the start of the test provides positive evidence that the failure did not exist prior to the surveillance. Therefore, the in-service safety system failure reporting criteria of 10CFR 76.120(c)(2)(i) is not applicable. The Senior Resident Inspector has been notified of this retraction. Notified R2DO(Lesser) and NMSS (Janosko).
ENS 42238	2 January 2006 10:38:00	10 CFR 76.120(c)(2)	Report of Safety Equipment Failure	At 0453 CST on 01/02/2006, the Plant Shift Superintendent (PSS) was notified that steam was observed leaking from the C-337A Position 1 West Autoclave. A 14 ton cylinder containing 0.711 % U235 assay uranium hexafluoride had been heating (TSR (Technical Safety Requirement) Mode 5) for approximately 5 minutes when the leak was observed. The autoclave pressure containment boundary is a TSR system required to be operable per TSR 2.2.3.1, 'Autoclave High Pressure Isolation System (HPIS),' when the autoclave is in Mode 5. The autoclave was placed in Mode 2, 'Autoclave Out-of-Service' in accordance with LCO Required Actions 2.2.3.1.C. 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 licensee noted that after steam was turned off to the autoclave, an inspection of the o-ring sealing surfaces did not identify any problems. No other sources of a steam leak could be found in the autoclave. The HPSI was declared inoperable due to a possible head-to-shell leak. The licensee will need to wait for a five day cool down time for the cylinder in the autoclave before it can be removed. Once the cylinder is removed, the autoclave can be re-pressurized in an attempt to determine the leak location. The NRC Senior Resident Inspector and DOE have been notified of this event. * * UPDATE AT 15:03 EST ON 01/18/06 FROM SKAGGS TO KNOKE * * * This notification is being retracted. On January 11, 2006, the 1 west autoclave was subjected to an autoclave pressure decay test. The autoclave passed the test on both the inner and outer containment valves. This proved that the steam leak reported by operators was not from a breach of the autoclave containment boundary, and that the AHPIS was performing as designed during the heat cycle initiated on January 2, 2006. Following the pressure decay test, steam was valved into the autoclave in an effort to find the steam leak. Steam vapor was seen under the autoclave at the location reported by operators on January 2, 2006. The steam vapor was discovered to be coming from a condensate blow-down hose that had moved away from the condensate drain housing allowing steam vapor to escape. No other leaks were noted. The successful autoclave pressure decay test provides evidence that the AHPIS was operable and available while the autoclave was in TSR Mode 5 on January 2, 2006, and thus the reporting criteria was not met. The NRC Senior Resident Inspector for PGDP has been notified of this retraction. Notified R2DO (Ogle) and NMSS Daytime EO (Morell)
ENS 42176	29 November 2005 14:45:00	10 CFR 76.120(c)(2)	Faulty Switch Rendered Criticality Accident Alarm System Inoperable	At 0845 CST, on 11/29/2005 the C-337 process building Criticality Accident Alarm System (CAAS) was being tested when a building horn control switch in C-300 Central Control Facility which supplies voltage to actuate the building CAAS evacuation horns was found to not be properly made up. This switch caused the building CAAS horns not to sound when a cluster was actuated. The test which revealed this problem, was the initial 'as found' test, which means the failure most likely occurred prior to today's testing. The C-337 CAAS system is a TSR system which is required to be operable in the current operating mode unless LCO actions are in place. The C-337 CAAS system was last tested on 11/05/2005 and indications are that the switch problem has existed since that time. During testing the CAAS alarm was received in C-300, but the evacuation horns did not automatically sound. Per procedure if a criticality alarm had occurred the C-300 operator would have actuated the horn switch manually which would have sounded the evacuation horns. To ensure that not only the C-337 switch was properly repaired, but also to verify all other building horn control switches were in the proper state, a plant wide LCO was implemented and switch outputs were checked to verify the proper voltage output. The NRC Senior Resident has been notified of this event.
ENS 41882	29 July 2005 02:25:00	10 CFR 76.120(c)(2)	Failure of Safety Equipment on C-310 Cylinder Valve Closure System	At 2125, on 7-29-05 the Plant Shift Superintendent was notified that the nitrogen bottle pressure for the C-310 Cylinder Valve Closure System was reading 0 psig. The function of this system is to close the cylinder valve in the case of an actuation of the UF6 Release Detection and Isolation System at the UF6 Withdrawal Station. TSR 2.3.4.1 requires this system to be operable while operating in mode 2. At the time the nitrogen bottle pressure was discovered to be reading 0 psig, withdrawal positions 3 and 4 were operating in mode 2. The UF6 Release Detection and Isolation System was declared inoperable by the PSS and withdrawal positions 3 and 4 were placed in mode 3 as required by TSR LCO 2.3.4.1. 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 nitrogen bottle normally maintains a pressure of 1500-2000 psig. The system malfunction was found on the daily equipment check by the operator.
ENS 41378	6 February 2005 16:08:00	10 CFR 76.120(c)(2)	24 Hour Report of a Safety Equipment Failure	The licensee provided the following information via facsimile: At 1008, on 2-06-05, the Plant Shift Superintendent (PSS) was notified that at the C-360 Toll and Transfer Facility on autoclave 4, the vent line block valve, XV-434, failed to close when the control switch was operated to the closed position. A check of the valve indicator showed that the valve moved to approximately 75% of the closed position. This valve is a single isolation point (no redundant valve) for two TSR (Technical and Safety Requirements) systems: (1) The Autoclave Steam Pressure Control System and (2) The Autoclave Water Inventory Control System. The autoclave was in mode 5, an applicable TSR mode for both systems. The PSS declared the systems inoperable and TSR LCOs 2.1.3.3 and 2.1.4.3 were implemented to remove the autoclave from service and place it in mode 2 within one hour. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120.c.2.i. It was 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 be 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.

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