Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 53239 | 1 March 2018 22:43:00 | 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | Potential Tornado Missile Vulnerabilities | During review of protection of equipment from damaging effects of tornados, Point Beach Nuclear Plant identified a potential vulnerability for the turbine driven auxiliary feedwater pumps due to steam supply piping that is not routed through a Class 1 structure. Immediate compensatory measures were taken to mitigate the potential consequences of a tornado generated missile impact. This condition is reportable per 10 CFR 50.72(b)(3)(ii)(B) and per 10 CFR 50.72(b)(3)(v)(A) and (D). The identified vulnerability is being addressed in accordance with EGM 15-002 and DSS-ISG-2016-01, enforcement discretion memorandum and interim guidance document for resolution of noncompliance with tornado-generated missile protection. The NRC Resident Inspector has been notified. | Auxiliary Feedwater | |
| ENS 52976 | 18 September 2017 22:24:00 | 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | Control Room Envelope Not Maintained | At 1724 (CDT) on 9/18/17 during Control Room Ventilation testing Door-61, South Control Room Door, became wedged against its door stop and stuck open. Door-61 is a credited High Energy Line Break (HELB) / Fire / Flood Barrier in addition to its function to maintain the Control Room envelope. The door stop was subsequently unbolted from the floor and the door was free to close. Door-61, South Control Room Door, has since been inspected, and at 1750 (CDT), was declared functional as a HELB / Fire / Flood Barrier and Operational for purposes of maintaining the Control Room Envelope. During the 26 minutes the door was stuck open, the Control Room was in an unanalyzed condition with regards to protection from a High Energy Line Break. The licensee notified the NRC Resident Inspector. | Control Room Envelope | |
| ENS 50262 | 8 July 2014 05:24:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Unit 2 Spray Addition Declared Inoperable Due to Tank Indication Greater than 67% | At 0024 CDT on 7/8/2014, Unit 2 Spray Addition was declared inoperable and LCO 3.6.7 (Spray Additive System) not being met, which resulted in a condition reportable pursuant to 10CFR50.72(b)(3)(v)(D). The inoperability was caused by Unit 2 Sodium Hydroxide Tank level indication greater than 67%, at 67.5%. This exceeds a current Prompt Operability Determination compensatory action requirement stating 'level shall be maintained no higher than 67%.' At 0104 CDT on 7/8/2014, Unit 2 Sodium Hydroxide Tank level was restored to an acceptable level, less than 67%. TSAC 3.6.7B was exited and LCO 3.6.7 met. The licensee informed the NRC Resident Inspector.
Point Beach is retracting EN# 50262 made on July 8, 2014 at 0628 CDT. The Operability Determination for this condition has been revised based upon engineering analysis. The event notification is being retracted based upon the subsequent Operability Determination revision that shows the NaOH Injection System was capable of performing its safety function at an observed Spray Additive Tank level of no higher than 77.2 percent. The licensee has notified the NRC Resident Inspector. Notified R3DO (Lipa). | ||
| ENS 48921 | 14 April 2013 11:20:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Containment Spray Chemical Addition Flow Path Isolated | At 0620 CDT on 4/14/13, the Unit 1 Sodium Hydroxide Tank outlet valve was found to be shut. This valve isolated the flow path for both trains of containment spray chemical addition and resulted in LCO 3.6.7 (Spray Additive System) not being met, which resulted in a condition reportable pursuant to 10 CFR 50.72(b)(3)(v)(D). At 0651 CDT on 4/14/13, the Unit 1 Sodium Hydroxide Tank outlet valve was restored to its required locked open position and TSAC (Technical Specification Action Conditions) 3.6.7.8 was exited. The licensee has notified the NRC Resident Inspector. | Containment Spray | |
| ENS 46646 | 28 February 2011 03:59:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Degraded Accident Mitigation Due to Safety Injection Out of Service | At 2159 CST on 2/27/2011, during the testing of the 'A' Train Safety Injection System, an Auxiliary Operator in the field identified that the oiler for 2P-15B, 'B' Train Safety Injection Pump, had rotated and the oil had drained out of the oiler. The Auxiliary Operator immediately reported this condition to control room personnel. The 'B' train safety injection pump was declared inoperable and LCO 3.0.3 was entered based upon the condition of both trains of safety injection being out of service. The Unit 2 'A' Train Safety Injection System was being tested in accordance with inservice testing procedure IT-535C, Leakage Reduction and Preventive Maintenance Program Train 'A' HHSI and RHR Piggyback Test Mode 1,5,6 (Refueling) Unit 2, which placed the Unit 2 ECCS in TSAC (Technical Specification Action Condition) 3.5.2.A, One ECCS Train Inoperable. Unit 2 exited LCO 3.0.3 at 2211 CST, upon completion of the 'A' train inservice test. The 2P-151B safety injection pump remains inoperable in accordance with TSAC 3.5.2.A, One ECCS Train Inoperable for troubleshooting and repair. This condition is reported in accordance with 10 CFR 50.72(b)(3)(v)(D) Accident Mitigation. There was no impact on Unit 1 and the licensee notified the NRC Resident Inspector. | ||
| ENS 43750 | 26 October 2007 00:30:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Both Low Temperature Overpressure Protection Systems Out of Service | This 8 hour report is being made pursuant to 10 CFR 50.72(b)(3)(v). On 10/25/2007 at 1930 CDT Point Beach Nuclear Plant (PBNP) Unit 1 and Unit 2 low temperature overpressure protection systems (LTOP) were declared inoperable as a result of the determination that the current LTOP actuation setpoint was non-conservative based on updated calculations. Specifically, 1) The mass input from the Safety Injection Pumps has significantly increased based on the use of a Point Beach Nuclear Plant specific system flow model. 2) The setpoint calculation does not consider instrument delay times during (PORV) Pilot Operated Relief Valve actuation. 3) The updated Calculation changes instrument uncertainties. LCO 3.4.12 for the LTOP system is not applicable at this time for either unit (both units in Mode 1/100% power). LCO 3.4.12 is only applicable in Mode 5, Mode 6 when the reactor vessel head is on, and Mode 4 when any cold leg temperature is at or below the temperature specified in the Pressure Temperature Limits Report (270 deg F). Changes to operating procedures to delineate operation of reactor coolant pumps and charging pumps during low temperature conditions are in progress. Implementation of these procedure changes will permit LTOP to be returned to service. The licensee stated that this issue was discovered as part of the on going calculation reconstitution initiative at the plant. The licensee notified the NRC Resident Inspector.
The following is an update to the 8 hr report made to the NRC via EN#43750: On 10/26/07 at 17:51 procedure changes which identify requirements for operation of reactor coolant pumps and charging pumps during low temperature conditions have been made. These procedures provide the guidance required to ensure that the current LTOP setpoints remain conservative. Based on the issuance of these procedures with the required guidance, LTOP is returned to service for both Unit-1 and Unit-2. The licensee notified the NRC Resident Inspector. Notified R3DO (Hills). | 05000266/LER-2007-008 | |
| ENS 43149 | 6 February 2007 20:15:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | Control Room Emergency Filtration System Declared Inoperable | The Control Room Emergency Filtration System (CREFS) was declared inoperable at 1957 on 02/03/07 due to W-14B, 'F-16 Control Room Charcoal Filter Fan,' being declared inoperable during monthly Technical Specification surveillance testing. Upon subsequent investigation of the inoperability of the W-14B fan, the W-14A fan was declared inoperable at 1415 CST on 02/06/07. The cause of the failure of the fans is under investigation. These fans are required to be operable to support operability of the CREFS System. This condition is covered by TS 3.7.9 'Control Room Emergency Filtration System' and both units have entered Action Condition A 'CREFS Inoperable,' with a Required Action to 'Restore CREFS to an OPERABLE Status' by 1957 CST on 02/10/07. Although the W-14 fans are redundant, CREFS is a single train system. Based on the guidance in NUREG-1022 for single train systems that perform safety functions, this condition was determined to be reportable under 10 CFR 50.72(b)(3)(v)(D), 'Event or Condition That Could Have Prevented Fulfillment of a Safety Function.' Additionally, the failure places PBNP CREFS in a degraded condition that significantly affects plant safety under 50.72(b)(3)(ii)(A), 'Degraded or Unanalyzed Condition.' The licensee notified the NRC Resident Inspector. | Control Room Emergency Filtration System | 05000266/LER-2007-001 |
| ENS 43040 | 9 December 2006 00:12:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Crefs System Inoperable | Control Room Emergency Filtration System (CREFS) was declared inoperable at 1812 on 12/8/06 because the W-14A, F-16 Control Room Charcoal Filter Fan tripped during performance of the monthly technical specification surveillance test, TS-9. This fan is required to be operable for operability of the CREFS System. This condition is covered by TS 3.7.9, Control Room Emergency Filtration System and both units have entered action condition A, 'CREFS Inoperable' with a required action to 'Restore CREFS to OPERABLE Status' with a completion time of 7 days. CREFS is a single train system. Based on the guidance in NUREG-1022 for single train systems that perform safety functions, this condition was determined to be reportable under 10CFR50.72(b)(3)(v), 'Event or Condition That Could Have Prevented Fulfillment of a Safety Function'.
On December 8, 2006, at 22.42 EST, EN 43040 was made by the Point Beach Nuclear Plant in accordance with 10 CFR 50.72(b)(3)(v)(D) as a condition at the time of discovery could have prevented the fulfillment of a system function that is needed to mitigate the consequences of an accident. Control Room Emergency Filtration System (CREFS) fan W-1 4A, F-16 Control Room Charcoal Filter Fan tripped during performance of the monthly Technical Specification surveillance test. CREFS was declared inoperable. After further evaluation, it was determined that the safety function of CREFS was not lost. Redundant fan W-14B was operable for the duration of the time fan W-14A was out of service. Single train portions of the system were not affected by the W-1 4A fan trip. Accordingly, this event is not reportable. EN 43040 is, therefore, retracted. Notified R2DO (Burgess) | Control Room Emergency Filtration System | |
| ENS 42611 | 30 May 2006 14:23:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Control Room Emergency Filtration System Inoperable | Control Room Emergency Filtration System (CREFS) was declared Inoperable at 0923 on 5/30/2006 per TS 5.5.10.c 'Ventilation Filter Testing Program'. Laboratory testing results of a sample of the charcoal adsorber taken on 5/2/2006 did not meet the methyl iodide penetration percentage acceptance criteria of less than or equal to 1.0%. This condition is covered by TS 3.7.9 and both Unit 1 and Unit 2 entered Condition A, 'CREFS Inoperable' with a Required Action of 'Restore CREFS to OPERABLE status' with a Completion Time of 7 Days. CREFS is a single train system. Based on the guidance in NUREG-1022 for single train systems that perform safety functions, this condition was determined to be reportable under 10 CFR 50.72(b)(3)(v), 'Event or Condition That Could Have Prevented Fulfillment of a Safety Function'. Technical Specifications allow this system to be inoperable for a period of seven days. This condition was not reported within the 8 Hour Non-Emergency reporting requirements. The charcoal has been replaced and the licensee estimates testing at approximately 17:00. The licensee notified the NRC Resident Inspector. | Control Room Emergency Filtration System | |
| ENS 42109 | 2 November 2005 05:00:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | Tech Spec Required Shutdown Due to Degradation of Containment Coatings | On November 2, 2005 at approximately 00:00 Central Standard Time (CST), Point Beach Nuclear Plant (PBNP) Unit 2 commenced a reactor shutdown required by Technical Specification 3.0.3. During a review of the containment coatings in both Unit 1 & 2 containments, it was discovered that the containments have not been maintained with the analysis of record performed by Sergeant and Lundy (S&L). The S&L analysis performed for Unit 2 was based on the known condition of coatings when the analysis was performed. There was no explicit margin for further degradation. Subsequent discoveries of degraded or unqualified coatings cannot be accommodated by the existing analysis as written. An Operability Recommendation (OPR) was performed for Unit 2 and approved on 10/30/05 at 2000. Following this OPR, a further review of containment coatings in the Unit 2 containment was performed and showed a potential for approximately 11 square feet of unqualified coatings (in) the Zone of Influence (ZOI) for the containment sump. The OPR allowed for a maximum of 5.68 square feet of loose material in the ZOI. A Unit 2 containment walk-down was performed on the evening of November 1, 2005. This revealed that the unqualified coatings in the ZOI were approximately 11 square feet. This information placed Unit 2 in an unanalyzed condition, which lead the operators to enter Technical Specification 3.0.3 at 2300 on November 1 due to both trains of Emergency Core Cooling System (ECCS) being declared inoperable for sump recirculation capability. Actions are currently underway to remove enough unqualified coatings to be within the assumptions made in the OPR and restore Containment Sump recirculation capability. When this is completed, the technical specification shutdown will be terminated, and Unit 2 will make preparations to return to full power. Unit 1 is currently in Mode 5 and ECCS is not required. However, the condition is also applicable to Unit 1 containment. Actions have been underway since the identification of the original issue to remove unqualified containment coatings. The Plant Manager has placed a hold on entering Mode 4 on Unit 1 pending completion of corrective actions. Presently there are 2 workers and a Radiation Protection technician inside containment. The licensee said that workers will go inside containment and remove the degraded coating. This will take approximately 45 minutes and have a total exposure to personnel of 85 millirem. The licensee notified the NRC Resident Inspector.
At 01:06 CST the licensee exited from Technical Specification 3.0.3. requirements and plans to hold power on Unit 2 at 97% power pending further assessment and evaluation. The licensee will notify the NRC Resident Inspector. Notified the R3DO (Kozak).
On November 2, 2005, at 01:13 (ET) PBNP submitted Emergency Notification #42109, to report a TS required shutdown due to potential of an unanalyzed condition that significantly degrades plant safety and an event or condition that potentially could have prevented the fulfillment of a safety function. The condition related to the discovery of degraded containment coatings in the zone of influence (ZOI) for the containment sump. A subsequent evaluation concluded that the degraded coatings would not have significantly affected sump recirculation flow capability. Additionally, the zone of influence was identified to be approximately one-third that assumed for the design-basis calculation. Based on the conservatism in the sump blockage analysis, the degraded coatings in the Unit 2 containment within the original ZOI did not affect the conclusion that equipment needed for accident mitigation would have operated as designed. Therefore, the Emergency Notification made on November 2, 2005, documenting that this condition created the potential of an unanalyzed condition that significantly degrades plant safety, and potentially could have prevented the fulfillment of a safety function, is retracted. The Technical Specification required shutdown is also retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (H. Peterson). | Emergency Core Cooling System | |
| ENS 41885 | 2 August 2005 01:00:00 | 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | Potentially Inoperable Safety Injection Pumps | As part of an ongoing calculation review project, design data is being evaluated on safety related motors. On 07/15/2005 at 2245, design data was accepted for 1P-15A Safety Injection motor. This data determined that during a design basis accident with degraded safeguards bus voltage, the 1P-15A Safety Injection Pump could trip and lockout on over current prior to the safeguards bus stripping on under voltage. The Safety Injection Pump lockout would then prevent an auto start of the Safety Injection Pump during Emergency Diesel Generator load sequencing. 1P-15A Safety Injection Pump was declared out of service at that time. No other safety related motors were affected by this data. The 1P-15A Safety Injection Pump time over current set point was adjusted, based on the revised motor data, returning 1P-15A to service on July 17 at 2230. 2P-15A Safety Injection Pump time over current set point was also conservatively reset. On 08/01/2005 at 2000, additional design motor data was accepted, which impacted the time over current set point for 1P-15B and 2P-15B Safety lnjection motors. Review of this data determined that a similar potential exists that during a design basis accident with degraded safeguards bus voltage, 1P-15B or 2P-15B Safety Injection Pump could trip and lockout on over current prior to the respective safeguards bus stripping on under voltage. The Safety Injection Pump lockout would then prevent an auto start of the Safety Injection Pump during Emergency Diesel Generator load sequencing. 1P-15B and 2P-15B Safety Injection Pumps have been declared out of service as a result of accepting this new data. Based on the combined effect of all received design motor data, a condition existed prior to 07/15/2005, which could have impacted the design function of Unit 1 or Unit 2 Safety Injection Pumps during a design basis accident with degraded safeguards bus voltage. Both Unit 1 and both Unit 2 Safety Injection Pumps had the potential for this effect to prevent auto start on the Emergency Diesel Generator Loading Sequence per design. Therefore, this condition is being reported under 10 CFR 50.72(b)(3)(v)(D) due to the potential to prevent fulfillment of a safety function to mitigate an accident. Previous corrective action has been completed for Unit 1 and Unit 2 P-15A Safety Injection motors therefore, they remain Operable and capable of fulfilling design safety function. The licensee is currently in a 72 hour Tech. Spec. LCO 3.5.2 (A) action statement for ECCS train B on both Units. Repairs are expected to take six to eight hours. Safety Injection train A equipment is being protected by administrative requirements put in place by the licensee. Operations personnel have been briefed of the potential impacts. The licensee notified the NRC Resident Inspector. | Emergency Diesel Generator | 05000266/LER-2005-004 05000266/LER-2005-003 |