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 Start dateReporting criterionEvent description
05000305/LER-2012-0093 December 201210 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

On December 10, 2012, while in Mode 1, Technical Specification (TS) Limiting Condition for Operation (LCO) 3.8.1, "AC Sources - Operating," Condition B, Required Action B.1 was discovered to have not been completed within the required Completion Time, following one Emergency Diesel Generator (EDG) (DG) being made inoperable for scheduled "B" train maintenance on December 3, 2012. Required Action B.1, to "Perform SR 3.8.1.1 for the offsite circuit(s)," had been performed, with acceptable results, for the initial 1 hour Completion Time immediately following the EDG being declared inoperable.

However, it was not fully performed "Once per 8 hours thereafter for the two subsequent 8 hour periods.

The EDG was restored to operable less than 24 hours after being made inoperable and thus LCO 3.8.1 was met and Required Action B.1 was no longer applicable.

This incomplete surveillance was due to a missing page in the procedure directing the performance of the Surveillance Requirement (SR). Upon discovery one week later, a prompt review of computer trend data for that time period showed the SR 3.8.1.1 acceptance criteria were met.

This event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for any operation or condition which was prohibited by the plant's Technical Specifications.

05000305/LER-2012-00618 July 201210 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

At 1555 CDT on July 18, 2012, while in Mode 1, Technical Specification (TS) Limiting Condition for Operation (LCO) 3.7.12, Auxiliary Building Special Ventilation (ASV) System, was discovered not met for Train A. This was due to the ASV Train A charcoal sample failing its efficiency test. The test sample was less than the minimum efficiency of 97.5% required by the criteria in TS 5.5.9; Ventilation Filter Testing Program (tested efficiency was 97.13%). With the Train A charcoal filter media efficiency below the test criteria, the associated train of ASV did not meet its TS Surveillance Requirement (SR). Per SR 3.0.1, failure to meet a Surveillance shall be failure to meet the TS Limiting Condition for Operation (LCO). Therefore, LCO 3.7.12, ASV System, was not met for Train A.

The SR was considered to have not been met from the time that the charcoal sample was removed for testing (July 11, 2012) until the charcoal filter was replaced (July 21, 2012). With the charcoal filter not meeting its SR for this period, LCO 3.7.12 was also not met for ASV Train A for a longer period than allowed by Technical Specifications. Thus, this event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for any operation or condition prohibited by the plant's Technical Specifications. Earlier on July 18, 2012, ASV Train B had been removed from service for routine maintenance and was inoperable for about six hours.

05000305/LER-2011-00630 August 201110 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

During routine surveillance testing of the control rod system on August 30, 2011, a rod control urgent failure alarm was received, indicating an electrical fault in the control rod drive system. Surveillance activities were temporarily suspended upon receipt of the urgent failure alarm while troubleshooting activities were carried out to address the cause of the urgent failure alarm. Control Bank A Group 2 was one step outside the required insertion limit at the time of the event. However, the provision of a Note in the applicable Technical Specification (TS), which provided an allowance that waived certain requirements of the TS while performing the surveillance, was being used to maintain compliance with the TS. The cause of the urgent failure alarm was not readily resolved and troubleshooting activities continued into the following shift.

During subsequent evaluation of this event, use of this TS Note to maintain compliance with TS while the surveillance was suspended for an extended period was determined to be inappropriate.

Consequently, the TS was no longer met and the required actions should have been taken. The inappropriate use of this Note was not recognized until the following day, by which time the required actions could not be carried out within the completion time of the TS. Therefore, this event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for any operation or condition prohibited by the plant's Technical Specifications.

05000305/LER-2011-00431 March 201110 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

At 1744 CDT on March 28, 2011, with reactor power being raised while in Mode 1 following a refueling outage, one offsite AC electrical source became inoperable. The inoperability was due to operators' adjusting transformer load taps on that circuit, without adequately communicating information to the offsite grid operator regarding the onsite electrical demand caused by the specific configuration of operating plant equipment, such that predicted post-trip electrical grid voltage decreased below acceptance criteria.

This condition was not discovered until March 31 at 0245, following which, the transformer tap settings were properly adjusted and the electrical circuit restored to an operable status at 0255.

With one offsite AC electrical source inoperable, Technical Specification (TS) 3.8.1, Required Action A.1, applies. Required Action A.1 has a Completion Time of one hour. Performance of Required Action A.1 was not done prior to discovery of this condition. Therefore, this event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for any operation or condition prohibited by the plant's Technical Specifications.

05000305/LER-2011-00324 March 201110 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

At 1125 CST on March 24, 2011 with the plant shutdown and in Mode 3, it was identified that the electrical breaker for motor operated valve SI-11A, Safety Injection to Loop A Cold Leg, was in the ON position with the valve open, instead of the required breaker position of LOCKED OFF for the plant conditions as required by Technical Specifications. The valve itself was properly in the open position and was thereby providing the required safety injection flow path.

The breaker being mispositioned was as a result of performance of procedure SP-33-297A, Safety Injection to Loop A Cold Leg Check Valve Leakage Measurement. As written, the procedure did not provide direction for performing valve breaker manipulations, nor did it include steps to verify valve SI- 11A was in the open position upon completion of the check valve leakage measurement activities.

When the condition was identified, SI-11A was verified open and the breaker was placed in the OFF position and LOCKED.

This event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for any operation or condition prohibited by the plant's Technical Specifications.

05000305/LER-2011-00210 March 201110 CFR 50.73(a)(2)(iv)(A), System Actuationor in NRC Form 366A
05000305/LER-2011-00113 December 201010 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specificationsor in NRC Form 366A
05000305/LER-1986-009, Forwards LER 86-009-00.Delay in Submitting Rept 2 Days Beyond 10CFR50.73 Requirement Necessary to Include Results of Special Test Procedure Performed as Final Corrective Action for Event.Delay Concurred W/By NRC Project Manager16 June 1986
05000305/LER-1983-011, Forwards LER 83-011/03L-018 April 1983
05000305/LER-1983-008, Forwards LER 83-008/03L-08 April 1983
05000305/LER-1983-007, Forwards LER 83-007/01T-0.Detailed Event Analysis Submitted7 April 1983
05000305/LER-1983-006, Forwards LER 83-006/03L-023 March 1983
05000305/LER-1983-005, Forwards Updated LER 83-005/03X-13 May 1983
05000305/LER-1983-004, Forwards LER 83-004/03L-04 March 1983
05000305/LER-1983-003, Forwards LER 83-003/03L-03 March 1983
05000305/LER-1983-002, Forwards LER 83-002/03L-025 February 1983
05000305/LER-1983-001, Forwards Updated LER 83-001/01X-116 March 1983
05000305/LER-1982-036, Forwards LER 82-036/03L-027 January 1983
05000305/LER-1982-034, Forwards LER 82-034/03L-010 December 1982
05000305/LER-1982-033, Forwards LER 82-033/03L-019 November 1982
05000305/LER-1982-032, Forwards LER 82-032/03L-03 November 1982
05000305/LER-1982-030, Forwards Updated LER 82-030/01X-11 February 1983
05000305/LER-1982-028, Forwards LER 82-028/03L-0 & Updated 81-036/03X-124 September 1982
05000305/LER-1982-026, Forwards LER 82-026/03L-031 August 1982
05000305/LER-1982-023, Forwards LER 82-023/03L-010 August 1982
05000305/LER-1982-021, Forwards Updated LER 82-021/01X-1 & LER 82-027/03L-010 September 1982
05000305/LER-1982-020, Forwards LER 82-020/03L-030 July 1982
05000305/LER-1982-019, Forwards LER 82-019/03L-028 July 1982
05000305/LER-1982-018, Forwards LER 82-018/03L-02 July 1982
05000305/LER-1982-01724 June 1982
05000305/LER-1982-01623 June 1982
05000305/LER-1982-015, Forwards LER 82-015/03L-018 June 1982
05000305/LER-1982-014, Forwards LER 82-014/03L-015 June 1982
05000305/LER-1982-01311 June 1982
05000305/LER-1982-01211 June 1982
05000305/LER-1982-011, Forwards LER 82-011/03L-028 May 1982
05000305/LER-1982-010, Forwards Updated LER 82-010/03X-1 & LERs 82-012/03L-0 & 82-013/01T-011 June 1982
05000305/LER-1982-009, Forwards Updated LER 82-009/03X-15 August 1982
05000305/LER-1982-006, Forwards LER 82-006/03L-013 April 1982
05000305/LER-1982-0057 April 1982
05000305/LER-1982-0047 April 1982
05000305/LER-1982-002, Forwards Updated LER 82-002/03X-1 & LERs 82-024/03L-0 & 82-025/03L-013 August 1982
05000305/LER-1981-037, Forwards LER 81-037/03L-09 December 1981
05000305/LER-1981-036, Updated LER 81-036/03X-1:on 811103,motor Drive Auxiliary Feedwater Lube Oil Pump Continued to Run When Pump 1A Stopped.Caused by Excessive Wear & Misalignment of Switch Linkage Mechanism.Worn Parts Replaced21 September 1982
05000305/LER-1981-006, Forwards LER 81-006/03L-026 March 1981
05000305/LER-1978-024, Forwards LER 78-024/03X-09 October 1978