ML20236Y159
| ML20236Y159 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 08/05/1998 |
| From: | Rainey G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Lieberman J NRC OFFICE OF ENFORCEMENT (OE) |
| References | |
| 50-353-97-09, 50-353-97-9, 50-353-98-02, 50-353-98-2, NUDOCS 9808110223 | |
| Download: ML20236Y159 (9) | |
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Cruel Nuclear offcer 7DR PECO NUCLEAR n's c!=;':03"1.eac.3 A Unit of PECO Energy
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l rax 61o 640 6611 graineyW peco-energycorn 10 CFR 2.201 l
August 5,1998 Docket Nos. 50-352 50-353 License Nos. NPF-39 NPF-85 James Lieberman, Director Office of Enforcement U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738
SUBJECT:
Limerick Generating Station, Units 1 and 2 l
Reply to a Notice of Violation and Payment of Civil Penalty NRC Enforcement Action 98-141 (NRC Inspection Report Nos. 50-353/97-09 and 50-353/98-02)
Attached is PECO Nuclear's reply to a Notice of Violation for Limerick Generating Station (LGS), Units 1 and 2, that was contained in your letter dated July 7,1998. The Notice concerned three violations that involved failures to identify and correct conditions adverse to quality, including instances where inoperability of safety-related equipment l
was not recognized. The attachment to this letter provides a restatement of the violations followed by our reply. A check in the amount of $55,000 for payment of the civil penalty is enclosed.
I If you have any questions or require additionalinformation, please contact us.
l Very truly yours, I
r 4N Enclosure Attachments cc:
H. J. Miller, Administrator, Region I, USNRC w/ attachments A. L. Burritt, USNRC Senior Resident inspector, LGS l
9908110223 990805 PDR ADOCK 05000353 G
Attachm::nt 1 COMMONWEALTH OF PENNSYLVANIA SS COUNTY OF CHESTER G. R. Rainey, being first duly sworn, disposes and says:
That he is President of PECO Nuclear; that he has read the attached Reply to a Notice of Violation for Limerick Generating Station, Units 1 and 2, and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.
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President Subscribed and sworn to before me this day of 4 AC 1996.
LJ GJ/auw
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Notaly Public NOTARIAL SEAL CAROL A.WALTON Notary Puten Olty of Philadelphia, PNia. County My Comedesion Expires May 28. 200t i
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Attrchm:nt 2 Dock:t Nos. 50-352 and 50-353 August 5,1998 Page 1 of 7 Reply to a Notice of Violation Restatement of the Violations During NRC inspections conducted between October 20,1997, and March 16,1998, for which exit meetings were held on January 16, 1998 and March 25, 1998, violations of NRC requirements were identified.
In accordance with the " General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1600, the Nuclear Regulatory Commission proposes to impose a civil penalty pursuant to Section 234 of the Atomic Energy Act of 1954, as amended (Act),42 U.S.C. 2282, and 10 CFR 2.205. The particular violations and associated civil penalty are set forth below:
1.
VIOLATIONS ASSESSED A CIVIL PENALTY 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action", requires, in part, that measures be established to assure that conditions adverse to quality, such as failures, malfunctions, and deficiencies are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.
a.
Contrary to the above, between January 8,1998 and January 28,1998, a condition adverse to quality existed, namely potential inoperability of HPCI exhaust valve due to internal binding, and although indications of this inoperability were provided when the valve failed to close on its first attempt on January 8,1998, and subsequent data provided indications of such internal binding, measures were not established to assure that this significant condition adverse to quality was promptly corrected until the valve again failed on its first attempt when tested on January 28,1998. As a result, between January 8, 1998, and January 28, 1998, the HPCI turbine exhaust valve, a primary containment isolation valve (outboard) was not maintained operable with a closing time less than or equal to 120 seconds. This is contrary to Unit 1 Technical Specification 3.6.3, " Primary Containment Isolation Valves," which requires, in part, that the primary containment isolation valves shown in Table 3.6.3-1 shall be operable with isolation times less than or equal to those shown in Table 3.6.3-1.
The HPCI turbine exhaust valve is listed as an outboard isolation barrier, with a maximum isolation time of 120 seconds.
b.
Contrary to the above, between September 1,1997, and January 21,1998, a condition adverse to quality existed involving the inoperability of the 1B residual heat removal (RHR) minimum flow valve (HV-051-F007B) after it was found closed on four occasions, and during that period, adequate corrective actions
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were not taken to correct this condition adverse to quality in that although an l
equipment trouble tag was initiated in each case to adC,ess the anomalous valve l
operation, the system was considered operable without adequate basis for doing so. As a result, between September 1,1997, and January 21,1998, the I
Docket Nos. 50-352 and 50-353 August 5,1998 Page 2 of 7 malfunctioning minimum flow valve caused the RHR pump to be inopersble and resulted in technical specifications being violated, namely:
1.
during this period, the suppression pool cooling mode of the "B" RHR system was not operable; this was contrary to Technical Specification 3.6.2.3 which requires, in part, that the suppression pool cooling mc,de of the RHR system shall be operable with two independent loops, each loop consisting of one operable RHR pump, and with one suppression pool cooling loop inoperable, the inoperable loop must be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
2.
the suppression pool spray mode of the "B" RHR system was not operable; this was contrary to Technical Specification 3.6.2.2. which requires, in part, that the suppression pool spray mode of the RHR system E,has be operable with two independent loups, each loop consisting of one operable RHR pump, and with one suppression pool spray foop inoperable, the inoperable loop must be restored to operable status within seven days.
3.
the low pressure coolant injection (LPCI) mode of the "B" RHR system removal system was not operable; this was contrary to Technical Specification 3.5.1.b which requires, in part, that the LPCI system of the RHR system be operable consisting of four subsystems with each subsystem comprised of one operable LPCI pump, and with one LPCI subsystem inoperable, the inoperable LPCI pump must be restored to an operable status within 30 days.
These violations represent a Severity Level ll1 problem (Supplement 1).
Civil Penalty - $55,000.
II.
VIOLATION NOT ASSESSED A civil PENALTY 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action," requires, in part, that measures be established to assure that conditions adverse to quality, such as failures, malfunctions, and deficiencies are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.
Contrary to the above, between August 1994 and October 7,1997, a condition adverse to quality existed, namely a reversed bearing on the D21 emergency diesel generator, and this condition adverse to quality was not promptly identified and corrected despite an opportunity to do so because of a prevbus reversed bearing on the D22 EDG at Limerick between December 1995 and May 1996.
This is a Severity Level IV violation (Supplement 1).
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g Attachm:nt 2 Dockst Nos. 50-352 and 50-353 August 5,1998 Page 3 of 7 REPLY TO VIOLATIONS ASSESSED A civil PENALTY Admission of the Violations PECO Energy acknowledges the violations.
Reasons for the Violations High Pressure Coolant injection (HPCI) System Turbine Exhaust Valve (l.a)
The cause of this violation was the station focus on the ability of the HPCI system turbine exhaust valve to perform its design basis safety function without ensuring that the valve would meet its licensing basis requirements prior to returning the valve to an operable status.
Evaluation of the failure of the HPCI system turbine exhaust valve to stroke fully closed on the first attempt focused on valve integrity and material condition, and its ability to perform its intended safety function. Valve HV-055-1F072 is a normally open valve. This valve is a safety related component and has an active safety function in the closed direction as a remote manual single primary containment isolation valve for a water sealed containrcent penetration, and a passive safety function to remain open during normal and post-accident HPCI system operation. This valve may be remote manually closed to isolate a suspected leak in the HPCI turbine exhaust line, i.e., a high energy line break (HELB), or to support primary containment flooding during an accident. This valve does not receive an automatic actuation signal, and does not have a specific analyzed requirement to operate during a Loss of Coolant Accident (LOCA), station blackout, or fire safe shutdown condition.
Although this valve does not have a specific closing time requirement to mitigate the consequences of a LOCA or HELB, the valve does have a licensing basis requirement in Limerick Generating Station (LGS) Technical Specifications (TS) Table 3.6.3-1 to stroke closed within 120 seconds. TS surveillance testing of this valve is required to be performed in accordance with the ASME Code Section XI inservice Testing (IST) program at LGS. As a result, the station considered that the closure time specified in TS was for use in evaluating the valve's performance when testing the valve in accordance with the IST program, and that troubleshooting activities and other actions taken to satisfy ASME Code Section XI requirements when the valve failed to stroke fully closed were sufficient to meet TS l
requirements. However, physical repairs were not made to the valve to ensure that the 120 l
second TS requirement would be met prior to restoring the valve to an operable status.
1B Residual Heat Removal (RHR) Pump Minimum Flow Valve (l.b)
I The cause of this violation was the failure to consider other pocsible failure mechanisms during the troubleshooting process to come to a timely resolution of the intermittent 1B RHR pump minimum flow valve closure. Troubleshooting of the initialinstances of the intermittent valve closure focused primarily on the flow transmitter, and did not consider the possibility of other instrumentation in the trip logic, such as the '. rip unit which was ultimately determined to be the cause of the valve closures.
Attachmsnt 2 Docket Nos. 50-352 and 50-353 August 5,1998 Page 4 of 7 i
The incorrect operability assessments were evaluated and determined to be caused by 4
inadequate LGS internal guidance provided to the shift crews on the conduct of operability determinations. Reviews of the guidance provided by NRC Generic Letter 91-18 when issued incorrectly determined that existing internal guidance at LGS was sufficient to make proper operability determinations. Therefore, no changes were made to the internal guidance at that time.
Corrective Actions Taken and Results Achieved Higin Pressure Coolant injection (HPCl) System Turbine Exhaust Valve (l.a)
Following the failure of the HPCI turbine exhaust valve to stroke fully closed on January 28, 1998, Unit 1 was shut down and the valve was disassembled and inspected. The valve was i
repaired and satisfactorily tested, and the system was declared operable on February 3,1998.
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l Similar high temperature, horizontally mounted valves on both units were disassembled and inspected with no problems identified. These valves included:
Unit 1 Reactor Core isolation Cooling (RCIC) system turbine exhaust valve, l
Unit 2 HPCI and RCIC system turbine exhaust valves, and Units 1 and 2 HPCI and RCIC system vacuum breakers.
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1B Residual Heat Removal (RHR) Pump Minimum Flow Valve (1.b) l l
l The failed Rosemount, Model 510DU, trip unit was replaced. The new trip unit was tested satisfactorily and the 18 RHR pump was declared operable on January 24,1998.
Corrective Actions to Avoid Future Noncompliance (Combined _1 The troubleshooting process at LGS has been enhanced by establishing an improved and ccmmon PECO Nuclear Administrative Guideline AG-CG-50," Equipment Investigation and Troubleshooting Guideline." This guideline establishes a standard systematic approach to i
troubleshooting with a technique that suggests sources and methods to be considered in identifying the cause of an equipment malfunction. This guideline also provides guidance for documentation of specific and pertinent information when a problem is initially identified, and provides guidance for the development of troubleshooting, repair, testing, and effectiveness assessment plans.
Programmatic evaluations were performed to determine if there was anything related to culture, education, knowledge, or real or perceived pressures that would prevent operators from l
declaring systems inoperable. No evidence of problems was identified in these areas.
l Strong corrective actions have been taken to raise station sensitivity to operability l
determinations. A common PECO Nuclear Operations Manus! Section OM-C-15.1,
" Operability," war developed based on the guidance provided in NRC Inspection Manual Part 9900: Technical Guidance, " Operable / Operability: Ensuring the Functional Capability of a.
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o, Docket Nos. 50-352 and 50-353 August 5,1998 Page 5 of 7 System or Component," and on existing guidance from a similar Peach Bottom Atomic Power Station specific guideline. Shift Management is required to be notified of all structure, system or component problems or conditions that could cause an adverse condition. Also, Shift Management is required to determine operability for all structures, systems or components in accordance with OM-C-15.1. In addition, training on making operability determinations based on the guidance provided in OM-C-15.1 has been conducted with station licensed operators.
1 An evaluation of processes that serve as inputs to making operability determinations has been performed to ensure that these processes provide a procer interface with Operations. These include: A-C-901, " Control of Nonconformances," LR-C-10, " Performance Enhancement Program (PEP)," A-C-26, " Administrative Control for Processing Work Orders," and A-C-43,
" Surveillance Testing Program." These procedures are being revised, as appropriate, to improve this interface.
1 All open Action Requests written against Technical Specifications related equipment were reviewed based on the guidance of OM-C-15.1. This review concluded that all current operability determinations were performed correctly.
A new barrier for operability determinations has been established. A currently licensed Senior Reactor Operator is required to attend the daily work review meeting to provide a licensed level review and verify proper sensitivity to any impact on operability. In addition, the Shift Manager and his staff are required to review Action Requests initiated on their shift to determine any impact on operability.
The PORC Chairman held a meeting with the Alternate PORC Chairmen and sent a letter to all
' PORC Members / Alternates to raise their sensitivity to station compliance with Technical Specifications when performing their oversight function at LGS.
I Date When Full Compliance was Achieved 1
High Pressure Coolant injection (HPCI) System Turbine Exhaust Valve (l.a)
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Full compliance was achieved by February 3,1998, when the HPCI turbine exhaust valve was repaired and satisfactorily tested, and the HPCI system was declared operable.
l 1B Residual Heat Removal (RHR) Pump Minimum Flow Valve (1.b) i Full compliance was achieved by January 24,1998, when the trip unit was replaced and 1
satisfactorily tested, and the 1B RHR pump was declared operable.
e, Attachm:nt 2
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Docket Nos. 50-352 and 50-353 i
l August 5,1998 l
Page 6 of 7 i
REPLY TO VIOLATION NOT ASSESSED A CIVIL.'ENALTY Admission of the Violation l
PECO Energy acknowledges the violation.
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Reasons for the Violation l
l The cause of the violation was a failure to recognize the potential safety significance and, l
therefore, the generic implications, of previously identified reversed Emergency Diesel Generator (EDG) bearings. As indicated in the referenced NRC Inspection Report No. 50-353/97-09, reversed bearings were identified on the E4 EDG at Peach Bottom Atomic Power Station (PBAPS) in June 1992, and on the D22 EDG at Limerick Generating Station (LGS) in May 1996. The safety significance of these conditions was not recognized until determination of the complex failure mechanism of the D21 EDG failure through extensive engineering l
evaluation and root cause analysis. The previous occurrences were perceived as individual maintenance installation errors only. This perception was based on the following contributing factors:
the reversed PBAPS bearing was found after 11 years of service with no impact on the e
operation of the diesel generator, there was no observable physical damage to either the PBAPS bearing or the D22 EDG e
bearing at LGS, there was no industry information indicating any concern with reversed EDG bearings, e
and the onsite EDG vendor field representative was consulted when the reversed bearings were identified in each of the previous two instances and did not indicate any potential impact or safety significance of the reversed bearings.
As a result, previous corrective actions were specifically targeted at the as found cornponents, review of maintenance procedures, and personnel training.
j Corrective Actions Taken and Results Achieved l
An inspection of Mth the lower and upper bearings on all eight Limerick Generating Station (LGS) emergency diesel generators (EDGs) was completed with no additional bearing reversals identified.
Corrective Actions to Avoid Future Noncompliance The following emergency diesel generator maintenance procedures were revised to enhance the instructions for the assembly of the EDG bearing rod to the crankshaft: M-020-009, " Main and Connecting Rod Bearing Examination and Maintenance," M-020-010, " Cylinder Liner, Piston, Piston Ring and Connecting Rod Replacement," and M-020-025, "5-Year Examination and General Maintenance." The procedure revisions added a double verification (with signoff) to ensure the correct connecting rod bearing orientation during the installation of each individual
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Docket Nos. 50-352 and 50-353 August 5,1998 Page 7 of 7 q
l bearing. Previously, a signoff was only required when installation of all bearings was completed. In addition, instructions were added to the procedures for marking of new replacement bearings, bearing dowel pin-to-hole alignment, and cotter pin installation.
Actions have been taken to reinforce the documentation of nonconforming conditions by the
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craftsmen and to reinforce the requirement to obtain written documentation of vendor J
recommendations and subsequent PECO Nuclear Engineering review of the recommendations.
I This issue was also included in training for maintenance craft personnel who perform work on the EDGs at both LGS and PBAPS.
Additional corrective actions were previously identified in PECO Nuclear's Special Report, dated November 10,1997, concerning the D21 EDG failure on October 9,1997.
l Date When Full Compliance was Achieved Full compliance was achieved on October 31,1997, when repair of the D21 EDG was accomplished by performing a complete five-year overhaul, a complete set of post-maintenance and performance tests were satisfactorily performed, and the EDG was declared operable again.
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