ML20217Q392
| ML20217Q392 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/26/1997 |
| From: | Nunn D SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-361-97-99, 50-362-97-99, NUDOCS 9709030049 | |
| Download: ML20217Q392 (16) | |
Text
---
n h
sob 1HIRN CAUIORNK EDISON Ud2""
~
An LDISON INTLRN ATIO%AL Company August 26,1997
'.U.S. Nuclear Regulatory Commission
- ATTN: Document Control Desk
~ Washington D.C. 20555 Gentlemen:
Subject:
. San Onofre Nuclear Generating Station Comments Related to Systematic Assessment of Licensee Performance (SALP) Report 50-361/97-99; 50-362/97-99 On July 29,1997, the subject NRC SALP report was issued documenting the NRC's assessment of the San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 performance for the period of December 31,1995, through July 8,1997.
l
_ SCE accepts the SALP report's comments relating to pis.. performance in the Operations, Maintenance, and Plant Support SALP functional areas. However, based
. on our review of the SALP report, and the NRC inspection reports issued during the SALP period, we do not believe there has been a decline in engineering performance and, therefore, a superior rating has been maintained. The basis for this conclusion
- will be discussed at 1,,e SALP public meeting. The purpose of this letter is to provide additionalinformation' supporting SCE's assessment of Engineering's performance, and request the NRC to reconsider the Engineering evaluation based on this information (Enclosure).
SCE considers the Engineering area to be a significant strength and an asset to SONGS plant operation. SONGS performance in the area of Engineering was properly focused on safety, and has resulted in a superior level of performance. The SALP
_ report noted that the capability of SCE's engineering organization to conduct complex engineering activities continued to be superior, as well as superior engineering self-assessments and corrective action activities.
I SCE belle >es the Engineering area exemplifies superior performance when all the individual engineering SALP category elements are assessed and considered in the aggregate. SCE agrees that weaknesses were associated with the initiation of two new extensive programs (Maintenance Rule, and the voluntary Technical Spec'listion Improvement Program where SCE was a lead pilot plant). As discussed in the 4 Enclosure, the weaknesses were isolated and had no safety significance. SCE has P '9709030049 970826 PDR ADOCK 05000361 G PDR n ha C nt CA 92674 0128 -714 368-1480 Fax 714 368-1490 -
Document Control Desk 2 achieved significant accomplishments in the area of Engineering during the SALP period (as documented in the Enclosure), and believes that the minor weaknesses noted should not detract from our overa!! performance in this area. SCE management has consistently placed an emphasis on maintaining high quality engineering and believes a superior rating in the Engineering area is warranted. Accordingly, SCE requests the NRC reconsider the SALP rating in the Engineering
- area, if you should have any questions, or would like to discuss the issue further, please contact me.
Sincerely, I \\ s Enclosure cc: E. W. Merschoff, Regional Administrator, NRC Region IV i K. E. Perkins, Director, Walnut Creek Field Office, NRC Region IV M, B. Fields, NRC Project Manager, San Onofre Units 2 and 3 J. A. Sloan, NRC Senior Resident inspector, San Onofre Units 1,2 and 3
ENCLOSURE Engineering SALP Functional Area The information contained in this enclosure is presented in outline form delineating the NRC's SALP criteria, the SALP report engineering strengths, engineering challenges noted in the SALP report, engineering strengths noted in previous NRC inspection reports, and other major engineering accomplishments. As indicated by the information I provided below, SCE believes the performance in the Engineering area during the past SALP' period has consistently been properly focused on safety and compliance to NRC regulations, and has resulted in a superior level of performance. 1. SALP Category 1 Criteria A) Licensee attention and involvement have been' properly focused on safety and resulted in a superior level of safety performance, B) Licensee programs and procedures have provideci effective controls. C) The licensee's self-assessment efforts have been effective in the identification of emergent issues. 4 D) Corrective actions are technically sound, comprehensive, and thorough. Recurring problems are eliminated and resolution of issues is timely. E) Root cause analyses are thorough. II. Engineering strengths noted in the SALP report The associated SALP criteria is correlated with the SONGS performance as noted at the end in parenthesis. Outage Support " Strong performance was noted in engineering support to outages." (A) Engineering performance " Superior performance was noted in the resolution of complex engineering issues." (A)(D)(E) Self-Assessments "Self-assessment.. continued to be superior." (C) Corrective Action development and implementation " corrective action activities continued to be superior." (D) Root Cause Assessments of Industry Events "The Inc. pendent Safety Engineering Group performed excellent root cause assessments of industry events." (E)
i Enclosure Ill. Engineering challenges noted in the SALP Report implementation of the Maintenance Rule e SALP report comments:
- Engineering support to Maintenance lacked rigor and thoroughness for one significant program which resultedin a failure to develop an adequate program that would set goals and monitoring requirements for structures, systems, and components in accordance with the Maintenance Rule."
Additional NRC Information: As noted in the Maintenance Rule inspection report (IR 96-14), the NRC found on March 3,1997, that: " Noting the enhancements you have made to your Maintenance Rule implementation through the use of MREs and the conservative implementation of your program compared with industry guidance (length of time SSCs are monitored), we have decided, in this case, your i goals were adequate to monitor the corrective action." Discussion: At the Maintenance Rule predecisional enforcement conference held in the NRC's Region IV office in Arlington, Texas, on January 3,1997, the issue of the apparent failure to have goals and monitoring requirements established was discussed. SCE provided State of the System reports for the SSCs which address the Maintenance Rule goal setting requirements. Although the NRC did issue two Level IV violations in the Maintenance Rule inspection report, the NRC concluded that "neither of these violations had actual or potential safety significance and there were no instances where structures, systems, and components (SSCs) failed to perform their intended safety functior,s." Two important elements for successful implementation of the Maintenance Rule are:'(1) consideration of risk-insights; and (2) an aggressive corrective action system. ' As noted in the SALP report (and as discussed in other sections), SCE has strong programs for (1) utilizing PRA and the Safety t
Enclosure Monitor to bring risk-insights to the maintenance evaluations under the Maintenance Rule, and (2) an excellent corrective action program. In ovaluating the SALP report, we believe that these observations, which were made by our Nuclear Oversight organization, may have been taken out of context. For example, one Nuclear Oversight assessment performed to specifically address the failure to document Maintenance Rule goal setting evaluations, identified project management and management oversight as failed barriers. However, with respect to the overall implementation of the Maintenance Rule, another Nuclear Oversight assessment concluded that "the Maintenance Rule program and its implementation were deemed to be generally satisfactory, with several areas of strengths and areas for improvement noted." SCE believes it would be inappropriate to draw conclusions or comparisons from a self-critical assessment taken out of context. implementation of the Improved Technical Specification Program (ITS) e SALP report comments: "The project management of the improved TS conversion process did not properly scope the effort and engineering support was not sufficiently rigorous to ensure all surveillance requirements were properly verified by the implementing surveillance procedures. This resultedin a numberof design basis requirements that were not translated into appropriate operational requirements and surveillances and in missed opportunities to identify severallong-standing surveillance procedure deficiencies." SCE Perspective: The oriqinal charter of the ITS program was not to redefine every Limiting Condition for Operation (LCO) and Surveillance Requirement (SR) in the Technical Specifications, nor validate the accuracy of the existing Technical Specifications. The actual discovery of discrepancies in the ITS was made by an engineering supervisor who questioned the adequacy of procedural guidance in a surveillance procedure as satisfying the ITS requirements. When SCE recognized that the ITS conversion might not have been adequate and an engineering review to identify potential surveillance discrepancies was necessary, SCE's engineering organization promptly provided a comprehensive review. As noted in the SALP report, Engineering performance of this review was superior and, as discussed in IR 97-11, the examples identifiec during this review had limited actual safety significance. l
( 4 Enclosure Discussion: SCE agrees that the transition to the voluntary Improved Technical Specifications was not optimum. However, we believe this was due in large part to our understanding of what the ITS was intended to accomplish as discussed below. This understanding led to a decision by site management to limit Engineering's involvement when the ITS were being prepared, and when the ITS was being implemented. SCE has been actively involved in ITS for over 10 years. SCE volunteered to be the lead plant for Combustion Engineering plants. This included active participation with the NRC, NUMARC (NEI), the industry Owners Groups, and the various lead plants to prepare the draft standard technical specifications and to resolve the 28,000 comments received by the NRC on the draft standards. Throughout SCE's 10-year ITS involvement, ITS has consistently been represented as primarily accomplishing the following goals: (1) limiting the Technical Specifications to what truly should be there; (2) establishing a consistent operator friendly format; and (3) improving the Bases to the Technical Specifications. Although limited plant specific changes were to be permitted;it was never a goal that the ITS redefine individual LCOs and SRs. i This understanding of the ITS goals lead to the approach SCE adopted for the ITS implementation. Specifically, SCE elected to be ccnsistent with the approach used for implementation of other changes to the Technical Specifications. In particular, both in 1993 when the ITS submittal was being prepared, and in 1995/1996 when the ITS were being implemented, it was concluded that a review of design requirements in surveillance procedures by - Engineering was not required. However, in early 1997, Engineering independently identified discrepancies with implementation of several surveillance requirements. It became evident that a more detailed engineering review of the translation of surveillance requirements into the procedures was appropriate. A comprehensive review of all SRs, led by Engineering, was immediately initiated. As noted by the NRC in the SALP report, Engineering performance of this review was superior. This review found several subtle and longstanding deficiencies in our surveillances, some of which were exposed by format changes implemented by the ITS, even though they were not intended to be technical I
Enclosure changes. The corrective actions implemented from this review were timely, thorough, and comprehensive. On May 6,1997, SCE submitted Licensee Event Report 2-97-001, Revision 3, which reported the discrepancies associated with the ITS implementation that were identified by our surveillance program engineering review. This LER identified 14 separate examples, identified by SCE, where the surveillance requirements were not fully consistent with the associated surveillance procedures.' The overwhelming majority of these cases (12 of the 14 examples) represent instances where there was no intent by the ITS to. - change the manner in which the surveillance requirement was implemented. However, either because of wording changes associated with the standard technical specifications, or because of unrelated implementation errors (many of them longstanding), the actual surveillance testing did not comply verbatim with the surveillance requirements. Furthermore,9 of the 14 examples were due to implementation errors unrelated to the ITS (i.e., they involved errors dating as far back as 1982). However, there were no casos wtiere safety-related equipment was not properly maintained, nor were there any instances in which safety-related equipment was not capable of performing its intended safety function. In retrospect, SCE could have elected to perform an engineering review,- comparable to that performed earlier this year, during the initial ITS preparation or implementation process. However, based on our initial understanding of the changes expected with the ITS, this level of engineering - involvement did not seem appropriate either in 1993 when SCE was preparing the submittal, or in 1995/1996 when SCE implemented the new Technical- - Specifications. Once identified by Engineering, SCE did respond with n aggressive commitment of Engineering resources to this effort. Conective actions taken were comprehensive and thorough. This effort did not identify any safety significance condition. e inconel 600 instrument nozzles PWSCC SALP report comment: "SCE management missed an opportunity to replace Inconel 600 instrument nozzles with a history of susceptibility to primary water stress corrosion cracking [PWSCC]." _
o Enclosure SCE Perspective: SCO recently discussed the details of this issue with the NRC (reference: SCE public meeting with the NRC, dated August 21,1997). SCE believes that actions taken in 1995, in enacting an inspect and repair - approach to the RCS nozzle PWSCC, were in full accordance with our established program requirements. The inspect and repair program SCE has ' used since 1993 has resulted in the detection of PWSCC at San Onofre well - before any significant leakage developed. We believe our program is consistent with industry practices and supported by NUMARC/NEl and EPRI - guidance. The NRC and nuclear industry both agreed there was no safety significance to PWSCC, which would justify wholesale replacement of nozzles. SCE believes that the existing data in 1995 did not support an aggressive replacement of inconel 600 Hot Leg nozzles when viewed with other considerations (i.e., ALARA, economic, and engineering resources). For ) example, from an ALARA perspective, the dose rate associated with each hot leg nozzle replacement is approximately 1.7 person-rem per RCS nozzle, and 35 to 40 person-rem would have been expended to replace the remaining nozzles with heat number NX7630. Because the NRC ar.d industry agreed there was no safety significance to PWSCC which would justify replacement of nozzles, SCE concluded that replacement of nozzles was not necessary at that time and proceeded to: -1) qualify a replacement process in house to minimize plant impact; 2) explore other alternate replacement processes; 3) continue the inspect and repair - program through Cycle 9 (current outage); and 4) reevaluate our program plan follnwing the Cycle 9 outages. - On July 21,1997, after exiting the Unit 3 Cycle 9 outage, SCE assessed the Cycle 9 outage PWSCC inspection results, and decided to readjust our approach to RCS nozzle PWSCC accordingly. This adjustment is being incorporated into the planned program update, scheduled for October 31,1997. Our discussions with the NRC staff indicate they may have relied on a Nuclear Oversight assessment (SEA 97-002) as confirmation of their conclusions. SCE consistently recognizes the need to continually improve our performance and are very self-critical in our self-assessments. Nuclear ' Oversight assessments are intended to be highly self-critical, including the _ - _ _ _ _ _ _ _ _ - _ _ _ _ - _ _ _ _.
4 Enclosure use of hindsight to identify issues. Observations in these reports use all-information available at the time of the assessment. All such information may not have been available to organizations when decisions were made and actions were taken. The primary focus of the Nuclear. Oversight 97-002 self-assessment was on the failure of a pressurizer (not hot leg) water space nozzle which leaked during the March 1997 Unit 2 start-up. The self-assessment conservatively _ concluded there was a missed opportunity for early identification at the start of the Unit 2 outage, as the presence of shims and a retaining clamp did not allow for a clear view of the nozzle, and may have hidden evidence of leakage. The 97-002 self-assessment also noted that a pro-active approach to replacing nozzles might also have been a missed opportunity. While the report focused on pressurizer water space nozzles, it called for an overall strategy review after the Unit 3 Cycle 9 refueling outage, based on the Unit 2 i Cycle 9 outages experience. Nuclear Oversight reports do not attempt to make balanced judgements of the reasonableness of actions and decisions by organizations or individuals. Instead, the reports use a self critical approach to provide the most comprehc.. ive analysis possible to identify lessons learned and improve performance. When reviewing Nuclear Oversight documents, the self-critical e rapproach and the context of individual statements must be considered. SCE's inconel 600 nozzle self-assessment is an example of this self-critical-- approach. it was directed at improving performance and was not a balanced evaluation of the overall inconel 600 program. SCE believes that our
- engineering performance for the inconel nozzle program was appropriate and i
adequate based on the information available during the 1995 time frame. IV. ' Engineering strengths noted in other NRC Inspection Reports This section provides additional Engineering strengths as noted in previous NRC ' inspection reports issued during the SALP-period. Corresponding SALP criteria, as 4 delineated in Section I above, are also provided in parenthesis for reference. _ - _ _ - -
Enclosure Inspection Report 97-12 -The licensee's identification of the charging system check valve flow e imbalance, the resultant technical review, and initial corrective actions were excellent. (A)(B)(D) The licensee's efforts to resolve the degraded egg crate condition were excellent. The licensee thoroughly inspected the Unit 3 steam generator (SG) internals to quantify the extent of degradation, and developed a comprehensive strategy to identify and address all relevant technical issues related to operation of Unit 3. The licensee provided extensive technical support for the meetings held with the NRC staff, and provided timely, and accurate responses to NRC staff questions on this issue. (A)(B)(D)(E) Inspection Report 97-09 in general, engineering support was excellent. (A)(B)(D) e The licensee's root cause assessment and corrective actions, associated with e 26 recent failures of excore nuclear instrument channels, were excellent, and included the use of vendor technical support. (A)(D)(E) Inspection Report 97-05 Reactor Engineering pro actively used the four safety power channels, in addition to the required use of the two startup channels, to provide criticality projections.- An extra hold point was also added during the startup to ensure that the projections were conservative. (A)(B) Inspection Report 97-02 The root cause assessment of a failed RCS thermowell was extremely thorough and represented substantial technical depth. (E) Engineering's evaluation and support of the steam generator (SG) chemical =
- cleaning process were thorough and excellent. (A)(B)(D)(E)
The licensee's Independent Safety Engineering Group (ISEG), in conjunction with Nuclear Engineering Des _ign and Station Technical, demonstrated aggressive and prompt response to two notifications of generic problems. (A)(B)(D)(E) .g. 1
9 4 9 Enclosure A safety evaluation performed to determine the acceptability of leaving some debris in the reactor vessel was rigorous. (A)(B) The licensee's engineering analysis, and testing done at a contracted laboratory, were aggressive in identifying and minimizing irregularities with the containment high range radiation monitors (HRRMs). (A)(B)(D)(E) Inspection Report 96-17 Licensee efforts to identify and correct a high energy line break interaction - through ventilation ductwork to other spaces housing environmentally sensitive equipment was indicative of strong, proactive engineering. (A)(B)(D) Inspection Report 96-15 On October 22,1996, the breaker for Charging Pump 2Pl90 failed to close on demand from the control room it failed to close on a second attempt, and on a third attempt it closed and then tripped open after approximately 3 minutes. The licensee's resolution of a failed 480 volt safety-related breaker was prompt and thorough. (A)(B)(D)(E) While reviewing vendor calculations as part of the reload technology transfer program, licensee engineers identified a discrepancy in the data related to core power distributions for dropped part-length CEAs (FLCEAs). The licensee's identification and correction of a methodology error in a vendor calculation was an excellent finding demonstrating strength in the licensee's reload technology transfer program. (A)(B)(D) Inspection Report 96-13 (Cover Letter] Our inspection found that your self-assessment of engineering was a thorough and comprehensive alternative to the planned NRC team inspection in this area. (C) The licensee's engineering self-assessment team concluded, overall, that San =- Onofre Nuclear Generating Station engineering was meeting program requirements. The team noted the following strengths in the engineering areas reviewed: (C) 9-
.c Enclosure San Onofre Nuclear _ Generating Station had strong engineering departments. The engineering staff was knowledgeable, experienced, and exhibited strong analytical capabilities. (A) Engineering was responsive to plant safety / operability issues.(A) . The Nuclear Engineering Design Organization generated fundamentally sound designs that worked well.(B)(D) Engineering computer tools and trending were comprehensive.(A)(B) Inspection Report 96 The licensee's root cause investigation and actions to prevent recurrence for inadvertent radiation monitoring (RM) annunciation were aggressive. (A)(B)(D)(E) Inspection Report 96-09 The licensee was proactive in initiating modifications to allow timely cross connection of Units 2 and 3 emergency diesel generators (EDGs) to improve site safety. (A)(B)(D) Inspection Report 96-06 Installation of the [ Unit 1) SFP leak detection indicating system represented
- -an excellent initiative to enhance the quality of information provided to the operations staff in their assessment of safe spent fuel storage. (A)(B)(D)
Inspection Report 96-03 [ Cover Letter) We also continue to highly regard your sound response to emerging technical problems. For example, you demonstrated a safety conscious approach in your resolution of the stratified boron in a refueling water storage tank, and in your identification and response to auxiliary feedwater system reliability issues. (A)(B)(D)(E) Findings by the Nuclear Safety Group, as a result of a risk assessment of a plant occurrence involving an overspeed trip of the turbine-driven auxiliary,
_ - _ _ - _ - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ = _. L' _ Enclosure 1 feedwater pump, represented thorough, safety-conscious work. - Additionally, - the management response to the issues was appropriate and conservative (A)(B)(D). Station Technical response to an increasing temperature trend on a reactor coolant pump (RCP) motor upper thrust bearing was prompt and thorough. (A)(B)(D)' Inspection Report 96-02 in response to the overspeed trip of Unit 3 turbine-driven auxiliary feedwater e pump during an Inservice Test, the licensee's initial root cause investigation and operability assessment were thorough and appropriately concluded that the pump was operable with the conditions specified/ The Vice President, Nuctear Generation's decision to shut down the unit if the pump tripped before the maintenance could be accomplished was conservative and appropriate. (A)(B)(D)(E) . Engineering involvement in the data collection and analysis and in the e development of the plan to prevent future overspeed conditions was excellent, and the 10 CFR Part 50,59 safety evaluation appeared to be thorough. The identification of some historical anomalies in the trip-throttle valve pilot delay time reflected thoroughness on the part of the licensee's staff. (A)(B)(D)(E) V. Other Major Engineering Accomplishments Maturation of the AR system involved over 7500 engineering assignments e being closed in the current SALP period (operability assessments, field support requests, engineering cause and betterment items) and significantly lowered the threshold of problem identification. Utilization of the Safety Monitor PRA-insights in day-to-day maintenance activities maintains plant configuration in the safest possible configurations. Outage risk evaluations ensure work activities are planned and conducted maximizing overall plant safety. Engineering supported improvements to SG chemistry and reduction in corrosion products, primarily iron, to lowest practical levels (increased pH, ETA, titanium oxide addition, experiments with prototype filters). The Steam Generator Strategic Management Plan was reviewed by an interdisciplinary task force and outside industry experts. - - _____________ _ _ _ _ _ _ - _
Enclosure One of the first to undertake a Comprehensive review of the UFSAR accuracy, e which is expected to result in over 53,000 person-hours of engineering review. Reactivated the Design Basis Documentation (DBD) program for the Emergency Diesel Generator and for Containment Systems. It is expected this effort will expend over 30,000 person-hours of engineering review. Utilization of the Event Report system reduced the threshold for self-assessment and trended activities to improvo performance. implemented a State of the System Report which is accessible to all site e personnel on the Site Network computer system. The report is effective in early identification of adverse trends, assists in focusing resources to solve problems, and assists in achieving Maintenance Rule goals. Have seen continued improvement of the comprehensive computer based IST program. The program is an industry standard. Appendix J programs are performing at a Superior level. LLRT/lLRT performance is a leader in the industry. Created a valve support group to improve engineering oversight and activities for MOVs, AOVs, and check valves. Continued developed of AOV program and diagnostic testing of valves. Implemented non-intrusive testing of several critical check valves. Resolved a Turbine Auxiliary pump overspeed problem by re-engineering time delay opening of steam admission valve within the constraints of an action statement. Significantly increased TDAFWP reliability. Discovered and implemented corrective actions to repair cracks in low pressure turbines at various blade attachment points. No unplanned generation loss due to this potentially serious problem. Initiated purchase of new LP rotors and implemented new exhaust hoods one cycle early. During Cycle 8, Unit 2 and Unit 3 fuel performance was below the zero fuel failure level as defined by INPO. During Cycle 8, and after the startup of Cycle 9, Unit 2 has indicated that it has a small leaking fuel pin, which is only identifiable during power changes. This is indicative of superior fuel performance over the two cycles. 1
.~ Enclosure et Early identification and implemented mitigative corrective actions to offset a slowly degrading Excore Channel detector without loss of availability or safety margin. Implemented generic Shape Annealing Matrix improving CPC axial shape e synthesis for a variety of axial power shapes and optimizing restart physics testing. Resolved repeated failures of Excore Detector, Sub-Channel Linear Gains Cards. Implemente'd enhanced Integrated Engineered Safety Feature Actuation System testing data gathering equipment, Replacement of Post LOCA Hydrogen Monitoring system significantly increased reliability. -Implemented Service and instrument air performance improvements e correcting reliability and original equipment design problems. Corrected low pressure turbine valve gland sealing leakage problems. Corrected 'several design problems with Salt Water Cooling discharge check valves significantly improving reliability. Replaced off site dose computer with State-of-the-Art RADOS V. Designed and buiIt QSPDS on-line testing system significantly improving system availability during outages. . Upgraded chlorination system controls reducing NPDES permit violations and improving system reliability and effectiveness. Implemented use of HYDRAN online transformer monitoring system. e Improved CPC/CEAC reliability by adjusting memory access time. Resolved containment high-rad monitor cable problem. Significant engineering input to the 50.54(f) response to the NRC on_ design issues. _ -
. =. Enclosure -> Focused management attention has resulted in a significant reduction in - engineering backlog.' L o -- Comprehensive response to NRC Generic Letter 96-06, equipment operability - concerns during design basis accidents, Aggressive actions taken to respond to NRC Generic Letter 96-01 for Plant o Protection System surveillance. testing. i i -: I _ - - - _ - _ _ _. - -}}