ML20205N932
| ML20205N932 | |
| Person / Time | |
|---|---|
| Issue date: | 10/31/1988 |
| From: | Beckjord E NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| RIL-158, NUDOCS 8811070111 | |
| Download: ML20205N932 (8) | |
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d.# n6s liEMORAliDUll FOR: Thomas E. I:urley, Director Office of f;uclear Reactor Regulation FROM: Eric S. Beckjord, Director Office of tiuclear Regulatory Research
SUBJECT:
RESEAkCH liiFORMATION LETTER fiUMBER 158:
CFERAT10!iAL SAFETY RELIABILITY PROGRAM
References:
- 1. NUREG-0600, "NRC Action Plan Developed as a result of the TMI Accident," Action item II.C.4, Reliab'11ty Engineering, August 1980.
- 2. Memorandum from liarold R. Denton to Robert D. Minogue, "fiRR User Research Request: Assessment of NRR Reliability Progran (RR-NRR-83-01)," February 14, 1983.
- 3. NUREG-1154, "Loss of Main and Auxiliary Feedwater Event at the Davis-Besse Plant en June 9, 1985."
- 4. Kepner, Charles H. and Benjamin B. Tregoe, "The flew Rational Manager," Princeton Research Press, 1981.
- 5. M. A. Azarm, E. V. Lofgren, et al., "Evaluation of Reliability Technology Applicabic to LWR Operational Safety," huREG/CR-4618, August 1968.
- 6. INP0 paper on "Safety Syster.: Perforrance," enclosed with letter from T. J. Sullivan, liiPO, to E. L. Jordan, NEC, April 15, 1988.
7 EPRI paper by John P. Gaertner, "A Review of Research Projects in the EFR1 fiuclear Power Division Systems Reliability Analysis Progran " presented at IEEE n.eeting in San francisco, July 14, 1987.
- 8. IEEE F933, Draft 7, "Guide fcr the Definiticti of Reliability Program Plans," itarch 1988.
- 9. "Final Cermission Policy Staterent en I:aintenance of Nuclear Power Plants," Federal Pegister Vol. 53, No. 56, March 23,1%8.
- 10. NRC Announcer.<nt !<o. 30, "Guidance on The Use of Porfurrance Irdicotors," February 5,1988. (
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Thomas E. Murley OCT 311933
- 11. NRC Five-Year Plan, March 1988.
- 10. SECY-88-103, "Status of Performance Indicator Program,"
April 15, 1988.
- 13. E. V. Lofgren, et al., "A Reliability Program for Emergency Diesel Generators at Nuclear Power Plants,"
NUREG/CR-5078, April 1988.
14 Temporary Instruction 2515/97, "Maintenance Inspection,"
June 1988.
- 15. J. Vora & J. Burns, "Understanding and Managing Aging and Maintenance," International Nuclear Power Plant Aging Syn posium, Bethesda, Maryland, August 30-Sept.1,1988.
This Research Information Letter identifies the elements and process of a reliability program that can help to raintain the safety of operating reactors. This process is being used in scveral NRC and industry initiatives, particularly regarding raintenance and managing the effects of plant aging, perforn.ance indicators, and technical specifications.
Regulatory issue In 1980, the TMI Action Plan (Item 11.C.4, Reliability Engineering) said that NRC would require licensees to develop reliability programs for NRC approval and implementation (Reference 1). Subsequently, hcwever, NRC did not mandate a reliability program because of both technical and institutional problems.
The technical problem was that the essential elen.ents and process of a reliability program applicable to operational safety had not yet been identified. Althcugh HRC requirerrents, such as Appendices A and E cf 10CFR50 strongly reflect reliability principles (i.e., safety trargins, redundancy, diversity, and corrective acticn); neycrtheless these principles had been applied primarily to nuclear power plants in the design phasc, and not in the operations phase. Reliability engineering practices at nuclear power plants had not yet been developed with strategies to help achieve and maintain the designed-in capability for reliable operation during 40 years of nuclear power plant operating life. Therefore, NPR asked RES to identify the elernents of such an operational reliability progran (Reference 2). This technical problem is now resolveo, neinly tnrough the research reported here and related work by industry.
The institutional problem, i.e., the difficulty of incorporating a reliability program into regulatory requirtrcnts, still persists. Prescriptive irplerrentation wcula be counter-productive because it could enccurage a licensee to focus on producing a "paper trail" for subsequent NRC inspecticos instead of focussing on raintaining plant perforrance. One way to enccurage reliable plant perfortrance withcut a prescriptive requirement for a reliability s
Thomas E. Nurley OCT 311GSS program is to require licensees to set availability / reliability / safety targets for overall plant performance or for selected systems, and to measure performance compared to the targets. Then NRC can focus on improvement programs for flagging performers. This ap generator reliability (Generic Issue B-56)proach is planned in support for diesel of the station blackout rule. ,
Conclusions In resolvirg the technical problem, this research surveyed the potential usefulness of a reliability pregram to help resolve generic issues and to prevent precursors. In the course of the study, RES visited 5 utilities; reviewed practices in other industries and other countries; and conducted a very limited trial application.
This research identified the essential eierents and process of a reliability program that can help to maintain the safety of nuclear pcwer plants during their operating lifetime. We conclude that an important characteristic of this process is its closed-loop characteristic. This closed-loop process, illustrated in Figure 1, includes monitoring plant safety performance; comparing performance with targets and identifying deviations, i.e., potential problems; prioritizing the deviations; and for the important problems, identifying the causes, taking corrective action, and monitoring plant performance to verify that the corrective action achieved its objectives (Reference 5).
Such a reliability program is airectly related to operational safety, as illustrated in Figure 2. For example, applying such on operational reliability program to balance-of-plant and other normally-operating equiprent helps to minimize. the occurrence of transients. Applying such a reliability program to standby safety systems helps to maintain their availability to respond when challenged. This process, based in part en widely used business principles (Reference 4), can help to focus attention ento important potential problems early on, and help prevent serious prcblens from occurring. This process integrates information on corponent failures, aging, and condition nonitoring, developed by activities such as NRC's Nuclear Plant Aging Research and INP0's huclear Plant Reliability Data System, into a top-down strategy to prevent safety rargins from degrading during the operating life of a plant.
Industry applications of this reliability technology to help raintain or improve crerational safety have been mixed. On the one hand, one utility recently discharged its reliability engineering group. On the other hand, the industry is supporting several reliability initiatives including: the Institute of Nucitar Power Operation's cperation of the Nuclear Plant Reliability Data Systen, and developrent of a risk-based Safety System Performance Indicatcr (Reference 6); the Electric Fewer Research Institute's adaptation and trial use of reliability-centered raintenance in operating plants (Reference 7); and the Institute of Electrical ano Electronics Enginu.rs' development of a guide for the definition of reliability program plans for operating plants (Reference 8).
Thomas E. Murley OCT 31 1988 Regulatory Application The elements of an operational reliability program are being opplied in several NRC and industry initiatives, such as technical-specification improvements, performance indicators, safety goals, nuclear plant aging research, and particularly irproved maintenance of nuclear power plants (References 9-11, 15).
For example, NRC's maintenance policy says: "The Commission defines ceinteniance as the aggregate of those functions required to preserve or I restore safety, reliability, and availability of plant structures, systems, I and components.... The program should include feedback of specific results to ensure corrective action, provisions for overall program evaluation, and the identification of possible corponent or system design problems" (Reference 9).
This feedback constitutes the closed-loop process illustrated in Figure 1.
Furthermore, the maintenance initiativt addresses both the diagnostic eyeluation of problems that have occurred and the prognostic identification of I important potential prcblems (Reference 14).
Table 1 shows how an operational reliabilit program is included in a raintenance program. InTable1, Column (1 lists the elements of an operational reliability program. Column (2 lists maintenance technical activities identified in the Corsnission's Policy Statement on Maintenance (Reference 9). Column (3)listsitemsonNRR'sMaintenanceInspection Tree (Reference 14). Three elements of a reliability program, although rot rentioned explicitly in Column (2), are understood to be included implicitly in a utility's raintenance progrom. These three eierents are: (1) assessing reliability / safety in design and operations, and setting objectives for the reaintenance program, (2) identifying and prioritizing potential problems, and (3) determining the causes of important potential prcblems. All these elements are included in NRC inspection of naintenance as shown in Column (3).
Thus, NRC's maintenance policy and inspection plan include the elements and closed-loop feedback process of a reliability program. In addition, individual aspects of a reliability program are being included in other NRC and industry initiatives, such as developtrent of risk-based plant performance indicators and improverent of technical specifications (Reference 11, 12).
Furthermore, an operational reliability program is part of the proposed resolution of Generic Issue B-56, "Diesel Generator Reliability" (Reference 13).
Restrictions on Applications An operational reliability program, I believe, can be impicn.ented more effectively in perforrance-based regulation (where NRC trandates the level of saf ety perforrance to be achieved) instead of in a prescriptive tranner (where NRC trar. dates the way to achieve the desired safety perfortrance).
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Thctnas E. Murley OCT 31 1988 Unresolved Ouestions and Further Work Research to evaluate the effectiveness of seie:ted applications of reliability engineering is continuing. In particular, we are evaluating an ircproved strategy tc prevent con on-cause failures (a follow-up item from the Davis-Besse loss of feedwater in 1985); i.e., what can be dor.e to help prevent multiple failures? (Reference 3).
In surrrnary, through this research and related NPC and industry prograrrs, the staff understands the elen.ents and process of an operational reliability prograrn. This understanding is being applied in several flPC and industry initiatives,
\sh Eric S. Beckjord, Director Office of Nuclear Regulatory Research
Enclosures:
As stated cc: V. Stello, ED0 A. C. Thadani,fiRR DISTRIBUTION:
J. M. Taylor, ECO J. W. Roe,fiRR . IGCC5 E. L. Jordan, AE0D A. T. Gody, NRR DSR Chren H. L. Thctrpson, HMSS E. M. McKenna,f1RR RES Circ /Chron W. T. Russell, R-! J. P. Jankovich, NRR HFRB Reading J. N. Grace, R-II F. J. Miraglia, NPR CJohr. son A. B. Davis, R-!!! T. Novak, AEOD TRyan R. D. Martin, R-IV H. Williains, AE0D FCoffrran J. B. Martin, R-V R. Singh, AE00 WMinners S. D. Ebneter, RI J. A. Axelrad, SP BSheron
- 11. L. Ernst, R!! C. I. Grirres, SP BMorris F. Gillespie, RES S. D. Richardson, SP TSpeis F. J. Hebdon,ilRR R. M. Bernero, NFSS Dross P. Cota, NRR R. E. Brcwning, lif tSS EBeckjord C. E. Rossi, NRR M. A. Taylor, EDO JMurphy P. W. Baranewsky, NRR B. l' orris, RES E. J. Butcher, NPR G. Arlotto, RES L. C. Shao, NRR R. W. Houston, RES R. F. Fraley, ACRS N. Dey,RES H. R. Denton, GPA T. King, RES J. G. Keppler, OSP ti. Vagins, RES W. G. Mcdonald, ARM J. Vora, RES R. W. Barber, DOE J. Murphy, RES J. Richardson, NRR FDR
- See previous concurrences.
R N; RhFB:DRPS RHFC:DRPS DD:DRPS DD:DSR D:DSR
- C chnson *TRyan *FCof f nan *Witinners *JMurphy *BSheron 6/28/E8 6/28/R8 6/28 8 7/15/EE E/10/88 9/23/E8
- DR / :RES E D:RES Bih>pris ( T peis t
D EBeckJ ord 1pr XS 10/d/68 10/ 88 10AT/88
FIGtfRE1 -
ELEfEMIE AND EBOCESS OF RELIABILITY PROGRAM 1
I 8
SOK t ASSESS j EVALUATE L M0!!!IOR PLANT. DEh!GNORA ONS:
- REllABILITY1 SAFETY L )
PERFORMANCE PERFORIMNCE (SETPERFORMANCETARGETjS
! POTENTIAL l PROBLEMS 1 . IMPLEMENT IDENTIFY a CORRECTIVE ACTION PRIORITIZE E VERIFY PROBLENS EFFECTIVEi;ESS i DETERMINE . , IDENTIFY CORRECTIVE ACTIDN EA!!SES l l
FIGURE 2 ,
HOW RELIARILITY PROGRAM RELATES 10 SAFETY ASSURE ACEEPTABLE SAFETY THROUGHOUT PLANT LIFE I 8 ASSURE LOW ASSURE HIGH DAFETY-SYSTEM FREQUENCY OF CHALLENGES AVAILABILITY I
1 I ASSURE ADEOUATE ASSURE RELIANILITY SAFETY-E0UIPMENT UP _0F UP SAFETY-EQUIPfENT 1~ I RELIABill1Y PROGRAM E
C0 dlGURATlhi ) REl.lABillTY PROGRAM APPLIED TO SAFETY-SYSTEMS APPLIED TO B0P a.
s FM AGEMENT APPLIED' (TYPICALLY STANDBY SYSTEMS) OTHER SYSTEMS THAT TO SAFETY-SYSTEMS -
ACCIDENTS (TYPICALLY OPERATING SYSTEMS)
TABLE 1 ,
RELIABILITY PROGRAM ELEMENTS ARE INCLUDED IN ,
LICENSEE MAINTENANCE ACTIVITIES AND NRC INSPECTION ,,
(1) RELIABILITY (2) MAINTENANCE (3) NRC IKSPECTION OF PROGRAM ACTIVITIES MAINTENANCE ELEMENTS l
' Assess Reliability /
- Establish policy, goals & objectives for maintenance Safety in design &
- Inspect role of PRA in maintenaitce program cperations; and set
- Identify prograr coverage for maintenance targets
- Define maintenance requirements I
' Monitor perfcrmance
- Surveillance ' Conduct performance measurement
- Maintenance records
- Maintain equipoent records & history
- Etaluate perforcance
- Equipment history & *Overall plaat performance related to asintenance, trending direct reasure .
- Information feedback
- Measures of overall
- Perform maintenance trending i program effectiveness l
l
- Identify & prioritize
- Establish deficiency identification & control system I problems
- Perform work prioritization
- 1dentify causes *Eng. support
- Inspect engineering support 1
- Crtermine corrective action
- Maintenance decision process
- Implement correctise action *CM
- Establish control of plant maintenance activities
- PM
' Predictive maintenance o
- Close-out problem
- Post maintrocnce
- Conduct post-maintenance testing testing & : turn-to-
- Review completed work documents service activities
- Inspect role of QC l *QA/QC b
-