ML20195D860
| ML20195D860 | |
| Person / Time | |
|---|---|
| Issue date: | 06/03/1999 |
| From: | Rossi C NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Jocelyn Craig, King T, Matthews D NRC (Affiliation Not Assigned), NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20195D865 | List: |
| References | |
| NUDOCS 9906100057 | |
| Download: ML20195D860 (2) | |
Text
I a
d p2 %q ,
[ t, UNITED STATES j
j t
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001
% # June 3, 1999 l
i MEMORANDUM TO: David B. Matthews, Director, DRIP:NRR ;
John W. Craig, Director, DET:RES l Thomas L. King, Director, DRAA:RES ,
j FROM: Charles E. Rossi, DirectdI' &r# f'WW ;
Division of Systems Analysis l and Regulatory Effectiveness !
Office of Nuclear Regulatory Research ,
SUBJECT:
AIR-OPERATED VALVES AT U.S. LIGHT WATER REACTORS -
= Attached for your review and comment are copies of draft report,
- Evaluation of Air-Operated Valves at U.S. Light-Water Reactors," initiated by the Office for Analysis and Evaluation of Operational Data, and completed by the Regulatory Effectiveness Assessment and Human -
Factors Branch Office of Nuclear Regulatory Research, and its companion document, Idaho National Engineering and Environmental Laboratory draft report, "A Study of Air-Operated Valves in Nuclear Power Plants," INEEUEXT-98-00383. The study objective was to provide an assessment of U.S. experience related to air-operated valves (AOVs) to help the NRC determine if additional attention needs to be focused on AOVs. We believe this report contains substantial and significant operational-based information that will be useful to the NRC in {
addressing the issues of AOV capability and operability.
The study was based on a comprehensive review of AOV operating experience and visits to 7 U.S. light water reactor sites at which there are 11 operating reactors. Participation by the j licensees was voluntary. Features of the AOV programs that were discussed included identification of risk-important AOVs, design margins, design verification, diagnostic testing,
//
maintenance practices, ageing, participation in industry AOV activities, parallelisms between //
AOV and motor-operated valve experience and activities.
The study includes information on over 100 events which include common-cause failures or degradations of AOVs in important systems such as emergency core cooling systems, residual heat removal systems, auxiliary feedwater systems, ernergency ac power systems, and boiling-water reactor scram systems.
h /0h CONTACT:. Harold L. Omstein (HLO), REAHFB:DSARE:RES (301)415-7574 ]
- glo N 9906100057 990603 4s- %
i e ._ .
'I e Multipl3 Addr:ssees 2 All of the plants visited had initiated AOV programs. Many but not all of the programs focus on activities to confirm the capability and operability of important AOVs. There are large plant-to-plant variations in the types, numbers, applications and risk importance of AOVs, and there are significant programmatic and schedular differences between the plants' AOV programs. The AOV programs at all of the plants visited used risk informed methodologies from the plant PRAs and maintenance rule to categorize the plant AOV populations.* Paralleling motor operated valve (MOV) experience, many licensees (in addition to those at the plants visited during this
. study) have used newly developed diagnostic equipment to discover deficiencies and weaknesses in the design, analysis, maintenance and testing of AOVs.
The AOV programs described in the study are voluntary and there are no explicit regulatory requirements goveming them. The study concludes that implementation of an effective AOV j program can minimize the likelihood for common cause AOV failures.
To meet our planned issuance schedule, we would appreciate receiving your comments by June 30,1999. This will allow time to resolve comments, further edit the revised report, and publish the final NUREG and NUREG/CR in August 1999.
It is our understanding that NRR will coordinate the review by and receipt of comments from the regions.
Attachments: As stated (7 copies to NRR)
)
cc w/atts.:
A. Blough, R-l j L. Plisco, R-Il G. Grant, R-Ill K. Brockman, R-IV '
ec w/o atts.:
B. Sheron, NRR j J. Zwolinski, NRR 1 G. Holahan, NRR J. Strosnider, NRR B. Boger, NRR W. Kane, NRR Distribution w/att.:
Public RSavio, ACRS WRifCiWhiiM RWessman, NRR REAHFB R/F AThadani, RES DSARE R/F MFederline, RES MKnapp, DEDE JMitchell, OEDO C:\WPDOCS\ STUDIES \1aovtran.wpd r
re "E' = Copy with attachment / enclosure To recohre
... _ a copy of thle document. Indicate in the box: 'C's Copy without attatFtt/
OFFICE REbbifA l .E REAHFB l CMEAHFB F::- D:DSARE C I
NAME HdRWelfi:m"mk GLanik JRosenthal CRos(f /fl DATE 6/ J/99 / /99 f /3/99 C/~4 W ~ ' '
OFFICIAL RECORD COPY N