ML17312A859
| ML17312A859 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/12/1996 |
| From: | Gwynn T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Stewart W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 9607170233 | |
| Download: ML17312A859 (16) | |
Text
CATEGORY 2
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RZDS)
ACCESSION h'BR:9607170233 DOC.DATE: 96/07/12 NOTARIZED:
NO DOCKET ACZL:STN-50-S28 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH.NAME AUTHOR AFFILIATION GWYNN,T.P.
Region 4 (Post 820201)
'F5-23'ECIP.NAME RECIPIENT AFFILIATION STEWART,W.L.
Arizona Public Service Co. (formerly Arizona Nuclear Power C
SUBJECT:
Forwards several comments in response to 960419 ltr which provided suppl info re motor-operated valve program.
A DISTRIBUTION CODE:
IEOID COPIES RECEIVED: LTR L ENCL I SIZE:
7 T
TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response NOTES:STANDARDIZED PLANT Standardized plant.
Standardized plant.
RECIPIENT ID CODE/NAME PD4-2 PD CLIFFORD,J.
COPIES LTTR ENCL 1
1 1
1 RECIPIENT ID CODE/NAME CLIFFORDIJ COPIES LTTR ENCL 1
1 05000528 05000529 G
05000530 0 INTERNAL: ACRS AEOD/
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AEOD/SPD/RAB DEDRO NRR/DZSP/PIPB NRR/DRPM/PECB NUDOCS-ABSTRACT OGC/HDS2 1
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1 1
1 1
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EXTERNAL: LITCO BRYCEIJ H
NRC PDR 1
1 1
1 NOAC 1
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N NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE!
CONTACT THE DOCUMENT CONTROL DESKS ROOM OWFN SD-5(EXT. 415-2083)
TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDl TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL 20
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UNIT E D STATES NUCLEAR REGULATORY COMMISSION REGION IV 611 RYAN PLAZA DRIVE, SUITE 400 ARLINGTON,TEXAS 76011 6064 Jm. t2eS William L. Stewart, Executive Vice President.
Nuclear Arizona Public Service Company P.O.
Box 53999
- Phoenix, Arizona 85072-3999
SUBJECT:
SUPPLEMENTAL INFORMATION NRC INSPECTION REPORT 50-528/95-23; 50-529/95-23:
50-530/95-23
Dear Mr. Stewart:
This refers to your letter of April 19.
1996, in which you provided supplemental information regarding your motor-operated valve program.
This information was requested in our letter of February 16, 1996,,
which forwarded NRC Inspection Report 50-528;529;530/95-23.
Specifically, you were requested to provide information concerning grouping of untested motor-operated valves.
the valve factors used in those groups, your trending activities, and the status of the open findings from your recent self-assessment of'our motor-operated valve program.
We have reviewed the additional information you provided and have found the information to be responsive to our request.
However, several comments regarding the adequacy of your justification for the grouping of untested valves within your program are discussed in the enclosure to this letter.
These comments were discussed with Mr. Scott Bower and other members of your staff during a telephone call on July 10.
1996.
As identified during the referenced inspection, we understand that you had scheduled completion of the final data reconciliation within your Generic Letter 89-10, "Safety-Related Motor-Oper ated Valve Testing and Surveillance,"
program by June 30, 1996.
You are encouraged to review your justification for the grouping of untested valves, in light of the comments provided in the enclosure, as part of your efforts to demonstrate the existing design basis capability for all valves in your program.
9b07170233 9b07i2 PDR ADQCK 05000528 6
Oj 1
i 4
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Arizona Public Service Company No additional information is required at this time.
We will review the adequacy of your Generic Letter 89-10 program in a future inspection.
Should you have any questions concerning this letter or its enclosure.
please contact Mr. Chris A. YanDenburgh of my staff at 817/860-8161.'incerely.
Dockets:
50-528 50-529 50-530 Licenses:
Enclosure:
As stated cc w/enclosure:
Mr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street
- Phoenix, Arizona 85007 Douglas K. Porter, Senior Counsel Southern California Edison Company Law Department, Generation Resources P.O.
Box 800
- Rosemead, Cali forni a 91770 Aubrey Y. Godwin, Director Arizona Radiation Regulatory Agency 4814 South 40 Street
- Phoenix, Arizona 85040 Chairman Maricopa County Board of Supervisors 111 South Third Avenue
- Phoenix, Arizona 85003 Angela K. Krainik, Manager Nuclear Licensing Arizona Public Service Company P.O.
Box 52034 Phoenix.
Arizona 85072-2034 homas P.
- Gwynn, D re or Division of React r afety
i I
0
Arizona Public Service Company John C. Horne, Vice President Power Supply Palo Verde Services 2025 N. Third Street, Suite 220
- Phoenix, Arizona 85004 Hr.
Roy P.
Lessy. Jr.
Akin, Gump, Strauss, Hauer 8 Feld, L.L.P 1333 New Hampshire
- Avenue, N.W.
Suite 400 Washington.
D.C.
20036
0
Arizona Public Service Company E-Hail report to D. Nelson (DJN)
E-Mail report to NRR Event Tracking System (IPAS)
E-Mail report to Michael Davis (HJDl) bcc to DMB (IE01) bcc distrib.
by RIV:
L. J.
Ca 1 1 an DRP Director Branch Chief (DRP/F, WCFO)
Senior Project Inspector (DRP/F, WCFO)
Branch Chief (DRP/TSS)
Leah Tremper (OC/LFOCB.
MS:
TWFN 9E10)
Resident Inspector ORS-PSB MIS System RIV File H.
Hammond (PAO, WCFO)
DOCUMENT NAME:
R:% PV'~PV523ak.cjm To receive copy of document, Indicate In box: "C" = Copy without enctosures "E" ~ Copy with enctosures "N" = No y
RIV:RI: EB RI: EB C:EB E
EHEB:NRR PBF:DRP D:ORS HFRunyan:1mb* CJMyers*
VanDenburgh*
RWessman*
DKirsch*
TPGwynn 06/28/96 revious y concurre 06/28/96 06/28/96 06/28/96 07/03/96
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Arizona Public Service Company E-Mail report to D. Nelson (DJN)
E-Hail report to NRR Event Tracking System (IPAS)
E-, Hail report to Michael Davis (MJD1) bcc to DMB (IE01) bcc distrib.
by RIV:
L. J. Callan DRP Director Branch Chief (DRP/F, WCFO)
Senior Project Inspector (DRP/F, WCFO)
Branch Chief (DRP/TSS)
Leah Tremper (OC/LFDCB.
MS:
TWFN 9E10)
Resident Inspector DRS-PSB MIS System RIV File H.
Hammond (PAO, WCFO)
DOCUMENT NAME:
R:N PVNPV523ak.cjm To receive copy of document,1ndicate in box: "C" = Copy without enciosures "E" = Copy with enciosures "N"= No y
RI: EB RIV:RI:EB HFRunyan:1mb* CJMyers*
06/28/96 06/28/96 revious y concurre C:EB E
VanDenburgh*
06/28/96 EMEB:NRR RWessman*
06/28/96 PBF:DRP DKirsch*
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ENCLOSURE SPECIFIC CONCERNS IN REVIEW OF PALO VERDE NUCLEAR GENERATING STATION GROUPING METHODOLOGY
Background:
NRC letter to Palo Verde Nuclear Generating Station, dated February 16,
- 1996, forwarded NRC Inspection Report 50-528/529/530/95-23.
The letter also
, requested additional information concerning the licensee's method of grouping untested motor-operated
- valves, the valve factors used in those groups, trending activities.
and the status of the open findings from the licensee's self-assessment of its motor-operated valve program.
Palo Verde Nuclear Generating Station provided the requested information in its letter dated April 19, 1996.
The licensee's supplemental information was reviewed by NRC to determine if those aspects of the licensee's motor-operated valve program were adequate for completion of the NRC review under Generic Letter 89-10.
"Safety-Related Motor-Operated Valve Testing and Surveillance."
This review identified that several concerns continue to exist with the licensee's method of grouping'alves.
Within the context of Generic Letter 89-10 'rouping is a method of validating the design basis capability of motor-operated valves which have not been dynamically tested within the licensee's Generic Letter 89-10 program.
Valve groups are established on the basis of expected similar dynamic performance.
Under these conditions, testing of some of the valves in the group can be reasonably expected to be representative of the performance for all of the valves in the group.
Widely differing dynamic performance has been displayed by apparently simi1ar valves.
Therefore, conservatism must be exercised in the development of groups in order to demonstrate the design basis capability of untested valves with assurance equivalent to that of differential pressure testing.
The following are comments resulting from NRC review of the additional information provided by the licensee.
Comments:
The initial grouping methodology (described as Method 1 in the licensee's response) appears to be consistent with the recommendations of Supplement 6 to Generic Letter 89-10 for grouping based on similar expected dynamic performance.
However, the expanded broader grouping (described as Method 2 in the licensee's response) appears to be based on available data rather than expected similar dynamic performance.
Specifically, the grouping of all valve sizes and pressure classes is not consistent with Supplement 6 and does not appear to be adequately justified.
Electric Power Research Institute (EPRI) data were used as available test data for establishing bounding valve factors for broader groups of untested valves.
This test data was intended for use in development of the EPRI Performance Prediction Methodology.
The use of this data in establishing bounding valve factors for untested groups of valves has not been adequately justified.
The Office of Nuclear Reactor Regulation has recently issued a safety evaluation report concerning the EPRI Performance Prediction Methodology.
The methodology incorporated a generic 1.05 multiplier to the predicted thrust for Borg-Warner valve factors in recognition of the unique test data on these valves.
EPRI data had reported Borg-Warner disc friction of 0.66, 0.61.
0.63, and 0.65.
These test results exceed the Method 2 group valve factor of 0.6 indicating that the grouping methodology may not be bounding in all cases.
The assigned valve factors for several groups do not bound all the test data for the groups.
For example.
the assigned close valve factor for Group 2 of 0.5 does not bound the EPRI in-situ test valve factor of 0.53.
Likewise, the assigned Group 6 valve factor of 0.55 does not bound the EPRI flow test valve factor of 0.6.
Group 7 was subdivided into two groups, Group 7a and 7b, on the basis of differential pressure conditions.
While the licensee stated that such grouping was indicated by its test data, no dynamic performance justification was provided for this grouping criteria.
Method 2 was not used as the basis for Group 8.
Rather'n additional grouping method, based on pressure
- class, was selectively combined with the Group 8 valves.
However, the resulting group valve factor was not applied to all the valves in the same pressure class group.
The grouping of all valves sizes within the same pressure class was not justified.
This combination of grouping methods does not appear to be adequately justified.
The licensee does not appear to have adequately incorporated FPRI flow test data.
EPRI determined thrust requirements that valves may eventually experience in their service due to valve factor'hanges.
The licensee's assumption that the numerical value for valve factor is equivalent to the disk friction coefficient reported by EPRI is only appropriate if the valves have significant margin that overrides the differences in these values.
e