ML17325B080
| ML17325B080 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/27/1988 |
| From: | Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | Davis A NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| AEP:NRC:1084A, NUDOCS 8901030059 | |
| Download: ML17325B080 (6) | |
Text
gC C.EMOTED Dl BUTION DEMONSTR'N SYSTEM 1
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR-8901030059 DOC.DATE: 88/12/27 NOTARIZED:
NO DOCKET
-FACIL:50-315 Donald C.
Cook Nuclear Power Plant, Unit 1, Indiana 05000315 AUTH.NAME AUTHOR AFFILIATION ALEXICH,M.P.
(formerly Indiana 6 Michigan Ele RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Forwards addi info re operability of sys w/Copes-Vulcan valves,per NRC 881221 telcon.
DISTRIBUTION CODE:
A001D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal:
General Distribution NOTES RECIPIENT ID CODE/NAME PD3-1 LA STANG,J INTERNAL: ARM/DAF/LFMB NRR/DEST/CEB 8H NRR/DEST/MTB 9H NRR/DEST/SICB
~
NRR/PMAS/ILRB12 OGC/HDS1 RES/DSIR/EIB EXTERNAL LPDR NSIC COPIES LTTR ENCL 1
0 1
1 1
0 1
1 1
1 1
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1 1
1 RECIPIENT ID CODE/NAME PD3-1 PD NRR/DEST/ADS 7E NRR/DEST/ESB 8D NRR/DEST/RSB 8E NRR/DOEA/TSB 1 1 NUD
STRACT G F 01 NRC PDR COPIES LTTR ENCL 2
2 1
1 1
1 1
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1 R
I NOTE 'ro ALL "RIDS" RECIPIENIS.
PIZASE HELP US IO REDUCE WASTE!
CORI'AC1'lHE DOCXM'NT CON'IRDL DESK, ROOM Pl-37 (EXT. 20079)
KO ELIKBQTE KRR NAME FROM DISTRIBUTION LISTS H)R DOCtIMEMIS YOU DOINiT NEED)
TOTAL NUMBER OF COPIES REQUIRED:
LTTR 20 ENCL 17
Indiana Michigan Power Company P.O. Box 16631 Columbus, OH 43216 8
AEP:NRCr1084A Donald C.
Cook Nuclear Plant Unit 1 Docket No. 50-315 License No.
DPR-58 OPERABILITY OP SYSTEMS WITH COPES-VULCAN VALVES U.
S. Nuclear Regulatory Commission Docmnent Control Desk Washington, D.
C.
20555 Attn:
A. B. Davis December 27, 1988
Dear Mr. Davis:
A conference call was held among NRC Region III, NRR and AEPSC repres'entatives on December 21, 1988.
The purpose of the call was to address the basis for continued operation of Donald C.
Cook Nuclear Plant, Unit 1, due to concerns
'related to" the recent discrepancies found'n both weight and center of gravity of Copes-Vulcan air operated valves installed on small-bore diameter piping systems.
The enclosure to this letter provides the information requested during the conference call.
In addition, the plant walkdowns conducted to date and the preliminary analytical results have yielded no evidence that the systems affected by the valves are incapable of performing their safety related functions.
Initial computer runs on the first seventeen (17) valves indicate that we are within the NRC approved 2.0 Sy interim acceptance criteria.
As we have previously committed in our December 9,
1988 letter, we expect to complete our evaluation of the associated Problem Report regarding the subject valves by January 3,
1989.
This document has been prepared following Corporate procedures that incorporate a reasonable set of controls to ensure its accuracy and completeness prior to signature by the undersigned.
Sincerely,
<<pT I,
~
M. P. Alexich Vice President 890i03 g000P15 PDR ADOCK o FDC p
I~,
Mr. A. B. Davis AEP:NRC:1084A MPA/eh Attachment cc:
D. H. Williams, Jr.
W.
G. Smith, Jr.
- Bridgman R.
C. Callen G. Charnoff G. Bruchmann NRC Resident Inspector
- Bridgman
ATTACHMENT TO AEP'NRC:1084A Page 1
The following information provides the basis for our engineering judgment to continue operating Cook Nuclear Plant, Unit 1, while the analytical efforts continue regarding the impact of discrepancies found in both the weight and location of the center of gravity for installed small-bore (3/4", 1" and 2" diameter)
Copes-Vulcan air operated valves.
FUNCTION OF AFFECTED PiPING SYSTEMS The thirty-eight (38) fail closed Copes-Vulcan va'ives in Unit 1 are installed in piping systems that require no flow through to fulfilltheir safety related function but which must retain the pressure boundary integrity of the safety related systems to which they are connected.
Twenty-six (26) of these valves are normally closed during power operation and function as fill, drain, flush, and test lines for the ECCS and Accumulator systems.
Nine (9) of these valves are in the GVCS letdown system, which 'is isolated to maintain RCS inventory upon activation of the safety injection system.
The remaining three (3) valves, which automatically close on a safety injection signal, are in the line that continuously circulates the Boron Injection Tank contents during po~er operation.
As indicated in Chapter 2.5 of the Updated Final Safety Analysis
- Report, the Cook Nuclear Plant is located in the Michigan tectonic plate, historically a low seismicity basin.
The seismic history and known tectonics in the region reveal that no major earthquake epicenter has occurred within four hundred (400) miles of the Cook Nuclear Plant site and no shocks have occurred within fifty (50) miles of the Cook Nuclear Plant site of sufficient magnitude to cause significant structural damage.
Based on this historical
- data, the probability of a damaging earthquake at the Cook Nuclear Plant is considered to be extremely low.
SUPPORTS IN THE VICINITYOF THE VALVES Our Alternate Analysis criteria, the simplified approach to supporting small-bore (less than or equal to 2-inch nominal diameter) piping systems, required supporting of concentrated
- loads, such as valves'eview of available photographs has confirmed the existence of pipe supports in the vicinity of the valves.
ATTACHMENT TO AEP:NRC:1084A Page 2
STRENGTH OF PIPING Based on the inherent safety margins in the codes and our own power plant experience, piping systems are more robust than would be predicted by rigorous code analyses, Also, recent studies have indicated that piping system failures occur due to seismic anchor movements and not due to the seismic inertia loads.
Most of the piping systems in question are within the same building and are at the same general elevation.
Furthermore, the differential displacements under seismic conditions between the safety-related buildings are not significant; therefore, we believe that the piping systems that run through the containment to the auxiliary building would not be adversely affected in the unlikely event of a seismic disturbance.
OPERATING EXPERIENCE The affected piping systems have functioned for over twelve (12) years of operation in Unit 1.
During the recent walkdown to obtain as-built design information, the personnel involved were instructed to note any physical signs of distress in the piping system and supports.
No adverse findings were noted in the field walk of the accessible
- valves, demonstrating that the affected piping systems can withstand normal operating loads.