ML19316B134
| ML19316B134 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/06/1980 |
| From: | Dunn C DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-12, TAC-42092, NUDOCS 8006110360 | |
| Download: ML19316B134 (4) | |
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June 6, 1980
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d United States Nuclear Regulatory Commission Office of Inspection and Enforcement Attn: Boyce H. Grier, Regional Director Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Reference:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 I.E.Bulletin 80-12
Dear Mr. Grier:
We have reviewed the referenced bulletin concerning Decay Heat Removal (DRR) System capability and the required actions with the following results.
1.
The review of the circumstances and sequence of events at Davis-Besse has been completed.
2.
A review of the following Licensee Event Reports (LERs) which describe lor of DER events at the Beaver Valley Power Station has been completed. LER 78-49, LER 79-18, LER 80-02, LER 80-22, LER 80-23 and LER 80-45.
I 3.
The Beaver Valley Power Station DHR system has two pumps each powered from a separate 4160 V emergency bus which is capable of being supplied by the emergency diesel generators. The DHR pump inlet valves are series isolation valves and the discharge valves are parallel isolation valves. The valves are powered from 480 V emergency buses with one inlet and discharge valve 4
on each bus. All four valves AUTO-CLOSE on a high pressure set-point signal, this provides a backup to the relief valve to prevent overpressurizing the DHR system. The instrumentation for the DHR system is all powered from vital buses. Diversity is provided by use of the steam generators when the reactor a
coolant loops are filled. The overall reliability of the DHR s.ystem during refueling and cold shutdown modes of operation has been good while the reactor coolant system is filled, but most q
losses of DHR at the Beaver Valley Power Station have been as a l
result of air binding of the pump while the reactor coolant loops have been drained to midpoint for maintenance or refuelina.
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/ll1 8006110360
B:cytr Vallcy Pow:r Sectica, Unit Ns. 1 q.
Docket No. 50-334, License No. DPR-66 I.E.Bulletin 50-12 Page 2 4.
Procedural guidance will be changed to ensure that either redundancy or diversity are maintaine.d to prevent loss of DHR and maintain decay heat removal of the reactor coolant system.
The procedure changes will be incorporated by station startup scheduled for July.
S.
The following Operating Manual procedures have been reviewed for adequacy of responding to loss of DER events.
Chapter 10, Residual Heat Removal System, Section 4A -
RHR System Startup Chapter 10, Residual Heat Removal System, Section 4I -
Cooldown to Mode 5 with RHR System Inoperable Chapter 10, Residual Heat Removal System, Section 4J -
RHR Operations When the RCS is Partially Drained Chapter 10, Residual' Heat Removal System, Section 4K -
Abnormal Procedure: Loss of RHR with RCS Drained to Mid-Span of Loops Chapter 51, Station Shutdown Procedures, Section 4D -
Cooldown from Hot Shutdown CMode 4) to the Cold Shutdown (Mode 5)
Chapter 53, Emergency Procedut es, Section 4E Loss of Residual Heat Removal System The review placed emphasis upon responses whe'n maintenance or refueling activities degraded the DHR Capability.
Changes to these procedures as a result of this review are described in Item 7.
6.a A Special Operating Order will be issued and approved prior to
&b the scheduled July plant startup to assure redundancy or diversity of the DHR systems during Modes 4, 5 and 6 unless prohibited by plant modification activity or required maintenance.
7.a The following' procedure changes have been or will be made as a result of the reviews performed for Items 4 and 5.
1.
Procedure 10.4K was changed in its entirety on 4-16-80 as a result of reviews conducted on the past incidents of loss of RHR flow during major maintenance outages.
2.
Procedure 53.4E-20 will be changed to incorporate'cooldown to Mode 5 without RHR.
- The change will be in effect by the schedule station startup.
3.
Proecedure Sl.4D has incorporated the disabling of Safety
' Injection, Containment Spray and inadvertent Containment Isolation Phase B.
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Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 I.E. Bulleitn 80-12 Page 3 7.a (continued) 4.
Station Shutdown procedures will be changed to disable auto-matic ECCS recirculation which is presently being installed at Beaver Valley Power Station. The changes will be in effect prior to the scheduled station startup.
7.b The plant has determined that the precautions instituted or planned to provide for diverse and redundant operation will adequately safeguard the facility against any degradation due to loss of RHR.
These precautions have been dealt with through procedures that address complete loss of RHR flow, decreasing RER pressure and loss of RHR flow when the reactor coolant system is partially drained.
The plant is presently looking into a method to constantly vent _..
the RHR system when the reactor coolant loops are drained to mid-span.
If you have any questions concerning this response, please contact my office.
Very truly yours,
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C. N. Dunn Vice President, Operations cc:
U.S. Nuclear Regulatory Commission Director Division of. Reactor Operations Inspection Office of Inspection and Enforcement Washington, D.C.
20555 Mr. D. A. Beckman, Resident Inspector U.S. Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, Pennsylvania 15077
> U.S. Nuclear Regulatory Commission c/o Document Management Branch Washington, D.C.
20555
i (CORPORATE SEAL)
Attest:
b^4 ocoru T.WelferpJr.'
Secretary COMMONWEALTH OF PENNSYLVANIA)
) SS:
COUNTY OF ALLEC42.ENY On this 6
day of 1980, before me, HENRY G. STOECKER a Nota g Public in and for said Commonwealth j
and County, personally appeared C. N. Dunn, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.
W HENRY G. STOECMER. NMary Public htbburgh. Megher'y County, Pa.
My Commission Expires february 20,1982
.