ML16342A757
| ML16342A757 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 04/08/1999 |
| From: | Steven Bloom NRC (Affiliation Not Assigned) |
| To: | Rueger G PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML16342A758 | List: |
| References | |
| 50-275-96-21, 50-275-96-24, 50-323-96-21, 50-323-96-24, TAC-M99237, TAC-M99238, NUDOCS 9904130283 | |
| Download: ML16342A757 (8) | |
Text
~ w g~P,S RE@0
~o i
++*++
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 8, 1999 Mr. Gregory M. Rueger Senior Vice President and General Manager Pacific Gas and Electric Company, Diablo Canyon Nuclear Power Plant P.O. Box 3 Avila Beach, California 93424
SUBJECT:
DIABLOCANYON UNITS 1 AND 2 - EMERGENCY CORE COOLING SYSTEM AUTOMATICSWITCHOVER (TAC NOS. M99237 AND M99238)
Dear Mr. Rueger:
By letters dated April7, 1997, June 4, 1998, and March 11, 1999, Pacific Gas and Electric Company (PG8E) provided evaluation and basis for closure of an NRC concern regarding the emergency core cooling system (ECCS) manual and automatic switchover from the refueling water storage tank (RWST) to the containment sump for Diablo Canyon Power Plant (DCPP).
The NRC stated by letter to PG8E, dated May 7, 1980, that during post-LOCA conditions, manual switchover of the ECCS suction source for injection water from the RWST to the containment sump was acceptable, but requested the licensee more fullyautomate the switchover during the long term.
In addition, the staffs letter requested the licensee to submit a proposed conceptual design identifying each change necessary for further automation and committing to a schedule for submittal of a final design package for staff review within 120 days of receipt of the letter.
PGRE responded by letter dated May 28, 1980, stating that PG8E did not have sufficient information to conclude that such a change was either necessary or desirable, and that further evaluation of the safety implications of such a change was needed.
No further docketed, plant-specific correspondence occurred between PG&E and the staff until the issue was raised in NRC Inspection Reports 50-275;50-323/96-21, dated December 4, 1996, and 50-275;50-323/96-24, dated February 26, 1997. As a result of subsequent discussions between the licensee and the staff, the NRC and the licensee agreed that a resolution of the manual vs.
automatic switchover concern at DCPP should be formally documented for closure of the associated unresolved item (50-275;50-323/96021-07).
The licensee recently conducted additional evaluation and analysis, modified plant procedures and operator training, and concluded that manual action is an acceptable method for performing the ECCS switchover sequence.
c 9904L30283 990408 PDR ADQCK 05000275 p
PDR I~ RI," gEIRW C@PV u~'
~
~
~
,y
+WC4,'< i S j
Mr. Gregory M. Rueger April 8, 1999 The NRC staff has completed its review of this issue in regard to the manual actions by operators during the ECCS switchover sequence.
The enclosed safety evaluation provides the staffs review and conclusion that the licensee's use of manual ECCS swapover is an acceptable method.
Sincerely, teven D. Bloom, Project Manager, Section 2 Project Directorate IV 8 Decommissioning Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323
Enclosure:
Safety Evaluation cc w/encl: See next page
r
/
~t'
Mr. Gregory M. Rueger April 8, 1999 The NRC has completed its review of this issue in regard to the manual actions by operators during the ECCS switchover sequence.
The attached findings of the staffs review conclude that the licensee's use of manual ECCS swapover is an acceptable method.
Sincerely, ORIG.
SIGNED BY Steven D. Bloom, Project Manager Project Directorate IV-2 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323
Enclosure:
Safety Evaluation ccw/encl: See next page DISTRIBUTION Q'ooct.File j PUBLIC PDIV Reading JZwolinski/S Black S Richards S Bloom EPeyton OGC ACRS JCalvo RGallo KBrockman, RIV LSmith, RIV CNorsworthy (RCN) SE lI Document Name:
DC99237S.WPD OFC PDIV PDIV-2 PDIV-2/SC NAME SBI o Eeo SDembek DATE 4/
/99 4/W /99 4/
/9 OFFICIAL RECORD COPY
1 I
1'
Mr. Gregory M. Rueger CC:
NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. O. Box 369 Avila Beach, California 93424 Dr. Richard Ferguson, Energy Chair Sierra Club California 1100 11th Street, Suite 311 Sacramento, California 95814 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower 8 Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Christopher J. Warner, Esq.
Pacific Gas 8 Electric Company Post Office Box 7442 San Francisco, California 94120 Ms. Nancy Culver San Luis Obispo Mothers for Peace P. O. Box 164 Pismo Beach, California 93448 Chairman San I uis Obispo County Board of Supervisors Room 370 County Government Center San Luis Obispo, 'California 93408 Mr. Truman Burns Mr. Robert Kinosian California Public Utilities Commission 505 Van Ness, Room 4102 San Francisco, California 94102 Mr. David H. Oatley, Vice President Diablo Canyon Operations and Plant Manager Diablo Canyon Nuclear Power Plant P.O. Box 3 Avila Beach, California 93424 Telegram-Tribune ATTN: Managing Editor 1321 Johnson Avenue P.O. Box 112 San Luis Obispo, California 93406 Mr. Steve Hsu Radiologic Health Branch State Department of Health Services Post Office Box 942732 Sacramento, California 94232 Diablo Canyon Independent Safety Committee ATTN: Robert R. Wellington, Esq.
Legal Counsel 857 Cass Street, Suite D Monterey, California 93940
1