ML16341C290
| ML16341C290 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 03/21/1985 |
| From: | Knighton G Office of Nuclear Reactor Regulation |
| To: | Shiffer J PACIFIC GAS & ELECTRIC CO. |
| References | |
| TAC-51638, NUDOCS 8504050257 | |
| Download: ML16341C290 (10) | |
Text
Docket No.. 50-275
@gal / ~ IJ85 Mr. J. 0. Shiffer, Vice Pres ident Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Francisco, California 94106
Dear Mr. Shiffer:
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Subject:
Diablo Canyon Unit 1
Natural Circulation Boron Mixing Test The staff has completed its review of the PGIEE procedure for performing the natural circulation boron mixing test provided in your submittal of November 21, 1984.
Our evaluation is enclosed.
As a result of recent discussions with your staff, it is our understanding that certain con-siderations regarding the temperature recordings (magnetic head thermo-couples and upper head thermocouples) and post scram information will be included in the test procedure.
Based on this commitment, we find the test procedure appropriate for the natural circulation boron mixing test at Diablo Canyon Unit 1.
It is our understanding that this test is scheduled for the week of March 25, 1985.
A member of the staff plans to witness the test.
Sincerely,lg George W. Knighton, Chief Licensing Branch ¹3 Division of Licensing
Enclosure:
As stated cc w/enclosure:
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Mr. J.
D. Shiffer, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Fr ancisco, California 94106 Philip A. Crane, Jr.,
Esq.
Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 r.
Mr. Malcolm H. Furbush Vice President - General Counsel Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 Janice E. Kerr, Esq.
Califnrnia Public Utilities Commission 350 McAllister Street San Francisco, California 94102 Mr. Frederick Eissler, President Scenic Shoreline Preservation Conference, Inc.
4623 More Mesa Drive Santa Barbara, California 93105 Ms. Elizabeth Apfelberg 1415 Cozadero San Luis Obispo, California 93401 Mr. Gordon A. Silver Ms. Sandra A. Silver 1760 Alisal Street San Luis Obispo, California 93401 Harry M. Willis, Esq.
Seymour 5 Willis 601 California Street, Suite 2100 San Francisco, California 94108 Mr. Richard Hubbard MHB Technical Associates Suite K
1725 Hamilton Avenue San Jose, California 95125 Mr. John Marrs, Managing Editor San Luis Obis o Count Tele ram Tribune 1321 Johnson venue P. 0.
Box 112 San Luis Obispo, California 93406 Diablo Canyon Resident Inspector/Diablo Canyon NPS c/o US Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 93424 Ms.
Raye Fleming 1920 Mattie Road Shell Beach, California 93440 Joel
- Reynolds, Esq.
John R. Phillips, Esq.
Center for Law in the Public Interest 10951 West Pico Boulevard Third Floor Los Angeles, California 90064 Mr. Dick Blankenhurg Editor 5 Co-Publisher South County Publishing Companv P. 0.
Box 460
"'rroyo Grande, California 93420 Bruce Norton, Esq.
Norton, Burke, Berry 5 French, P.C.
202 E. Osborn Road P. 0.
Box 10569 Phoenix, Arizona 85064 Mr.
W.
C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburgh, Pennsylvania 15230 David F. Fleischaker, Esq.
P. 0.
Box 1178 Oklahoma City, Oklahoma 73101
Arthur C. Gehr, Esq.
Snell 5 Wilmer 3100 Valley Center Phoenix, Arizona 85073 Mr. Lee M. Gustafson, Director Federal Agency Relations Pacific Gas 5 Electric Company 1050 17th.Street, N.W.
Suite 1180 Washington, DC 20036 Regional Administrator - Region V.
US Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Michael J. Strumwasser, Esq.
Special Counsel to the Attorney General State of California 3580 Wilshire Boulevard, Suite 800 Los Angeles, California 90010 Mr. Tom Harris Sacremanto Bee 21st and 0 Streets Sacramento, California 95814 Mr. H. Daniel Nix California Energy Commission 1516 9th Street, MS 18 Sacramento,.California 95814 Lewis Shollenberger, Esq.
US Nuclear Regulatory Commission Region V
1450 Maria Lane Suite 210 Walnut Creek, California 94596 Mr. Thomas Devine Government Accountability Pro,iect Institute for Policy Studies 1901 gue Street, NW Washington, DC 20009
Staff Evaluation of Diablo Canyon Unit I Procedure Natural Circulation Boron Mixing Test ENCLOSURE The staff has completed its review of the Diablo Canyon Unit I Natural Circu-lation Boron Mixing Test Procedure No. 42.7, and the Pretest Report as discussed in licensee letters (J.
D. Shiffer, PGSE, to G.
W. Knighton, NRC),
dated October 26 and November 21,
- 1984, and February 25, 1985.
During the staff review of this information the licensee was requested to provide justification for (I) the use of the non-safety related volume control tank (VCT) instead of the safety related refueling water storage tank (RWST),
and (2) tripping the reactor coolant pumps (RCP) as late as 30 minutes after the reactor had been tripped.
The licensee provided the information in the February 25, 1985 submittal and in subsequent discussions with the staff.
In response to item (I), the licensee stated that the RWST water has a high level of dissolved oxygen.
If this water is injected in the reactor coolant system (RCS) while at hot conditions (above 200'F), it would cause excessive corrosion to take place at the nozzle connections to the RCS.
The licensee also stated that the use of the RWST would not provide significant additional information beyond that obtainable through the use of the VCT.
The staff concurs with this assessment.
'n response to item (2), the licensee stated that the RCP operation after reactor trip would enhance achieving stable conditions in the RCS (i.e.,
stabilize the RCS pressure, temperature, and pressurizer level, and steam generator levels and pressures),
and avoid subiecting the plant to a pressure rise transient that would follow a concurrent reactor trip and RCP trip.
The licensee stated that such a transient would be a dynamic simula-tion of a loss of flow accident that is not required to satisfy the criteria in the NRC Branch Technical Position, RSB 5-1.
The licensee also stated that RCP trip delay would not significantly affect RCS temperature distribution.
Since the staff's obiective is simulation of RCS temperatures, including those in the upper head reqion, the staff finds acceptable the continued operation of the RCPs until RCS stabilization has been achieved subject to the following changes in the procedures:
The recorder for the magnetic head thermocouples will be started prior to the reactor trip and will record at a rate appropriate.for the characteristics of the test.
2.
The recorder for the upper head'hermocouples will be started prior to the reactor trip and will record at a rate appropriate for the characteristics of the test until temperature stabilization is achieved.
The recorder will be restarted prior to the cooldown portion of the test.
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3.
Post-scram information recorded by the plant computer will he provided to the staff.
The licensee informed the staff that these changes will be included in the test procedures.
Based on the implementation of this commitment, the staff finds the test procedures, as revised, acceptable for the performance of the natural circulation boron mixing test.
The licensee has committed to submit a post-test report to demonstrate that the test satisfies the RSB 5-1 requirements.
That report will be reviewed by the staff to ascertain that cold shutdown can be achieved from the control room using only safety related equipment.
If a non-safety related component or system which was used during the tegt is found to be inadequate, the staff will require either upgrading of the component or system to safety-related or replacing it by another safety-related component or system.
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