ML19249A212
| ML19249A212 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/02/1979 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Morrissey J PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7908210342 | |
| Download: ML19249A212 (4) | |
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E WASHINGTON, D. C. 20555 AUG 2 1979 Docket Nos:
50-275 and 50-323 Mr. John C. Morrissey Vice President & General Counsel Pacific Gas & Electric Company 77 Beale Street San Francisco, California 94106
Dear Mr. Morrissey:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - DIABLO CANYON UNITS 1 & 2 Based on our evaluation of certain Westinghouse Corporation's reports, which you reference in your application, we find that additional information described in the enclosure to this 'etter will be required in order to continue our review.
Sincerely, a?
.. YY h*A John F. Stolz, Chief
, Light Water Reactors Branch No. 1 Division of Project Management
Enclosure:
Request for Additional Information cc:
See next page o
s 790821o397 841 010
ENCLOSURE REQU' UR ADDITIONAL INFORMATION 0, CANYON, UNITS 1 & 2 Dj NOS. 50-275 AND 50-323 1.
The single rod dr a DNB - limited transient considered to be a Condition 11 even-at is, a moderate frequency transient.
If a single rod drop e occurs when the reactor is in the automatic mode, the reactor contr(
-tem responds tc both the reactor power drop (mismatch between ine power and reactor power) and the decrease in the core averat mperature and attempts to restore both quantities to their original es. This restoration of reactor power by the reactor control sy:
mey result in some power overshoot depending upon the excore pot signal that is used.
Recent Westinghouse Corpora-tion (11) calculatia v ch model spr.t al effects have considered, among other things ifferent fuel cycles and times in fuel cycles.
Based on these cal-ations, W has proposed changes to the high negative flux rate trip set nts to assure that all dropped rod events result in a reactor trip.
he negative flux rate trip setpoint would be de-creased from 5 per-
.t to 3 percent and the rate-lag time constant would be decreased
- - ? reconds to 1 second.
It is requested that you revise your Tet icd Speci ficaitons, as appropriate, to resolve this matter.
231.1 The fission gas re' se mad-1 in the approved Westinghouse Fuel performance code (I
,.>10 tanyon Units 1 & 2, FSAR Section 4.2.4, Reference 3) has b found to underpredict pas release from fuel pellets at high bu 3, >20,000 mwd /tU.
The effects of higher fission gas release on the fety analyscs for Diablo Canyon 1 and 2 should be evaluated using ther (1) the approved performance code in com.
bination with the correction method described in NUREG-0418 or (2) a revised perft ante code which suitably models the increased fission gas releasr
, described in tqe approved version of WCAP-8720.
231.2 Westinghouse has d onted in WCAP-Ff 3 a change in the internal fuel rod gas pressure c
- ria.
Will the fuel design criterion for Diablo Canyon 1 and 2 inc
- rate this change for rod pressure?
If so, provide the critet us modified by NRC review, the above noted reference, and a r llysis in the FS P of hffected evaluations.
231.3 During a recent rr ling outage at a U plant (Salem 1), strap damage was observed on a -
aer of fuel spaca grids.
It is not known whether the damage occurr ur, 3 the initial core loading or during the refueling withdra Uhat assurancc
- n you provide that the same type of grid dame
.ill not be expen n ced at Diablo Canyon 1 and 27 n
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Mr. John C. Morrissey AUG 2 1979 11r. Jnhn C. Morrissey Mr. John Marrs Vice President & General Counsel Managing Editor Pacific Gas & Electric Company San Luis Obispo County 77 Beale Street Telegram - Tribune San francisco, California 94106 1321 Johnson Avenue P. O. Box 112 cc:
Philip A. Crane, Jr., Esq.
San Luis Obispo, California 93406 Pacific Gas & Electric Company 77 Beale Street Elizabeth S. Bowers, Esq., Chairman San Francisco, California 94106 Atomic Safety & Licensing Board U. S. Nuclear Regulatory Commission Janics
err, Esq.
Washington, D. C.
20555 Califcenir Public Utilities Commission 350 McAitister Street Mr. Glenn 0. Br'.,ht San Francisco, California 94102 Atomic Safety & Licensing Board U. S. Nuclear Regulatory Commission Mr. Frederick Eissler, President Washington, D. C.
20555 Scenic Shoreline Preservation Conference, Inc.
Tolbert Young 4623 More Mesa Drive P. O. Box 219 Santa Barbara, California 93105 Avila Beach, California 93424 Ms. Elizabeth E. Apfelberg Richard S. Salzman, Esq., Chairman 1415 Cazadero Atomic Safety & Licensing Appeal Board San Luis Obispo, California 93401 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Ms.
dra A. Silver 1792 ejo Avenue Dr. W. Reed Johnson San L.
Obispo, California 93401 Atonic Safety & Licensing Appeal Board U. S. Nuclear Renulatory Commission Mr. Gordon A. Silver Washington, D. C.
20555 1792 Conejo Avenue San Luis Obispo, California 93401 Alan S. Rosenthal, Esq.
Atomic Safety & Licensing Appeal Board Paul C. Valentine, Esq.
U. S. Nuclear Regulatory Commission 321 Lytton Avenue Washington, D. C.
20555 Palo Alto, California 94302 Ms. Raye Fleming Yale I. Jones, Esq.
1746 Chorro Street 19th Floor San Luis~Obispo, California 93401 100 Van Ness Avenue San Francisco, Calife.nia 94102 Brent Rushforth, Esq.
Center for Law in the Public Interest Mr. Richarri Hubbard 10203 Santa Monica Boulevard MHB Technical Associates Los Angeles, California 90067 1723 Hamilton Avenue Suite K Arthur C. Gehr, Esq.
San Jose, California 95125 Snell & Wilmer 3100 Valley Center Phoenix, Arizona 85073 c
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AUG 21979 Mr. John C. fiorrissey Mr. James 0. Schuyler, fluclea r Projects Engineer Pacific Gas & Electric Company 77 Beale Street San Francisco, California 94106 Bruce Norton, Esq.
3216 North 3rd Street Suite 202 Phoenix, Arizona 85012 Mr. W. C. Gangloff Westinghouse Electric Corporation P. C. Box 355 Pittsburgh, Pennsylvania 15230 Michael R. Klein. Esq.
Wilmer, Cutler & Pickering 1666 K Street, fl. W.
Washington, D. C.
20006 David F. Fleischaler, Esq.
1025 15th Street, ii. 4 5th Floor Washington, D. C.
20006 Dr. William E. Martin Senior Ecologist Battelle Memorial Institute Columbus, Ohio 43201
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