ML20151X381
| ML20151X381 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, 05000000 |
| Issue date: | 11/01/1967 |
| From: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Peterson R PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML20151W779 | List:
|
| References | |
| FOIA-88-156 NUDOCS 8808250335 | |
| Download: ML20151X381 (3) | |
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UNITED STATES
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ATOMIC ENERGY COMMISSION
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NOV 1 1967 IN REPLv strta to Docket No. 50-275 Pacific Gas and Electric Company 245 Market Street San Francisco, California 94106 Attention:
'Mr. Richard H. Peterson Senior Vice President &
General Counsel Gentlemen:
This refers to your application for a construction permit and facility to be located at the Diablo Canyon license for a nuclear power plant The Advisory Committee on Reactor Safeguards indicated that site.
additional information would be required for the Committee to continue-Accordingly, a list of comments and questions from the its review.
Committee is attached.
The Committee has indicated that it may have additional questions, particularly on the thermal and hydraulic design aspects.
You are requested to provide the information requested as an amend-We shall be available to discuss and ment to your application.
clarify any of the aspects of the foregoing with you.
Sincerely yours, 4
l Peter A. Morris, Director l
Division of Reactor Licensing
Enclosure:
ACRS Ouestions cc:
Mr. J.
P. Stadelman testinghouse Atomic Power Division
' '. a. Box 355 Pittsburgh, Pennsylvania 15230 SEE ATTACHED SHEET FOR OTHER COSCURRENCES.
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8806250335 000721 PDR FOJA MCMILLADG-156 PDR
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ACRS QUESTIONS NUCLEAR POWER PLANT FOR THE DI ABLO CANYON SITE 1.
Provide more detailed studies on the question of xenon oscillations, including:
(a) The probability that undamped oscillations'may exist.
(b) What are the uncertainties in this estimate and what are their approximate magnitudes?
(c) What are the possible ways in which xenon oscillations could be worse than anticipated in magnitude and in their effect on the reactor?
(d) What are the requirements placed on reactor instrumentation by the xenon os,cillation problem? What assurance is availabic that these will be met?
(c) What other possible spatial perturbations in power might occur which should be coupled with xenen oscillations in evaluating control and instrumen,tation requirements?
2.
Provide a detailed discussion of heat removal from the core in the presence of failed fuel elements during a loss-of-coolant accident.
Include details on the mechanisms which are assumed to accomplish the necessary heat removal pripr to recovering the core. Show the degree of conservatism involved in f
i the' application of these mechanisms.
3.
The part length absorber cluster (PLAC). assemblies are moved under admin-istrative control and.would not result in exceeding the design limits on F and DNBR provided that (a) administrative 1y-imposed upper travel limits exceeded, and (b) rods are moved periodically (every 3 to S hrs) q are not and not left for as long as 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> without movement. If these provisions are violated, what are the consequences?
4.
For rodo that experience DNB (for example, see answer to Question V.B.4, pp. 60-63, Amendment No. 3), please indicate the ef fects on neighboring rods, including the consequences of flow instabilities. The answer-should cover two extremes - one with DNB yielding vapor blanketing and gross degradation of the heat transfer coefficient, and the other permitting operation beyond DNB.
Discuss in detail all possibic hositive reactivity effects which might be 5.
introduced by fuel motions during the various hypothesized accidents.
I I
i Evaluate the need and practicality of a seismic scram, 6.
Discuss the pros and' cons of one strong-motion accelerometer at the plant, versus two or three; consider the installation of accele 7.
near the plant.
Discuss the adequacy of steam generator isolation provisions under the assum tion that several tubes fail during postulated loss-of-coolant accidents.
8.
Discuss the adequacy of such isolation provisions under the assumption of large scale failure of the steam generator..
'pescribe the dicsci fuel storage and resupply pruvisions.
9,
. Describe the radiation protection provisions made in connection with the 10.
' control room ventilation system.
system spray nozzles of such design as to assure evidence is available concerning 11.
'Are the containment What
' performance at tated capacity?their per.formance if sodium thiosu l
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