ML20234D156
| ML20234D156 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Grand Gulf |
| Issue date: | 04/30/1974 |
| From: | Solbrig C AEROJET NUCLEAR CO. |
| To: | Mckinley J Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML20234A777 | List:
|
| References | |
| FOIA-87-40 NUDOCS 8707070116 | |
| Download: ML20234D156 (2) | |
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Mr. John C. McKinley Senior Staff Assistant Advisory Committee on Reactor Safeguards U. S. Atomic Energy Co= mission Washington, D.C.
20545 GRAND GULF NUCLEAR STATION UNITS 1 AND 2 - Cb'S-19-74 The following are my answers to the questions you asked in your letter of April 16, 1974:
1.
What uncertainties remain to be resolved for the Grand Gulf MARK III containment system with respect to your area of specialization?
(a) The analysis methods provided by G.E. appear to be inadequate, in gene ral.,
This applies to all of their containment and primary system analysis cnd not just the MARK III. For example, they use a very elementary primary system analysis. What experiments have been used to check the system effects of their primary system codes?
(b) The MARK III certainly appears to be an improved design over the previous designs.
(c) General Electric does not appear to do noding studies either in the analysis of the primary system or in the containment. Are they certain that the primary system analysis is conservative for containment analysis?
(d) Three dimensional effects should be included in the analysis.
It is possible that the jet from the break would be preferentially directed toward a portion of the vents and cause preferential flow out of these vents.
(e) Although it appears reasonable to assume that all the steam injected into the wet well condenses, it would be interesting to know what size bubble (as a function of temperature) released at a submergence of 10 ft. would not condense. Temperature effects are interesting to evaluate the effects of stratification.
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- l Mr. J. C. McKinley CWS-19-74 Page 2 (f) If the experiments which are to be run on MARK III produce some unexpected results, can the present design be modified to.take these into account? For example, it-seems that either increasing or decreasing the water level would be a worse situation than the present.
2.
Is the planned experimental program for MARK III adequate to resolve the uncertainties if the proposed design is used?
The ciperimental program appears to be good in many respects. The one question that it does not seem to answer is the three dimensional effect in the wet well.
3.
If not, what further work would you reco= mend be performed in order to eliminate significant uncertainties?
I would recom=end some tests or analysis aimed at showing that three dimen-sional effects are small.
4.
In view of your responses to questions 1, 2 and 3, do you believe the Grand Gulf containment system has sufficient probability of meeting its performance requirements to warrant proceeding with its construction?
Yes 5.
If you do not think the proposed system will perform adequately as presently designed, what modifications do you believe to be needed to make it adequate without further experimental work?
None 6.
If the containment is constructed,.rhat further work do you recommend be performed beyond that listed in 2 and 3 above?
None 7.
If you believe that construction should not proceed until further experimental information is available, what do you believe would be a reasonable period of time for obtaining the necessary information and what experimental or analytical information is needed before construction is permitted to begin?
Construction should proceed.
Y$ak U l
Charles W. Solbrig ds cc:
D. Okrent - ACRS T. G. Theofanous - Purdue Un.
H. D. Curet - ANC
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