ML19274E694
| ML19274E694 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 04/11/1979 |
| From: | Darmitzel R GENERAL ELECTRIC CO. |
| To: | Stello V Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19274E695 | List: |
| References | |
| NUDOCS 7904170186 | |
| Download: ML19274E694 (3) | |
Text
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A GENER AL h ELECTRIC
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ENGINEERING GENERAL ELECTRIC COMPANY. P.O. box 460, PLEASANTON, CAllFORNIA 94566 DIVISION April 13,1979 Mr. Victcr Stello, Director Division of Operating Reactors Office of Nuclear Reactor Regulations U.S. Nuclear Regulatory Commission Washington, D. C.,
20555
Dear Mr. Stello:
Subject:
Probability Analysis of Surface Rupture Offset Beneath Reactor Building General Electric Test Reactor - License TR Docket 50-70 Attached is a probability analysis which was conducted as a result of a suggestion made at our meeting with the Nuclear Regulatory Comission (NRC) and its consultants on March 20, 1979.
The analysis was conducted to determine the likelihood of a surface rupture offset occurring beneath the General Electric Test Reactor (GETR) in any one year and thus to assess the need to include ground offset beneath the reactor as part of the design basis to which the structures and safety related equipment are evaluated. The probabilistic model was developed and included con-sideration of the observed data obtained from recent trench excavations.
The likeli-hood of an offset occurring beneath the reactor building was compared to the NRC criterion for not considering accident consequences.
This is defined to be approxi-mately 10-6 annual probability of occurrence.*
It is our position that the geologic input data are conservative as are all qualita-tive assum2tions used in the analytical model.
The calculated probabilities are less than 5x10-/ weighted average value and nearly a 90 percent confidence level of a 10-6 annual probability based on the most conservative assumptions.
It is the General Electric Company's position that based on these results, surface rupture offset occurring beneath the GETR should not be considered as a design basis event.
Previously submitted documents which have described modifications being made to the GETR and structural analysis of the concrete structure and safety related equipment provide assurance that the reactor could sustain a 3 foot surface offset.
It is our intention to complete these modifications even though this probability analysis shows that no offset need be considered. This probability analysis thus provides additional assurance that the GETR can operate withnut endangering the health and safety of the public.
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GENERAL @ ELECTRIC Mr. Victor Stello, Director Division of Operating Reactors April 13, 1979 The General Electric Company requests that this analysis be reviewed and that the Safety Evaluation Report be completed in accordance with the previously committed schedule ** of 60 days after receipt of the final Geological Investigation - Phase II, General Electric Test Reactor Site, Vallecitos, California which was delivered on March 1, 1979.
We also request that the Advisory Coumittee on Reactor Safeguards review be scheduled at the earliest possible opportunity.
Very truly yours,
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R. W. Darmitzel Manager Irradiation Processing Operation vcc
Attachment:
Probavility Analysis of Surface Rupture Offset Beneath Reactor Building, General Electric Test Reactor - EDAC-117-217.13
- USNRC, " Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants", LWR Edition, September 1975 - Section 2.2.3
- Letter Robert W. Reid, Chief Operating Reactors Branch #4, Division of Operating Reactors to R. W. Darmitzel dated September 27, 1978
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GENER AL [$ ELECTRIC AFFIRMATION The General Electric Company hereby submits a Probability Analysis of Surface Rupture Offset Beneath Reactor Building, General Electric Test Reactor, License TR-1, Docket 50-70.
To the best of my knowledge and belief, the information contained herein is accurate.
By: N@[
R. W. Darmitzel, Manager
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Submitted and sworn before me this thirteenth day of April,1979.
Nenmw 8dra<ha
. Notary Public in and for the County of Alameda, State of Califor#bia.