ML19211C499
| ML19211C499 | |
| Person / Time | |
|---|---|
| Issue date: | 10/03/1979 |
| From: | Cherny F Office of Nuclear Reactor Regulation |
| To: | Thadani A Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML18025B195 | List:
|
| References | |
| FOIA-80-587, REF-GTECI-A-09, REF-GTECI-SY, TASK-A-09, TASK-A-9, TASK-OR NUDOCS 8001110528 | |
| Download: ML19211C499 (2) | |
Text
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OCT 3 1979 NOTE T0:
A. Thadani FROM:
F. Cherny
SUBJECT:
INPUT TO MINUTES OF 09-27-79 AWS MEETING BETWEEN NRC, G.E., &
BWR OWNERS AND CP HOLDERS IN DENVER, COL.
Although the primary focus of this meeting was on SRV Load and Suppression Pool temperature calculation methodology; there were, as you know, several significant discussions regarding G.E.'s proposed methods for providing assurance of mechanical component structural integrity and/or operability if exposed to an ATWS event. The following key points discussed af the meeting that I feel should be covered in the minutes are:
1.
NRC (Cherny) pointed out that the questions attached to the February 15, 1979 Mattson letter specifically requested that BWR mechanical com-ponents be evaluated for all ATWS induced loads including SRV hydrodynamic loads. There was some verbal discussion at the August 10, 1979 meeting with G.E. in Bethesda with regard to how the ATWS induced SRV loads were being evaluated for components.
I noted that based on these verbal discussions, NRC understood that the effects of the SRV loads were being evaluated, however as yet, there was no discussion in writing about the effects of these loads on mechanical components, i.e., the May 1979 G.E. report only discusses these loads in terms of their effect on Containment.
2.
G.E. described verbally in somewhat greater detail than at the August 10 meeting, the rationale they propose to use in order to avoid determining specific stress levels resulting from ATWS - SRV hydrodynamic loads.
Using a less conservative methodology than that used to calculate SRV loads fro the MK I, II, and III Long Term Programs, G.E. has determined generic AWS SRV load vs. frequency forcing functions for each containment type.
G.E., based on work done to date, intends to show that the existing Design Basis SRV loads, calculated using a more conservative methodology for MK I, II, and III Long Term Programs, are larger in magnitude at all frequencies than the ATWS loads. Assuming this can be shown, G.E. will conclude that if structural integrity and operability has been demonstrated for the larger Design Basis Loads, they are also demonstrated for ATWS -
SRV loads.
1736 074 8001110 6 2 7
A. Thadani OCT 3 Ga 3.
NRC (Cherny) pointed out that even though the rationale per 2 above might be shown to be acceptable G.E. still has not considered the combination of the ATWS pressure with the AlVS - SRV load.
G.E. responded that it is their intention to demonstrate on a time history basis that the maximum ATWS pressure Nad cannot occur at the same time as the SRV hydrodynamic load. Cherny and Thadani of NRC expressed some doubt as to the feasibility of this approach.
G.E. comitted to submitting a draft of their position relative to the effects of SRV loads and the combination of the loads with the ATWS pressure load for NRC review prior to submittal of the December report.
4.
Comments were made by G.E. which seem to shed some doubt on the viability of the early generic verification program for BWR's.
G.E. stated that for MK I & II (BWR 3, 4, & 5's) plants they are encountering much difficulty in gathering information on the structural integrity and operability capabilities of BOP supplied mechanical components.
G.E. stated that at this time they did not foresee being able to address the plant specific details of such equipment in the BIN #2 December and March submittal s.
G.E. believes such equipment is best addressed by each Utility on a plant specific submittal basis.
E/Mm F. C. Cherny cc:
S.
.A
. Bosnak J. Knight N. Su K. Desai S. Hou H. Bramer B. D. Liaw 1736 075