ML18347A661
| ML18347A661 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 06/09/1976 |
| From: | Bixel D Consumers Power Co |
| To: | Purple R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML18347A661 (2) | |
Text
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R~gufatory Doclfee,.-i::;[I' /
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consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201
- Area Code 517 788-0550 June 9, 1976 DOCKET 50-255, LICENSE DPR-20 PALISADES PLANT -
MAIN STEAM ISOLATION VALVES This letter provides additional information in response to your letter dated May 6, 1975.
Your letter requested information concerning the performance of the Palisades main steam isolation valves under postulated accident con-ditions.
We previously responded to your request in our letter to you dated October 29, 1975.
Our letter of October 29, 1975 provided the results of our preliminary fluid dynamic and structural evaluation of the Palisades main steam isolation valves during the postulated main steam line break conditions.
This letter also described the design bases conditions for the postulated accident and indicated that based on the results of our preliminary evaluation we expected that the detailed analysis of the steam isolation valves which we had under way would demonstrate their adequacy.
We have now completed the fluid dynamic transient analysis of the valves when they are subjected to the design basis main steam line break conditions.
The disc center line closing velocity at the time of impact with the seat is calculated to be 81 feet per second.
This results in an impact energy of about two-thirds that which we reported to you in olir letter of October 29, 1975*
In addition, we have performed tests of the disc material which together with the structural analysis of the disc confirm that the disc will perform its function satis-factorily.
In addition to the above analyses of the valve disc which we have completed, we are presently performing structural analyses of the other valve internal parts such as the arm and post.
Preliminary results indicate that these parts are also satisfactory for the design basis main steam line break conditions described in our October 29, 1975 letter.
<OOSS
2 A summary report of the calculations and tests relating to the disc is in preparation and, along with final results of the valve internal parts, will be submitted about July 15, 1976.
David A. Bixel Assistant Nuclear Licensing Administrator CC:
JGKeppler, USNRC