ML20005A876
| ML20005A876 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 06/25/1981 |
| From: | Koch L ILLINOIS POWER CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0484, RTR-NUREG-484 NUDOCS 8107010422 | |
| Download: ML20005A876 (2) | |
Text
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4 ILLINDIS POWER 00MPANY W:.J 500 SOUTH 27TH STREET, DECATUR, ILLINOIS 62525 June 25, 1981 4
Mr. Harold Benton, Director v
Office of Nuclear Reactor Regulation
.pr h U.S.
Nuclear Regulatory Commission
(
h Washington, D.C.
20555 j\\^f Q}
/
Dear Mr. Denton:
Method of Combining Dynamic Responses for Mark III Piping and Equipment On April 14, 1981 several Mark III utilities and General Electric met with members of the NRC staff to discuss the subject program to justify the use of square-root-of-the-sum-of-the-squares (SRSS) method for combining dynamic responses of piping and equip-ment.
This Mark III SRSS pr^ gram is consistent with the NRC position on the use of SRSS as specified in Revision 1 of NUREG-0484,
" Methodology for C6mbining Dynamic Responses" and is also very similar tc the Mark II SRSS program which has been accepted by the NRC.
The Mark III SRSS program consists of calculating piping and equipment responses at numerous plant locations for several types of Mark III containment structural designs (i.e. free standing steel, concrete and concrete backed steel) and for several dynamic loads.
Using these responses, cumulative distribution functions will be calculated for several load combinations and the accepta-bility of SRSS will be evaluated using the NRC criteria specified in Revision 1 of NUREG-0484.
This comprehensive approach, together with the already approved use of SRSS specified in Revision 1 of NUREG-0484, is expected to demonstrate that the use of SRSS for combining dynamic LOCA, safety relief valve and earthquake responses is acceptable for all Mark III piping and equipment locations.
At the April 14 meehing, the NRC staff indicated that the pro-gram outlined by the Mark III utilities appeared to be an accept-able approach, assuming the results of the program are positive.
Since timely NRC acceptance of the SRSS method of combining Mark III piping and equipment responses is needed, it is essential that appropriate NRC resources be provided to review the results of this effo-t.
Initial information to start NRC staff review is planned to be available in October 1981 with a final report to be submitted to the NRC in November 1981 l
S If0 8107010D b
, ~ Harold Danton June 25, 1981 We need NRC review and acceptance of.this work as early as practicable.
We believe this should be_ achievable by December 1981 if appropriate resources are applied to this task in a timely manner.
We, therefore, request that you schedule such resources to achieve this objective.
Please advise if we can assist in any way or provide additional information.
Sincerely, L. J.
Koch Vice President cc:
S. N. Hou, NRC R. F. Bosnak, NRC e
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