ML20213E730
| ML20213E730 | |
| Person / Time | |
|---|---|
| Issue date: | 12/29/1983 |
| From: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20213E209 | List:
|
| References | |
| FOIA-87-113, FOIA-87-60 NUDOCS 8401310526 | |
| Download: ML20213E730 (2) | |
Text
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ATTACHMENT A UNITED STATES
"'*g NUCLEAR REGULATORY Commission WASHINGTON. D. C. 20655 December 29, 1983 MEMORANDUM FOR:
H. R. Denton, Director Office of Nuclear Reactor Regulation R. B. Minogue, Director X M
Office of Nuclear Regulatory Research FROM:
W. J. Dircks Executive Director for Operations
SUBJECT:
INTERACTION WITH IDCOR IN COMPARISON OF SEVERE ACCIDENT ANALYSIS The NRC is sponsoring a great deal of work to understand the behavior of light water reactors in severe accidents with a particular objective of reevaluating the severe accident source tenns.
Because of the regulatory significance of the source term reevaluation, we have established the policy that the NRC will take no final positions on the source term until the work is finished and has been subjected to adequate peer review.
The final step of that peer review is the special study by the American Physical Society (APS) of the scientific basis for source term estimation; this is the study reported in SECY-83-219A of November 4,1983.. I consider the APS study a prerequisite to completion of the NRC work.
The Industry Degraded Core group (IDCOR) has performed severe accident analysis during the past 2 years using experts, approaches, and methods Given the existence which in some areas differ from those used by the NRC.
l-of this substantial body of independent work, I believe that the NRC should use its staff and contractor resources to gain a better understanding of l
this body of technical information and compare it to the NRC-sponsored work in a systematic way. Timely and orderly completion of that comparison should add to the quality of the NRC-sponsored work.
Therefore, I recomend that you use the staff and contractor resources at your disposal to complete this effort in a timely and effective way.
I understand that you have scheduled a number of technical exchange meetings between IDCOR and NRC contractors and consultants for this purpose.
I I also understand that a list of technical issues has been prepared by NRC and IDCOR which constitutes a systematic catalogue of the severe accident work. This list is to be used as the matrix of comparison for the work by I
both parties through the identification and definition of the technical issue and a statement of position or conclusion regarding it.
These statements on
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2 technical issues can be used as you proceed with the IDCOR technical inter-actions in order to clearly identify areas of apparent consensus and issues Any conclusions reached are, of course, still in question or controversy.
I recognize tentative, pending the completion of the work and its review.
that the NRC staff will take positions on many of the technical issues-in the broad range of severe accident analysis but the staff should take no positions For example, I in areas which are a direct part of source term estimation.
do not consider accident sequence selection or containment performance analy-sis as a direct part of source tem estimation even though they are very important inputs to it.
One transport, and attenuation as a direct part of source term estimation.
l exception to this general rule is the review of the GESSAR II standard design With regard to the ongoing licensing review of GESSAR II, the application.
only standard plant application that will require severe accident findings during the period of the APS deliberations, the staff should estimate source This effort to complete the GESSAR II terms using the evolving methodolocy.
review in a timely manner is being made with the clear understanding by 4
GE that any changes in methodology resulting from the APS review or approaches which may be finally endorsed by the Comission, may require modification to the staff's severe accident evaluation.
By proceeding in this way I expect the staff to conduct this work in an orderly and timely way without prejudging the results of the APS study.
//
W. J. Dir Executive Director for Operations i
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