ML20024F259
| ML20024F259 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 08/31/1983 |
| From: | Johnson G NRC OFFICE OF THE EXECUTIVE LEGAL DIRECTOR (OELD) |
| To: | Callihan D, Foster R, Kelley J Atomic Safety and Licensing Board Panel |
| References | |
| NUDOCS 8309090139 | |
| Download: ML20024F259 (1) | |
Text
August 31, 1983 James L. Kelley, Chairman Dr. Dixon Callihan Administrative Judge Administrative Judge Atomic Safety and Licensing Board Panel Union Carbide Corporation
- U.S. Nuclear Regulatory Commission P.O. Box Y Washington, D. C.
20555 Oak Ridge, Tennessee 37830 Dr. Richard F. Foster Administrative Judge P.O. Box 4263 Sunriver, Oregon 97702 In the Matter of DUKE POWER COMPANY, ET AL.
(Catawba Nuclear Station, Units 1 and 2)
Docket Nos. 50_413 and 50-414
Dear Administrative Judges:
During the conference call of August 31, 1983, Judge Foster asked whether the Staff has an ongoing technical study whose purpose is to improve the accuracy of prediction of changes in reference temperature. Counsel for the Staff agreed to forward this information, which is provided by Barry J. Elliot, a materials engineer in MTEB, and is as follows.
The precision of the prediction of the end-of-life reference temperature depends upon the standard deviation of the prediction model. The Staff's prediction model depends upon the amount of available reactor vessel material surveillance data. The reactor vessel material surveillance data is generated from test specimens which are placed inside commercial nuclear reactor vessels. These test specimens are placed in capsules and are withdrawn and tested in accordance with the requirements of Appendix H, 10 CFR 50. The results of the tests are forwarded to the Staff and are added to the data base for the prediction model. When sufficient new data becomes available, the Staff re-evaluates its prediction model.
It is expected that, as mcre data becomes available, the standard deviation will be reduced and the precision will be increased.
Thus, the Staff does have an ongoing program for improving its prediction of the change in reference temperature produced by neutron irradiation, the data for which is derived from the Appendix H reactor vessel surveillance program.
Sincerely, 83090o0139 830831 gDRADOCK05000$
George E. Johnson Counsel for NRC Staff cc: Service list OFC :
- 0E D V.
NAME :
nson:pl : G ay DATE:8/3/ /83 :8/ 3/ /83 :
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