ML20137X656
| ML20137X656 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 01/16/1986 |
| From: | Freeman R NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Seyfrit K NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| Shared Package | |
| ML20137X661 | List: |
| References | |
| AEOD-E602, NUDOCS 8603110530 | |
| Download: ML20137X656 (2) | |
Text
JAN 161986 (D%
MEMORANDUM FOR:
Karl V. Seyfrit, Chief AE0D/E602 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data FROM:
Robert G. Freeman, Engineer Reactor Systems Section 2 Reactor Operations Analysis Branch Office -for Analysis and Evaluation of Operational Data
SUBJECT:
ENGINEERING EVALUATION REPORT: UNEXPECTED CRITICALITY DUE TO INCORRECT CALCULATION AND FAILURE TO FOLLOW PROCEDURES Enclosed is an AE0D Engineering Evaluation report on the Sununer-1 inadvertent criticality event for your consideration. The event was attributed to a number of causes. First, the licensed operator conducting the startup failed' to adhere to. applicable procedures in that criticality was not anticipated during control rod bank withdrawal and an awareness of plant conditions was not maintained at all times. Secondly, there was a lack of adequate guidance in the procedures used to calculate the estimated critical rod position (ECRF) and reference critical data (RCD) which resulted in a ECRP calculational error of 128 rod bank -steps.
Finally, there were procedural inadequacies in. the licensee's administration of the plant's on-the-job training progran which allowed an operator trainee to attenpt to perform a reactor startup without receiving the proper instruction in the basic skills and knowledge needed to accomplish this task.
Uncontrolled rod bank withdrawal from a subcritical core condition is an analyzed accident in Surmer's safety analysis report, and it is concluded that adequate core protection was maintained during this event. However, the Summer event and related operating experience have shown that licensee operator training programs may need to be reviewed in order to minimize the potential for prema-ture criticality events. An industrial organization has issued a report 9
i B603110530 860116 PDR ADOCK 05000395 S
PDR t
Karl'V. Seyfrit
- covering some of the recent premature criticality events. Thus, no further 1
action by this office is deemed necessary.
h/!tt.kh Robert G. Fr/ $ fxe%
eeman, Engineer Reactor Systems Section 2 Reactor Operatinns Analysis Branch Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
D. Burke, R II F. Jape, R II B. Boger, NRR J. Pellet,'R IV C. Rossi, IE Distribution PDR AE00 SF.
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