ML19323A998
| ML19323A998 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 04/24/1980 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Berlinger C Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19323A999 | List: |
| References | |
| NUDOCS 8005090091 | |
| Download: ML19323A998 (2) | |
Text
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UNITED STATES 3 5.,
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'% V April 24, 1980
...e Dockets Hos. 50-368
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and 50-313 MEPORANDUM FOR: Carl Berlinger, Group Leader Operating Experience Evaluation Group i
FROM:
Robert W. Reid, Chief Operating Reactors Branch #4 l
Division of Operating Reactors
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SUBJECT:
AN0-1/2 RESPONSE TO LOSS OF 0FFSITE POWER OF APRIL 7, 1980 On April 7,1980, Arkansas Nuclear One, Units Nos. I and 2 automatically j
shutdown on loss of load. Both units were at 100% power at the time.
The plant experienced a total loss of offsite power and offsite power was not restored for approximately 25 minutes. The electrical load was picked up by emergency diesel generators.
The attached AP&L Transient Reports provide the details of the event and how the operators in the plants responded to the event.
The response of Unit No.1 is of primary concern.
You will note that the h
high pressure injection was manually initiated within 6 minutes after the g
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reactor trip and continued to operate for approximately 54 minutes. The l
operators apparently initiated HPI to increase pressure in the RCS because c,
!g of a decrease of pressure due to a sudden cooling as a result of an emergency feedwater pump operation. Also the PORV was manually openeo to help control A
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RCS pressure. Although the report did not indicate it, the block valve for
$y the PORV also was manually opened. This block valve was closed during operation 4
because of the action initiated to preclude an event similar to the Crystal River loss of NNI event.
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Our concern is focused on the operation of HPI, a safety system, and the E
manual operation of the PORY to control an operational transient. The m
question is why should a safety system be necessary to control an operational transient? Also,considering the effort that went into reducing the number of times the PORV is operated as a result of the TMI-2 accident, is it acceptable to use the PORV to control an operational transient?
Please review the event and determine if this is an acceptable mode of cperation and if it is not acceptable, recommend a course of action for ANO-1. Also determine the generic implicat' for other plants and recom: rend a course of action.
The TAC for this hem is 13145.
Please provide the evaluation and the recommendations in writing by May 30, 1980.
d.o Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors Actachment: AP&L Transient Report cc w/ attachment:
See next page
6 cc:
G. Lainas D. Eisenhut T. Novak C. Michaelson R. Vollmer B. Grimes G. Vissing R. Ingram W. Gamill L. Shao J. R. Miiler I