ML19256F959
| ML19256F959 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/07/1979 |
| From: | Gammill W Office of Nuclear Reactor Regulation |
| To: | Bryan S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| NUDOCS 7912270119 | |
| Download: ML19256F959 (1) | |
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December 7, 1979 Docket No. 50-368 MEMORANDUM FOR: Sam E. Bryan, Assistant Director for Field Coordination, Division of Reactor Operations Inspection, Office of Inspection & Enforcement FROM:
William P. Gammill, Acting Assistant Director for Operating Reactor Projects, Division of Operating Reactors, Office of Nuclear Reactor Regulation AN0MALY
SUBJECT:
ANO-2 CPC MODIFICATIONS TO ACCOMMODATE TH0T We have completed our review of the licensee's evaluation concerning the modification to the hot leg temperature measuring instrumentation to accommodate the anomalous hot leg temperature indications. We agree with the licensee's conclusions that the modification does not constitute an unreviewed safety question as defined in 10 CFR 50.59. However, we are continuing our review of the anomalous condition. By letter dated November 20, 1979, enclosed, we requested the development of certain action criteria in the start up and operating program. We plan to review the licensee's response and follow the start up operations.
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William P. Gammill, Acting Assistant Director for Operating Reactor Projects Division of Operating Reactors
Enclosure:
11/20/79 NRC ltr.
to AN0-2 cc:
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UNITED STATES E j y W, ',i NUCLEAR REGULATORY COMMISSION Enclosure
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Docket No. 50-368 Mr. William Cavanaugh, III Vice President, Generation and Construction Arkansas Power & Light Company P. O. Box 551 Little Rock, Arkansas 72203
Dear Mr. Cavanaugh:
During our meeting of October 4, 1979, regarding the hot leg temperature indication anomaly at Arkansas Nuclear One, Unit No. 2, you could not determine a firm cause for the anomaly.
Inspections were to be made of the reactor vessel internals and we understand the inspections have been com-pleted. We request your report on the results of those inspections.
We also understand that your evaluation under 10 CFR Part 50.59 relating to the modifications to the hot leg temperature system has now been completed.
We will review your evaluation to determine if further reviews are necessary before startup of ANO-2.
We consider this anomaly a condition of operation which is not fully under-stood. Therefore, we request particular attention to this in your startup and surveillance of operation.
In particular, we consider it important to monitor the temperature difference between temperature detectors in each hot leg during power ascension and to compare those differences with the experiences during the initial startup testing at the different power levels up to the 50 percent power level.
Beyond the 50 percent power level, the temperature differences should be monitored and compared with the expected temperature differences for the particular power levels. You should develop criteria of acceptance and action as it relates to continued power increase, continued operation and reporting to the NRC.
Further, continued surveillance of the temperature anomaly should be provided throughout the first cycle of operation. The surveillance should have criteria for acceptance and action as it relates to continued operation and reporting to the NRC.
Since much of the above relates to your startup testing, we request a summary of your startup testing program which would describe the above considerations and the action criteria relating to the verification of proper reassembly of the reactor and vessel. Also we request your proposed criteria for continued operation, power increase and reporting to the NRC as it relates to the anomaly.
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iir. William Cavanaugh, III Your inspection results and startup testing program ar.d action criteria relating to the hot leg temperature anomaly should be submitted in sufficient time to allow completion of our review prior to ascending aboie the 50 percent power level.
Sincerely, bk.
km Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors cc: See next page e
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