ML19320A564
| ML19320A564 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/16/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19320A563 | List: |
| References | |
| NUDOCS 8006250382 | |
| Download: ML19320A564 (2) | |
Text
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pa Krag'o UNITED STATES j
NUCLEAR REGULATORY CQMMISSION WASHING TON, D. C. 20555 p
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l
SUPPORTING CONTINUED OPERATION OF ARKANSAS NUCLEAR ONE, UNIT NO.1 WITH THE REACTOR VESSEL SURVEILLANCE PROGRAM CONDUCTED AT DAVIS-BESSE, UNIT NO. 1 By letter dated January 15, 1980, Arkansas Power and Light Company (AP&L),
the licensee of Arkansas Nuclear One, Unit No.1 (ANO-1) advised the NRC that the Davis-Besse, Unit No.1 (DB-1) had failed to maintain a cumulative reactor utilization factor of greater than 65% and provided justification for continued operation of ANO-1. The reason for this justification is that the reactor vessel surveillance specimens for ANO-1 are being irradiated in the DB-1 reactor vessel and Technical Specification (TS) 4.2.8 requires that if DB-1 at any time (beginning one year after DB-l's attainment of commercial operation at 100% power) falls to maintain a cumulative utilization factor of greater than 65%, the licensee shall submit a report to NRC justifying continued operation.
The date of comercial operation for DB-1 is November 20, 1977.
Between December 20, 1978 (one year after attainment of commercial operation at 100% power) and March 28, 1979 (THI-2 incident) DB-1 had a cumulative reactor utilization factor less than 65%. However, since the restart following the TMI-2 incident, DB-1 has maintained a reactor utilization factor considerably higher than 65%. Also, during this period, the operating history of DB-1 is very similar to ANO-1.
At the end of 345 EFP days of operation of AN0-1, capsule ANI-E was withdrawn from the ANO-1 vessel and the contents tested.
Based on the results of these tests, the ANO-1 pressure-temperature limits of the reactor coolant pressure boundary were modified and these limits are applicable through five EFP years of operation.
Currently ANO-1 has operated for about 3.5 EFP years. The second AN0-1 capsule has recently been removed during the current refueling outage from DB-1.
It is expec-ted to have received a fluence of 3.3 x 1018 n/cm.
From the results of tests of 2
these two ANO-1 capsules, we will be able to modify the ANO-1 pressure-temperature limits of the reactor coolant pres::ure boundary to be applicable through nine EFP years before the inspection date of the present limits.
Prior to nine EFP years another ANO-1 capsule will have been pulled from DB-1 to further extend our data base and update the pressure-temperature limits on the reactor coolant pressure boundary.
We consider that the relatively low utilization factor in the early life of DB-1 will not adversely affect the ANO-1 surveillance schedule.
We conclude, that since capsule ANI-B has now been removed from the DB-1 vessel and is being prepared for testing, that data from ANO-1 capsules will be available in time to provide a basis for updated pressure-temperature operating limits for AN0-1 prior to the expiration dates of the present limits.
8006250 3g
ANO-1 Based on the above, we find it acceptable to continue operation with the reactor vessel surveillance program conducted at D8-1.
However, to assure the continua-tion of an adequate reactor vessel surveillance program for ANO-1 with the utili-zation of the DB-1 reactor, we will request the licensee to propose TS which
. would provide limiting conditions of DB-1 operations for the irradiation of the third and remaining ANO-1 capsules in 'tne 08-1 vess~el.
Dated:
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