ML20066B369
| ML20066B369 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/13/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20066B368 | List: |
| References | |
| NUDOCS 8211060587 | |
| Download: ML20066B369 (3) | |
Text
!(psnagk UNITED STATES NUCLEAR REGULATORY COMMISSION o
WASHINGTON, D. C. 20555 hl % l; SAFETY EVALUATION BY THE OFFICE OF NUGLEAR REACTOR REGULATION SUPPORTING AMENDMENT NOS. 79 AND 59 TO FACILITY OPERATI.NG LICEN.SES NOS. DPR-53 AND DPR-69.
BALTIM0RE GAS AND ELECTRIC COMPANY CALVERT CLIFFS NUCLEAR POWER PLANT UNIT NOS. 1 & 2 DOCKET NOS. 50-317 AND 50-318 Introduction By application for license amendment dated September 22, 1982, Baltimore Gas and Electric Company (BG&E) requested changes to Technical Specifica-tions (TS) for Calvert Cliffs Units 1 and 2.
The proposed changes to TS 4.6.4.1.4, " Containment Isolation Valves", would increase the interval for containment purge isolation valve testing from six (6) months to approximately eighteen (18) months.
In addition, a containment purge isolation valve seal replacement program would be incorporated in the TS.
Discussion On February 1,1982, the NRC issued Amendment Nos. 65 and 47 to the Oper-ating Licenses for Calvert Cliffs Units 1 and 2.
These amendments contained Limiting Conditions for Operation and Surveillance Requirements for the containment purge isolation valves. One such specification, TS 4.6.4.1.4, required the measurement of the leakage associated with the purge isolation valves at least once every six (6) months.
By application dated September 22, 1982, BG&E requested that the six month test requirement of TS 4.6.4.1.4 be replaced with a leakage test to be conducted,
... anytime upon entering MODE 5 from power operation modes, unless the last surveillance test has been performed within the past 6 months or anytime after being opened and prior to entering MODE 4 from shutdown modes..."
Since the only scheduled entering into MODE 5 (cold shutdown) is for refueling, the scheduled leakage test interval would correspond with the refueling interval which is expected to be 18 months for Calvert Since TS 3.6.1.7, "C'ntainment Purge System" Cliffs Units 1 and 2.
o
. requires the containment purge isolation valves to remain closed except in MODES 5 and 6 (cold shutdown and refueling modes, respectively), the scheduled interval for opening of these valves would also correspond with the refueling interval. As indicated in the application, this proposed 8211060587 821013 PDR ADOCK 05000317 P
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changeinthecontainmentpurgeisolationva5veleakagetestintervalwas the result of difficulty encountered by BG&E in performing these leakage tests as a result of the thermal gradient across the test boundary.
BG&E also indicated that testi.ng 1he containment purge isolation valves with the reactor shutdown would reduce the radiation exposure to personnel performing the leakage testing.
BG&E has also requested a change to the TS which would incorporate a containment purge isolation valve seal replacement program in the TS as new TS 4.6.4.1.5.
This program requires that,
"...The containment purge isolation valve seals shall be re-placed with new seals at a frequency to ensure that no individual seal remains in service greater than 2 consecutive fuel reload cycles. "
The September 22, 1982 applicationstatedthattheindividuaiseal replacement interval was selected based upon the seal vendor and BG&E experience. This experience indicates that the resilient seals as-sociated with the containment purge isolation valves can be expected to maintain a high degree of integrity for five (5) years of operation.
The proposed individual seal replacement interval of two refueling cycles corresponds to approximately three (3) years.
Evaluation In issuing Amendment Nos. 65 and 47, the NRC had been responding to the concern that the resilient seals of the purge isolation valves might degrade, causing eventyal leakage, even if these valves remained closed.
Such degradation was not observed at Calvert Cliffs.
In their Septem-ber 22,1982 application, BG8E presented an alternative to a six-month leak testing program for the containment purge isolation valves. This alternative consists'of:
o an eighteen-month leak testing program, and o a seal replacement program.
Experience to date at Calvert Cliffs has shown the purge isolation valve seals can satisfactorily perform their function for periods in excess of three years. Accordingly, we conclude that a three-year seal replace-ment program is sufficient to compensate for the decrease in seal reli-ability associated with increasing the leak test interval from six to eighteen months.
The changes to TS 4.6.4.1.4 and the addition of TS 4.6.4.1.5 do not decrease the reliability of the containment purge isolation valves and are therefore acceptable.
Environmental Consideration We have determined that the amendments do not authorize a. change in effluent types or total amounts nor an increase in power level and will not result in any si.gnificant environmental impact. Having made this determination, we have further concluded that the amendments involve an action which is insignificant from the standpoint of ~
environmental impact and, pursuant to 10 CFR @51.5(d)(4), that an environmental impact statement or negative declaration and environ-mental impact appraisal need not be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the probability or consequences of an accident previously evaluated, do not create the possibility of an accident of a type different from any evaluated previously, and do not involve a significant reduction in a margin of safety, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date: October 13, 1982 Principal Contributor:
D. H. Jaffe
.