ML20072C937
| ML20072C937 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/18/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20072C934 | List: |
| References | |
| NUDOCS 8303100483 | |
| Download: ML20072C937 (3) | |
Text
l SAFETY EVALUATION AMENDMENTS 14 AND 3 TO NPF 10 AND -15 SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 & 3 DOCKET NO.
50-361/362 Introduction By letter dated February 11, 1983, the licensee requested, in part, a change in Technical Specification 3/4.7.5, Control Room Emergency Air CleanupSystem(CREACUS). The proposed changes are increases in the limit on ventilation unit flow rate from 1500 cfm + 10% to 2050 + 150 cfm, with corresponding changes in the pressure differential across the filters through which this flow is to pass. Our evaluation of the pro-posed changes and the associated Technical Specification modifications is given below. Both Units 2 and 3 share a comon control room pro-tected by CREACUS.
Evaluation In Supplement Number 2 to the San Onofre Unit 2 and 3 Safety Evaluation Report (NUREG-0712), the staff completed its review of control room habitabili ty. The review was conducted in accordance with Section 6.4 of the Standard Review Plan (NUREG-0800) and item III.D.3.4 of NUREG-0737, and there were no open items.
The licensee conducted tests of CREACUS as originally designed and i
constructed, and discovered that it was incapable of pressurizing the control room atmosphere to 1/8" water gauge relative to the outside atmosphere.
In a submittal dated January 27, 1982, the licensee pro-posed modifications to CREACUS to increase its capacity and to replace existing dampers on the nomal ventilation system ducts with low leakage 83031004EK3 830218 PDR ADOCK 05000361 P
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dampers. Following these and other modifications, the licensee again s
conducted tests of CREACUS, and found that the control room could be i
pressurized to 1/8" water gauge, but only by using higher air flows than allowed by the Technical Specifications.
The staff and the licensee met on February 26, 1983 in Bethesda to discuss the recent tests, possible further modifications, and the effect upon control room habitability during accidents of CREACUS's operation at higher air flows. The licensee presented its calculations of radia-tion doses in the control room following a postulated loss-of-coolant accident, and of chlorine concentrations in the control room following the postulated rel' ease of one ton of chlorine from an accident on the adjacent highway. The staff has reviewed the licensee's calculations and its own calculations as reported in NUREG-0712.
Using NUREG-0800, Section 6.4 procedures, the effects of increasing the CREACUS air flow were assessed. Calculated radiation doses remain less than the General Design Criteria (GDC) 19 guideline values and the chlorine analysis indicated acceptable concentration limits without taking credit for cleanup by the control room recirculation charcoal filters.
In addition, the licensee ag~ reed to continue efforts to reduce control room air leakage' presently occurring through' floor drains, and to assure that emergency procedures will contain measures to minimize leakage such that, should CREACUS ever be called upon to perform its functions, air flow would be less than the Technical Specification limit proposed.
Based on the above considerations, the staff concludes that the proposed changes to Technical Specification 3/4.7.5 is acceptable.
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,,y,
. Environmental Consideration The NRC staff has determined that these amendments do not authorize a change in effluent types or total amount nor an increase in power level and will not result in any significant environmental impact. Having made this deter-mination, we have further concluded that these amendments involve actions which are insignificant from the standpoint of ' environmental impact and pursuant to 10 CFR Section 51.5(d)(4), that an environmental impact statment or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of these amendments.
Conclusion Based upon our evaluation of the proposed changes to the San Onofre, Unit 2 and 3 Technical Specifications, we have concluded that:
(1) because these amendments do not involve a significant increase in the probability or consequences of accidents previously considered, do not create the possibility of an accident of a type different fron any evaluation previously, and do not involve a significant decrease in a safety margin, these amendments do not involve a significant safety hazards consideration; (2) there is reasonable assurance that the health and safety of the public will not be endangered by l
operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments Will' not be inimical to the common defense and security or to the health and safety of the public. We, therefore, conclude that the proposed changes are acceptable.
FEB 181983 l
Dated:
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