ML13333A368

Forwards Draft Evaluation of Systematic Evaluation Program Topic XV-19 Re LOCA Resulting from Spectrum of Postulated Piping Breaks within Reactor Coolant Pressure Boundary. Requests Input within 30 Days

ML13333A368
Person / Time
Site:	San Onofre
Issue date:	03/15/1979
From:	Ziemann D Office of Nuclear Reactor Regulation
To:	James Drake Southern California Edison Co
References
NUDOCS 7906040424
Download: ML13333A368 (5)

Text

DISTRIBUTION:

Docket(50-206)

NRC PDR DEisenhut Local PDR TERA MAR 1 5 1979 ORB#2 RDG JRBuchanan Docket No. 50-206 NRR RDG ACRS(16)

VStello DDavis BGrimes RVollmer Mr. James H. Drake OELD Vice President OI&E(3)

Southern California Edison Conpany

.DLZiemann 2244 Walnut Grove Avenue ABurger Post Office Box 800 HSmith Rosemead, California 91770

Dear Mr. Drake:

Enclosed is a copy of our draft evaluation of Systematic Evaluation Program Topic XV-19. You are requested to examine the facts upon which the staff has based its evaluation and respond either by confirming that the facts are correct, or by identifying any errors. If in error, please supply corrected information for the docket. We encourage you to supply for the docket any other material related to this topic that might affect the staff's evaluation.

Your response within 30 days of the date you receive this letteY is requested. If no response is received within that time, we will assume that you have no comments or corrections.

Sincerely, Original Signed by:

Dennis L. Ziemann Dennis L' Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors

Enclosure:

Topic XV-19 cc w/enclosure:

See next page 7906040YZY DO

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- 165 - 76

Mr. James H. Drake 2 -

March 15, 1979 cc Charles R. Kocher, Assistant General Counsel Southern California Edison Company Post Office Box 800 Rosemead, California 91770 David R. Pigott Samuel B. Casey Chickering & Gregory Three Embarcadero Center Twenty-Third Floor San Francisco, California 94111 Jack E. Thomas Harry B. Stoehr San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 U. S. Nuclear Regulatory Commission ATTN:

Robert J. Pate P. 0. Box 4167 San Clemente, California 92672 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676 K M C Inc.

ATTN:

Mr. Jack McEwen 1747 Pennsylvania Avenue, N. W.

Washington, D. C. 20006

San Onofre 1 Topic XV-19 Loss-of-Coolant Accidents Resulting from Spectrum of Postulated Piping Breaks Within the Reactor Coolant Pressure Boundary - Radiological Consequences The safety objective of this review is to assure that the releases from this postulated event will not result in exposures in excess of the established guidelines.

An analysis of the radiological consequences of a postulated loss-of coolant accident (LOCA) was performed in support of Amendment No. 25 to the Provisional Operating License issued on April 1, 1977. This analysis was performed following the assumptions and procedures indicated in the S.R.P. 15.6.5 and Regulatory Guide 1.4. The doses obtained from this review were within the 10 CFR Part 100 guidelines as specified in the acceptance criteria for the S.R.P. 15.6.5 (Revision 0).

Presently we estimate the doses to be even lower in view of the less restrictive dispersion coefficients established in Topic II-2.C,

• Atmospheric Dispersion". These doses, modified to reflect these updated X/Q values, are listed in Table XV-3. In addition, the total body doses calculated in 1977 included the contribution of both beta and gamma radiation, while current procedures consider only the effects of gamma radiation. As a result, the total body doses may be estimated to be about a factor of 2 lower.

On the basis of these results, we conclude that the radiological consequences of this postulated accident at the San Onofre Unit 1 plant are similar to those of plants licensed under current criteria.

References:

1. San Onofre Nuclear Generating Station Unit 1 -

FSAR.

Section 13.1

2. Safety Evaluation by the Office of Nuclear Reactor Regulation Supporting Amendment No. 25 to Provisional Operating License No. DPR-13 for the San Onofre Nuclear Generating Station, Unit 1. April 1, 1977.

9 TABLE XV-3 Estimated Offsite Doses For Postulated Loss of Coolant Accident Thyroid Total Body Dose Dose*

(rem)

(rem) 0-2 hour 150

8.

Exclusion Area Boundary 0-30 day

<70

<2.

Low Population Zone Include beta and gamma radiation.