ML13333A429
| ML13333A429 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/24/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | James Drake Southern California Edison Co |
| References | |
| TASK-15-12, TASK-RR NUDOCS 7911160100 | |
| Download: ML13333A429 (7) | |
Text
DISTPIRUTION RCPDR Local PDR ORR #2 Reading NRR Reading Docket No. 50-206 DEisenhut RHVollmer DLZiemann HSmith 0GOT 24 PWO'Connor DELD fMr. James H. Drake OCT 2 g
1979 OI&E (3)
Vice President DCrutchfield )2(
Southern California Edison Company JRBUchanan 2244 Walnut Grove Avenue TERA Post Office box b0o ACRS (16)
Rusemead, Califurnia 91770
Dear Mr. Drake,
RE.
SEP TOPIC XV-I2 Spectrum of Rod Ejection Accidents (PWR) iRadil ojgical Consequenices Enclosed is a copy of our draft evaluation of Systematic Evaluation Program Topic XV-12.
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 these topics that might affect the staff's evaluation.
Your response within 30 days of the date you receive this letter is requested.
If no response is received within that timie, we will assume that you have no comiments or corrections.
Sincerely,
.j Dn 1L. Ziemann, Chief Operating Reactors Branch h2 Division of Operating Reactors Encl osure.
Topic,V-12 cc w/enclosure See next page DOR:RB #2 D :
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 October 24, 1979 Docket No. 50-206 Mr. James H. Drake Vice President Southern California Edison Company 2244 Walnut Grove Avenue Post Office Box 800 Rosemead, California 91770
Dear Mr. Drake:
RE:
SEP TOPIC XV-12 Spectrum of Rod Ejection Accidents (PWR)
Radiological Consequences Enclosed is a copy of our draft evaluation of Systematic Evaluation Program Topic XV-12.
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 these topics that might affect the staff's evaluation.
Your response within 30 days of the date you receive this letter is requested. If no response is received within that time, we will assume that you have no comments or corrections.
Sincerely, Dennis L. Ziemann,,Chief Operating Reactors Branch '2 Division of Operating Reactors Enclosure.
Topic XV-12 cc w/enclosure:
See next paye
0 0
Mr. James October 24, 1979 cc w/enclosure:
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:
Richard Schaffstall 1747 Pennsylvania Avenue, N. W.
Suite 1050 Washington, D. C.
20006
San Onofre Unit 1 Topic XV-12 Spectrum of Rod Ejection Accidents (PWR) - 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 control rod ejection accident has been performed following the assumptions and procedures indicated in the Appendix to S. R. P. 15.4.8, "Radiological Consequences of Control Rod Ejection Accident (PWR)". The specific assumptions made regarding the plant conditions prior to the postulated accident and the expected responses are listed in Table XV-1.
In particular, it has been conservatively assumed that the accident is followed by a complete loss of offsite power. Therefore, the plant is cooled down by releasing secondary steam to the environment through the safety and relief valves. In addition, it has been assumed that prior to the accident the primary and secondary coolant activities were at the maximum levels allowed by the Technical Specifications 3.1.1 and 3.4.2.
The estimated site boundary doses resulting from this postulated accident (see Table XV-2) have been found to be within the 10 CFR Part 100 guidelines as specified in the Acceptance Criteria for S. R. P. 15.4.8.
On the basis of these results, we conclude that operation of the San Onofre Unit 1 Generating Station is safe with regard to a possible control rod ejection, and that the risk presented by this postulated accident is similar to that of plants licensed under current criteria.
October 24, 1979
TABLE XV-1 Assumptions Made in Analysis of the Radiological Consequences of Postulated Tube Failure, Main Steam Line Failure and Rod Ejection Accident
- 1. 103% of rated reactor power = 1387 Mwth.
- 2. Loss of offsite power following the accident.
- 3. Primary coolant activity prior to the accident of l.uCi/g of Dose Equivalent 1-131 and 100/E wCi/g of noble gases.
- 4.
Iodine spiking factor of 500 after the accident.
- 5.
Primary coolant activity of 60.,iCilg of Dose Equivalent 1-131 at time of accident for cases assuming a previous iodine spike.
- 6. Secondary coolant activity prior to the accident of 0.1 pCi/g Dose Equivalent 1-131.
- 7. Iodine decontamination factor of 10 between water and steam.
- 8. Meteorological conditions corresponding to a 30 meter elevated release with funigation and 1 /sec wjnd speed at a distance of 284 meters (X/Q = 1.1 x 10 sec/m ).*
- 9.
No additional fuel clad failures as a result of any of the accidents.
For the Steam Generator Tube Failure Accident
- 1. Failed steam generator is not isolated following the accident.
- 2. 50,000 lb. of primary coolant leak to the secondary side of the failed steam generator through the failed tube during the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (one half during the first 30 minutes).
- 3. All releases through the secondary side safety and relief valves.
For the Main Steam Line Failure Accident
- 1. Total primary.to secondary leak rateof1.1 gpm.
-2 For the Control Rod Ejection Accident
- 1. All releases through the secondary side safety and relief valves.
- 2. Total primary to secondary leak rate of 1. gpm.
- As per Regulatory Guide 1.5, "Assumptions Used for Evaluating The Potential Radiological Consequences of a Steam Line Break Accident for Boiling Water Reactors".
The 0-2 hour X/Q for a ground release is 9.5 x 10 sec/m based on the site meteorological data. Use of this X/Q would result in a reduction of about 10% in the calculated offsite doses.
TABLE XV-2 ACCIDENT DOSES AT NEAREST SITE BOUNDARY 2-hour Dose 2-hour Whole to the Thyroid Body Dose (rem)
(rem)
Tube Failure Accident
- 55.
0.6 Tube Failure Accident with 150.
0.6 Previous Iodine Spike*
Steam Line Failure Accident
- 15.
0.01 Steam Line Failure Accident
- 26.
0.01 with Previous Iodine Spike*
Rod Ejection Accident 1.4 0.01 Rod Ejection Accident with 2.4 0.01 Previous Iodine Spike*
- For this accident sequence it is assumed that an iodine spike was initiated some time before the accident resulting in the highest coolant activity allowed by the Technical Specifications.