ML13326A897
| ML13326A897 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/01/1992 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9210080040 | |
| Download: ML13326A897 (3) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 R. M. ROSENELUM October 1, 1992 TELEPHONE MANAGER OF (714) 454-4505 NUCLEAR REGULATORY AFFAIRS U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Exemption Request from 10 CFR 50.54(o)
San Onofre Nuclear Generating Station, Unit 1 This is a request for an exemption from the leakrate testing requirements of 10 CFR 50.54(o).
This exemption will allow us to discontinue all leakrate testing requirements of Appendix J to 10 CFR 50 on the containment and systems penetrating the containment at San Onofre Nuclear Generating Station Unit 1 (SONGS 1).
SONGS 1 will be permanently shutdown and defueled following this fuel cycle which is forecast to end November 30, 1992. Maintaining containment integrity will no longer be necessary once we have shutdown Unit 1. Therefore, we request that this exemption be approved prior to shutdown to avoid incurring unnecessary expense, radiation exposure, or delay to our planned defueling schedule. We are requesting that this exemption become effective on December 1, 1992, since Unit 1 is scheduled to be in Mode 5 at that time.
REGULATORY REQUIREMENTS As specified by 50.54(o), requirements for containment leakrate testing are specified under Appendix J. The tests assure leakage will not exceed the allowable values specified in the Technical Specifications.
Exemptions from the requirements of 10 CFR 50 are provided for by 10 CFR 50.12 when special circumstances exist. The premature shutdown of SONGS 1 meets the special circumstances defined by 50.12(a)(1), (a)(2)(ii), and (a)(2)(iii), and is discussed under the "Basis for Exemption."
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Document Control Desk
-2 TECHNICAL JUSTIFICATION FOR EXEMPTION The Technical Specification requirements for leakage rate testing ensure that during operational periods, in the event of a design basis accident, containment integrity will not be compromised, and exposure will be well below 10 CFR 100 values. Containment integrity is not required below mode 3, when the reactivity condition is below 1% Ak/k and the reactor coolant system is below 500 psig, and is not required to be re-established in the permanently defueled condition.
Once SONGS 1 shuts down and reaches mode 5, the containment will be open in preparation for defueling operations. Radiological conditions within the containment following cessation of power operations, and during fuel transfer will not differ from those previously determined acceptable. Following shutdown and through defueling, when all fuel is removed from the reactor and placed in the spent fuel pool in a subcritical condition, SONGS 1 will not be capable of any credible design basis accidents associated with the reactor.
BASIS FOR EXEMPTION The basis for containment integrity is to mitigate the consequences of postulated accidents during reactor operations, including inadvertent criticality. Once we reach mode 5, those credible design basis accidents associated with reactor operations are not possible. Therefore, this condition provides the basis for an exemption from 10 CFR 50.54(o) and Appendix J.
The provisions of 10 CFR 50.12(a)(1), (a)(2)(ii), and (a)(2)(iii) specifically apply to this exemption request:
Authorization for exemption from 10 CFR 50.54(o) is authorized by law and has been granted to other utilities with similar circumstances. This exemption will not present an undue risk to the public health and safety with the permanent shutdown and defueling of Unit 1.
Application of 10 CFR 50.54(o) to a permanently defueled reactor that is incapable of any credible design basis accidents associated with the reactor would not serve the underlying purpose of the rule.
Document Gontrol Desk
-3 Pursuant to 10 CFR 50.12, SCE requests the NRC to approve this exemption request prior to the permanent shutdown of San Onofre Unit 1. We are scheduled to perform certain local leakrate testing by December 2, 1992.
If you have any questions or comments regarding this exemption request, please call me.
Very truly yours, cc:
J. B. Martin, Regional Administrator, NRC Region V George Kalman, NRC Senior Project Manager, San Onofre Unit 1 J. 0. Bradfute, NRC Project Manager, San Onofre Unit 1 C. W. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2&3 R. F. Dudley, Jr., Section Chief, Non-Power, Decommissioning, and Environmental Project, Directorate of Reactor Projects - 3, 4, and 5