ML100060791
| ML100060791 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/31/2009 |
| From: | Scherer A Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MA3543, TAC MA3544, TAC MA3545, TAC MA3546 | |
| Download: ML100060791 (3) | |
Text
SOUTHERN CALIFORNIA A. Edward Scherer Director FýlEDISON11 An EDISON INTERNATIONAL Company December 31, 2009 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Subject:
San Onofre Nuclear Generating Station Units 2 and 3 Docket Nos. 50-361 and 50-362 Notification of Intent to Permanently Remove Containment Hydrogen Recombiners - Train B
References:
See Enclosure
Dear Sir or Madam:
By Reference 1, the U. S. Nuclear Regulatory Commission (NRC) exempted San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 from certain requirements of the then-applicable regulation in 10 CFR 50.44. Among the exemptions granted was the elimination of containment hydrogen recombiners from the SONGS Units 2 and 3 design bases.
In Reference 2, Southern California Edison (SCE) stated our intentions regarding the hydrogen recombiners and other hydrogen control systems, upon NRC approval of our exemption request, as follows: "...it is currently Southern California Edison's intention to continue to maintain these systems to the extent that it remains prudent and practical... If at some future time equipment becomes inoperable and Southern California Edison decides to permanently cease repair efforts, Southern California Edison will then inform the NRC of that decision." NRC staff documented this commitment in the safety evaluation included in Reference 1. SCE further clarified our commitment in Reference 3.
In Reference 4, SCE provided notification of our intention to remove one of the two hydrogen recombiners (E146) per containment for the duration of the cycle 15 operating cycle of each unit. In Reference 5, SCE provided notification of our intention to extend removal of one of the two hydrogen recombiners (E146) per containment for an additional cycle (Cycle 16).
SCE has now determined that the space that has been vacated by removal of~the E146 Hydrogen Recombiners and supporting equipment could be better used for unrelated equipment. To that end, SCE is installing a Class 1 E 480 V Load Center on Unit 2 and intends to make similar changes to Unit 3. This Class 1 E 480 V Load Center provides a P.O. Box 128 San Clemente, CA 92674
Document Control Desk ',December 31, 2009 safety benefit of increased margin for the affected system. As a result, SCE will permanently leave the Units 2 and 3 Train B hydrogen recombiners removed from containment. The opposite train hydrogen recombiner (Train A) for each unit remains functional at this time and is being maintained on a frequency determined by SCE to be appropriate. SCE is maintaining the Train A hydrogen recombiner in each unit consistent with our original commitment.
If the staff should have any questions or require any additional information, please contact Ms. Linda Conklin at 949-368-9443.
Sincerely,
Enclosure:
cc:
E. E. Collins, NRC Region IV, Regional Administrator R. Hall, NRC Project Manager, San Onofre Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 and 3
Enclosure References
- 1) Letter from L. Raghavan (NRC) to H. B. Ray (SCE) dated September 3, 1999,
Subject:
Issuance of Exemption from Certain Requirements of 10 CFR 50.44 - San Onofre Nuclear Generating Station (SONGS), Units 2 and 3 (TAC Nos. MA3543, MA3544, MA3545 and MA3546)
- 2) Letter from D. E. Nunn (SCE) to Document Control Desk (NRC) dated July 19, 1999;
Subject:
Docket Nos. 50-361 and 50-362, Request for Exemption on Hydrogen Control, Proposed Technical Specification Change 496, San Onofre Nuclear Generating Station Units 2 and 3
- 3) Letter from D. E. Nunn (SCE) to Document Control Desk (NRC) dated October 29, 1999;
Subject:
Docket Nos. 50-361 and 50-362, Issuance of Exemption from Certain Requirements of 10CFR50.44, San Onofre Nuclear Generating Station, Units 2 and 3
- 4) Letter from A. E. Scherer (SCE) to Document Control Desk (NRC) dated February 5, 2007;
Subject:
San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362, Notification of Intent to Remove a Containment Hydrogen Recombiner
- 5) Letter from A. E. Scherer (SCE) to Document Control Desk (NRC) dated April 24, 2009;
Subject:
San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362, Notification of Intent to Extend Removal of the Containment Hydrogen Recombiners