ML13331A399
| ML13331A399 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/03/1990 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13331A400 | List: |
| References | |
| NUDOCS 9005070325 | |
| Download: ML13331A399 (9) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 HAROLD B.
RAY TELEPHONE VICE PRESIDENT 714-458-4400 May 3, 1990 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Supplement to Amendment Application No. 170 Containment Venting San Onofre Nuclear Generating Station Unit 1 A supplement to Amendment Application No. 170 to the Provisional Operating License DPR-13 is enclosed. We developed this supplement in response to your letter dated February 22, 1990 which requested us to add Limiting Conditions for Operation to our Technical Specifications which would limit the use of the containment ventilation isolation valves. Amendment Application No. 170 consists of Proposed Change No. 211 which requests a revision to the Appendix A, Technical Specifications, of Provisional Operating License DPR-13.
Proposed Change No. 211 (PCN-211), submitted on June 7, 1989, requested addition of leak testing acceptance criteria for the containment ventilation isolation valves and the personnel air locks to the Appendix A Technical Specifications.
PCN-211 also requested incorporation of Limiting Conditions for Operation for these components consistent with the Westinghouse Standard Technical Specifications.
BACKGROUND Your letter dated February 22, 1990, requested that we revise Amendment Application No. 170 to include Limiting Conditions for Operation (LCOs) which limit the amount of time the 6-inch containment vent valves may be open to a small fraction of the time that the plant is at power commensurate with safety related operational requirements. Your letter notes that our surveillance requirements for these valves may need to be revised as well.
You also requested that we close the 6-inch vent valves and provide a description of the administrative procedures placed in effect to maintain the 6-inch vent valves closed as much as practicable.
The valves were closed on February 27, 1990 and a procedure description was provided by our letter dated March 29, 1990.
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Document Control Desk May 3, 1990 DESCRIPTION The attached supplement to Amendment Application No. 170 is a request to incorporate LCOs for the 6-inch containment vent valves. The proposed LCOs require the 6 inch containment ventilation isolation valves to be closed as much as practicable during Modes 1, 2, 3, and 4. The valves may only be opened periodically for containment pressure control, for lowering the airborne radiation levels to satisfy ALARA requirements upon personnel entry, and for surveillance testing.
Since the 6-inch vent valves were closed on February 27, 1990, they have been opened periodically for pressure control.
Containment pressure slowly rises during normal operation due primarily to exhausted instrument air. When containment pressure approaches approximately 0.2 psig the vent valves are opened to allow the pressure to be lowered to approximately atmospheric.
Operating experience since the valves were closed shows that the valves must be opened for approximately 1-2 hours every 30-40 hours. The LCOs proposed by the attached supplement will allow this periodic venting practice to continue but will not allow continuous venting.
REVIEW OF TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENTS As requested in your February 22, 1990, letter, we have reviewed both our existing Technical Specifications and the Technical Specifications proposed by the enclosed amendment to determine if any surveillance changes would be required as a result of adding LCOs for the 6-inch ventilation valves. We compared our existing and proposed surveillance requirements to those suggested for the containment ventilation isolation valves by the Westinghouse Standard Technical Specifications (NUREG-0452). NUREG-0452 suggests that the containment ventilation isolation valves be surveilled for leakage, actuation, position, and accumulated annual time open. Our review has determined that our existing Technical Specifications combined with the Technical Specifications proposed by this amendment supplement adequately address surveillance of these valves as discussed below.
Section 4.3.1 of PCN-211 proposes surveillance testing standards which establish a maximum leak rate for the 6 inch containment ventilation isolation valves.
Leakage tests will be performed at least once every 3 months during operating Modes 1, 2, 3, and 4.
Surveillance of the automatic actuation of the containment ventilation valves is required by existing Technical Specification Section 4.3.2. Therefore, a change incorporating actuation surveillance is not necessary.
Our Technical Specifications do not require position verification of the valves to assure they are closed. The monthly surveillance of the position of the containment isolation valves suggested by the Westinghouse Standard Technical Specifications is not consistent with the handling of the San Onofre Unit 1 vent valves, since they are cycled approximately every other day for containment atmosphere pressure control.
Due to this frequent cycling, operators will detect if a valve is not closed by irregularities in the
Document Control Desk May 3, 1990 pressure readings and venting times. Since these valves will be surveilled for leakage and actuation, and are cycled frequently, the addition of a monthly valve position surveillance requirement to the Technical Specifications is not necessary.
Our Technical Specifications also do not require tracking the annual accumulated time open. The Westinghouse Standard Technical Specifications suggest imposing an annual limit on the amount of time that the containment ventilation isolation valves are allowed to be open and that the tracking of this amount be surveilled. This requirement is not consistent with the handling of the San Onofre Unit 1 vent valves since they are frequently cycled and the total venting time is not limited to a predetermined maximum number of hours.
If you have any questions in this matter, please let me know.
Respectfully submitted, By:
Haddld B. Ray Vice President Subscribed and sworn to before me this
\\3 day of
, 1990.
OFFICIAL SEAL YOMAR V. CLEARY Notary Public-CalIfomla ORANGE COUNTY No ry Public in the State
'My Comm. E. May 8.1992 o California Enclosure cc: J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of SOUTHERN CALIFORNIA
)
EDISON COMPANY and SAN DIEGO GAS &
)
Docket No. 50-206 ELECTRIC COMPANY (San Onofre Nuclear
)
Generating Station, Unit No. 1)
)
CERTIFICATE OF SERVICE I hereby certify that a copy of the Supplement to Amendment Application No. 170 was served on the following by deposit in the United States Mail, postage prepaid, on the 4 day of May, 1990.
Benjamin H. Vogler, Esq.
Staff Counsel U.S. Nuclear Regulatory Commission Washington, D.C. 20555 David R. Pigott, Esq.
Samuel B. Casey, Esq.
Orrick, Herrington & Sutcliffe 600 Montgomery Street San Francisco, California 94111 Charles W. Lacey Senior Vice President Bechtel Power Corporation 12440 East Imperial Highway Norwalk, California 90650 Michael L. Mellor, Esq.
Thelen, Marrin, Johnson & Bridges Two Embarcadero Center San Francisco, California 94111 Huey Johnson Secretary for Resources State of California 1416 Ninth Street Sacramento, California 95814 Janice E. Kerr, General Counsel California Public Utilities Commission 5066 State Building San Francisco, California 94102
-2 C. J. Craig Manager U.S. Nuclear Projects I ESSD Westinghouse Electric Corporation Post Office Box 355 Pittsburgh, Pennsylvania 15230 A. I. Gaede 23222 Cheswald Drive Laguna Niguel, California 92677 Frederick E. John, Executive Director California Public Utilities Commission 5050 State Building San Francisco, California 94102 Docketing and Service Section Office of the Secretary U.S. Nuclear Regulatory Commission Washington, D.C. 20555 J m'es A. Beoletto\\
DESCRIPTION OF SUPPLEMENTAL CHANGES TO PROPOSED CHANGE NO. 211 TO THE TECHNICAL SPECIFICATIONS PROVISIONAL OPERATING LICENSE NO. DPR-13 The following is a supplemental request to revise Section 4.3.1, "Containment Testing" and to incorporate three new sections; 3.6.4, "Containment Air Locks;" 3.6.5, "Containment Ventilation System Isolation Valves-Valve Leakage;" and 3.6.6, "Containment Ventilation System Isolation Valves-Valve Position;" and to remove our request in the original submittal of this proposed change to revise Section 3.6.2, "Containment Isolation Valves," into the Appendix A Technical Specifications for San Onofre Nuclear Generating Station Unit 1.
DESCRIPTION OF SUPPLEMENTAL CHANGE After Southern California Edison's (SCE) submittal of Proposed Change No. 211 (PCN-211), by letter dated June 7, 1989, the Nuclear Regulatory Commission (NRC) requested, by letter dated February 22, 1990, that SCE close the 6-inch containment ventilation isolation valves. The NRC also requested that SCE revise PCN-211 to include Limiting Conditions for Operation (LCOs) that limit the amount of time that the 6-inch containment vent valves are allowed to be open.
Proposed Section 3.6.6, "Containment Ventilation System Isolation Valves Valve Position," was added to incorporate LCOs which limit the amount of time the 6-inch containment vent valves are allowed to be open during Operating Modes 1, 2, 3, and 4. The proposed addition requires the vent valves to be closed as much as practicable. The valves will be allowed to be opened periodically for containment atmosphere pressure reduction. Containment pressure slowly increases primarily due to exhausted instrument air from normal operation. In order to keep the containment pressure below the 0.4 psig value specified in Technical Specification 3.6.1, periodic venting is required. Containment venting for pressure reduction is procedurally controlled and is started when pressure approaches approximately 0.2 psig and is stopped when the containment pressure is lowered to approximately atmospheric pressure.
The 6-inch containment vent valves are also allowed to be opened at the direction of the Senior Reactor Operator Operations Supervisor for surveillance testing and personnel entry. Surveillance testing requires that the valves be stroked (opened, then closed) to verify operability. When personnel entry into containment is required, the airborne radiation levels must be lowered to maintain ALARA conditions and the pressure must be maintained near atmospheric.
The provision to lock close the manual isolation valves CVS-301 and CVS-313 in order to maintain isolation in the containment purge supply and exhaust lines has been moved from Section 3.6.2, "Containment Isolation Valves;" to Section 3.6.6, "Containment Ventilation Isolation Valves-Valve Position." This change was made in order to be more consistent with the NUREG-0452, "Standard Technical Specifications for Westinghouse Pressurized Water Reactors."
-2 In addition, the reference to the SCE to NRC letter dated March 27, 1984 from M. 0. Medford to D. M. Crutchfield was moved from Section 3.6.2 to the proposed new Section 3.6.6. Also, reference to the NRC to SCE letter dated November 2, 1982 was included in the new proposed Section 3.6.6. This letter provides the NRC Safety Evaluation which discusses the analysis showing that the containment ventilation isolation valves are capable of closing in a design basis accident from an opening angle of up to 70 degrees.
Section 3.6.2, "Containment Isolation Valves," was revised in the original submittal of PCN-211. The section was being revised to add information about the opening angle limitation devices installed on the 6-inch containment ventilation isolation valves, CV-10 and CV-116. Because this supplemental submittal creates a new Technical Specification Section 3.6.6, dealing specifically with these valves, the information about the opening angle limitation has been moved to the new Technical Specification section.
Therefore, we are no longer requesting to revise Section 3.6.2.
PROPOSED TECHNICAL SPECIFICATIONS See Attachment 1.
SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS The proposed changes to PCN-211 made by this supplemental amendment do not change the significant hazard consideration analysis provided in Amendment Application No. 170. Amendment Application No. 170 revises two existing technical specification changes and adds two new technical specification sections. The two revised sections address containment isolation valves and containment testing. The two new sections add leakage limitations for the containment air locks and the containment ventilation system isolation valves.
Revising the two existing technical specifications and adding the two new technical specification sections improves the overall operational safety by further ensuring that the containment function of the containment structure remains operable.
This supplement provides changes that are consistent with Amendment 170. It adds the additional requirement to maintain the containment vent valves closed as much as practicable. As indicated in the November 2, 1984, NRC SER, Reference 2 of the proposed Technical Specification 3.6.6, provided an analysis that shows the valves will close when opened to an angle not exceeding 70*.
These valves have been modified to limit the opening angle to approximately 500.
This mechanical limitation along with the procedural limitation added by this supplement will ensure the valves will close or be closed when they are required to isolate containment.
Section 3.6.6 was added to incorporate Limiting Conditions for Operation which limit the amount of time the 6-inch containment ventilation valves are allowed to be open during Modes 1, 2, 3, and 4. The revision requires the valves to be closed as much as is practicable and only allows them to be opened for specific purposes (i.e., for periodic containment pressure reduction, for lowering containment airborne radiation levels and maintaining approximately
-3 neutral pressure during personnel entry into containment and for periodic surveillance testing).
Therefore, this change does not affect the significant hazards consideration previously provided with Amendment Application No. 170.
SAFETY AND SIGNIFICANT HAZARDS CONSIDERATION Based on the significant hazards consideration provided above and in Amendment Application No. 170, it is concluded that:
(1) the supplemental change to Proposed Change No. 211 does not involve a significant hazards consideration as defined by 10 CFR 50.92; and (2) there is reasonable assurance that the health and safety of the public will not ben endangered by the proposed change. - Supplemental Changes to Proposed Change No. 211 LNRC6.MTG2
ATTACHMENT 1 SUPPLEMENTAL CHANGES TO PROPOSED CHANGE NO. 211