ML13331A514
| ML13331A514 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/07/1990 |
| From: | Ray H Southern California Edison Co |
| To: | |
| Shared Package | |
| ML13331A510 | List: |
| References | |
| NUDOCS 9011140078 | |
| Download: ML13331A514 (10) | |
Text
BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CALIFORNIA EDISON COMPANY and SAN DIEGO GAS & ELECTRIC COMPANY DOCKET NO. 50-206 for a Class 104(b) License to Acquire, Possess, and Use a Utilization Facility as Amendment No. 190 Part of Unit No. 1 of the San Onofre Nuclear Generating Station SOUTHERN CALIFORNIA EDISON COMPANY and SAN DIEGO GAS & ELECTRIC COMPANY, pursuant to 10CFR50.90, hereby submit Amendment Application No. 190.
This amendment consists of Proposed Change No. 234 to Provisional Operating License No. DPR-13. Proposed Change No. 234 is a request to revise the Provisional Operating License to allow a schedular extension for Item 5 (Overpressure Mitigation System) and Item 18 (Containment Venting) of the Cycle 11 Full Term Operating License.
In the event of conflict, the information in Amendment Application No. 190 supersedes the information previously submitted.
Based on the significant hazards analysis provided in the Description and Significant Hazards Consideration Analysis of Proposed Change No. 234, it is concluded that (1) the proposed change does not involve a significant hazards consideration as defined in 10 CFR 50.92, and (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change.
9011140078 901107 PDR ADOCK 05000206 P
PNU-
-2 Subscribed on this day of 747A~
"h68K/996, Respectfully submitted, SOUTHERN CALIFORNIA EDISON COMPANY By:
B:Har ld B. Ray Senior Vice Presidet Subscribed and sworn to before me this day of OFFICIAL SEAL
/
YOMAR V. CLEARY Notary Public-CalifomIa ORANGE COUNTY My Comm. Exp. May 8, 1992 No ry Public in andfoth S
e of California James A. Beoletto Attorney for Southern California Edison Company
DESCRIPTION AND SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS OF PROPOSED CHANGE NO. 234 TO PROVISIONAL OPERATING LICENSE NO. DPR-13 This is a request to revise the Provisional Operating License to allow a schedular extension for Items 5 and 18 of the Cycle 11 Full Term Operating License (FTOL) Projects.
DESCRIPTION OF CHANGE An Order Confirming Licensee Commitments on Full-Term Operating License Open Items was issued by the NRC on January 2, 1990 modifying our Provisional Operating License. The order incorporates the schedules for completion of the remaining FTOL items for Cycle 11 and Cycle 12.
The existing schedules for the RHR Overpressure Protection (Item 5) and Containment Venting (Item 18) projects may not be met during the Cycle 11 refueling outage. This proposed change requests the FTOL schedules for these two items be extended.
EXISTING CYCLE 11 FTOL SCHEDULE See Attachment 1 REVISED CYCLE 11 FTOL SCHEDULE A revised Cycle 11 FTOL schedule is provided as Attachment 2. The schedules for Items 5 and 18 have been extended to allow for NRC approval beyond the Cycle 11 outage.
DISCUSSION By letter dated October 2, 1989, we provided the NRC with the schedules for completing the remaining FTOL projects during Cycle 11 and Cycle 12.
These schedules were approved by the NRC and issued as an order modifying our license on January 2, 1990. The schedules for Cycle 11 Item No. 5, RHR Overpressure Protection as part of Overpressure Mitigating System (OMS), and Item No. 18, Containment Venting, require technical specification changes to be submitted to the NRC. Based on the schedule, the technical specification change for OMS would be approved by the NRC prior to the Cycle 11 refueling outage. The technical specification change for containment venting would be approved prior to the Cycle 11 refueling outage and implemented during the outage.
For OMS we have committed to provide revised technical specifications prior to restart.
For containment venting the NRC recently requested additional information. Since we have not yet provided the NRC with all the required information, it is not expected that these items will be approved prior to return to service. Therefore, it is necessary that the schedules be modified for these two items to indicate approval by the NRC after return to service.
The basis for the extension of the schedule is discussed below.
e 0 2
Item 5, OMS The amendment application revising the OMS related technical specifications was originally scheduled to be submitted by January 31, 1990. The review began in November 1989. A significant engineering effort has been required to reconstruct the design basis and the analyses to support the technical specifications.
This was discussed along with a revised schedule in our January 30, 1990 letter.
On March 30, 1990, we informed the NRC that a further schedule delay was necessary. This was due to the need to revise the calculation for the reactor vessel material adjusted reference temperature which could affect the heatup and cooldown curves, and information from Westinghouse which identified inconsistencies in the RHR system relief valve flow capacity. We were unable to assess the impact of the additional issues and could not determine a new submittal date at that time. We committed to provide a schedule by April 20, 1990.
Our letters of April 20, 1990 and June 1, 1990, provided the basis for delay of submittal of the OMS amendment application and advised the NRC of administrative controls implemented to ensure that the OMS will continue to perform its required functions. The June 1, 1990 letter states that an amendment application to revise all OMS related technical specifications will be submitted for NRC review prior to restart from the Cycle 11 refueling outage.
Based on item 5 of Attachment 1 to the NRC Order of January 2, 1990, the schedule for NRC approval of OMS related changes to the technical specifications is prior to the Cycle 11 refueling outage. To allow a reasonable amount of time for NRC review, it is requested that the schedule for the approval of the OMS related technical specification changes (item 5) be extended.
The administrative controls which are currently in place ensure that the OMS performs its required function. These controls adequately provide the required overpressure protection to the RCS and the RHR system during the low temperature operation of the plant. Therefore the requested schedular extension has no impact on the operation of OMS.
Item 18 - Containment Venting BACKGROUND In resolution of multi-plant action B-24, "Containment Venting and Purging,"
SCE committed to provide technical specification changes to incorporate a limitation on the opening angle of the containment ventilation isolation valves and to incorporate leak testing acceptance criteria for the containment ventilation isolation valves and the containment airlocks. Amendment Application No. 170, which was submitted on June 7, 1989, provided these changes.
In a letter dated February 22, 1990, the NRC required that Amendment Application No. 170 be revised to include Limiting Conditions for Operation
e S
3 (LCOs) to limit the amount of time the containment vent valves were left open.
The February 22, 1990 letter also required that administrative controls be placed in effect to limit the opening of the valves until the revised Amendment Application could be implemented.
The administrative controls were placed in effect shortly after receipt of the February 22, 1990 letter as described in our submittal dated March 29, 1990. A supplement to Amendment Application No. 170 to add LCOs for the containment ventilation isolation valves was submitted on May 3, 1990.
On October 12, 1990, during a telephone conversation with the NRC, additional information regarding the containment airlock testing was requested to support NRC review of this issue. An additional submittal will be required to provide the requested information.
The NRC's January 2, 1990 FTOL Order indicates this amendment is to be approved prior to the Cycle 11 outage and implemented during the outage.
Due to the schedule of the Cycle 11 outage and the request for additional information, approval and implementation of Amendment Application No. 170 and the supplement is not expected before the end of the Cycle 11 refueling outage. A description of the changes proposed by Amendment Application No.
170 and a discussion of the acceptability of the schedular extension is provided below.
AMENDMENT APPLICATION NO. 170 Amendment Application No. 170 and its Supplement make several changes to the technical specifications. The subjects addressed are:
o limitation of the opening angle for the containment ventilation isolation valves.
o leakage limits for penetrations subject to Local Leak Rate Testing (LLRT) at intervals of less than two years.
o reduction of the containment airlock test pressure from 10 psig to 3 psig.
o Limiting Conditions for Operation (LCOs) for the containment personnel airlock.
o LCOs to limit the amount of time the containment ventilation isolation valves are open during power operation.
The limitations on the opening angle for the containment ventilation isolation valves have been accomplished by installing a physical limiting device on the valves. The opening angle of the valves has been limited to an angle from which these valves have been demonstrated to be capable of closing under the differential pressure generated by a design basis accident. The revision to the technical specifications proposed by Amendment Application No. 170 will only update the containment isolation valve table and the Basis of Technical Specification 3.6.2 to note that the opening angle of these valves is limited.
The leakage limits for penetrations subject to an LLRT at intervals of less than two years, which are proposed by Amendment Application No. 170, will improve the Technical Specifications. These penetrations are used relatively
4 infrequently. By imposing more stringent leakage limits on these specific penetrations, degradation will be detected and corrected more quickly. The existing Technical Specifications limit the combined overall leakage of all penetrations subject to Type B testing and all containment isolation valves subject to Type C testing. This provision includes the penetrations in Amendment Application No. 170.
The changes proposed by Amendment Application No. 170 will not affect the existing combined overall leakage limits. Because the overall leakage rate will not be affected by Amendment Application No.
170, operation of the plant without Amendment Application No. 170 implemented will not create any additional hazards. The existing combined leakage limitation will control leakage to within acceptable, previously analyzed limits.
A reduction of the containment personnel airlock test pressure is also proposed by Amendment Application No. 170. The test pressure in the current Technical Specification is 10 psig. Amendment Application No. 170 proposes to reduce the test pressure to 3 psig on the grounds that a lower test pressure will provide sufficient indication of the sealing capability while minimizing stresses created at the door. Because the testing pressure proposed by Amendment Application No. 170 is less than that in the existing technical specifications, operation of the plant without this change in place will not create any additional hazards.
Amendment Application No. 170 also adds Limiting Conditions for Operation and ACTION statements for the containment personnel airlock which do not exist presently in the technical specifications. By incorporating these LCO's into the Technical Specifications, unnecessary plant shutdowns may be avoided.
Currently, when the plant is in operation and the leakage of an airlock is found to exceed the acceptance criteria, unit shutdown commences. The change proposed by Amendment Application No. 170 will allow operation to continue, under prescribed circumstances, with leakage exceeding the acceptance criteria limits while the airlock is repaired. The existing technical specifications are more conservative than those proposed by Amendment Application No. 170.
Finally, Amendment Application No. 170 adds LCOs to limit the amount of time the containment ventilation isolation valves are open during power operation.
Administrative controls have been placed in effect which limit the amount of time the valves can be open. These controls will remain in effect until the LCOs proposed by Amendment Application No. 170 are implemented.
Conclusion For the reasons discussed above, it is acceptable to reschedule implementation of Amendment Application No. 170 after the Cycle 11 refueling outage. The changes proposed by Amendment Application No. 170 are either more or equally conservative as compared to alternative measures presently in place in the technical specifications, or administrative controls are in place which duplicate the controls which will be implemented by Amendment Application No.
170.
5 SIGNIFICANT HAZARDS CONSIDERATION ANALYSIS As required by 10 CFR 50.91(a)(1), this change was evaluated and found not to:
- 1) involve a significant increase in the probability or consequences of an accident previously analyzed; or 2) create the possibility of a new or different kind of accident from any accident previously analyzed; or 3) involve a significant reduction in a margin of safety.
- 1. Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
RESPONSE: No Item 5, OMS The current schedule for NRC approval of the Overpressure Mitigating System (OMS) related technical specifications, as stated in item 5 of to the NRC Order, is prior to the Cycle 11 refueling outage.
SCE has committed to submit the amendment application to revise OMS related technical specifications to the NRC prior to restart from the Cycle 11 refueling outage. This proposed change extends the schedule for Item 5 to allow reasonable time for NRC review and approval of the OMS related changes.
The proposed schedular extension of the OMS technical specification changes does not impact the operation of the OMS, because currently implemented administrative controls ensure that the OMS will function as required. Therefore, the operation of the facility in accordance with this proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
Item 18, Containment Venting Amendment Application No. 170 and its Supplement address the following subjects:
o Limiting of the opening angle for the containment ventilation isolation valves.
o Leakage limits for penetrations subject to Local Leak Rate Testing (LLRT) at intervals of less than two years.
o Reduction of the containment personnel airlock test pressure from 10 psig to 3 psig.
o Limiting Conditions for Operation (LCOs) for the containment personnel airlock.
o LCOs to limit the amount of time the containment ventilation isolation valves are open during Modes 1, 2, 3, and 4.
6 The limitation on the opening angle for the containment ventilation isolation valves has been accomplished by installing devices on the valve which physically limit their opening angle. The revision to the Technical Specifications proposed by Amendment Application No. 170 will update the Technical Specifications to note that the valves have limiting devices.
The leakage limits for penetrations subject to an LLRT at intervals of less than two years, which are proposed by Amendment Application No. 170, will improve the Technical Specifications. These penetrations are used relatively infrequently. By imposing more stringent leakage limits on these specific penetrations, degradation will be detected and corrected more quickly. The existing Technical Specifications limit the combined overall leakage of all penetrations subject to Type B testing and all containment isolation valves subject to Type C testing. This provision includes the penetrations in Amendment Application No. 170. The changes proposed by Amendment Application No. 170 will not affect the existing combined overall leakage limits. Because the overall leakage rate will not be affected by Amendment Application No. 170, operation of the plant without Amendment Application No. 170 implemented will not create any additional hazards. The existing combined leakage limitation will control leakage to within acceptable, previously analyzed limits.
Amendment Application No. 170 also proposes a reduction in the containment airlock test pressure from 10 psig, which is currently in the technical specifications, to 3 psig. The test pressure in the existing technical specification is higher, and therefore inherently more conservative, than that proposed by Amendment Application No. 170.
The limiting conditions for operation regarding the containment personnel airlock which are proposed by Amendment Application No. 170 provide a limited time to allow repairs to be made to avoid unnecessary plant shutdowns. Presently, if excessive leakage is detected through the airlock, plant shutdown is initiated without allowing for a repair period.
The final change proposed by Amendment Application No. 170 will incorporate LCOs which limit the amount of time the containment ventilation isolation valves can be open during power operation. Opening of these valves during power operation is presently being limited through administrative controls. The administrative controls limit operation in the same manner as that proposed in Amendment Application No. 170.
The administrative controls will remain in effect until Amendment Application No. 170 is approved.
For the reasons stated in the discussions above, for each of the changes proposed by Amendment Application No. 170, operation of the facility in accordance with this proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
7
- 2.
Will operation of the facility in accordance with this change create the possibility of a new or different kind of accident from any accident previously evaluated?
RESPONSE: No Item 5, OMS The administrative controls currently implemented ensure that the OMS will provide adequate overpressure protection for the RCS and the RHR system. OMS related technical specification changes, once approved, will replace the administrative controls, and there will be no impact on the function of OMS. The schedular extension, discussed in item 1 above, has no impact on the operation of OMS. The current administrative controls ensure that OMS will continue to perform its safety functions.
Item 18, Containment Venting This proposed change reschedules approval of Amendment Application No.
170 to allow the plant to restart from the Cycle 11 refueling outage without Amendment Application No. 170 implemented. As discussed in the response to Question 1 above, each of the changes proposed by Amendment Application No. 170 is being conservatively controlled either through existing Technical Specifications or existing administrative controls.
Therefore, operation of the facility in accordance with this change does not create the possibility of a new or different kind of accident from any previously evaluated.
- 3.
Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
RESPONSE: No Item 5, OMS As stated above, the proposed schedular extension of Item 5 of to the NRC Order has no impact on the ability of OMS to perform its safety function, because the administrative controls currently implemented ensure satisfactory overpressure protection for both the RCS and the RHR system.
8 Item 18, Containment Venting This proposed change will reschedule approval and implementation of Amendment Application No. 170 until after Cycle 11.
As discussed in the response to Question 1, each of the changes proposed by Amendment Application No. 170 is currently being addressed in a conservative manner either by the existing technical specifications or by administrative controls.
Therefore, operation of the facility in accordance with this proposed change does not involve a significant reduction in a margin of safety.
SAFETY AND SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION Based on the preceding analysis, it is concluded:
(1) Proposed Change No. 234 does not involve a significant hazard consideration as defined by 10 CFR 50.92; and (2) there is a reasonable assurance that the health and safety of the public will not be endangered by the proposed change.
Attachments:
- 1) Existing FTOL Cycle 11 Schedule
- 2) Revised FTOL Cycle 11 Schedule