ML16138A676
| ML16138A676 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/06/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML16138A675 | List: |
| References | |
| NUDOCS 8910170117 | |
| Download: ML16138A676 (5) | |
Text
Pk REG(o UNITED STATES 0
0 NUCLEAR REGULATORY COMMISSION C
WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 176 TO FACILITY OPERATING LICENSE DPR-38 AMENDMENT NO. 176TO FACILITY OPERATING LICENSE DPR-47 AMENDMENT NO. 173 TO FACILITY OPERATING LICENSE DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1. 2 AND 3 DOCKET NOS. 50-269, 50-270 AND 50-287
1.0 INTRODUCTION
By three letters dated September 29, 1989, and a letter dated October 4, 1989, Duke Power Company (the licensee) requested emergency Technical Specification (TS) amendments and temporary waivers of compliance to permit startup of Oconee Unit 1 and continued operation of Oconee Units 2 and 3. The proposals were necessitated by a failure to conduct required 10 CFR Part 50, Appendix J, testing of the containment isolation valves in penetrations 39 and 53.
The proposed TS change would add the requirement to perform Appendix 0 Type C local leak rate testing of the containment isolation valves in penetrations 39 and
- 53. Details of the background for the failure to perform the required tests, containment penetrations 39 and 53 configurations, and the proposed TS amendments and temporary waivers of compliance are provided in the licensee's letters cited above.
2.0 EVALUATION 2.1 Unit 1 For Unit 1, the licensee has already modified the system piping configuration to allow all of the penetration 53 containment isolation valves to be Appendix J Type C tested, and they have now been successfully Type C tested.
The NRC staff considers Type C testing of containment isolation valves to be a more accurate and more sensitive test than the test required by the existing plant TS which is to vent the system to the containment atmosphere during each Type A test and measure the valve leakages as part of the overall integrated leakage rate. Therefore, for this case, the staff considers the Type C tests, which have been conducted, to be an acceptable substitute for the test required by the TS. The valves which had niot been tested in penetration 39, IN-131 and ICA-29, were capable of being Type C tested because of their location outside containment and because the unit was shutdown. They have now been tested successfully. This satisfies the TS requirement for post-maintenance leakage rate testing, and these valves are considered operable. Further, the proposed amendments will continue to require the Type A testing currently required and 8910170117 891006 PDR ADOCK 05000269 P
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will add a requirement for periodic Type C testing.
This change provides an increase in the DEasures for ensuring containment integrity and is in compliance with the requirements of Appendix J. The proposed footnote 13 to the TS will allow these tests to commence at the next refueling outage, which is the normal schedule for such tests.
The NRC staff finds that the Type C testing, which has been performed for Unit 1, has, by its successful completion, demonstrated the operability of the containment isolation valves associated with penetrations 39 and 53. Therefore, it is acceptable for Unit 1 to startup and operate and for Type A and Type C testing to be conducted on normal schedules, with the next set of such tests to be conducted at the next refueling outage.
2.2 Units 2 and 3 These units are similar to Unit 1, except that Type C tests cannot presently be conducted on these operating units. Therefore, the leak-tight integrity of the untested containment isolation valves is uncertain. As a compensatory neasure, the licensee will close an additional manual valve in each of the four branch lines outside containment connected to penetration 53.
For Unit 2, penetration 39, only the containment isolation valve inside containment (2CF-44) has not received the required leak testing. The penetration has therefore been isolated by closing containment isolation valves outside containment, except in the nitrogen charging branch line.
Its containment isolation valve is a check valve (N-131) which by its nature cannot be positively closed, so a manual valve, N-130, isolates the line. For Unit 3, penetration 39, the only untested valve is N-131. Again, N-130 isolates the nitrogen charging branch and the other branches are isolated by their closed containment isolation valves, the same as for Unit 2. The licensee intends to keep these valves normally closed; however, the valves may occasionally be opened for short periods to allow the lines to be used, primarily to charge additional nitrogen into the "A" and "B" core flood tanks, as needed. While any one of these valves is open as described, a dedicated, qualified operator in constant communication with the control room will remain stationed near the valve so that it may be promptly closed if containment isolation is required.
The NRC staff finds the above compensatory measures to be adequate to assure containment integrity for the interim until proper Type C tests are conducted.
The interim periods as described in the proposed TS amendments are until January 15, 1990, for Unit 2, and until the end of the next refueling outage (scheduled to begin November 8, 1989) for Unit 3. Appendix J, Type A testing will be conducted during the next refueling outages for both Units 2 and 3.
The staff, therefore, finds that operation of Units 2 and 3 may continue under the conditions of the proposed TS anendments and the compensatory measures described above.
-3 3.0 EMERCENCY CIRCUMSTANCES The licensee's application for the TS change has been timely. On September 22, 1989, while reviewing the procedure for containment initegrated leak rate testing (CILRT) or, Oconee Unit 3, the licensee discovered a procedural error which would result in containment penetration 53 being improperly tested.
This same procedural error existed during all CILRTs oni Oconee Units 1, 2 and 3 conducted after 1982.
Prior to 1982, the system was configured differently and the proper system lineup for CILRT was established.
Because compliance with the TS had not been demonstrated, penetration 53 was required to be declared inoperable. In order to continue operating with an inoperable containment penetration, the licensee shut a manual valve in the line to this penetration, in accordance with TS 3.6.3.c.3, establishing isolation for this penetration.
However, the licensee is required to use this penetration intermittently to maintain a nitrogen charge on the A core flood tank. The licensee promptly contacted the NRC to request enforcement discretion, allowing them to unisolate and use penetration 53 when required to charge the A core flood tank. After discussions with the NRC, however, it was determined that a TS change would be appropriate for this situation. The licensee immediately requested the TS change by telephone and confirmed the call by letter the following day. Based on compensatory actions taken by the licensee, the NRC was assured that containment isolation would be available if required and granted a temporary waiver of compliance while the TS change was being processed.
As part of the corrective action for the failure to perform the proper testing of penetration 53, the licensee reviewed the status of all other penetrations similar in design to penetration 53.
On October 2, 1989, it was discovered that certain boundary valves for penetration 39 had been modified or replaced in Oconee Units 1, 2 and 3, and had not been leak rate tested as required after completion of the maintenance. The licensee promptly informed the NRC and implemented the same compensatory actions as for penetration 53. The licensee requested that penetration 39 be included in the proposed TS amendments by letter date October 4, 1989.
Because the licensee had committed to compensatory actions for the inoperability of penetration 39 which assured that containment isolation would be available when required, the NRC granted a second temporary waiver of compliance to allow the use of penetration 39 while the TS change was being processed.
The NRC staff finds that failure to grant the proposed changes in a timely manner would prevent startup of Oconee Unit 1 and result i, shutdown of Oconee Units 2 and 3. We also find that the licensee could not reasonably have avoided this situation, that the licensee has responded in a timely manner, and has not delayed its application to take advantage of the Emergency License Amendment provisions of 10 CFR 50.91.
Accordingly, the staff concludes that the licensee has satisfied the requirements of 10 CFR 50.91(a)(5), and that a valid emergency exists.
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4.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION The amendments would modify on an emergency basis the existing Oconee TS to specify when integrated leak rate testing (Type A) and local leak rate testing (Type C) of containment penetrations 39 and 53 is required. The current TS, in Table 4.4-1, only requires Type A testing for these penetrations. However, due to improper system alignment and failure to perform post-modification testing, penetrations 39 and 53 have not been tested as required. As a result, a literal reading of TS 3.6.2 required the licensee to declare these penetrations inoperable. In order to continue operating, the licensee isolated these penetrations by shutting nanual valves in the lines leading to these penetrations.
However, during plant operations, these penetrations must be utilized to charge the A and B core flood tanks. The proposed change would require additional testing of these penetrations to provide assurance that containment integrity was adequately maintained.
The Commission's regulations in 10CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards consideration, if operation of the facility, in accordance with the amendment would not:
(1) Involve a significant increase in the probability or consequences of any accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin or safety.
These amendments have been evaluated against the standards in 10CFR 50.92.
Each accident analysis addressed within the Oconee Nuclear Station Final Safety Analysis Report has been examined by the licensee with respect to changes proposed within this amendment request. The basis for testing penetrations 39 and 53 is to assure that containment integrity is available when required. The probability of any Design Basis Accident (DBA) is not affected by the proposed amendments since these penetrations are not considered to be an initiator for any DBA.
The proposed amendments constitute a more stringent testing requirement for penetrations 39 and 53 by specifying a Type C leak rate test, when such testing was not previously required. The operational use and design of the system is not changed by the amendments. Therefore, this change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
5 The proposed amendments constitute more stringent testing requirements by specifying Type C local leak rate testirig for penetrations 39 and 53. This testing will provide increased assurance thbt these penetrations will meet the required leak rate criteria during any accident requiring containment isolation.
As such, the change does not involve a significant reduction in a margin of safety.
On this basis, the Commission has determined that the amendments involve no significant-hazards consideration.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the State of South Carolina was contacted on October 2, 1989.
The state representative had no comments.
6.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements. The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or curulative occupational exposure. The FRC staff has made a final determination that the amendments involve no significant hazards consideration.
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessmert need be prepared in connection with the issuance of these amendments.
7.0 CONCLUSION
We have concluded, based on the considerations discussed above, that there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
J. Pulsipher L. Wiens Dated:
October 6, 1989