ML20064C362
| ML20064C362 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/01/1994 |
| From: | William Cahill, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M84072, TXX-94051, NUDOCS 9403090330 | |
| Download: ML20064C362 (3) | |
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- TXX-94051 File # 10010
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950 Ref.
- 10CFR50.12(a) 7UELECTRIC 10CFR50.55a(f)(4) l 2""NrI$'l, '
March 1, 1994 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 j
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SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 REQUEST FOR EXEMPTION FROM 10CFR50.55a(f)(4) FOR UNIT 1 INSERVICE TEST PROGRAM (TEST INTERVALS)
REF:
- 1) Appendix R of Supplement No. 26 to NUREG-0797, Related to the Operation of Comanche Peak Steam Electric Station, Unit 2 (February 1993)
- 2) HRC Letter from Suzanne C. Black to William J. Cahill, Jr.
dated January 29, 1993, " Safety Evaluation of the first l
ten-year interval inservice testing program for pumps and valves, Comanche Peak Steam Electric Station, Unit 1 (TAC NO. M84072)"
Gentlemen:
In Reference 1, the NRC stated that if TU Electric proposed to use the Unit 2 commercial operation date for establishing the 120-month interval for both units an exemption from the regulations is required.
Pursuant to 10CFR50.12(a), TU Electric requests an exemption from the requirement of 10CFR50.55a(f)(4) to allow the first periodic 120-month interval for the Unit 1 Inservice Test Plan to begin on the Unit 2 commercial operation date (August 3, 1993).
The first periodic interval for Unit 1 is currently based on the Unit I commercial operation date (August 13,1990).
10CFR50.55a(f) requires that IST programs be periodically updated at 120 month intervals (beginning with commercial operation of the unit) to the requirements of the latest edition and addenda of the ASME Code which are approved for use by the NRC staff twelve months prior to the start of the 120 month interval.
CPSES Unit 1 and Unit 2 began commercial operation approximately three years apart and are therefore on different schedules for periodic IST program updates.
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..TXX-94051 Page 2 of 3 NRC regulations provide for specific exemption in 10CFR50.12(a) if:
1)
The exemption is authorized by law; it will not present an undue risk to the public health and safety; it is consistent with the common defense and security; and-it is in the public interest.
2)
Special circumstances are present (e.g., application of the regulation would not serve or is not necessary to achieve its underlying purpose, or compliance would result in undue hardship or costs, or the exemption would result in~ safety benefits that compensate for any decrease in safety resulting from the exemption, or the exemption would provide only temporary relief.)
As discussed below, these elements are present in the requested exemption.
e j
As pointed out in the subject safety evaluations (References 1 and 2), it is-advantageous for a facility with two similar units to implement an IST program which is consistent between units by testing each unit to the same Code edition and.by scheduling 120 month program updates on each' unit to coincide.
CPSES Units 1 and.2 are similar units and TU Electric has therefore attempted to capture these advantages through the use of.one IST program which specifies the same test requirements for both units based on the same Code edition.
The advantages include a significant reduction in the administrative effort required in preparing periodic program updates, a corresponding reduction in the program review effort by the NRC staff and a reduction in the potential for personnel errors in the performance of testing requirements.
Further, a significant unit difference is eliminated.
by applying the same Code requirements to the testing of both units.
In order to maintain the consistency of the IST program between CPSES Units 1 and 2, TU Electric intends to perform future 120 month program updates for both units coincidentally.
TU Electric proposes to accomplish this by performing all future IST program updates for both units at 120 month intervals based on the Unit 2 commercial operation date.
This would effectively extend the first test interval for Unit i from 120 months to approximately 156 months which constitutes a deviation from the requirements of10CFR50.55a(f)(4). Therefore, TU Electric requests permission to perform future updates of the Unit 1 program in accordance with the 10CFR50.55a(f)(4) requirements for CPSES Unit 2 IST program updates.
This would result in a one-time only exemption for CPSES Unit 1.
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4 TXX-94051 Page 3 of 3 TU. Electric supports this request by noting that the CPSES Unit 1 IST program is currently meets the requirements of the 1989 edition of ASME Section XI.
Based on the CPSES Units 1 and 2 licensing-dates and the requirements of 10CFR50.55a(f)(4), the 1986 edition of ASME Section XI is the required code for the testing of pumps and valves in both units.
However, at TU Electric's request, the NRC staff granted permission to use the later approved 1989 edition of ASME Section XI for the interval of inservice testing at CPSES Unit 2 and at the same time granted permission to update the Unit 1 IST program to the use of that same Code.
(The'first interval inservice testing program at CPSES Unit I was originally approved based on the use of the 1986 edition of ASME Section XI.)
Effectively, the pumps and valves at CPSES Units 1 and 2 are being tested to the requirements of a later Code edition that might otherwise not be required to be implemented until the year 2000 for Unit 1 and the year 2003 for Unit 2.
The changes to the 1989 edition of ASME Section XI regarding pump and valve testing represent a substantial technical improvement over the 1986 edition not usually found from edition to cdition. TU Electric believes the early adoption of the 1989 edition for testing at CPSES Units 1 and 2 represents a safety benefit.
It should be emphasized that this exemption requests only applies to the timing of the update of the IST program for CPSES Unit 1.
TU Electric is not requesting an exemption from or deferral of any testing otherwise required by 10CFR50.55a.
If you have any questions.please contact Mr. Carl B. Corbin at (214) 812-8859.
Sincerely, William J. Cahill, Jr.
By:
A D. R. Woodlan Docket Licensing Manager c-Mr. L. J. Callan, Region IV Mr. Y. A. Yandell, Region IV Resident Inspectors, CPSES (2)
Mr. T. A. Bergman, NRR
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