ML15237A336
| ML15237A336 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/02/2015 |
| From: | Dietrich A Plant Licensing Branch III |
| To: | Plant Licensing Branch III |
| Dietrich A | |
| References | |
| TAC MF6639 | |
| Download: ML15237A336 (3) | |
Text
September 2, 2015 MEMORANDUM TO: File FROM:
Allison W. Dietrich, Project Manager /RA/
Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
DONALD C. COOK NUCLEAR PLANT, UNIT 2 -
SUMMARY
OF TELEPHONE CONFERENCE ON AUGUST 24, 2015, TO AUTHORIZE VERBAL RELIEF FOR RELIEF REQUEST ISIR-4-06 (TAC NO. MF6639)
This memorandum summarizes the telephone discussion on August 24, 2015, between the U.S. Nuclear Regulatory Commission (NRC) staff and Indiana Michigan Power Company (I&M, the licensee) staff regarding the licensees relief request ISIR-4-06 for the Donald C. Cook Nuclear Plant (CNP), Unit 2. Participants in the discussion included Michael Scarpello, Helen Kish, et al. (I&M), and David Pelton, David Alley, John Tsao, and Terry Beltz (NRC).
By letter dated August 23, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15238A729), I&M submitted relief request ISIR-4-06 for the repair of degraded socket weld, FW-17, in the boric acid makeup system at CNP Unit 2. In ISIR-4-06, the licensee proposed to use the repair method in American Society of Mechanical Engineers (ASME) Code Case N-666 in lieu of using the requirements of the ASME Code,Section XI, to repair the subject socket weld. The NRC staff requested additional clarification in an e-mail to I&M staff dated August 23, 2015 (ADAMS Accession No. ML15236A314), and the licensee provided its response in a letter dated August 24, 2015 (ADAMS Accession No. ML15238A728).
ASME Code Case N-666 provides requirements on the application of a weld overlay on degraded socket welds, including welding procedures, design, evaluation, examination, and pressure testing. The licensee stated that it will follow all the requirements specified in Code Case N-666, except that the Code Case is applicable to degradation caused by vibration fatigue, whereas the degradation mechanism of the subject socket weld is a lack of fusion.
Although the subject socket weld is not degraded by vibration fatigue, the NRC staff finds that applying the weld overlay in accordance with N-666 will provide structural integrity and leak tightness to the degraded socket weld. The NRC staff also finds the licensees hardship justification acceptable.
The NRC staff determined that the proposed repair will provide reasonable assurance that the structural integrity and leak tightness of the repaired socket weld will be maintained until the next refueling outage, at which time the degraded weld is to be replaced.
The NRC staff finds that the proposed alternative in relief request ISIR-4-06 will provide reasonable assurance of the structural integrity and leak tightness of the subject socket weld.
The staff determines that complying with the specified ASME Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Accordingly, the staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(z)(2).
Based on the above, on August 24, 2015, the NRC authorized the use of relief request ISIR-4-06 at CNP Unit 2 until the next refueling outage, which is scheduled for October 2016.
All other requirements of ASME Code,Section XI, for which relief was not specifically requested and authorized by the NRC staff remain applicable, including the third party review by the Authorized Nuclear Inservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding subject relief request while preparing the subsequent written safety evaluation.
Docket No. 50-316 cc: Distribution via Listserv
ML15237A336 OFFICE DORL/LPL3-1/PM DORL/LPL3-1/LA DE/EPNB/BC DORL/LPL3-1/BC DORL/LPL3-1/PM NAME ADietrich MHenderson DAlley DPelton ADietrich DATE 8/26/2015 9/01/2015 9/02/2015 9/02/2015 9/02/2015