ML20134C037

Provides Review of 850701 Submittal Re Insp Plan of Reactor Coolant Stainless Steel Piping During 1985 Refueling Outage. Insp Plan Proposed by Licensee Satisfactory.Listed Comments Based on Results of Insps,Per Generic Ltr 84-11

ML20134C037
Person / Time
Site:	Millstone
Issue date:	08/14/1985
From:	Zwolinski J Office of Nuclear Reactor Regulation
To:	Opeka J NORTHEAST NUCLEAR ENERGY CO.
References
GL-84-11, LSO5-85-08-018, LSO5-85-8-18, NUDOCS 8508160183
Download: ML20134C037 (3)

Text

k UNITED STATES NUCLEAR REGULATORY COMMISSION

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WASHINGTON, D. C. 20555

'+g # August 14, 1985 Docket No. 50-245 LS05-85-08-018 Mr. John F. Opeka, Senior Vice President Nuclear Engineering and Operations Northeast Nuclear Energy Company Post Office Box 270 Hartford, Connecticut 06141-0270

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SUBJECT:

PIPING INSPECTION PLAN t

, Re: Millstone Nuclear Power Station, Unit No. 1 The staff has reviewed the submittal dated July 1, 1985 from Portheast Nuclear Energy Company (NNECO) regarding the inspection plan of reactor coolant sta1niess steel piping during the 1985 refueling cutage at Millstone Unit 1 plant. The licensee, NNECO, indicated that a total of 111 piping welds, including one unrepaired weld and seven overlay repaired welds in the recirculation system, core spray system, low pressure coolant injection system, shutdown cooling system, reactor water clean-up system, isolation condenser system, and jet pump instrumentation nozzle assemblies will be ultrasonically inspected. Those welds were selected to meet the guidelines in NUREG-1061 and to fulfill the licensee's other commitments. Based on our

- review, we conclude that the subject inspection plan proposed-by the licensee is satisfactory. Nevertheless, we provide the following comments, based on our judgement, considering the results of recent inspections conducted under Generje Letter 84-11.

(1) The recently reported ultrasonic inspection results by the utilities have shown that the performance by the qualified UT personnel lacks uniformity and consistency. To resolve this concern, the NRC has determined that all UT personnel performing detection and evaluation should be requalified at the EPRI NDE Center. EPRI is expeditiously setting up the testing facilities for the requalification at the NDE Center and expects the requalification to begin no later than September 15, 1985. We suggest that the licensee contact the EPRI NDE Center to arrange for a requalification of the UT personnel to be used in the 1985 outage at the earliest possible date.

(2) The UT personnel performing the inspection of the overlay repaired welds should be trained and qualified at the NDE Center, using the demonstrated procedures and techniques.

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l Mr. John F. Opeka August 14, 1985  ;

(3) The prepared inspection plan, although stated to be based on the recort:endations in NUREG-1061, Vol.1, may not provide the degree of assurance intended for some categories of welds, considering results of recent plant inspections. This may mean that future inspections will need to be somewhat more extensive after firm guidelines have been developed.

(4) The allowable flaw sizes in Code IWB-3640 are currently revised to take account of the low toughness associated with the flux welds.

The revised Code IWR-3640 is expected to be published soon. Prior to the publication of the revised IWB-3640, the staff has developed interim guidelines in the use of IWB-3640 to derive the allowable flaw sizes for the flux welds. The key points of the staff interim guidelines are summarized below:

(1) The secondary stresses (cainly thermal stresses) should be included in the calculation of the stress ratio.

(ii) The flaw size linits for the flux welds are 2/3 of the Code IWB-3640 allowables at a stress ratio as modified by (i).

Therefore, some unrepaired welds previously justified for continued service now require overlay repair.

I trust the above information will be factored into your efforts as appropriate.

If you have any questions, please contact Jim Shea, your NRC project manager.

Sincerely, MW stened byg John A. Zwolinski, Chief Operating Reactors Branch #5 Division of Licensing cc: See next page DISTRIBUTION Docket BGrimes NRC PDR JPartlow Local PDR JShea ORB #5 Rdg CJamerson HThompson JZwolinski OELD ACRS (10)

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Pr. Jchn F. Opeka Millstone Nuclear Power Station Northeast Nuclear Energy Company Unit No. 1

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CC:

Gerald Garfield, Esquire Kevin McCarthy, Director Day, Berry & Howard Radiation Control Unit .

Counselors at Law Pepartment of Environmental City Place Protection u=-+#ard Connecticut 06103-3499 State Office Building Hartford, Connecticut 06106 Edward J. Mroczka Vice President, Nuclear Operations Northeast Utilities Service Company Post Office Box 270 Hartford, Connecticut 06141-0270 State of Connecticut Office of Policy and Management

- ATTN: Under Secretary Energy Division 80 Washington Street Hartford, Connecticut 06106 Peoional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue vino of Prussia, Pennsylvania 19406 Northeast Nuclear Energy Company ATTN: Superintendent Millstone Nuclear Power Station P. O. Box 128 Waterford, Connecticut 06385 Resident Inspector c/o U.S. NRC Millstone Nuclear Power Station P. O. Box 811 Niantic, Connecticut 06357 First Selectman of the Town of Waterford Hall of Records 200 Boston Post Road Waterford, Connecticut 06385