ML20212N020

Safety Evaluation Denying Util 860325 Request for Relief from Inservice Insp Requirements of ASME Code Section XI, Table IWC-2500-1 for Volumetric Exam of HPCI Pump Studs

ML20212N020
Person / Time
Site:	Brunswick
Issue date:	08/22/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20212M855	List: ML20212M852 ML20212N020
References
NUDOCS 8608280045
Download: ML20212N020 (3)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

_ RELATING TO REQUESTS FOR RELIEF FROM INSERVICE INSPECTION REQUIREMENTS CAROLINA POWER AND LIGHT COMPANY BRUNSWICK STEAM ELECTRIC PLANT UNIT 2 DOCKET NO.:50-324 BACKGROUND Technical Specifications 4.0.5 for the Brunswick Steam Electric Plant Unit 2, states that inservice examination of ASME Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and Applicable Addenda as required by 10CFR50.55a(g) except where written relief was granted by the Commission. Certain requirements of latrr Editions and Addenda of Section XI may be impractical to perform at older plants because of plant design, component geometry, and materials of construction. Paragraph 10CFR 50.55a(g)(6)(i) authorizrs e the Commission to evaluate the determination made by the licensee and grant relief from impractical ASME Code requirement and impose alternative requirements when the Commission deems added assurance of component reliability is necessary.

Carolina Power and light Company (CP&L) submitted the inservice inspection (ISI) program and information related to the determination that certain ASME Code requirements were impractical to perform at Brunswick Units 1 and 2 in letters dated June 30, 1978, January 30, 1980, March 2, 1981, May 20, 1981, and June 18, 1982. The program for the current inspection interval is based ,

on the 1977 Edition, Summer 1978 Addenda of Section XI of the ASME Code. The termination dates for the current inspection interval are March 17, 1987, and November 2, 1985, respectively, for Units 1 and 2. The Commission approved a common starting date of July 10, 1986, for the second inspection interval for both units.

t RELIEF REQUEST By letter to the Commission dated March 25, 1986, the licensee requested relief from the ISI requirement for the full-volumetric examination of tha high pressure coolant injection (HPCI) pump studs. The licensee stated tier.

the examination was impractical to perform and presented information to conf,irm their determination.

8608280045 860822 4 PDR ADOCK 0500 G

CODE REQUIREMENT Examination category C-D, pressure retaining bolting greater.than 2 in. in l diameter, Table IWC-2500-1, Item C 4.30, pumps, require 100% volumetric  ;

examination of bolts and studs at each bolted connection during each inspection interval.

BASIS FOR REQUESTING RELIEF There are seventeen pumps studs involved in this request. The studs connect the upper and lower HPCI pump casing. The licensee stated that the examination requirement was impractical to perform because cap nuts, tensioned to 8000 foot pounds, cover the studs and prevent examination from the top surface. In place examination was conducted from the bottom surface on nine of the studs, but physical constraint prevented examination of the remaining eight studs. Specialized equipment, currently not located at the site, is required to remove the cap nuts. It was estimated that the current outage would be extended a minimum of four weeks to obtain the specialized equipment and conduct the ASME Code examination, resulting in an equivalent loss of reactor operation time. Radiation exposure to personnel was estimated to be 9.6 man-rem. In addition, there is a probability of pump damage, which, if occurred, would extend the outage an undetermined length of time beyond the four week period.

ALTERNATE EXAMINATION The licensee proposed an alternate examination program in lieu of the ASME Code requirement of 100 percent volumetric examination of the HPCI pump studs. The alternate program consisted of the in place volumetric examination of nine studs, equivalent to approximately 80 percent of total length, supplemented by visual examination (VT-2) at least once every ninety-two days of reactor operation to assure HPCI pump integrity. The ASME Code required examination would be delayed and scheduled for completion' during the next plant refueling outage in January,1988.

STAFF EVALUATION The staff has evaluated the determination and disagrees with the licensee that conformance to this ASME Code requirement for Brunswick Unit 2 is impractical. We concluded that relief should not be granted for the requirement of full-examination of HPCI pump studs since the licensee was aware that stuo' nut cap removal was necessary to perform the examination, during the past refueling outage.

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L Paragraph IVA-2400 (c) permits extension of an inspection interval by as much as one year (but net cumulatively). Further, the paragraph permits extension of the interv'al for an additional period of time equal to the duration of an outage if tne outage were longer than six months. Brunswick Unit 2 was out cf service for a period of eight months for various maintenance and system modifi-cation activities. Therefore, this one remaining examination should be

, completed by July 2, 1987, to satisfy the requirements of the ASME BP&V Code, Se,ction XI in terms of the expiration of the first inspection interval.

Principal Contributor: F. Litton Dated:

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