ML20215G519

Responds to Unresolved Concerns in NRC 860204 Evaluation of Util Response to Generic Ltr 84-11, Insps of BWR Stainless Steel Piping. Compliance W/Reg Guide 1.45 Demonstrated.No Changes to Tech Specs Re Leakage Detection Sys Needed

ML20215G519
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	10/13/1986
From:	Frisch R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Office of Nuclear Reactor Regulation
References
RTR-REGGD-01.045, RTR-REGGD-1.045 GL-84-11, IEB-80-32, NUDOCS 8610200411
Download: ML20215G519 (5)

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CORSumBIS Power powmanus AIEMEAM5 PNSERE55 oeneral offices: 1945 West Parnell Road, Jackson, MI 49201 * (517)'788-0550 October 13, 1986 Director, Nuclear Reactor Regulation-US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BlG ROCK POINT PLANT -

-ADDITIONAL IGSCC INSPECTIONS FOR GENERIC LETTER 84-11 Nuclear Regulatory Commission letter dated February 4, 1986 provided Consumers Power Company the NRC's evaluation of our response to Generic Letter 84-11, Inspection of BWR Stainless Steel Piping. This evaluation concluded that Big Rock Point's inspection sample size and technical specification leakage detection surveillance requirements do not meet the guidelines of Generic Letter 84-11. This submittal provides Consumers Power Company's response to the unresolved NRC concerns.

Inspection Sample Size Big Rock Point will examine 31 IGSCC susceptible welds as indicated in the attached Table 1 during the 1987 refueling outage. This number of examina-

tions is compatible with the Generic Letter 84-11 guidelines and the number i calculated by the NRC staff. Weld-examiners will be qualified to the require-ments of IE Bulletin 83-02 as specified by Generic Letter 84-11.

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Leakage Detection Surveillance Requirements The first of three NRC leakage detection concerns is related to visual inspec-

~ tion of piping leakage during each plant outage. Big Rock Point performs visual inspections of piping for leakage prior to startup from every refueling outage in the form of a full primary coolant system hydrostatic test. This test is required by our. NRC approved Inservice Inspection Program and imple-mented by plant procedure TV-10. It requires a minimum test pressure of 1,450 psig. Big Rock Point typical operating cycles average 11 to 13 months, and therefore, this test is performed approximately annually.

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. Big Rock Point Plant Additional IGSCC Inspections for GL 84-11 October 13, 1986 As specified in Part E of Attachment 1 to Generic Letter 84-11, ASME Code Section XI (1980 Edition) is used for the visual detection of leakage.

Section IWB 5000 of the same code. requires a system leakage test at every refueling while a hydrostatic test is only required once per ISI interval.

Since the Big Rock Foint hydrostatic test pressure is about 81% higher than-that cf a system leakage test, the hydrostatic test is more probable to detect a leak. This is. reinforced by the required four-hour hold time for the hydrostatic test. No hold times are required for system leakage tests. Big Rock Point maintains that the higher test pressure with a four-hour hold time done on an approximately annual basis is more effective in leakage detection than a system leakage test with no hold time and a lesser pressure.

The second NRC leakage detection concern is related to the frequency of leakage monitoring as specified in our technical specifications. This concern has been previously evaluated by the NRC on a plant specific basis as being acceptable for Big Rock Point. The February 4, 1986 NRC evaluation references draft NUREG-0313, revision 2 as endorsing a four-hour leakage monitoring frequency. Section 6.0 of this draft further states that acceptable leakage detection and monitoring are described in Position C of Regulatory Guide 1.45, Reactor Coolant Priessure Boundary Leakage Detection Systems. Also, this document states that other equivalent leakage detection systems will be reviewed on a ceae by case basis. Consumers Power Company submittals dated May 25, 1983 end June 6, 1983 provided information on Big Rock Point leakage detection systems. The NRC's evaluation of these submittals is dated June 13, 1983. This NRC evaluation concluded that Big Rock Point leakage detection systems meet or are equivalent to all of the recommendations in Regulatory Guide 1.45 with the exception to seismic qualification. To resolve this exception, Big Rock Point committed to revise emergency operating procedures-to require a leak test in the event of a confirmed seismic event. This requirement is implemented in emergency procedure EMP 3.7 subsequent actions.

The third NRC leakage detection concern is related to the inoperability period of the monitoring system. ' Equipment inoperability was also addressed in the June 13, 1983 evaluation. Determination (2) of this evaluation indicated that Big Rock Point ~ technical specifications contain adequate leakage detection system operability requirements as recommended by Regulatory Guide 1.45.

Summary Based on the above information, Big Rock Point has demonstrated compliance with Regulatory Guide 1.45 through a plant specific evaluation. In light of this compliance, technical specification changes are not warranted at this time. Big Rock Point will conduct 31 IGSCC weld examinations of susceptible piping welds during the 1987 refueling outage. Further, Big Rock Point is in OC1086-0167-NLO2

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, Director, Nuclear Reactor Regulation 3 Big Rock Point Plant Additional ICSCC Inspections for GL 84-11 October 13, 1986 progress of conducting a study to determine the basis-for the apparent lack of IGSCC at Big Rock Point over the 20-plus years of plant operation. This study will not impact the scheduled weld examinations in the upcoming outage.

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p Ral R risch.

Senior Licensing Analyst CC Administrator, Region III, USNRC NRC Resident Inspector - Big Rock Point Plant Attachment 1

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t *s TABLE 1 IGSCC WELD SELECTION DATA TABLE Pipe Size Total Susceptible Number of Welds Number of' Welds Number of Welds (in.) Welds Previously Exam. Not Exam. Selected for 1987 Outage 24 2 2 0 2-Minimum of those already examined 20 4 0 4 0-Severely Restricted accessibility 17 14 4 10 2-Minimum of those already examined 4-Minimum of those never examined 14 30 6 24 2-Minimum of those already examined 5-20% of those never examined 6 13 3 '10 2-Minimum of those alrdady examined 2-Only 5 welds accessible (total) 5 19 3 16 2-Minimum of those already examined 4-20% of those never examined 4 16 3 13 2-Minimum of those already examined 4-Minimum of those never examined IC0986-1042A-BTO1

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ATTACHMENT Consumers Power Company Big Rock Point Plant '

Docket 50-155 ICSCC WELD SELECTION DATA TABLE October 13, 1986 1 Page IC1086-0167-NLO2