ML20207B320

Responds to Generic Ltr 88-01 Re NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping.Util Intention Is to Continue W/Implementation of IGSCC Insp Program as Previously Submitted.No IGSCC Detected

ML20207B320
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	07/25/1988
From:	Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
RTR-NUREG-0828, RTR-NUREG-828 GL-84-11, GL-88-01, GL-88-1, IEB-83-02, IEB-83-2, NUDOCS 8808020299
Download: ML20207B320 (4)

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] Nuclear Regulatory Commission Document Control Desk j Washington, DC 20555 i .

I DOCKET $0-155 - LICENSE DPR BIG ROCK POINT PLANT - RESPONSE TO GENERIC j LETTER 88-01, NRC POSITION ON IGSCC IN BWR AUSTENITIC STAINLESS STEEL PIPING f

I Ceneric Letter 88-01, NRC position on ICSCC in BWR austenitic stainless steel pipieg, dated January 25, 1988 requested Consumers Power Company to furnish under oath or affirmation our current plans relating to piping replacement, inspection, repair and leskage detection relative to Intergranular Stress Corrosion Cracking (ICSCC) in BWR piping systeas. Our response to the generic letter is provided herein.

To dste, after nearly 26 years of operation Big Rock Point has not detected l

3 any IGSCC, Even though none has been found, we continue to research our lack i of ICSCC and/or the extremely slow grewth rate of this corrosion phenomena at l 4

Big Rock Point. Consumers Power Company letter deced November 13, 1987 in i a response to Generic Letter 84-11 provided the NRC our ICSCC detailed inspection  !

j program and plans. During the recently completed 1988 refueling outage, we l j completed the first item of this program, which included inspections for ICSCC

of 16 velds which had previously not been examined. None of the velds had any  ;

! indications of ICSCC. During the next refueling outage another 15 velds not I previously inspected will be examined and all accessible ICSCC susceptible l l velds vill have been examined at least once. Our intention is to continus

with the implementation of our ICSCC Inspection Program as previously submitted. (

The specific items identified in the generic letter are addressed below. l Item 1 - Plans Regarding Pipe Renlacement ,

Piping replacement and other measures to mitigate ICSCC (Solution Heat Treatment, Heat Sink Veldings or Stress Improvement) are not presently warranted at Big Rock Point. These measures, including pipe replacement, are logical and  ;

3 prudent acts to assuro safety and reliability when ICSCC is found within a ,

i system. However, since Big Rock Point has not detected IGSCC, introduction at I l this time of some or most of these eessures would incur significant personnel j exposures that contradict ALARA principles.  :

OC0788-0078-Nt02

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Nuclear Regulatory Commission 2 Big Rock Point Plant '

Response to Generic Ltr 88-01 4 July 25, 1988 Item 2 - ICSCC Inspection Program Per the generic letter, category "D" welds are defined as those which are I

susceptible and have been previously inspected and category "G" welds are those which are susceptible and have not been previously inspected. ,

The susceptible welds at Big Rock Point have been categorized as "D" or "G".

l Some of the category "G" welds are not accessible for inspection for manual or remote examination. The remaining category "G" welds (15) which are accessible will be examined during the 1989 refueling outage. When these 15 examinations are completed, all susceptible velds that are accessible will have been examined at Icast once using procedures and personnel that are qualified for  ;

, detection per the requirements of NRC Bu111etin 83-02 and Ger.eric Letter, 84-11 and 88-01. Some of the category "G" welds that are normally inaccessible l will be examined at the end of the 10 year ISI interval because they can be j accessed only from the reactor vessel interior. With respect to the remaining t inaccessible Category "G" welds, they are routinely leak checked approximately annually in conjunction with the required plant leak test conducted on all startups from refueling outages in accordance with relief granted by NRC letter dated November 1, 1985 for our normal ISI program.

Item 3 - Technical Specification Revisions Welds susceptible to ICSCC have been identified in the Big Rock Point ISI Master Plan, Rev 6, part VII Examination Scheduling Tables. Por our IGSCC l Inspection Program, the schedule for examination of accessible susceptible welds will be reassessed after the 1989 refueling outage. Therefore, entry of schedule of IGSCC examinations into Technical Specifications will not be done at this time. Hethods, personnel and sample expansion criteria are as stated ,

in our November 13, 1987 IGSCC Inspection Program.  ;

Item 4 - Leakas e Detection Per the NRC staff position stated in Generic Letter 88-01, leakage detection  ;

systems previously approved by the NRC need no further modification. i NUREC-0828 "Integrated Plant Safety Assessment" Section 4.16. Topic V-5, dated May, 1984 states Big R uk Point satisfies the requirements of Regulatory Guide ]

1.45 for leakage detection based upon commitment for , recedure revision to j accomodate seismic concerns which have been implemented. Since this evaluation constitutes previous approval of leak detection system (s) per Regulatory Guide 1.4!, no modifications to this system are required.

Item 5 - NRC Notification Flaws found in the ISI program are assigned deviation reports for disposition.

Inspection results are tabu?rced in the final ISI report which is provided in OC07SS-0078-NLO2

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. i Nuclear Rsgulatory Commission 3 Big Rock Point Plant Response to Generic Ltr 88-01 July 25. 1988 1 writing to the NRC after each outage. Evaluation, analysis and repair of flaws is addressed in our referenced IGSCC Inspection Program. Sample expansion, analysis and evaluation is per ASME Section XI requirements. Flaws found by ICSCC examinations vill be reported to the NRC for approval of corrective action methods.

$ .J Kenneth W Berry Director. Nuclear Licensing CC Administrator Region III. NRC NRC Resident Inspector - Big Rock Point i

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OC0788-0078-NLO2

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CONSLHERS P0k'ER COMPANY Big Rock Point Plant Docket 50-155 License DPR-6 Response to Generic Letter No 88-01 dated January 25. 1988 At the request of the Commission and pursuant to the Atomic Energy Act of 1954 and the Energy Reorganization Act of 1974. as amended, and the Cormission's Rules and Regulations thereunder. Consumers Tower Cenpany submits our response to NRC letter dated January 25. 1988 entitled "dRC Position on ICSCC in Bk'R Austenitic Stainless Steel Piping." Consumers Power Company's response is dated July 25. 1988. .

CONSLHERS P0k'ER COMPANY By \ [b DavidPHoffmanJ{ijePresident Nuclear Operations Sworn and subscribed to before me this 25th day of July, 1988. r

,o , o 1 b <tl A Elaine E buehrer. Notary Public Jackson County, Michigan My commission expires October 31, 1989 I

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OC0788-0076-NLO2

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