ML20126B108
| ML20126B108 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/17/1992 |
| From: | Zeringue O TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M83827, NUDOCS 9212210382 | |
| Download: ML20126B108 (5) | |
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,-~non w. --.v in, ~. m O J W 7enogue um bewmt bvwns fer y tesaar Kru DEC 171992 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
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Docket Nos. 50-259 Tennessee Valley Authority
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50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING BFN UNITS 1 and 3 COMPONENT AND PIECE PARTS QUALIFICATION t
PLAN (TAC HOS.'M83827 AND M83828) i
References:
1.
TVA letter from R. R. Baron dated June 12, 1992, to NRC - Request For Revision to Safety Evaluation Issued by--NRC on January 10, 1990, Related to Component and Piece Part Qualification Plan.
L 2.
NRC letter from Frederick J. Hebdon dated October 29, 1992, to Dr. Mark _0.
Medford - RAI'on BFN Units 1 and 3 Components and-Piece Parts Qualification Program, l
l This letter revises the' Components Piece Parts Qualification Plan for BFN l
Units 1 and 3 that was submitted by Reference 1 and responds to NRC questions contained in-Reference 2.
These questions were a result of the meeting held on September 15, 1992, between the NRC Staff and TVA L
representatives in Rockville, Maryland, to discuss TVA's revised plan.
l L
TVA considers that the information requested by NRC has'been provided by-the Enclosure and requests the issuance of a revised Safety Evaluation Report.
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U.S, Nuclear Regulatory Commission gEC 171992 There are no commitments contained in this letter.
If you have any questions, telephone Greg Pierce, Interim Manager of Site Licensing, at (205) 729-7566.
Sincerely,
~0. J. Zerin Enclosure cc (Enclosure):
NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35611 Mr., Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North
'11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 l
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ENCLOSURE BROWNS PERRY NUCLEAR PLAN (BFN)
UNITS 1 and 3 COMPONENT AND PIECE PARTS QUALIFICATION PROGRAM 1.
NRC Question Clarify the distinction between the Component and Piece Parts Qualification Program described in TVA's June 12, 1992 letter and the Environmental Qualification Program required by 10 CFR 50.49.
TVA Response Under TVA's program for Environmental Qualification (EQ) the 10 CFR 50.49 equipment is evaluated for compliance with 10 CFR 50.49 and that evaluation is documented in an Environmental Qualification Data Package (EQDP). The EQDP is a design output document that provides an auditable record for demonstrating -
compliance with 10 CFR 50.49 environment.
The Component and Piece Part Qualificc-tion Program was establidied to evaluate, the inventoried and installed piece parts of a component. This program was not designed to provide 10 CFR 50.49 qualification of. equipment. The Component and Piece Part Qualification Program provides an additional review to ensure that a previously qualified EQ component was not degraded due to the introduction of unqualified piece parts.
2.
NRC Question Discuss the statistical basis for the sample size selected, including justification that the sampled population is homogeneous for this purpose.
TVA Response Upon further revies, TVA has concluded that the 9;/95 sample plan originally proposed, with a sample size of 59' items, was inappropriate since it was-developed for an infinite-population of 500 or more items. TVA has elected to use the sample plan from EPRI NP-7218. The basis for using the'EPRI plan is that the estimated population of 500 components consist of approximately 30 different types of components and the population size of each type varies.
Grouping the components by functioaal or component type vill ensure-homogeneity of the components and results in lots of considerably smaller size. Accordingly, the sample methodology contained in EPRI NP-7218 is more suitable for the smaller lots.
This EPRI sample plan methodology will group the components within the scope of the Unit 3 and 1 effort into_like commodities to establish homogeneous sample lots. TVA will then apply the Reduced Sample Plan from Table 2-1 EPRI NP-7218, Guideline for the Utilization of Sampling Plans for Commerical-Grade Item Acceptance (NCIG-19), to develop the. sample size for.each of the j
respective lots.
The following defines the homogeneity of each sample population:
- The components within each lot are within TVA's 10 CFR 50.49 EQ Program for Units 1 and 3.
- The components within each lot will be of the same functional or component type (e.q, transmitters, level switches, motor operators, temperature elements, and flow switches).
- The components within each lot will be evaluated using the same failure criteria.
The following provides the bases for using the Reduced Sampling Method
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contained in Table 2-1 of EPRI NP-7218:
- A 100 percent review was performed for Unit 2 and only 16 nonconforming items were identified. This represented less than one percent of the population.
- Components installed in Units 1 and 3 are similar to those components installed and evaluated in Unit 2.
- The Unit 2 effort revealed that the majority of the piece parts were purchased from reputable vendors. The vendors were on TVA's Approved Suppliers List and had a quality program, which was approved and accepted by TVA.
The Units 1 and 3 piece parts were purchased in the same manner.
Specifically, Units 1 and 3 piece parts were often procured on the same purchase orders and/or with the same vendors as the Unit 2 piece parts.
3.
NRC Ouestion Discuss what conditions constitute a discrepancy, and what actions TVA will take if discrepancies are identified.
TVA Response A discrepancy, as it pertains to the Component Piece Part Qualification Plan, is defined as:
"Any piece part lacking sufficient documentation to support the part's ability to perform its function in the installed environment." The following provides examples of the types of deficiencies that may be identified:
- No traceability to a manufacturer's test report.
- No traceability to a TVA test report or test report from an independent facility.
- No documentation to support the part's similarity to a qualified piece part.
TVA plans to take the following actions if a discrepancy is identified. For a lot size of less than 100 components, if one defect is found, then the entire 3
lot will be evaluated. For a lot size greater than 100 components, if one defect is found, then the original sample vill be disqualified. The number originally sampled vill be subtracted from the original lot size. The remaining lot vill then be sampled using the Tightened Sample Plan from Table 2-1 of EPRI NP-7218.
Discrepancies identified during the Unit 3 effort will be dispositioned in accordance with TVA Administrative Control Programs.
Examples of such dispositions would be to replace the unqualified piece part, remove the items from inventory, or restrict the issue of an item to nonsafety related applicatlons.
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