ML20245D832

Submits Clarification on Two Items Discussed During 880721 Meeting on Design Baseline & Verification Program

ML20245D832
Person / Time
Site:	Sequoyah
Issue date:	09/30/1988
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8810070211
Download: ML20245D832 (5)

Text

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7 TENNECSEE VALLEY AUTHORITY I ' CHATTANOOGA TENNESSEE 37401 SN 1578 Lookout Place SEP 301988 U.S. Nuclear Regulatory Commission ATTN: Doctnent Control Desk Hashington, D.C. 20555 Gentlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - CLARIFICATION OF THE JULY 21, 1988 TVA/NRC MEETING ON PHASE II 0F THE DESIGN BASELINE AND VERIFICATION PROGRAM (DBVP)

Reference:

NRC letter dated August 4, 1988, " Minutes of the July 21, 1988 Meeting with the Tennessee Valley Authority on Phase II of the Design Baseline and Verification Program for Sequoyah" As discussed with the Office of Special Projects (OSP) by telephone, TVA has reviewed the referenced letter and identified two items that require clarification. The first item involves the two unit 1 phase I DBVP items that TVA stated were inadvertently omitted from the Sequoyah Nuclear Performance Plan (SNPP), revision 3. The second item involves the change document categorization and evaluation processes. The clarifications for both items are provided below. This information will supplement that provided during the July 21, 1988 meeting.

UNIT 1 DBVP OMISSIONS The first unit 1 phase I DBVP omission involves the review of unit 2 DBVP evaluations by the Division of Nuclear Engineering Review Board, composed of TVA and contract personnel, established for this purpose. Because of a misunderstanding on TVA's part, NRC was unfortunately left with the mistaken impression that the review board was used in the unit 1 DBVP.

This is not the case; however, the benefits of the review board process were passed on to the unit 1 DBVP in several ways.

The primary technical comment made by the review board addressed the unit 2 system evaluation reports (SYSTERs) and concerned the lack of sufficient rationale for a given judgement or conclusion. This concern was addressed in the unit 1 procedures at the request of the members of the review board, who actually served on the initial unit 1 DBVP procedure team.

Consequently, the unit 1 procedures require that, whenever a judgement or conclusion is called for, the rationale for that judgement or conclusion has to be stated. This rationale received independent peer review, system engineer review, interdisciplinary review, and several levels of management review before being issued as a final product.

In addition, the unit 2 SYSTERs, which were reviewed by the review board, were extensively used in the unit 1 DBVP. For 1.aplemented engineering change notices (ECNs), the majority affected both units; and the unit 2 review (as stated in the SYSTERs) was used "as is" for unit 1.

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4 SEP 301988 U.S. Nuclear Regulatory Commission for unimplemented and partially implemented ECNs affecting both units, a decision was made on whether further review for unit I was necessary, based on the evaluation of that ECN in the unit 2 SYSTERs.

For the remainder of the unit 1 DBVP, the benefits of the review board were incorporated by the experience gained by DBVP management and staff, which remained substantially intact for unit 1. Additional procedure enhancements were made based on this experience. SQN engineering procedures (SQEPs) 46, 48, 55, and 70 for unit 1 DBVP were developed as a result of lessons learned from the unit 2 DBVP effort.

TVA believes that the experience of the review board process was adequately incorporated into the unit 1 review process and that having a review board for unit I would have been a duplication of effort and would not have substantially improved the unit 1 final product. This change was approved by the DBVP program manager and reviewed by the engineering assurance oversight team and was found to satisfy the intent of the review board.

The second omission involves corrective action reviews for potential impact on equipment qualification (EQ) program requirements. The EQ program requirement review was performed as part of the plant design control process independently of DBVP.

Change Document Categorization for unit 1, SQEP-46 established a multidiscipline baseline categorization team (BCT) to review the changes, determine the involved systems and disciplines, and identify the lead discipline for evaluating the change. The BCT consulted the unit 2 SYSTERs, punch list items, etc., in order to determine if additional review was required for unit 1.

The counterpart procedure for unit 2 was SQEP-11. This procedure required a senior discipline engineer (SDE) to make an initial determination of system involvement. The system engineer (SE) then assessed the SDE conclusion for the particular system. Based on this SE concurrence, a change document was considered in-bounds or out-of-bounds for a particular system.

Change Document Evaluation For unit 1, SQEP-48 defined a task engineer (TE) who was assigned by the discipline evaluation supervisor (DES) of the lead discipline. The TE combined reviews performed by the involved disciplines for a given change document. These evaluations consisted of technical narratives supporting / justifying the adequacy of the change based on the requirements of the restart design basis document (RDBD). The responsible SEs then reviewed and concurred with those evaluations.

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> SEP 301988 i

U.S. Nuclear Regulatory Commission For unit 2, SQEP-12 required an SE review of all changes affecting a system.

The SE evaluation ensured that the change was technically adequate, in l

compliance with procedures, and consistent with design requirements (i.e.,

RDBD). A design review checklist was completed by the SE from individual discipline-specific checklists for each change document affecting that system. These checklists were used as the basis for technical narratives, which were included in the SYSTERs to justify the adequacy of the change.

Both processes for units 1 and 2 meet the objectives of the DBVP. Change documents were categorized and evaluated for technical adequacy. The basis / rationale for these categorization and adequacy determinations were documented and reviewed by SEs and DBVP management. DBVP management considers these two processes to be equivalent.

TVA regrets that, because of an oversight, these differences were not made clear to NRC earlier.

Summary statements of commitments contained in this submittal are provided in the enclosure. Please direct questions concerning this issue to M. J. Ray at (615) 870-6422.

Very truly yours, TENNESSEE VALLEY AUTHORITY YRD4J//

R. Gridley, Manager Nuclear Licensing and Regulatory Affairs Enclosure cc: See page 4

SEP 301988, U.S. Nuclear Regulatory Commission.

cc (Enclosure): .

Ms. S. C. Black, Assistant Direct'or for Projects-1 TVA Projects Division l U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. F. R. McCoy, Assistant Director for Inspection Programs TVAProjectsDivision U.S. Nuclear Regulatory Commission Region II 101 Marietta Street,' NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379

~.,,

. ENCLOSURE 1VA will revise the SNPP to clarify unit 1 phase I DBVP items.

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