ML20054M475

Independent Seismic Design Verification,Turbine Driven Section Emergency Feedwater Sys, Status Rept

ML20054M475
Person / Time
Site:	Summer
Issue date:	07/09/1982
From:	STONE & WEBSTER ENGINEERING CORP.
To:
Shared Package
ML20054M474	List: ML20054M473 ML20054M475
References
NUDOCS 8207130471
Download: ML20054M475 (10)

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? STONE & WEBSTER ENGINEERING CORPORATION I

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I INDEPENDENT SEISMIC DESIGN VERIFICATION TURBINE DRIVEN SECTION EMERGENCY FEEDWATER SYSTEM V.C. SUMMER NUCLEAR STATION STATUS REPORT: JULY 9, 1982 I

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1. INTRODUCTION:

1.1 GENERAL SCOPE Stone & Webster Engineering Corporation (SWEC) was engaged by I South Carolina Electric & Gas Company (SCE&G) to perform an independent review of the seismic design for the Turbine Driven portion of the Emergency Feedwater System at V.C. Summer Nuclear I Station, Unit No. 1. The review consisted of three major tasks, specifically; I 1) 2)

Field Walkdown: Verification of the as-built piping configuration Stress Analysis and Evaluation: reanalysis of the as-built piping system, review of stresses and support loads, and I 3) Design Control Audit: review of the design control pro-cedures and implementation thereof by Gilbert Associates Incorporated (GAI), the designer of V.C. Summer Nuclear Station, Unit 1.

1.2 STONE & WEBSTER QUALIFICATIONS AND INDEPENDENCE SWEC has extensive experience in the engineering, design, con-struction and startup operations for nuclear power plant projects as well as special expertise involving seismic design analysis, field verification efforts, and pipe stress and support reanalysis required by recent NRC I&E Bulletins. SWEC also has extensive experience in Quality Assurance aspects of the nuclear power in-dustry and in auditing of large highly technical and complex pro-jects. Stone & Webster is justifiably proud of its record and large staff of capable and experienced personnel.

SWEC, its parent company Stone & Webster, Inc., its affiliated companies and all personnel assigned to this evaluation are in-dependent of South Carolina Electric & Gas Co.

Work performed by Stone & Webster and its affiliated companies for SCE&G represents only a miniscule portion of Stone & Webster's business. All key technical personnel assigned to the project I signed disclosures (Attachment 1-1) . Table 1-1 lists personnel assigned to the various tasks. Dr. P. Dunlop, Project Manager, has overall responsibility for the project. Dr. K. Y. Chu is Project Engineer responsible for the technical evaluation (Tasks 1 and 2) and is independent of Mr. J. H. MacKinnon who is respon-sible for auditing the GAI design control program (Task 3).

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1.3 EVALUATION PROCESS All work was performed in accordance with project procedures I (Table 1-2) . Whenever a reviewer noticed anything outside the criteria, or had any question about the information or data, the reviewer highlighted this. Specific procedures for highlighting questions were different for each of the three major tasks and I are explained in the task specific project procedures (Table 1-2).

1.3.1 Field Walkdown (as-boilt verification)

All field measurements were recorded directly on piping isometrics.

Whenever the measured values differed from the isometric values by more than the criteria presented in VCS-1 Field Walkdown Procedure, the recorded values were circled on the isometrics and also recorded on Difference List (DL) Forms. Copies of the marked-up isometrics and DL forms were provided to SCE&G at the end of the Field Veri-fication Effort.

1.3.2 Stress Analysis and Evaluation All analyses are to be performed in conformance with VCS-3, Analysis and Evaluation Procedure and VCS-4, Analysis and Evaluation Criteria.

These provide the procedures and criteria for performing the piping I reanalysis. Procedures for highlighting differences are defined in Procedure VCS-3. Questions raised by the stress analysts are for-mally recorded and resolved. A two step procedure is used. An Open Item Report (OIR) is initiated for all items requiring clarification or confirmation. If a satisfactory resolution is received, the OIR is formally closed out. If a possible error or inconsistency is confirmed a Potential Discrepancy (PD) is written. These PD's will I be formally transmitted to SCE&G for their revier and evaluation.

1.3.3 Design Control Audit Of the three tasks the procedures and resolution of items for this task are more subjective. The personnel assigned to this effort were certified auditors and performed the audit in conformance with gen-I eral Stone & Webster standards for such audits.

2.O PROGRAM STATUS As of July 9, 1982, SWEC has completed Tasks 1 and 3. Task 2 is currently in progress. To date nothing has been found which would require the initiation of a 10CFR21 review. The detailed status of each task is given below.

Task 1: Field Walkdown - verification of the as-built piping geometry. This task has been completed and all Difference List (DL) items have been forwarded to SCE&G for their review and information.

The following is a brief description of the differences identified.

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(1) Gaps between piping and support steel larger than criteria -

two occurrences. The largest of these was 9/32 inch whereas the criteria allowed only 5/32 inch.

(2) Clearances between piping and structural components - three occurrences. Two instances of small clearance between pipe and structural component (0 and 7/64 inch) to be reviewed during stress analysis. A sleeve through a wall was also fo.und to be partially grouted. This was subsequently deter-mined to have been identified by SCE&G (ECN 2316) and the grout had been removed when SWEC field personnel again visited the site on June 7, 1982.

(3) Struts at angles other than identified on the isometrics -

three occurrences of struts more than 3 degrees from the values on the isometrics. The maximum difference was 11 degrees.

s (4) Dimensional data outside the criteria specified for SWEC's field walkdown effort - 15 occurrences. The maximum difference was 5.3 inches for a span of 11.6 feet. All dimensional differences were within SWEC's standard criteria.

(5) Drafting Errors - five occurrences. These were confirmed by reviewing the support or piping drawings.

All field measured dimensions will be input to the stress analysis in Task 2. Any impact of the above on the stress analysis will therefore be obtained.

Task 2: Stress Analysis and Evaluation - reanalysis of the piping system with as-built geometry, comparison of pipe stress with allow-ables and support loads. This task which consists of coding piping /

support geometry and design criteria into the NUPIPE program is currently in progress. No detailed results have yet been obtained to compare with the piping allowable stress or with the original design loads for supports. Three inconsistencies were identified during correspondence with GAI relative to design criteria. These are:

(1) During the field walkdown and subsequent data review it was found that several supports on subsystem EF-01 were in the Diesel Generator Building. This subsystem therefore should be analyzed considering seismic response spectra from the Diesel Generator Building. The piping isometric does not indicate this requirement.

(2) During reivew of data received an inconsistency in jet orientation and jet location was identified.

(3) In one instance the target area of a jet impingement in the design document (1902) appeared to be inappropriate.

Subsequent communication indicates that the jet need not be included in the' analysis because shield installation negates this break load.

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I It is not known what impact these inconsistencies might have on the detailed stresses and support loads in the piping reanalysis. This task is expected to be complete by July 27, 1982.

Task 3: Design Control Audit - This task consists of three parts.

These are:

(1) Review of the GAI design control program (2) Verification of program application (3) Confirmation that the structural dynamic analysis output was consistent with response spectra provided to Teledyne

' Engineering Service (TES) for analysis of the turbine driven portion of the Emergency Feedwater System.

The above three parts of this task have been completed. The following are SWEC's conclusions based on the design control audit.

Procedural Program An adequate Design Control Program, meeting the requirements of I 10CFR50 Appendix B, was in place for the transmittal and utili-zation of input data for pipe stress analyses of subsystems EF-01, 02, 03 and 22 of the Emergency Feedwater Piping System.

Only one instance was observed in the existing program where there was no formally approved procedure. Although formal procedures were available for indexing of design and procure-I ment specifications, the maintenance and distribution of a mechanical specification index was performed using an undated, uncontrolled instruction with no evidence that the instruction had been approved. Although unapproved, the procedure was adequate and was being implemented.

Program Implementation The procedures associated with the activities reviewed during the audit were adequately implemented except that the utilization I of inputs to pipe stress analysis in some cases was not con-sistent with program requirements. The instances are apparently documentation problems that would not affect the design.

I The pipe stress analysis package for subsystem EF-01 did not utilize Figure 64 response spectra as specified on the isometric. Although GAI had approved the deletion of Figure I 64 in a request for information (RFI) there was no evidence I 4 STONE & WEBSTER

that the isometric had been marked-up to indicate that Figure 64 should be deleted nor was there documentation in the pipe stress analysis package that justified the I deletion of Figure 64 (such approved RFI) .

as by reference to the GAI o There was no documentation in the pipe stress analysis package for EF-22 that the differences between the thermal movements utilized in the analysis and the movements on the isometric had been evaluated. A letter to GAI from TES I initiated as a result of this audit indicated that the {

differences had been evaluated when the analysis was per-formed and that reanalysis was not necessary.

o (The project scope was expanded to include SI-09 because of l the difference noted in EF-22 above). The pipe stress analysis package for subsystem SI-09 apparently utilized ancher movement information from aWestinghouse letter rather than the movements identified en the isometric. There was no evidence that GAI had approved or transmitted this information for use. In addi-I tion, the pipe stress analysis package did not identify that the movements utilized were different than the isometric and the reasons for the differences. A letter submitted by TES to GAI as a result of the audit indicated that the Westinghouse anchor movement information had been used in the analysis.

o The nozzle loadings in pipe stress analysis packages were noted lI i

as acceptable by " trade-off". There was no documentation in l l the pipe stress analysis packages that identified the method or l t

the acceptability of the method. There were approved RFI's l I in GAI files that addressed load trade-offs, but they were not referred to in the packages.

l Another area that was not clearly documented was the application of damping factors. Although the application of damping factors complied with the PSAR, this could not be discerned unless reference was made collectively to the PSAR, Specification 702, pipe stress analysis  !

packages, a GAI study, and minutes of a meeting. The underlying cause of this condition was apparently due to not updating Specification 702 to reflect the issuance of Amendment 26 to the FSAR.

Response Spectra Consistency The response spectra utilized in the pipe stress analysis was consistent with the dynamic (structural) analysis output. In some cases additional spectra were utilized when it did not appear necessary. Utilization of these additional spectra adds to the I conservatism of the design.

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4 l' ATTACHMENT l-1 I, ,/

J.O. 14236 i ,.

. INDEPENENTSEISMICDESIGNVERIFICATION V.C. SUMMER NUCLEAR STATION, UNIT N0. 1 I ' SOUTH CAROLINA ELECTRIC & CAS CO.

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, Statement Regarding Potential or Apparent

, ,, Conflicts of Intercot l,

ia , Te,: Stone'& Webster Engineering Corporation 1 .i

<W reas, the undersigaed employee ("E=ployee") understands that he or she

'is assigned as a partic3 pant to provide services to Sot.th Carolina Electric. f. Cas Company Nith , respect to the Design Verification Program for the'V . St,z:mer huclear Station; and Whereas E=gloyee onderstands that it is necessary that the participan.ts be screened for eny potential or apparent conflicts of interest with respect ':o this ansignment;

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Thereforji f o r th< abov,e stated purposes Employee makes the following representations tc. Stone & Webster Engineering Corporation:

1. h.mployeehasnotyn[agedinanyworkorbusinetsinvolvedwith or related to the engineer,ing or design of the V.C. Su==er Nuclear Station yrher than.this Deqign Verification Program;

2. Neither Employee, nor any members of his or her i= mediate family, own any beneficial interest in the_ South Carolina Electric &

Gas Company, including but not limited to common or preferred stock, bonds or other securities issued on behalf of the South Carolina Electric & Cas' Company; and

3. None' of ths rembers of Employee's immediate family are employed I by South Carolina Electric & Gas Company.

This statement is based upon the Employee's best information and belief and any exceptions to the representatioas contained herein have been described on the reverse side of this document.

, j Dated

. Signature _ g ,

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TABLE l-1 PROJECT PERSONNEL Project Manacer: Peter Duninp

. Proiect Encineer: K. Y. Chu . Desien Control Audit Manacer:

. Assistant Proiect Encineer: J. F. Pa:n J. H. MacKinnon TASK 1 FIELD WALKDOWN TASK 3 DESIGN CONTROL AUDIT N. Roth D. Malone I K.

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D.

Anderson Y. Chen Loffa R. Twigg A. Moss j L. Peterson l V. Saleta TASK 2 STRESS ANALYSIS AND EVALUATION T. Wei D. Loffa J. Y. Chen J. Chiang Y. Chin J. Chu I

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TABLE l-2 PROJECT PROCEDURES (A) TASK SPECIFIC PROCEDURES FIELD WALKDOWN EFFORT VCS-1 Field Walkdown Procedure STRESS ANALYSIS AND EVALUATION VCS-3 Analysis and Evaluation Procedure VCS-4 Analysis and Evaluation Criteria l

DESIGN CONTROL AUDIT Design Control Verification Plan (B) PROJECT CENERIC PLANS / PROCEDURES Quality Assurance Plan Document Control Procedure - VCS-2 Quality Assurance Records Procedure - VCS-5 Engineering Assurance Audit Program I

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