ML20199E256
| ML20199E256 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 01/28/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20199E204 | List: |
| References | |
| REF-QA-99900404 NUDOCS 9802020116 | |
| Download: ML20199E256 (4) | |
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NOTICE OF NONCONFORMANCE Westinghouse Electric Corporation Docket Nos.: 52-003 Pittsburgh, Pennsylvania and 99900404 Based on the recults of a Nuclear Regulatory Commission (NRC) inspection conducted during the week of November 17 21,1997, of activities supporting Westinghouse Electric Corporation's AP600 design certification, it appears that certain activities were not conducted in accordance with NRC requirements.
A. Criterion lil, " Design Control," of Appendix B to 10 CFR Part 50, states, in part, "The design control measures shall provide for verifying or checking the adequacy of the design, such as by the performance of design reviews. by the use of altemate or simplified cal ulational methods, or by the performance of a suitable testing program."
ANSI /ASME NOA 1-1989 " Quality Assurance Program Requirements for Nuclear Facilities,"
Supplement 3S 1,"SJpplementary Requirements for Design Control," Section 4.2.1,
" Design Reviews," states that design reviews "are critical reviews to provide assurance that the final design is correct and satisfactory. Section,4.2.1, also states, in part, that where applicable, the following shall be addressed during such reviews:
. Were the design inputs correctly selected?
. Are assumptions necessary to perform the design activity adeouately described and reasonable? Where necessary, are the rssumptions identified for subsequent reverifications when the detailed design activities are completed?
- Were the design inputs correctly incorporated into the design?
- Is the design output reasonable compared to design inputs?
ANSI /ASME FlQA 1-1989, Supplement 3S-1, Section 3.1, " Design Analyses," states, in part, that design analyses documents "shall be suff;ciently detailed as to purpose, method, assumpticas, design input, references, and units such that a person technically qualified in the subject can review and understand the analyses an; verify the adequacy of the results without recourse to the originator,"
WCAP 8370, Westinghouse Electric Corporadon - Energy Systems Business Unit / Power Generation Business Unit - Quality Assurance Plan," Revision 2 (April 1992), Section 4.4.1,
" Design Reviews," states, in part, that independent reviews address the following, as applicable, " design input selection, described and reasonable design output compared to design input, design input and verification requirements from interfacing organizations, appropriate design method used, design inputs correctly incorporated into the design, and adequately described, reasonable, and identified assumptions."
Westinghouse Electric Corporation - Energy Systems Business Unit Policy / Procedure WP 4.17," Design Verification by Independent Review or Alternate Calculations," Revision 0 (8/31/96), states, in Section 8.3, that the assigned verifier" Verifies the adequacy of the design [ emphasis added] or changes thereto by independent review or attemate calculations."
9802020116 900129 PDR GA999 ENVWEST 99900404 PDR
The following examples demonstrate failure to comply with the above requirements and constitute Nonconformance 99900404/97 02-01.
Contrary to the above, the inspection team found that for the following AP600 calculations Westinghouse failed to perform an adequate design review to establish the acceptability of the corresponding AP600 design bases analyses:
- 1. SSAR-GSC 189,"AP600 SSAR inadvertent ECCS Analysis," Revision 2, assumed the need of operator actions in the analyses of increased RCS inventory events, but failed to address:
The availability of (1) unambiguous alarms or indications for increased RCS inventory events, and (2) clear procedural instructions to operators to take appropriate actions within the time-frame assumed in the analyses.
10 CFR 50.36, " Technical Specifications," Q50.36(c)(2)(ii)(C).
Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) to verify the e pacity of the system including the RV head vent valves that would be used by operators to prevent prassurizer overfill from occurring as assumed in the analyses.
Standard Safety Analysis Report (SSAR) text providing detail of the analyses that credited the requisite operator actions.
- 2. SSAR GSC-188,"AP600 Boron Dilution Analysis," Revision 0, relied on the boron mixing testing data documented in EGG LOFT 5867 (Project No. P 394) to establish the required RCS circulation flow rate of 1000 gpm in TS 3.4.9 and to support its complete boron mixing modal assumed in the boroa dilution analyses (SSAR 15.4.6). However, despite significant differences between the AP600 design and the test facility configuration and testing conditions discussed in EGG LOFT 5867, SSAR-GCS-188 failed to recencile the applicability of the boron mixing testing data to the AP600 design or to validate the complete boron mixing model assumed in the boron dilution analysis.
- 3. SEC APS-4838-CO," Software Design Specifications of AP600 NOTRUMP User Externals Cycle 2," Revision 0, dated September 9,1995, contained a statement that numerous errors in code parameters were reviewed as insignificant and would be corrected in a later code version however, no basis was given to support 'his conclusion.
- 4. SEC-APS 4837-CO," Software Change Specification of NOTRUMP Cycle 32," Revision 0, dated September 9,1995, contained a statement that "...the author doesn't know enough about the subject (void propagation) to determine the impact of the reviewer's comments." No evidence existed to support resolution of the reviewer's comrnent.
- 5. SEC-APS-4746-CO,"_WCOBRA/ TRAC Long-Term Cooling," provided no basis for concluding that " .. variations in the initial conditions are expected to have relatively unimportant effects on the analysis results," and "the results of changing ICHP is noticeable but not large..."
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- 6. LTCT T2C-417,"WCOBRAfrRAC Geometrical input Data for the OSU Testing,"
Revision 0, and LTCT-T2C 418, *OSU LTC Comparisons with WCOBRA/ TRAC,"
Revision 1.
LTCT T2C 417. Pages 180-181 (Figures 6 and 7) acknowledged the fr!Iure to fit DP vs (flow)", however, the basis provided was that "...despite the failure to match, overall agreement is reasonable." This unquantified anomaly was used as input to calculation LTCT-T2C-418.
LTCT T2C 418. On page 16, a bias of 0.2 psia was applied to the atmospheries pressure to compensate for the disparity in DP vs (flow)2 in calculation LTCT T2C-417. However, the calculation did not provide an explanation for the use of this bias.
- 7. SSAR GSC-356,"Two-Inch Break LOCA, LTC," Revision 0, presented a solution of DP vs. flow in which the author observed that a harrnonic oscillation was built-in to the solution, and therefore, he proposed to take the average value. However, the inspection team could not determine if the average value was equal to the asymptotic solution had the oscillation not been present. The calculation also did not address the impact of oscillation in the asymptotic solution, the impact of the oscillation on the flow resistance, and the presence of the oscillation in the vessel flow, DP, and vessel collapsed liquid level solutions.
- 8. SSAR-GSC-377,"SBLOCA Long Term Cooling," identified discrepancies which included a calculation for negative (reverse) DVI flow with no corresponding physical explanation provided, a two sided open break which did not agree with a two-inch pipe break assumed in the calculation, and discrepancies related to initial conditions assumed for -
leakage through ADS 1-3.
B. Criterion V of Appendix B to 10 CFR Part 50, " Instructions, Procedures, and Drawings,"
requires, in part, that activities affecting quality shall be described by documented instructions and procedures of a type appropriate to the circumstances, and shall include appropriate or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.
Westinghouse Procedure WP-4.19.3, " Software Error Reporting and Resolution, " requires that the impact of errors be reviewed on all work activities where the program was used during the time period the error existed and documented on an Error impact Review sheet within 60 days of receiving the error report.
The following examples demonstrate failure to comply with tue above requirements and constitute Nonconformance 99900404/97-02-02.
Contrary to the above, Westinghouse did not provide documentation to support the review and evaluation of compu:ar code errors for the following examples:
- 1. WCOBRA/ TRAC code error report for MOD 7A, Revision 1, listed an error affecting timestep control which was not evaluated for the specific case of the AP600 design.
In addition, code failures identified in AP600 calculations were not reported and tracked in Westinghouse's error tracking system.
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Over 100 codo errors associated with GOTHIC (after Vorsion 4.0) woro Idontified to 1 Westin0 house by the developer, Numerical Applications, Inc. (NAI). NAl stated to Westinghouse that some of the errors could b"oct safety dolorminations and may be reportablo under 10 CFR Part 21, Westinghouso could not provido documentation to support the review and disposition of those codo errors.
Please provido a writton statomont or explanat:an to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555 with a copy to the Chlof, Quality Assuranco, Vondor inspection, and Maintenanco Branch, Division of Reactor Controls and !! aman Factors, Offico of Nuclear Reactor Regulation, within 30 days of the dato of the lottor transmitting this Notico of Nonconformanco. This reply should be clearly markod as a " Reply to a Notico of Nonconformanco" and should includo for each nonconformance: (1) a doscription of the steps that were or will be taken to correct thoso items; (2) a description of the stops that havo r aill be taken to provont recurrence; and (3) the dates your correctivo actions and proventativo measures were or will be completed.
' Dated at Rockville, Maryland This pd day of January,1998 f
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