TXX-9129, Supplemental Deficiency Rept CP-87-133 Re Deficient High Energy Line Break Analysis.Initially Reported on 871218. Provides Status Od Corrective Actions & Preventive Action for Deficiency Followed by Brief Discussion

Supplemental Deficiency Rept CP-87-133 Re Deficient High Energy Line Break Analysis.Initially Reported on 871218. Provides Status Od Corrective Actions & Preventive Action for Deficiency Followed by Brief Discussion

ML20082U676
Person / Time
Site:	Comanche Peak
Issue date:	09/16/1991
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CP-87-133, TXX-91292, NUDOCS 9109200295
Download: ML20082U676 (3)

Text

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Log # TXX 91292

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C File # 10110 7t/HF~C~ 7RlC 903.6 Ref. # 10CFR50.55(e) l September 16, 1991

%imem J. cahill Jr.

I'mune Vue brMeet I

l V. S. Nuclear Regulatory Commission  ;

Attn: Document Control Desk Washington, D. C. 20555

$UBJECT: COMANCHE PEAK STEAM ELECTRIC STA110N (CPSES) - UNIT 2 DOCKET NO. 50 446 HIGH ENERGY LINE BREAK ANALYSIS SDAR CP-87 133 (SUPPLEMENTAL REPORT)

Gentlemen:

On December 18, 1987 TV Electric orally notified the NRC of deficiencies involving the high energy line break (HELB) analysis determined to be reportabic under the provisions of 10CFR50.55(e). TU Electric's evaluation of these deficiencies concluded that the combination of deficiencies represented a significant inadequacy in the performance of the original HELB analysis. The last report on this issue. TXX 89154 dated March 23. 1989, stated that the status of the Unit 2 corrective action would be updated after Unit 2 activities resume. This report provides a status of the Unit 2 corrective and preventive actions for this it. sue followed by a brief discussion of the SDAR's which were previous 1) cob'olidated s under this issue.

A Unit 2 procedure has been issued to define interfaces and responsibilities for pipe rupture (PR) engineering activities. Consistent with Unit 1. the design basis document (DDD.1 and FSAR commitments remain the basis for the HELB program. The validated Unit I calculations will be reviewed for applicability to Unit 2 by similarity. Additional calculations will be generated if necessary 'In accordance with the requirements of the DLD.

Target Identification surveys will be performed for Unit 2 to identity safety related targets affected by HEl.B's. These surveys will be controlled by an l Engineering Assessment Procedure (EAP) and will provide equivalent information/ criteria to determine the rene of influence (201) consistent with the design basis documents. 201 sketches will be used if the complexity of the pipe whip or jet survey is judged to warrant additional aids. Safe shutdown logic diagrams, environmental analyses, and essential equipment I lists will be developed or verified to be similar to those developed for Unit l 1.

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.+ TXX 91292 Page 2 of 3 A brief discussion of the six SDARs previously consolidated under this issue and the Unit 2 status is as followst MAR CP-85-20 Coplainm_ent_SpnyltidstLt f.itdnitr.llatJttoA This issue involved the resolution of jet impingement and pike whip <

interactions that were not identified in the initial Unit 1 analysis. l The initial Unit 1 analysis concluded that no protection was required <

between the six inch branch feedwater line and the three inch containment spray header. Subsequent field validation and analysis concluded that protection was required.

For Unit 2. the identification and resolution of the jet impingement and pipe whip interactions such as the one noted above are included in the Unit 2 target identification surveys described in the body of this Intter.

.SDAR Cff&4Lf t h3Me 5tudy_hals1110_ql)[titJ.nsb.nRL?_AnAlYI.td.fiDlH2 This issue involved the failure by Westinghouse to identify n i longitudinal-break to TV-Electric for resolution of potential interactions. Detailed analysis of the potential break location ,

indicated that no break was required to be postulated.

The Unit 2 project procedure defines the interface responsibilities for break Iccatfon identification. The piping analysis groups define break locations in seismically analyzed piping and transmit the break locations to the Pipe Rupture Group for evaluation. For non-seismically analyzed ,

piping. the~ Pipe Rupture Group postulates breaks in eccordance with FSAR Section 3.60.2.1.20.~

HAftfP 86-13 Jet Irpingengat Lagtftgyjn This issue involved an error which was identified in the input instructions for the Gibbs end Hill ccmputer program PIPSCIN concerning jet impingement load definition. _ This_- error invalidated part of the jet impingement-load' review previously' performed for Unit 1. This error was revealed and corrected for the-Unit I analysis. -

The. Unit 2 Pipe Rupture Group does not usc the PIPSCIN computer code which is the subject of this SDAR. Jet impingement loads are defined in accordance with the methodology of ANSI /ANS 58.2 1988.  ;

-I SDAR CP-87-53 P,jp.e-Whin Restraint Desian Hg1hadoloay This issue involved the methodology used in developing P!PERUP computer

models. In particular, these models did.not justify time steps and l arbitrary anchors and did not consider pre-steady state wave _ forces.

The Unit 2 pipe whip restraint design adequacy is verified by either reanalysis or a similarity review for applicability to the validated Unit 1 calculations. The reanalysis models consider, as appropriate. time -

steps, arbitrary anchors and pre

• steady state wave forces.

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. TXX 91292 Page 3 of 3 10ALCfr.ShS7 CmPr.Lerlede.11aalr. tor t.10tWBLat0.UA This issue involved modeling errors for tornado damper analysis in the computer program COMPAkt H0D 1A. In particular, the version of the code used had a " variable area door" option which atsumed that the damper opens at a set pressure and relatches when the pressure falls below the set presstre. 1ornado dampers installed at CP5ES do not relatch when h pressure drops below the set pressure.

The revised and validated Unit I calculations will be verified for use in Unit 2. Where new calculations are required, the corrected edition of COMPARL MOD 1A will be utilized. It should be noted that the Unit 1 Systems Intera: tion Program was responsible for tornado unalysis. This

] cope of wort has since been transferred to Unit 2 Hechanical Engineering and will continue to be tracked as part of SDAR CP 87-133.

EME._CP 81_33 C.QMuder tiqdelino Error ML ALJ This issue involves errors found in the Gibbs and Hill version cf the RELAP 3 computer program used in the Unit 1 HELO analyses. This program was used to calculate blowdown forces generated during an HELO. These errors indicated that the forcin; function input could be lower than actual calculated values and resalt in non conservative pipe whip restraint designs. Unit i reviewed and corrected this analysis.

The Unit 2 PR Group does not use RELAP 3 computer code nor any previous analysis based on RLt.AP 3. DetaileJ thermal / hydraulic analyses to determine blowdown forces are performed using RELAP 5 or are based on detailed comparison of Unit 2 conditions to validated Unit 1 analyses based on REL/.P 6.

All actions to resolve the HELD issues and tornado damper analysis will be completed prior to Unit 2 fuel lord.

Sincerely, ,

a b / A William J. Cahill. Jr.

RJB/bm c - Mr. R. D. Hartin, Region IV Resident inspectors. CPSES (2) h

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