ML19338E246

Deficiency Rept Re Helba Restraint Design.Steady State Rather than Peak Thrust Forces Were Used in Design of Q-listed Pipe Whip Restraints.Investigation & Identification of Root Cause Recommended.Another Rept Due by 801201

ML19338E246
Person / Time
Site:	Midland
Issue date:	09/19/1980
From:	Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
References
10CFR-050.55E, 10CFR-50.55E, 8830, NUDOCS 8009250284
Download: ML19338E246 (6)

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., James W Cook

,\ Ves'e hendent, AfsJland Nujecs U-.., ..)

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General o f fices : 1945 West Parnail Road, Jickson, Michigan 49201 e 15171788 0640 September 19, 1980 Mr J G Keppler, Regional Director Office of Inspection & E.cforcement US Nuclear Regulatory Ccc: mission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND liUCLEAR PLAIIT UNIT NO 1, DOCKET N0 f 0-329 U'IIT NO 2, DCC:Cr No .30-330 HELEA RESTRAI!TI DESIGN FILE: 0.h.9.hl UFI: 73*10*01 SERIAL: 8830 This letter ecnfirms the 50.55(e) item cencerning HELEA Restraint Design, reported by telephone call to R Knop, USHRC Region III, Glen Ellyn, IL, on August 21, 1980.

The attachments to this letter describe the conditions and actions taken cencerning this it em.

Another repcrt, either interin or final, vill te sent en or before Decenber 1, 1980.

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'n'RB/1r Attachtent: 1) Management Ccrrective Action Report (MCAR-1), Report No h0, dated August 21, 1980

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2) MCAR LO, Interim Report 1, High Energy Line Break Analysis (HELBA), Pipe Whip Restraint Designs, 4.ted September 11, 1980 CC: Director of Office of Inspection & Enferee At+ Mr Victor Stello, USHRC (15)

Director of Office of Management Inflormation and Program Control, USNRC (1)

R Cook, USNRC Resident Inspector deli V [

Fidland Nuclear Plant (1) hlf 8009250 ggsj 3

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OUALITY ASSURANCE PROGRAM Attachment 1

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• MANAGEf.iENT CORRECTIVE ACTION REPORT Serial: 8830 MCAR1

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REPORT NOJ 1.102 o ,,g 8/21/80 JOBNO2 722%1H0.L ONO.: _

1 DESCRIPTION * (includ;ng References):

Contrary to the requirements of FSAR 3.6.2.2 and the referenced sections of BN-TOP-2, steady state rather than peak thrust forces were used in the design of Q-listed pipe whip restraints. Design documents have been released for construction /

fabrication purposes and most of the restraints have been installed.

l RECOMMENDED ACTION * (Optional):

1. The high energy line break analysis (HELBA) group to develop l

and provide the civil and plant design disciplines with data i necessary to perform a reanalysis of the pipe whip restraint

( designs to assure their compliance with FSAR subsection 3.6.2.2.

I REFERRED TO: Ot Engineering O Ccnstruction O OA Management O O Procurement /, g , g ISSUED BY: _ M.Q*/h idtf/h _S!d/0)

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c,, L. A. D$$i5*5IAC H '~ heIE!

lPotentially E ~

!! REPORTABLE DEFICIENCY: l Reportable NOTIFIED CLIENT:

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O NO O YES YSYf S'$pYO l

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l Ill CAUSE:

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l CORRECTIVE ACTION TAKEN:

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&APO Instatsu*gN PaOJ Otsiktf:UTICN 01Hf a Distateuttoes uGn or cossvauctc~ Cao Co% sin oc tsG= uGn Ce c4 iPo FORMAL REPORT TO CLIENT eGn er cue.ucwe cutut Gre osuGa (if Sect:enil Appiies) w= l UGH CW P90Cuatet 41 PFOct LAPO.C&uGR ,

L uGR C# PROJ OrtnatCNS PROXCT CONSTR uGR SFPQ - Q4 UG4 l uGn er cus.t. avuaa Ct enos Cte~e.stia CORHECTIVE ACTION IMPLEMENTED CCNsf RVctcs uGo peO4C1uGn ENG M i8ueG UGm PROJ PHOCuntu!Nf uGR surrtain Cuaw X.4 stig UGH c4 suctnscoa -

VER!FIED BY

• DesCnbe in $ Pace provided and attxh reference dncument P,mect on te;* c.ie u rocoe. Section Number Page of

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MCAlt 40

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RECOM.*!ENDEDAbl053Oc2itinued

2. The plant design discipline to develop and provide plastic hinge icngths for the reanalysis of the pipe whip restraint designs.

3. The civil discipline to review affected pipe whip restraint design documents, considering the peak thrust forces, to assure that they shall perform adequately during a high energy pipe rupture.

If necessary revise design documents.

4. Ibve the cognizant Chief Engineers office review the llELBA group assumptions and work processes to determine if other similar potential probic=s exist.

5 If thru the review process certain pipe whip restraints are identified as requiring codification, notify Construction, Quality Control ana' the PQAE.

This notification shou.1.d be provided as soon as practical af ter the necessary modification is identified. .

6. Investigate and identify the root cause and provide corrective action to preclude recurrence.

7. Develop and submit a written report to the PQAE for coordination with Consumers Power Compa,ny containing available infor=ation on or before 9/11/80.

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Attachment 2

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, Serial 8830

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Bechtel Associates Professional Corporation 0II918

SUBJECT:

MCAR 40 (issued 8/21/80)

High-Energy Line Break Analysis (HELBA),

Pipe Whip Restraint Designs INTERIM REPORT 1 DATE: September 11, 1980 PROJECT: Consumers Power Company Midland Plant Units 1 and 2 Bechtel Job 7220 Introduction This report is submitted regarding the interim status and actions pursuant to the subject MCAR.

Description of Discrepancy FSAR Section 3.6.2.2 states that the analysis of the thrust forces which result in the event of a pipe rupture is described in BN-TOP-2. Con-trary to the intent of BN-TOP-2, the steady-state thrust forces rather than the transient peak thrust forces were used in the energy balance techniques for the design of RELBA pipe whip restraints (see attachment, Figure B). Design documents have been released for construction /fabri-cation and most of the restraints have been installed.

Cause The cause of this discrepancy has been identified as a misinterpretation of the requirements of BN-TOP-2.

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Safety Implication

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The safety-related function of a pipe whip restraint is to limit pipe movecent following a high-energy line break to prevent unacceptable damage to essential systems or components. Designing the restraint using the steady-state thrust force instead of the higher transient thrust force could compromise this safety function. The size of the restraints may be inadequate for the increased loads, and/or their location may be inadequate as a higher thrust force may cause the plastic hinge length to decrease outside the range of the restraint. Th. deficiency, were it to have remained uncorrected, may have adversely affected the safety of operations

, at the Midland plant if certain types of accidents were to occur.

Analytical Re' valuation Action The affected restraints are being reevaluated using conservative thrust force time-histories input to energy balance and/or time history methods as described in BN-TOP-2.

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Bechtel Associates Professional Corporation Oil 918 MCAR 40 Interim Report 1 September 11, 1980 Page 2 Corrective Action Corrective action depends upon the results of the analytical reevaluation.

Forecast Dates The next interim report is scheduled to be issued by November 21, 1980.

Reportability

', This condition was reported by Constpers Power Company to the NRC as a potential 10 CFR 50.55(e) reportable condition on August 21, 1980.

A 30-day report is due to be sent to the NRC on September 20, 1980.

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Submitted by:

Approved by: El I bNtLT85 Concurrence by: / *f -

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A. Thrust Force Transient, Very Low Friction Flow

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B. Thrust Force Transient, Priction Flov

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