05000280/LER-1979-004-01, /01X-1 on 790309:notification Received of Possible Errors in Pipe Stress Code Analyses in Some Facility Piping Sys.Inaccurate Value Weights Were Also Identified. Plants Are Shut Down Pending Evaluation

/01X-1 on 790309:notification Received of Possible Errors in Pipe Stress Code Analyses in Some Facility Piping Sys.Inaccurate Value Weights Were Also Identified. Plants Are Shut Down Pending Evaluation

ML18116A271
Person / Time
Site:	Surry
Issue date:	07/31/1979
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18116A270	List: 05000280/LER-1979-004-01, /01X-1 on 790309:notification Received of Possible Errors in Pipe Stress Code Analyses in Some Facility Piping Sys.Inaccurate Value Weights Were Also Identified. Plants Are Shut Down Pending Evaluation
References
LER-79-004-01X, LER-79-4-1X, NUDOCS 7908030456
Download: ML18116A271 (4)

LER-1979-004, /01X-1 on 790309:notification Received of Possible Errors in Pipe Stress Code Analyses in Some Facility Piping Sys.Inaccurate Value Weights Were Also Identified. Plants Are Shut Down Pending Evaluation

Event date:
Report date:
2801979004R01 - NRC Website

text

NRC FORM 366 (7-77)

• UPDATED REPORT LICENSEE EVENT REPORT

-* NUCLEAR R_EGULATORY COMMISSION CONTROL Bl ')CK: I 1

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REPORTDATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES@.

. []Ji]* 1 The Architec.:..t-Engineer (AE) notified Vepco of possibJ.:.: non-conservatisms in the.:<*~

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stress code used to ar,;:ilyze some piping systems at Surry.

Inaccurate valve weights. I were also identified in some instances.

The healtt and safety of the public was not affected.

This event is reported per Technical Specification 6.6.2.a.9.

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43 REVISION 32 [II9J I In reviewing the Beaver Valley piping design, the AE discovered an error in the pipe.

stress analysis and the valve weight used to analyze stress in some piping systems.

It was found 1:hat the discrepancy also applies to Surry.

Ari. evaluation of the problem!

is underway.

Both units are shutdown awaiting the results of the re-evaluation.

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68 69 80; NAME OF PREPARER __ W_. _L_. __

S_t_e_w_a_r_t _________ _

PHONE:

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Surry Power Docket Nos:

Report No:

Event Date:

• Station,. Unit Nos.

50-280 & 50-281 79-004/0lX-l 03-09-79 UPDATED REPORT 1 & 2 Title of Report:

Pipe Stress Analysis Evaluation

1.

Description of Event

The Architect-Engineer (AE) notified VEPCO of possible non-conservatism in the pipe stress code used to analyze some piping systems at Surry.

Inaccu-rate valve weight~ were also identified in some instances.

The health and safety of the public were not affected.

This event is reported per Tech-nical Specification 6.6.2.a.9.

2.

Probable Consequences and Status of Redundant Systems:

Possible non-conservatisms are being investigated by the Architect Engineer to determine their extent and magnitude.

3.

Cause

In reviewing the Beaver Valley piping design, the AE discovered an error in the pipe stress analysis and the valve weight used to analyze stress in some piping systems.

It was found that the discrepancy also applies to Surry.

An evaluation of the problem is underway.

Both units are shutdown awaiting the results of the re-evaluation.

4.

Immediate Corrective Action

The immediate corrective action was to begin an investigation.to determine if the significance of any non-conservatisms are of sufficient magnitude to require corrective action.

Unit 2 was already shutdown for steam genera-tor repairs.

Unit 1 was shutdown pending the investigation of the di~-

crepancy.

5.

Subsequent Corrective Action:

Complete.analysis of the Unit No. 1 piping has revealed about 63 modifica-tions which must be made.

Partial analysis of the supports within these systems, which is about 50% complete at this time, has indicated thirty nine (39) support modifications are required. outlines the details of modifications completed through July 25, 1979.

6.

Future Corrective Action:

Analysis will continue and modifications will be made to assure any over-stress conditions are relieved.

Upon completion of the entire program a compiled list of all modifications made will be submitted as a followup report.

7, Generic Implications:

This event is applicable to Surry Units 1 and 2.

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UPDATED REPORT, page 1 of 2 Surry Power Station, Unit Nos. 1 & 2 Docket Nos:

50-280 & 50-281 Report No.:

79-004/0lX-1 Event-Date:

03-09-79 SYSTEM LHSI LHSI LHSI LHSI LHSI LHSI SW RHR LINE*NO.

10"-RH-16-1502 10"-RH-16-1502.

10"-RH-16-1502 10"-RH-16-1502 10"-SI-6-153 8"-SI-92-153 24"-WS-30-10 14"-RH-2-,-602 RHR 14"-irn-4-602 RHR 14"-RH-5-602 RHR 14"-RH-2-602 RHR 6"-RH-20-152

• RHR/LHSI 10"-RH-16-1502 RHR 4"-RH-15-152 RHR 4"-RH-15-152 RHR 4"-RH-15-152 CRS 10"-CS-3-153 CRS 10"-RS-13-153 CRS

.10"-RS-12-153

DESCRIPTION

Add Suppressor at Point #205 (New Hanger).

Modify VC/LC at Point #210 to VC.(Hanger H-29).

Modify VC/LC at Point #220 to VS (Hanger H-,-28).

Modify LC to VC at Point #200 (Hanger #30)

Modify Vertical Constraint to VC/LC at Point lf60.

Add Structural Braces to Support. SI-C-91.

Remove Support H-21~ to simplify calculation on existing Support (Gang Hanger) in PI;"oblem #636.

EW support overstressed at Point #85.

Add Vertical Constraint (VC).at Point #133 and delete Spring Hanger.

Add Vertical Shock Suppressor at Point #996.

Add Vertical Shock Suppressor at Point #1030.

Add Lateral Shock Suppressor at Point #130.

Delete NS-EW Restraint (U-Bolt) at Point #100.

Modify VS at Point #305 to VC.

Delete Rod Hanger at Point #32.

Delete Rod Hanger at Point lf3 7.

Delete N-S Restraint at Point #46.

Add Horizontal Shock Suppressor at Point #33.

Replace Spring Hanger at Point /1195 by Sway Strut.

Replace Rod Hanger at Point #160 by Spring Hanger H-32.

I

• , page 2 of 2 CRS CRS PSR SLER:C4 10"-RS-12-153 10"-RS-12-153 4"-RC-14-1502 Modify Supports #H29A (Prob. #562) and R29B (Prob. #546/5600) by adding Structural Members.

Add E-W Restraint at Point #140 (Hanger H-95).

Modify Anchor at Point #202 (R-36).