05000293/LER-1982-005, Forwards LER 82-005/01T-0.Detailed Event Analysis Encl

Forwards LER 82-005/01T-0.Detailed Event Analysis Encl

ML20042A736
Person / Time
Site:	Pilgrim
Issue date:	03/12/1981
From:	Machon R BOSTON EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20042A737	List: 05000293/LER-1982-005, Forwards LER 82-005/01T-0.Detailed Event Analysis Encl 05000293/LER-1982-005-01, /01T-0:on 820226,deficiencies in Pipe Supports in Control Rod Driveline Insert & Withdraw Lines Identified. Caused by Missing or Loose Clamps.Restoration to Acceptable Limits Will Be Completed Before End of Cycle VI
References
82-77, 820312-01, 820312-1, NUDOCS 8203230728
Download: ML20042A736 (3)

LER-1982-005, Forwards LER 82-005/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2931982005R00 - NRC Website

text

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4MT09 IM)lt cotara*r PILDRIM NtaCLEAR POWER STATION RFO #1 Rocky HILL ROAD PLYMauTH. M A S 3 A C H U S E TIS O2360 R. D. Ms. ADH muc6ea. oesmatio e mawatese

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March 12, 1982

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,.g BECo Ltr. #82-77 g Director, Region I

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Office of Inspection and Enforcement 7

U. S. Nuclear Regulatory Commission L.

/n 631 Park Avenue

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King of Prussia, PA 19406 Docket Number 50-293 License DPR-35 Gentlement:

The attached Licensee Event Report 82-005/015-0 " Pipe Supports" is hereby submitted in accordance with the requirements of Pilgrim Nuclear Power Station Technical Specification 6.9.B.l.i.

If there are any question on this vibject, please contact us.

Respectfully submitted, 8

R. D. Machon Nuclear Operations Manager Pilgrim Station GGW:ko Enclosure: LER 82-005/01T-0 i

cc: Document Control Desk l

U. S. Nuclear Regulatory Commission l

Washington, D. C.

20555 1

l Standard BECo LER Distribution l

8203230728 820312 PDR ADOCK 05000293 S

PDR L

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U BOSTON EDISON COMPANY PILGRIM NUCLEAR POWER STATION DOCKET No. 50-293 Attachment to LER 82-005/01T-0 During the current refueling Outage, BECo conducted a field survey of the Control Rod Drive Hydraulic Insert and Withdraw lines.

This field survey noted the following deficiencies:

1.

Four seismic supports not completely installed.

2.

Several pipe clamps on the insert and withdraw lines were missing or loose.

3.

Several braces on pipe supports were not installed.

Most of the deficiencies were inside the Drywell. Outside the Drywell the major apparent deficiency was missing or loose clamps. Bechtel was consulted immediately in order to determine if these were indeed deficiencies, what effect they had on system safety and how they should be corrected.

The lines are 304SS, 1" fill and 3/4" withdrawal. Design is B31.1 with FSAR Seismic Class 1 requirements. These would limit operational stress to 1.20 Sh (19320 psi) and maximum stresses during an SSE to yield stress (20700 psi).

Design of piping inside the Drywell was made using a computer piping code and out-side the Drywell by the rigid span method.

After discussion of the problem with Bechtel and onsite consultation with their piping analyst, Bechtel concluded that all lines within the Drywell were above the FSAR allowable stress limits, but all, except eight, were within present day faulted code allowables of 2.443 The eight pipes (5 fill and 3 withdrawal) out-side code allowable will be restored to the same condition as all other pipes in-side the Drywell (above FSAR but within code allowable and operability limits).

This will be done by restoring the eight missing or loose clamps prior to startup.

The piping outside the Drywell is being restored to original design condition by replacing and tightening pipe clamps as needed, using criteria given by Bechtel.

The following discussion documents the analysis methods used and the basis for the acceptance of the piping inside the Drywell with stress limits above FSAR but below present day faulted allowables and operability limits.

The evaluation of the as built configuration of the CRD insert and withdraw lines was performed by Bechtel. A computer analysis using Bechtel program ME101 (for details see Bechtel Topical Report BP-TOP-1) was performed assuming that the de-ficiencies noted were not corrected except for the repair of the eight missing or loose pipe clamps. The analytical results were transmitted to BECo in Bechtel letter BLE 1216 and BLE -1206.

The results showed that the peak calculated stress was 30,210 psi which is above the FSAR acceptance limit.

In order to justify continued operation the methods developed for BECo's work on NRC IE Bulletin 79-14 was implemented. A description of this analysis was sub-mitted to the NRC via BECo letter 79-175.

This letter required a review to an acceptable operability stress limit developed based on piping codes ANSI B 31.1 and ASME B&PV Section III.

The operability limit developed for Bulletin 79-14 was 2.4 S.

For the CRD piping this value is 38,640 psi.

As can be noted the h

stress value calculated for the as built condition meets this operability limit.

l As required by our submittals on Bulletin 79-14 the piping system must be modi-l fled to meet the FSAR limit. The modifications have been designed by Bechtel l

and attached to BLE-1216. These modifications will be completed prior to j

startup from the next refueling outage.

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