ML20006G010

Discusses 900110 Meeting W/Nrr Re 13R Insp Criteria for RWCU Welds Outboard of Second Containment Isolation Valve. All Welds Required 100% Radiography Based on Review of Piping Spec.Response to Generic Ltr 88-01 Will Be Revised

ML20006G010
Person / Time
Site:	Oyster Creek
Issue date:	02/21/1990
From:	Devine J GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
5000-90-1891, GL-88-01, GL-88-1, NUDOCS 9003010472
Download: ML20006G010 (2)

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GPU Nuclear Corporation M laa, one upper eone no.a EW swMu - Parsippany, New Jersey 07054 201 316-7000 TELEX 136-482 Writer's Direct Dial Number; February 21, 1990 5000-90-1891 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Hail Station P1-137-Washington, D. C. 20555 Gentlemen:

Subjects Oyster Creek Nuclear Generating Station (OCNGS)

Docket No. 50-219 IGSCC Inspection Plan - RWCU References (1) NRC Ltr., dated 2/16/89 (2) GPUN Ltr. 5000-88-1605, dated 8/1/88 (3) GPUN Ltr. 5000-89-1838, dated 11/16/89

.On January 10, 1990, GPU Nuclear (GPUN), and NRR discussed the 13R inspection criteria for the Reactor Water Cleanup System (RWCU) welds outboard of the second containment isolation valve. Briefly, our plan (Ref. 3) was to perform during the hydro test a visual check of the welds outboard of the second valve and to ultrasonically (UT) examine these welds only in the event of IGSCC being detected in the more susceptible welds inboard of the second valve. The Staff agreed with our man-rem concerne for the inspections, but did not concur with the inspection plan as proposed. The Staff requested that GPUN review the fabrication records to determine whether the welds between the first and second [

valves, were radiographed during construction. If these welds were fabricated l to the same criteria as the outboard welds, then GPUN could classify these welds as representative of the IGSCC susceptible welds' outboard of the second valve. UT of these welds between the valves, with an additional 10 welds

, outboard of the second valve, would provide a representative sample for the 13R IGSCC inspections. i

)

In response to the staff request, GPUN has reviewed the piping specification for the RWCU system, and has determined that all welds required 100%

l radiography. Further, the piping and welds inboard of'the first isolation valve l were fabricated to ASME Section I, 1965 edition, and the piping and welds i beyond the first valve were fabricated to ASA B31.1, 1955 edition.

Based on these facts, our original proposal (Ref.3) has technical merit. The RWCU welds within the IGSCC boundary are differentiated by their operational  ;

j. stresses. For example, those welds residing inboard of the second valve have a j

higher propensity for IGSCC than those outboard of the second valve, because the operational stresses are higher by a factor of two.

9003010472 900221 PDR D

D l O- ADOCK 05000219 PDC h RWCU pooi GPU Nuclear Corporation is a subsidiary of General Public UtMes Corporation

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U.S. NuclOtr R gulctory CommiC0 ion Page.F However, in response to the Staff's generic concern for RWCU welds outside of the second valve, GPUN has opted to include 10 (approximately 10%) of the welds outboard of the second valve in the initial 13R UT inspection sample. If

' indications are characterized as IGSCC in this inspection sample, GPUN will approach the staff on their disposition and any plans for sample expansion.

If no indications of IGSCC are found outside of the second isolation valve during 13R, there would be additional technical justification for our original plan (Ref. 3). We would then reinstate this inspection plan after the 13R outage. Therefore for pont 13R required RWCU weld inspections,-a visual check would be preformed during the hydro tost of the weldc outboard of the second isolation. valve. UT examinations would be performed for those welds only in j the event of IGSCC being detected in the more susceptible welds inboard of the second valve. For the IGSCC detected within the welds inboard of the second isolation valve during examination of the initial inboard sample, a maximum of 10 percent of the welds outboard of the second valve that reside within the IGSCC boundary would be examined. ,

l This letter supercedes our previous inspection plan (Ref 3) for the RWCU welds outboard of the second isolation valve. In order to preserve the OCNGS IGSCC inspection plan within one source document, GPUN will submit a revision to our previous GL88-01 response. This document will include this change to our RWCU inspection plan and outline the revised piping replacement plans for the 13R outage. If you have any questions, please contact Mr. Michael Laggart, Manager, BWR Licensing, at (201) 316-7986.

Very truly yours, C. DeVine,Jr.W J.

Director Technical Functions JCD/DGJ/cjg cc: Mr. William T. Russell, Administrator Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, N.J. 08731 Mr. Alex Dromerick U.S. Nuclear Regulatory Commission Mail Station F1-137 Washington, D.C. 20555 RWCU

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