ML16139A468
| ML16139A468 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/21/1995 |
| From: | Grundrum L NRC (Affiliation Not Assigned) |
| To: | Marcus G NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9507310190 | |
| Download: ML16139A468 (4) | |
Text
OAD REGTjO 0
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 21, 1995
!0ORANDUM TO:
Gail H. Marcus, Director Project Directorate 111-3 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation FROM:
Linda L. Gu d je' V B&WOG Project Directorate 111-3 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation
SUBJECT:
TELECON RE: TOPICAL REPORT BAW-2228 REVISIONS AND THEIR EFFECT ON OCONEE UNIT 3 A conference call was held on June 28, 1995, with the following NRC, B&W Nuclear Technologies (BWNT), Duke Power Company, and the BWNT Owner's Group personnel listed in the Attachment. The purpose of the conference call was to discuss a June 12, 1995, letter to the NRC from Duke Power Company.
The safety evaluation issued December 2, 1994, and incorporated into BAW 2228A, "Fracture Mechanics Assessment of Postulated Outer Surface, Semi elliptical Circumferential RV Nozzle-to-Pipe Weld Flaws," stated that "each licensee that references this topical report as the basis for the request for relief from the external surface examination of RV nozzle-to-piping welds must confirm plant specific applicability by demonstrating that (1) the input stresses shown in Table 1 for its plant are a result of using the bounding transient analysis and (2) the material in its inlet, outlet, and core flood nozzles is the same as those stated in the B&W topical report."
During Oconee Unit 3's review two areas of possible nonconservatism were identified.
The safe end to piping stresses did not consider piping thickness which may be thinner than the nozzle wall.
Secondly, the effects due to dynamic LOCA and SSE loads may not be conservative for a specific plant design.
As part of the reevaluation to address these two items, the fracture mechanics stress intensity factor (SIF) solution was revised to remove some conservatism. This SIF solution will be included in a revised submittal of BAW-2228 after receiving peer review by the B&WOG reactor vessel working group. This should take approximately 4 weeks.
For Oconee, the previous relief request required either performing the code required examination or getting a fracture mechanics analysis submitted, reviewed, and approved. Since neither option can truly be accomplished until the revised topical report is submitted, the NRC requested the following for Oconee, Unit 3:
submit a relief request that will include a preliminary description of the revised fracture mechanics SIF solution and provide Oconee specific numbers for the maximum allowable flaw depth as a function of wall thickness for both the methodology used in BAW-2228A and in the proposed revision for the core flood nozzle.
9507310190 950721 U
PDR ADOCK 05000287 P
G. Marcus 2 -
July 21, 1995 The NRC also asked if Arkansas Nuclear One was effected by these changes.
In a followup call on June 29, 1995, between BWNT, ANO, and Linda Gundrum, NRC, ANO personnel stated that one additional operating cycle exists before they submit a relief request. They plan to reference the proposed BAW-2228A, Revision 1.
The revised BAW-2228 will be submitted after it has received BWNT Owner's Group review. No specific date was discussed.
Docket No. 50-287
Attachment:
As stated.
cc:
Conference Call Participants Distribution Docket File PUBLIC PD3-3 Reading WRussell/FMiraglia RZimmerman JRoe OGC EJordan ACRS (4)
GTracy, RII BMcCabe, RIII DOCUMENT NAME:
G:\\BWOG.TEL To receive a copy of this document, indicate in the box: "C" = Copy without attachment/enclosure "E" = Copy with attachment/enclosure "N" = No copy
- See previous concurrences OFFICE LA:PD3-3, LL PM:PD3-3 E EMEB PD2-3 E ECHB PD3-3:PD NAME DFoster-Curseen LGundrum:bM ETSullivan*
LWiens*
SSheng* GMarcusEff DATE 7/,4/95 1(] 7/2/95 7/17/95 7/17/95 7/17/95 7/a)/95 U
OFFICIAL RECORD COPY
July 21, 1995 The NRC also asked if Arkansas Nuclear One was affected by these changes.
In a followup call on June 29, 1995, between BWNT, ANO, and Linda Gundrum, NRC, AN0 personnel stated that one additional operating cycle remains before they submit a relief request. They plan to reference the proposed BAW-2228A, Revision 1.
The revised BAW-2228 will be submitted after it has received BWNT Owner's Group review. No specific date was discussed.
Docket No. 50-287
Attachment:
As stated.
cc:
Conference Call Participants
CONFERENCE CALL PARTICIPANTS Tony Robertson, BWNT Frank Gregory, BWNT Larry White, BWNT Ashok Nana, BWNT Bob Borsum, BWNT Linda Gundrum, NRC Gene Navortil, GPU Ted Sullivan, NRC Len Wiens, NRC Simon Sheng, NRC Don Gulling, Florida Power Corporation Attachment