ML20147F470

Forwards Relief Request 2NR15 & Interim Rept, Evaluation of Indication in Unit 2 Loop 1 Elbow to Valve Weld Region, for Review & Acceptance in Conjunction W/Review of Sc Hunsader to TE Murley on Preservice Insp Program

ML20147F470
Person / Time
Site:	Braidwood
Issue date:	02/23/1988
From:	Hunsader S COMMONWEALTH EDISON CO.
To:	Murley T Office of Nuclear Reactor Regulation
Shared Package
ML20147F474	List: ML20147F470 ML20147F484
References
4256K, NUDOCS 8803070355
Download: ML20147F470 (4)

Text

r. . - .-

, n - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - = - - - - - - - - - - - - -

'_. b 1 ?; One Fwst Nabonel Plaza, Chcego, minois -

.(_

~

'" Address Ror$ to: Post Omoe Box 757 -

's Chcego,Iginois 80000 0767 February 23, 1988 l[

~

a. i

!Mr. Thomas E. Murley, Director '

' Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Comunission Washington,'DC. 20555 .

~

tAttn: Document Control Desk

Subject:

. Braidwood Station Unit 2 preservice Inspection (PSI) Program NRC Docket No. 50-457 Reference . (a) September 23, 1987 S.C. Hunsader litter to T.E. INrley '

(b) November 20, 1987 S.C. Hunsader letter to T.E. Murley

Dear Mr. Murley:

Reference (a) provided you with the Braidwood Unit 2 PSI program. l

-Reference (b) provided a new Note #8 which had been written to address the l f

indication in the elbow to isolation valve weld, field weld 2 RC-01-04 (Line' 2RC01AA-29). t l

At this time, Commonwealth Edison has reappraised its position with ,

respect to this item and is providing a different basis for acceptance of the indication. As a result, Note #8 becomes no longer necessary and is being replaced by Relief Request 2NR15 Rev. 0 (Attachment "A"). As such, Reference (b) is being replaced by this letter.

Relief Request 2NR15 provides a description of t'se item and the justification for acceptance of the indication. Also Attachment "B" provides the interim report on the analysis performed in accordance to ASME Section XI, paragraph IWB-3600 as described in the relief request. A final report to be submitted in mid-April, 1988 will contain a more detailed description of the methodology, calculations and results. However, the interim report does envelope the analysis that will be performed in the final report and is considered to be conservative. The results to be reported in the final report are expected to be the same as those reported

-in this interim report except for the fatigue crack growth analysis. The final report will contain a fatigue crack growth based on flaw specific location-(i.e. at the inlet elbow weld location as opposed to the nozzle safe-end location considered in this interim report.) The fatigue analysis of the indication at the elbow weld location is expected to result in lesser crack growth than reported here. As such, the conclusion with respect to the acceptability of the flaw for the requirements of Section XI will not change.

6803070355 800223 PDR ADOCK 05000457 5 \

E &

= .

2--

These are being provided~to the NRC for your review and acceptance in conjunction with your review of Reference (a). Please address any ,

question concerning this matter to this office.

Very truly yours,-

, .{f S. C. Hunsader-Nuclear Licensing Administrator

/klj cc: S. Sands ,

NRC Region III Braidwood Resident Inspector 4256K ,

4 f

i k

I t

-my; Rev.-0.

BTTACHMENT A u Relief Request'2NR15 1.- SYSTEM: Reactor Coolant-

2. NUMBER OF ITEMS: 1 Line Numb _er_ . Weld Number 2RC01AA-29" 2 RC-01-04

3. ASME Code Class: 1

4. ASME Code.Section XI Requirements:

Table IWB-2500-1, Examination Category B-J, Item B9.11 requires volumetric examinations to meet the acceptance criteria contained in 1WB-3500.

5. Basis for' Relief:

'The Section XI preservice, ultrasonic examination of the above listed weld revealed an indication which exceeded IWB-3500 acceptance standards. Braidwood Station is requesting permission to apply the "Evaluation Procedures and Acceptance Criteria for Austenitic Piping" (IWB-3640) described in the 1983. Edition of Section XI, Winter 1983 Addenda.

6. - Auemented Inspections:

Braidwood Station is proposing to follow the successive inspection requirements established in IWB-2420 which requires that.the area containing the flaw be reexamined during the next three inspection periods. If the reexaminations reveal that the flaw indication has remained essentially unchanged for three successive inspection periods, the weld examination schedule may revert to the original schedule for successive inspections.

7. Justification:

The structural integrity of this weld is assured by:

a) Having performed an acceptable Section XI flaw growth analysis which has shown the maximum expected size for this flaw, for a 40-year evaluation period, is less than that given in the allowable flow size tables of IWB 3600, b) Having performed an acceptable Section III radiographic examination.

l L

c) Having performed acceptable inner surface and outer surface dye I penetrant examinations.

d) performing augmented ultrasonic examination of the flawed area

'for the next three inspection periods.

i 4256K i

f I

t I

i I

I I

t I

i f

t-i f

4 1 [

l t

I'

. . _-- - , _ , - .- . - . .