IA-81-223, Forwards Evaluation of Sacrificial Shield Wall Hardship Exemption Request.Nineteen of 21 Weld Joints Should Be Accepted as Is W/O Further Repair.Weld W3-92 Should Be Repaired & W130-197 Should Not Be Accepted

Forwards Evaluation of Sacrificial Shield Wall Hardship Exemption Request.Nineteen of 21 Weld Joints Should Be Accepted as Is W/O Further Repair.Weld W3-92 Should Be Repaired & W130-197 Should Not Be Accepted

ML20213D588
Person / Time
Site:	Columbia
Issue date:	03/23/1981
From:	Pawlicki S Office of Nuclear Reactor Regulation
To:	Youngblood B Office of Nuclear Reactor Regulation
References
CON-WNP-0343, CON-WNP-343, FOIA-81-223 NUDOCS 8103270790
Download: ML20213D588 (5)

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E 31981 Docket No. 50-397 e -

C ggg24Q MEMORANDUM FOR: B. J. Youngblood, Chief Licensing Branch #1 I.gcpBf n -p 7/ -

Division of Licensing s N

b FROM: S. S. Pawlicki Chief Materials Engineering Branch Division of Engineering

SUBJECT:

WASHINGTON PUBLIC POWER SUPPLY SYSTEM (WPPSS) NUCLEAR PROJECT NO. 2. SACRIFICIAL SHIELD WALL HARDSHIP EXEMPTION REQUEST (WELD REPAIRS)

Plant Name: Washington Nuclear Project No. 2 (WNP-2) \ '

Suppliers: General Electric, Burns and Roe Docket Number: 50-397 Responsible Branch and Project Manager: LB #1; M. D. Lynch Reviewer: D. E. Smith Description of Task: Evaluation of Sacrificial Shielf. Wall Corrective Action Plan '

Review Status: Applicant's Response Required The Materials Engineering Branch, Materials Applications Section, Division of Engineering, has reviewed the WNP-2 Hardship Exemption Request to allow some of the present weld defects in excess of the American Welding Society's Dl .1 to remain as is without repair. The 15 weld defects characterizing 21 weld joints for which hardship exemption requests were submitted were individually evaluated. We recomend that 19 of the 21 weld joints be accepted as is without furthur repair, one joint should be repaired, and the remaining joint probably should be allowed to remain as is, but an acceptable rationale was

not provided by the applicant.

l The weld joint which should be repaired is identified as Weld No. W3-92 in

! WPPSS letter G02-81-29 of 20 February 1981. The weld which we cannot make I a recomendation to accept is identified as Weld No. W130-197. This is an underfilled overhead fillet weld of small dimensions (3/8 inch underfilled 1/16 inch). No rationale was submitted which addressed the requirement for a 2.1 safety factor. We are inclined to agree with the applicant that a 3/8 fillet weld reduced in size by this small amount is of insignificant concern.

Nevertheless, it represents a 20% reduction in area or load carrying capability and apparently would not meet Dl.1 requirements.

Contact:

D. E. Smith M j.S stosesG92 .I 7

circ p ysero w m e e w c. er" OFFICIAL F:ECORD COPY e e-a m

. .e- .. r- Tv nrr n~ v 9- e # &m - 8F & F e' B. J. Youngblood MAR 2 31981 A rationale for our acceptance or rejection of each weld joint defect is provided in the attachment. Weld W130-197 should be repaired unless additional justification is submitted to support a conclusion that it is adequate in its present condition.

Enclosure:

As stated S. Pawlicki, Chief Materials Engineering Branch Division of Engineering cc: R. Vollmer V. Noonan R. Tedesco S. Pawlicki W. Hazelton J. rsnight J. Henderson M. Lynch D. Smith F. Schauer DISTRIBUTION:

CENTRAL FILE MTEB READING FILE MTEB WPPSS FILE t-3/11/81 __ [\

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ATTACHMENT 1 Washington Public Power Supply System Nuclear Project No. 2 '

l. The weld repair exemption requests are addressed in the order submitted.

Welds in the first grouping numbered (1) through (5) were evaluated by their visual inspection results only. The second grouping numbered (1) through (10) for 16 individual welds were evaluated by their ultrasonic and visual inspection results.

A. First Grouping (1) Weld No. W130-147 The 1/16 inch underfill on a 3/8 inch fillet weld reduces the cross-sectional area of the weld approximately 20%. Considering the 21/2

, inch thicknes; of the material at the defect, the use of a 3/8 inch fillet demons,trates low loads. The description of the joint is not complete, and an accurate analysis should still be made.

We recommend the applicant furthur justify his request as he did not provide a technical rationale for not meeting code requirements.

(2) Weld No. W3-92 We recommend that this weld be repaired. The depth of the pores are 1/3 the thickness of the weld. We have only surface examination results and the true extent of porosity is probably much more extensive than indicated.

(3) Weld No. WF23-87 The localized underfill would have no effect on structural load capability and the overlap condition represents excess weld metal.

We recommend acceptence of this waiver request and not require repair.

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(4) Weld No. WF-130-119 Overlap represents excess weld metal and does not reduce load carrying capability of the structure. We recommend acceptance of this waiver request.

(5) Weld No. W23-24 The pores are very small and should not reduce the load carrying capability of the structure. Recommend acceptance of this waiver request.

B. Second Grouping We recommend acceptance of waiver requests for all welds in this grouping. The defects found are what would be expected of a structure b'uilt to visual standards and then inspected by ultrasonic methods.

The AWS Dl.1 code is formulated to design on the basis of such defects being present in structures covered by the code. In addition, the defects found would not be a cause for failure of a structure, but would probably fail upon gross plastic failure of the entire structure.

(1) Weld No. W4-65 The configuration of the structure is such that it is almost impossible to create a bending tension load at the root indication to cause failure of the joint. For other loads, the proximity'of of thinner sections precludes this joint being weaker than the members which make it up.

(2) Weld No. Wil3-4 and Wil3-6 The location of the indications at the neutral axis of the stiffening member preclude any tension stresses under expected load conditions on the flaws. Thus, there is no load capability reduction of the structure caused by granting this waiver request. .

(3) Weld Nos. Wil3-12 and Wil3-14 Same as (2) above (4) Weld No. W102-ll7 The ultrasonic indication is not in the strength member, but in the backing bar which is present to allow for welded fabrication.

Accordingly, there is no concern for loss of load carrying capability of the structure.

(5) Weld Nos. Wil4-6 and W114-4 See (2) above (6) Weld Nos. Wil4-12 and Wil4-14 See (2) above.

(7) Weld No. W145-29 Joint configuration is such that bending tensile stresses can not occur at the defect location until gross plastic failure of the structure is already occurring. Accordingly, structural load I,

carrying capability is not impaired.

(8) Weld No. W145-23 See (7) above.

(9) Weld Nos. W113-28 and Wil3-30 See(2)above.

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(10) Weld Nos. W113-20 and W113-22 See (2) above.

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