ML20099L122
| ML20099L122 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/15/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| ANPP-31130-TDS, DER-84-15, NUDOCS 8412010016 | |
| Download: ML20099L122 (6) | |
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ECOVED 2,',1c Arizona Nuclear Power Project PHOENIX, ArlZONA 85072-MI l,]y l g P.O. BOX $2034 e f
November 15j 1984 E
ANPP-31130 TD'S/TR3ti U. S. Nuclear Regulatory Commission hd-h Region V 1450 Maria Lane - Fuite 210 Walnut Creek, California 94596-5368 Attention: Mr. D. F. Kirsh
Subject:
Final Report - DER 84-15 A 50.55(e) Reportable Condition Relating To Welds Attaching Pipe Restraint Supports Less Than Design Calculated Dimensions In Uni
- 2.
File: 84-019-026; D.4.33.2
Reference:
A) Telephone Conversation between P. Narbut and J. Cook on March 21, 1984 B) ANPP-29285, dated April 12, 1984 (Interim Report)
C) ANPP-30071, dated July 30, 1984 (Time Extension)
D) ANPP-30479, dated September 11,1984 (Ti:se Extension )
E) ANPP-31012, dated October 30, 1984 (Time Extension)
Dear Sir:
Attached is our final written report of the deficiency referenced above, which has been determined to be Not Reportable under the requirements of 10CFR50.55(e).
Very truly yours, C(S._L_
AL t E. E. Van Brunt, Jr.
APS Vice President Nuclear Production ANPP Project Director EEVB/TRB/nj Attachment cc: See Page Two 1
l tl412010016 841115 PDR ADOCK 05000529 S
PDR l
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. Mr. D. F. Kirsch DER 84-15 Page Two cc:
Richard DeYoung;.' Director Office of. Inspection and Enforcement l
U. S. Nuclear Regulatory Commission Washington; D.-C.
20555 T. G. Woods, Jr.
D. B. Karner W. E. Ide D. B. Fasnacht A. C. Rogers L. A. Souza D. E. Fowler T. D. Shriver C. N. Russo B. S. Kaplan J. R. Bynum J. M. Allen A. C. Gehr W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher H. D. Foster D. R. Hawkinson R. P. Zimmerman L. Clyde M. Woods T. J. Bloom D. N. Stover J. D.'Houchen J. E. Kirby D. Canad;r Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, CA 30339 k
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,1 FINAL' REPORT - DER'84-15' j
DEFICIENCY EVALUATION 50.55(e)
. ARIZONA PUBLIC SERVICE COMPANY (APS)
PVNGS UNIT 2 4
'I.
Description of-Deficiency:
DesignLdrawings; specifications; and procedures do 'not fully identify all' the requirements for welding a U shaped ' pipe restraint support to the pipe pressure boundary.- Engineering calculations use a weld length equal to' one half the circumference of the pipe (180 degrees) as a basis for determinina the acceptable loading' on anchor strap restraint supports., The uesign drawings depict the pressure boundary weld to extend from 0.to 180 degrees as shown in Figure A.
Specifications 13-PM-204 and 13-PM-205 allows the substitution of a two directional guide strap for an anchor strap. The guide strap was originally designed with a 1/16" clearance between the pipe and strap as shown in Figure B.
When the strap was slightly modified 'for use as an anchor. strap; the weld joint was. reduced to an angle as small as 120 degrees as shown in Figure C.
'This substitution presents three conditions which were not addressed in the specification:
1.
The minimum length of weld required.
2.
Maximum allowable fillet weld leg size.
3 Provisions to increase the fillet leg size when the gap between the restraint and the pipe is not a formed fit-up of 0 to 1/16" clearance.
Without direction covering the above requirements, the field practice was to perform welding until approximately 1/8" gap was encountered between the~ pipe and the restraint. This practice has resulted in welds which are less than the calculated weld dimensions.
Evaluation This condition was initially documented by Corrective Action Request
.(CAR) S-84-21 which identified seven pipe restraint welds to the pipe t
l pressure boundary which were less than 180 degrees of weld.
Engineering evaluated the subject pipe supports of CAR S-84-21; also, L
at additional 261 "Q class" pipe supports (shown on 265 drawings)
L-were analyzed for minimum required weld length. This analysis incuded all. "Q class" supports utilizing anchor strap type rest raints. Based on these evaluations specific acceptance criteris
.were established to provide'an adequate weld length between the:
anchor strap and pressure. boundary.
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Final Report.
DER 84-15 Page-Two' Using these clarified criteria; Bechtel Construction reinspected all-the identified pipe supports in Unit 1.
Supports which did not meet
.these criteria were reported on NCRs PC-8523, PA-8616, PA-8617, and PX-8839.'
Engineering evaluated the conditions identified by these NCRs and found all the installations to be within acceptable loading conditions'. Calculations -13 MC-zz-003, Revision 0, was prepared to document this analysis.
'The root.cause of this condition is identified as Engineering's failure'to provide acceptance criteria covering all variations which may exist during installation of strap type restraints. QC adopted acceptance criteria. based on practice instead of having; the criteria identified in engineering design documents. Based on many previous inepections by engineering and audits by independent organizations, no other similar pipe support conditions exist.
II.
Analysis of Safety Implications Based on the above, this condition is evaluated as not reportable.
under 10CFR50.55(e) or 10CFR Part 21;'since if lef t uncorrected, it would not represent a significant safety condition.
III.
Corrective Action A.
Remedial Action The applicable supports in Unit I were reinspected as required by special procedure WPP/QCI 559.0.
Nonconforming installations were documented by NCRs PC-8523, PA-8616, PA-8617, and PX-8839.
The nonconforming installations were reviewed by Engineering and dispositioned use-as-is.
j Due to a df fference in types of straps used, Units 2 and 3 will be reinspected under specially prepared WPP/QCIs 560.0 'and 561.0, respectively. NCRs will be issued to correct any deficiencies found. These NCRs will cross-reference ~ this DER for -
reportability disposition. This work-will be completed prior to.
fuel load in-each unit.
.B.
Action to Preclude Recurrences To address the root cause, Engineering has clarified anchor strap n
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inspection criteria by revising the following design documents: '
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Final Report
,Page Three1 1
Drawing 13-S-ZAS-519,. DCNs No. 8.and No. 9 (Reference FCRs 79006-P and 79346-P)
Drawing 13-RC-081-H00G,(Reference FCR 79347-P)
Drawing 13-SI-249-H00C :(Reference FCR 79348-P)
Specification 13-PM-204;- SCN No. 3725 (Reference FCR 79420-P)
Specification 13-PM-205, SCN No. 3726 (Reference FCn.79421-P)
Construction has.provided additional anchor strap inspection!
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criteria under WPP/QCI 201.1 and 201.0 via' Procedure Change Notices (PCN) 154 and 105, respectively.
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