ML20209J426
| ML20209J426 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/28/1985 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D, Kirsh D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-85, REF-PT21-85-446-000 ANPP-33851-TDS, DER-85-28, PT21-85-446, PT21-85-446-000, NUDOCS 8511140003 | |
| Download: ML20209J426 (5) | |
Text
{{#Wiki_filter:, Arizona Nuclear Power Project P.O. BOX 52034 e PHOENIX, ARIZONA 85072-2034 October 28, 1985 ANPP-33851-TDS/TPS U. S. Nuclear Regulatory Commission Region V 1450 Maria Lane - Suite 210 Walnut Creek, CA 94596-5368 6. ?o 9,1; Attention: Mr. D. F. Kirsch, Acting Director Division of Reactor Safety and Projects 9
Subject:
Final Report - DER 85-28 fo N A 50.55(e) Reportable Condition Relating to CE Instrument Rack Conduit Installations File: 85-019-026; D.4.33.2
Reference:
A) Telephone Conversation between R. C. Sorensen and T. Siegfried, August 21, 1985. B) ANPP-33573, dated September 18, 1985 (Interim Report) C) ANPP-33679, dated October 8, 1985 (Time Extension)
Dear Sir:
Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e), referenced above. The 10CFR21 evaluation is also included in this report. Very truly yours, afa&& 4 9 E. E. Van Brunt, Jr. Executive Vice President Project Dinctor EEVB/TPS/ldf Attachment cc: See Page Two h S ' l $D
7 .m {t ; 3-t k ANPP-33851-TDS/TPS October'28,:1985 ~ Mr.~ D. F.-Kirsch DER 85-28 Page.Two cc: Richard DeYoung Director:- Office of Inspection and Enforcement' U. S. Nuclear Regulatory Commission Washington, D. C. 20555 'J. G. Haynes D.' B.;Karner W. E. Ide D.'B.-Fasnacht A.'C. Rogers L. A. Souza-T. D. Shriver-D. E. Fowler ~ C. N. Russo J.. J. R. Bynum J. M. Allen D. Canady A. C. Gehr G. A. Hierzer .W. G.. Bingham R. L. Patterson R. W. Welcher H. D. Foster D. R. Zimmerman M. L.' Clyde D. R..Hawkinson B. T. Parker-J. Provosoli 'D.-N. Stover-J.ED. Houchen TJ. E..Kirby. .RecordsiCenter Institute-of Nuclear PowerL0perations 1100 Circle 75 Parkway,nSuite 1500 .-Atlanta,-Georgia 30339 e I [.- -{ k. i - -f Q. ~
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- FINAL REPORT.~ DER'85-28 i e + DEFICIENCY EVALUATION 50.55.(e): 4 x ? ARIZONA. NUCLEAR POWER PROJECT.(ANPP)~ n. o t inc e _ PVNGS UNITS:1, 2, 3
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.I. -Description of Deficiency-Combustion. Engineering l(C-E) Letter V-CE-32386. identified three (3) ~ Problems with Unit 2 Service-Air flexible stainless: steel conduit installations on the C-E.su'pplied: instrument racks..The flex' conduits were supplied and --installed by C--E. + A. -Approximately 50 percentiof. roughly,two;.hundrediforty_(240) conduits- .do not meet minimum conduit bend radius'apecification of-1.67" at, centerline of:the: conduit.. ? - .Bi Seventeen (17)l flex conduits have'been damaged to'the extent that the inner conduit tubing was broken.. C. Additionally, some 20-30. percent of.the-nuts on'.theiconduit fit _ tings-were found to be loose. LThreeJof the conduits'were found;to-be-completely disconnected from the~' fittings.- c EVALUATION 'E ' The three conditions identified'in Unit 2 are evaluated as follows: ya c + d ' ~i k i,- .E
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A. Minimum Bend Radius. J g5 an. m py Per,the.C-E letter referenc'ed.above, C-E inspecte'dTall< Unit 21
- instrument rack' flex conduits and-concidded that the-as-built-
- flexible conduit' installations that?have' not bee'n!dddaged 'are;Q f ' acceptable'even though they violate'the' minimum' bend radiu's ~ specification.' These; installations; are acceptable to. C-E. ;because - .i s ~ , ; of. the highly ~ redundant method.of clamNng' thatjis [ employed. ? The ' ^ n redundant:diamping restriEts theTaovement ofithe cdaduit which: 7 prevents > additional'~ stress =on the conduit. ; Additionally,' stainless -s ! steel. conduit is;not subject tola'ging.1 The'refore,Jthe as-built t l ) t conduit, bend: radius,willjnot further affect 1the integrity of the' (undamaged flex conduit., , g 'l, o j. 2 x ', f ~?C-E;is satisfied th'attthefcableslinDthe nondamaged flex conduits'have , (
- not;.been degraded by the as-inst'alled' conduit' bend radius. Thef Y
recommende'd: permanent?: set bendtradii:of the; cables lare lessithan the- .maximn= bend radius;ofithe"flextconduit!-.Duelto theicompositioniof
- 4 these? cable's :they,will5 tend (to:foll'ow the1 outer. bend,of the flex ~
l conduit.D Additionally, in seismic; tests on instrumantiracks j 1
- conducted by
- C-EC the flex conduits were installed Mith similar-
-f e ~ j y g $ bending radii and no malfunction due.(to(cableEdamageiwasiobserved.: Nf Seismic 1tesi wasfdocumented oniBechteliLog No.i N001-13.01-868.- ,y ,a m ~' + ,m w .a> e 7.; u % ~ v -y 7 2 y V - ? :~ 4 ,py s + 7 y
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[PageTwo; ,n ru 1 t l The root cause.of this con'dition is the equipment layout of the instrument racks, which C-E attributes.co an isolated case of design e
- oversight._
~ e- _B. Damaged CoEduit ~ f: 3 ;- [Thedamagedflex'conduitscontainsafetyrelated_instrumentcircuits. iTh'. sharp edgelof the broken inner tubing-could possibly cut these ~ e cables during'a safe shutdown' earth'qu'ake and render these circuits inoperable.. These in'strument' circuits;are designed with two out of 'i four;1ogic.fso loss of one channel is not immediately critical to i operatlon._ ^If more than one channel is lost during normal plant 7 ? operation,' the ssnsor. failure signal 'will. trip 'the reactor which is a fail safe condition'. ;However, failure of several' instruments during 7 0 plant' emergency could have resulted' in; the loss of critical post
- accident monitoring instrumentation, which could compromise plant m
' recovery action. 1-: -For ten (10) of the damaged-conduits, the root cause is the frequent reconnection of the flex conduit. This condition was further degraded ~ by other: construction and startup activities on and around the racks since the instrument racks are located near high-traffic areas. The remaining seven (7) broken conduits are located'on(the right side 'of the RCP Speed Sensor ~ Junction' Box. The rocticause of this condition ,+ results from the high stress on the flex conduit due to the equipment ~ configuration on the instrument racks'. ~C. Loose and Disconnected Conduit Fit! tings L. i ~ ':During startup activitiec~, instrument _s may bejremoved for calibration / ' change-out/ relocation, and as'a. result,the conduit-connections ~to.the ' instruments;are not'always properly tightened upon replacement. The _ reason'~ for"this,is that they:are still in an interim mode' subject to i 4 "further removal for additional' adjustments and tests.u The Unit 2 instrument' racks where_this conditioniwas:found are:still under'the.^ M ys istartup organization. :At the completion of this interim mode,ithe - r"' c % : equipment;is-ret'urned toLits origitialiconfigurationJwhich includes ~ y Lproper tightening of conduit fitting nuts. F _ y:. , t ~ (,
- D. ! Unit 3 Inspection.
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- ' 1 (The'2 flex
- conduit installations on the instrumentiracks'in Unit 3;were 4
$((k" ~ -(also'investigat'ed.by.Becht'elEngineering.1iApproximately80 percent.of .the flex conduits haveinot been' completely 7 installed.j NCR EC-6155-4 elisted'the' installed conduits which. violated =the minimum bend radius 1 -m 9: a < specification.1No, damaged. conduits were-iden'tified. : <The NCR was : - ,g W
- disposition USE-AS-IS based on the 'same.; evaluation as - given -in'I.M A E fE; above'. '
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~ FINAL REPORT - DER 85-28 II. Analysis of Safety Implications This evaluation has concluded that the consequence of this condition is such that one or more independent instrument channels could be affected by a common event, this condition, if left uncorrected, would represent a safety significant condition. Therefore, this condition is evaluated as reportable under the requirements of 10CFR50.55(e) and 10CFR Part 21. III.- Corrective Action Unit 1 Anaconda flex conduit was installed by Bechtel instead of the Service Air flex conduit in order to meet test schedule. Damage to the Service Air flex conduit is not very noticeable since the conduit is covered with a stainless steel braid. The Anaconda flex conduit does not have this braid and any damage will be obvious and unlikely to remain undetected during startup and operations testing. No_ damaged cable or conduit was identified during operations testing and area turn over walkdown. Therefore, this problem does not apply to Unit 1. Unit 2 The Unit 2 instrument rack conduit installation will be-inspected and reworked under NCR SJ-5279. The sevenceen (17) damaged flex conduits will be replaced. A 90 degree elbow fitting will be installed at the high stress point of the RCP Speed Sensor Junction Box.i, C-E will supply the material with detail installation instructions for.the conduit repairs and elbow installation for this C-E design change. All Unit 2 C-E instrument rack conduit, fitting' nuts will be. inspected and retorqued as necessary. Work is scheduled to-be c'ompleted by_0ctober 30, 1985. Unit 3 Interoffice Memorandum E-1'2793 informed construction o'f this condition ~ for the-completion of the remaining instrument rack flex conduit installation. Upon construction completfoa, a special-CIP will inspect the Unit 3 C-E instrument racks for damaged conduits and loose fitting -nuts. - Any damages and rework will-be documented by NCR's. DCP 30E-SB-054 will install a 90 degree elbov fitting at the RCP speed Sensor Junction Box. _.}}