ML19289C915

Interim Deficiency Rept on Button Heads Splits of Tendons Used to pre-stress Concrete Containment.Ref 781130 Nonconformance Rept 78-19.Describes Planned Test Program. Final Report Will Be Submitted by 790415

ML19289C915
Person / Time
Site:	Byron
Issue date:	01/05/1979
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML19289C912	List: ML19289C914 ML19289C915
References
NUDOCS 7901260248
Download: ML19289C915 (3)

Text

Commonwealth Ecison U :C Locket. Mos. 5 0 -E.

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. Tills DOCUMENT CONTAINS POOR QUALITY PAGES innON STAT. ton um Tn 1 e." 2 IET MI:* REPORT CONTAINMi?'!T TENDS.' I'71CIEJ.C_'I INRYCO, Inc. submitteS Nonco.n' o':r. n: ~ 1.s port 1:o. 7 L .-

dated Novemb::,: 30, 1978, for Lyron Units 1 and 2. Thic nonec:.f e:nc.nce concerneo a field inspection oi the tendom. cnippad to the L., rer -5+

which do not nect. the IIR.YCO Button Hvad Acceptance Criterin Vd.

The tendons which are the subject of this nonconformance repon cr those used to port-tension the Containment Builc.i:q. for nef r c..

Units 1 and 2. Th poct-tensioning system selected fo.c Eyron U:uts 1 and 2 is a 170 wire EER'? syt ter.t tupplied by IHRYCO, J 'c . 'M poct-tensioning sydc:a tor each Contain nent nuilt'ing in comprueJ o:

120 individen1 do:m tendons, 162 individual verticel te.ndons, end 2(1 individual horir.ontal tendons. Each tendon is cc:cprined of 170, 0.250 inch diamete:. wire conforming to the chemical and physier1 propertie , of AST:. A /.21, G r r.d c E '- steel, having a min 5 7..= u ] . j n E U-tensile strength of 240,000 psi. Metal sh.inthing is embedded ir the Containment Building concrete to serve ac a conduit for the installa-tion of the tendons. A steel anchor head is provided at each end of the tendo , to cerve as a terlaination and anchor point for t.hs tenden wires. Each tendon wire end is upset, forming a buttc,o her ?

to seat the individual wirca on the anchor head. One end of u b wire is button headed in the chop, while the other end is button headed in the field after the tendon hac baen installc6 in the metal sheathing. The tendon: are hydraulically tencioncd af te:- the installatio? of the fielc! nyplicd button heads to approximately 70%

of its ultincte strength.

Field Insoectio:-

IERYCO made field impectionc on Novenbcr 16, 1978 and Novembcr 17, 1978 on the excessible button heads of 46 tendon:

using a fecler gauge and found 13 rejectabic tendonc baccd upon the crack criteria in INRYCO Specification 1610. The rejecticr.s were based upon the existence of splits oriented between 30 and 450, and gru.ter then 0.002" wide; and the cuni total of all split r or the opening in excess of 0.060" of one (1) split oriented at less than 30 0.

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7 NIX 0217

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Commem"enhh Edicon NMC Dochet Ncs. 5 0 /. 5.'

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F 1)iscussion

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Imperfections in both nhop end field applied button headc are to br e.x p _ cten . The acceptable inperfectionn, such es splito and slipc, are defin:.d in the 11 MYCO 130ttcn lead Acccptrnce . n 1610. The Iri,YCG , Jnc. OA/OC procedurc roouires that the shop app.' icd button heads be inspected in accordann with theiv Potten Ec::d Acceptance Criterin 1G10, prior to the chipment of 1.he s tendr, . - -

the job site. This inspection consists of a 100;' visuel inspectier for crac:n, a"6 c ubiuu.. .i C,' cnt :tinc.i i on for butten hacd c i, . ...

a go-no-go g?pge, Shop applied button heads which feil to noct the Dutton Ewd Ace.1 % c7 Criterin 1610 are to be reject <m by II,~2CO

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and cither repaired or replaced prior tn shipment to tht. j cir . t n .

The IN?YCO Nonconformance Report 701-5 has notified Commonwee3tn Edicon Co:ipany that shop rpplicd butica heads were shipp?d to t h .

Byron job nn.c uh!.ch do nct meet the IERYCO Button Head IscceptEnce Criteri? 1610. The primary concern of Cor.raonuccith Ediron compar.:-

is the failure of the IU;YCO, Inc. Quality Accurance procedurce to prcycnt thic occurrenec.

IEWCO, Inc. han contended that the existing Button I' :(

Acceptance Criterir 1610 is conservativc and has ctated that, in their opinion, flaws of the tyca and nother obccrv,'. in the Byron button heado do not impair the structural capacity of tha tendonc to serve their intendnd function. In this rer;?rd, IERYCO, Inc. has proposed to conduci. a test progrnm to substantiate that a more lib ^rcl acceptrnec criteria wil? not jeopardize the adecuccy of the tendons delivered to the Byron job site. The results o2 this test progran and modificd button head acceptance criteria will be nadc available to Ccro." wealth Edison Comp?ny by INRYCO, Inc. on January 31, 19'/ P . In the i ni.eria, INRYCO, Inc. will conduct field inspections of the chop cpplic" button hends at the Byron site usir:g the current acceptance criter n in order to quantify the nnture and extent of the button head defeca,. Thic list \;ill be compared to the revissd button head acceptance criterin, and those button heads which fail to meet the revised button hcLC ceceptance criterin vill be rejectcf.

Commonwealth Edison Company wil3 r.lco conduct an audit of the INRYCO Quality Assurance progre a to acscss IRRYCO, Inc.'s deficienciec.

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,, , Commonwealth Edison NRC Docket Nos. 50-454 50 ',55 I

Thi: test program is c:'.nected to be concludcd erel the

3. , wlLu evaluated by Co=onwealth Edison in the first cruarter of 1979. A final report to co.nplate' the reporting recuircm.'nts of

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10 CFR 50.55(e) will be submitted to Region III by April 15, 1979.

The vendor nonconformance report that documents the 0^~'ciencies o.aserved on Byron Station Units 1 and 2 is on 'ile at the plant site for review (Inland Ryerson Report NC/CA 1;o. 731-9

d. mad 13/30/73). A comolete recort on the wire test prcg:.2c.i'.,ulbr.

and wire inspection results shall be cub.aitted by April 15, 1979 as a part of the final report.

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