ML20214G429

Forwards Info Re Fabrication Difficulties Experienced in Attachment of Main Steam Relief Valve Platform Support Ring to Containment Vessel.Lamellar Tearing Detected During Insp. Review of Design & Fabrication Underway

ML20214G429
Person / Time
Site:	Columbia
Issue date:	03/07/1975
From:	Stein J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
CON-WNP-0043, CON-WNP-43 GO2-75-72, NUDOCS 8605220106
Download: ML20214G429 (7)

Text

{{#Wiki_filter:.. )<: 'a) '"3 Washir on Public Power Supply Syst h g 8.i A JO;;U OTUAllNG AGU.cY r... ! qa cd P. o. son 96e sooo oro wasan.oron war R.'catano. waswie.sta=,,3,a PMoest (509) 946 950 8 March 7, 1975 G02-75-72 W n, ? 9 ' Mk.:0 ' MQ Mr. R. H. Engelken, Director - Qe ^.

• hv -

Nuclear Regulatory Commission Region V tq M, q, ~ 1990 North California Blvd. ' c. d. l,.G ( @ " f,i.S C h Walnut Creek Plaza, Suite 202 g >/ Walnut Creek, California 94596

Subject:

WPPSS NUCLEAR PROJECT NO. 2 (DOCKET 50-397) N' _ FABRICATION DIFFICULTIES, STEEL CONTAINMENT VESSEL

Dear Mr. Engelken:

The purpose of this letter is to advance information to you regarding the nature of the fabrication difficulties being experienced in the attachment of the main steam relief valve platform succort ring to the WNP-2 steel containment vessel under construction by Pittsburg-Ues Moines (PDM). It is our position that these fabrication problems are not classed as a deficiency reportable under the provisions of paragraph 50.55(e) of 10 CFR 50. The following summary of findings and progress in the examination of this problem are presented for your review:

1) The basic problem is the presence of what appears to be "lamellar tears" in containment vessel plate adjacent to the weld attaching the large " box-girder" which is the support ring.

(Theconfiguration is provided as Attachment I to this letter).

2) These tears were detected in the course of routine inspection, recorded and reported to the appropriate Engineering and Quality Assurance organizations for disposition in accordance with the procedures of the PDM, Burns & Roe and WPPSS Quality Assurance Programs.

.p.... : s 3T'Me "eitent"of 'these'"t' ars"'can be'summaiized as 'follows: " ' ' : % + : % 6-'

• e

e. : ~,:

. c,.c .a) Two. tears on the top, 8'-7" and 7'-4" long, and one 2'.long.on ithe bottom were detected visually in preparation for routine magnetic partic. le t.,esting. t.v.. t, .,,s .. r &.. y... .:..:.:... ;,.. ;......... +.,n:,.. .n... ;,,;..~ c .v.,..... ..... +.

s. 7 7,

.c.., ;..;.,,,,.,

.i .e ..g,, 1 8605220106 750307 ~ PDR ADOCK 00000397 PDR

Kr.'. R. H. Engelken Nuclear Regulatory Comr. sion bch 7,1975 Page 2 002-75-72 c

3) continued:

b) There was one 6" indication on the top and approximately 21 other indications opposite the bottom weld which were detected in the course of 100% ultrasonic testing of remaining weld zones on top and bottom. These indications range from 1/4" to 40" in length.

4) We have directed Burns & Roe, the drchitect-Engineer and Construction Manager, to do whatever is required to resolve this problem as expeditiously as possible. The actions to date consist of:

a) An evaluation of the characteristics of a sample of metal from the tear area by Anamet Laboratories Inc., and the U.S. Steel Research Laboratory (see Attachment 2) which have established the conformance of the material to the specification; no defects in the material adjacent to the fracture, and a conclusion by the PDM Chief Welding Engineer that a "lamellar tear of a restrained joint" had occurred. Working with this as a preliminary diagnosis, an evaluation of the evidence by the Burns and Roe metallurgist resulted in a concurrence with this opinion. . b) A separate evaluation of fabrication techniques and any signifi- ~ cant fabrication stresses is being conducted by PnN and Burns & Roe. This evaluation has not yet been finalized, c) PDM has prepared a repair procedure in accordance with the require-ments of Section III of the ASME Code and obtained the approval of the Authorized Inspector (Factory Mutual Engineering), Burns & Roe and plans to proceed with defect removal of the first of the tears. To further summarize Burns & Roc and PDM findings at the present, this appears to be related to the combination of the heavy section of the material and the geometry involved. This problem was considered in the design of the weld geometry by PDM, and further review of design and fabrication technique is underway to establish the cause of the tears and determine repairs and/or modifications required to complete an approved containment vessel. We will keep you informed of further developments. [ .. c,y :,... u.3. ;.... ;.o - .e.n: s-3:.Ru. W yfpy.truly yours, ' " D '# , v.. ~ - 5 T.. , SW v ~ -' 'y:: .s 'c .p... :,, .e..'. '.J. ' - J ' STEIN s naging Director ..... c. r-v. ;..c..v.: '. +

• ... ~ -.

.~. *. - - . :~ '. ~- i JJS: MEW: cab .: :. m. Attachments ..:..,,.......,....,.:,,q...,;;:....,..,.. l e.-: ...- :. a.. ...o..:; -.i.:.n.. :..

...: r.

..<.v .+....

r

.: c 4 -emor e

e t I g .y . s .a - ([*,, ',. CONTAINMENT VESSEL SHELL V '?

- 2.

MATERIAL A 537 s 1 s y. t z. j e. LAMMELAR TEAR AREA ~ 'd .) )_ l N' .. ',y. (APPR0X.)./[,, / y j -J PIPE WHIP SUPPORT' e. r fg,,, c.. f.. (TYPICAL) f. .s. ..p. ~ s s s .. ~... s g Ygg~' -M".k-8 ~; 7,. 4. j' 'j ATTACHMENT 1 - SKETCH OF VESSEL-SUPPORT UECMETRY g. e s. '4- ' ~ 3 =

... PlV.YC CU AGH-DEC M OIN EG STO L C OM PA N Y f/, f )

l...

......r. January 2S, 1975. United States Stcc1 CoPporation GOD Grant Street - / C j'~ ~ e n ;~ lic o.'s C:11 g[ g C, b 1__ i 2-P i t t s b u r t.: h, Pa. 15200 Attention: ?.f r. Hon Norris J A?. 3 C,. - 7'

Subject:

Contract 127G4 Weld Craking on Toa of Fillet RIC,o m.,.p;) - - y n-- saado to Face of 1}" Plate

Dear ?.!r. Norris:

Reference is made to oua-telephone conversation of January 27, 1975 requesting assistance from United States Steel Corporation in interprcting what may have caused several cracks in making a girder connec-tion to the shell plate of the above contract. We are asking for your evaluation in this matter as a follove-up reques t to us by Burns and Roc's mor-allurgist, the engineers on this contract. I r.:entioned to you' that T had discussed this probicm with Dr. O. Doty at your laboratory and he felt that if he had United Statcs Stoc1's sales approval, he would proceed to evalu:ite the probleu. You agreed and under separate cover, we are sending Dt. Doty a drawin'; showing the vessel and girder design and a chip of metal . removed from the cracked area. The chipped piece was removed from the area noted in shotch below: ~7 c41F OF m E rat. Ps E tao VE D /Q.%r'- V 4 }V. swg O ^y (\\,.rf ,3., n., l s y ... i s.,;.. 4 N ..s o.a ca ux , p..... " g...

s. e.s..

y s. q.... . ( N g 'Q' A 53 (.., e.,c;:.: y ..,..,(, .x x. s s ,s s .. q, 4.,......, 4 . ( s, .s... . t:..- ... s.. Qpx ' ~~M \\ DcrAit C Dw n. E 62 t. 1

i l 1 l i C. :. - 1 2-1 ,= ' United States Steel Corporation January 28, 19"5 The chipped out piece has.some tool mai hs used in re-anoving the section and the balance in dark in colot. ....We believe the dark color is caused by ARCAllt houging heat. The Burns and 1100 metall'urgist sho. fed concern about the fracture and would like to kno.r whether it is a brittle or ductil'e f2acture. We believe this is a well recognized phenomem and will discuss it further after Dr. Doty's evaluation. By copy of this letter Dr. Doty will be notified to sub:ait any written report to United States Stoc1 Corporation Technical Service prior to issue. The material used in the structure was supplied by United States Steel. '. '-4" Area '14" Shell IIT V73051 Slab 03W2 1[" Webs Irr 7/ D35G Slab 237G4S

I.

8' Aren '14" Shell 11T W730bl Slab 05W2 1}" Webs IIT 71065G Slab 237G-18 An early written reply will be appreciated since Burns ~ and Roe Enginecrs arc delaying approval of our repair . procedure until they receive United States Steel Corporation's opinion. Sincerely, PITTSBURGII-DES h!OINES STEEL CO'.!PANY I ) f/ pye..i.y 11 V LC:mfb ' Larry Colarossi, Chief Welding Engineer. ?.:'r. g.-l.!'+....:s:n.;.,(.;,

.4;. g.,v_,,..j.

". e P .c. ., t.....;..,,.,.,,.,.

..q.- -.. _... '. -l 2, '

e,.

AUANhT 3 ', ' ' _REdORDOFEVENTS .c

1) Friday, January 3, 1975.

a) Crack originally discovered by PDM personnel during visual inspection of the pipe whip support to containment vessel shell weld, prior to preparations for performing MT inspection of the pipe whip support weld.

2) Friday, January 3, 1975.

a) PDM QA - Les Sutton, put hold tags, Numbers 00287 and 00288, on the vessel shell adjacent to the crack area. b) PDM Project Manager - Max Schulze, contacted Nick DeStefano - PDM Western Division Welding Engineer, Santa Clara, for assistance in evaluating cracking problem.

3) Saturday, January 4, 1975, a) Nick DeStefano arrived on site from Santa Clara.

b) Removed a specimen from the cracked area for chemical analysis. The ' specimen included a section of the containment vessel base material and pipe whip support weld. c) Crack area specimen sent to: Anamet Lab, Berkely, Calif., for analysis by Nick DeStefano. (For results of specimen analysis see Anamet Lab Report, Letter dated January 17, 1975, Anamet Lab No. 175.102, P.O. 9364)

4) Monday, January 6,1975 a) Burns & Roe QA - MG Krisher, was advised by LR Sutton - PDM QA, of

, existence of pipe whip support crack, and that PDM was proceeding with repair using routine repair procedure. b) PDM QA Site performed preliminary UT Scan of crack area using Site NDT technician, c) PDM QA - LR Sutton requested assistance of NDT-UT Technician from corporate QA (Provo Shop) to UT entire crack area.

5) Tuesday, January 7, 1975 a) Burns & Roe QA - MG Krisher, advised by PDM QA - LR Sutton, that the scheduled repair was not a " routine" repair, and repairs would be stopped pending further evaluation of the crack areas.

6) Wednesday, January 8,1975.

a) PDM, NDT-UT Level I Technician, M. Cameron, arrived from Provo Shop. Proceeded with UT inspection of crack area. (See PDM Deviation or Variation Report (DVR) on results of UT inspection. Dated January 13, 1975. (B&RFileNo.E52-0802)

Sheet 2 of 2 .e 3

7) Friday, January 10, 1975 a) UT inspection by Provo Shop UT Technician completed.

(See item 6 for Report No.)

8) Monday, January 13, 1975 a) PDM QA - LR Sutton, prepared NCR on pipe whip support crack.

Transmitted same to Burns & Roe Site QA on 1/15/75.

9) Saturday, January 18, 1975 l

a) Visual inspection of the pipe' whip support crack areas was performed l by H. Lunt, Burns & Roe N.Y. (see conference notes No. 316, dated 1/18/75) and L.J. Rousseau, WPPSS. (See IOM, No. QA-2-75-21, dated 1/23/75). b) H. Lunt, Burns & Roe N.Y., requested that PDM remove another specimen for fracture analysis.

10) Monday, January 20, 1975 a) PDM removed the requested specimen per H. Lunt's request. Specimen was shipped to PDM's corporate Metallurgy Department, Pittsburgh.

A section of the specimen was sent by PDM Metallurgy Dept. to US Steel (Manufacturers of the base material) for their evaluation. (Seeletter, US Steel to PDM, dated February 3,1975, for their analysis of fracture).

11) Period January 21 through Febr,uary 21', 1975 a) Exchange and evaluation of correspondence, test reports, and preparation of repair procedure dated 1/29/75.

12) ' Monday, February 24, 1975 Burns & Roe notified by PDM QA, letter addendum to NRC 213-0058 of third crack approximately two (2) feet long, located in bottom plate of subject pipe whip support. Nature of the cracked area is the same as des ribed for the top plate of this pipe whip support.

13) Saturday, March 1, Sunday, March 2 a) Further Ultrasonic Testing by Hamill Manufacturing Company (Report No. 001) resulting in complete map of significant indications on both top and bottom of girder.

" M 9 eree -e >=e.

~ APR 9 1975 H.1). Thornburg, Chief, Field Support & Enforcement Branch IE WASHINGTON PUBLIC POWER SUPPLY SYSTEM - WNP-2 (DOCKET NO. 50-397); WELDMENT DIFFICULTIES INVOLVING STEEL CONTAIMENT VESSEL (AITS H00664H1) This refers to your request concerning the reported lamellar decohesion cracking experience with the relief valve support ring attachment to the containment vessel at the subject facility. We have discussed the problem with General Electric and were advised that their engineering staff is working with Burns & Roe (A-E) on possible modifications ef the weldment to minimize effects of welding and restraint parameters on the bases metal (transverse thickness stresses) which are believed to have promoted the conditions observed. Regarding the generic aspects, GE infonned us that no similar experience with the advanced GE contairunent design elsarbere has been reported and attribute this to differences in other A-E designed component support structures. Accordingly, we believe that aside from follow-on review of the failure mode analysis, related weldment modifications, repair and QA measures by WPPSS, no futher action is warranted at this time. It may be noted that decohesion cracking (lamellar tearing) of under-weld base material in weld operations is a well recognized anamoly, particularly among carbon steels due to their variant anistropic prop-erties and plate quality. Because of this, the ASME Subgroup on Fabrication and Examination has proposed revisions to Subsection NF and Appendix XVII of ASME Code Section III relative to this matter. These changes are discussed in Enclosure (1). This infonnation is submitted to provide functional guidance only in Region V development of their review and evaluation of the licensee's proposed repair program within the context of applicable code rules. It should be emphasized that the renedial welding modifications stated are not mutually exclusive and that QA/QC measures relating to electrode control, welding operations and post-weld NDE (MT supplemented by UT) are essential to reasonably assure weldment integrity. OriginalsignedW ' E.V. Scyf rit Karl V. Seyfrit. Chief Technical Assistance Branch, IE

Enclosure:

7" Loddings In the Short Transverse Direction C&O:62/H00664H1 G7S.Sponcer, IE:V (w , }O,,. TA Q IE: TAB 4 / enclosure).. WJCo ins:sgt KVSeyfrit 4/g/75 4/<j/75 Form AEC-318 (Rev 9-53) AECM 0240

1. u. s. oovan=m ant eni= vino orreces ser..sa.-i.e Ob ja uv /

\\

s Enciosure (1) Agenda Item F6E-74-35 N-73-4 ^ LOADINGS IN THE SHO'RT TRANSVERSE DIRECTION Proposed Revision of Subsection NF and Appendix XVII 1. Delete the following: d NF-3226.5 c,# / ',' f NF-3321,1(c) NF-3391.1(b) M ', e ' NF-3392.1(b) I q'(I ' .,. U... Fig. NF-3226.5-1 k E .,s 3 p qq ..h ? ? "', Fig. NF-3321.l(c)-1 te s' XVII-2211(c) fe 'gr Fig. XVII-2211(c)-1 Jo' a .W, b, r. c V 2. Add a new NF-3294 as follows: h k, NF-3294 SPECIAL WELD JOINT LIMITATIONS j [Y direction of material over 5/8 inch thick shall meet the requirements A Weld joints which transmit tension stresses in the through thickness T \\{'t f of (a)3 (h), C (c) bele',.. 1 g,A

• (a) The veld joint shall be designed to minimize through thickness

, f.* 'l stresses caused by weld solidification during f abrication. The t p weld contact surf ace shall not be perpendi*cular to the through f e c thickness direction (Fig. 3294(a)-1). The weld shall develop the I Y' required strength with a minimum volume of weld metal. 't .\\ 4 pc s..., e ry.... a. h ~*D '.' %....~ ; I.... * - W - & 'Ihis [ ' o f (b) The material shall have through thickness properties meeting the f,e' * * ',r, , materials specification mechanical, properties requirements. r O g.'. t requirement may be met by eitheffdata for the heat of material or Z kp?j'/* sufficient data to indicate that the type of steel and steelmakin y practice consistently provide material meeting the requirement. e u t j' [(c) The weld joint shall be designed and fabricated in accordance with p,- NF-4430. 3. Add a new XVII-2455 as follows: XVII-2455 SPECIAL WELD JOINT LIMITATIONS Weld joints which transmit tension stresses in the through thickness direction of material over 5/8 inch thick shall meet the requirements of (a), (b), or, (c) below. /) m A s.,/ 3 9te.l ~. .a s<: yn.- a s '. $k, r *

• a s,.

wks.< ~#.s % " ~*** '** ' ' 7 f~t'")::.,..> th s.k o.s c,4.n. e.<e 35tc s t c % (.Cs ^ a r 4 v.- J A w a,~ r. . ~ m... y _"

• A*.b l] rv.:

,g a, o..., e ~ ~'. : s d,n3../c s %. /Y E/r 'd.5 s l"

(a) The weld joint shall be designed to ninimize through thickness stresses caused by weld solidification during fabrication. The weld contact surface shall not be perpendicular to the through thickness direction (Fig. XVII-2455(a)-1). The weld shall develop the required strength with a minimum volume of weld metal. (b) The material shall have through thickness properties meeting the materials specifiction mechanical properties requirements. This requirement may be met by either data for the heat of material or h sufficient data to indicate that the type of steel and steelmaking practice consistently provide naterial meeting the requirement. (c) The veld joint shall be designed and fabricated in accordance with NF-4430. 4. Add a new paragraph NF-4430: NF-4430 Special Weld Joints NF-4431 The requirements of NF-4430 apply only to welded joints which transmit tensile stresses in the through thickness direction and do not meet the requirements of hT-3294(a) or (b) or XVII-2455(a) or (b). Filler Metal (v. r%,r l (X'+/~ '. c. 4 /,1 enfar,, / ~ %ce t..}/ NF-4432 e A,, & % 4, % ye m :/ r4 f.,' re ae.i,g., oh a,., g ~ cm ba Fr: ~. c ~ r y r Fillcr cctal shall be selected tu match, as closely as possible, the tensile strength of the materials being joined. When two materials of different strength level are joined,. the filler metal shall be selt.cted to match the lower tensile strength base material. Care shauld be exercised du' ring fabrication to prevent over welding. NF-4433 Preheat -{Bh t* M /c; farwr.1 s A.>ru n w'l.SA. '- 4: 4 ~1.k'tc.l '

• Mx k.m t ?

.~'r e:r y c a p o src,,) A Preheating, except for electroslag or electrogas welding processes, shall be in accordance with Appendix D and shall be mandatory. hT-4434 Buttering Techniques Weld metal shall be deposited on plate surfaces at the point of attachment and shall extend the width of the completed weld plus 1/2 inch minimum on either side and full length plus 1/2 inch on Y either end. Buttering may be deposited in a groove cut into the plate or may be deposited on the plate surface. The depth of the buttering shall be shown by demonstration, for each velding process i \\ used, to extend 1/4 inch beyond the depth of fusion of the initial weld passes for joint welding. This requirement shall not apply I to electroslag or electregas welding processes. (Figure 4434-1) NF-4435 Welding Sequence i Double welded " tee" joints shall be welded by alternate passes or layers on each side of the joint in order to balance weld \\/ shrinkage stresses on both sides of the weld joint. l

a l I ~/! >\\ 'l 'l/ 1 ~ i l i i I 4 ~! /j-9 U&t9'^ u^=~.orne,L E e .....3 _g LIN I ~ I i Lp 4l. 8 I 0 CC.if7ASL E ( I l l f/G. 32?'Y[ ~l .'j.ss.as T/r>T/>rJ5 o f ~3b is> 1* S s. f*o/: 7t'r' /13 til TTI tXr R+R o Ja-ii Tiis CxiL S & ~f~:.*tJS/ 'd S7*/l *SSE G l l 1 l i I l

s l (- g ) ).. i I kE

>\\-

- '\\- UtJ/)cc97,93,, g-e h. ~. ( / t t A[ s. t Lg O CCif1~r16LE 5/G.E'l55(ch'l ' - / u. 0 S *T7!r'kT/.> rJS o t~ 3*?>ts.'7~S . s. /~oA 7 f.ilIS hlT TIN 3r TMA'J J.: :: ~~~n,C. O L S S ~7~itJSIM S 7tlL*SSE S O ~ ~ ~ * * - '~ h a c n-

p L 4 v,$ 4J.

x............,...,... -

,... a. .2.r.......x. ..1 S,,ne L L.1 p' N. : ' ./: / y;\\ i ITYP M i .'oJ /6) .d i s -[..j Pl/orz s.: u,. ....,:... w - m .r..-.=. . a.= m .- m ~ v. ~ i.c.:.prr-aerc + /:- a. ~ +.=....,_m?.;g.=. ,.2 / e.. / ,4 II/ L c A ML-8orizann ci a sc a s s.au,) t (C') /Al (a)ot qh.) /)t3sv,., s. ?!&. VY3Y Exnn Ptti5 oF 0> 07 TE f.?IJG T/ Ci!!)! D' '." C

w... UNITED STATES UCLEAR REGULATORY COMMISSION i hEGeoN V $UITE 202. W ALNUT C REEK PLAZ A 1990 N. CALIFOANf A 80VLEVAPO W ALNUT CRF E A. C ALIFOR NI A 94l96 MAR i s 1975 H. D. Thornburg, Chief, Field Support & Enforceme'nt Office of Inspection & Enforceraent, HQ WASHINGTON PUBLIC POWER SUPPLY SYSTEM, WNP-2 (FORMERLY HANFORD 2) DOCKET No. 50-397, FABRICATION PROBLEM WITH CONTAINMENT VESSEL Attached for information and any consnents is a preliminary report by the licensee on a fabrication problem with the WNP-2 contain-ment liner. Although information is preliminary, IE:V believes the problem might be applicable to other containment structures of similar design. There are ten other reactors with over-under pressure suppression containment but WNP-2 is the only one of these ten plants utilizing Burns & Roe as A-E. It is also possible that the problem originated from improper welding procedures or is metallurgical in nature. ?? 11:r.::: ;= ;ier.04 t:w.opvai..' iliLy of ents item under u 50.55(e) which is the IE:V position. However, the licensee had no problem with supplying a report in response to a specific request by W. G. Albert, the principal inspector. We will keep you advised as further information becomes available. Our next inspection at this facility is scheduled for aid April. mc / G. S. Spencer, Chief Reactor Testing and Operations Br.

Attachment:

Copy ltr, J. J. Stein to Engelken, dtd 3/7/75, w/attchments h A G 2 /

1. 1. / 19D 6

46 --}}