IR 05000445/1979015
| ML19276G709 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 06/21/1979 |
| From: | Crossman W, Renee Taylor NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML19276G706 | List: |
| References | |
| 50-445-79-15, 50-446-79-15, NUDOCS 7908270123 | |
| Download: ML19276G709 (9) | |
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U. S. NUCLEAR RECULATORY COSD1ISSION OFFICE OF INSPECTION AND Et:FORCEMENT
REGION IV
Report No. 50-445/79-15; 50-446/79-15 Docket No. 50-445; 50-446 Category A2 Licensee:
Texas Utilities Cenerating Company 2001 Bryri Touer Dallas, Texas 75201 Facility Name:
Comanche Peak, Units 162 Investi ;ation at: Coatanche Peak Steam Electric Station, Glen Rose, Texas
Investigation conducted: May 29 through June 4, 1979 2/!77 Inspectors:
e y R. G. Taylor, Reactor Resident Inspector, Project Sections Date wcw%-
c/zi/7, W. A. Crossman, Chief, Projects Section Date Approved:
hM me G[Z/[77 W. A. Crossman, Chief, Projects Section Date Investip tion Summary:
Invest ia;ation on May 29 throun,h June 4, 1979 (Report No. 50-445/79-15:_50-466/79-15)
Areas Tavestigated:
Special investigation of allegation received regarding improper and potentially very poor welding of inter-plate scans in the Unit 1 Refueling Pool, sperit fuel pools, and transfer canal of the common facility Fuel llandling Building. The investigatic involved twenty-eight inspector-hours by the Reactor Resident Inspector (RRI) and the Chief, Projects Section.
Results:
The allegations were neither specifically confirmed nor refuted.
The allegations, if confirmed, would have no safety significance.
No items of noncompliance or deviations were identified.
790827012_D
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INTRODUCTION Comanche Peak St eata Elect.ric Station (CPSES), Units 1 and 2 are under construction in Somervell Count y, Texas, near the town of Glen Rose, Texas Texas Utilit ies Generating Company in the Construction Permit holder with the constructor and Gibbs and Hill, Inc. as the Brown and Root, Inc. as ArchitecL/ Engineer.
HEASON FOR THC INVl;STIGATION The Region IV Reactor Construction and Engineering Support Branch received a telephone call from a former CPSES employee who reported several allegations indicating a potent.ial breakdown in the CpSES Quality Assurance program and a possible threat to the health and safety of t he public.
The substance of the allegat. ions also appeared in an edition of the Fort Uorth Star-Telegram published on llay 30, 1979.
SUIL'!ARY OF FACTS The Region IV Reactor Construct ion and Engineer ing Support. Branch received a telephone call on May 25, 1979, f rom a party who identi fied himsel f as a former CPSES employee who had worked as a Boilermaker welder.
The call was tahen jointly by the Brant h Chief and the Section Chiefs of the Projects Section and the Engineering Support Section who in '. urn provided the i n fo r-nat ion to the assigned Resident Reactor Inr.pector at CPSES on May 29, 1979.
The allegations were reviewed with the alleger in an interview which took place on May 30, 1979, at his home.
Each of the following allegations relate to welding of stainless steel liners in the Unit 1 Reactor Containment Building or in the common Fuel Handling Building-.
l.
Allegation No. l1/
Welding and weld repairs on the liners were dif ficult because water from concreting activities had run down t he leak chase channels and out. l ast the backing strip into the weld area. Velds finally completed were very poor; some welds had been slugged wi.th weld rod and others were so thin that if buf fed a second time wit.h 120 grit, they would not have passed PT (Penetrant Test).
2.
Allegation No. 2 There are problems with the gate guide (refers to a gate in the Reactor Containment separating the refueling pool from a small storage pool and the transfer canal).
1/The statements above are the allegations as received.
Clarifications obtained fron the alleger during the interview of May 30, 1979, are indicated by parenthesis.
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a.
The gate guide between the large and small pool was welded in the shop.
When the gate guide was installed in the pit, the end bevel was cut off so it could be fit-up.
When the guide was installed, it was not rebeveled and where a fillet weld of 3/8" was required, only 3/16" fillet weld was made.
b.
The gate guide had to be welded to both sides of the liner. When welding the back side, the velder had to crawl down between the rebar t.o get to the weld.
The position was so crowded that the welder could not make a good weld.
Also, the welder couldn't see what. he was welding very well, c.
Six inches of the chase channels were lef t of f the I; ate guide and added after the gate guide was installed.
The rebar was so thick in the areas where welding was performed that "you could hardly get your finger through, much less the welding torch."
Consequently, the welds were not made properly.
3.
Allegation No. 3 Welders have no experience They spend as much as 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br /> trying to make a test weld. They finally learn how to make a weld that will pass the qualifying test and then when they get into the field they don' t know what they're doing.
4.
Allegation No. 4 There is "lets" of QC coverup. QC is " buying-off" on welds over the phone.
One QC inspect.or bought off a seam before he ever saw the seam and it was not a good weld because water was coming through while the weld was being made.
(The buy-of f involved was joint preparation and cleanliness prepar-atory to welding).
5.
Allegation No. 5 Brown and Root is not following procedures in welding the liner plate.
(The procedures referred to are welding procedures and specifically refer to use of a down-hand welding technique being used versus the procedurally required up-band technique).
6.
Allegation No. 6 Some of the top seams 18" above water level on the fuel pool had backing strips tack welded to the liner plate. There are places where the plate did not cover the baching strip.
Ile would not guarantee the weld. The weld was probably 60% rust, air, concrete, etc.
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CONC _LUSIONS Review of the CPSES Final Sa fety Analysir. Report, Project Specifications and Engineering Drawings, as they pertain to the liner fabrication and installation, have led to the following conclusions relative to each allegation st.ated in the Summary of Facts above To bet.ter understand these conclusions, the following considerations are necessary.
The liner systems are not installed to prevent or mitigate the conse-quences of any of the postulated design basis accidents, but ra t he r are installed to prevent an excessive burden on the liquid waste collect. ion and disposal system and to allow the wall and floor area t.o be more easily decontaminated af ter pool usage.
The liners as a functioning element are, therefore, not considered safety related and are not normally included in the NRC inspection program.
The liners, as passive elements and parts of the building structure, are usually classified into seismic Category I since if one or more of the liner plates were to become detached from the wall, serious damage could be done to stored fuel assemblies.
The plates are, therefore, secured to the concrete supporting structure wit h a system of weld studs attached to the back of the plate and embedded into the concrete
'lhe weld stud system is not a iactor in these allegat. ions.
1.
Allegation No. 1 The RRI, based on the interview with the alleger and with other welders, has become reasonably sure that there were difficulties encountered by the welders with water, moisture and in some instances with concrete ou the veld surfaces and that in some instances, the welds may.not. be com-pletely sound internally, These welds, however, serve no strength purpose and need only to be smooth and leak free, factors which are established by visual inspection, dye penetrant examinations, and by vacuum box tests of the joint af ter it is complete.
The allegation, while probably true, ha:. no sa fety consequence.
2.
Allegations No.
2.a_, b &c
These collective allegations, while probably true in a substantial sense, also have no safety consequence. The weld joints in question only need to be smooth and leak f ree in the case of a. and b. and leak free in the
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case of c.
The welds do not. serve to lend strength to the structure.
3.
Allegation No. 3 The project specifications for all welding, including the pool liners, require that welders be qualified 'under the requirements of the American Society of Mechancial Engineers, Boiler and Pressure Vessel Code;Section IX or a comparable requirement such as those of the American Welding 4 --
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Society.
Section IX of the ASMR requires that a welder must perform a weld process involved and the as-welded coupon must pass specified terts when complete. No time limits are specified or implied as a requirewnt in Section IX for making the qualification test coupon weld.
The RRI has verified previously that the site welder qualification pro-gram is in full compliance with Section IX.
4.
Allegation No. 4 The RRI examined the circumstances surrounding the specific portion of the allegation and discussed the matter with the QC inspector directly involved.
It appears that this man, on occasion, was depending on the inspections performed by a fellow inspector and so recorded on the appropriat e weld data card. The joint was covered over with tape af ter it had been inspected for cleanliness and fit-up and the inspector re-leased it over the phone based on the record card entries. Water in the leak chase channels appears to have been a constant problem. The QC inspector nay have made a judgement. error in not re-examining the joint, but not withsta. ding, the joint had been inspected and found satisfactory at that time.
The RRI did not investigate the alleged " lots" of QC coverup because of the lack of specifics.
5.
Allegati_on No.__5 As noted in the Summary of Facts, the general allegation of failing to follow procedures was subsequently refined in the interview wit.h the alleger t.o re!,te specifically to an occasion where the alleger was directed by his supervision to weld down-hand rather than up-hand as required by the velding procedures. ASME Section IX indicates that such a change is in the category of a non-essential variable and, therefore, is out a prohibited change in the procedure, if recorded.
It appears that the change was not recorded.
Interviews with other welders on the sane activity failed to reveal any similar experiences and supervision has denied directing the alleger to perform out-of procedure.
The RRI, there-fore, has no mechanism by which to confirm the allegation.
Again, assuming that the alleger did weld down-hand instead of up-hand for whatever reason, the consequences of such an action are essentially meaningless as related to a weld, since such a change has no effect on the finished weld of the type involved.
6.
Allegation No. 6 The particular welds in question are even less consequential than the other sea n velds in a functional sense These welds, which are above the water line in the pools, do not. need to be leak free, just smooth for the purposes of easy decontamination.
The allegation, while perhaps true, has no conse-quence.
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D2TA[LS 1.
Persons Contacted Allep;r The alleger, hereafter ident illed as Individual "A," is a former employee of Brown and Root, Inc. (the site general contractor).
The person iden-tified himself as a forner welder assigned to the millwright / boilermaker unit of the conutruction force.
Principal Licensee 1:aployee Site Quality Assurance Supervisor Brown and Root, Inc.
Project Construction Manager Millwright / Boilermaker Superintendent Individual "B," a welder currently working as a pipefitter but who was a Boilermaker Individual "C," a welder currently working as a pipefitter but who was a Boilermaker Individual "D," a quality control inspector who was assigned to inspection of poal liners 2.
Background of Allegations Individual "A" contacted the Region IV office at approximately 9:25 a.m.
on Friday, May 25, 1979, to express concerns about the welding activities which har' taken place on the spent fuel pools, cask loading pool and the trans' r canal in the common Fuel Handling Building for both Units as well as that work accomplished in the Unit 1 refue]Ing pool and temporary storage pool installed in the Reactor Containment Building.
'ihe RRL was notified of these allegations on Tuesday, May 29, 1979, (May 28 a holiday) and initiated an immediate investigation.
The first point of contact was the licensee's site Quality Assurance supervisor who informed the RR1 that he was aware of the allegations, since his company had been apprised of them by a newspaper reporter employed by the Fort Worth S t a r-Te legra:n.
The site supervisor also informed the RRI that another welder, Individual
"B," had expressed similar concerns to the Project Construction Manager on May 23, 1979, and that concerns had been forwarded to site Quality Assuranac for investigation.
The RRI was provided an informal memorandum 1, sing the results of the investigation dated May 23, 1979.
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Individual "A" also contacted the Project Construction Manager on May 24, 19/9, and expressed essentially the same coacerns as those expressed by Individual "B" and which in t urn he expressed to the Region IV of fice on May 25, 1979.
It appears that Individual "A" and his supervision, up through t he hoject Cont,truction Manager, had reached a substantial point of disagreement and Individual "A" voluntarily terminated his employment at the site as of May 24, 1979.
The voluntary termination is a matter of record in Individual
"A's" employment file.
3.
Inves t i;;a t i on
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The R"I initiated the site phase of the investigat. ion by extensively reviewing the CPSES Final Safety Analysis Report in order to ascertain the safet.y classification of the various pools and pool liners involved in the allegation and to review the functional descriptions.
Reference to Section 3.2, " Classification of Structures, Components and Systems,"
in the FSAR does not indicate the liners as being safety related although the buildings in which they exist are shown to be in seismic Category I.
Paragraph 3.8.3.7.1 provided a commitment to test the liner seams via a vacuum box for leak Lightness and briefly described a leak chase system behind the liner seams.
Paragraph 3.8.4.1.3 provided a brief additional description of the function of the liners.
Figures 9.3-9 and 11.2-4 revealed that the extensive leak chase system has lead-out piping which leads to a building nump and hence into the liquid radioactive waste collection and dispostil system.
The RR1 t hen obtained Project Specification 2323-SS-18, Revision 3,
"Stainle v. Steel I.iners," to ascertain what requirements the design engineer had established for the liners.
The RR1 noted the following significant it ens from the specification:
a.
The design engineer invoked the general quality assurance requirements of 10 CFR 50, Appendix B on the fabrication and installation work, b.
'Ihe design engineer provided three full pages of detail requirements relative t.o the system of studs to be welded to the reverse or concrete backed side of the liners.
c.
The design engineer made re fe renc e to the inter plate seam welds only by requiring that the welding procedures and welders be qualified to AS'!E,Section IX.
Criteria for finished welds require that., " Surfaces of all welds shall be smooth and free of any irregularities such as serrations, ridges, crevices, or pinholes which may make it subsequently -
dif ficult to achieve an ef fective washdown of the liner surface." Under testing the design engineer provided the following, "All seam welds shall also be tested by vacuum box for leak tightness for their entire lenth."
No other quality requirements were imposed on the seam welds.
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d.
The RH1 then obt.ained the design engineer's drawings S-0831 through S-083'4, SI-0560, t1I-0581, all.of which provide details of liner fabrication and installation.
In addition, the RRI obtained vendor design det. ail drawings for the gate ;;uide installed in the Containment Building between the refueling pool and the temporary storage pool.
These drawings, taken collectively, showed that the design engineer had designed a system wherein the liner plates and the gate guide would be supported by and anchored to the surrounding concret.e walln by a very e> tensive system of "T" headed studs welded to the concrete sides of the plates and gate guide frame.
The seam welds are entirely from plate-to plate and provide no at.tachment into the basic building structure.
The RRI concluded on the basis of the above informat. ion that. the liner syste a had been desigaed such that resistance to seismic ef fect was vested in the "T" headed stud installation and that the seam welds <:ere necessary only to provide a very low leakage path for the pool water and that what leakage might occur would be drained to an appropriately designed method of disposal.
Ihe RRI interviewed Individual "A" on May 30, 1979, in conjunct. ion with the Region IV Reactor Construction and Engineering Branch, Projects Section Chief, in order t.o gain additional informat. ion relative to each of the allegations received over the telephone on May 25, 1979.
The additional information and clarificat. ions were as noted in the Suruaary of Facts included in this report.
In addition, Individual "A" acknowledged that he had only very recent.ly become aware that. the stud system existed for holding the plates in place and was, in fact, unaware that the leak chase channels were piped to a collection point. for controlled collection and disposal of any leakage which might occur.
The RRI interviewed Individual "B" in the presence of the licensee's site QA supervisor, also on flay 30, 1979.
(This arrangment. was allowed since Individual "B" only came to the attention of the RR1 through the assistance of the licensee's representative.) The allegations of Individual "A" were reviewed in detail with Individual "B" who essentially confirmed Allegations 1, 3 and 6, but indicated he had not worked in the Allegation 2 area and f urther. indicated that he had no complaints about lack of ef fective QC nor had he been instructed not to follow welding procedures.
The RR1 interviewed Individual
"C" on May 31, 1979, with the same results as those obtained in the interview with Individual
"B."
Individual "C" indicated that. he perhaps was one of the persons referred t.o by Individual
"A" in Allegation 3.
He also indicated that he had very limited velding experience before coming to work at CPSES and none in "IIeliarc" weld process.
He was giren some forty hours of very informal training and then used fif ty-two hours to make his weld test coupon, a duration that he now considers t.o be excessive.
He now thinks that he is a good welder.
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The RRI intervie.ced Individual
"D" on llay 30, 1979, and again June 1, 1979, to develop any facts relative to the specific allegation of " buying-off" joints over the phone.
Individual "D" categorically denied that he, or to his knowledge any other QC inspector assigned to this work area, had ever
" bought-off" a designated inspection point without making the required inspection.
On Jtute 1,1979, Individual "D" indicated that there had been very few occasions when he had given consent to the tielders to weld up a seam that, by the inspection reports, had been previously inspected for fit-up and cleanliness.
Ife also indicated that he and others had repeatedly stopped work on velding of seams where it came to their attent. ion that water or uoisture uas interfering with good welding.
The RR1 interviewed the Boilermaker Superintendent on June 4,1979, relative to his knowledge and/or participation in any of the allegations.
He cate-gorically denied ever directing welders to r.iake welds where water or moisture was present, but. acknowledged that. it was a constant problem.
He indicated that he finally received engineering permission to drill holes through the liner at the ends of the leak chase charutels so that air could be blown through to dry out the channels and that this action helped a great deal.
He indicated that he had continuely attempted to impress the welders with the importance of making good seam welds.
4.
RRI's Assessment of the Liners The RRI observed some of the welding work on the refueling pool in the Unit No. 1 contaiinaent during the latter part of 1978 and the early part of 1979 incidental to iaaking inspection of other activities in the same work area.
The welding a3 peared to be normal and the dye penetrant examinat. ions appeared to be properly accomplished.
The finished surfaces examined have been uni-formily smooth and appear sound.
The RRI also examined some unfinished areas in the Unit 2 spent fuel pool and can appreciate the difficulties that may be encountered in removing some of the concrete laitance f rom the vertical weld joint areas g_