IR 05000312/1987003

Ack Receipt of Which Suppls Informing NRC of Steps Taken to Correct Violations in Insp Rept 50-312/87-03.Corrective Actions Will Be Verified During Future Insp

ML20236W995
Person / Time
Site:	Rancho Seco
Issue date:	12/02/1987
From:	Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:	Andognini G SACRAMENTO MUNICIPAL UTILITY DISTRICT
References
NUDOCS 8712080356
Download: ML20236W995 (1)

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, yfl~$?'? g'-[k(   ;sAttention: Nr. G. !Carli Andognini?         '
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t , , fdT' hank 'you!for? your?

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   "' L31987;..: response to our, Notice of Violation!andcInspection' Report:No.. etteriof.. Octoberi20,- 1987.,lwhich!supplementOyour May      1
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'(, l50-312/87-03,4 dated.Ap"ril 16, 1987, in' forming us'.of theisteps.you.have taken.

to correct'the items which.we'. brought to your attention. :Your correctives J

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4 q:.7- 7 Pg 6/" (Your.cooperationhithlusistappreciated. ,

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DESIGNATED ORIGINAIe

:( )   Cert 1"ied'By /And/ N T4h RECEIVED SACRAMENTO MUNICIPAL UTILITY DISTRICT O P. O. Box 15830, Sacramento CA 95852- ,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THERE pF CAllFORNIA GCA 87-633    ;lg81 OCT 21 A Ili l5 j
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OCT 2 01987L

 .U. S. Nuclear Regulatory Commission Attn: J. B'. Martin, Regional Administrator Region V.

Office of Inspection and Enforcement 1450 Maria Lane, Suite.210 Halnut Creek,-CA '94596 00CKET NO. 50-312

 ' RANCHO SECO NUCLEAR GENERATING STATION LICENSE NO. DPR-54.

NRC' INSPECTION 50-312/87-03, ULTRASONIC RESULTS OF.THE PRESSURIZER SUPPORT LUGS

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Dear Mr. Martin:

By letter dated.May.18, 1987, the Sacramento Municipal Utility District responded to a Notice of Violation concerning. welds- not positively identified.

on a system drawing. The District also responded to inspector's comments concerning'the ISI Program, and committed to report findings and any corrective 4 actions identified by the Babcock & Hilcox company review of ultrasonic results of.the-pressurizer support lugs. This Babcock & Hilccm report is attached.

Also, as 'a result of this inspection, the ISI engineer reviewed the UT test report (ISI Figure C2.1.36 for weld 26121-33-BW).- A 60* scan report was part of the package and the required limited scan documentation was completed.

However, to ensure that any other discrepancies in the UT test reports.would not go undetected, the-ISI engineer reviewed all UT test reports for the 1986-outage. This included 36 Class I limited exam test reports and 33 Class 2 limited exam test reports. Of these 69 limited exams performed, three (3) inconsistencies were noted. These inconsistencies were mainly documentation errors. Specifically, the inconsistencies were: a) Failure to identify whether the limited scan was applicable to the 0* or 45* scan. (Fig. C2.1.13) b) Checking that a limited scan was applicable for the 0*, 45', and 60' exam when only a O' and 45* scan was performed. (Fig. C2.1.14) c) Checking no limited scan on the test data sheet but including limited scan documentation for the exam. (Fig. C2.1.85) MMbf)QHQ S$Qo_fVUCLEAR GENERATING STATION C 1444o Twin Cities Road, Herald, CA 95638 9799;(209) 333 2935

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Noneiof the Lincondistencies' are ofik technica1L nature. : Corrections will be-c. m ' smade:in: thel final report:which will: be submitted 90 days .following ' completion' LofLall:. examinations.J Several more examinationssneed to.be performed..the.

[,, 4 v. Lfinall being the RCS Hydrostatic. Test which wil1Lbe performed- during Start-UpF-Please. contact me if.you.have any' questions. Members of your.: staff. with ... questions requiring: additional information or clarification mayl contact Jack J. ' Uhl at:(9.16)'452-3211,1 extension 4376.

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! K Chief Executive Officer, Nuclear.-

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  ' Attachment cc: 'G..Kalman, NRC, Bethesda (2)- (w/atch)

A. D'Angelo NRC, Rancho Seco ( " .) F. J. Miraglia, NRR, Bethesda ( " ) l l

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Nucisar Powsr Division 1

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Babcock & Wilcox - so. cia: Products nd Integrsted Field Servees - a McDermott company . 3110 Odd Fellows Road : Lynchburg, VA 24501 -

      (804) 847 3700 June 12,'1987 M-87-205 Mr. J. H. Uhl Rancho Seco Nuclear Generating Station 14440 Twin Cities Road Herald, CA 95638 Subject:   . Review of Ultrasonic Results of the Pressurizer
   ' Support Lugs Reference:  SMUD Contract 6507 B&W Reference 70.2-0487 1       *

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Dear Mr. Uhl:

This letter'is written in response to your request that B&W l ' review an unresolved item (50-312/87-03-02) identified during a recent NRC audit of the SMUD ultrasonic inspection results for the 1983 and 1985 outages on the pressurizer support lugs. The details of the NRC ob'servations are as follows: Review of ultrasonic inspection results for the pressurizer support lugs (Report Numbers 85-006, 85-007, 85-010, and 85-0014) revealed that additional indications have been detected since the 1983 outage. The inspection results show that some of the new indications are close to previously reported indications suggesting possible . dimensional changes. Fracture mechanics analyses have been I performed by the site Isl contractor and the licensee has filed the reports. However, the reports do not address the following concerns: l 1. Are these indications growing as reported and if they are, what is the rate of growth? 2. If these new indications are fabrication welding indications not detected before, do they require further evaluation to determine why these indications were not detected before? This is an unresolved item pending licensee's action relating to the above concerns and NRC review (50-312/87-03-02).

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MR. J. H. UHL PAGE TWO- i

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       !  t   5 During the.1985 evaluation of the 1985 examination data, the 1983 data was reviewed to access changes from the previous examination. The following table provides.a cross reference for the 1983.and 1985 evaluation reports.

1983 Report 1985 Report LUG AXIS

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83-017 85-006 X-Y 83-029 85-007 Y-Z, 83-032 85-010 W-X 83-018, 85-014

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Y Attachments '1 through 4 review the 1985 evaluations and addresses the NRC concerns as indicated by Questions 1 and 2 above.- Attachment 5 provides information on the measured limits of location and sizing errors for ultrasonic inspections. This attachment is supporting information regarding B&W conclusions i addressed in Attachments 1 through 4.

If you have any questions, please feel free to contact either myself (804) 847-3742, or Mike ac or (804) 847-3788.

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        , 7 ennis M. Turner Contracts & Proposals
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dmc dmt-1710 cc D Mixa JT Janis G Cranston Attachments - Evaluation Report 85-006/83-017 1 Evaluation Report 85-007/83-029 Evaluation Report 85-010/83-032 Evaluation Report 85-014/83-018 Measured Limits of Location and Sizing Errors __ _ , _ _ ___ _ _ - _ _ - - - - . - - - - - - - - - - - - - - - - - - - - ~ - - - - - - - - - - - - - - - ' " ' - - - - "

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g ,; .T. * _ ATTACHMENTS i EVALUATION REPORTS 85-006/83-017 : X-Y AXIS LUG . ( The 1983.~ data reported a ' total of 28 indications on this weld from the 450 and 600 angle beam examinations.

examination a . total of 29' indications . were During reported.

the 1985 In l comparison, the 1983 .and 1985 . data matched - exactly with the , i exception of' indication numbers 207, 417, and 418. l Indication number 207 .was not recorded during the 1983 examination, either because it did not exceed the recording criteria of 50 percent DAC or'it may have been overlooked. The data . recorded for indication number 207 corresponds to .a reflector.(No. 420)' recorded-in 1983 and 1985'and, therefore, it is not considered a new target ' just'more data on an existing.

- reflector. Indication number 207 was recorded with a 450 angle

 . beam and number 420 was recorded with a 600 angle beam. The-recorded DAC.

amplitude for indication number 207 is 80 percent of The length was ' measured at .60 inches and the.throughwall dimension was .50 inches. The recorded dimensions for indication number 420 remained the same for both the 1983 and 1985 examinations.

The.o'ther changes reported in 1985 concerned indication numbers 417 and 418. The table shown below provides a comparison between the 1983 and 1985 data.

. 1983 Data 1985 Data Indication No. 417 Amplitude 63% 80%

   \ Length  .4"   .2" Throughwall  .15"   .15" Indication No. 418 Amplitude  70%. 70%-

Length . 2 5 "- .55"

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Throughwall .25" .25" The magnitude of the changes shown for indications 417 and 418 are within the limits of repeatability that can be reasonably expected using the Section XI examination procedures. The exact reason be that indication number 207 was not recorded in 1983 cannot identified. However, based on the fact none of the other indications changed from 1983 to 1985, it is highly improbable that the changes noted suggest any growth at all. It is more probable that the minor changes in data are attributed to repeatability limitations which are inherent with the ultrasonic > examination process. Since there is no reported growth, the indication growth rate is considered to be zero. For the purposes of the 1985 evaluations, the impact of these reported changes were conservatively evaluated as if they represented changes in the indication sizes.

Report 85-006, a worse-case evaluation As indicated in Evaluation determined that the indications 1983.

were bounded by the fracture analysis performed in l l' l . . . 1:

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 ' EVALUATION REPORTS 85-007/83-029  : Y-Z AXIS LUG'

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1983' data reported a total of eight-indications on;this weld: f rom ' the . 4 50 and 600 = angle beam examinations . - examination, During the.1985

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comparison, a total of.'nine indications were reported. In the 1983 and 1995 data matched exactly with- the.

. exception of indication numbers 202 and 402. 'l-Indication number 202 was' not recorded ~ during the 1983 examination the either because'the amplitude. response did not exceed: i Loverlooked. 50, percent- DAC recording criteria or it may have been The . data recorded f or ' ' indica tion number 202 corresponds to the combined indications 404 .and' 405 which were recorded during ' both the 1983 and 1985 ,'utages o . Indication 202 was recorded with a 450' angle be'am and indications 404 and 405

"  were recorded with a. 600 angle beam. The maximum amplitude recorded
 .65 inches for;andindication 202 is 63of a throughwall percent of DAC with a length. of-
     .35 inches. The recorded'

dimensions for-indications the 1983'and 1985 outages. 404 and 405 remained the same for both i The other change reported involved- indication number 402. A

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comparison of the'1983 and 1985 results is'as follows:  !

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1983 Data 1985 Data Indication No. 402

   \A mplitude 56% 56%

Length .2" .4a

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Throughwall .3" .3"

 'As was the case for Evaluation Reports 85-006/83-017, the magnitude of the changes shown for indication 402 is within the limits of repeatability Section'XI  that can be reasonably expected using the examination procedures. It cannot be determined why indication 202 was not recorded in 1983. 'Each of the items mentioned above are possible explanations. However,  based on the f1985, act. that indications it is unlikely that the 404 and 405 did not change from 1983 to addition of indication 202 represents or indicates . any growth. As previously stated, the minor changes in data are attributed to repeatability limitations    ,

which are inherent with the ultrasonic examination process. { Since there is no reported growth, the indication growth rate is q considered to be zero. For the purposes of the 1985 evaluations ' the impact of these reported changes were conservatively evaluated as if they represented changes in the indication sizes.

. As indicated in Evaluation Report 85-007, a worse-case evaluation determined analysis performed that the indications were bounded by the fracture in 1983.

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ATTACHMENT,3 p EVALUATION' REPORTS 85-010/83-032 : W-X AXIS l L The? 1983 ~ data reported a total of seven indications on this ' weld

from the 4 50.' and . 600 ; angle beam . examinations . During ~ the 1985 examination comparison, a ' total' of eight. indications were reported. In' , the '1983 and 1985 data matched' exactly with the i exception of indications 402, 403,.and 406.

, Indication 406 was not recordad during the 1983 examination-

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either .because' criteria:or it may.haveit did not been exceed the 50 percent DAC recording ~ overlooked.

related to any other indication recorded inThis indication'is 1983 or 1985. not-This-indication had an over the recording threshold.

amplitude measurement of 63 percent DAC, just The length was recorded .at . . 5 inches-and the throughwall was measured at .. 4' inches; Although

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this was- recorded -as a' new . indication .in 1985,. it . probably-

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existed in 19 stated above. ,83 but was not recorded due to one of the reasons a Indications the recorded 402 and 403 did change from 1983 to 1985'according to data. The following table shows a. comparison of.

that data.

1983 Data 1985 Data

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Indication'402 Amplitude ' 70% 100% Length  !

     .4" .9" Throughwall  .4" .7" Indication 403 Amplitude  50%  63%

Length .15" .6" Throughwall 0 .6" As previously stated, the magnitude .of the changes shown for these indications- is considered . to - be .within the limits of repeatability that ~ can be reasonably expected using the Section XI examination procedures.

These indications are in the same general proximity as the rest of the indications (several larger than'402 and 403) which did not show any dimensional changes. If detectable growth were occurring, it is expected that the remaining indications would also have had some change - there was none.

Since there is no reported growth, the idication growth rate is considered to be zero. For the purposes of the 1985 evaluations, the impact of these reported changes were ' conservatively evaluated as if they represented changes in the indication sizes. As indicated in Evaluation r Report 85-010, a

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worse-case evaluation determined that the indications were bounded by the fracture analysis performed in 1983.

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 -EVALUATION REPORTS 85-014/83-018- :  Y' AXIS:

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 :The- 1983Edatai reported a . tot'aliofl '42a indications Jon'1 this i weld?
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Ifrom1 the L450 ~ and; 600 Pangle; beamL examinations . - ,During the 1985; examination . a1. totalt of 43 indications were reported.,s In- ' comparison, the .1983 ': and ' 1985 : data matched L . exactly Ewith the 3

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Indication either ;217 1it because was 1not' : recorded 'during; ;the '19831 examination'

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did.: note- exceed the recordinga thresholdLof L 50 M

 . percent: DAC or.because~it may.have been overlooked. The, maximum;
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amplitude. oft thisLindication'was?63 percent.of DAW with(a; length

 '.4^ inches'and.a-throughwall measurement 'of .25 ! inchesl. There:

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is Jno direct: association? of' this indication 1with ..any; other

 .'recorde'd indication ~

i  ; ' however, it is Lin close' proximity .toL other indications. . Although Vindication: 217 was not recorded '.in' 19 83,. - t it;l probably . exist'ed. ~but? was . not recorded due to 'onel:of; the c

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reasonsEstate,d'above.

- J . Indication number-'409fdid experience a slight change in recorded ' dimensions' : from 1983. to 1985 The following- table provides' a comparison of the' data.

1983 Data'-

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1985 Data LIhdication'No. 409 .. . . Amplitudet ' 63% .63% 1 Lengtht .. .35" .45" Throughwall .30" . 3 0 "' '

/ The' magnitude of Lchange for - this indicationLis considered tol be-within the . limits of = repeatability. that; can . reasonably ,be expected. ;using the Section s . XI examination procedures. Since the're 'is ' no- .. reported. - growth, -the indication growth rate is considered: to.be zero. For the, purposes.of the 1985 evaluation, the impact of these reported changes were. conservatively
* ' evaluated as!if;they represented changes in the indication sizes'.

As indicated in. Evaluation Report 85-014, a worse-case evaluation' determined !that the indications were bounded by the fracture l

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mechanics analysis performed in 1983.

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MEASUREDJLIMITSJOF-LOCATION"AND SIZINGiERRORS'

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  .The variationsLin" data showntin these' evaluations are within the h". '   -limits'ofCrepeatability.iforfASMELSection XI:UT proceduren.- .An';
  ' xcerpt . from a paper" entitled :"The = Evaluation: of: the PISC:' II e

1 Round Robin: tests" presentediat.the'8th. International' Conference-on NDE:in the! Nuclear;IndustryJshows the' magnitude of variations'

'   forldefect" location'and' sizing;thatfwere observed during..,

PISC-II. ' Figure 5 from:this article 7is. presented.: This figure, shows theTdistribution-ofjlocation and; sizing: errors'forJthe

  ' defects in one?ofsthe; plates..

, The. upper.left diagramfindicates the'_ error for' location in theI h ' dimension. .The mean error:is .63" with'a standard. deviation of

   < The! upper right - diagram ' indicates ( the . erroriforflocation i
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1.5"'. . in'the Z dimension. -- The mean error is '.16'.' with a' standard:- deviation of'.62". The lower.left diagram indicates the error;

  .for sizing 11n the-Y directio'n.- The mean error is :.26 with: a
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standard [ deviation of 1.9".- The' lower 1right diagram? indicates the' error;for sizing.in thefZ direction. The mean error'is .'41"' with a, standard deviation of 1.1".

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