ML18064A576
| ML18064A576 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 01/16/1995 |
| From: | Fenech R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M83227, NUDOCS 9501240400 | |
| Download: ML18064A576 (26) | |
Text
tJ consumers Power POWERIN&
MICHlliAN"'S PROliRESS Site Offices: 27780 Blue Star Memorial Highway, Covert Ml 49043 * (616) 764-8913, Ext 0210 January 16, 1995 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT Robert A Fenech Vice President Nuclear Operations RESPONSE TO THE JANUARY 9, 1995 NRC REQUEST FOR ADDITIONAL INFORMATION -
10CFR50.61 SCREENING CRITERION (RE: TAC NO. M83227)
Consumers Power Company (CPC) letter dated December 28, 1994 responded to the NRC's November 30, 1994 Request for Additional Information (RAI) concerning the Palisades reactor vessel (RV) and the 10CFR50.61 screentng criterion. Our December 28, 1994 submittal was the product of an extensive data search and used unique weld wire coil combination chemistry for determining the best estimate copper weight percent for welds fabricated with copper coated wire.
Subsequently, in a telephone conversation on January 9,1995, the CPC staff and the NRC staff discussed the content of that submittal.
Later on January 9,1995, the NRC issued an additional RAI.
The January 9, 1995 NRC RAI contains seven items.
All seven refer to our December 28, 1994 response.
Items 1-3 refer to the IP-2 Surveillan~_e_ Wel_q -~i:id
- --- - - ----lne IP-3-*Nozzle**-cutout-Weld-:-* Item* 'f arid -Item-*5 refer* to -the *Pal lsades Steam Generator welds.
Our response to those seven Items is included as. contains a revised statistical analysis description, a revised Table 5-7 and a revised figure 5-4.
The originals of these documents were submitted as part of Attachment 5 to our December 28,1994 submittal. They were revised in response to our January 9,1995 telephone discussion with the staff in regard to the median copper value.
9501240400 950116.!/
j~~O-=~ 05~~~H~(_ __ _ __ ~CMS ENERGY COMPANY contains a revised Table 5 and a revised Table 6.
They were originally submitted as part of Attachment 3 to our December 28, 1994 submittal. The originals had incorrectly reversed the high and low values of the HBRobinson data in the T30 comparison.
SUMMARY
OF COMMITMENTS There are no commitments in this submittal.
~&?~
Robert A. Fenech Vice President, Nuclear Operations CC Administrator, Region Ill, USNRC NRC Resident Inspector - Palisades Enclosures 2
ENCLOSURE 1 Consumers Power Company Palisades Plant Docket 50-255 RESPONSE TO THE JANUARY 9,1995 NRC RAI January 16, 1995
2032854232
- cE ~-llJCLEAR SRVCS F -852.34 P-002 JAN 16 '95 13:03
- NRC RAJ QUESTION NO. 1 Provide information to demoristrate that the weld (IP2 Surveillance Weld and IP-3 Nozzle *
- .Cutout) is either single or tandem arc.
RESPONSE
The Indian Point Unit 2 surveillance weld Was fabricated in ~ccordance with weld procedure specification WA-17765-042-2. This weld procedure specification calls for a RAC0-3 wire,
- Linde 1092 flux, and Ni-200 addition using a tandem arc process; The same WPS was called out for the vessel axial welds (l-04?A, B, and C)~.
The Indian Point Unit 3 ~ozzle cutout contained *a poqion of one of the 1-042A, B; and C *weld *
- seams. *The weld procedure specification was WA-3266-042-1 which calls for a RAC0-3 ~.
Linde 1092 flux, and Ni-200 addition ilsing a tandem ate process.
. These chelnistry values w~re supplied by Westinghouse without fabrication details, but* were thought to* be tandem arc welds. 1n* the absence ~f ~upporting evidence, the two welds were conservatively assumed to be single arc welds. Review of the fabrication records for the
.. December28 submittal showed these welds were fabricated using the tandem arc process..
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NRC RAI QUESTION NO. 2 Provide a sketch of the weld joint, showing weld sequence and location of specimens in the weld joint. Explain how it was determined that the measurements represent 3 unique combinations.
RESPONSE
The following sketch shows the typical welding sequence used to fabricate a reactor vessel nozzle shell course, nominally 11" thick. The shell course is comprised of three formed plate sections joined by three axial weld seams as shown.
SEAM A SEAM B SEAM C 1 7/16 11 5
5 5
4 4
4
. ~ 1'"
1 1
1 l
311 2
3 3
A typical finished dimension for the nozzle shell course is approximately 98 inches long.
Additional length for final machining of the shell coilrse as well as weld runouts would have been inc_luded for the welding. The minimum mass of weld metal required to fill the three shell
- course axial seams can be estimated as follows:
Mass of weld metal= Density* [3 *(Length* Width* Thickness)]
or Mass of weld metal_= 0.29 * [3 * (98 *1 7/16
- 11)] = 1348 pounds The coils of weld wire used in the tandem arc weld process were nominally 150 pounds each._
The required mass of weld metal corresponds to approximately 9 coils of weld wire.. Since tandem arc weld_ procedures were used a minimum of 10 coils would have been used. Since
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2032854232 CE NUCLEAR SRVCS F-852~34 P-003
. JAt4 16 '95 13: 03
- . records of criilchaiiges during the welding of the seams we~ not recorded, the weld seams cotild contain 5 or 6 ~ld wire.coil combinations (10-12 coils).
The welding of the three seams would have begun with the OD portion of each seam, indicated by numeral 1 on the sketch above. After depositing these three weld regions the ID portions of the seams were completed, designated as 2 and 3 in the sketch. Finally the OD portions of the three seams were completed, shown. as regions 4 and S in the sketch. The standard fabrication practice for incremental welding of axial shell course seams would have resulted in the five weld regions identified in the sketch.
The Indian Point 3 nozzle cutout contained _a section of one of the three axial seams.* The chemiCal analysis locations have been documented as being frOm the outside surface, l/2t and
in the weld seam represent the welding sequence regions S (outer surface), 4 (3/4t) and 1 (l/2t).
. Therefore, the samples from this weld represent 3 diStinct regions of the weld seam.
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Similarly, the Indian Point 2 surveillance weld chemical analyses were obtained from samples removed from locations in the range of 1-5 1/2" from the outer surface of the weld~ 5 112"-7" and 8-9". As shown schematically in the figure below, these locations through the thickness of the weld span weld regions 5 and 4, 1 and 2 and 3, respectively 1 7/1611 Outer Surface of Weld 5
5 5
1-5" from outer surface 4
4 4
11 11 f
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Weld Root 8-9" from outer 311 2
surface 3
3
2032854232
~._
.CE ~~lUCL_~AR SRl.)CS F-852 T-534 P-004*
JAN 16 '95 13:04
- NRC RAI QUESTIO_N NO~ 3
-~.-: *.:;'.".
Why is the teSt resUit fo; 04463 included in with the IP-2 Sur\\reillance Weld?.
RESPONSE
The test results fo~ 04463 could not.be determined to be independent of the IP-2 surveillance
- weld because the surveillance weld was a prolongation of the vessel weld. Further more, the 04463-result was v~ similar to the siirveillance specimen measurements. 'Therefore, the.
surveillance 'Weld chemical analysis results were used in conjunction with the 04463 measurement.
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2032854232 NRC RAI Q~S!ION NO~ *4* (PALISADES STEAM GENERATOR WELDS)
Explain ho~ it was detenninecI that the measurements represent 3 unique combinations (i.e.,., Y * **
and Z measurements on the B seam; Y and Z measurements on the A and C seams; all X.
. measurements).
RESPONSE
The grouping of Palisades SG w~lds into thiee regions was based on a combination of.
Microprobe Analysis of one weld.(seam C) shows discontinuities in the copper content in broad
- *. regions and suggestS that different weld coil combinations were used in these regions.. Region 1 (Attachment to J:'able 5-2}co:nsists of the "X" welds in the three seam5.. The~ are located near the inner wall and were grouped because of the welding sequence (steps 5, 6, 7 in Figure 3).
- They were probably deposited using the same coil combinations and iherefore the copper content * *
.
- should be similar.
~
. Region 2 consists of Seam A and C, Level Y and Z. These. were grouped primarily because of i~ * *
...l
consistent with the ~CP.readings in Seam C.. -
. c,
- . ~-
. Seam B, Level Y and Z were 8rouped as Region 3. Because of the lower copper content in this.
region compared to the other weld segments, it was believed that different coil combinations were used here., *
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~ *. The grouping or'the ICP data as described above is not the only groupfng; different * *
- _:
_combinations could have been.used.* Since the total number of coils for all.three seams was
- estimated at three pair$, groui)ing iri this fashion accounted for the no~ number of pairs. The.
grouping would have a sMall effect on the p~cted mean value of the coppet content of Heat
-W5214. If the ICP ~ts were groul>e<ibased S()le.ly on the.depth, the same mean value would.
be predicted beca~ the mean-value of each group is an average of each ICP reading. The.
- . *. *grouping* Used:40espass the F TeSt described in Response7to this set of questions,;
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NRC RAI QUESTION NO. 5 What are the chemical analysis methods reported in Table 5-4? What is the standard error (wt%
Cu).
RESPONSE
. The chemical analyses methods reported in Table 5-4 include both Inductively Coupled Plasma (ICP) from two different laboratories and Optical Emission Spectroscopy (OES) from a third
- laboratory. All of the results ide~tified as AEA are ICP analyses. AEA-1 a!_ld AEA-2 are ICP results from two different samples in adjacent sections taken from each of the weld seams. The results designated by ICP are ICP results from ABB-CE's Windsor Laboratories. Results*
designated by OES are OES results from AB~~CE's Chattanooga Laboratory. For all of the OES
. and ICP analyses performed by ABB-CE, certified standard reference materials supplied by NIST were used to verify the calibrations of the analytical equipment.
Both the ICP and OES results are from the same weld seam sections as the AEA-1 data.
However, these analyses do represent separate samples from approximately the sarp.e depth in the wel_d. The ICP results are offset by about 1/4" along the weld centerline from the AEA-1 results.
The OES results are from the opposite side of the weld seam section from the AEA-1 results, except in the cases where OES data are reported as OES+x and OES+y. In these cases, the OES analyses were performed on the opposite side of the same weld seam section but offset by the distances identified as x and yin Table 5-4 and referenced from the surface of the weld:
. The OES procedure used by the ABB-CE Chattanooga Laboratory is in accordance with ASTM E 415,Standard Test Method/or Optical Emission Vacuum Spectrometric Analysis a/Carbon.
. and Low Alloy Steel. The *standard deviations for the OES analyses are documented in ASTM E 415. For copper the relative standard deviation is 1.87% for average copper concentration of 0.435% and 2.00% for average copper concentration of 0.150%. In absolute terms the concentrations and standard deviations are 0.435 +/- 0.0081 and 0.150 +/- 0.003. These values..
span the range of copper concentrations for the Palisades SG welds. The standard deviations are consistent wi~ those defined by the standard ASTM method.
There is no corresponding standard test method used for the ICP analyses performed by the ABB-CE Windsor laboratory. The ICP analysis system performs and reports several integrations
- on each peak being analyzed for each sample. Review of the raw data outputs from the ICP analyses indicates that the percent relative standard deviation for each analysis is on the order of I%. Three replicate analyses were performed on each. sample and averaged to produce the I CP
- analysis results in Table 5-4. The percent relative standard *devia~ion was less than 1 % for. each of the three replicate analyses.
AEA Technoloo MATERIALS PERFORMANCE DEPARTMENT
. TESTrNG OF WELD METALS FOR CPCO (MPD/082)
TASK 2 MET ALLOGRAPHIC EXAMINATION Overview of Chemical Analysis Technique and Prt'iiti'i'":..,.... -.,....,,..., '" f"'"rr-'" n*t*"""(lt;t\\"c ownvmw OF Cll£MICAL ANAL\\'SIS 'l'Ja:t'H~lf.J'-IJ&; Al'IJ)
.* PRECISION/ACCURACY IN COPPER DETER\\UNATIONS PROCEDURE Pase l of 4 Material in the form of drillings (weighing* approximately 3-7gms) was taken from each test location. 0.2Sgms of these drillings were dissolved in acid to provide the test solution for chemical analysis by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP).
Three samples of each test solution are analysed and each sample is effectively analysed three.
times; i.e. three integrations of the ICP emission intensity are made. The average of the three
- integrations gives a value for each sample while the average of these values for the three samples
- gives the average composition for a specific location.
The standard error that is reported on test certificate$ is the standard deviation (a0 *1) of the three measurements from the mean divided by.../3 (Not the standard deviation of the total 9 integrations divided by..J9).
Analysis of the NIST standard was treated in the same manner except that three samples were dissolved and hence 9 measurements (each consisting of three integrations of the ICP emission.
iµtensity) were made and the standard error is the standard.deviation of the 9 measurements divided by "9.
The standard errors quoted for the samples are therefore an indication of the precision of the technique. The accuracy of the technique, and the sample results, is indicated by the reported results for the NIST standard compared to the certified value.s.
The measurements of the copper and nickel concentrations (plus associated standard errors) for*
the original analyses performed and the subsequent additional series of analyses are given on pageS 2 arid 3..
The Ce-rt.ificate of Analysis for the NIST Standard is reproduced on page 4.
G.Gage Materials Performance Department AEA TechnoloSY 12th January 1995 I of 4 *
---~
S00' 39t:ld MATERIALS PERFORMANCE DEPARTMENT ORIGINAL ANALYSIS SERIES Section through Large Weldmcnt 'A' Al/l/X Al/IN Al/l/Z Section thraugb Large Weldment 'B' Bl/WC" Bl/2/Y B112/Z.
Section through Trepan
'AJSG/A' A/SGJA/l/X*
AJSGJA/2N AJSGJA/2/Z Section through Trepan
'A/SGIB' AJSG/B/3/X A/SGIB/3/Y AJSG/'B.13/Z Scr:tian dlrOugh Trepan
'BISGIA'-
BISGIAl)JX BISO/All/Y BISGJ A/2/Z.
Section through Trepan
'B/SGIB' S/SG/Bl'2/X BISG/BllN*
B/SG/B/2/Z NIST STANDARD 362 Value 0.341 0.310 0.266 0.235 0.189 0.196 0.367 0.291 0.278 0.3S3 0.233 0.237 0.195 0.195 0.206 0.162 0.208 0.209 0.501 AEA Technolo1Y TESTING OF W~LDMET ALS FOR CPCO (MPD/082)
TASK 2 MET ALLOGRAPHIC EXAMINATION Overview of Chemical Analysis Technique and Precision/ Accuracy in Copper Determinations Page 2 of4 COPPER NICKEL Standard Value Standard Error Error 0.001 1.093 0.004 0.010 1.003 0.004 0.002 1:090 0.006 0.002 1.215 0.018 0.002 l.010 0.002
. 0.002 1.098 0.020 0.003
. 1.154
. 0.016 0.005 l.156 0.020 0.002 1.059.
0.011 0.001 1.203 0.022
<0.001 1.149 0.020
. 0.002 1.024 0.010 0.006 i:212 0.007 0.002 1.331 0.016 0.001 1.138 0.007 0.002 l.126 0.012 0.003 1.136*
0.011 0.004 l.307 0.023 0.003 0.591
- *0.004 2 of4
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. MATERIALS PERFORMANCE DEP AR.TMENT ADDITIONAL ANALYSIS SER1ES Value Section through Large WeJdmcnt 'A' ARJIX 0.328 ARl/Y 0.310 ARllZ 0.266 Section through Large Weldment 'B' BRl/X 0.198 BRl/Y 0.198 BRllZ 0.196 Section.through Trepan
. 'AJSGIA' AJSGJAJJIX 0.365 A/SO/A/3/Y 0.292 NSGJAJJfL
. 0.281 Section through Trepan
'AISOJB' A/SGJBll/X 0.359 AISG/B/J/Y 0.239 AJSG/B/2/Z.
0.228 Section thrOugh Trepan.
'BISQ/A' B/SG/A/J/X 0.191 B/SG/A/3/Y 0.192
- BISGIAJJfL 0.204 Section through Trepan
'BISGJB' B/SG.IB/3/X 0.165 B/SG/B/3/Y 0.203 BISGJBl3fL 0.209 NIST ST AND ARD 362 0.516 SS:0[ 56, 2! Nl:ff AEA Technoloc TESTING OF WELDMET ALS FOR CPCO (MPD/082)
TASK 2 MET ALLOGRAPHIC EXAMINATION Overview of Chemical Analysis Technique and Precision/ Accuracy in Copper Determinations Page 3 of4 COPPER.
NICKEL Standard Value Standard Error
- Error 0.006 1.116 0.018 0.005 l.006 0.017 o.oos l.104 0.018 0.003 l.092 0.017 0.00S 0.906 0.022 O.OOS l.057 0.026 0.004 1.193 0.012 0.004 l.127 0.015 0:006 l.066 0.019 0.002 l.204 0.009 0.002 0.960 0.007 0.002 1.107 0.010 0.002 l.256 0.017 0.003 l.292 0.018 0.003 0.998 0.018 o.oos 1.117 0.033 Q.005 1.088 0.029 0.005 1.292.
0.0)9 0.005 0.595 0.010 3 of 4
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~AEA MATERIALS PERFORMANCE DEPARTMENT I
AEA Technoloty TESTING OF WELD METALS FOR CPCO (MP0/082)
TASK 2 MET ALLOGRAPHIC EXM-llNA TION Overview of Chemical Analysis Technique and Precision/ A~curacy in Copper Determinations Paic 4 of 4 j)
~ ntiarlnl 3Jnstttutt of &tunharbs & <I2c~nalag11
<lrtrtiftmtt nf J\\nalust.s Standard Reference Ma.terial 362 AISt 94Bl7 St..t (Modlt!ed)
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.., A dio raw ol Illa coop...U~ aufyl.ic:ll pro,r;m. nc nZu lbuid Is llCC u;iectcd :o devla11 lrom tl!a 'tr~**
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Tiie O"iorsll dlnctioa ud caordillarima of tll1 lecUiaJ meuuramuu u :O.lST lndill& 10 :ercii!~tio: wen performed =do the 4iractioa GI 0. Mm.is. BJI. 5criha*r, I.1. Sliula. 111Ci J.L. W*ber, Jr.
- n. cecluaical ud &llpport *U!19CU iD"lllved Us 1111 prcpva1icia,' c:c~llftc.irioa. ud iuuuce of tliia Seu.Wei Raterua Malarial,.,,. coordlaated tlltoacla die OU!c:: or S1111Cbtd ll1forc1u:e bfa10,;.3~ by a.a. Mlcl:AeliJ ud
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(aoer) 4 of 4 S taAlcy 0. R~abeny. Chief Office ol Suacl.v X2 =sample means N1, N2 =sample sizes S*
= pooled estimate of standard deviation From Table 7-2 the value oft is computed to be 2.2679. This is compared. with t(a/2, N 1+Nz-2) which has a value at the 5% significance level (a) of 2.228. Since the sample t statistic is greater than 2.228, the n1:1ll hypothesis *of equality of population means is rejected. It should be noted that this t-test assumes equal population variances and normal parent distributions. Since the distribution is riot normal, the t-test. may be inappropriate.. As an alternative, a non-parametric test was also p~rformed. *This test was Fisher's Exact Test for 2x2 contingency tables. The contingency table for two samples is constructed by counting the number of data points for each sample which fall above (and below) the median of the pooled sample. The contingency table for the Palisades data is shown in Table 7-3. The Fisher's Exact Test computes the probability of a contingency table at least as adverse as that given, under the null hypothesis of populations of equivalent median. *The computations were performed with STATGRAPHICS VERSION 6 software.
The one-sided Fisher's test result showed a difference in the population central tendencies at the 9% significance level for a one-sided test and 18% for a two-sided test. The null hypothesis would lli2t be rejected at a 5% significance level as in the t-test. It is therefore
concluded that a hypothesis of equality in central tendency between the population of which the ste-am generator data is sampled and that from which the other. W5214 data is sampled is not
. necessarily rejectable based on the current data s~t.
The second issue concerns the variability comparison between the two data sets. Given that the selected steam generator samples represent three distinct welds, the variability within the steam generator data* set should be equivalent to that eXhibited by the other W5214 data which are
. separate welds. In terms of the hypothesis being tested, the variance of the sample 1 copper
- content is equal to the variance of the sample 2 copper content.
The F test (Reference 1) is used for this purpose. The F statistic is defined for two samples by:
. where: cr 1 =standard deviation of sample 1 cr2 = standard deviation of sample 2 N t> N2 = sample sizes The hypothesis of equality is rejected if F is greater than F(a/2, N 1-1, Nrl). The F for samples 1 and 2 is computed to be 1.418*. The value of F (.025, 2, 8) = 6.06, therefore, the null hypothesis of equal variances is not rejected at a 5% level of significance.
This result is not inconsistent with the surrnized conclusion that tht: steam generator data consists of separate welds as shown in Table 5-7.
REFERENCE 1 *.-. Crow, Davis, and Maxfield Statistics Manual, Dover,
- New York, 1960
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SAMPLE 1 TABLE 7-1 W5214 COPPER CONTENT DATASETS SAMPLE2 STEAM GENERA TOR OTHER
'0.226 0.150 0.277' 0.150 0.348 0.158' 0.159
(,
0.160 0.190 0.200
' 0.215 0.310 TABLE7-2 STATISTICS OF W5214 l)ATA SETS.
SAMPLE 1 SAMPLE2 POOLED MEAN
.28366
.188
.2119 STD DEV 0.0612 0.0514 0.0535 N
3 9
12 TABLE 7-3 CONTINGENCY TABLE FOR W5214 DATA SETS SAMPLE 1 SAMPLE2
- BELOW MEDIAN
.o 6
- ABOVE MEDIAN 3
3
ENCLOSURE 2 Consumers Power Company Palisades Plant Docket 50-255 REVISED PAGES OF ATTACHMENT 5 TO CPC SUBMITTAL DATED DECEMBER 28, 1994 January 16, 1994
2032854232 I/CE NUCLEAR SRVCS.
F -852.534 P-0~(;. __ :!.eN 15 ' '35 -13: 05 Staflstjral AnalJsil of the Cbemista:y of Heat W5214.
As.described earlier, the welding process 'consists of rUnning a bead down the weld groove, feeding.weld material from one or two 150 pound coils.
- Because*the coils are dipped into the coating bath in batches, the variation in copper content from coil to coil accountS for most of the
. spread in observations of weld copper coht:ent. This is supp0rted by the chemical analysis results which showed consistent ~pper. content within. the w~ld deposit from. one weld wire coil combination. DisContlliuitie8 in co~r* content are believed to be caused by different weld wire
. coil combinations. At the Delphi meeting held~
201 -i994, it was the conse~ 9f the
- participants that the variation of co~ along the length of the. weld bead.should be small. This iS because a sirigle weld read would have been deposited using a single coil or pair of coils. Iii COtJtrast,. ~r variation through the tluc~s could be greater than along a single bea~f'...* *
. becauSe. different coils ~ould have.been used: clunng the various stages of welding. nili; is based.
on the premise that ~per variation within a coil. (Le., along its length) will be less than coWer
- variation between eoils.
Table 5-5 summarizes ~ ~les.of WS214,seledect for weld wire coil combinations
- ,.}.
1 independence and gives the mCasured copper content of the samp~es. Also shown is the type *of
. weld process (single O~- ~)
amt de$Cription: summar}'.. Tue. basis fot the sample selection was ~ ind~
.. of the.,*~eld material.
Multlpie readings. of _the same weld wire coil combinations~~ a;e~ied td be a: single reading whe~-their inclusion as multiple independent sainples * ~~uld\\~iaS. ~, ~ts to.. that s~ific weld. wire coil combination.. Item* 8 of the
.. -.....:::~*. _.
~.
attachment~ Table;S~i-gives thC three weld ft'.gions from the Palisades steam generator:. These.
~eld regions*~-~~ in the i-espo~ to RAf Item 6. :.....
- The selection of the ~
~les was perf~rmed* in ~ ~o stq> Delphi Techniqu~
1
- In the first step, v~l material experts from ABB-CE reviewed the data pre8ented in Table 5-2 and selected independent samples. On 12/2019.4.' a larger group of ~xperts, including people working on reactor vessel llrtegrity.for six' different companies mei to review the method and data
. selection:
The attend3nce list is given as Table 5~. Starting with the original ABB-CE screening, the group reviewed aI1 the data given in Table 5-2, and supporting _information. They
reached a consensus that the data. given in Table 5-5 is the most likely representation of separate weld wire coil combinations for heat W5214.
Because tandem welds are a combination of two weld coils, the tandem w~lds are given a weight of two.
Table 5-7 gives the weighting of each sample. Table 5-7 also gives the mean and
- cumulative probability distribution that the copper content of a weld is less than or equal to a specific. percent (X).
The best estimate as suggested by 10CFR50.61 is the mean value. If the mean is used; the best estimate of the copper content of the Palisades reactor vessel (beat W5214) js 0.212% Cu. The mean credits the lower frequency, higher Cu content data; therefore, it is conservative. It has a 65 % probability quantile on the cumulative probability distribution. That means, on average, a 65 % chance that the welds will have less copper than the mean. The median for the tandem weid samples is 0.193 Cu. There is a 503 probability that the welds will have either a high~r
- or lower content than t.Qe *median value of 0.193 Cu.
Figure 5-4 gives the frequency distribution of the samples of tandem welds.* The distribution peaks at the low copper content and trails off as Cu 3 increases. It is not a normal distribution and the one sigma value has no meaning.
The phosphorus content of heat W5214 is estimated in Table 5-8.
The data for the specific samples is from Tables 5-2 and: 5-4 and is grouped in the same manner as the copper content
- data. The additionafsamples for which P content was available but Cu content was unknown has been added.
The 'best estimate (mean) Phosphorus content for heat W5214 is estimated as 0.0173.
. 1.
Gautschi, T.F., "Group Decision Making," Design News, April 4, 1983, Page 122.
2032854232
---~E NUCLEAR SRVC_S _
F-85211~c:;3_4_p--0-. 0-7--JA_N_1_6_'_'3_5 _1_3 :-0.
- TABLE~7 J
PROBABD..ITY DISTRIBUTION FOR COPPER'IN HEAT WS214 Analysis of Samples of Heat W5214 Sample Description Cu %
Weight Cu%
- Wt.
P(CU s x)
IP3 NOZZLE CUTOUT 0.15 2
0.3 IP3 NOZZLE CUTOUT
-0.1~
2 0.3 0.167 IP3 SURV 0.158 2
0.316 0.250 HBR2, TORUS-FLANGE 0.159 2
0.318 0.333 IP3 NOZZLE CUTOUT 0.16 0.32 0.417 IP2 SURV, REGION 3 0.19 2
0.38 0.500 IP2 SURV, REGION 1
-0.2 2
0.4 0.583 MEAN 0.2U 0.65 IP2 SURV. REGION 2 *
- 0.215 2
0.43-0.667 PAL SG. Region 3 0.226 2-0.452 0.750 PAL SG, Region 2 0.277 2
0.554 0.833 0.875
_1 0.285 OYSTER CREEK 1 SURV.
0.285
. 0.917 1
0.335 0.335 HBR2 SuRVEILLANCE -..
1.000 2
0.696 0.348 PAL S<;J, REG!PN,_t: __
Sum =
.. -~.:..::!:*.,-.-. ;_. *. ':"
24 5.086 J
- -r
~. ;....
- 0.212
~-
en w
- a.
8 6
4
~ 3 LL 0.
0 z 2
1 0
FIGURE 5-4 : HISTOGRAM OF COPPER CONTENT FOR HEAT W5214 (TANDEM WELDS ONLY) 0.140-0.179
.* 0.110-0.211. 0.220-0.251 0.210*0.299 0.300-0.331 0.340-0.371 COPPER CONTENT
ENCLOSURE 3 Consumers Power Company Palisades Plant Docket 50-255 REVISED TABLE 5 AND TABLE 6 OF ATTACHMENT 3 TO CPC SUBMITTAL DATED DECEMBER 28, 1994 January 16, 1995
Table 5: Comparison of W5214 Welds (68% Confidence Interval)
T30 Temperature Band Comparison (F)
DATA SET
-HIGH LOW MEAN Palisades Steam Generator
-36.9
-58.1
-47.5 Indian Point 2
-58.8
-74.4
-66.6 Indian Point 3
-60.7
-69.9
-65.3 H B Robinson
-73.9 -99.7
-86.8 Total Data*
-70.3
-85.7
-78.0 TSO Temperature Band Comparison (F)
DATA SET HIGH LOW.MEAN
- Palisades Steam Generator 1.4 -13.2
-5.9 Indian Point*2 Indian Point 3 H B Robinson Total Data*
-23.9 -35.9
-42.9
-49.5
. -30.1
-48.3
-38.9
-50.3
-29.9
-46.2
-39.2
-44.6 Upper Shelf Energy Comparison (ft-lbs)
DATA SET HIGH LOW MEAN Palisades Steam Generator 108.5 99.5 104.0 Indian Point 2 122.5 117.5 120.0 Indian Point 3 123.7 118.7 121.2 H B Robinson Total Data*
123.0 111.8. 117.4 118.4 114.6 116.5
- Total Data Set is the combination of the Indian P~int 2, Indian Point 3 and H B Robinson Data
Table 6: Comparison of W5214 Welds (95% Confidence Interval).
T30 Temperature Band Comparison (F)
DATA SET HIGH LOW MEAN Palisades Steam Generator
-25
-70
-47.5 Indian Point 2
-50.3 * -82.9
-66.6 Indian Point 3
-55.5
-75.1
-65.3 H B Robinson
-59.3 -114.3
-86.8
. Total Data*
-62.4
-93.6
-78.0 TSO Temperature Band Comparison (F)
DATA SET HIGH LOW MEAN Palisades Steam Generator 9.7
-21.5
-5.9 Indian Point2
-17.4 Indian Point 3
-39.2 H B Robinson Total Data*.
-19.7
-33.2
-42.4** -29.9
-53.2
-46.2
-58.7
-39.2
-56.0
-44.6_
Upper Shelf Energy Comparison (ft-lbs)
DATASET.
HIGH LOW MEAN Palisades Steam Generator 116.0 92.0 104.0 Indian Point 2 125.5 114.5 120.0 Indian Point 3 127.0 115.4 121.2 H B Robinson 130.4 104.4 117.4 Total Data*
120.3 112.7 116.5
- Total Data Set is the combination of the Indian Point 2, Indian Point 3 and H B Robinson Data :