ML17228B224

Forwards Addl Info for St Lucie Unit 1 Beltline Welds 2-203 A,B & C Use & Final Rept CEN-622, Generic Upper Shelf Values for Linde 1092,124 & 0091 Reactor Vessel Welds, Per GL 92-01,Rev 1

ML17228B224
Person / Time
Site:	Saint Lucie
Issue date:	07/25/1995
From:	Sager D FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17228B225	List: ML17228B224 ML17228B226
References
GL-92-01, GL-92-1, L-95-214, TAC-M83505, NUDOCS 9508020108
Download: ML17228B224 (14)

Text

i PRXORXTY (ACCELERATED RIDS PROCESSING)

.I REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCFQS~~N NBR: 9508020108 DOC; DATE: 95/07/25 NOTARIZED: NO DOCKET FAC.IL 50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 p AUTH. NAME AUTHOR AFFILIATION SAGER,D.A. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUMECT: Forwards addi info for St Lucie Unit 1 beltline welds 2-203 A,B & C USE & final rept CEN-622, "Generic Upper Shelf Values for Linde 1092,124 & 0091 Reactor Vessel Welds," per l

0 GL 92-01,Rev 1.

DISTRIBUTION CODE'O28D COPIES RECEIVED'LTR J ENCL SIZE TITLE: Generic Letter 92-01, Rev 1, Suppl 1 Responses (Reactor Vessel Struct 0 ~ /

NOTES RECIPIENT COPIES RECIPIENT .COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 PD 1 1 NORRIS,J 1 1 INTERNAL: ACRS 6 6 CENTER 1 1 1 NRR/DE/EMCB 2 2 RR/DRPE/.PBI 1 1 NUDOCS-ABSTRACT 1 1 OGC/HDS3 1 0 RES/DE/MEB 1 1 EXTERNAL: NOAC 1 1 NRC PDR 1 1 N

NOTE TO ALL "RZDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN 5DS (415-2083) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDI TOTAL NUMBER OF COPIES REQUIRED: LTTR 17 ENCL 16

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5 ~ P.O. Box 128, Ft. Piorco, FL 34954-0128 July 25, 1995 L-95-214 10 CFR 50.4 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 RE: St. Lucie Unit 1 Docket No. 50-335 Generic Letter 92-01 Revision 1 Belt-line Weld 2-203 Su lemental Informat'on NRC letter dated May 26, 1994, identified the need for additional data to confirm the USE at end-of-life (EOL) for belt-line weld 2-203, is greater than 50 ft-lb. The additional information was required to support a generic value FPL provided for the unirradiated USE. Your May 26, 1994, letter requested Florida Power and Light Company (FPL) to provide a schedule for providing the required data. On July 1, 1994 FPL provided the requested schedule for the additional data requested on St. Lucie Unit 1 belt-line weld 2-203.

The Combustion Engineering Owners Group (CEOG) performed an analysis of the USE values for a large data set of Linde 1092, 124, and 0091 weld fluxes. The CEOG submitted the results of the analysis in CEN-622, Generic Upper Shelf Values for Linde 1092,124, and 0091 Reactor Vessel Weeds, by Owners group letter (CEOG-95-353) dated July 7, 1995. A copy of the report is enclosed for your information. The report concluded through statistical analysis that the USE values grouped by flux type, were independent sets of data and therefore generic values based on these flux types is justified. The supporting information on grouping of data by flux type is attached.

Please contact us if there are any questions about this submittal.

Very truly yours, D. A. er Vice e ident St. Lu 'e Plant DAS/GRM Attachments cco Stewart D. Ebneter, Regional Administrator, Region Senior Resident Inspector, USNRC, St. Lucie Plant II, USNRC 3 f (' F,, 9508020i 08 950725 PDR ADOCK 05000335 go~<

P PDR L an FPL Group company

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~ I St. Lucie Unit 1 Docket No. 50-335 Generic Letter 92-01 Revision 1 Belt-line Weld 2-203 Supplemental Information ATTACHMENT 1

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I P ADDITIONAL INFORMATION FOR THE ST ~ LUCIE UNIT 1 BELTLINE WELDS 2-203 AiB & C UPPER SHELF ENERGY NRC Re est - St Lucie 1 TAC No. M83505 The NRC issued a letter to Florida Power and Light Company (FPL) on May 26, 1994'ith their tabulation of the information supplied for Generic Letter (GL) 92-01 concerning the St Lucie Unit 1 & Unit 2 reactor vessels. The letter requested that FPL review this information for accuracy for both units and respond with any inconsistencies. FPL reviewed the data by the NRC and provided a response~ with a schedule for other requested items to be provided.

The other items are described below:

".... For St. Lucie Unit 1, we have determined that additional data is required to confirm that the upper shelf energy (USE) at the end of life (EOL) for one of your beltline materials, weld 2-203 is greater than 50 ft-lb because you have provided a generic mean value for the unirradiated USE. These types of values are unacceptable because they do not consider material variability" (of other weld flux types). "When the unirradiated USE for a particular material has not been determined, you may set the USE equal to the lower tolerance limit calculated for the group of similar materials....."

Res onse to RAI on Weld 2-203 St Lucie Unit 1 In 1993, Florida Power and Light Co. responded to the GL 92-01 RAI~

and included a generic upper shelf energy (USE) value4~ for the St Generic Letter (GL) 92-01, Revision 1, Reactor Vessel Structural Integrity, St. Lucie Units 1 and 2 (TAC NOS.

M83505 and M83506), Letter from NRC to J.H. Goldberg; May 26, 1994.

FPL Letter, L-94-169, St. Lucie Units 1 and 2 Docket No.

50-335 and 50-389, Generic Letter 92-01, Revision 1, Response to Request for Additional Information, D. A.

Sager to NRC, July 1, 1994.

St. Lucie Units 1 and 2 Request for Additional Information Generic Letter (GL) 92-01, Revision 1, (TAC NOS. M83505 and M83506), Letter from NRC to J.H.

fields, Goldberg; July 28, 1993.

FPL Letter, L-93-286, St. Lucie Units 1 and 2 Docket No.

50-335 and 50-389, Generic Letter 92-01, Revision 1, Response to Request for Additional Information (RAI), D.

A. Sager to NRC, November 15, 1993.'pper Shelf Energy Information Pertaining to the St.

Luci e Unit 2 and Unit 2 Reactor Vessel ABB-Combustion Engineering, F-MECH-93-050/L-MECH-93-015,

Lucie Unit 1 intermediate shell longitudinal welds (2-203 A, B, C).

The analysis did not address data from other weld flux types to justify their exclusion from the generic value so more information was requested. The Combustion Engineering Owners Group (CEOG) performed an analysis of USE values for a large data set of Linde 124, 0091, and 1092 weld fluxes . The report concluded through statistical analysis that the USE values, grouped by flux type, were independent sets of data and therefore generic values based on these flux types were justified. This grouping of data by flux type accomplishes the following:

1) A reduction of variability for each data set when compared to the overall population of USE data. Using just Linde 124 USE values allows for a tighter data set and the associated standard deviation.

2) The determination of a conservative generic USE for our material based on both this statistical data and on specific material test data available for the St Lucie Unit 1 weld seams 2-203 A, B and C.

The St. Lucie Unit 1 weld seams 2-203 A, B & C were all fabricated with a single electrode process using the same weld wires A8746 and 34B009 with Linde 124 flux noted in Table 1. The mean USE value of the Linde 124 flux type data set, is 102.3 ft-lbs and is based on the same 68 point data set previously reported '. The standard deviation for this data set is 9.4 ft-lbs.

The 1/4T end of life (EOL) fluence previously reported. in Reference 2 was a conservative vessel maximum. The 1/4T location specific fluence (adjusted for the azimuthal location of the weld seams) for the axial welds 2-203A, B & C is reported in Table 2. Using the Cu, generic mean USE value from Table 1 and the St. Lucie Unit 1 actual azimuthal (EOL) 1/4 T vessel fluence at these longitudinal weld locations, the decrease in USE can be predicted from Figure 2 September 28, 1993.

Generic Upper Shelf Values for Iinde 2092, l24 and 0091 Reactor Vessel Velds, Task 839, ABB-Combustion Engineering Owners Group, CEN-622, June, 1995.

FPL Letter, L-93-286, St. Lucie Units 1 and 2 Docket No.

50-335 and 50-389, Generic Letter 92-01, Revision 1, Response to Request for Additional Information (RAI), D.

A. Sager to NRC, November 15, 1993.

Shelf Energy Information Pertaining to the St.

IUpper uci e Uni t 2, and Uni t 2 Reactor Vessel Wel ds, ABB-Combustion Engineering, F-MECH-93-050/L-MECH-93-015, September 28, 1993.

of Regulatory, Guide 1.99 revision 20. The predicted EOL USE for welds 2-203A, B, C welds using the generic mean is reported in line 1 of Table 2 and is not predicted to fall below the 10 CFR 50 Appendix G, 50 ft-lbs limit within the license life.

Since no NRC regulation exists on how to determine a conservative estimate of USE from generic data, the same procedure suggested in RG 1.99 section 1.1 of mean plus one standard deviation for chemistry values will be used. For an USE value the conservative value would be mean minus one standard deviation (mean USE cr).

This procedure will yield a conservative result because the RG 1.99 USE reduction correlation is based on the lower bound of all data.

Using a conservative estimate of USE (mean USE 0) of 92.9 ft-lbs, welds 2-203A, B, and C will not fall below the 10 CFR 50 Appendix G, 50 ft-lbs limit at EOL. Taking an extremely conservative approach and repeating the same EOL 1/4T USE calculation using the mean USE 2a as a lower bound USE value of 83.5 ft-lbs, welds 2-203A, B, and C will not fall below the 10 CFR 50 Appendix G, 50 ft-lbs limit at EOL. These EOL 1/4T USE values are show in Table 2 lines 2 and 3 respectively.

The lower bound USE value of mean USE-2a is very conservative for the 2-203 A, B and C welds when available Charpy data is considered. Charpy 10'F data compared to actual USE supplies a strong inference that the actual upper shelf is higher than the low bound. Actual Charpy data for the 2-203 A, B and C welds at 10'F provided average results 70 ft-lbs' Examination of EPRI Report NP-2428, Irradiated Nuclear Pressure Vessel Steel Data Base", for Linde 80, 124, 1092 and 0091 weld data indicates that the 10'F results are typically in the mid-transition region of the Charpy curve and well below the upper shelf in energy value. A summary of data from 20 welds including 10'F energy, USE, a ratio of the two and a difference between the two energy values is presented in Table 3 and listed in ascending order of 10'F Charpy energy. The ratio of USE to 10'F energy ranged from 1.34 to 2.52 for this data set with an average delta between USE and 10'F energy of 43.1 ft-lbs.

Another source of full Charpy curves is the CE response to the NRC I&E bulletin 78-12' A summary of data from 18 Linde 124 flux US NRC Regulatory Guide 1.99, Radiation Embrittlement of Reactor Vessel Materials, Revision 2, May 1988.

10 FPL Letter, L-77-308, St. Iucie Unit l Reactor Vessel Material Information, R. E. Uhrig to D. K. Davis, NRC, September 30, 1977.

Irradiated Nuclear Pressure Vessel Steel Data Base, EPRI Report NP-2428, June 1982.

12 Atypical Veld Material In Reactor Pressure Vessel fields, CE Response to I&E Bulletin 78-12, June 8, 1979.

welds including 10'F energy, USE, a ratio of the two and a difference between the two energy values is presented in Table 4 and listed'in ascending order of 10'F Charpy energy. Although this 18 point data set is not as large as the 68 data points that determined the generic mean ', the lowest USE (82.7 ft-lbs) of the data set is included and both the average USE value and the generic USE mean are almost identical. The ratio of USE to 10'F energy ranged from 1.15 to 1.75 for this data Linde 124 only data set.

This data set also showed the 10'F was in the mid transition region of the Charpy curve. Also included is a ratio of the actual 10'F data for the St. Lucie Unit 1 welds 2-203 compared to the generic mean USE value minus 1 and 2 standard deviations of 1.33 and 1.19 respectively. The average delta between USE and 10'F energy for this Linde 124 only data set is 27.6 ft-lbs.

All the full Charpy curves for the welds in Table 3 and 4, had an upper shelf that did not, start until beyond 100'F. When both data sets are considered no Linde flux welds with a 10 F Charpy energy of greater than 66 ft-lbs had a USE of < 92.9 ft-lbs (the proposed generic mean USE 1cr applicable for the St. Lucie Unit 1 welds 2-203). Applying this same ratio to the proposed generic mean USE-1cr (92.9 ft-lbs) for the St. Lucie welds 2-203 A, B and C provides a ratio of 1.33. Comparing this ratio of 1.33 to the 18 Linde 124 flux welds in Table 4 shows that although this ratio is not the lowest, the only data with a lower ratio have an USE value higher than that proposed for the St Lucie Unit 1 welds 2-203 of 92.9 ft-lbs. Of the 5 data points with a ratio below 1.33, all but one have an USE >102.3 ft-lbs (Linde 124 generic mean USE in reference

6) and non have a USE below the proposed generic mean USE lo (92.9 ft-lbs) for the St. Lucie Unit 1 welds 2-203 A, B and C demonstrating the excessive conservatism associated with the mean-2a value.

Comparison of the deltas between USE and 10'F energies for the Linde 124 data set in Table 4 and the St Lucie Unit 1 weld material shows that the delta for the generic mean 1cr (92.9 ft-lbs) is 22.9 ft-lbs and is below the average delta for the data set. Of the six data points with deltas < 22.9 ft-lbs only one has a USE lower than the proposed 92.9 ft -lbs. Additionally no data has a delta between USE and 10'F energy that is below the 13.5 ft-lbs observed for mean 2cr (83.5 ft-lbs) demonstrating the excessive conservatism associated with the mean 2a value.

Therefore a USE value mean 1u (92.9 ft-lbs) is a conservative estimate of USE for the St. Lucie Unit 1 welds 2-203 A, B and C.

Generic Upper Shelf Values for Linde 1092, 124 and 0091 Reactor Vessel fields, Task 839, ABB-Combustion Engineering Owners Group, CEN-622, June, 1995.

~summar A generic mean value of USE for the St. Lucie Unit 1 Welds 2-203 has been determined to be 102.3 ft-lbs based on the mean of 68 similar flux type welds. A conservative value of USE (mean USE-1cr) of 92.9 ft-lbs as applicable for the St. Lucie Unit 1 weld 2-203 A, B and C. Using a conservative value of USE>>(mean USE 1o) of 92.9 ft-lbs for the calculation of predicted EOL irradiated USE, welds 2-203A, B, and C will not fall below the 10CFR50 Appendix G, 50 ft-lbs limit at EOL. The conservative generic USE value of mean USE 1v (92.9 ft-lbs) is justified when considering weld specific average 10'F data at 70 ft-lbs.

TABLE 1 ST. LUCIE UNIT 1 REACTOR VESSEL BELTLINE 'WELD MATERIAL DROP CHARPY WELD LOCATION HEAT ¹ FLUX FLUX  % Cu  % Ni WEIGHT USE TYPE LOT (4F) (FT-LB)

Intermediate A8746/ Linde 3878/ 0.19 0. 10 NA -56 102. 314 Shell Long 34B009 124 3688 (b) (b) (a)

Seam (2-203 A, B, C)

NA Not Ava3.lable a Generic data for CE submerged arc welds using Linde 0091, 1092 and 124 Flux per 10CFR50.61 Best estimated Cu and Ni content (low nickel type wire)'ABLE 2

ST ~ LUCIE UNIT 1 REACTOR VESSEL BELTLINE WELD 2-203 EOL USE PROJECTION Material Initial USE ft.lb  % Cu EOL 1/4 T Fluence Reg Guide 1.99 rev.2 EOL USE (Transverse) (Ref. 4) (n/cmr) (% reduction ) (ft-Ib)

Intermediate 102.3 0.19 1 43x loo 36% ,

65.5 shell long welds (mean value)

(2-203 A, B, C)

Intermediate 92.9 0.19 1.43 x 10'o 36% 59.5 shell long welds (Conservative (2-203 A, B, C) Estimate, mean - lo)

Intermediate 83.5 0.19 1 43 x 10>o 36% 53.4 shell long welds (lower bound, (2-203 A, B, C) mean -2o)

Generic Upper Shelf Values for Iinde 2092, 224 and 0091 Reactor Vessel, Welds, Task 839, ABB-Combustion Engineering Owners Group, CEN-622, June, 1995.

15 FPL Letter, L-93-286, St. Lucie Units 1 and 2 Docket No.

50-335 and 50-389, Generic Letter 92-01, Revision 1, Response to Request for Additional Information (RAI), D.

A. Sager to NRC, November 15, 1993.

Table 3:

Selected 'Held Charpy Data from EPRI Report NP-2428'PRI Report NP2428 On initial USE of RV Surveillance acids 10'F Measure Ratio of USE Minus Vessel Flux 104F ft Actual/ USE USE to 10'F energy Vendor Page ¹ Type Ib Estimate (ft-Ib) 10'F ft-Ib'ftAb)

B&W 2-92 L80 25 no-est 63 2.52 B&W 2-72 L80 no-est 68 2.27 B&W 2-110 L80 31.3 yes-act 65 2.08 B&W 1-139 L80 31.7 yes-act 63.6 2.01 31.9 CB&I 1-105 L1 24 33 20'F data 77.3 2.34 B&W 2-165 L80 34.7 yes-act 66.3 1.91 31.6 B&W 1-170 L80 38.3 yes-act 69.5 1.81 31.2 B&W 1-152 L80 39.3 yes-act 70 1.78 30.7 B&W 1-109 L80 40.6 30'F data 71.4 1.76 B&W 2-57 L80 43.7 yes-act 76.3 1.75 32.6 CE 1-205 L1 092 48 no-est 112 2.33 CE 1-122 L1 092 49.7 yes-act 106.7 2.15 57 CE 1-118 L1 092 52 yes-act 118.3 2.28 CE 1-220 L1 092 55 no-est 111.3 2.02 CE 1-231 L124 61.3 yes-act 93.7 1.53 32.4 2-19 L1092 62.7 yes-act 125.7 2.00 CE 3-101 L1 092 68.7 yes-act 112.7 1.64 CE 1-100 L1 092 78.7 yes-act 111 1.41 32.3 CE 1-96 L1 092 81.7 yes-act 149 1.82 CE 1-195 L0 091 109 yes-act 146.3 1.34 37.3 AVERAGE 93.9 1.94 43.1 Irradiated Nuclear Pressure Vessel Steel Data Base, EPRI Report NP-2428, June 1982.

j Table 4:

Linde 124 Weld Charpy Data from CE Response to NRC Z&E Bulletin 78-12" with St. Lucie Unit 1 Data for Comparison.

"Atypical Weld Material in RPV Welds" - CE, tune 8, 1979 Information Requested By NRC i&E Bulletin No. 78-12 Report 10'F Section Measure Ratio of USE Minus Vill Flux 10'F ft Actual/ USE USE to 10'F energy Wire Ht Page ¹ Type Ib Estimate (fthm b) 104F ftAb (fthm b)

E5690B 195 L124 52 nest 89.3 37.3 90144 221 L124 yes-act 1.75 90211 RVG1 391 L124 no-est 82.7 91762 L124 58 yes-act 1.52 89833 218 L124 64 no-est 95.7 1.50 31.7 215 L124 6B ncH.st 88.6 1.34 3P 7317 192 L124 68 no-est 103 1.51 3P 7313 198 L124 70 no-est 102.7 1.47 32.7 651A 708 231 L124 70 new.st 96.3 1.38 4P 7869 L124 72 nest 97.3 1.35 5P886B 212 L124 75 no-est 107.7 1.44 32.7 3P 8013 237 L124 75 no-est 93.7 1.25 18.7 186 L124 81 nest 110.7 1.37 4P 7927 L124 83.7 yes-act 115.7 1.38 32 3P 7802 L124 87 no-est 109.7 1.26 3P 7246 189 L124 88 no-est 5 108 1.23 LP5P9744 242 L124 91 no-est 109 1.20 18 4P 8632 234 L124 95 no-est 109.3 1.15 14.3 AVERAGE 72.4 100.0 1.41 27.6 10OF Mean - Ratio of USE Minus Flux 10'F ft- Measure 1 std USE to 10'F energy Plant Weld ¹ Type Ib Actual dev. 10'F ft-Ib (fthm b)

Weld 2-St Lucie1 203A,B,C L124 70 yes-act 1.33 Mean-2 std de V.

Weld 2-St Lucie 1 203A,B,C L124 70 yes-act 1.19 13.5 Data From CE RVG Task (iawest USE in Linde 124 Data Set)

Atypical Weld Material In Reactor Pressure Vessel Welds, CE Response to Z&E Bulletin 78-12, June 8, 1979.