ML17354A878
| ML17354A878 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 04/07/1998 |
| From: | Jabbour K NRC (Affiliation Not Assigned) |
| To: | Plunkett T FLORIDA POWER & LIGHT CO. |
| References | |
| TAC-MA0579, TAC-MA0580, TAC-MA579, TAC-MA580, NUDOCS 9804130166 | |
| Download: ML17354A878 (19) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055&4001 Apri 1 7, 1998 Mr. T. F. Plunkett, President Nuclear Division Florida Power and Light Company P. O. Box14000 Juno Beach, FL 33408-0420
SUBJECT:
REQUEST FOR ADDITIONALINFORMATIONREGARDING REACTOR
-- "- " PRESSURE VESSEL INTEGRITYATTURKEY POINT.UNITS 3 AND4-(TAC NOS. MA0579 AND MA0580)
Dear Mr. Plunkett:
Generic Letter (GL) 92-01, Revision 1, Supplement 1, "Reactor Vessel Structural Integrity" was issued in May 1995. This GL requested licensees to perform a review of their reactor pressure vessel (RPV) structural integrity assessments in order to identify, collect, and report any new data pertinent to the analysis of the structural integrity of their RPVs and to assess the impact of those data on their RPV integrity analyses relative to the requirements of Section 50.60 of Title 10 of the od f
e al u
i (10 CFR 50.60), 10 CFR 50.61, Appendices G and H to 10 CFR Part 50 (which encompass pressurized thermal shock (PTS) and upper shelf energy (USE) evaluations), and any potential impact on low temperature overpressure (LTOP) limits or pressure-temperature (PT) limits.
After reviewing your response, the U.S. Nuclear Regulatory Commission (NRC) issued you a letter dated August 5, 1996.
In this letter the NRC requested, in part, that you provide an assessment of the application of the ratio procedure, as described in Position 2.1 of Regulatory Guide 1.99, Revision 2, to your PT limits curves and LTOP limits.
Subsequent to issuing this letter, the NRC conducted an inspection of Framatome Technologies, Inc. (FTI) in May 1997. This inspection focused on obtaining all available RPV weld chemistry data for RPVs fabricated by Babcock 8 Wilcox Company (B8W). As a result of this inspection, additional data were identified which may affect previous RPV integrity analyses supplied by licensees with B8W fabricated RPVs.
As a follow-up to the letter and the FTI inspection, and in order to provide a complete response to Items 2, 3 and 4 of the GL, the NRC requests that you provide a response to the enclosed request for additional information (RAI)within 90 days of receipt of this letter. This response should include application of the ratio procedure in the assessment of surveillance data from welds.
Ifa question does not apply to your situation, please indicate this in your RAI response, along with your technical basis and, per GL 92-0t, Rev. 1, Supp. t, provide. certification that previously submitted evaluations remain valid.
9804i30166 980407 PDR ADOCK 05000250 P
T. F. Plunkett April 7, 1998 The information provided will be used in updating the Reactor Vessel Integrity Database (RVID). Also, please note that RPV integrity analyses utilizing newly identified data could result in the need for license amendments in order to maintain compliance with 10 CFR 50.60, 10 CFR 50.61 (PTS), and Appendices G and H to 10 CFR Part 50, and to address any potential impact o'n LTOP limits or PT limits. Ifadditional license amendments or assessments, are necessary, the attached RAI requests that you provide a schedule for such submittals.
Ifyou should have any questions regarding this request, please contact me at (301) 415-1496.
Sincerely, (Original signed by)
Kahtan N. Jabbour, Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
As Stated Docket Nos. 50-250 and 50-251 DISTRIBUTION:
--Docket File PUBLIC
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PDII-3/LA PDII-3/D NAME KJABBOUR:cw BCLAYTONFHEBDON DATE
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/I'/0/98 Q/ 7/98 OFFICIAL RECORD COPY DOCUMENT NAME: G:LTURKENMA0522.RAI
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T. F. Plunkett The information provided willbe used in updating the Reactor Vessel Integrity Database (RVID). Also, please note that RPV integrity analyses utilizing newly identified data could result in the need for license amendments in oider to maintain compliance with 10 CFR 50.60, 10 CFR 50.61 (PTS), and Appendices G and H to 10 CFR Part 50, and to address any potential impact on LTOP limits or PT limits. Ifadditional license amendments or assessments are necessary, the attached RAI requests that you provide a schedule for such submittals.
Ifyou should have any questions regarding this request, please contact me at (301) 415-1496.
Sincerely, Kahtan N. Jabbour, Project Manager Project Directorate ll-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
As Stated Docket Nos. 50-250 and 50-251
V
Mr. T. F. Plunkett Florida Power and Light Company I
TURKEY POIN PLANT CC:
M. S. Ross, Attorney Florida Power 8 Light Company P.O. Box 14000 Juno Beach, FL 33408-0420 John T. Butler, Esquire Steel, Hector and Davis 4000 Southeast Financial Center Miami, Florida 33131-2398
. -Mr. Robert J; Hovey; Site Vice President Turkey Point Nuclear Plant Florida Power and Light Company 9760 SW. 344th Street Florida City, FL 33035 Armando Vidal County Manager Metropolitan Dade County 111 NW 1 Street, 29th Floor Miami, Florida 33128 Senior Resident Inspector Turkey Point Nuclear Generating Station U.S. Nuclear Regulatory Commission P.O. Box 1448 Homestead, Florida 33090
'Mr. Bill Passetti Office of Radiation Control Department of Health and Rehabilitative Services 1317 Winewood Blvd.
Tallahassee, Florida 32399-0700 Mr. Joe Myers, Director Division of Emergency Preparedness Department of Community Affairs 2740 Centerview Drive Tallahassee, Florida 32399-2100 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, SW., Suite 23T85 Atlanta, GA 30303-3415 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304 Plant Manager Turkey Point Nuclear Plant Florida Power and Light Company
'9760 SW. 344th Street Florida City, FL 33035 Mr. H.N. Paduano, Manager Licensing 8 Special Programs Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408;0420 Mr. Gary E. Hollinger Licensing Manager Turkey Point Nuclear Plant 9760 SW. 344th Street Florida City, FL 33035 Mr. Kerry Landis U.S. Nuclear Regulatory Commission 61 Forsyth Street, SW., Suite 23T85 Atlanta, GA 30303-3415
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~ec io~1 Assessment of Best-Estimate Chemistry The staff recently received additional information that may affect the determination of the best-estimate chemistry composition for your reactor pressure vessel (RPV) welds or your surveillance weld material. This data was provided bg Framatome Technologies, Inc. (FTI) in letters. from.Mr..Matthew J.-DeVan to. Mr..Barry J.-Elliot,-U.S. Nuclear. Regulatory Commission-(NRC), dated June 6, 1997 (INS-97-2262), June 19, 1997 (INS-97-2450), and July 10, 1997 (INS-97-2741).
In addition, it is the NRC staffs understanding that an evaluation of this data was provided to members of the 88W Owners Group; Mr. R. E. Jaquin, Rochester Gas and Electric; and Mr. P. S. Askins, Tennessee Valley Authority; via letter dated June 30, 1997 (INS-97-2526).
Based on this information, in accordance with the provisions of Generic Letter (GL) 92-01, Revision 1, Supplement 1, the NRC requests the following:
An evaluation of the information in the references above and an assessment of its applicability to the determination of the best-estimate chemistry for all of your RPV beltline welds.
Based upon this reevaluation, supply the information necessary to completely fillout the data requested in Table 1 for each RPV beltline weld material.
Also provide a discussion for the copper and nickel values chosen for each weld wire heat noting what heat-specific data were included and excluded from the analysis and the analysis method chosen for determining the best-estimate.
Ifthe limiting material for your vessel's pressurized thermal shock/pressure temperature (PTS/PT) limits evaluation is not a weld, include the information requested in Table 1 for the limiting material also.
Furthermore, you should consider the information provided in Section 2.0 of this request for additional information (RAI) on the use of surveillance data when responding.
With respect to your response to this question, the staff notes that some issues regarding the evaluation of the data were discussed in a public meeting between the NRC staff, Nuclear Energy Institute (NEI), and industry representatives on November 12," 1997. This meeting is documented in a summary dated November 19, 1997, "Meeting Summary for November 12, 1997 Meeting with Owners Group Representatives and NEI Regarding Review of Responses to Generic Letter 92-01, Revision 1, Supplement 1 Responses" (Reference 1).
The information in Reference 1 may be useful in helping you to prepare your response.
In addition to the issues discussed in the referenced meeting, you should also consider what method should be used for grouping sets of chemistry data (in particular, those from weld qualification tests) as being from "one weld" or from multiple weld
. This is an important consideration when a mean-of-the-means or coil-weighted average approach is determined to ENCLOSURE
be the appropriate method for determining the best-estimate chemistry.
Ifa weld (or welds) were fabricated as weld qualification specimens by the same manufacturer, within a short time span, using similar welding input parameters, and using the same coil (or coils in the case of tandem arc welds) of weld consumabtes, it may be appropriate to consider all chemistry samples from that weld (or welds) as samples from "one weld" for the purposes of best-estimate chemistry determination.
Ifinformation is not available to cocofirm the aforementioned details, but sufficient evidence exists to reasonably assume the details are the same, the best-estimate chemistry should be evaluated both by assuming the data came from "one weld" and from an appropriate number of "multiple welds". Ajustification should then be provided for the chosen assumption when the best-estimate chemistry was determined.
~Se LiiL20 Evaluation and Use of Surveillance Data The chemical composition reports referenced in Section 1.0 include updated chemistry estimates for heats of weld metal. These reports provide information regarding a best-estimate value and the source of the data used in estimating the. chemical composition of the heat of material. This permits the determination of the best-estimate chemical composition for the various sources of data including surveillance welds. Since the evaluation of surveillance data rely on both the best-estimate chemical composition of the RPV weld and the surveillance weld, the information in these reports may result in the need to revise previous evaluations of RPV integrity (including LTOP setpoints and PT limits) per the requirements of 10 CFR 50.60, 10 CFR 50.61, and Appendices G and H to 10 CFR Part 50.
Based on this information and consistent with the provisions of GL 92-01, Revision 1, Supplement 1, the NRC requests the following:
That (1) the information listed in Table 2, Table 3, and the chemistry factor from the surveillance data be provided for each heat of material for which surveillance weld data are available ~ad a revision in the RPV integrity analyses (i.e., current licensing basis) is needed or (2) a certification that previously submitted evaluations remain valid.
Separate tables should be used for each heat of material addressed.
Ifthe limiting material for your vessel's PTS/PT limits evaluation is not a weld, include the information requested in the tables for the limiting material (ifsurveillance data are available for this material).
The information discussed in Section 1.0 of this RAI regarding the chemistry reports should be considered in this response along with the following questions and comments.
AIIsurveillance program results for the heats of material in an RPV should be considered in evaluating its integrity regardless of source per 10 CFR 50.61, "Surveillance program results means any data that demonstrates the embrittlement trends for the limiting beltline material, including but'not limited to data from test reactors or from surveillance programs at other plants with or without surveillance program integrated per 10 CFR 50, Appendix H." Ifany of the data provided in Table 2 are not used in the calculation of the embrittlement trend fc r a particular RPV weld, the technical basis for not including/using the data should be provided.
When assessing credibility of surveillance data that come from more than one source, adjustments to the surveillance data may be needed to account for differences in the chemical composition and irradiation environment of the different sources consistent with the requirements in 10 CFR 50.61. A method for accounting for these differences is discussed in Reference 1.
Based on the information provided in Table 2, the credibility of the surveillance data can be evaluated.
The results of these analyses including the slope of the best fit line through the surveillance data can be provided in a format similar to that of Table 3. Ifthe method for adjusting and/or normalizing the surveillance data when assessing credibility differfrom the methods documented inReference.1, provide.the technical. basis for. the. adjustment.and/or the normalization procedure.
Ifthe chemical composition of the surveillance weld is not determined in accordance with Reference 1 (i.e., the mean of all chemistry analyses performed on the surveillance weld), provide the technical basis for the estimate.
When determining the chemistry factor for an RPV weld from surveillance data, adjustments to the surveillance data may be needed to account for differences in the chemical composition and irradiation environment between the surveillance specimens and the vessel being assessed consistent with the requirements in 10 CFR 50.61. A method to account for these differences is provided in Reference 1.
In addition, 10 CFR 50.61(c)(2) specifies that licensees shall consider plant-specific information (e.g., operating temperature and surveillance data) to verify that the RT>> for each vessel beltline material is a bounding value.
Regulatory Guide (RG) 1.99, Revision 2 describes two methods for determining the amount of margin and the chemistry factor used in determining RTiipy. Position 1.1 describes the use of the Generic Tables in the RG. Position 2.1 describes the use of credible surveillance data.
Ifthe surveillance data are credible, the o~ may be reduced in half to calculate the margin term and the chemistry factor is to be determined from the best-fit line of the surveillance data.
Ifthe evaluation of the surveillance data indicate that the surveillance data set is not credible and the measured values of BRTgpy are less than the projected mean from the Tables pIus the generic 2o~, the chemistry factor may be calculated using either Position 1.1 or Position 2.1; however, the full margin term must be applied. The method chosen must bound all the surveillance data to be in compliance with 10 CFR 50.61(c)(2).
Based on the information provided in Table 2 along with the best-estimate chemical composition of the heat of material and the irradiation temperature of the plant whose vessel is being assessed, the chemistry factor of the RPV weld can be determined.
Note that the adjusted ART>>, for a particular surveillance data point may be one value when determining credibility and another value when determining the chemistry factor as a result of the different normalization procedures.
Ifthe method for adjusting and/or normalizing the surveillance data, when determining the chemistry factor differs from the methods documented in Reference 1,
provide the technical basis for the adjustment and/or the normalization procedure:
In a meeting between the staff and industry representatives at the NRC on February 12, 1998, an industry representative requested clarification as to when the ratio procedure should be used to evaluate surveillance data.
The ratio procedure is described in the PTS rule and RG 1.99,
Revision 2. The ratio procedure is used to adjust the measured value ofhRT>> to account for differences in the chemical composition between the surveillance weld and the vessel beltline weld. The PTS rule and RG 1.99, Revision 2 indicate that when there is clear evidence that the copper and nickel'content of the surveillance weld differs from the vessel weld, i.e., differs from the average for the weld wire heat number associated with the vessel weld and the surveillance weld, the ratio procedure must be used.
Qeefjii.~ PTS/PT LimitEvaluation 3.
Ifthe limiting material for your plant changes or ifthe adjusted reference temperature for
- the limiting material increases as a result. of the above evaluations, provide. the revised RT~~ value for the limiting material in accordance with 10 CFR 50.61.
In addition, ifthe adjusted RT>> value increased, provide a schedule for revising the PT and LTOP limits.
The schedule should ensure that compliance with 10 CFR Part 50 Appendix G is maintained.
Qyf~rgge 1.
Memorandum from Keith R. Wichman to Edmund J. Sullivan, "Meeting Summary for November 12, 1997 Meeting with Owners Group Representatives and NEI Regarding Review of Responses to Generic Letter 92-01, Revision, Supplement 1 Responses,"
dated November 19, 1997.
Attachments:
- 1. Table1
- 2. Tables2,3
TABLE 1 Facility:
Vessel Manufacturer:
Information requested on RPV Weld and/or Limiting Materials RPV Best-,
Weld Wire Estimate Heat <'>
Copper Best-Estimate Nickel EOL ID F.luence (x 10'9)
Assigned Material Chemistry Factor (CF)
Method of Determining CF(~)
Initial RT~~
(R 4otw)
Margin ART or RT~s at EOL (1) or the material identification of the limiting material as requested in Section 1.0 (1.)
(2) determined from tables or from surveillance data D cus on f he n
I is IVI th W~IUN Data sed for Each W Id Wire Hea
~i~ii~
Attachment 1
l
Table 2: Heat xxxx Capsule ID (including source)
Cu Ni Irradiation Temperature
('F)
Fluence (x10i ~
Measured hRT~g
('F)
Data Used in Assessing Vessel (Yor N)
Table 3: Heat xxxx Capsule ID (including source)
Cu Ni Irradiation Temperature
('F)
Fluence Factor Measured BRT~r
('F)
Adjusted
~RTNor
('F)
Predicted BRTNor
('F)
(Adjusted-Predicted) hRT~,
('F)
I