RS-07-030, Supplement to Response to Request for Additional Information Regarding Application for Steam Generator Tube Integrity Technical Specification
| ML070871117 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 02/23/2007 |
| From: | Benyak D Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-07-030 | |
| Download: ML070871117 (37) | |
Text
Exelon Generat ion www.exeloncorp.com Exelkn.
4300 Wnfid RoadNucear Warrenville. IL 60555 10 CFR 50.90 RS-07-030 February 23, 2007 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. 50-456 and 50-457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. 50-454 and 50-455
Subject:
Supplement to Response to Request for Additional Information Regarding Application for Steam Generator Tube Integrity Technical Specification
References:
(1) Letter from J. A. Bauer (Exelon Generation Company, LLC) to U. S.
NRC, "Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity," dated November 18, 2005 (2) Letter from S. J. Campbell (U. S. NRC) to C. M. Crane (Exelon Generation Company, LLC), "Byron Station, Unit Nos. 1 and 2, and Braidwood Station, Unit Nos. 1 and 2 - Request for Additional Information Related to Technical Specification Improvement Regarding Steam Generator Tube Integrity," dated August 4, 2006 (3) Letter from D. M. Benyak (Exelon Generation Company, LLC) to U. S. NRC, "Response to Request for Additional Information Regarding Application for Steam Generator Tube Integrity Technical Specification," dated August 18, 2006 (4) Letter from R. F. Kuntz (U. S. NRC) to C. M. Crane (Exelon Generation Company, LLC), "Byron Station Unit Nos. 1 and 2 and Braidwood Station, Unit Nos. 1 and 2 - Request for Additional Information Related to Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity," dated December 13, 2006
February 23, 2007 U.S. Nuclear Regulatory Commission Page 2 (5) Letter from D. M. Benyak (Exelon Generation Company, LLC), to U.
S. NRC, "Response to Request for Additional Information Regarding Application for Steam Generator Tube Integrity Technical Specification," dated February 15, 2007 The purpose of this submittal is to provide a supplement to the information presented in Reference 5. This additional information is required by the NRC to complete their review of the Reference 1 application.
In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Appendix A Technical Specifications (TS), of Facility Operating License Nos. NPF-72, NPF-77, NPF-37, and NPF-66 for Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2, respectively. The proposed changes were to revise the TS requirements related to steam generator tube integrity. The change was consistent with NRC approved Revision 4 to Technical Specification Task Force (TSTF) Standard Technical Specification Change Traveler, TSTF-449, "Steam Generator Tube Integrity."
In the course of their review the NRC determined that additional information was required. This request was provided in Reference 2. The response to this initial request for additional information (RAI) was provided in the Reference 3 submittal. Reference 4 requested additional information specific to the Braidwood Station Unit 2 and Byron Station Unit 2 alternate repair criteria analyses. The response to this request was provided in the Reference 5 submittal.
The responses to the remaining four questions are contained in the Attachments to this letter. These responses were prepared by the Westinghouse Electric Company, LLC (Westinghouse) and subsequently reviewed and approved by EGC. During the validation review, it was identified that an essential clarifying word was left out of the discussion in the EGC combined response to NRC Questions 3 and 4. The necessary clarification of this portion of the discussion is being provided here.
In both the proprietary and non-proprietary versions of Westinghouse letter LTR-CDME-07-31, "Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units 1 and 2," provided in the attachments, the text of the paragraph, starting at the bottom of page 4 of both versions, omits the word "differential" in two places. The changes to the paragraph are highlighted in bold type font in the text below. The text should read as shown.
February 23, 2007 U.S. Nuclear Regulatory Commission Page 3 Based on a review of Tables 7-7 through 7-14, considering the new crevice pressuredata and analyses and a dividerplate which is assumed to be non-functional, the bounding condition for the determinationof the H* length remains the SLB performance criteria. The minimum contact length increasesfrom 8.61 inches in Zone C reportedin LTR CDME-05-32-P, Rev. 2 to 11.50 inches in Zone C. The reduced crevice pressuredifferential significantlyreduces the driving head on any leaked fluid. Therefore, the relationshipthat determines the depth into the tubesheet to meet the requiredlimitation of twice normal operating primary-to-secondaryleak rate during a postulated SLB is not affected. In fact, the depth necessary to meet the leak rate requirements will decrease despite the reducedcontact pressurebetween the tube and the tubesheet. The net effect of the reducedcrevice pressure differential is to reduce the requireddepth into the tubesheet to maintain the bellwetherprinciple.
The attached request for additional information is subdivided as shown below.
Attachment 1 provides Westinghouse Electric Company, LLC (Westinghouse) document LTR-CDME-07-31 P-Attachment, "Response to Draft NRC Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units 1 and 2" (Proprietary).
Attachment 2 provides affidavit CAW-07-2244, signed by Westinghouse, the owner of the proprietary information for withholding the information provided in Attachment 1.
Attachment 3 provides Westinghouse document LTR-CDME-07-31 NP-Attachment, "Response to Draft NRC Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units land 2" (Non-Proprietary). contains information proprietary to Westinghouse and it is supported by an affidavit signed by Westinghouse, the owner of the information. The affidavits provided in Attachment 2 sets forth the basis on which the information may be withheld from public disclosure by the NRC and addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390, "Public inspections, exemptions, requests for withholding." Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance with 10 CFR 2.390.
Correspondence with respect to the copyright or proprietary aspects of the items listed above or the supporting Westinghouse affidavit should reference CAW-07-2244 and should be addressed to J. A. Gresham, Manager, Regulatory Compliance and Plant Licensing, Westinghouse Electric Company LLC, P.O. Box 355, Pittsburgh, Pennsylvania 15230-0355.
February 23, 2007 U.S. Nuclear Regulatory Commission Page 4 The information provided in this letter supplements the supporting analysis for the original license amendment request as described in Reference 1. The conclusions of the No Significant Hazards Consideration and the Environmental Consideration provided in of the Reference 1 letter are not affected by this additional information.
In accordance with 10 CFR 50.91(b), "State consultation," EGC is providing the State of Illinois with a copy of this letter and its attachments to the designated State Official.
EGC requests that this proposed license amendment change be approved by April 2, 2007, to support the inspection activities for Byron Unit 2, Refueling Outage 13.
If you have any questions about this letter, please contact Mr. David Chrzanowski at (630) 657-2816.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 2 3 th day of February 2007.
Respectfully, 1Y7AAA1 Darin Benyak Manager - Licensing
Attachment 1 Westinghouse Electric Company, LLC LTR-CDME-07-31 P-Attachment Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units 1 and 2 (Proprietary)
Attachment 2 Westinghouse Electric Company, LLC Affidavit CAW-07-2244 Request to Withhold Proprietary Information Contained In LTR-CDME-07-31 P-Attachment
Westinghouse Westinghouse Electric Company Nuclear Services P.O. Box 355 Pittsburgh. Pennsylvania 15230-0355 USA U.S. Nuclear Regulatory Commission Directtel: (412) 374-4643 Document Control Desk Direct fax: (412) 374-4011 Washington, DC 20555-0001 e-maik greshaja@westinghouse.com Our ref. CAW-07-2244 February 15, 2007 APPLICATION FOR WITHHOLDING PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE
Subject:
LTR-CDME-07-31 P-Attachment, "Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units I and 2 (TAC NOS.
MC8966, MC8967, MC8968, and MC8969)," dated February 14, 2007 (Proprietary)
The proprietary information for which withholding is being requested in the above-referenced report is further identified in Affidavit CAW-07-2244 signed by the owner of the proprietary information, Westinghouse Electric Company LLC. The affidavit, which accompanies this letter, sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR Section 2.390 of the Commission's regulations.
Accordingly, this letter authorizes the utilization of the accompanying affidavit by Exelon Generation Company, LLC.
Correspondence with respect to the proprietary aspects of the application for withholding or the Westinghouse affidavit should reference this letter, CAW-07-2244, and should be addressed to J. A. Gresham, Manager, Regulatory Compliance and Plant Licensing, Westinghouse Electric Company LLC, P.O. Box 355, Pittsburgh, Pennsylvania 15230-0355.
Very truly yours, A. Gresham, Manager Regulatory Compliance and Plant Licensing Enclosures cc: Jon Thompson (NRC O-7E IA)
CAW-07-2244 bcc: J. A. Gresham (ECE 4-7A) IL R. Bastien, IL (Nivelles, Belgium)
C. Brinkman, I L (Westinghouse Electric Co., 12300 Twinbrook Parkway, Suite 330, Rockville, MD 20852)
RCPL Administrative Aide (ECE 4-7A) IL (lctier and affidavit only)
G. W. Whiteman, Waltz Mill H. 0. Lagally, Waltz Mill C. D. Cassino, Waltz Mill N. R. Brown, Waltz Mill J. P. Molkenthin, Windsor
CAW-07-2244 AFFIDAVIT COMMONWEALTH OF PENNSYLVANIA:
ss COUNTY OF ALLEGHENY:
Before me, the undersigned authority, personally appeared J. A. Gresham, who, being by me duly sworn according to law, deposes and says that he is authorized to execute this Affidavit on behalf of Westinghouse Electric Company LLC (Westinghouse), and that the averments of fact set forth in this Affidavit are true and correct to the best of his knowledge, information, and belief:
'J. A. Gresham, Manager Regulatory Compliance and Plant Licensing Sworn to and subscribed before me this 15t day of February, 2007 Notary Public COMMONWEALTH OF PENNSYLVANIA Notarial sea Sharon L Marlke, Nokary Pubflc Monroeviffe Boro, Alnecheny County My Commission Expires Jan. 29,2011 fiembF.!. Dnn,",w h,:anklA~ociation of Notaries
2 CAW-07-2244 (1) 1am Manager, Regulatory Compliance and Plant Licensing, in Nuclear Services, Westinghouse Electric Company LLC (Westinghouse), and as such, I have been specifically delegated the function of reviewing the proprietary information sought to be withheld from public disclosure in connection with nuclear power plant licensing and rule making proceedings, and am authorized to apply for its withholding on behalf of Westinghouse.
(2) 1am making this Affidavit in conformance with the provisions of 10 CFR Section 2.390 of the Commission's regulations and in conjunction with the Westinghouse "Application for Withholding" accompanying this Affidavit.
(3) 1 have personal knowledge of the criteria and procedures utilized by Westinghouse in designating information as a trade secret, privileged or as confidential commercial or financial information.
(4) Pursuant to the provisions of paragraph (b)(4) of Section 2.390 of the Commission's regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld.
(i) The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse.
(ii) The information is of a type customarily held in confidence by Westinghouse and not customarily disclosed to the public. Westinghouse has a rational basis for determining the types of information customarily held in confidence by it and, in that connection, utilizes a system to determine when and whether to hold certain types of information in confidence. The application of that system and the substance of that system constitutes Westinghouse policy and provides the rational basis required.
Under that system, information is held in confidence if it falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:
(a) The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.
3 CAW-07-2244 (b) It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage, e.g., by optimization or improved marketability.
(c) Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.
(d) It reveals cost or price information, production capacities, budget levels, or commercial strategies of Westinghouse, its customers or suppliers.
(e) It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs ofpotential commercial value to Westinghouse.
(f) It contains patentable ideas, for which patent protection may be desirable.
There are sound policy reasons behind the Westinghouse system which include the following:
(a) The use of such information by Westinghouse gives Westinghouse a competitive advantage over its competitors. It is, therefore, withheld from disclosure to protect the Westinghouse competitive position.
(b) It is information that is marketable in many ways. The extent to which such information is available to competitors diminishes the Westinghouse ability to sell products and services involving the use of the information.
(c) Use by our competitor would put Westinghouse at a competitive disadvantage by reducing his expenditure of resources at our expense.
(d) Each component of proprietary information pertinent to a particular competitive advantage is potentially as valuable as the total competitive advantage. If competitors acquire components of proprietary information, any one component
4 CAW-07-2244 may be the key to the entire puzzle, thercby dcpriving Westinghouse of a competitive advantage.
(e) Unrestricted disclosure would jeopardize the position of prominence of Westinghouse in the world market, and thereby give a market advantage to the competition of those countries.
(f) The Westinghouse capacity to invest corporate assets in research and development depends upon the success in obtaining and maintaining a competitive advantage.
(iii) The information is being transmitted to the Commission in confidence and, under the provisions of 10 CFR Section 2.390, it is to be received in confidence by the Commission.
(iv) The information sought to be protected is not available in public sources or available information has not been previously employed in the same original manner or method to the best of our knowledge and belief.
(v) The proprietary information sought to be wvithheld in this submittal is that which is appropriately marked in LTR-CDME-07-31 P-Attachment, "Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units I and 2 (TAC NOS. MC8966, MC8967, MC8968, and MC8969)," dated February 14, 2007 (Proprietary), for submittal to the Commission, being transmitted by Exelon Generation Company, LLC Application for Withholding Proprietary Information from Public Disclosure to the Document Control Desk. The proprietary information as submitted for use by Westinghouse for Byron Unit 2 and Braidwood Unit 2 is expected to be applicable to other licensee submittals in support of implementing a limited inspection of the tube joint within the tubeshect region of the steam generators and is provided in response to a NRC request for additional information on LTR-CDME-05-32-P, Rev. 2, "Limited Inspection of the Steam Generator Tube Portion Within the Tubeshect at Byron 2 and Braidwood 2," dated August 2005.
This information is part of that which will enable Westinghouse to:
5 CAW-07-2244 (a) Provide documentation of the analyses, methods, and testing for the implementation of an alternate repair criteria for the portion if the tubes within the tubesheet of the Byron Unit 2 and Braidwood Unit 2 steam generators.
(b) Assist the customers in the licensing and NRC approval of the Technical Specification changes associated with the alternate repair criteria.
Further this information has substantial commercial value as follows:
(a) Westinghouse plans to sell the use ofsimilar information to its customers for the purposes of meeting NRC requirements for licensing documentation.
(b) Westinghouse can sell support and defcnse of the technology to its customers in the licensing process.
Public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar calculation, evaluation and licensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.
The development of the technology described in part by the information is the result of applying the results of many years of experience in an intensive Westinghouse effort and the expenditure of a considerable sum of money.
In order for competitors of Westinghouse to duplicate this information, similar technical programs would have to be performed and a significant manpower effort, having the requisite talent and experience, would have to be expended.
Further the deponent sayeth not.
PROPRIETARY INFORMATION NOTICE Transmitted herewith are proprietary andlor non-proprietary versions of documents furnished to the NRC in connection with requests for generic and/or plant-specific review and approval.
In order to conform to the requirements of 10 CFR 2.390 of the Commission's regulations concerning the protection of proprietary information so submitted to the NRC, the information which is proprietary in the proprietary versions is contained within brackets, and where the proprietary information has been deleted in the non-proprietary versions, only the brackets remain (the information that was contained within the brackets in the proprietary versions having been deleted). Thejustification for claiming the information so designated as proprietary is indicated in both versions by means of lower case letters (a) through (f) located as a superscript immediately following the brackets enclosing each item of information being identified as proprietary or in the margin opposite such information. These lower case letters refer to the types of informationi Westinghouse customarily holds in confidence identified in Sections (4)(ii)(a) through (4)(ii)(f) of the affidavit accompanying this transmittal pursuant to 10 CFR 2.390(b)(I).
COPYRIGHT NOTICE The reports transmitted herewith each bear a Westinghouse copyright notice. The NRC is permitted to make the number of copies of the information contained in these reports which are necessary for its internal use in connection with generic and plant-specific reviews and approvals as well as the issuance, denial, amendment, transfer, renewal, modification, suspension, revocation, or violation of a license, permit, order, or regulation subject to the requirements of 10 CFR 2.390 regarding restrictions on public disclosure to the extent such information has been identified as proprietary by Westinghouse, copyright protection notwithstanding. With respect to the non-proprietary versions of these reports, the NRC is permitted to make the number of copies beyond those necessary for its internal use which are necessary in order to have one copy available for public viewing in the appropriate docket files in the public document room in Washington, DC and in local public document rooms as may be required by NRC regulations if the number of copies submitted is insufficient for this purpose. Copies made by the NRC must include the copyright notice in all instances and the proprietary notice if the original was identified as proprietary.
Attachment 3 Westinghouse Electric Company, LLC LTR-CDME-07-31 NP-Attachment Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units 1 and 2 (Non-Proprietary)
WESTINGHOUSE NON-PROPRIETARY CLASS 3 LTR-CDME-07-31 NP-Attachment Exelon Generation Company, LLC Response to NRC Draft Request for Additional Information Related to the Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity for Byron Units 1 and 2 and Braidwood Units 1 and 2 (TAC NOS. MC8966, MC8967, MC8968, AND MC8969)
February 14, 2007 Westinghouse Electric Company LLC
. P.O. Box 158 Madison, PA 15663 02007 Westinghouse Electric Company LLC All Rights Reserved LTR-CDME-07-3 1 NP-Attachment
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Response to Draft Request for Additional Information Regarding Application for Steam Generator Tube Integrity Technical Specification NRC Question 1:
Please comment on ANL's observation regarding the possibility of an incorrect choice of thermal expansion coefficient for the tubesheet collar specimens used in the Westinghouse tests in terms of how it may apply to Byron 2 and Braidwood Unit 2. If you disagree with the ANL observations pertaining to Callaway or if you believe the ANL observations not to be relevant to Byron Unit 2 and Braidwood Unit 2, explain why.
NRC Question 2:
If there is a problem with the assumed 'alues of thermal expansion coefficient, please characterize the problem and provide any necessary corrections to Westinghouse report LTR-CDME-05-32-P. (Of priority interest to the staff, to support timely completion of the staff's review, are any revisions needed to Tables 7-7 through 7-14, Figures 7-4 through 7-8, and Figures 8-1 through 8-5.)
Exelon Generation Company, LLC (EGC) response to Questions I and 2:
It is the opinion of Westinghouse (Reference 1) that the choice of the thermal expansion coefficients (TEC) cited in LTR-CDME-05-32-P, Rev. 2 is correct. This opinion is based on the ASTM definition of A1018/A108 specifications for cold finished, steel bar stock (Reference 2) that cite a maximum carbon range of 0.28% or less for the type ofAl018 steel used to manufacture the test specimen collars. A value of 0.28% or less carbon content in steel is in the range for plain carbon, low alloy and carbon manganese'steels in Material Group A of the 1995 ASME B&PV Code,Section II Part D (Reference 3). The TEC values listed in the 1995 Code for Materials Group A were the values used in the test specimen analysis for the residual contact pressure due to the hydraulic expansion of the tube within the simulated tube sheet collar. The TEC values for Materials Group A are also the values used for metals with the chemical composition of SA-508 Class 2 steel. It is appropriate to use the values previously cited by Westinghouse for the test specimen collars to generate the residual contact pressure data for use in the H* and B* calculations because the TEC values accurately represent the material properties ofA1018 steel. The table below lists the TEC for Materials Group A from Reference 3. It is not necessary to revise Tables 7-7 through 7-14, Figures 7-4 through 7-8, and Figures 8-1 through 8-5 to account for a reduced coefficient of thermal expansion.
LTR-CDME-07-31 NP-Attachment Page 2 of 22
WESTINGI IOUSE NON-PROPRIETARY CLASS 3 Table 1: Thermal Expansion Coefficient Values for A1018 and SA-508 Class 2 Steel Thermal Expansion Coefficient Temperature Plain Carbon Steel SA-508 Class 2 70 OF 6.50 6.50 400 OF 7.07 7.07 600 OF 7.42 7.42 TEC in units of 10"6 in/in/OF LTR-CDME-07-3 i NP-Attachment Page 3 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 NRC Question 3:
Provide any revisions or corrections to LTR-CDME-05-32-P to reflect any new crevice pressure test data and analyses relevant to H* and B* applications at Byron 2 and Braidwood. (Of priority interest to the staff, to support timely completion of the staff's review, are any needed revisions to Tables 7-7 through 7-14, Figures 7-4 through 7-18, and Figures 8-1 through 8-5. The staff needs this information to ensure that the qualitative arguments cited in its previous safety evaluations (i.e., the one time amendments for a 17-inch inspection zone at Byron and Braidwood 2) remain valid. These arguments concerned the relative length of tubing in the 17-inch inspection zone that experiences an increase in contact pressure versus the length that experiences a decrease in contact pressure.)
NRC Question 4:
Provide alternative versions of Tables 7-7 through 7-14, Figures 7-4 through 7-8, and Figures 8-1 through 8-5 to reflect a divider plate which is assumed to be equally non-functional. The staff needs this information to ensure that the qualitative arguments cited it its previous safety evaluations (i.e., the one-time amendments for a 17-inch inspection zone at Byron and Braidwood
- 2) remain valid. These arguments concerned the relative length of tubing in the 17-inch inspection zone that experience an increase in contact pressure versus the length that experience a decease in contact pressure. Alternatively, discuss your plans for revising the propose amendment to include provisions for periodic inspection and repair (if needed) of the divider plate and divider plate welds.
Exelon Generation Company, LLC (EGC) response to Questions 3 and 4:
Tables 7-7 through 7-14, Figures 7-4 through 7-8, and Figures 8-1 through 8-5 of LTR-CDME-05-32-P have been revised to reflect the new crevice pressure data and analyses and to reflect a divider plate which is assumed to be non-functional and are provided below (Reference 4). Note that in this context the term "non-functional" refers only to the ability of the divider plate to restrict vertical displacements of the tubesheet. An updated and refined finite element analysis was used to check the assumptions and results related to the divider plate. The results of additional changes have been factored into the tables and figures to account for changes in current methodology from that utilized in LTR-CDME-05-32-P. These additional changes are:
- The SLB factor of safety has changed from 1.43 to 1.4 (Per NEI 97-06, Rev. 2)
- An uncertainty for the location of the bottom of the expansion transition (BET) of 0.3 inches has been added to all H* distances for each radial location.
" Crevice pressure ratios of 0.3686 and 0.6977 were used for the steam line break and normal operating conditions, respectively.
- A divider plate factor of 1.00 is used to eliminate any restraint of the vertical tubesheet displacements.
Based on a review of Tables 7-7 through 7-14, considering the new crevice pressure data and analyses and a divider plate which is assumed to be non-functional, the bounding condition for the determination of the H* length remains the SLB performance criteria. The minimum contact LTR-CDME-07-31 NP-Attachment Page 4 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 length increases from 8.61 inches in Zone C reported in LTR-CDME-05-32-P, Rev. 2 to 11.50 inches in Zone C. The reduced crevice pressure significantly reduces the driving head on any leaked fluid. Therefore, the relationship that determines the depth into the tubesheet to meet the required limitation of twice normal operating primary-to-secondary leak rate during a postulated SLB is not affected. In fact, the depth necessary to meet the leak rate requirements will decrease despite the reduced contact pressure between the tube and the tubesheet. The net effect of the reduced crevice pressure is to reduce the required depth into the tubesheet to maintain the bellwether principle.
Referring to revised Figures 7-4 through 7-8 and Figures 8-1 through 8-5, a comparison of the curves at the various elevations leads to the conclusion for at least a length of 6.5 inches above the elevation of 4.13 inches above the bottom of the tubeshect there is an increase in the contact pressure in going from normal operating to a postulated SLB condition at all radial locations (See Figures 8-1 and 8-2). Hence, it is reasonable to omit any consideration of the inspection of bulges or other artifacts below a depth of 17 inches from the top of the tubesheet. The trend is consistent, at radii (near the periphery) where the contact pressure decreases or the increase is not as great near the bottom of the tubesheet, the increase in contact pressure at 10.5 inches above the bottom of the tubesheet is significant. Therefore, applying'a very conservative inspection sampling length of 17 inches downward from the top of the tubesheet during the Byron Unit 2 and Braidwood Unit 2 outages provides a high level of confidence that the potential leak rate from indications below 17 inches from the top of the tubesheet during a postulated SLB will be bounded by twice the normal operating primary-to-secondary leak rate.
LTR-CDME-07-31 NP-Attachment Page 5 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-7. Cumulative Forces Resisting Pull Out from the Top of the Tubesheet Byron/Braidwood 2 - Hot Leg Normal Conditions Low Ta.r, High T,,,. DP Factor = 1.00 2.c,e LTR-CDME-07-31 NP-Attachment Page 6 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-8. Cumulative Forces Resisting Pull Out from the TTS Byron/Braidwood 2 - Hot Leg Normal Conditions High Ta.., Low TCc, DP Factor = 1.00 a,c.e LTR-CDME-07-31 NP-Attachment Page 7 of 22
WESTINGIIOUSE NON-PROPRIETARY CLASS 3 Table 7-9. Cumulative Forces Resisting Pull Out from the TTS Byron/Braidwood 2-Faulted (SLB) Conditions, DP Factor = 1.00 ac.e LTR-CDME-07-31 NP-Attachment Page 8 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-10. Cumulative Forces Resisting Pull Out from the TTS Byron/Braidwood 2 FLB Conditions Low T,,,, High T,. DP Factor= 1.00 a.ce LTR-CDME-07-31 NP-Attachment Page 9 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-11. Cumulative Forces Resisting Pull Out for FLB Conditions High T.,, Low T,,, DP Factor = 1.00 acle LTR-CDME-07-31 NP-Attachment Page 10 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-12. Large Displacement, 0.25 in. Pullout Test Data a,c,e Table 7-13. Summary of H*. Calculations for Byron/Braidwood Unit 2 axc.e LTR-CDME-07-31 NP-Attachment Page II of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-14. 11* Summary Table Engagement from Zone Limiting Loading Condition TTS (inches)
A 1.4 SLB P 6.22 B 1.4 SLB P 10.87 C 1.4SLB P 11.50 LTR-CDME-07-31 NP-Attachment Page 12 of 22
WESTINGHlOUSE NON-PROPRIETARY CLASS 3 ac.e Figure 7-3. Contact Pressures for Normal Condition (Tm.n) at Byron/Braidwood 2 DP Factor = 1.00 a,ce Figure 74. Contact Pressures for Normal Condition (Tin,,) at Byron and Braidwood Unit 2 DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 13 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 a c,e Figure 7-5. Contact Pressures for SLB Faulted Condition at Byron and Braidwood 2 DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 14 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 ac,e Figure 7-6. Contact Pressures for FLB Faulted Condition at Byron and Braidwood 2 (Tmin), DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 15 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 a.,c,e Figure 7-7. Contact Pressures for FLB Faulted Condition at Byron and Braidwood 2 (Tmax), DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 16 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 8-1. Change in Contact Pressure at 10.5 Inches Below the TTS, DP Factor 1.00 LTR-CDME-07-31 NP-Attachment Page 17 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 a,c,e Figure 8-2. Change in Contact Pressure at 12.6 Inches Below the TTS, DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 18 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 a,c,e Figure 8-3. Change in Contact Pressure at 16.9 Inches Below the TTS, DP Factor = 1.00 LTR-CDME-07-3 I NP-Attachment Page 19 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 8-4. Change in Contact Pressure at the Bottom of the Tubesheet, DP Factor = 1.00 LTR-CDME-07-31 NP-Attachment Page 20 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 ac,e 7
Figure 8-5. Change in Contact Pressure at 8.25 Inches Below the TTS, DP Factor = 1.00 LTR-CDME-07-3 1NP-Attachment Page 21 of 22
WESTINGHOUSE NON-PROPRIETARY CLASS 3 Refercnces
- 1. STD-MCE-07-7, "Thermal Expansion of Steels," R.E. Gold, February 2007.
- 2. ASTM A108-03, "Standard Specification for Steel Bar, Carbon and Alloy, Cold-Finished," ASTM International, © 2003.
- 3. 1995 ASME Boiler and Pressure Vessel Code, Section 11, Part D, Properties.
- 4. LTR-CDME-07-28, "Identification of Byron 2 and Braidwood 2 Microsoft Excel Spreadsheets Supporting LTR-CDME-07-31 P-Attachment," C.D. Cassino, February 2007.
LTR-CDME-07-31 NP-Attachment Page 22 of 22