ML13094A080
ML13094A080 | |
Person / Time | |
---|---|
Site: | San Onofre ![]() |
Issue date: | 04/02/2013 |
From: | St.Onge R Southern California Edison Co |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
TAC ME9727, CAW-13-3662 | |
Download: ML13094A080 (31) | |
Text
SOUTHERN CALIFORNIA Richard J. St. Onge Proprietary Information Director, Nuclear Regulatory Affairs and EDISON Withhold from Public Disclosure Emergency Planning An EDISON INTERNAI7IONAL-1 Comnpany~
April 2, 2013 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Docket No. 50-361 Response to Request for Additional Information (RAI 13), Revision I Regarding Confirmatory Action Letter Response (TAC No. ME 9727)
San Onofre Nuclear Generating Station, Unit 2
References:
- 1. Letter from Mr. Elmo E. Collins (USNRC) to Mr. Peter T. Dietrich (SCE), dated March 27, 2012, Confirmatory Action Letter 4-12-001, San Onofre Nuclear Generating Station, Units 2 and 3, Commitments to Address Steam Generator Tube Degradation
- 2. Letter from Mr. Peter T. Dietrich (SCE) to Mr. Elmo E. Collins (USNRC), dated October 3, 2012, Confirmatory Action Letter - Actions to Address Steam Generator Tube Degradation, San Onofre Nuclear Generating Station, Unit 2
- 3. Letter from Mr. James R. Hall (USNRC) to Mr. Peter T. Dietrich (SCE), dated December 26, 2012, Request for Additional Information Regarding Response to Confirmatory Action Letter, San Onofre Nuclear Generating Station, Unit 2
- 4. Letter from Mr. Richard J. St. Onge (SCE) to Document Control Desk (USNRC), dated January 18, 2013, Response to Request for Additional Information (RAI 13) Regarding Confirmatory Action Letter Response, San Onofre Nuclear Generating Station, Unit 2
Dear Sir or Madam,
On March 27, 2012, the Nuclear Regulatory Commission (NRC) issued a Confirmatory Action Letter (CAL) (Reference 1) to Southern California Edison (SCE) describing actions that the NRC and SCE agreed would be completed to address issues identified in the steam generator tubes of San Onofre Nuclear Generating Station (SONGS) Units 2 and 3. In a letter to the NRC dated October 3, 2012 (Reference 2), SCE reported completion of the Unit 2 CAL actions and included a Return to Service Report (RTSR) that provided details of their completion.
By letter dated December 26, 2012 (Reference 3), the NRC issued Requests for Additional Information (RAIs) regarding the CAL response. SCE provided a response to RAI 13 in a letter dated January 18, 2013 (Reference 4). The response to RAI 13 was revised to address questions raised by the NRC during the public meeting on February 27, 2013. Enclosure 2 of this submittal provides Revision 1 of the RAI 13 response.
P.O. Box 128 Proprietary Information San Clemente, CA 92672 Withhold from Public Disclosure Decontrolled Upon Removal From Enclosure 2
Proprietary Information Withhold from Public Disclosure Document Control Desk April 2, 2013 of this submittal contains proprietary information. SCE requests that this proprietary enclosure be withheld from public disclosure in accordance with 10 CFR 2.390(a)(4). provides notarized affidavits from Westinghouse and Mitsubishi Heavy Industries (MHI), which set forth the basis on which the information in Enclosure 2 may be withheld from public disclosure by the NRC and addresses with specificity the considerations listed by paragraph (b)(4) of 10 CFR 2.390. Proprietary information in Enclosure 2 was extracted from Westinghouse document LTR-LAM-1 3-23-P-Attachment, "Follow-on Response to NRC Confirmatory Action Letter RAI #13 for SONGS Unit 2" (Proprietary), which is addressed in the Westinghouse affidavit. Enclosure 3 provides the non-proprietary version of Enclosure 2.
There are no new regulatory commitments contained in this letter. If you have any questions or require additional information, please call me at (949) 368-6240.
Sincerely,
Enclosure:
- 1. Notarized Affidavits
- 2. Response to RAI 13, Revision 1 (Proprietary)
- 3. Response to RAI 13, Revision 1 (Non-Proprietary) cc: A. T. Howell Ill, Regional Administrator, NRC Region IV J. R. Hall, NRC Project Manager, SONGS Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, SONGS Units 2 and 3 R. E. Lantz, Branch Chief, Division of Reactor Projects, NRC Region IV Proprietary Information Withhold from Public Disclosure Decontrolled Upon Removal From Enclosure 2
ENCLOSURE 1 Notarized Affidavits
Westinghouse Westinghouse Electric Company Nuclear Services 1000 Westinghouse Drive Cranberry Township, Pennsylvania 16066 USA U.S. Nuclear Regulatory Commission Direct tel: (412) 374-4643 Document Control Desk Direct fax: (724) 720-0754 11555 Rockville Pike e-mail: greshaja@westinghouse.com Rockville, MD 20852 Proj letter:
CAW-13-3662 March 15, 2013 APPLICATION FOR WITHHOLDING PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE
Subject:
LTR-LAM-13-23-P-Attachment, "Follow-on Response to NRC Confirmatory Action Letter RAI #13 for SONGS Unit 2" (Proprietary)
The proprietary information for which withholding is being requested in the above-referenced report is further identified in Affidavit CAW-13-3662 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 Southern California Edison.
Correspondence with respect to the proprietary aspects of the application for withholding or the Westinghouse affidavit should reference CAW-13-3662, and should be addressed to James A. Gresham, Manager, Regulatory Compliance, Westinghouse Electric Company, Suite 428, 1000 Westinghouse Drive, Cranberry Township, Pennsylvania 16066.
Very truly yours,
/('rJames A. Gresham, Manager Regulatory Compliance Enclosures
CAW-13-3662 AFFIDAVIT COMMONWEALTH OF PENNSYLVANIA:
ss COUNTY OF BUTLER:
Before me, the undersigned authority, personally appeared James 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:
IJames A. Gresham, Manager Regulatory Compliance Sworn to and subscribed before me this 15th day of March 2013 A40 C4- ,1 Notary Public /
COMMONWEALTH OF PENNSYLVANIA Notailal Seal Anne M.Stegman, Nota[Y Public I unity Twp., Westmoreland County My Commio Expires Aug. 7,2016 I MEaBER. PENNSYLVANIA A TION OFNOTARIES
2 CAW-13-3662 (1) 1 am Manager, Regulatory Compliance, 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) I am 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 Withhol~ding Proprietary Information from Public Disclosure accompanying this Affidavit.
(3) I 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
3 CAW- 13-3662 Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.
(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 of potential 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.
4 CAW- 13-3662 (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 may be the key to the entire puzzle, thereby depriving 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 2.3 90, 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 withheld in this submittal is that which is appropriately marked in LTR-LAM-13-23-P-Attachment, "Follow-on Response to NRC Confirmatory Action Letter RAI # 13 for SONGS Unit 2" (Proprietary), dated March 15, 2013 for submittal to the Commission, being transmitted by Southern California Edison letter and Application for Withholding Proprietary Information from Public Disclosure, to the Document Control Desk. The proprietary information as submitted by Westinghouse is that associated with a response to NRC RAI #13 and may be used only for that purpose.
This document also contains appropriately marked third party proprietary information from MHI, used with permission. The scope of this affidavit does not include withholding this information and must be addressed separately by MHI.
5 CAW-13-3662 This information is part of that which will enable Westinghouse to:
(a) Adequately support the response to the NRC RAI.
Further this information has substantial commercial value as follows:
(a) Westinghouse plans to sell the use of the information to its customers for the purpose of supporting responses to NRC RAls.
(b) Westinghouse can sell support and defense of safety analysis services.
(c) The information requested to be withheld reveals the distinguishing aspects of a methodology which was developed by Westinghouse.
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 technical evaluation justifications 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 tile 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 and/or 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). The justification 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 information 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)(1).
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.
MITSUBISHI HEAVY INDUSTRIES, LTD.
AFFIDAVIT I, Jinichi Miyaguchi, state as follows:
- 1. I am Director, Nuclear Plant Component Designing Department, of Mitsubishi Heavy Industries, Ltd. ("MHI"), and have been delegated the function of reviewing the referenced documentation to determine whether it contains MHI's information that should be withheld from public disclosure pursuant to 10 C.F.R. § 2.390 (a)(4) as trade secrets and commercial or financial information that is privileged or confidential.
- 2. In accordance with my responsibilities, I have reviewed the following documentation and have determined that it contains MHI proprietary information that should be withheld from public disclosure. Those pages containing proprietary information have been bracketed with an open and closed bracket as shown here "[ I" / and should be withheld from public disclosure pursuant to 10 C.F.R. § 2.390 (a)(4).
SCE's document
- Responses to the Request for Additional Information issued by NRC, regarding response to March 27, 2012 Confirmatory Action Letter for San Onofre Nuclear Generating Station Unit 2 (TAC NO.ME9727)
(RAI No. ; #13)
- 3. The information identified as proprietary in the document have in the past been, and will continue to be, held in confidence by MHI and its disclosure outside the company is limited to regulatory bodies, customers and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and is always subject to suitable measures to protect it from unauthorized use or disclosure.
- 4. The basis for holding the referenced information confidential is that they describe unique design, manufacturing, experimental and investigative information developed by MHI and not used in the exact form by any of MHI's competitors. This information was developed at significant cost to MHI, since it is the result of an intensive MHI effort.
- 5. The referenced information was furnished to the Nuclear Regulatory Commission
("NRC") in confidence and solely for the purpose of information to the NRC staff.
- 6. The referenced information is not available in public sources and could not be gathered readily from other publicly available information. Other than through the provisions in paragraph 3 above, MHI knows of no way the information could be lawfully acquired by organizations or individuals outside of MHI.
- 7. Public disclosure of the referenced information would assist competitors of MHI in their design and manufacture of nuclear plant components without incurring the costs or risks associated with the design and the manufacture of the subject component. Therefore, disclosure of the information contained in the referenced document would have the following negative impacts on the competitive position of MHI in the U.S. and world nuclear markets:
A. Loss of competitive advantage due to the costs associated with development of technologies relating to the component design, manufacture and examination.
Providing public access to such information permits competitors to duplicate or mimic the methodology without incurring the associated costs.
B. Loss of competitive advantage of MHI's ability to supply replacement or new heavy components such as steam generators.
I declare under penalty of perjury that the foregoing affidavit and the matters stated therein are true and correct to the best of my knowledge, information and belief.
Executed on this 2T day of i
- Ai ,2013.
/ fl Jinichi Miyaguchi, /
Director- Nuclear Plant Component Designing Department Mitsubishi Heavy Industries, LTD Sworn to and subscribed Before me this 2 day /
of 1 i r ,2013 k, Notary Public Hý
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Registered Number 6 2 Date MAR, 2 5, 2013 NOTARIAL CERTIFICATE This is to certify that JINICHI MIYAGUCHI , Director-Nuclear Plant Component Designing Department MITSUBISHI HEAVY INDUSTRIES, LTD has affixed his signature in my very presence to the attached document. "-:
MASAHIKO KUBOTA Notary 44 Akashimachi, Chuo-Ku, Kobe, Japan Kobe District Legal Affairs Bureau (NW82)
ENCLOSURE 3 SOUTHERN CALIFORNIA EDISON RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING RESPONSE TO CONFIRMATORY ACTION LETTER DOCKET NO. 50-361 TAC NO. ME 9727 Response to RAI 13, Revision 1 (Non-Proprietary)
RAI 13
The installation of new steam generators involved changes to the steam generator heat transfer characteristics, which could affect the performance of the plant under postulated loss of coolant accident conditions. Please explain how the existing ECCS analysis accounts for these changes, and how considerable steam generator tube plugging has been addressed in the ECCS evaluation. Provide the ECCS evaluation that will apply to the planned operating cycle.
RESPONSE - Revision 1 Summary Note: Response (2) below includes information requested in RAI 14 associated with the Emergency Core Cooling System (ECCS) evaluation. RAI 14 states: "Provide a summary disposition of the U2C17 calculations relative to the planned reduced-power operation."
(1) Evaluation of Impact of Replacement Steam Generators on Emergency Core Cooling System (ECCS) Performance Analyses Replacement steam generators (RSGs) were installed in SONGS Units 2 and 3 for Cycle 16.
The Cycle 16 ECCS performance for SONGS Units 2 and 3 with the RSGs was evaluated to demonstrate conformance to the ECCS acceptance criteria for light water nuclear power reactors contained in 10 CFR 50.46. The evaluation considered the impact of the RSGs on the Analyses of Record (AORs) for Large Break Loss-of-Coolant Accident (LBLOCA), Small Break Loss-of-Coolant Accident (SBLOCA), and post-Loss-of-Coolant Accident (LOCA) Long-Term Cooling (LTC), which are based on the original steam generators (OSGs).
The impact of the RSGs on the SONGS Units 2 and 3 ECCS performance AORs was evaluated through a two-step process. First, the design data of the RSGs, including thermal hydraulic characteristics, were compared to those of the OSGs as modeled in the ECCS performance AORs. Second, differences in design data, which were identified from the comparison, were evaluated for their impact on ECCS performance. The scope of the comparison considered all design features of the steam generators (SGs) that are modeled in the ECCS performance analysis. The most significant parameters are discussed below.
(i) Rated Thermal Power The OSGs and the RSGs were evaluated at the same core power level, as there was not a power uprate associated with installation of the RSGs.
(ii) RSG Tube Plugging and RCS Volume The RSGs have more RCS volume than the OSGs. The amount of assumed tube plugging in the RSGs is less than the OSGs. These factors result in a net increase in the total reactor coolant system (RCS) volume. This is a beneficial feature since, for example, it results in more RCS inventory available to drain into the reactor vessel during a SBLOCA, thereby delaying the time that the core begins to uncover. A larger water volume increases the amount of water available to flow through the core during the blowdown period of a LBLOCA. This increases the amount of stored energy removed from the core during the blowdown period. The increase in water volume has an insignificant impact on the post-ENCLOSURE3 Page 2 of 16
LOCA LTC analysis. The maximum number of plugged tubes per SG for the RSG was assumed to be 779 tubes (8%) per SG for the RSG Cycle 16 ECCS evaluation.
(iii) RSG Heat Transfer Characteristics The maximum assumed number of plugged tubes per SG is used in conjunction with the total number of tubes per SG to establish the minimum number of unplugged tubes per SG This is used to establish SG primary side volume, tube bundle flow area, and tube bundle heat transfer area. The RSGs have more tubes (9,727 versus 9,350) than the OSGs and a smaller value for the maximum number of plugged tubes (779 versus 2,000). RSG tubes have a larger average heated length (729.56 in. versus 680.64 in.) than the OSG tubes.
These features result in larger values for the RSG for heat transfer area, tube bundle flow area, and tube bundle water volume. This is beneficial in the short and long term for SBLOCAs, which rely upon the steam generators for RCS heat removal.
The RSG tube bundle material is Inconel 690 whereas the OSG tube bundle material is Inconel 600. While the thermal conductivity of Inconel 690 is less than that of Inconel 600, the impact is not significant in the context of ECCS performance. First, the RSGs have larger heat transfer areas which compensate for the decrease of thermal conductivity.
Second, after the subcooled forced convection mode of SG heat transfer early in a LOCA transient, the primary coolant-to-wall resistance, and not the wall resistance, is the limiting resistance for SG heat transfer during a LOCA. Therefore, the difference in thermal conductivity does not have a significant impact on ECCS performance given the overall design of the RSGs relative to the OSGs and the nature of SG heat transfer during a LOCA.
Sensitivity studies have shown that the impact due to SG heat transfer area changes is insignificant for LBLOCAs. Heat transfer characteristic differences have an insignificant impact on post-LOCA LTC.
(iv) RSG Pressure Drop / Flow Resistance The RSGs have a smaller flow resistance and, consequently, a smaller pressure drop than the OSGs based on the same set of conditions and the maximum number of plugged tubes assumed by the ECCS performance analyses. A smaller total SG pressure drop is beneficial for ECCS performance.
The evaluation of the impact of the RSGs on the SONGS Units 2 and 3 ECCS performance analyses demonstrates that the RSGs have a beneficial impact on ECCS performance.
Consequently, the results and conclusions of the SONGS Units 2 and 3 ECCS performance AORs for LBLOCA, SBLOCA, and post-LOCA LTC, performed for the OSGs, are applicable to SONGS Units 2 and 3 for operation with the RSGs.
(2) ECCS performance evaluations for SONGS Unit 2 Cycle 17 An ECCS performance analysis was performed for SONGS Unit 2 Cycle 17 to demonstrate conformance to the ECCS acceptance criteria for light water nuclear power reactors. The major changes evaluated in the Unit 2 Cycle 17 ECCS performance analysis are discussed as follows.
ENCLOSURE3 Page 3 of 16
(i) Increase in TCOLD The RCS temperature at the inlet to the core, i.e., TCOLD, has increased for Unit 2 Cycle 17 to 550°F from the previous Unit 2 Cycle 16 value of 541°F ("TCOLD Restoration"). The effect of the change in TCOLD is bounded by the Unit 2 Cycle 17 ECCS performance analysis.
(ii) SG Tube Plugging The maximum number of plugged tubes per SG for Unit 2 Cycle 17 operation is 3%, which is bounded by the maximum number of plugged tubes per SG (8%) assumed in the RSG ECCS performance evaluation.
(iii) Extended Operation at Power Levels Between 50% and 100%
SONGS Unit 2 Cycle 17 safety analyses and LOCA analyses were evaluated for acceptability of plant operating at power levels between 50% and 100%, which bounds the planned operation at 70% power level. The impact of the extended reduced power operation was evaluated to determine the continued applicability of SONGS Units 2 and 3 ECCS performance AORs. It was concluded that the power operation range between 50%
and 100% remains bounded by the current SONGS Units 2 and 3 ECCS performance AORs for LBLOCA, SBLOCA, and post-LOCA LTC.
DETAILED SUPPORTING INFORMATION
- 1. Introduction The current AORs for SONGS Units 2 and 3 were performed for ZIRLO implementation with OSGs and supports up to 21.4% steam generator tube plugging (SGTP). In order to support application of the AORs to SONGS Units 2 and 3 with RSGs, an evaluation of the impact of RSGs with 8% SGTP on the SONGS Unit 2 and 3 ECCS performance analysis was prepared.
The evaluation considered the impact of the RSGs on the AORs for LBLOCA, SBLOCA, and post-LOCA LTC, and demonstrated conformance to the ECCS acceptance criteria for light water nuclear power reactors contained in 10 CFR 50.46. A reload analysis was prepared for SONGS Unit 2 Cycle 16 with RSGs. Then, for the following cycle, a reload analysis was prepared for SONGS Unit 2 Cycle 17.
The impact of the RSGs on the SONGS Units 2 and 3 ECCS performance AORs was evaluated through a two-step process. First, the design data of the RSGs, including thermal hydraulic characteristics, were compared to those of the OSGs as modeled in the ECCS performance AORs. Second, differences in design data, which were identified from the comparison, were evaluated for their impact on ECCS performance. The scope of the comparison considered all design features of the SGs that are modeled in the ECCS performance analysis.
This response to RAI 13 summarizes:
- i. the results of current AORs (Section 2).
ii. a comparison of SG parameters for ECCS Performance analysis (Section 3).
ENCLOSURE3 Page 4 of 16
iii. the results of the evaluation of the impact of RSGs on the SONGS ECCS performance analyses (Section 4).
iv. the applicability of the AORs to SONGS Unit 2 Cycle 16 (Section 5).
vi. the applicability of the AORs to SONGS Unit 2 Cycle 17 with reduced power operation (Section 7).
- 2. The Current AORs The current LBLOCA, SBLOCA, and Post-LOCA LTC AORs for SONGS Unit 2 supported operation of the OSGs with up to 21.4% SGTP. The limiting LBLOCA break was the 0.6 double ended guillotine break in the pump discharge leg (DEG/PD) and assumes 21.4% SGTP. The limiting SBLOCA was the 0.04 ft 2 break and assumes 30% SGTP. The post-LOCA Long-Term Cooling analysis assumed 30% SGTP. Peak Cladding Temperature (PCT), Peak Local Oxidation (PLO), and Core Wide Oxidation (CWO) for those analyses satisfied 10 CFR 50.46 Acceptance Criteria as given in Table 1.
Table 1 - SONGS Units 2 and 3 AOR Results for OSGs Analysis PCT PLO CWO LBLOCA 2170°F 15.3% <1%
SBLOCA 2077°F 14.1% <1%
- 3. Comparison of the OSGs and RSGs RSGs were installed in SONGS Units 2 and 3 for Cycle 16. Although the RSGs are considered to be in-kind replacements of the OSGs in terms of form, fit and function, the RSGs have more tubes compared to the OSGs (approximately 4% more), longer tubes (approximately [
]), thinner tube walls (approximately [ ]), larger inside diameter tubes
], [ ] outside diameter tubes, lower thermal conductivity material (Inconel 690, approximately 10% lower), larger primary side liquid volume (approximately [ ]).
Table 2 shows a comparison of parameters and percent differences between the RSGs and OSGs.
ENCLOSURE3 Page 5 of 16
Table 2 - Steam Generator Parameters for ECCS Performance Analysis Percent Description RSG OSG Difference
- 1. Number of tubes/SG (0% SGTP) 9,727 9,350 4.0
- 3. Heat transfer area (0% SGTP), ft 2 [ [ ] [
- 4. Tube bundle flow area (0% SGTP), ft 2 [ 1* [
- 5. Secondary side fluid 3 (water and [ ,
steam) volume, ft
- 6. Total SG metal mass, Ibm [ 1* [ ] [
SG Primary Side Water Volume
- 7. SG Primary Side Water Volume (0% ]* ]1
[ [1 1 1 SGTP), ft 3 SG Tube Elevations
- 8. Top of tube sheet elevation, inch [ 1* [ ]_ ---
- 9. Top of longest tube, at centerline, inch [ 1* [ ]_ ---
SG Tube Material
- 10. SG tube material I Inconel 690 Inconel 600 Other Components
- 11. SG Outlet Nozzle Flow Restrictor Yes No
[]* - Mitsubishi Heavy Industries, Ltd. Proprietary Class B information used with permission ENCLOSURE3 Page 6 of 16
Figure 1 shows a comparison as a function of temperature of the RSG and OSG Tubes Thermal Conductivity. The RSGs have Inconel 690. The OSGs have Inconel 600. The thermal conductivity of Inconel 690 is approximately 10% to 12% lower than Inconel 600.
Figure 1 Comparison of Thermal Conductivity of Inconel 690 (RSG) and Inconel 600 (OSG) 12 _
U.-
. 1 1.__* .. *t -.
o 8 -
C.,
I--
6 0 100 200 300 400 500 600 700 Temperature, degF F" - Inconel 690 --- n... Incone1600
- 4. Impact of the RSGs on the AOR ECCS Performance Analysis The impact of the RSGs on ECCS performance is evaluated from the effect of the following key parameters that summarize the impact of the differences noted in Table 2.
- i. Effect of the changes in SG tube plugging.
ii. Effect of the differences in SG primary and secondary side liquid inventory.
iii. Effect of the differences in elevation of SG components.
iv. Effect of the differences in SG total metal mass.
4.1 Impact of the RSGs on the LBLOCA AOR
- i. Effect of the changes in SG tube plugging.
ENCLOSURE3 Page 7 of 16
I ii. Effect of the differences in SG primary side liquid inventory.
The RSGs with 8% SGTP have [ ] in the SG primary side than the OSGs with 21.4% SGTP. As noted in Item 4.1.i, I
iii. Effect of the differences in SG secondary side liquid inventory.
The nominal[
] This ] LBLOCA ECCS performance analyses performed with the 1999 EM. This is iv. Effect of the differences in elevation of SG components.
The average SG tube length for the RSGs is [ ] The vertical rise for the longest tube for the RSGs is The differences in elevation ] since the flow in a LBLOCA is mostly homogeneous and [ I ENCLOSURE3 Page 8 of 16
- v. Effect of the differences in SG total metal mass.
The SG metal mass for the RSGs is analyses performed with the 1999 EM. This is demonstrated [
]
4.2 Impact of the RSGs on the SBLOCA AOR
- i. Effect of the changes in SG tube plugging.
I The ] of SGs for the RSGs has the [
due to the decrease of the core decay heat with time.
The ] RSG tubes have the [
] of loss of natural circulation.
ii. Effect of the differences in SG tube geometry and material.
I Rlal = D,0 1 n Do 2k,,~
1 D ENCLOSURE3 Page 9 of 16
where:
Rwai = tube wall resistance to heat transfer, (Btu/hr-ft 2 -OF)-'
Do= tube outside diameter, ft D= tube inside diameter, ft kwa,1 = tube material thermal conductivity, Btu/hr-ft-°F shows [ I compared to the OSGs at 5500 F. This [ ] since after the cessation of the subcooled forced convection mode of SG heat transfer early in the LOCA transient, the [ ] is generally the limiting resistance for SG heat transfer during a LOCA.
iii. Effect of the differences in SG primary side liquid inventory.
The RSGs with 8% SGTP have approximately [ ] SG primary side than the OSGs with 21.4% SGTP. As noted in Item 4.2.i
] in the primary sides of SGs for the RSGs [ ] of core uncovery and the subsequent less severe core uncovery due to the decrease of the core decay heat at a later time.
iv. Effect of the differences in SG secondary side liquid inventory.
The nominal secondary side liquid inventory for the RSGs is approximately
] SBLOCA calculations with the Supplement 2 Model (S2M, CENPD-1 37, Supplement 2-P-A, "Calculative Methods for the ABB CE Small Break LOCA Evaluation Model," April, 1998) are [ ]. The impact of the difference on the SG heat transfer [ ] and its impact on core uncovery or time of core uncovery is [ I
- v. Effect of the differences in elevation of SG components.
The average SG tube length for the RSGs is [ ] The vertical rise for the longest tube for the RSGs is [ ] the OSGs.
These differences in elevation [ ] on a SBLOCA event since the impact on the elevation head difference between the hot and cold sides of the SGs is negligible.
vi. Effect of the differences in SG total metal mass.
The SG metal mass for the RSGs is [ ] OSGs. This
] ECCS performance analyses performed with the S2M (CENPD-1 37, Supplement 2-P-A). SG secondary side wall heat is [ ] the secondary side and has [ ] on the RCS.
vii. Impact of the SG outlet nozzle flow restrictor on the Main Steam Safety Valves (MSSVs) flow rate.
The RSGs SG outlet nozzle flow restrictors that can potentially reduce the flow rate past the MSSVs. The OSGs do not have SG outlet nozzle flow restrictors. However, the OSG SBLOCA analysis [ I ENCLOSURE3 Page 10 of 16
would occur if the SG outlet nozzle flow restrictor ] Thus, the impact of the flow restrictors is [ I viii. Impact of RSGs on the break spectrum analysis.
The SBLOCA AOR determined the PCT by running the break spectrum analysis for the following breaks with OSGs and 30% SGTP, Break Size (ft") 0.03 0.04 0.05 Peak Cladding Temperature (°F) 1676 2077 1900 Maximum Cladding Oxidation (%) 5.14 14.11 10.96 Core-Wide Cladding Oxidation (%) <0.34 <0.74 <0.61
[
]
I The evaluation described above examined the impact of differences between OSGs and RSGs and concluded that the impact of RSGs with 8% SGTP
] The shape of the PCT vs. break size curve remains valid with the RSGs [
] Thus, the OSGs maximum PCT
]
4.3 Impact of the RSGs on the post-LOCA Long Term Cooling AOR The AOR post-LOCA LTC analysis with the OSGs was performed with the CENPD-254-P-A Evaluation Model (CENPD-254-P-A, "Post-LOCA LTC Evaluation Model," June 1980). The analysis is done with 30% SGTP.
Implementation of the RSGs ] The impact of the RSGs is as follows:
- i. Impact of SG heat transfer parameters.
In the LTC analysis, the amount of SG heat transfer is determined by the controlled cooldown, which is accomplished with the Atmospheric Dump Valves (ADVs). Given the simple RCS hydraulic models and primary-to-secondary heat transfer models of the CENPD-254-P-A evaluation model in conjunction with the small heat loads during the cooldown (in comparison to ENCLOSURE3 Page 11 of 16
the full power heat load for which the SGs are designed), the differences in data shown in Table 2 do not significantly impact the RCS response calculated in the post-LOCA LTC analysis. That is, the RSGs with 8% SGTP has [ ] than the OSGs with 30% SGTP and thus [ ] assumed in the AOR with OSGs.
ii. Effect of the differences in SG primary side liquid inventory.
The increase in water volume [ I In the boric acid precipitation portion of the post-LOCA LTC analysis, the increase in water volume impacts the initial boric acid concentration in the sump. The impact is insignificant since the increase in volume [ ] in comparison to the total volume of all the sources that contribute to the sump inventory (i.e., [
] Also, the boric acid concentration of the RCS [ ] all the sources of boric acid so it acts [ ] sump and, therefore, an increase in volume would tend [ ] (although, in this case, [ D.
For the post-LOCA LTC analysis with OSGs and 30% SGTP [
In the SBLOCA decay heat removal portion of the post-LOCA LTC analysis, [ ] RCS for those break sizes that are predicted to refill. However, the increase in water volume [ I significant impact on the range of break sizes that are predicted to refill (since it is the break size itself and the HPSI pump delivery curve, not the RCS water volume, that primarily determines for which break sizes the RCS is predicted to refill).
iii. Effect of the differences in SG total metal mass.
The SG metal mass for the Increasing the SG metal mass has an adverse impact on the post-LOCA SG/RCS cooldown (i.e., it prolongs the time required to cooldown the RCS to the shutdown cooling system entry temperature). However, the AOR has an [ ] This[
metal mass is more than sufficient to cover the approximately
] the SG/RCS metal mass [
mass of the RSGs relative to the OSGs.
4.4 Conclusions for the Evaluation of RSGs on AOR ECCS Performance Analysis The RSG LBLOCA evaluation with 8% SGTP is bounded by the LBLOCA AOR for OSGs with 21.4% SGTP and complies with the 10 CFR 50.46 Acceptance Criteria.
The RSG SBLOCA evaluation with 8% SGTP is bounded by the AOR SBLOCA analysis for OSGs with 30% SGTP and complies with the 10 CFR 50.46 Acceptance Criteria.
The RSG post-LOCA LTC evaluation with 8% SGTP is bounded by the AOR post-LOCA LTC evaluation with OSGs with 30% SGTP.
ENCLOSURE3 Page 12 of 16
- 5. Evaluation for SONGS Unit 2 Cycle 16 RSGs and AREVA Lead Fuel Assemblies (LFAs) were installed in SONGS Unit 2 prior to the beginning of Cycle 16. The AOR analyses with OSGs bound and remain applicable for RSGs with up to 8% SGTP as assumed for the RSGs. An increase in the PCT is added to bound mixed core effects caused by the addition of AREVA LFAs. PCT, PLO, and CWO for SONGS Unit 2 Cycle 16 satisfy 10 CFR 50.46 Acceptance Criteria as given in Table 3.
Table 3 - SONGS Unit 2 Cycle 16 Results Analysis PCT PLO CWO LBLOCA 2174°F 15.3% <1%
SBLOCA 2077°F 14.1% <1%
The impact of RSGs is [ ] LBLOCA and SBLOCA analyses [
for the post-LOCA LTC analysis as described Section 4.
The impact of the presence of the AREVA LFAs was evaluated by means of a analysis for LBLOCA that represented the difference in flow resistance of the Westinghouse and AREVA fuel assemblies. A [ I The presence of AREVA LFAs has [ ] on the SBLOCA and post-LOCA LTC analyses since there [ ] effects in these events.
The impact of [ ] fuel performance data was explicitly evaluated for the LBLOCA analysis by recalculating input data from the Cycle 16 fuel performance data and rerunning the AOR with the Cycle 16 fuel performance data that demonstrate [ ] the AOR.
The impact of [ ] fuel performance for the SBLOCA was demonstrated by recalculating input data with the Cycle 16 fuel performance data and showing [
by the AOR.
] fuel performance data has [ ] the post-LOCA LTC analysis.
Other cycle specific changes, like changes in the minimum containment spray implemented for SONGS Cycle 16, [ ] on the post-LOCA LTC Analysis.
5.1 Conclusions for SONGS Unit 2 Cycle 16 The SONGS Unit 2 LBLOCA, SBLOCA, and post-LOCA LTC AORs, with a PCT delta of 4 0 F for the LBLOCA analysis remain bounding for SONGS Unit 2 Cycle 16.
- 6. Evaluation for SONGS Unit 2 Cycle 17 The SONGS Unit 2 Cycle 17 analysis includes eight first burn AREVA LFAs, eight second burn AREVA LFAs, and eight Westinghouse first burn Modified Standard Design (MSD) LFAs. In addition the analysis supports the cold leg temperature restoration from 541 OF to 550 0 F. Similar to the analysis for Cycle 16, an increase in PCT was added to bound the mixed core effect caused by the addition of AREVA and Westinghouse LFAs. PCT, PLO, and CWO for SONGS Unit 2 Cycle 17 satisfy 10 CFR 50.46 Acceptance Criteria as given in Table 4.
ENCLOSURE3 Page 13 of 16
Table 4 - SONGS Unit 2 Cycle 17 Results Analysis PCT PLO CWO LBLOCA 2174°F 15.4% <1%
SBLOCA 2077°F 14.1% <1%
The impact of the presence of the eight additional AREVA LFAs and eight Westinghouse MSD LFAs was evaluated by means of a LBLOCA [ ] that represented the difference in flow resistance of the Westinghouse and AREVA fuel assemblies.
I The presence of AREVA and Westinghouse LFAs has no effect on the SBLOCA and post-LOCA LTC analyses since there [ ] effects in these events.
The impact of [ ] fuel performance data was explicitly evaluated for the LBLOCA analysis by recalculating input data from the Cycle 17 fuel performance data and rerunning the AOR with the Cycle 17 fuel performance data for TCOLD restored to 550°F that demonstrate that it is bounded by the AOR.
The impact of [ ] fuel performance for the SBLOCA was demonstrated by recalculating input data with the Cycle 17 fuel performance data and showing that it is bounded by the AOR.
Differences in fuel performance data have [ ] the post-LOCA LTC analysis.
The impact of the change in the initial pressurizer level for the LBLOCA and SBLOCA analyses for Cycle 17 as a result of the TCOLD restoration to 550°F was demonstrated [ ] by the AOR.
Restoration to TCOLD to 550°F [ ] the LBLOCA and SBLOCA analyses since the AORs are performed using [
] cold leg temperatures that are not changed.
Other plant cycle specific changes, like differences in the condensate storage tank liquid temperature implemented for Cycle 17, have [ ] the post-LOCA LTC analysis.
6.1 Conclusions for SONGS Unit 2 Cycle 17 The SONGS Unit 2 LBLOCA, SBLOCA, and post-LOCA LTC AORs, with a PCT
] the LBLOCA analysis remain bounding for SONGS Unit 2 Cycle 17.
ENCLOSURE3 Page 14 of 16
- 7. Evaluation for Extended Operation at Power Levels Between 50% and 100%
Appendix K ECCS Performance Analyses are performed at 100% power plus uncertainty.
SONGS Unit 2 Cycle 17 LOCA analyses were evaluated for acceptability of plant operation at power levels between 50% and 100%, which includes the planned operation at 70% power level.
7.1. LBLOCA Evaluation at Power Levels Between 50% and 100%
The LBLOCA analysis for SONGS Unit 2 with the 1999 EM calculates PCT during reflood. Key parameters that impact the LBLOCA transient response are initial power, peak linear heat generation rate (PLHGR) and initial stored energy in the core. Initial stored energy in the core has a [
] that is limiting for SONGS Unit 2. Lowering the initial power results in lower stored energy in the core at the end of blowdown, which coupled with the lower decay heat (a multiple of the initial power) [ ] steaming rate during reflood. This results in an [ ] reflood rate, which yields [ ] The initial stored energy in the core is calculated by [ ] the fuel performance time in life dependent FATES3B (CENPD-139-P-A, "Fuel Evaluation Model," July 1974) data file to the 1999 EM codes input files.
In summary, for the LBLOCA event, lower initial power yields [
The AOR fuel performance input data for 100% power [ ] for low power operation.
7.2 SBLOCA Evaluation at Power Levels Between 50% and 100%
The SBLOCA analysis for SONGS Unit 2 with the S2M calculates PCT during the time of maximum core uncovery. Key parameters that impact the SBLOCA PCT are [
] Reducing the initial power [ ] in the core. This [ ] amount of core uncovery and [ ] the uncovered region of the core yielding I
Hence, for the SBLOCA event, lower initial power yields [
The AOR fuel performance input data for 100% power [ ] for low power operation.
7.3 Post-LOCA Long Term Cooling Evaluation at Power Levels Between 50% and 100%
The boric acid precipitation analysis portion of the post-LOCA LTC analysis uses the decay heat for 100% power which is conservative since it produces larger evaporation which increases the core boron concentration. Thus, the AOR for 100% power [ ] for reduced power operation.
The decay heat portion of the post-LOCA LTC analysis accounts for the ADVs during calculation of the cooldown of the system. The cooldown at 100% power [ ] cooldown for lower initial powers since the decay heat for lower powers is proportionally lower. Thus, the AOR [ ] results for reduced power operation.
ENCLOSURE3 Page 15 of 16
7.4 Conclusions for Operation at Power Levels Between 50% and 100%
The impact of the extended reduced power operation was evaluated to determine the continued applicability of SONGS Units 2 and 3 ECCS performance AORs at 100% power. It was concluded that the power operation range between 50% and 100%
ENCLOSURE3 Page 16 of 16