BSEP 04-0035, Response to RAI Regarding Technical Specification (Ts), 2.1.1.2, Reactor Core Minimum Critical Power Ratio Safety Limit and Revision to References in TS 5.6.5, Core Operating Limits Report (COLR)
| ML040720651 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/04/2004 |
| From: | Gannon C Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BSEP 04-0035, TAC MC1249, TSC-2003-07 | |
| Download: ML040720651 (14) | |
Text
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S..
Cornelius J. Gannon Progrss E
ergyVice President Brunswick Nuclear Plant 4Progress Energy Carolinas. Inc.
MAR 04 2004 SERIAL: BSEP 04-0035 TSC-2003-07 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Brunswick Steam Electric Plant, Unit No. 1 Docket No. 50-325/License No. DPR-71 Response to Request for Additional Information Technical Specification 2.1.1.2, Reactor Core Minimum Critical Power Ratio Safety Limit and Revision to References in Technical Specification 5.6.5, Core Operating Limits Report (COLR)
(NRC TAC No. MC1249)
Reference:
Letter from John S. Keenan to U.S. Nuclear Regulatory Commission (Serial: BSEP 03-0148), "Request for License Amendment - Technical Specification 2.1.1.2, Reactor Core Minimum Critical Power Ratio Safety Limit and Revision to References in Technical Specification 5.6.5, Core Operating Limits Report (COLR)," dated October 31, 2003 Ladies and Gentlemen:
On October 31, 2003, Carolina Power & Light Company, now doing business as Progress Energy Carolinas, Inc. (PEC) requested a license amendment for the Brunswick Steam Electric Plant (BSEP), Unit No. 1. The proposed license amendment would: (1) revise the Technical Specification (TS) 2.1.1.2 minimum critical power ratio (MCPR) safety limit value for both two and single recirculation loop operation and (2) add topical report NEDE-32906P-A, "TRACG Application for Anticipated Operational Occurrences (AOO)
Transient Analyses," to the TS 5.6.5 list of approved methodologies used to determine the core operating limits.
On February 10, 2004, the NRC provided an electronic request for additional information (RAI) concerning this request. The electronic RAI was subsequently discussed and revised during telephone calls held on February 18, February 24, and February 26, 2004. The RAI consists of six questions.
Enclosure I provides responses to RAI Questions 1 through 5. RAI Questions 1 through 5 relate to the Cycle 14 and Cycle 15 limiting exposure point, comparison of Cycle 14 and 15 core and bundle power distributions, power shaping uncertainties and biases for Cycle 15, comparison of Cycle 14 and Cycle 15 analytical codes and methods, and the core P.O.
Box 10429 Southport. NC 28461 T> 910.457.3698 F> 910.457.2803
5 Document Control Desk BSEP 04-0035 / Page 2 monitoring software being used for Cycle 15 and the associated accounting of power distribution uncertainties. RAI Question 6, which pertains to the Cycle 15 operating strategy and the applicability of analytic methods used for evaluating the operating cycle, will be answered in a separate submittal. contains information that Global Nuclear Fuel - Americas, LLC (GNF-A) considers to be proprietary as defined by 10 CFR 2.390. GNF-A, as the owner of the proprietary information, has executed the affidavit provided in Enclosure 2, which identifies that the enclosed proprietary information has been handled and classified as proprietary, is customarily held in confidence, and has been withheld from public disclosure. GNF-A requests that the enclosed proprietary information be withheld from public disclosure in accordance with the provisions of 10 CFR 2.390 and 9.17. A non-proprietary (i.e., redacted) version of the response is provided in Enclosure 3.
In accordance with 10 CFR 50.91(b), PEC is providing the State of North Carolina a copy of this letter.
Please refer any questions regarding this submittal to Mr. Edward T. O'Neil, Manager -
Support Services, at (910) 457-3512.
Sincerely Cornelius J. Gannon WRM/wrm
Enclosures:
- 1. Response to Request for Additional Information (Proprietary Information)
- 3. Response to Request for Additional Information (Non-proprietary Version)
Document Control Desk BSEP 04-0035 / Page 3 William C. Noll, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, and agents of Carolina Power &
Light Company.
Notary (Seal)
My commission expires: OQ u5k Z',
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Document Control Desk BSEP 04-0035 / Page 4 cc (with all enclosures):
U. S. Nuclear Regulatory Commission, Region 11 A1ITN: Mr. Luis A. Reyes, Regional Administrator Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, GA 30303-8931 U. S. Nuclear Regulatory Commission ATTN: Mr. Eugene M. DiPaolo, NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission (Electronic Copy Only)
ALTN: Ms. Brenda L. Mozafari (Mail Stop OWFN 8G9) 11555 Rockville Pike Rockville, MD 20852-2738 cc (with Enclosures 2 and 3 only):
Ms. Jo A. Sanford Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510 Ms. Beverly 0. Hall, Section Chief Radiation Protection Section, Division of Environmental Health North Carolina Department of Environment and Natural Resources 3825 Barrett Drive Raleigh, NC 27609-7221
tN BSEP 04-0035 Response to Request for Additional Information (Non-Proprietary Version)
DOCKET 50-325 Response to Request for Additional Information Brunswick Unit 1, Cycle 15 to Support Tech Spec SLMCPR March 4, 2004 RESPONSE to REQUEST FOR ADDITIONAL INFORMATION RELATING TO PROPOSED AMENDMENT TO LICENSE NO. DPR-71 PROGRESS ENERGY BRUNSWICK UNIT NO. 1 DOCKET NO. 50-325 NRC Otestion 1 Limiting Cycle Exposure Point: For the upcoming Cycle 15, the calculated MIP value for Unit I occurs at BOC. The submittal cites the MIP factors for Cycle 15 and Cycle 14 in order to compare the flatness of the bundle to bundle or core wide power distribution. The submittal compares the MIP for Cycle 14 calculated at EOC - 2000 with the MIP for Cycle 15 calculated at BOC.
- a.
Explain why these exposure points are most limiting in terms of the MIP factor for each cycle.
Identify the core design, rod pattern, or operation features that affected the change in the limiting exposure point for Cycle 15 in comparison to Cycle 14.
- b.
State if in fact the cited MIP factors are based on the limiting conditions. State if the limiting MIP and RIP for Cycle 15 are based on the rated condition or off-rated conditions.
Response to NRC Ouestion I Response to I a:
The values calculated for ((
)). The flatness of the distribution at any condition is dependent on a number of factors, all of which change from cycle exposure point to point and cycle to cycle. Some of these factors are: the core radial bundle reactivity distribution which is determined by the enrichment of the reload and legacy fuel bundles, the amount and concentration of gadolinia contained in the bundles, the control blade sequences history, etc. The resulting bundle-by-bundle core power distribution is a by product of the requirement for the core to meet all licensing limits and to operate economically with desired operational flexibility.
Cycle 14 was the first introduction of GE14 into the Brunswick Unit I core. To maintain a flat bundle-by-bundle core power peaking, Cycle 14 utilized GE 14 reload fuel bundles, with lower gadolinia poison loading, higher BOC reactivity near the core periphery and bundles with higher gadolinia poison loading, lower relative BOC reactivity scattered throughout the interior of the core configuration. This led to participation of only the GE14 bundles in the SLMCPR evaluation throughout the cycle with highest participation at end of rated (EOR). Many of the GE14 bundles scattered across the interior of core that participated in the SLMCPR evaluation reached maximum power about the same time and with similar bundle power levels. This resulted in a flat EOR bundle-by-bundle core power distribution, with the ((
)) for the cycle. Cycle 15 also loaded GE14 as the reload fuel (2nd GE14 reload) and utilized a similar core configuration to maintain a flat bundle-by-bundle core power peaking: lower gadolinia, higher reactivity core periphery; higher gadolinia, lower relative reactivity, scattered bundle core interior. Again, only the new reload GE14 bundles participate in the SLMCPR evaluation throughout the cycle. But this particular loading, flow and control blade sequence core configuration
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-i DOCKET 50-325 Response to Request for Additional Infornation Brunswick Unit 1, Cycle 15 to Support Tech Spec SLMCPR March 4, 2004 and operation results in the flattest GE14 reload bundle-by-bundle power distribution occurring at the BOC ((
].
The Brunswick I Cycle 14 and Cycle 15 bundle and core designs were developed to meet entirely different design constraints. The control blade sequencing in Cycle 15 was "Conventional" while the Cycle 14 sequencing was "Control Cell", resulting in more frequent changes of control blade sequences in Cycle 15. Cycle 14 was designed for 105% original rated power at BOC, uprate at mid-cycle to 112%
rated power with the first reload of GE14, a flow window of 91.1 - 104.3% rated flow and a design OLMCPR of 1.42 at BOC changing later in the cycle to 1.48 (ODYN methodology). Cycle 15 was designed for full 120% EPU during the entire cycle with a second reload of GE14, a flow window of 88.8-104.5% rated flow and a design OLMCPR of 1.28 at BOC changing later in the cycle to 1.33 (TRACG methodology). For these cycles, the reload bundles, core configurations, control blade sequencing and core flow changes were designed to meet existing or projected operating license thermal limits (LHGR, MCPR), reactivity limits (CSDM and SLCS) and provide operating flexibility while optimizing fuel economy. The simulated core operation for the two cycles resulted in different core isotopics as each cycle progressed, resulting in different core radial and axial power profiles. The SLMCPR evaluation accounts for all of the differences between the cycles, because it directly utilizes the simulation results as input to the evaluation. The combined effect of all of the differences in the core configuration, at the various exposure points ((
Response to lb:
NRC Question 2 Core and Bundle Power Distribution: Considering the uncontrolled bundle pin-by-pin power distribution, the previous Cycle 14 represents the limiting case in comparison to Cycle 15. Explain why the limiting bundle pin-by-pin power distribution for Cycle 15 is lower than pin-by-pin power distribution for Cycle 14. Explain why the R-factors calculated for Cycle 15 are lower than the R-factors for the previous Cycle 14 (EPU operation core design). In addition, discuss the differences in the bundles loaded in Cycle 15 in comparison with Cycle 14 and explain how these differences contributed to the lower R-factor. Explain why the core design intended to meet the energy needs for operation at the expanded EPU operating domain for the same cycle length would require less flat or more skewed pin-by-pin power distribution than the previous EPU operation cycle.
Response to NRC Question 2 The Cycle 15 limiting exposure point is at BOC. The Cycle 14 limiting exposure point is at EOR, near EOC. The pin-by-pin power distribution flattens from BOC to EOR as bundle exposure increases.
Similarly the pin-by-pin R-factor distribution flattens ((
)) as bundle exposure increases.
This bundle behavior as exposure increases is typical and results in a ((
)) at the EOR exposure point where the SLMCPR is limiting for Cycle 14, compared to Cycle 15 at its BOC exposure point where the SLMCPR is limiting for Cycle 15.
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DOCKET 50-325 Response to Request for Additional Information Brunswick Unit 1, Cycle 15 to Support Tech Spec SLMCPR March 4, 2004 The bundle designs placed into CPR limiting positions for both Cycles 14 and 15 need to have the characteristics to flatten the R-factors as exposure increases to meet CPR margin requirements. The R-factor distribution for the Cycle 15 limiting bundles is similar at BOC ((
)) to the Cycle 14 limiting bundles at BOC ((
)). By EOR, the Cycle 15 limiting bundles have a flattened R-factor distribution ((
)) but not quite as flat as the Cycle 14 limiting bundles
((
)) at EOR.
The reload fuel loaded into Cycle 15 was the 2 nd batch of the higher enriched, more efficient, greater bundle mass GE14 design, compared to the GE13 fuel it is replacing. The combination of use of the more economic GE14 design along with operation down to as low as 88.8% rated core flow, with its accompanying improved efficiency, produces greater cycle energy, compared to that produced during Cycle 14, to be able to operate the majority of the cycle at the 120% EPU condition. With a lower OLMCPR for Cycle 15 due to use of TRACG AOO methodology, greater peripheral pin peaking, due to the use of the high GE14 bundle enrichment, can still be tolerated at 120% EPU and 85% rated core flow conditions. A more efficient bundle utilizes higher pin peaking on the periphery. The combination of the lower OLMCPR and the desire for greater bundle efficiency resulted in a Cycle 15 central bundle that has a slightly more peaked pin-by-pin power and R-factor distribution compared to the Cycle 14 bundle, as was discussed above.
The impact of the R-factor distribution as a function of exposure is explicitly accounted for in the SLMCPR evaluation. The evaluation for Cycle 15 resulted in a SLMCPR = 1.11 that is lower than the Cycle 14 SLMCPR = 1.12 by 0.01. This magnitude of reduction in SLMCPR is ((
more thoroughly discussed in the response to NRC Question 5.
NRC Ouestion 3 Increase in the GEXL Uncertainties: The amendment requests states that for the Unit I Cycle 15 core, higher GEXL uncertainties and biases are not required, because the power shapes for the cycle do not correspond to the power shapes requiring the higher biases. Does this mean that Unit I Cycle 15 would not be operated in such a manner that double humped, inlet or outlet peaked power shapes would not occur? Please, state the reason that the Cycle 15 power shapes would not require correction to account for lack of experimental data.
Response to NRC Question 3 The axial power shapes are dominated primarily by the bundle design and secondarily by the core operation. The axial power shape is assessed for each evaluated (BOC, peak hot excess (PHE) and EOR) cycle exposure point. Each cycle exposure point is evaluated using the approved SLMCPR methodology. ((
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DOCKET 50-325 Response to Request for Additional Information to Support Tech Spec SLMCPR Brunswick Unit 1, Cycle 15 March 4, 2004 NRC Ouestion 4 Use of Different Analytical Method: State if different analytical method, codes, uncertainty calculation methods or licensing methodology approach was used for Cycle 15 relative to Cycle 14 in the SLMCPR calculation method. If there are changes in the analytical methods or codes, explain how these changes contributed to the large differences in the % RIP for the two cycles. Also, Table 1 shows that a revised power distribution uncertainty method was used for Cycle 15, but it did not state the specific method.
State what revised method was used. Please, provide sufficient information for the staff make its safety finding.
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DOCKET 50-325 Response to Request for Additional Information Brunswick Unit 1, Cycle 15 to Support Tech Spec SLMCPR March 4, 2004 Response to NRC Question 4 As stated in line 13 of Table 1: Comparison of the Brunswick Unit I Cycle 15 and Cycle 14 SLMCPR in the Additional Information Regarding the Cycle Specif ic SLMCPR for Brunswick Unit I Cycle is, 26 September 2003 contained in the October 31, 2003 amendment request, the approved revised analytical methodology in NEDC-32601 P-A was utilized for the Cycle 15 SLMCPR evaluation compared to Cycle 14 which used the GETAB methodology. The GESAM computer code was used to determine both the Cycle 14 and Cycle 15 SLMCPRs. GESAM can apply either the Revised or the GETAB methodology.
)). This method is described in detail in NEDC-3260 IP-A, section 2.10 on pages 2-8 and 2-9. A comparison of the SLMCPR calculated using the Revised methodology to that calculated using the GETAB methodology is discussed on pages 4-7 and 4-8, with results provided in Table 4.1 on page 4-8. ((
]I. For a GETAB calculated SLMCPR = 1.12 which corresponds to the Brunswick Unit I Cycle 14 value, ((
)), which is consistent with the decrease observed in going from Brunswick Unit I Cycle 14 to Cycle 15.
NRC Question 5 3D-MONCORE/POWERPLEX: State if Brunswick Unit 1 uses CASMO4/MICROBURN-B2 or earlier versions. Since the GE SLMCPR methodology uses the power distribution uncertainty specified in NEDC-32694P-A, "Power Distribution Uncertainties for Safety Limit MCPR Evaluations," explain how the differences in the uncertainties associated with the use of different core monitoring system is taken into account. Are the NRC-approved GE methods specified in NEDC-32694P-A applicable to Brunswick Unit 1 EPU Cycle 14 or the upcoming Cycle 15? For plants using another vendor's core monitoring system, is there a NRC-approved GE method for uncertainty treatments when performing the SLMCPR calculations.
Response to NRC Question 5 Brunswick Unit 1 uses the CASMO3G/MICROBURN-B methodology as approved in Topical Report XN-NF-80-19 (P)(A), Supplement 3 and Supplement 4 (11/90) The reduced power distribution uncertainties specified in NEDC-32694P-A are not used in the determination of SLMCPR for plants that do not utilize the 3D Monicore monitoring system unless they have been demonstrated to be applicable.
The higher GETAB uncertainties (more conservative) were used for both Brunswick Unit 1 EPU Cycle 14 and Cycle 15 evaluations and have been confirmed by PGN to bound those of the POWERPLEX-I1 (CASMO-3G/MICROBURN-B) Core Monitoring Software System.
All SLMCPR evaluations for plants using another vendor's core monitoring system, to date, have been performed using the NRC approved GE methodology with existing GETAB or Revised Uncertainties (other than the power uncertainties) or with higher uncertainties that are justified by the responsible Utility.
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BSEP 04-0035 Global Nuclear Fuel - Americas, LLC Affidavit of Proprietary Information
Affidavit Affidavit I, Margaret E. Harding, state as follows:
(1) I am Manager, Fuel Engineering Services, Global Nuclear Fuel - Americas, L.L.C. ("GNF-A") and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding.
(2) The information sought to be withheld is contained in the attachment, "Response to Request for Additional Information Relating to Proposed Amendment to License No. DPR-71 Progress Energy Brunswick Unit No. I Docket No. 50-325" dated March 4, 2004. GNF proprietary information is indicated by enclosing it in double brackets. In each case, the superscript notation (3) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination.
(3) In making this application for withholding of proprietary information of which it is the owner or licensee, GNF-A relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOLA"), 5 USC Sec. 552(b)(4), and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4) and 2.390(a)(4) for "trade secrets and commercial or financial information obtained from a person and privileged or confidential" (Exemption 4). The material for which exemption from disclosure is here sought is all "confidential commercial information," and some portions also qualify under the narrower definition of "trade secret," within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energ, Project v. Nuclear Regulatory Commission, 975F2d871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704F2dl280 (DC Cir. 1983).
(4) Some examples of categories of information which fit into the definition of proprietary information are:
- a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GNF-A's competitors without license from GNF-A constitutes a competitive economic advantage over other companies;
- b. Information which, if used 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 of a similar product;
- c. Information which reveals cost or price information, production capacities, budget levels, or commercial strategies of GNF-A, its customers, or its suppliers;
- d. Information which reveals aspects of past, present, or future GNF-A customer-funded development plans and programs, of potential commercial value to GNF-A;
- e. Information which discloses patentable subject matter for which it may be desirable to obtain patent protection.
wA
^
Affidavit The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraphs (4)a. and (4)b., above.
(5) To address the 10 CFR 2.3 90 (b) (4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a sort customarily held in confidence by GNF-A, and is in fact so held. Its initial designation as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set forth in (6) and (7) following. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GNF-A, no public disclosure has been made, and it is not available in public sources. All disclosures to third parties including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or proprietary agreements which provide for maintenance of the information in confidence.
(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or subject to the terms under which it was licensed to GNF-A. Access to such documents within GNF-A is limited on a "need to know" basis.
(7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist or other equivalent authority, by the manager of the cognizant marketing function (or his delegate), and by the Legal Operation, for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GNF-A are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary agreements.
(8) The information identified in paragraph (2) is classified as proprietary because it contains details of GNF-A's fuel design and licensing methodology.
The development of the methods used in these analyses, along with the testing, development and approval of the supporting methodology was achieved at a significant cost, on the order of several million dollars, to GNF-A or its licensor.
(9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GNF-A's competitive position and foreclose or reduce the availability of profit-making opportunities. The fuel design and licensing methodology is part of GNF-A's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost.
The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expertise to determine and apply the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods.
The research, development, engineering, analytical, and NRC review costs comprise a substantial investment of time and money by GNF-A or its licensor.
Affidavit The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial.
GNF-A's competitive advantage will be lost if its competitors are able to use the results of the GNF-A experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.
The value of this information to GNF-A would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GNF-A of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools.
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 at Wilmington, North Carolina, this 4th day of
- March, 2004.
Margaret E. Harding Ae Global Nuclear Fuel - Americas,