TSTF-17-12, Technical Specifications Task Force - Transmittal of TSTF-564, Safety Limit Mcpr.

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Technical Specifications Task Force - Transmittal of TSTF-564, Safety Limit Mcpr.
ML17240A265
Person / Time
Site: Technical Specifications Task Force
Issue date: 08/28/2017
From: Gustafson O, Morris J, Vaughan J, Linda Williams
Technical Specifications Task Force
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
TSTF-17-12 TSTF-564
Download: ML17240A265 (56)
v • d • e


Text

{{#Wiki_filter:TECHNICAL SPECIFICATIONS TASK FORCE A JOINT OWNERS GROUP ACTIVIT Y TSTF

28-Aug-17 28-Aug-17 TSTF-5 64, Rev. 0 Page 1 1.

SUMMARY

DESCRIPTION The Technical Specification (TS) Safety Limit (SL) value and method of calculation for the Minimum Critical Power Ratio (MCPR) limit, SL 2.1.1.2, is revised for Boiling Water Reactor (BWR) plants using Global Nuclear Fuel or Westinghouse fuel. The proposed change is not applicable to plants using Areva fuel. The revised calculation method is based on using the Critical Power Ratio (CPR) data statistics and is revised from ensuring that 99.9% of the rods would not be susceptible to transition boiling to ensuring that there is a 95% probability at a 95% confidence level that no rods will be susceptible to transition boiling. The revised MCPR SL is consistent with the regulatory requirements while being cycle -independent, thereby minimizing the need for TS license amendment requests to revise this value for each operating cycle.

2. DETAILED DESCRIPTION 2.1. Current Design and Licensing Basis MCPR is defined in Section 1.1 of the BWR TS as: The MCPR shall be the smallest critical power ratio (CPR) that exists in the core [for each class of fuel]. The CPR is that power in the assembly that is calculated by application of the appropriate correlation(s) to cause some point in the assembly to experience boiling transition, divided by the actual assembly operating power.

The onset of transition boiling is a phenomenon that is readily detected during the testing of various fuel bundle designs. Based on these experimental data, correlations are developed to predict critical bundle power (i.e., the bundle power level at the onset of transition boiling) for a given set of plant parameters (e.g., reactor vessel pressure, flow, and subcooling). Although fuel damage does not necessarily occur if a fuel rod experiences transition boiling, the critical power at which boiling transition is calculated to occur has been adopted as a fuel design criterion . Because plant operating conditions and bundle power levels are monitored and determined relatively easily, monitoring the MCPR is a convenient metric for ensuring that fuel failures due to inadequate cooling do not occur. The TS contain two limits on MCPR: a safety limit (herein referred to as the SLMCPR) and a Limiting Condition for Operation (LCO) operating limit (herein referred to as the OLMCPR). Title 10 of the Code of Federal Regulations (10 CFR), Part 50, paragraph 50.36(c)(1) defines "safety limits " as limits upon important process variables that are found to be necessary to reasonably protect the integrity of certain of the physical barriers that guard against the uncontrolled release of radioactivity. In the case of the MCPR safety limit, the physical barrier being protected is the fuel rod cladding. The current SLMCPR is calculated as the point at which 99.9% of the fuel rods are not susceptible to transition boiling (i.e., reduced heat transfer) during normal operation and anticipated operational occurrences, herein referred to as MCPR R99.9%R. The MCPR R99.9%R limit is calculated for each BWR on a cycle -by-cycle basis using approved methodologies. A n LCO is defined in 10 CFR 50.36(c)(2) as the lowest functional capability or performance level of equipment required for safe operation of the facility. The OLMCPR LCO is required to TSTF-5 64, Rev. 0 Page 2 be met to ensure that no fuel damage results during anticipated operational occurrences (AOOs). To ensure that the measured MCPR does not exceed the SLMCPR during any AOO that occurs with moderate frequency, transients are analyzed to determine the largest reduction in critical combined with the MCPR R99.9%R value to determine the OLMCPR LCO limit. Together, SLMCPR and OLMCPR ensure that no fuel damage occurs due to transition boiling during normal operation or AOOs. 2.2. Current Technical Specifications Requirements NUREG-1433 and NUREG -1434 P0F 1 P , Safety Limit 2.1.1.2 states: 2.1.1.2 With the reactor steam dome pressure 785 psig and core flow 10% rated core flow: MCPR shall be [1.07] for two recirculation loop operation or [1.08] for single recirculation loop operation. The values in brackets, [1.07] and [1.08], are plant -specific limits. The reactor steam dome pressure and core flow values are also plant-specific and differences do not affect the applicability of the proposed change. NUREG-1433 and NUREG -1434, LCO 3.2.2, "Minimum Critical Power Ratio (MCPR)," states: All MCPRs shall be greater than or equal to the MCPR operating limits specified in the [Core Operating Limits Report] COLR. NUREG-1433 and NUREG -1434, LCO rated thermal power. Plant-specific TS may have a different Applicability, which does not affect the justification for the proposed change. NUREG-1433 and N UREG-1434, TS 5.6.3, "Core Operating Limits Report," states:

a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following:

[The individual specifications that address core operating limits must be referenced here.]

1 NUREG-1433 is based on the BWR/4 plant design, but is also applicable of the BWR/2, BWR/3, and, for some requirements, to the BWR/5 plant designs. NUREG -1434 is based on the BWR/6 plant design, and is applicable, for some requirements, to the BWR/5 plant design. TSTF-5 64, Rev. 0 Page 3 2.3. Reason for the Proposed Change The current SLMCPR (i.e., MCPR R99.9%R) is affected by the cycle -specific design, such as core power distribution, fuel type, and operating power -flow domain. These factors generally vary enough from cycle -to-cycle that changes to the SLMCPR TS values are common. The subsequent cycle core design is dependent on the core burnup of the previous cycle. As a result, the core design for the subsequent cycle is typically finalized late in the previous fuel cycle. Consequently, license amendment requests to modify the SLMCPR typically request an accelerated NRC review (i.e., less than the typical period of one year) to support the scheduled start of the subsequent fuel cycle. A review of the NRC Agency -wide Documents Access and Management System (ADAMS) identified a number of approved license amendments to revise the SLMCPR in 2015 and 2016. The Babcock & Wilcox, Westinghouse, Combustion Engineering, and Advanced Passive 1000 (AP1000 PP) Standard Technical Specifications (NUREG-1430, NUREG -1431, NUREG -1432, and NUREG-2194) safety limits on fuel cladding are based on a Departure from Nucleate Boiling Ratio (DNBR) limit. The PWR DNBR limits are roughly analogous to the BWR SLMCPR, in that both protect fuel cladding integrity from inadequate cooling. The PWR DNBR safety limit corresponds to a 95% probability at a 95% confidence level that DNB will not occur, vice the BWR SLMCPR that is based on ensuring that 99.9% of the fuel rods will not be susceptible to boiling transition. Either approach is statistically valid, but this difference results in a PWR safety limit that is only dependent on the fuel type(s) in the reactor and the corresponding DNBR correlations. The PWR DNBR Safety Limits are not cycle dependent and are typically only revised when the type of fuel changes. 2.4. Description of the Proposed Change The proposed change revises the standard TS in NUREG-1433 and NUREG -1434 for all BWR plants using Global Nuclear Fuel or Westinghouse fuel. The proposed change is not applicable to BWR plants using AREVA fuel due to differences in core reload design methodology. The proposed change substantially reduce s the need for cycle -specific changes to the SLMCPR and eliminates the need for accelerated NRC review of those changes . The NUREG-1433 and NUREG -1434 Safety Limit 2.1.1.2 is revised to state: 2.1.1.2 core flow: MCPR [for two recirculation loop operation single recirculation loop operation ]. The phrase " [1.08] for single recirculation loop operation" are shown in brackets to retain compatibility for BWR plants that do not adopt the proposed change. The proposed SLMCPR methodology is not dependent on the number of TSTF-5 64, Rev. 0 Page 4 recirculation loops in operation, so the distinction between a single loop and two loop operation is not needed. Plants adopting the proposed change will revise their plant -specific SL to state: 2.1.1.2 core flow: MCPR The bracketed limit "[1.07]" will be replaced with a revised SLMCPR that ensur es there is a 95% probability at a 95% confidence level that no rods will be susceptible to transition boiling, and is referred to as SLMCPR R95/95 R. The reactor steam dome pressure and core flow values are also plant-specific. Differences between the Standard Technical Specifications values and the plant -specific values do not affect the applicability of the proposed change. For plants with Global Nuclear Fuel or Westinghouse fuel, the single SLMCPR R95/95 R is based on the fuel type in the reactor core. Table 1: Proposed MCPR R95/95 R Values by Vendor and Fuel Bundle Type Vendor Fuel Type Proposed MCPR R95/95 Global Nuclear Fuel GE14 1.0 5 Global Nuclear Fuel GNF2 1.07 Global Nuclear Fuel GNF 3 1.07 Westinghouse Optima2 1.06 Westinghouse Optima3 1.06 The derivation of these values is described in proprietary letters to the NRC from Global Nuclear Fuel and Westinghouse (References 1 and 2). When new fuel types are developed, the fuel vendor will describe to the NRC the derivation of the MCPR R95/95 R value for that fuel type. This description may be referenced by a licensee requesting a change to SLMCPR R95/95 R. For cores loaded with a mix of applicable fuel types, the SLMCPR R95/95 R is based on the largest (i.e., most limiting) of the MCPR R95/95 R values for the fuel product s that are fresh or once -burnt at the start of the cycle.

TSTF-5 64, Rev. 0 Page 5 LCO 3.2.2 is not affected by the proposed change. However, licensees adopting the proposed change will include the MCPR R99.9%R value (i.e., the value equivalent to the current, cycle -dependent SLMCPR) in the COLR values for LCO 3.2.2. TS 5.6.3, "Core Operating Limits Report ,", paragraph a, is revised to require the MCPR R99.9%R value to be in the cycle-specific COLR: a. Core operating limits shall be established prior to each reload cycle, or prior to any remaining portion of a reload cycle, and shall be documented in the COLR for the following: [The individual specifications that address core operating limits must be referenced here. The MCPR R99.9%R value used to calculate the LCO 3.2.2, "MCPR," limit shall be specified in the COLR. ] The proposed change is supported by changes to the TS Bases. The SL 2.1.1.2 Bases and

TS 3.2.2 Bases are revised to reflect the proposed limits for Global Nuclear Fuel and Westinghouse fuel. In sections of the Bases applicable to all fuel types, the existing text and the proposed text are both presented in brackets, signifying that the licensee should choose the applicable description. A reviewer's note is added to the Bases to explain these options. The regulation at 10 CFR 50.50.36, states, "A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications. " A licensee may make changes to the TS Bases without prior NRC staff review and approval in accordance with the Technical Specifications Bases Control Program. The proposed TS Bases changes are consistent with the proposed TS changes and provide the purpose for each requirement in the specification consistent with the Commission's Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 2, 1993 (58 FR 39132). Therefore, the Bases changes are provided for information and approval of the Bases is not requested. A model application is included in the proposed change as Enclosure 1. The model may be used by licensees desiring to adopt the traveler following NRC approval.

3. TECHNICAL EVALUATION The proposed change revises the TS limit for the SLMCPR for the applicable plants and places the existing SLMCPR value (i.e., MCPR R99.9%R) in the COLR. The revised limit calculation method is based on using the Critical Power Ratio (CPR) data statistics and is revised from ensuring that 99.9% of the rods would not be susceptible to transition boiling to ensuring that there is a 95% probability at a 95% confidence level that no rods will be susceptible to transition boiling.

The revised SLMCPR, referred to a s SLMCPR R95/95 R , is based only on the CPR correlation uncertainty determined for the Global Nuclear Fuel or Westinghouse fuel type. Plant and cycle-specific uncertainties are no t included in the SLMCPR R95/95 R. These uncertainties are currently and will continue to be included in the OLMCPR LCO. Reactor coolant flow is one of the uncertainties removed from the SLMCPR calculation and retained in the OLMCPR. Therefore, the SLMCPR for dual recirculation loop operation and single recirculation loop operation are replaced with a single SLMCPR R95/95 R. TSTF-5 64, Rev. 0 Page 6 The LCO 3.2.2 limit s (i.e., the OLMCPR value s) are not changed and will be based on the existing SLMCPR, referred to as MCPR R99.9%R. The OLMCPR will continue to be determined based on the transient CPR component s and the cycle-specific MCPR R99.9% Rvalue that will be included in the COLR. Therefore, the margin to boiling transition remain s unchanged. 3.1. Statistical Treatment of MCPR95/95 For each Global Nuclear Fuel and Westinghouse BWR fuel product (designated i), the MCPR R95/95 R(i) is calculated using that product's experimentally determined critical power statistics as follows: MCPR R95/95 R(i) = µR i R R i R R i R (Eq. 1) Where, µR i R is the mean Experimental Critical Power Ratio (ECPR), R i R is the standard deviation of the ECPRs, and R i R is a statistical parameter chosen to provide 95% probability at 95% confidence (95/95) for the one -sided upper tolerance limit that depends on the number of samples (N R i R) in the critical power database. i is a fuel product line, such as GE14, GNF2, GNF3, OPTIMA2, and OPTIMA3. The statistical parameter, R i R, is calculated using formulas attributed to Mary Gibbons Natrella (1963) as recommended by the National Institute of Standards and Technology (NIST) in their Engineering Statistics Handbook (Reference 3). For a 95/95 probability/confidence level, the R i R values are shown in the table below as a function of database size (N R i R). Table 2: Statistical Parameter, R i R , at (95/95) for the One -Sided Upper Tolerance Limit Database Size, N R i R i 500 1.7625 750 1.7401 1000 1.7270 1250 1.7181 1500 1.7115 2000 1.7024 TSTF-5 64, Rev. 0 Page 7 Assuming a typical critical power database of 1000 data points with no bias (i.e., µR i R = 1.0), the following table illustrates representative MCPR R95/95 R(i) values as a function of the database standard deviation. Table 3: Representative MCPR R95/95 RValues for N R i R=1000 Standard Deviation, R i R (%) MCPR R95/95 2.0 1.03 2.5 1.04 3.0 1.05 3.5 1.06 4.0 1.07 4.5 1.08 5.0 1.09 For cores loaded with a single fuel product, the SLMCPR R95/95 Ris the MCPR R95/95 R(i) value for that particular product line. For cores with a mix of fuel products, the corresponding SLMCPR R95/95 R is based on the largest (i.e., most limiting) of the MCPR R95/95 R(i) values for the product lines that are fresh or once -burnt at the start of the cycle. The MCPR R95/95 R(i) values for product lines that are twice -burnt or more at the start of the cycle may be ignored, as these higher exposure bundles operate with considerable MCPR margin relative to the more limiting fresh and once -burnt bundles. The SLMCPR R95/95 R will be reported in the TS to two digits past the decimal using standard rounding practices. The SLMCPR R95/95 R also serves as the minimum value for the cycle -specific MCPR R99.9%R. The revised method for calculation of the SL for Global Nuclear Fuel and Westinghouse fuel will continue to meet the regulatory definition of a safety limit and to reasonably protect the integrity of the fuel rod cladding against the uncontrolled release of radioactivity. The proposed change is also consistent with equivalent safety limits for other plant designs. 3.2. Cycle-Specific OLMCPR The current MCPR R99.9%R statistical limit calculation will continue to be performed using the approved methodology (e.g., References 4 through 7 or the plant -specific equivalents ) and will be reported in the COLR. The OLMCPR limit in LCO 3.2.2 will continue to be determined TSTF-5 64, Rev. 0 Page 8 based on the transient CPR component and the cycle-specific MCPR R99.9% Rvalue. No changes to the method of determining the OLMCPR (i.e., the LCO 3.2.2 limit) are proposed, and the LCO limits and the MCPR R99.9%R value will be reported in the COLR.

4. REGULATORY EVALUATIO N Title 10 of the Code of Federal Regulations (10 CFR), Part 50, paragraph 50.36(c)(1)(i)(A) states: Safety limits for nuclear reactors are limits upon important process variables that are found to be necessary to reasonably protect the integrity of certain of the physical barriers that guard against the uncontrolled release of radioactivity. If any safety limit is exceeded, the reactor must be shut down. The licensee shall notify the Commission, review the matter, and record the results of the review, including the cause of the condition and the basis for corrective action taken to preclude recurrence. Operation must not be resumed until authorized by the Commission.

The purpose of the MCPR safety limit (SLMCPR) is to protect the physical barrier of the fuel cladding against the uncontrolled release of radioactivity. The SLMCPR is set such that no significant fuel damage is calculated to occur if the limit is met. Although it is recognized that the onset of transition boiling would not necessarily result in damage to BWR fuel rods, the critical power at which boiling transition is calculated to occur has been adopted as a convenient limit. Therefore, the proposed change to the SLMCPR will continue to protect the fuel cladding physical barrier from uncontrolled release of radioactivity. 10 CFR 50, Appendix A, General Design Criteri on 10 states that specified acceptable fuel design limits will not be exceeded during steady state operation, normal operational transients, and Anticipated Operational Occurrences (AOOs). Most plants have a plant -specific design criterion similar to GDC 10. This design criteri on will continue to be met. The OLMCPR, which is not affected by the proposed change, is established to ensure that no fuel damage results during normal operation, normal operational transients, and AOOs. In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the approval of the proposed change will not be inimical to the common defense and security or to the health and safety of the public.

5. REFERENCES
1. Letter from Brian R. Moore, Global Nuclear Fuel, to U.S. NRC, "Information Supporting TSTF-564 Safety Limit Minimum Critical Power Ratio

," June 16, 2017 , ADAMS Accession No. ML17167A108 . 2. Letter from James A. Gresham, Westinghouse Electric Company, to U.S. NRC, "Submittal of 'Calculation for Technical Specification SLM CPR Values Applying to Westinghouse Fuel in Support of TSTF -564'," May 16, 2017, ADAMS Accession No. ML17142A319 . TSTF-5 64, Rev. 0 Page 9 3. NIST/SEMATECH e -Handbook of Statistical Methods, http://www.itl.nist.gov/div898/handbook/ , April 2012.

4. GE Nuclear Energy, "General Electric BWR Thermal Analysis Basis (GETAB): Data, Correlation and Design Application," NEDO-10958-A, January 1977

, ADAMS Accession No. ML102290144 . 5. GE Nuclear Energy, "Power Distribution Uncertainties for Safety Limit MCPR Evaluations," NEDC-32694P-A, August 1999 , ADAMS Accession No. ML003740166 . 6. GE Nuclear Energy, "Methodology and Uncertainties for Safety Limit MCPR Evaluations," NEDC-32601-P-A, August 1999 , ADAMS Accession No. ML003740166 . 7. ABB Combustion Engineering Nuclear Operations, "Reference Safety Report for Boiling Water Reactor Reload Fuel," CENPD -300-P-A, July 1996. ADAMS Accession No. ML110260388.

TSTF-564, Rev. 0 Enclosure 1 Model Application

TSTF-564, Rev. 0 Page 1 [DATE] 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 -0001 DOCKET NO. PLANT NAME 50-[xxx]

SUBJECT:

Application to Revise Technical Specifications to Adopt TSTF-56 4, "Safety Limit MCPR" Pursuant to 10 CFR 50.90, [LICENSEE] is submitting a request for an amendment to the Technical Specifications (TS) for [PLANT NAME, UNIT NOS.]. [LICENSEE] requests adoption of TSTF -56 4 , "Safety Limit MCPR ," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS). The proposed amendment revises the Technical Specification (TS) safety limit (SL) on minimum critical power ratio (MCPR) to reduce the need for cycle-specific changes to the value while still meeting the regulatory requirement for an SL. Attachment 1 provides a description and assessment of the proposed changes. Attachment 2 provides the existing TS pages marked to show the proposed changes. Attachment 3 provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked to show the proposed changes for information only . No regulatory commitments are made in this submittal. Approval of the proposed amendment is requested by [date]. Once approved, the amendment shall be implemented within [ ] days. In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated [STATE] Official. [In accordance with 10 CFR 50.30(b), a license amendment request must be executed in a signed original under oath or affirmation. This can be accomplished by attaching a notarized affidavit confirming the signature authority of the signatory, or by including the following statement in the cover letter: "I declare under penalty of perjury that the foregoing is true and correct. Executed on (date). " The alternative statement is pursuant to 28 USC 1746. It does not require notarization.] If you should have any questions regarding this submittal, please contact [NAME, TELEPHONE NUMBER]. Sincerely, TSTF-564, Rev. 0 Page 2 [Name, Title]

Attachments:

1. Description and Assessment
2. Proposed Technical Specification Changes (Mark

-Up) 3. Revised Technical Specification Pages

4. Proposed Technical Specification Bases Changes (Mark

-Up) for Information Only {Attachments 2, 3, and 4 are not included in the model application and are to be provided by the licensee.} cc: NRC Project Manager NRC Regional Office NRC Resident Inspector State Contact

TSTF-564, Rev. 0 Page 3 ATTACHMENT 1 - DESCRIPTION AND ASSESSMENT

1.0 DESCRIPTION

[LICENSEE] requests adoption of TSTF -564, "Safety Limit MCPR," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS). The proposed amendment revises the Technical Specification (TS) safety limit (SL) on minimum critical power ratio (MCPR) to reduce the need for cycle-specific changes to the value while still meeting the regulatory requirement for an SL. 2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation [LICENSEE] has reviewed the safety evaluation for TSTF -564 provided to the Technical Specifications Task Force in a letter dated [DATE]. This review included a review of the NRC staff's evaluation, as well as the information provided in TSTF -564. [As described herein,] [LICENSEE] has concluded that the justifications presented in TSTF -564 and the safety evaluation prepared by the NRC staff are applicable to [PLANT, UNIT NOS.] and justify this amendment for the incorporation of the changes to the [PLANT] TS. The [PLANT], Unit [1], reactor [is currently][will be] fueled with [TYPE] fuel bundles [describe multiple types of fuel bundles and which type limits the SLMCPR consistent with discussion in the traveler]. Consistent with Table 1 of TSTF -564, the proposed Safety Limit in [SL 2.1.1.2] is [1.07]. The MCPR value calculate d as the point at which 99.9% of the fuel rods would not be susceptible to boiling transition (i.e., reduced heat transfer) during normal operation and anticipated operational occurrences is referred to a s MCPR R99.9%R.R RTechnical Specification 5.6.3, "Core Operating Limits Report (COLR)," is revised to require the MCPR R99.9%R value to be included in the cycle -specific COLR. 2.2 Variations [[LICENSEE] is not proposing any variations from the TS changes described in the TSTF-564 or the applicable parts of the NRC staff's safety evaluation dated [DATE].] [ [LICENSEE] is proposing the following variations from the TS changes described in the TSTF-564 or the applicable parts of the NRC staff's safety evaluation: describe the variations ] [The [PLANT] TS utilize different [numbering][and][titles] than the Standard Technical Specifications on which TSTF-564 was based. Specifically, [describe differences between the plant-specific TS numbering and/or titles and the TSTF-564 numbering and titles.] These differences are administrative and do not affect the applicability of TSTF-564 to the [PLANT] TS.] [The [PLANT] TS contain requirements that differ from the Standard Technical Specifications on which TSTF -564 was based, such as reactor steam dome pressure or core flow in SL 2.1.1.2 , or Applicability in TS 3.2.2, but these differences do not affect the applicability of the TSTF-564 TSTF-564, Rev. 0 Page 4 justification. [For differences other than reactor steam dome pressure , core flow, or applicability, describe the differences and why TSTF -564 is still applicable.] [The traveler and Safety Evaluation discuss the applicable regulatory requirements and guidance, including the 10 CFR 50, Appendix A, General Design Criteria (GDC). [PLANT] was not licensed to the 10 CFR 50, Appendix A, GDC. The [PLANT] equivalents of the referenced GDC are [reference including UFSAR location, if applicable]. [Discuss the equivalence of the referenced plant -specific requirements to the Appendix A GDC as related to the proposed change.] This difference does not alter the conclusion that the proposed change is applicable to [PLANT].]

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis [LICENSEE] requests adoption of TSTF -564, "Safety Limit MCPR," which is an approved change to the Improved Standard Technical Specifications (ISTS), into the [PLANT NAME, UNIT NOS] Technical Specifications (TS). The proposed change revises the Technical Specification (TS) safety limit on minimum critical power ratio (SLMCPR). The revised limit calculation method is based on using the Critical Power Ratio (CPR) data statistics and is revised from ensuring that 99.9% of the rods would not be susceptible to transition boiling to ensuring that there is a 95% probability at a 95% confidence level that no rods will be susceptible to transition boiling. A single SLMCPR value will be used instead of two values applicable when one or two recirculation loops are in operation. TS 5.6.3, "Core Operating Limits Report (COLR)," is revised to require the current SLMCPR value to be included in the COLR. [LICENSEE] has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed amendment revises the TS SLMCPR and the list of core operating limits to be included in the Core Operating Limits Report (COLR). The SLMCPR is not an initiator of any accident previously evaluated. The revised safety limit values continue to ensure for all accidents previously evaluated that the fuel cladding will be protected from failure due to transition boiling. The proposed change does not affect plant operation or any procedural or administrative controls on plant operation that affect the functions of preventing or mitigating any accidents previously evaluated. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

TSTF-564, Rev. 0 Page 5 2. Does the proposed amendment create the possibility of a new or different kind of accident from any previously evaluated? Response: No The proposed amendment revises the T S SLMCPR and the list of core operating limits to be included in the COLR. The proposed change will not affect the design function or operation of any structures, systems or components (SSCs). No new equipment will be installed. As a result, the proposed change will not create any credible new failure mechanisms, malfunctions, or accident initiators not considered in the design and licensing bases. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No The proposed amendment revises the TS SLMCPR and the list of core operating limits to be included in the COLR. This will result in a change to a safety limit, but will not result in a significant reduction in the margin of safety provided by the safety limit. As discussed in the application, changing the SLMCPR methodology to one based on a 95% probability with 95% confidence that no fuel rods experience boiling transition during an anticipated transient instead of the current limit based on ensuring that 99.9% of the fuel rods are not susceptible to transition boiling does not have a significant effect on plant response to any analyzed accident. The SLMCPR and the TS Limiting Condition for Operation (LCO) on MCPR continue to provide the same level of assurance as the current limits and does not reduce a margin of safety. Therefore, the proposed change does not involve a significant reduction in a margin of safety. Based on the above, [LICENSEE] concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration " is justified. 3.2 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

TSTF-564, Rev. 0 Page 6 4.0 ENVIRONMENTAL EVALUATION The proposed change would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent s that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.

TSTF-564, Rev. 0 Enclosure 2 Technical Specifications Proposed Changes

[]

REVIEWER'S NOTE ------------------------------

In the Background and Applicable Safety Analysis sections, select the SLMCPR 95/95 discussion or the 99.9% of the fuel rods discussion as the applicable SL 2.1.1.2 basis. ----------------------------------------------------------------------------------------------

[This is accomplished by having a Safety Limit Minimum Critical Power Ratio (SLMCPR) design basis, referred to as SLMCPR 95/95, which corresponds to a 95% probability at a 95% confidence level (the 95/95 MCPR criterion) that transition boiling will not occur.] [are not susceptible to boiling transition ]

[The Tech Spec SL is set generically on a fuel product MCPR correlation basis as the MCPR which corresponds to a 95% probability at a 95% confidence level that transition boiling will not occur, referred to as SLMCPR 95/95] [ ]

and Westinghouse [The Technical Specification SL value is dependent on the fuel product line and the corresponding MCPR correlation, which is cycle independent. The value is based on the Critical Power Ratio (CPR) data statistics and a 95% probability with 95% confidence that rods are not susceptible to boiling transition, referred to as MCPR 95/95.]

Reviewer's Note --------------------------------

The MCPR 95/95 Values by Vendor and Fuel Product Type: Vendor Fuel Type MCPR 95/95 Global Nuclear Fuel GE14 1.05 Global Nuclear Fuel GNF2 1.07 Global Nuclear Fuel GNF3 1.07 WestinghouseOptima2 1.06 WestinghouseOptima3 1.06 ------------------------------------------------------------------------------------------------

[For cores with a single fuel product line, the SLMCPR 95/95 is the MCPR 95/95 for the fuel type. For cores loaded with a mix of applicable fuel types, the SLMCPR 95/95 is based on the largest (i.e., most limiting) of the MCPR values for the fuel product lines that are fresh or once-burnt at the start of the cycle.]

[

]

, and that 99.9% of the fuel rods are not susceptible to boiling transition if the limit is not violated

REVIEWER'S NOTE ------------------------------- Incorporate the MCPR 95/95 discussion if applicable. -----------------------------------------------------------------------------------------------Safety Limit ()combined with [SL][99.9%]

[MCPR 99.9% is determined to ensure more than 99.9% of the fuel rods in the core are not susceptible to boiling transition using a statistical model that combines all the uncertainties in operating parameters and the procedures used to calculate critical power. The probability of the occurrence of boiling transition is determined using the approved Critical

Power correlations. Details of the MCPR 99.9% calculation are given in Reference 2. Reference 2 also includes a tabulation of the uncertainties and the nominal values of the parameters used in the MCPR 99.9% statistical analysis.] are [the MCPR 99.9% value and] , and

by approved transient analysis models

[(MCPR99.9% value, MCPR f values, and MCPR p values)] [, which are based on the MCPR 99.9% limit specified in the COLR] [99.9%]

[]

The MCPR 99.9% value used to calculate the LCO 3.2.2, "MCPR," limit shall be specified in the COLR.

REVIEWER'S NOTE ------------------------------

In the Background and Applicable Safety Analysis sections, select the SLMCPR 95/95 discussion or the 99.9% of the fuel rods discussion as the applicable SL 2.1.1.2 basis. ----------------------------------------------------------------------------------------------

[This is accomplished by having a Safety Limit Minimum Critical Power Ratio (SLMCPR) design basis, referred to as SLMCPR 95/95, which corresponds to a 95% probability at a 95% confidence level (the 95/95 MCPR criterion) that transition boiling will not occur.] [are not susceptible to boiling transition]

[The Tech Spec SL is set generically on a fuel product MCPR correlation basis as the MCPR which corresponds to a 95% probability at a 95% confidence level that transition boiling will not occur, referred to as SLMCPR 95/95.] [

]

and Westinghouse

[The Technical Specification SL value is dependent on the fuel product line and the corresponding MCPR correlation, which is cycle independent. The value is based on the Critical Power Ratio (CPR) data statistics and a 95% probability with 95% confidence that rods will not go into boiling transition, referred to as MCPR 95/95.] -------------------------------------- Reviewer's Note -------------------------------- The MCPR 95/95 Values by Vendor and Fuel Product Type: Vendor Fuel Type MCPR 95/95 Global Nuclear Fuel GE14 1.05 Global Nuclear Fuel GNF2 1.07 Global Nuclear Fuel GNF3 1.07 WestinghouseOptima2 1.06 WestinghouseOptima3 1.06 ------------------------------------------------------------------------------------------------ [For cores with a single fuel product line, the SLMCPR 95/95 is the MCPR 95/95 for the fuel type. For cores loaded with a mix of applicable fuel types, the SLMCPR 95/95 is based on the largest (i.e., most limiting) of the MCPR values for the fuel product lines that are fresh or once-burnt at the start of the cycle.]

[

]

, and that 99.9% of the fuel rods are not susceptible to boiling transition if the limit is not violated

REVIEWER'S NOTE ------------------------------- Incorporate the MCPR 95/95 discussion if applicable. ------------------------------------------------------------------------------------------------

Safety Limit ()combined with [SL][99.9%] [MCPR 99.9% is determined to ensure more than 99.9% of the fuel rods in the core are not susceptible to boiling transition using a statistical model that combines all the uncertainties in operating parameters and the procedures used to calculate critical power. The probability of the occurrence of boiling transition is determined using the approved Critical

Power correlations. Details of the MCPR 99.9% calculation are given in Reference 2. Reference 2 also includes a tabulation of the uncertainties and the nominal values of the parameters used in the MCPR 99.9% statistical analysis.] are [the MCPR 99.9% value and] , and

approved transient analysis models

[(MCPR99.9% value, MCPR f values, and MCPR p values)] [, which are based on the MCPR 99.9% limit specified in the COLR]

[99.9%]}}

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