Text

Technical Specifications and 10 CFR 50.12 Exemption Request to Implement Optimized ZIRLO Fuel Rod Cladding (WBN-TS-18-11)
	ML18205A492
Person / Time
Site:	Watts Bar
Issue date:	07/23/2018
From:	Henderson E; Tennessee Valley Authority
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	CNL-18-086
	Download: ML18205A492 (34)
	v • d • e

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-18-086 July 23, 2018 10 CFR 50.90 10 CFR 50.12 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant Units 1 and 2 Facility Operating License Nos. NPF-90 and NPF-96 Docket Nos. 50-390 and 50-391

Subject:

Application to Revise Watts Bar Nuclear Plant Units 1 and 2 Technical Specifications and 10 CFR 50.12 Exemption Request to Implement Optimized ZIRLO' Fuel Rod Cladding (WBN-TS-18-11)

References:

1.

NRC letter to Westinghouse, "Final Safety Evaluation for Addendum 1 to Topical Report WCAP-12610-P-A and CENPD-404-P-A, 'Optimized ZIRLO', dated June 10, 2005 (ML051670403)

2.

Westinghouse letter to NRC, LTR-NRC-06-45, Issuance of Approved Version of WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A (Proprietary)/WCAP-14342-A & CENPD-404-NP-A, Addendum 1-A (Non-Proprietary) Optimized ZIRLO', dated July 10, 2006 (ML062080563)

3.

WCAP-14432-A and CENPD-404-NP-A, Addendum 1-A, "Optimized ZIRLO'," July 2006 (ML062080569)

In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR) 50.90, "Application for amendment of license, construction permit, or early site permit," Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN),

Units 1 and 2, respectively.

The proposed amendment (Enclosure 1) would modify the WBN Units 1 and 2 Technical Specifications (TS) 4.2.1, Fuel Assemblies, and 5.9.5, Core Operating Limits Report (COLR), to allow the use of Optimized ZIRLO'1 as an approved fuel rod cladding material.

1 Optimized ZIRLO is a trademark of Westinghouse Electric Company LLC

U.S. Nuclear Regulatory Commission CNL-18-086 Page 2 July 23, 2018 This change is consistent with the Nuclear Regulatory Commission (NRC) safety evaluation that approved the use of Optimized ZIRLO fuel rod cladding material (Reference 1) as documented in WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A (Proprietary)

(Reference 2) and WCAP-14342-A and CENPD-404-NP-A (Non-Proprietary) (Reference 3).

In support of this license amendment request, Enclosure 2 contains an exemption request in accordance with 10 CFR 50.12, "Specific exemptions, from certain requirements of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors," and 10 CFR 50, Appendix K, "ECCS Evaluation Models." This exemption request relates solely to the specific type of cladding material specified in these regulations for use in light water reactors. As written, the regulations presume use of either Zircaloy or ZIRLO2 fuel rod cladding. The exemption is required because Optimized ZIRLO has a slightly different composition than Zircaloy or ZIRLO.

provides a description and technical evaluation of the proposed change, a regulatory evaluation, and a discussion of environmental considerations. Attachments 1 and 2 to Enclosure 1 provide the existing respective WBN Unit 1 and Unit 2 TS pages marked up to show the proposed changes. Attachments 3 and 4 to Enclosure 1 provide the revised (clean) respective WBN Unit 1 and Unit 2 TS pages.

The WBN Plant Operations Review Committee has determined that operation of WBN Units 1 and 2 in accordance with the proposed change will not endanger the health and safety of the public.

TVA has determined that there are no significant hazard considerations associated with the proposed change and that the change qualifies for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). Additionally, in accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and the enclosures to the Tennessee Department of Environment and Conservation.

TVA requests approval of the proposed license amendment and exemption request within one year from the date of this letter with implementation within 30 days following NRC approval to support planning activities for the WBN Unit 2 Fall 2020 Refueling Outage (U2R3) and the WBN Unit 1 Fall 2021 Refueling Outage (U1R17).

There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to Edward D. Schrull at (423) 751-3850.

2 ZIRLO is a registered trademark of Westinghouse Electric Company LLC

U.S. Nuclear Regulatory Commission CNL-18-086 Page 3 July 23, 2018 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 23rd day of July 2018.

Erin K. Henderson Director, Nuclear Regulatory Affairs

Enclosures:

1. Evaluation of Proposed Change

2. Exemption Request cc (Enclosures):

NRC Regional Administrator-Region II NRC Project Manager - Watts Bar Nuclear Plant NRC Senior Resident Inspector - Watts Bar Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation CNL-18-086 E1-1 of 14 Evaluation of Proposed Change

Subject:

Application to Revise Watts Bar Nuclear Plant Units 1 and 2 Technical Specifications and 10 CFR 50.12 Exemption Request to Implement Optimized ZIRLO' Fuel Rod Cladding (WBN-TS-18-11)

Contents 1.0

SUMMARY

DESCRIPTION............................................................................................. 2 2.0 DETAILED DESCRIPTION.............................................................................................. 2 2.1 Reason for the Proposed Change................................................................................ 2 2.2 Description of the Proposed Changes.......................................................................... 3

3.0 TECHNICAL EVALUATION

............................................................................................. 3 3.1 Review of Condition in the NRC Safety Evaluation...................................................... 3 3.2 Effect of Optimized ZIRLO on WBN Specific Licensing Actions................................... 7

4.0 REGULATORY EVALUATION

........................................................................................ 8 4.1 Applicable Regulatory Requirements and Criteria........................................................ 8 4.1.1 Regulations and Regulatory Guidance.................................................................. 8 4.1.2 General Design Criteria........................................................................................ 9 4.2 Precedent...................................................................................................................10 4.3 Significant Hazards Consideration..............................................................................11 4.4 Conclusion..................................................................................................................12

5.0 ENVIRONMENTAL CONSIDERATION

..........................................................................12

6.0 REFERENCES

...............................................................................................................13 Attachments

1. Proposed TS Changes (Mark-Ups) for WBN Unit 1

2. Proposed TS Changes (Mark-Ups) for WBN Unit 2

3. Proposed TS Changes (Final Typed) for WBN Unit 1

4. Proposed TS Changes (Final Typed) for WBN Unit 2 CNL-18-086 E1-2 of 14 1.0

SUMMARY

DESCRIPTION Pursuant to Title 10 of the Code of Federal Regulations (CFR) §50.90, Tennessee Valley Authority (TVA) is submitting a request for a change to Facility Operating License (OL) Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2, respectively.

Specifically, TVA is requesting a license amendment to revise the WBN Units 1and 2 Technical Specification (TS) 4.2.1, Fuel Assemblies, to allow the use of Optimized ZIRLO'1 fuel rod cladding material. The proposed license amendment request (LAR) also revises WBN Units 1and 2 TS 5.9.5, Core Operating Limits Report (COLR), to add Westinghouse Electric Company LLC (Westinghouse) topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'," (Reference 1) to the list of analytical methods used to determine the core operating limits approved by the Nuclear Regulatory Commission (NRC). Other editorial changes are to correct the spelling of the word Zircaloy (WBN Unit 1 TS 4.2.1 only), add the word "clad" after the proposed phrase "Optimized ZIRLO'," capitalize the word Zirlo, and add a registered trademark designator to the word ZIRLO.

Additionally, in support of this LAR, Enclosure 2 contains an exemption request from the provisions of 10 CFR 50.46, "Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors," and 10 CFR 50, Appendix K, "ECCS Evaluation Models."

Optimized ZIRLO was developed to meet the needs of longer operating cycles with increased fuel discharge burnup and fuel duty. Fuel rod internal pressure (resulting from the increased fuel duty, use of integral fuel burnable absorbers, and corrosion and temperature feedback effects) has become more limiting with respect to fuel rod design criteria. Reducing the associated corrosion buildup and thus minimizing temperature feedback effects provides additional margin to the fuel rod internal pressure design criterion. Compared to ZIRLO2, the lower tin content and microstructure difference of Optimized ZIRLO provides a reduced corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from abnormal chemistry conditions.

TVA currently plans to install Optimized ZIRLO clad fuel rods during the WBN Unit 2 Fall 2020 Refueling Outage (U2R3) and the WBN Unit 1 Fall 2021 Refueling Outage (U1R17).

2.0 DETAILED DESCRIPTION 2.1 REASON FOR THE PROPOSED CHANGE The proposed change allows the use of Optimized ZIRLO fuel rod cladding material in support of the WBN Unit 2 Fall 2020 Refueling Outage (U2R3) and the WBN Unit 1 Fall 2021 Refueling Outage (U1R17). Optimized ZIRLO provides a reduced corrosion rate while maintaining the benefits of mechanical strength and resistance to accelerated corrosion from abnormal chemistry conditions.

1 Optimized ZIRLO is a trademark of Westinghouse Electric Company LLC 2 ZIRLO is a registered trademark of Westinghouse Electric Company LLC CNL-18-086 E1-3 of 14

2.2 DESCRIPTION

OF THE PROPOSED CHANGES The following is a detailed description of the proposed WBN Units 1 and 2 TS changes.

WBN Unit 1 TS 4.2.1, Fuel Assemblies, is revised to add Optimized ZIRLO',

correct the spelling of the word Zircaloy, add the word "clad" after the proposed phrase "Optimized ZIRLO'," capitalize the word Zirlo, and add a registered trademark designator to the word ZIRLO as follows:

o The requirement that Each assembly shall consist of a matrix of Zircalloy or Zirlo fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material is revised to state, Each assembly shall consist of a matrix of Zircaloy, or ZIRLO, or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material.

WBN Unit 2 TS 4.2.1,Fuel Assemblies, is revised to add Optimized ZIRLO', add the word "clad" after the proposed phrase "Optimized ZIRLO'," capitalize the word Zirlo, and add a registered trademark designator to the word ZIRLO as follows:

o The requirement that Each assembly shall consist of a matrix of Zirlo fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material is revised to state, Each assembly shall consist of a matrix of ZIRLO or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material.

WBN Units 1 and 2 TS 5.9.5, CORE OPERATING LIMITS REPORT (COLR), are revised to add Westinghouse topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'" to the list of analytical methods as follows:

10.

WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'.

Attachments 1 and 2 to this enclosure provide the existing respective WBN Unit 1 and Unit 2 TS pages marked up to show the proposed changes. Attachments 3 and 4 to this enclosure provide the revised (clean) respective WBN Unit 1 and Unit 2 TS pages.

3.0 TECHNICAL EVALUATION

3.1 REVIEW OF CONDITION IN THE NRC SAFETY EVALUATION Reference 1 provides the details and test results of Optimized ZIRLO compared to ZIRLO fuel rod cladding material. Reference 2 is the non-proprietary version of Reference 1. Reference 1 also contains the material properties to be used in various models and methodologies when analyzing Optimized ZIRLO fuel rod cladding. The NRC safety evaluation (SE) for Reference 1 (Reference 3) contains 10 conditions and limitations that are addressed below:

NRC Condition 1 Until rulemaking to 10 CFR Part 50 addressing Optimized ZIRLO has been completed, implementation of Optimized ZIRLO fuel clad requires an exemption from 10 CFR 50.46 and 10 CFR Part 50, Appendix K.

CNL-18-086 E1-4 of 14 TVA Response A request for the required exemption from 10 CFR 50.46 and 10 CFR 50, Appendix K is provided in Enclosure 2.

NRC Condition 2 The fuel rod burnup limit for this approval remains at currently established limits:

62 gigawatt days per metric tonne of uranium (GWd/MTU) for Westinghouse fuel designs and 60 GWd/MTU for Combustion Engineering (CE) fuel designs.

TVA Response For any fuel using Optimized ZIRLO fuel rod cladding, the maximum fuel rod burnup limit for Westinghouse fuel designs will continue to be 62 GWd/MTU until such time that a new fuel rod burnup limit is approved for use. WBN Units 1 and 2 use Westinghouse fuel designs. The fuel burnup limit will be confirmed as part of the normal reload design process.

NRC Condition 3 The maximum fuel rod waterside corrosion, as predicted by the best-estimate model, will

[satisfy proprietary limits (included in the topical report and proprietary version of the NRC SE)] of hydrides for all locations of the fuel rod.

TVA Response The maximum fuel rod waterside corrosion for fuel using Optimized ZIRLO fuel rod cladding will be confirmed to be less than the specified proprietary limits for all locations of the fuel rod. Evaluations will be performed to confirm that the appropriate corrosion limits are satisfied as part of the normal reload design process.

NRC Condition 4 All the conditions listed in previous NRC SE approvals for methodologies used for standard ZIRLO and Zircaloy-4 fuel analysis will continue to be met, except that the use of Optimized ZIRLO cladding in addition to standard ZIRLO and Zircaloy-4 cladding is now approved.

TVA Response The Optimized ZIRLO fuel rod analysis will continue to meet all conditions associated with approved methods. Confirmation of these conditions is required as part of the normal reload design process.

NRC Condition 5 All methodologies will be used only within the range for which ZIRLO and Optimized ZIRLO data were acceptable and for which the verifications discussed in Addendum 1 and responses to requests for additional information (RAl) were performed.

CNL-18-086 E1-5 of 14 TVA Response The application of ZIRLO and Optimized ZIRLO in approved methodologies will be made consistent with the approach accepted in Reference 1. Confirmation of these conditions is required as part of the normal reload design process.

NRC Condition 6 The licensee is required to ensure that Westinghouse has fulfilled the following commitment: Westinghouse shall provide the NRC staff with a letter(s) containing the following information (based on the schedule described in response to RAI 3 of Reference 4):

a. Optimized ZIRLO lead test assembly (LTA) data from Byron, Calvert Cliffs, Catawba, and Millstone.

i.

Visual ii. Oxidation of fuel rods iii. Profilometry iv. Fuel rod length

v. Fuel assembly length

b. Using the standard and Optimized ZIRLO database including the most recent LTA data, confirm applicability with currently approved fuel performance models (e.g., measured versus predicted).

Confirmation of the approved models' applicability up through the projected end of cycle burnup for the Optimized ZIRLO fuel rods must be completed prior to their initial batch loading and prior to the startup of subsequent cycles. For example, prior to the first batch application of Optimized ZIRLO, sufficient LTA data may only be available to confirm the models' applicability up through 45 GWd/MTU. In this example, the licensee would need to confirm the models up through the end of the initial cycle. Subsequently, the licensee would need to confirm the models, based upon the latest LTA data, prior to re-inserting the Optimized ZIRLO fuel rods in future cycles. Based upon the LTA schedule, it is expected that this issue may only be applicable to the first few batch implementations, since sufficient LTA data up through the burnup limit should be available within a few years.

TVA Response Westinghouse has provided the NRC with information related to test data and models.

As a result, the NRC has confirmed that this condition has been satisfied as stated in Reference 5. No further information is necessary in response to this condition.

CNL-18-086 E1-6 of 14 NRC Condition 7 The licensee is required to ensure that Westinghouse has fulfilled the following commitment: Westinghouse shall provide the NRC staff with a letter containing the following information (based on the schedule in response to RAI 11 of Reference 4):

a. Vogtle growth and creep data summary reports.

b. Using the standard ZIRLO and Optimized ZIRLO database including the most recent Vogtle data, confirm applicability with currently approved fuel performance models (e.g., level of conservatism in Westinghouse rod pressure analysis, measured versus predicted, predicted minus measured versus tensile and compressive stress).

Confirmation of the approved models' applicability up through the projected end of cycle burnup for the Optimized ZIRLO fuel rods must be completed prior to their initial batch loading and prior to the startup of subsequent cycles. For example, prior to the first batch application of Optimized ZIRLO, sufficient LTA data may only be available to confirm the models' applicability up through 45 GWd/MTU. In this example, the licensee would need to confirm the models up through the end of the initial cycle. Subsequently, the licensee would need to confirm the models, based upon the latest LTA data, prior to re-inserting the Optimized ZIRLO fuel rods in future cycles. Based upon the LTA schedule, it is expected that this issue may only be applicable to the first few batch implementations since sufficient LTA data up through the burnup limit should be available within a few years.

TVA Response Westinghouse has provided the NRC with information related to test data and models.

As a result, the NRC has confirmed that this condition has been satisfied as stated in Reference 5. No further information is necessary in response to this condition.

NRC Condition 8 The licensee shall account for the relative differences in unirradiated strength (yield strength (YS) and ultimate tensile strength (UTS) between Optimized ZIRLO and standard ZIRLO in cladding and structural analyses until irradiated data for Optimized ZIRLO has been collected and provided to the NRC staff.

a. For the Westinghouse fuel design analyses:

i.

The measured, unirradiated Optimized ZIRLO strengths shall be used for beginning of life (BOL) analyses.

ii.

Between BOL up to a radiation fluence of 3.0E21 neutrons/centimeter2 (n/cm2)

[E > 1 (million electron volts (MeV)], pseudo-irradiated Optimized ZIRLO strength set equal to linear interpolation between the following two strength level points: at zero fluence, strength of Optimized ZIRLO equal to measured strength of Optimized ZIRLO and at a fluence of 3.0E21 n/cm2 (E > 1 MeV), irradiated strength of standard ZIRLO at the fluence of 3.0E21 n/cm2 (E > 1 MeV) minus 3 kilopound per square inch (ksi).

CNL-18-086 E1-7 of 14 iii.

During subsequent irradiation from 3.0E21 n/cm2 up to 12E21 n/cm2, the differences in strength (the difference at a fluence of 3.0E21 n/cm2 due to tin content) shall be decreased linearly such that the pseudoirradiated Optimized ZIRLO strengths will saturate at the same properties as standard ZIRLO at 12.0E21 n/cm2

b. For the CE fuel design analyses, the measured, unirradiated Optimized ZIRLO strengths shall be used for all fluence levels (consistent with previously approved methods).

TVA Response The Optimized ZIRLO fuel rod analysis for WBN will use the yield strength and ultimate tensile strength as modified per conditions and limitations 8.a.i., 8.a.ii., and 8.a.iii.

Confirmation of this condition is required as part of the reload design process.

Condition 8.b does not apply because WBN uses a Westinghouse fuel design and not a CE fuel design.

NRC Condition 9 As discussed in response to RAI 21 of Reference 4, for plants introducing Optimized ZIRLO that are licensed with LOCBART or STRIKIN-11 and have a limiting peak cladding temperature (PCT) that occurs during blowdown or early reflood, the limiting LOCBART or STRIKIN-11 calculation will be rerun using the specified Optimized ZIRLO material properties. Although not a condition of approval, the NRC strongly recommends that, for future evaluations, Westinghouse update all computer models with Optimized ZIRLO specific material properties.

TVA Response Condition 9 does not apply because WBN is not licensed to use the LOCBART or STRIKIN-11 codes.

NRC Condition 10 Due to the absence of high temperature oxidation data for Optimized ZIRLO, the Westinghouse coolability limit on PCT during the locked rotor event shall be [proprietary limits included in topical report and proprietary version of safety evaluation].

TVA Response Confirmation of this condition is required as part of the normal reload design process.

3.2 EFFECT OF OPTIMIZED ZIRLO ON WBN SPECIFIC LICENSING ACTIONS In Reference 6, TVA submitted an LAR for WBN Unit 2 to revise WBN Unit 2 Operating License Condition 2.C(4) to permit the use of the Fuel Rod Performance and Design 4 Thermal Conductivity Degradation (PAD4TCD) computer program to continue to establish core operating limits until the WBN Unit 2 steam generators (SGs) are replaced with SGs equivalent to those in WBN Unit 1. In Reference 7, TVA provided a supplement to Reference 6 that addressed the effects of TCD on the non-loss of coolant CNL-18-086 E1-8 of 14 accidents (LOCA) WBN dual-unit updated final safety analysis report (UFSAR)

Chapter 15 accidents. The use of Optimized ZIRLO is bounded by the analyses that support this request and therefore is considered independent of this licensing action.

WBN Unit 1 is currently licensed to use Tritium Producing Burnable Absorber Rods (TPBARs) in the WBN Unit 1 reactor core. In Reference 8, TVA submitted an LAR to authorize the use of TPBARs in the WBN Unit 2 reactor core. Supplements to Reference 8 were submitted to the NRC in References 9 and 10. Optimized ZIRLO is not used as the cladding material for TPBARs. The use of Optimized ZIRLO is bounded by the analyses supporting this change and therefore is considered independent of this licensing action.

4.0 REGULATORY EVALUATION

4.1 APPLICABLE REGULATORY REQUIREMENTS AND CRITERIA Title 10 of the Code of Federal Regulations (10 CFR) Part 50.36, Technical Specifications, requires that the TS include limiting conditions for operation, which are the lowest functional capability or performance levels of equipment required for safe Operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TS until the condition can be met.

4.1.1 Regulations and Regulatory Guidance NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition" (SRP), Section 4.2, "Fuel System Design," provides regulatory guidance to the NRC staff for the review of fuel rod cladding materials and fuel system. In addition, the SRP provides guidance for compliance with the applicable General Design Criteria (GDC) of 10 CFR Part 50, Appendix A. According to SRP Section 4.2, the fuel system safety review provides assurance that:

The fuel system is not damaged as a result of normal operation and anticipated operational occurrences (AOOs).

Fuel system damage is never so severe as to prevent control rod insertion when it is required.

The number of fuel rod failures is not underestimated for postulated accidents.

Coolability is always maintained.

In Reference 3, the NRC approved Addendum 1 to WCAP-12610-P-A and CENPD-404-P-A for the use of Optimized ZIRLO as an acceptable fuel rod cladding material for Westinghouse fuel designs.

10 CFR 50.46 requires, in part, that each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide pellets within cylindrical Zircaloy or ZIRLO cladding must be provided with an emergency core cooling system (ECCS) that must be designed so that its calculated cooling performance following postulated loss-of-coolant accidents conforms to the criteria set forth in 10 CFR 50.46(b). Appendix K to 10 CFR Part 50 establishes the regulations for conservative ECCS evaluation models. contains an exemption request from 10 CFR 50.46 and Appendix K to 10 CFR Part 50.

CNL-18-086 E1-9 of 14 4.1.2 General Design Criteria As noted in the WBN dual-unit updated final safety analysis report (UFSAR)

Section 3.1.1, WBN was designed to meet the intent of the "Proposed General Design Criteria for Nuclear Power Plant Construction Permits" published in July 1967. The WBN construction permit was issued in January 1973. The WBN Unit 2 UFSAR, however, addresses the NRC GDC published as Appendix A to 10 CFR 50 in July 1971, including Criterion 4 as amended October 27, 1987.

The WBN UFSAR contains these GDC followed by a discussion of the design features and procedures that meet the intent of the criteria. The relevant GDC are described below.

Criterion 10 - Reactor Design The reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.

Compliance with GDC 10 is described in Section 3.1.2.2 of the WBN dual-unit UFSAR.

Criterion 27 - Combined Reactivity Control System Capability The reactivity control systems shall be designed to have a combined capability in conjunction with poison addition by the ECCS of reliably controlling reactivity changes to assure that under postulated accident conditions and with appropriate margin for stuck rods, the capability to cool the core is maintained.

Compliance with GDC 27 is described in Section 3.1.2.3 of the WBN dual-unit UFSAR.

Criterion 35 - Emergency Core Cooling A system to provide abundant emergency core cooling shall be provided. The system safety function shall be to transfer heat from the reactor core following any loss of reactor coolant at a rate such that (1) fuel and clad damage that could interfere with continued effective core cooling is prevented and (2) clad metal-water reaction is limited to negligible amounts.

Suitable redundancy in components and features, and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.

Compliance with GDC 35 is described in Section 3.1.2.4 of the WBN dual-unit UFSAR.

There will be no changes to the WBN design such that compliance with any of the regulatory requirements above would come into question. As such, WBN Units 1 and 2 will continue to comply with the applicable regulatory requirements.

CNL-18-086 E1-10 of 14 4.2 PRECEDENT This LAR is similar in nature to the following LARs and exemption requests approved by the NRC that authorized the use of Optimized ZIRLO fuel rod cladding:

Beaver Valley Power Station, Units 1 and 2 (References 11 and 12)

Palo Verde Nuclear Generating Station, Units 1, 2, and 3 (References 13 and 14)

Wolf Creek Generating Station (References 15 and 16)

Seabrook Station, Unit 1 (References 17 and 18)

R.E. Ginna Nuclear Power Plant (References 19 and 20)

TVA also reviewed the related RAI responses associated with the Palo Verde Nuclear Generating Station, Units 1, 2, and 3 LAR (Reference 21) and the Wolf Creek Generating Station LAR (Reference 22) and incorporated the requested information as appropriate.

CNL-18-086 E1-11 of 14 4.3 SIGNIFICANT HAZARDS CONSIDERATION The Tennessee Valley Authority (TVA) proposes to revise the Watts Bar Nuclear Plant (WBN) Units 1 and 2 Technical Specifications (TS) to allow the use of Optimized ZIRLO'1 fuel rod cladding material. The current acceptable fuel rod cladding material is identified in WBN Units 1 and 2 TS 4.2.1, "Fuel Assemblies.

The proposed amendment would revise WBN Units 1 and 2 TS 4.2.1 to add Optimized ZIRLO to the approved fuel rod cladding materials. The proposed amendment also revises WBN Units 1and 2 TS 5.9.5, Core Operating Limits Report (COLR), to add Westinghouse Electric Company LLC (Westinghouse) topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'," to the list of analytical methods used to determine the core operating limits reviewed and approved by the Nuclear Regulatory Commission (NRC). Other editorial changes are to correct the spelling of the word Zircaloy (WBN Unit 1 TS 4.2.1 only), add the word "clad" after the proposed phrase "Optimized ZIRLO'," capitalize the word Zirlo, and add a registered trademark designator to the word ZIRLO.

TVA 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 consequence of an accident previously evaluated?

Response: No The proposed amendment will allow the use of Optimized ZIRLO clad nuclear fuel at WBN Units 1 and 2. The NRC approved topical report WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, which addresses Optimized ZIRLO fuel rod cladding and demonstrates that Optimized ZIRLO fuel rod cladding has essentially the same properties as currently licensed ZIRLO2 fuel rod cladding. The use of Optimized ZIRLO fuel rod cladding material will not result in adverse changes to the operation or configuration of the facility. The fuel cladding itself is not an accident initiator and does not affect accident probability. Use of Optimized ZIRLO meets the fuel design acceptance criteria and hence does not significantly affect the consequences of an accident.

Therefore, the proposed TS change does not result in a significant increase in the probability or consequences of an accident previously evaluated within the WBN Unit 2 UFSAR.

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The use of Optimized ZIRLO fuel rod cladding material will not result in adverse 1 Optimized ZIRLO is a trademark of Westinghouse Electric Company LLC 2 ZIRLO is a registered trademark of Westinghouse Electric Company LLC CNL-18-086 E1-12 of 14 changes to the operation or configuration of the facility. WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A demonstrated that the material properties of Optimized ZIRLO fuel rod cladding are similar to those of ZIRLO fuel rod cladding.

Therefore, Optimized ZIRLO fuel rod cladding will perform similarly to ZIRLO fuel rod cladding, thus precluding the possibility of the fuel rod cladding becoming an accident initiator and causing a new or different kind of accident.

Therefore, the proposed TS change does not create the possibility of a new or different kind of accident from any accident previously evaluated is not created.

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

Response: No.

WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, demonstrated that the material properties of the Optimized ZIRLO fuel rod cladding are similar to those of ZIRLO fuel rod cladding. Optimized ZIRLO fuel rod cladding is expected to perform similarly to ZIRLO fuel rod cladding for normal operating and accident scenarios, including both loss-of-coolant accident (LOCA) and non-LOCA scenarios. The use of Optimized ZIRLO fuel rod cladding will not result in adverse changes to the operation or configuration of the facility.

Therefore, the proposed TS change does not a significant reduction in a margin of safety.

Based on the above, TVA concludes that the proposed amendment does not involve a 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.

4.4 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 Commissions 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.

5.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment 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 amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment 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 amendment.

CNL-18-086 E1-13 of 14

6.0 REFERENCES

1. Westinghouse letter to NRC, LTR-NRC-06-45, Issuance of Approved Version of WCAP-12610-P-A & CENPD-404-P-A, Addendum I-A (Proprietary)/WCAP-14342-A

& CENPD-404-NP-A, Addendum 1-A (Non-Proprietary) Optimized ZIRLOTM, dated July 10, 2006 (ML062080563)

2. WCAP-14432-A & CENPD-404-NP-A, Addendum 1-A, "Optimized ZIRLO',"

July 2006 (ML062080569)

3. NRC letter to Westinghouse, "Final Safety Evaluation for Addendum 1 to Topical Report WCAP-12610-P-A & CENPD-404-P-A, 'Optimized ZIRLO', dated June 10, 2005 (ML051670403)

4. Westinghouse letter to NRC, LTR-NRC-04-44, "Westinghouse Responses to NRC Request for Additional Information (RAIs) on Optimized ZIRLO' Topical -

Addendum 1 to WCAP-12610-P-A," dated August 4, 2004 (ML042240411)

5. NRC letter to Westinghouse, "Satisfaction of Conditions 6 and 7 of the U. S. Nuclear Regulatory Commission Safety Evaluation for Westinghouse Electric Company Addendum 1 to WCAP-12610-P-A & CENP-404-P-A, 'Optimized ZIRLO',' Topical Report," August 3, 2016 (ML16173A354)

6. TVA Letter to NRC, CNL-18-016, Watts Bar Nuclear Plant Unit 2 - Application to Revise License Condition 2.C(4) PAD4TCD (391-WBN-TS-18-03), dated March 5, 2018 (ML18064A192)

7. TVA Letter to NRC, CNL-18-058, Supplement to Application to Revise Watts Bar Nuclear Plant Unit 2 - License Condition 2.C(4) PAD4TCD (391-WBN-TS-18-03)

(EPID L-2018-LLA-0051), dated April 27, 2018 (ML18137A193)

8. TVA Letter to NRC, CNL-17-144, Application to Revise Watts Bar Unit 2 Technical Specification 4.2.1, Fuel Assemblies, and Watts Bar Units 1 and 2 Technical Specifications Related to Fuel Storage (WBN-TS-17-028), dated December 20, 2017 (ML17354B282)

9. TVA Letter to NRC, CNL-18-018, Supplement to Application to Revise Watts Bar Unit 2 Technical Specification 4.2.1, Fuel Assemblies, and Watts Bar Units 1 and 2 Technical Specifications Related to Fuel Storage (WBN-TS-17-028), dated February 15, 2018 (ML18047A181)

10. TVA Letter to NRC, CNL-18-051, Correction to Application to Revise Watts Bar Unit 2 Technical Specification 4.2.1, Fuel Assemblies, and Watts Bar Units 1 and 2 Technical Specifications Related to Fuel Storage (WBN-TS-17-028), dated April 9, 2018 (ML18100A953)

11. NRC letter to FirstEnergy Nuclear Operating Company, Beaver Valley Power Station, Unit Nos. 1 and 2-Issuance of Amendment Nos. 302 and 191 Regarding the Use of Optimized ZIRLO' Fuel Rod Cladding (CAC Nos. MF9580 and MF9581; EPID L-2017-LLA-0201), dated March 1, 2018 (ML18022B116)

12. NRC letter to FirstEnergy Nuclear Operating Company, Beaver Valley Power Station, Unit Nos. 1 and 2-Exemption from the Requirements of 10 CFR 50.46 and Appendix K to 10 CFR Part 50 to Allow the Use of Optimized ZIRLO' Fuel Rod Cladding (CAC Nos. MF9582 and MF9583; EPID L-2017-LLE-0011), dated March 1, 2018 (ML17313A550)

CNL-18-086 E1-14 of 14

13. NRC letter to Arizona Public Service Company, Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Exemption from the Requirements of 10 CFR Part 50, Section 50.46 and Appendix K (CAC Nos. MF8079, MF8080, and MF8081; EPID L-2016-LLE-0001), dated January 23, 2018 [ML17319A207 (Proprietary) and ML17319A214]

14. NRC letter to Arizona Public Service Company, Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Issuance of Amendments to Revise Technical Specifications to Support the Implementation of Next Generation Fuel (CAC Nos. MF8076, MF8077, and MF8078; EPID L-2016-LLA-0005), dated January 23, 2018 [ML17319A103 (Proprietary) and ML17319A107]

15. NRC letter to Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station - Issuance of Amendment Re: Use of Optimized ZIRLO' Fuel Rod Cladding (CAC No. MF7285), dated August 3, 2016 (ML16179A293)

16. NRC letter to Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station - Exemption from the Requirements of 10 CFR Section 50.46 and Appendix K of 10 CFR Part 50 to Allow the Use of Optimized ZIRLO' Clad Fuel Rods (CAC No. MF7286), dated August 2, 2016 (ML16179A440)

17. NRC letter to NextEra Energy Seabrook LLC, "Seabrook Station, Unit No. 1 -

Issuance of Amendment Regarding the Use of Optimized ZIRLO' Fuel Rod Cladding Material (TAC No. MF2410)," dated March 5, 2014 (ML13213A143)

18. NRC letter to NextEra Energy Seabrook LLC, "Seabrook Station, Unit 1 - Exemption from the Requirements of 10 CFR Section 50.46 and Appendix K to10 CFR Part 50 to Allow the Use of Optimized ZIRLO' Clad Fuel Rods (TAC No. MF2411)," dated March 5, 2014 (ML13213A074)

19. NRC letter to Exelon Generation Company, LLC, Issuance of Amendment Regarding the Use of Optimized ZIRLO' (CAC No. MF8299)," dated June 21, 2017 (ML17131A066)

20. NRC letter to Exelon Generation Company, LLC, Exemption from the Requirements of 10 CFR Section 50.46 and Appendix K to10 CFR Part 50 to Allow the Use of Optimized ZIRLO' Clad Fuel Rods (CAC No. MF8300)," dated June 21, 2017 (ML17131A113)

21. Arizona Public Service Company letter to NRC, Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Renewed Operating License Nos. NPF-41, NPF-51, NPF-74 Response to NRC Staff Request for Additional Information Regarding License Amendment and Exemption Requests Related to the Implementation of Next Generation Fuel (NGF), dated June 2, 2017 (ML17153A373)

22. Wolf Creek Nuclear Operating Corporation letter to NRC, Docket No. 50-482:

Response to Request for Additional Information Regarding License Amendment Request to Allow Use of Optimized ZIRLOTM, dated May 19, 2016 (ML16161A509)

CNL-18-086 Proposed TS Changes (Mark-Ups) for WBN Unit 1

Design Features 4.0 (continued)

Watts Bar Unit 1 4.0-1 Amendment 8, 40, 48, 67, 77, 86, 107, XXX 4.0 DESIGN FEATURES 4.1 Site 4.1.1 Site and Exclusion Area Boundaries The site and exclusion area boundaries shall be as shown in Figure 4.1-1.

4.1.2 Low Population Zone (LPZ)

The LPZ shall be as shown in Figure 4.1-2 (within the 3-mile circle).

4.2 Reactor Core 4.2.1 Fuel Assemblies The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Zircalloy, or ZIRLOirlo, or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. For Unit 1 Watts Bar is authorized to place a maximum of 1792 Tritium Producing Burnable Absorber Rods into the reactor in an operating cycle.

4.2.2 Control Rod Assemblies The reactor core shall contain 57 control rod assemblies. The control material shall be either silver-indium-cadmium or boron carbide with silver indium cadmium tips as approved by the NRC.

Reporting Requirements 5.9 (continued)

Watts Bar-Unit 1 5.0-30 Amendment 7, 11, 20, 31, 46, XXX 5.9 Reporting Requirements 5.9.5 CORE OPERATING LIMITS REPORT (COLR) (continued)

3.

WCAP-10216-P-A, Revision 1A, RELAXATION OF CONSTANT AXIAL OFFSET CONTROL F(Q) SURVEILLANCE TECHNICAL SPECIFICATION, February 1994 (W Proprietary). (Methodology for Specifications 3.2.1 - Heat Flux Hot Channel Factor (W(Z) Surveillance Requirements For F(Q) Methodology) and 3.2.3 - Axial Flux Difference (Relaxed Axial Offset Control).)

4.

WCAP-12610-P-A, VANTAGE + FUEL ASSEMBLY REFERENCE CORE REPORT, April 1995. (W Proprietary). (Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor).

5.

WCAP-15088-P, Rev. 1, Safety Evaluation Supporting A More Negative EOL Moderator Temperature Coefficient Technical Specification for the Watts Bar Nuclear Plant, July 1999, (W Proprietary), as approved by the NRC staffs Safety Evaluation accompanying the issuance of Amendment No. 20 (Methodology for Specification 3.1.4 - Moderator Temperature Coefficient.).

6.

Caldon, Inc. Engineering Report-80P, Improving Thermal Accuracy and Plant Safety While Increasing Operating Power Level Using the LEFM' System, Revision 0, March 1997; and Caldon, Inc.

Engineering Report-160P, Supplement to Topical Report ER-80P:

Basis for a Power Uprate With the LEFM', Revision 0, May 2000; as approved by the NRC staffs Safety Evaluation accompanying the issuance of Amendment No. 31.

7.

WCAP-11397-P-A, Revised Thermal Design Procedure, April 1989.

(Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

8.

WCAP-15025-P-A, Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17 x 17 Rod Bundles with Modified LPD Mixing Vane Grids, April 1999. (Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9.

WCAP-14565-P-A, VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis, October 1999. (Methodology for Specification 3.2.2 -

Nuclear Enthalpy Rise Hot Channel Factor).

10.

WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'."

c.

The core operating limits shall be determined such that all applicable limits (e.g.,

fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d.

The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.

CNL-18-086 Proposed TS Changes (Mark-Ups) for WBN Unit 2

Design Features 4.0 (continued)

Watts Bar - Unit 2 4.0-1 Amendment XX 4.0 DESIGN FEATURES 4.1 Site 4.1.1 Site and Exclusion Area Boundaries The site and exclusion area boundaries shall be as shown in Figure 4.1-1.

4.1.2 Low Population Zone (LPZ)

The LPZ shall be as shown in Figure 4.1-2 (within the 3-mile circle).

4.2 Reactor Core 4.2.1 Fuel Assemblies The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of ZIRLOirlo or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material.

Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.

4.2.2 Control Rod Assemblies The reactor core shall contain 57 control rod assemblies. The control material shall be silver indium cadmium as approved by the NRC.

Reporting Requirements 5.9 5.9 Reporting Requirements (continued)

Watts Bar - Unit 2 5.0-32 Amendment XX 5.9.5 CORE OPERATING LIMITS REPORT (COLR) (continued)

5. WCAP-15088-P, Rev. 1, Safety Evaluation Supporting A More Negative EOL Moderator Temperature Coefficient Technical Specification for the Watts Bar Nuclear Plant, July 1999, (W Proprietary), as approved by the NRC staffs Safety Evaluation accompanying the issuance of Amendment No. 20 (Methodology for Specification 3.1.4 - Moderator Temperature Coefficient.).

6. WCAP-11397-P-A, Revised Thermal Design Procedure, April 1989.

(Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

7. WCAP-15025-P-A, Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17 x 17 Rod Bundles with Modified LPD Mixing Vane Grids, April 1999. (Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

8. WCAP-14565-P-A, VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis, October 1999. (Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9a. WCAP-12472-P-A, BEACON' CORE MONITORING AND OPERATIONS SUPPORT SYSTEM, August 1994, (W Proprietary).

(Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor, and 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9b. WCAP-12472-P-A, Addendum 1-A, BEACON' MONITORING AND OPERATIONS SUPPORT SYSTEM, January 2000, (W Proprietary).

(Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor, and 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9c. WCAP-12472-P-A, Addendum 2-A, BEACON' MONITORING AND OPERATIONS SUPPORT SYSTEM (WCAP-12472-P-A) Addendum 2, April 2002, (W Proprietary) (Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor, and 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9d. WCAP-12472-P-A, Addendum 4, BEACON' CORE MONITORING AND OPERATIONS SUPPORT SYSTEM, Addendum 4, September 2012, (W Proprietary) (Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor, and 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

10 WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'."

CNL-18-086 Proposed TS Changes (Final Typed) for WBN Unit 1

Design Features 4.0 (continued)

Watts Bar Unit 1 4.0-1 Amendment 8, 40, 48, 67, 77, 86, 107, XXX 4.0 DESIGN FEATURES 4.1 Site 4.1.1 Site and Exclusion Area Boundaries The site and exclusion area boundaries shall be as shown in Figure 4.1-1.

4.1.2 Low Population Zone (LPZ)

The LPZ shall be as shown in Figure 4.1-2 (within the 3-mile circle).

4.2 Reactor Core 4.2.1 Fuel Assemblies The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of Zircaloy, ZIRLO, or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used. Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases.

A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions. For Unit 1 Watts Bar is authorized to place a maximum of 1792 Tritium Producing Burnable Absorber Rods into the reactor in an operating cycle.

4.2.2 Control Rod Assemblies The reactor core shall contain 57 control rod assemblies. The control material shall be either silver-indium-cadmium or boron carbide with silver indium cadmium tips as approved by the NRC.

Reporting Requirements 5.9 (continued)

Watts Bar-Unit 1 5.0-30 Amendment 7, 11, 20, 31, 46, XXX 5.9 Reporting Requirements 5.9.5 CORE OPERATING LIMITS REPORT (COLR) (continued)

3.

WCAP-10216-P-A, Revision 1A, RELAXATION OF CONSTANT AXIAL OFFSET CONTROL F(Q) SURVEILLANCE TECHNICAL SPECIFICATION, February 1994 (W Proprietary). (Methodology for Specifications 3.2.1 - Heat Flux Hot Channel Factor (W(Z) Surveillance Requirements For F(Q) Methodology) and 3.2.3 - Axial Flux Difference (Relaxed Axial Offset Control).)

4.

WCAP-12610-P-A, VANTAGE + FUEL ASSEMBLY REFERENCE CORE REPORT, April 1995. (W Proprietary). (Methodology for Specification 3.2.1 - Heat Flux Hot Channel Factor).

5.

WCAP-15088-P, Rev. 1, Safety Evaluation Supporting A More Negative EOL Moderator Temperature Coefficient Technical Specification for the Watts Bar Nuclear Plant, July 1999, (W Proprietary), as approved by the NRC staffs Safety Evaluation accompanying the issuance of Amendment No. 20 (Methodology for Specification 3.1.4 - Moderator Temperature Coefficient.).

6.

Caldon, Inc. Engineering Report-80P, Improving Thermal Accuracy and Plant Safety While Increasing Operating Power Level Using the LEFM' System, Revision 0, March 1997; and Caldon, Inc.

Engineering Report-160P, Supplement to Topical Report ER-80P:

Basis for a Power Uprate With the LEFM', Revision 0, May 2000; as approved by the NRC staffs Safety Evaluation accompanying the issuance of Amendment No. 31.

7.

WCAP-11397-P-A, Revised Thermal Design Procedure, April 1989.

(Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

8.

WCAP-15025-P-A, Modified WRB-2 Correlation, WRB-2M, for Predicting Critical Heat Flux in 17 x 17 Rod Bundles with Modified LPD Mixing Vane Grids, April 1999. (Methodology for Specification 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor).

9.

WCAP-14565-P-A, VIPRE-01 Modeling and Qualification for Pressurized Water Reactor Non-LOCA Thermal-Hydraulic Safety Analysis, October 1999. (Methodology for Specification 3.2.2 -

Nuclear Enthalpy Rise Hot Channel Factor).

10.

WCAP-12610-P-A and CENPD-404-P-A, Addendum 1-A, "Optimized ZIRLO'."

c.

The core operating limits shall be determined such that all applicable limits (e.g.,

fuel thermal mechanical limits, core thermal hydraulic limits, Emergency Core Cooling Systems (ECCS) limits, nuclear limits such as SDM, transient analysis limits, and accident analysis limits) of the safety analysis are met.

d.

The COLR, including any midcycle revisions or supplements, shall be provided upon issuance for each reload cycle to the NRC.

CNL-18-086 Proposed TS Changes (Final Typed) for WBN Unit 2

Design Features 4.0 (continued)

Watts Bar - Unit 2 4.0-1 Amendment XX 4.0 DESIGN FEATURES 4.1 Site 4.1.1 Site and Exclusion Area Boundaries The site and exclusion area boundaries shall be as shown in Figure 4.1-1.

4.1.2 Low Population Zone (LPZ)

The LPZ shall be as shown in Figure 4.1-2 (within the 3-mile circle).

4.2 Reactor Core 4.2.1 Fuel Assemblies The reactor shall contain 193 fuel assemblies. Each assembly shall consist of a matrix of ZIRLO or Optimized ZIRLO' clad fuel rods with an initial composition of natural or slightly enriched uranium dioxide (UO2) as fuel material. Limited substitutions of zirconium alloy or stainless steel filler rods for fuel rods, in accordance with approved applications of fuel rod configurations, may be used.

Fuel assemblies shall be limited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design bases. A limited number of lead test assemblies that have not completed representative testing may be placed in nonlimiting core regions.