ML15302A330

NRR E-mail Capture - Request for Additional Information - Watts Bar Unit 1 Tpbars (MF6050)

ML15302A330
Person / Time
Site:	Watts Bar
Issue date:	10/29/2015
From:	Robert Schaaf Watts Bar Special Projects Branch
To:	Arent G, Szabo C Tennessee Valley Authority
References
MF6050
Download: ML15302A330 (4)

Text

NRR-PMDAPEm Resource From: Schaaf, Robert Sent: Thursday, October 29, 2015 1:08 PM To: Szabo, Clinton William; Gordon Arent Cc: Dion, Jeanne

Subject:

Request for Additional Information - Watts Bar Unit 1 TPBARs (MF6050)

Attachments: TPBAR - SNPB RAIs.pdf Gentlemen, By letter dated March 31, 2015 (ADAMS Accession No. ML15098A446), the Tennessee Valley Authority (TVA) submitted an application for a license amendment to revise the Watts Bar Nuclear Plant (WBN) Unit 1 Technical Specifications (TS) to increase the maximum number of tritium producing burnable absorber rods and to delete outdated information related to the tritium production program at WBN Unit 1. These changes would revise TS 4.2.1, Fuel Assemblies, TS 3.5.1, Accumulators, Surveillance Requirement (SR) 3.5.1.4, and TS 3.5.4, Refueling Water Storage Tank, SR 3.5.4. TVA supplemented this request with letters dated May 27 and June 15, 2015 (ADAMS Accession Nos. ML15147A611 and ML15169B117, respectively).

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is attached to this e-mail. Draft questions were provided to your staff on October 15, 2015, for clarification of the requests. TVA has agreed to provide a response to this information request by November 30, 2015.

Please contact me if you have any questions regarding with this request.

Regards, Bob Robert G. Schaaf Senior Project Manager Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8G9A Washington, DC 20555 301-415-6020 (o)

Robert.Schaaf@nrc.gov 1

Hearing Identifier: NRR_PMDA Email Number: 2486 Mail Envelope Properties (0b4c6ba08ad94367a6ac41f6532dfcf3)

Subject:

Request for Additional Information - Watts Bar Unit 1 TPBARs (MF6050)

Sent Date: 10/29/2015 1:07:30 PM Received Date: 10/29/2015 1:07:00 PM From: Schaaf, Robert Created By: Robert.Schaaf@nrc.gov Recipients:

"Dion, Jeanne" <Jeanne.Dion@nrc.gov>

Tracking Status: None "Szabo, Clinton William" <cwszabo@tva.gov>

Tracking Status: None "Gordon Arent" <garent@tva.gov>

Tracking Status: None Post Office: HQPWMSMRS07.nrc.gov Files Size Date & Time MESSAGE 1529 10/29/2015 1:07:00 PM TPBAR - SNPB RAIs.pdf 232908 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION TENNESSEE VALLEY AUTHORITY FOR WATTS BAR NUCLEAR PLANT, UNIT 1 PROPOSED CHANGES TO INCREASE THE MAXIMUM NUMBER OF TRITIUM PRODUCING BURNABLE ABSORBER RODS PER CYCLE DOCKET NUMBER 50-390 (TAC NO. MF6050)

By letter dated March 31, 2015, the Tennessee Valley Authority (TVA) submitted an application for license amendment to revise the Technical Specifications to increase the maximum number of tritium producing burnable absorber rods and to delete outdated information related to the tritium production program at Watts Bar Nuclear Plant (WBN) Unit 1 (ADAMS Accession No. ML15098A446). These changes would revise TS 4.2.1, Fuel Assemblies, TS 3.5.1 Accumulators, Surveillance Requirement (SR) 3.5.1.4, TS 3.5.4, Refueling Water Storage Tank, and SR 3.5.4. TVA supplemented this request with letters dated in May and June 2015 (ADAMS Accession Nos. ML15147A611 and ML15169B117).

The 1XFOHDU5HJXODWRU\&RPPLVVLRQstaff has reviewed the application and has determined that additional information is required to complete the review.

1. TVA is requesting an increase of the maximum number of Tritium Producing Burnable Absorber Rods (TPBARs) that can be irradiated per cycle from 704 to 1,792.

(a) Provide a loading pattern of the Watts Bar Nuclear Plant (WBN) Unit 1 indicating the location of the TPBARs, integral fuel burnable absorber (IFBA) rods and describe their impact on core reactivity and the power distribution shape during a typical cycle of operation.

(b) Provide a detailed description of the impact of the increase in T3BAR loading in WBN Unit 1 on the enrichment of U-235 for the fresh fuel loading at WBN 8nit 1 by providing a comparison between a reference plant without TPBARs and a Tritium Producing Core (TPC) plant various enrichment zones.

2. Provide an evaluation of the impact of the TPBARs at WBN Unit 1 in comparison to these parameters for a reference core on the following parameters:

(a) Nuclear enthalpy hot rise factor (FHN)

(b) Total peaking factor (FQT)

(c) Axial power distributions at Beginning of Life (BOL) and End-of-life (EOL)

(d) Reactivity coefficients such as moderator temperature (MTC) and Doppler temperature (DTC) and the total power coefficients.

(e) Control rod worths and shutdown margin.

ENCLOSURE

3. TVA is requesting an increase of the maximum number of TPBARs that can be irradiated

per cycle from 704 to 1,792. Please explain how WKH proposed increase in TPBARs impactsthe following fuel design parameters and describe the methodologies used:

(a) Rod internal pressure as a function of fission gas release (FGR)

(b) Cladding stress (c) Cladding strain (d) Cladding oxidation and hydriding (e) Fuel temperature (f) Cladding fatigue (g) Fuel rod axial growth (h) Clad flattening (i) Clad creep

4. Westinghouse document LTR-NRC-12-18 states that fuel thermal conductivity

degradation (TCD) with burnup has an effect on safety parameters; fuel rod stored

energy, fuel rod centerline temperature, and Doppler power coefficient. Provide a

summary of WKHimpact of WKHincrease in the maximum number of TPBARs in WBN Unit 1 on theabove safety parameters and any otherV due to the lack of explicit treatment of TCD inWKHsafety analysis. Also extend your summary to any other fuel performance parametersthat may be affected due to the lack of TCD.

NRR-PMDAPEm Resource From: Schaaf, Robert Sent: Thursday, October 29, 2015 1:08 PM To: Szabo, Clinton William; Gordon Arent Cc: Dion, Jeanne

Subject:

Request for Additional Information - Watts Bar Unit 1 TPBARs (MF6050)

Attachments: TPBAR - SNPB RAIs.pdf Gentlemen, By letter dated March 31, 2015 (ADAMS Accession No. ML15098A446), the Tennessee Valley Authority (TVA) submitted an application for a license amendment to revise the Watts Bar Nuclear Plant (WBN) Unit 1 Technical Specifications (TS) to increase the maximum number of tritium producing burnable absorber rods and to delete outdated information related to the tritium production program at WBN Unit 1. These changes would revise TS 4.2.1, Fuel Assemblies, TS 3.5.1, Accumulators, Surveillance Requirement (SR) 3.5.1.4, and TS 3.5.4, Refueling Water Storage Tank, SR 3.5.4. TVA supplemented this request with letters dated May 27 and June 15, 2015 (ADAMS Accession Nos. ML15147A611 and ML15169B117, respectively).

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is attached to this e-mail. Draft questions were provided to your staff on October 15, 2015, for clarification of the requests. TVA has agreed to provide a response to this information request by November 30, 2015.

Please contact me if you have any questions regarding with this request.

Regards, Bob Robert G. Schaaf Senior Project Manager Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8G9A Washington, DC 20555 301-415-6020 (o)

Robert.Schaaf@nrc.gov 1

Hearing Identifier: NRR_PMDA Email Number: 2486 Mail Envelope Properties (0b4c6ba08ad94367a6ac41f6532dfcf3)

Subject:

Request for Additional Information - Watts Bar Unit 1 TPBARs (MF6050)

Sent Date: 10/29/2015 1:07:30 PM Received Date: 10/29/2015 1:07:00 PM From: Schaaf, Robert Created By: Robert.Schaaf@nrc.gov Recipients:

"Dion, Jeanne" <Jeanne.Dion@nrc.gov>

Tracking Status: None "Szabo, Clinton William" <cwszabo@tva.gov>

Tracking Status: None "Gordon Arent" <garent@tva.gov>

Tracking Status: None Post Office: HQPWMSMRS07.nrc.gov Files Size Date & Time MESSAGE 1529 10/29/2015 1:07:00 PM TPBAR - SNPB RAIs.pdf 232908 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION TENNESSEE VALLEY AUTHORITY FOR WATTS BAR NUCLEAR PLANT, UNIT 1 PROPOSED CHANGES TO INCREASE THE MAXIMUM NUMBER OF TRITIUM PRODUCING BURNABLE ABSORBER RODS PER CYCLE DOCKET NUMBER 50-390 (TAC NO. MF6050)

By letter dated March 31, 2015, the Tennessee Valley Authority (TVA) submitted an application for license amendment to revise the Technical Specifications to increase the maximum number of tritium producing burnable absorber rods and to delete outdated information related to the tritium production program at Watts Bar Nuclear Plant (WBN) Unit 1 (ADAMS Accession No. ML15098A446). These changes would revise TS 4.2.1, Fuel Assemblies, TS 3.5.1 Accumulators, Surveillance Requirement (SR) 3.5.1.4, TS 3.5.4, Refueling Water Storage Tank, and SR 3.5.4. TVA supplemented this request with letters dated in May and June 2015 (ADAMS Accession Nos. ML15147A611 and ML15169B117).

The 1XFOHDU5HJXODWRU\&RPPLVVLRQstaff has reviewed the application and has determined that additional information is required to complete the review.

1. TVA is requesting an increase of the maximum number of Tritium Producing Burnable Absorber Rods (TPBARs) that can be irradiated per cycle from 704 to 1,792.

(a) Provide a loading pattern of the Watts Bar Nuclear Plant (WBN) Unit 1 indicating the location of the TPBARs, integral fuel burnable absorber (IFBA) rods and describe their impact on core reactivity and the power distribution shape during a typical cycle of operation.

(b) Provide a detailed description of the impact of the increase in T3BAR loading in WBN Unit 1 on the enrichment of U-235 for the fresh fuel loading at WBN 8nit 1 by providing a comparison between a reference plant without TPBARs and a Tritium Producing Core (TPC) plant various enrichment zones.

2. Provide an evaluation of the impact of the TPBARs at WBN Unit 1 in comparison to these parameters for a reference core on the following parameters:

(a) Nuclear enthalpy hot rise factor (FHN)

(b) Total peaking factor (FQT)

(c) Axial power distributions at Beginning of Life (BOL) and End-of-life (EOL)

(d) Reactivity coefficients such as moderator temperature (MTC) and Doppler temperature (DTC) and the total power coefficients.

(e) Control rod worths and shutdown margin.

ENCLOSURE

3. TVA is requesting an increase of the maximum number of TPBARs that can be irradiated

per cycle from 704 to 1,792. Please explain how WKH proposed increase in TPBARs impactsthe following fuel design parameters and describe the methodologies used:

(a) Rod internal pressure as a function of fission gas release (FGR)

(b) Cladding stress (c) Cladding strain (d) Cladding oxidation and hydriding (e) Fuel temperature (f) Cladding fatigue (g) Fuel rod axial growth (h) Clad flattening (i) Clad creep

4. Westinghouse document LTR-NRC-12-18 states that fuel thermal conductivity

degradation (TCD) with burnup has an effect on safety parameters; fuel rod stored

energy, fuel rod centerline temperature, and Doppler power coefficient. Provide a

summary of WKHimpact of WKHincrease in the maximum number of TPBARs in WBN Unit 1 on theabove safety parameters and any otherV due to the lack of explicit treatment of TCD inWKHsafety analysis. Also extend your summary to any other fuel performance parametersthat may be affected due to the lack of TCD.