CNL-16-195, Spent Fuel Pool Evaluation Supplemental Report - Response to NRC Request for Information, Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident

Spent Fuel Pool Evaluation Supplemental Report - Response to NRC Request for Information, Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident

ML16357A578
Person / Time
Site:	Watts Bar
Issue date:	12/22/2016
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-16-195, TAC MF3769
Download: ML16357A578 (6)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-16-195 December 22, 2016 10 CFR 50.4 10 CFR 50.54(f)

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating License Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391

Subject:

Spent Fuel Pool Evaluation Supplemental Report for Watts Bar Nuclear Plant, Units 1 and 2 - Response to NRC Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)

Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident

References:

1. NRC Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012 (ML12053A340)

2. NRC Letter, Final Determination of Licensee Seismic Probabilistic Risk Assessments Under the Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendation 2.1 Seismic of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated October 27, 2015, (ML15194A015)

3. NEI letter to NRC, Request for Endorsement of Seismic Evaluation Guidance: Spent Fuel Pool Integrity Evaluation (EPRI 3002007148),

dated February 23, 2016 (ML16055A017)

4. EPRI 3002007148, Seismic Evaluation Guidance, Spent Fuel Pool Integrity Evaluation, dated February 2016 (ML16055A021)

U.S. Nuclear Regulatory Commission CNL-16-195 Page 2 December 22, 2016

5. NRC letter to NEI, Endorsement of Electrical Power Research Institute Report 3002007148, Seismic Evaluation Guidance: Spent Fuel Pool Integrity Evaluation, dated March 18, 2016 (ML15350A158)

6. TVA letter to NRC, Tennessee Valley Authoritys Seismic Hazard and Screening Report (CEUS Sites), Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 31, 2014 (ML14098A478)

7. NRC letter to TVA, Watts Bar Nuclear Plant, Unit 1 - Staff Assessment of Information provided Pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f), Seismic Hazard Reevaluations Relating to Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima DAI-ICHI Accident (TAC No. MF3769), dated October 5, 2015 (ML15055A543)

8. NRC letter to TVA, Watts Bar Nuclear Plant, Unit 2 - Staff Assessment of Information provided Pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f), Seismic Hazard Reevaluations Relating to Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima DAI-ICHI Accident (TAC No. MF3769), dated October 5, 2015 (ML15111A377)

9. EPRI 1025287, Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details [SPID] for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, dated February 2013 (ML12333A170)

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued a Request for Information pursuant to Title 10 of the Code of Federal Regulations (CFR) Part 50.54(f)

(Reference 1) to all power reactor licensees. Enclosure 1, Item (9) of the 50.54(f) letter requested addressees to provide limited scope spent fuel pool (SFP) evaluations. By letter dated October 27, 2015 (Reference 2), the NRC transmitted final seismic information request tables which identified that Watts Bar Nuclear Plant is to conduct a limited scope SFP Evaluation. Watts Bar Nuclear Plant, Units 1 and 2, share a common SFP. In Reference 3, the Nuclear Energy Institute (NEI) submitted the Electric Power Research Institute (EPRI) report, Seismic Evaluation Guidance Spent Fuel Pool Integrity Evaluation (EPRI 3002007148), (Reference 4) for NRC review and endorsement. NRC endorsement of EPRI 3002007148 was provided by Reference 5.

EPRI 3002007148 provides criteria for evaluating the seismic adequacy of a SFP to the reevaluated ground motion response spectrum (GMRS) hazard levels. This report supplements the guidance in the Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details (SPID) (Reference 9), for plants where the GMRS peak spectral

U:S. Nuclear Regulatory Commission CNL-16-195 Page 3 December 22, 2016 acceleration is less than or equal to 0.8g . Section 3.3 of EPRI 3002007148 lists the parameters to be verified to confirm that the results of the report are applicable to Watts Bar Nuclear Plant, and that the Watts Bar Nuclear Plant SFP is seismically adequate in accordance with NTTF 2.1 Seismic evaluation criteria .

The Enclosure to this letter provides the data for Watts Bar Nuclear Plant that confirms applicability of the EPRI 3002007148 criteria, confirms that the SFP is seismically adequate, and provides the requested information in response to Item (9) of the 50.54(f) letter associated with NTTF Recommendation 2.1 Seismic evaluation criteria.

This letter contains no new regulatory commitments.

If you have any questions regarding this submittal, please contact Russell Thompson at (423) 751-2567.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 22nd day of December 2016.

Respectfu Ily,

?ti*1 - .~' .  !\-- ,- *V' J. W . Shea Vice President, Nuclear Licensing

Enclosure:

Site-Specific Spent Fuel Pool Criteria, Watts Bar Nuclear Plant, Units 1 and 2 cc (Enclosure):

NRR Director - NRG Headquarters NRO Director - NRG Headquarters NRR JLD Director - NRG Headquarters NRG Regional Administrator - Region II NRG Project Manager - Watts Bar Nuclear Plant NRG Senior Resident Inspector - Watts Bar Nuclear Plant

ENCLOSURE Site-Specific Spent Fuel Pool Criteria Watts Bar Nuclear Plant, Units 1 and 2 E-1

Site-Specific Spent Fuel Pool Criteria Watts Bar Nuclear Plant, Units 1 and 2 The 50.54(f) letter requested that, in conjunction with the response to NTTF Recommendation 2.1, a seismic evaluation be made of the SFP. More specifically, plants were asked to consider all seismically induced failures that can lead to draining of the SFP. Such an evaluation would be needed for any plant in which the ground motion response spectrum (GMRS) exceeds the safe shutdown earthquake (SSE) in the 1 to 10 Hz frequency range. The staff confirmed through References 2 and 7 that the GMRS exceeds the SSE and concluded that a SFP evaluation is merited for Watts Bar Nuclear Plant. By letter dated March 18, 2016 (Reference 5),

the staff determined that EPRI 3002007148 was an acceptable approach for performing SFP evaluations for plants where the peak spectral acceleration is less than or equal to 0.8g.

The table below lists the criteria from Section 3.3 of EPRI 3002007148 along with data for Watts Bar Nuclear Plant that confirms applicability of the EPRI 3002007148 criteria and confirms that the SFP is seismically adequate and can retain adequate water inventory for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in accordance with NTTF 2.1 Seismic evaluation criteria.

SFP Criteria from EPRI 3002007148 Site-Specific Data Site Parameters

1. The site-specific GMRS peak The GMRS peak spectral acceleration submitted spectral acceleration at any for Watts Bar Nuclear Plant GMRS (Reference 6),

frequency should be less than or and accepted by the NRC in the Staff Assessment equal to 0.8g. letters (References 7 & 8) is 0.766g, which is 0.8g. Therefore, this criterion is met.

Structural Parameters

2. The structure housing the SFP The SFP is housed in the Auxiliary Building, which should be designed using an SSE is seismically designed to the site SSE with a PGA with a peak ground acceleration of 0.18g. The Watts Bar Nuclear Plant PGA is (PGA) of at least 0.1g. greater than 0.1g. Therefore, this criterion is met.

3. The structural load path to the SFP The structural load path from the foundation to the should consist of some combination SFP consists of reinforced concrete shear walls of reinforced concrete shear wall and a reinforced concrete pool bottom that is built elements, reinforced concrete frame integrally with the Auxiliary Building. Therefore, elements, post-tensioned concrete this criterion is met for Watts Bar Nuclear Plant.

elements and/or structural steel frame elements.

4. The SFP structure should be The SFP structure is included in the Watts Bar included in the Civil Inspection Nuclear Plant Civil Inspection Program in Program performed in accordance accordance with 10 CFR 50.65, which monitors the with Maintenance Rule. performance or condition of structures, systems, or components (SSCs) in a manner sufficient to provide reasonable assurance that these SSCs are capable of fulfilling their intended functions.

Therefore, this criterion is met for Watts Bar Nuclear Plant.

E-2

Site-Specific Spent Fuel Pool Criteria Watts Bar Nuclear Plant, Units 1 and 2 SFP Criteria from EPRI 3002007148 Site-Specific Data Non-Structural Parameters

5. To confirm applicability of the piping Piping attached to the SFP is evaluated to the SSE evaluation in Section 3.2 of EPRI in accordance with the Updated Final Safety 3002007148, piping attached to the Analysis Report (UFSAR). Therefore, this criterion SFP up to the first valve should have is met for Watts Bar Nuclear Plant.

been evaluated for the SSE.

6. Anti-siphoning devices should be Design provisions are in place to protect against installed on any piping that could significant water loss. The SFP cooling system lead to siphoning water from the suction connections enter near normal water level SFP. In addition, for any cases so that the SFP cannot be siphoned. SFP skimmer where active anti-siphoning devices pump suction and discharge piping are also are attached to 2-inch or smaller located near normal water level. The 10 SFP piping and have extremely large cooling water return line is truncated approximately extended operators, the valves 2.5 feet below normal water level. All cooling water should be walked down to confirm return lines contain an anti-siphon hole to prevent adequate lateral support. any significant loss of water from the SFP. In addition, an anti-siphon valve is located in transfer canal drain line to prevent draining the SFP when the transfer canal is open.

As described, anti-siphoning devices are installed on all SFP piping that could lead to siphoning.

Therefore, this criterion is met for Watts Bar Nuclear Plant.

As described, no anti-siphoning devices are attached to 2-inch or smaller piping with extremely large extended operators. Therefore, this criterion is met for Watts Bar Nuclear Plant.

7. To confirm applicability of the The Watts Bar Nuclear Plant SFP has a length of sloshing evaluation in Section 3.2 of 39.5 ft, a width of 31.7 ft, and a depth of 47.9 ft EPRI 3002007148, the maximum based on Watts Bar Nuclear Plant UFSAR.

SFP horizontal dimension (length or Therefore, this criterion is met.

width) should be less than 125 ft, the SFP depth should be greater than The Watts Bar Nuclear Plant GMRS maximum 36 ft, and the GMRS peak Sa should spectral acceleration in the frequency range equal be <0.1g at frequencies equal to or to or less than 0.3 Hz is 0.046g from Watts Bar less than 0.3 Hz.

Nuclear Plant GMRS submittal which is less than 0.1g. Therefore, this criterion is met.

8. To confirm applicability of the The surface area of the Watts Bar Nuclear Plant evaporation loss evaluation in SFP is approximately 1250 ft2, which is greater Section 3.2 of EPRI 3002007148, than 500 ft2; and licensed reactor thermal power for the SFP surface area should be Watts Bar Nuclear Plant Unit 1 is 3,459 MWt and greater than 500 ft2 and the licensed Unit 2 is 3,411 MWt which is less than 4,000 MWt reactor core thermal power should per unit. Therefore, this criterion are met for both be less than 4,000 MWt per unit. Units 1 and 2.

E-3