2023-19909. Amended Record of Decision for the Production of Tritium in Commercial Light Water Reactors

AGENCY:

National Nuclear Security Administration, Department of Energy.

ACTION:

Amended record of decision.

SUMMARY:

The National Nuclear Security Administration (NNSA), a semi-autonomous agency within the Department of Energy (DOE), is announcing this amendment to the June 22, 2016, Record of Decision (ROD) for the Final Supplemental Environmental Impact Statement for the Production of Tritium in a Commercial Light Water Reactor (CLWR SEIS) (DOE/EIS–0288–S1). NNSA is amending the 2016 decision in partnership with the Tennessee Valley Authority (TVA). TVA is considering increasing the number of TPBARs irradiated in their reactors at Watts Bar Nuclear Plant (WBN) using tritium-producing burnable absorber rods (TPBARs). NNSA initially decided to implement the CLWR SEIS Preferred Alternative, Alternative 6, which allows for the irradiation of up to a total of 5,000 TPBARs every 18 months using TVA reactors at both the Watts Bar and Sequoyah sites. Subsequent to the CLWR SEIS, WBN Unit 1 increased tritium production under Unit 1 License Amendment #107 (July 2016) and Unit 2 tritium production was authorized under Unit 2 License Amendment #27 (May 2019). Hence, TVA and NNSA are now opting to choose the previously analyzed CLWR SEIS Alternative 4, which allows for the irradiation of up to a total of 5,000 TPBARs every 18 months at the Watts Bar site using Watts Bar Units 1 and 2.

FOR FURTHER INFORMATION CONTACT:

For information on NNSA's NEPA process, please contact Mr. James Sanderson, NEPA Compliance Officer, National Nuclear Security Administration, Office of General Counsel, Telephone [phone]; or by email to [e-mail]. This Amended Record of Decision is available on the internet at https://energy.gov/​nepa. The 2016 ROD, the CLWR SEIS, and related NEPA documents are available on the DOE NEPA website at https://www.energy.gov/​nepa/​doe-environmental-impact-statements.

SUPPLEMENTARY INFORMATION:

NNSA is the lead Federal agency responsible for maintaining and enhancing the safety, security, reliability, and performance of the United States (U.S.) nuclear weapons stockpile. Tritium, a radioactive isotope of hydrogen, is an essential component of every weapon in the U.S. nuclear weapons stockpile and must be replenished periodically due to its short half-life. In March 1999, DOE published the 1999 EIS, which addressed the production of tritium in the TVA's Watts Bar and Sequoyah nuclear reactors using TPBARs. The 1999 EIS assessed the potential environmental impacts of irradiating up to 3,400 TPBARs per reactor per fuel cycle (a fuel cycle lasts about 18 months). On May 14, 1999, DOE published the ROD for the 1999 EIS (64 FR 26369) in which it announced its decision to enter into an agreement with TVA to irradiate TPBARs in the Watts Bar Unit 1 reactor (Watts Bar 1) in Rhea County, Tennessee, near Spring City; and Sequoyah Units 1 and 2 reactors (Sequoyah 1 and 2) in Hamilton County, Tennessee, near Soddy-Daisy. In 2002, TVA received license amendments from the U.S. Nuclear Regulatory Commission (NRC) to irradiate TPBARs in those reactors. (However, TVA's license for the Sequoyah reactors no longer allows for the irradiation of TPBARs.) Since 2003, TVA has been irradiating TPBARs for NNSA by irradiating TPBARs only in Watts Bar 1. (In 2020, TVA began irradiating TPBARs in Watts Bar 2.) After irradiation, NNSA transports the TPBARs to the Tritium Extraction Facility at the DOE Savannah River Site in South Carolina. NNSA's Interagency Agreement with TVA to irradiate TPBARs is in effect until the earlier of either (a) November 30, 2035, or (b) the date TVA no longer has a pressurized water reactor in operation.

NNSA prepared the 2016 CLWR SEIS to update the environmental analyses in the 1999 Final Environmental Impact Statement for the Production of Tritium in a Commercial Light Water Reactor (DOE/EIS–0288; the 1999 EIS). The 2016 CLWR SEIS provides analysis of the potential environmental impacts from TPBAR irradiation based on a conservative estimate of the tritium permeation rate through the TPBAR cladding, NNSA's revised estimate of the maximum number of TPBARs necessary to support the current and projected future tritium supply requirements, and a maximum production scenario of irradiating no more than a total of 5,000 TPBARs every 18 months. NNSA initially decided to implement the Preferred Alternative, Alternative 6, which allows for the irradiation of up to a total of 5,000 TPBARs every 18 months using TVA reactors at both the Watts Bar and Sequoyah sites. Although near-term tritium requirements could likely be met with the irradiation of 2,500 TPBARs every 18 months, at the time, this decision provided the greatest flexibility to meet potential future needs that could arise from various plausible but unexpected events. Subsequent to the 2016 SEIS, WBN Unit 1 increased the irradiation of TPBARs under Unit 1 License Amendment #107 (July 2016) and Unit 2 TPBAR irradiation was authorized under Unit 2 License Amendment #27 (May 2019). Hence, TVA and NNSA are now opting to choose the previously analyzed CLWR SEIS Alternative 4, which allows for the irradiation of up to a total of 5,000 TPBARs every 18 months at the Watts Bar site using Watts Bar 1 and 2. TVA noted new information or circumstances relevant to environmental concerns that could potentially have a bearing on the current proposal or its impacts. This new information was analyzed in a February 6, 2023 TVA memorandum, “Determination of NEPA Adequacy, Production of Tritium in a Commercial Light Water Nuclear Reactor (Watts Bar Nuclear Plant), Tennessee Valley Authority.” In this memo, TVA addressed their recent review of the 2016 CLWR SEIS to determine if additional environmental review under NEPA was needed, consistent with CEQ regulations at 40 CFR 1502.9(d). The analysis demonstrated that the current proposal does not represent a substantive change to operations, activities, and associated impacts assessed in existing NEPA documentation. Both the TVA analysis and the CLWR SEIS analysis indicate that there would not be any significant increase in radiation exposure associated with TPBAR irradiation for facility workers or the public. For all analyzed alternatives (including both Alternatives 4 and 6), estimated radiation exposures would remain well below regulatory limits. The calculated estimated exposures for normal reactor operations with even the maximum number of TPBARs are comparable to those for normal reactor operation without TPBARs.

Amended Decision

NNSA is amending its previous decision (81 FR 40685), which was to choose the 2016 CLWR SEIS's Alternative 6 that assumes TVA would irradiate up to a total of 5,000 TPBARs every 18 months using both the Watts Bar and Sequoyah sites. Because TVA would irradiate a maximum of 2,500 TPBARs in any one reactor, this could involve the use of one or both reactors at each of the sites. Instead, NNSA's new decision is to choose the 2016 CLWR SEIS's Alternative 4 that assumes TVA would irradiate up to a total of 5,000 TPBARs every 18 months at the Watts Bar site using Watts Bar 1 and 2 reactors. Since TVA would irradiate a maximum of 2,500 TPBARs in any one reactor, this would involve use of both Watts Bar reactors. Under this decision, TVA will not irradiate TPBARs for tritium production at the Sequoyah site.

Basis for Decision

The environmental impacts of this proposed action have been addressed in previous environmental impact statements, i.e., the 1999 Final EIS for the Production of Tritium in a Commercial Light Water Reactor (DOE/EIS–0288) and the 2016 CLWR SEIS. However, TVA staff reviewed new information or circumstances relevant to environmental concerns that could potentially have a bearing on the current proposal or its impacts. This new information was analyzed in a February 6, 2023 TVA memorandum, i.e., “Determination of NEPA Adequacy, Production of Tritium in a Commercial Light Water Nuclear Reactor (Watts Bar Nuclear Plant), Tennessee Valley Authority.” In this memo, TVA addresses their recent review of the 2016 CLWR SEIS to determine if additional environmental review under NEPA was needed, consistent with CEQ regulations at 40 CFR 1502.9(d). During an interagency teleconference held in May 2021, NNSA requested information from TVA to help NNSA in its determination of the adequacy of the 2016 SEIS as far as TVA's updated proposal. Additional information given to NNSA addresses anticipated effects on the amount of spent fuel to be generated at Watts Bar, the fuel cycle there, and the amount of tritiated wastewater estimated to be generated from TPBAR irradiation. In terms of the amount of spent fuel to be generated at Watts Bar, TVA's current proposal would result in 36 additional fuel assemblies every 18 months. The SEIS assumed up to 41 additional fuel assemblies, so it provides a conservative bounding analysis of the approximately 2500 TPBAR equilibrium core designs. There would be additional spent fuel generated with the new proposal. However, TVA has assured NNSA that it has infrastructure in place to manage the increased volume of spent nuclear fuel assemblies. Regarding the new proposal's effects on the fuel cycle, the cycle length is only mentioned in the SEIS twice, and only in the context of being a “potential uncertainty” in determining if it was necessary to assume in the SEIS a higher, more conservative tritium permeation rate. TVA does not consider the operating cycle length to be uncertain, and it also does not anticipate that irradiation of up to 2500 TPBARs at each reactor would affect the typical fuel cycle. Therefore, the issue has no bearing on the review for adequacy of the SEIS for any future TVA action to irradiate up to 5000 TPBARs at Watts Bar. Lastly, the estimated amount of tritiated wastewater (due to permeation from the TPBARs into the cooling water) was not identified in the SEIS, as it is difficult to separate this out from other releases from such things as turbine building sumps, floor drain collector sumps, groundwater sumps, etc. However, to keep maximum tritium concentrations low, TVA will use a “feed and bleed” technique, which will require additional cooling water per fuel cycle in order to ensure that TVA discharges are within regulatory limits. TVA estimates that using this technique will increase water usage by approximately 25% but is not expected to affect environmental impacts. The current proposal does not represent a substantive change to operations, activities, and associated impacts assessed in existing NEPA documentation. Therefore, the decision to choose the previously analyzed 2016 CLWR SEIS Alternative 4, along with the updated analysis provided by TVA (summarized previously) and confirmed by NNSA, is reasonable, and accordingly, no further NEPA analysis of this TVA proposal is required.

Signing Authority

This document of the Department of Energy was signed on June 29, 2023, by Jill Hruby, Under Secretary for Nuclear Security and Administrator, NNSA, pursuant to delegated authority from the Secretary of Energy. That document with the original signature and date is maintained by DOE. For administrative purposes only, and in compliance with requirements of the Office of the Federal Register, the undersigned DOE Federal Register Liaison Officer has been authorized to sign and submit the document in electronic format for publication, as an official document of the Department of Energy. This administrative process in no way alters the legal effect of this document upon publication in the Federal Register .

Signed in Washington, DC, on September 11, 2023.

Treena V. Garrett,

Federal Register Liaison Officer, U.S. Department of Energy.