Production of Tritium in a Commercial Light Water Reactor—Supplemental Environmental Impact Statement

On April 3, 2017, TVA issued a Record of Decision (ROD) to implement the preferred alternative identified in the Final Supplemental Environmental Impact Statement (SEIS) on the Production of Tritium in a Commercial Light Water Reactor (CLWR), issued by the Nuclear National Security Administration (NNSA) and adopted by TVA in early 2016.

The NNSA is a semi-autonomous agency within the Department of Energy (DOE). DOE issued an EIS in 1999 on the CLWR program, which addressed the production of tritium in TVA reactors using tritium-producing burnable absorber rods (TPBARs). In the ROD for the CLWR EIS, DOE selected TVA’s Watts Bar Nuclear Plant Unit 1 and Sequoyah Nuclear Plant Units 1 and 2, located in Spring City and Soddy-Daisy, Tenn., respectively, for tritium production. TVA was a cooperating agency in the development of the CLWR EIS, and issued its ROD on the CLWR program in 2000. TVA has been producing tritium for NNSA at Watts Bar Unit 1 since 2004.

At the time of preparation of the 1999 EIS, it was estimated that tritium permeated through the wall of the TPBARs into the reactant coolant at a rate of 1 curie per TPBAR per year (there are approximately 10,000 curies of tritium produced by a TPBAR). Irradiation experience at Watts Bar has shown that the actual permeation rate is 3-4 curies per TPBAR per year. Therefore DOE/NNSA have issued the Final SEIS that analyzes the potential impacts from TPBAR irradiation at TVA sites on a conservative (e.g., bounding) estimate of the tritium permeation rate, as well as a conservative interpretation of DOE/NNSA’s revised estimate of the maximum number of TPBARs necessary to support current tritium supply requirements.

The Draft SEIS was issued for public comment in August 2014 and two public hearings were held in September 2014 in Athens and Chattanooga, Tennessee. Based on public and stakeholder input, the Final SEIS was revised to reflect the most current information on several issues, including tritium TPBAR irradiation quantities, the status of related NEPA documents, and updated accident analyses based on 2014 seismic information. These have not affected the prior conclusions in the Draft SEIS and the Final SEIS includes responses to the comments. The preferred alternative has been changed to Alternative 6, which would enable irradiating a total of up to 5,000 TPBARs at the Watts Bar and Sequoyah sites. This change in the preferred alternative is a result of changes in the estimate of tritium needs for national security. In June 2016, the NNSA published its decision to implement Alternative 6.

TVA was a cooperating agency in the development of the SEIS and adopted the Final SEIS in March 2016. On April 3, 2017, TVA published its ROD in the Federal Register stating its intent to implement Alternative 6 as well. As noted above, TVA currently irradiates TPBARs in Watts Bar Unit 1; the ROD notes the possibility of expanding the use of TPBARs to Watts Bar Unit 2 and/or either of the Sequoyah Nuclear Plant units, pending approval of the required operating license amendments by the Nuclear Regulatory Commission.  TVA received a license amendment from NRC for production of tritium in Watts Bar Unit 2 in May 2020 and started tritium production in Unit 2 in November 2020. 

External Contact

For general information on the CLWR program and the SEIS, contact:
Mr. Curtis Chambellan
CLWR SEIS Document Manager
P.O. Box 5400
Albuquerque, NM 87185-5400
Phone: (505) 845-5073
E-mail: [email protected]

External Document

The Final SEIS and the NNSA’s Record of Decision are available on the NNSA website.

Related Documents

TVA Record of Decision


More information on this environmental review can be obtained from:

Matthew Higdon
NEPA Specialist
[email protected]
400 West Summit Hill Drive, WT 11D
Knoxville, TN 37902