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Tritium Production at TVA

Fact Sheet, November 2003
Chronology of Tritium Production

Fact Sheet
• Tritium is a radioactive isotope of hydrogen required by all U.S. nuclear weapons in order to function as designed. Tritium cannot be used alone to make a nuclear weapon.

• Because it decays at a rate of about 5.5 percent per year, tritium must be replaced periodically. The U.S. has not produced tritium since 1988, when the last tritium production reactor was shut down at Department of Energy’s (DOE) Savannah River Site. DOE currently dismantles U.S. nuclear weapons to meet immediate needs.

• DOE is responsible for reestablishing the capability to produce tritium by approximately 2005, in accordance with a Presidential directive, and therefore is implementing a program that uses civilian nuclear reactors to produce tritium for use in the nation’s nuclear weapons.

• As a corporation created by Congress, TVA has an obligation to and a long history of supporting the nation’s security requirements. TVA’s history of supporting U.S. national security requirements includes making material in Muscle Shoals, Alabama, that was used in military munitions and building dams that supplied power for the vital aluminum factories and Oak Ridge National Laboratory during World War II.

• At the request of DOE, TVA will again support the nation’s defense needs by providing irradiation services so that DOE can meet the requirements of the Presidential directive. TVA has signed an interagency agreement to use reactors at Watts Bar (and Sequoyah in the future) to produce tritium for DOE’s use.

• Watts Bar normally uses 12-foot-long rods containing boron carbide for the purpose of absorbing excess neutrons in the reactor cores. These rods control reactivity and assist in extending fuel life. The rods are called burnable absorber rods.

• The rods that will be used for tritium production are simply another type of burnable absorber rods. These rods use lithium aluminate ceramic rather than boron carbide to absorb neutrons.

• DOE developed a technology for producing tritium using lithium, rather than boron, in burnable absorber rods installed in commercial pressurized-water reactors. Neutron irradiation of the lithium burnable absorber in the reactor core converts the lithium to tritium. The tritium producing burnable absorber rods (TPBARs) will be removed from the fuel assemblies and shipped to the Savannah River Site, where DOE will extract the tritium.

• The TPBARs arrived at TVA physically intact and will leave TVA physically intact. The rods will be placed in a certain number of fuel assemblies and placed in Watts Bar’s reactor fuel assemblies, replacing burnable absorber rods.

• The TPBARs provide the same function as standard burnable absorber rods in the reactor core, except tritium will be produced and contained within the sealed rod when neutrons strike the lithium aluminate ceramic material.

•As soon as tritium gas is produced in the rod, it will be captured in a solid zirconium material in the rod called a “getter.” This getter is so effective that the rods will have to be heated to temperatures in excess of 1,000 degrees Centigrade at the Savannah River Site Tritium Extraction Facility before the tritium can be recovered.

• Watts Bar will operate its normal 18-month fuel cycle with TPBARs in the reactor, with employees continuing to operate and maintain equipment to high standards, as well as conducting appropriate plant testing and monitoring activities. TPBARs were placed in the Watts Bar reactor during the fall 2003 refueling and maintenance outage.

• The quantity of TPBARs in each reactor will vary. The actual number to be irradiated will be determined by national defense needs. After the TPBARs have been irradiated, they will be removed soon after refueling operations and shipped to DOE’s Savannah River Site Tritium Extraction Facility, where the tritium will be extracted.

• The tritium production process at Watts Bar will not change basic operations of the plants. This has been verified through the use of test reactors and a lead test assembly program at Watts Bar.

Chronology: 1999 - 2003
• Feb. 27, 1999 – Watts Bar operating cycle ends with 32 tritium producing burnable absorber rods (TPBARs) in the nuclear reactor. The rods were in four lead test assemblies (LTA) and were successfully irradiated during tests conducted by DOE in the reactor. The tests showed that irradiation of the special bars posed no technical difficulties and did not impact safe operation of the reactor. Subsequent examination of the TPBARS revealed that they performed as expected.

• May 6, 1999 – Then-U.S. Department of Energy Secretary Bill Richardson selects TVA’s Watts Bar and Sequoyah nuclear plants for the tritium production program. DOE says this is the most efficient alternative to ensure the continued safety, security, and reliability of the nation’s nuclear weapons stockpile.

• May 22, 1999 – The Secretary of Energy and the Chairman of the NRC sign a joint Memorandum of Understanding establishing the basis for NRC review and consultation regarding DOE’s use of commercial reactors for producing tritium. The memorandum supplements a 1978 agreement between DOE and NRC and relates solely to producing tritium.

• December 1999 – TVA’s Board of Directors approves an Interagency Agreement for TVA to provide services for tritium production effective January 2000. Under the terms of the agreement, TVA is responsible for providing irradiation services in the program; DOE assumes responsibility for all other aspects, and the agreement protects consumers of TVA power and TVA bondholders. According to the agreement, TVA will recover costs associated with the program and is given protection against any economic risks. TVA retains the right to operate the reactors for their primary mission of producing electricity.

• Aug. 20, 2001 – TVA submits a license amendment application to the NRC to produce tritium at Watts Bar.

• Sept. 21, 2001 – TVA submits a license amendment application to the NRC to produce tritium at Sequoyah.

• Sept. 23, 2002 – The NRC issues approval for Watts Bar’s license amendment.

• Sept. 30, 2002 – The NRC issues approval for Sequoyah’s license amendment.

• Dec. 13, 2002 – As a result of the Department of Energy’s December 13, 2002, direction on irradiation requirements, the Sequoyah site goes into a baseline standby phase as of January 1, 2003, and will remain in this phase until notified to prepare to irradiate TPBARs. The Watts Bar site goes into “Prepare to Irradiate” phase as of January 1, 2003, in anticipation of irradiation of TPBARs after the Watts Bar fall 2003 outage.

• During the future “Prepare to Irradiate” phase for Sequoyah, TVA will update procedures and programs, and certify readiness prior to the first operating cycle that TPBARs are irradiated. Lessons learned from the Watts Bar irradiation will be incorporated into the Sequoyah programs and procedures.

• September 2003 – DOE delivers TPBARs to Watts Bar Nuclear Plant. During the scheduled fall refueling outage, the TPBARs are placed in the reactor.

• October 20, 2003 – Watts Bar returns to service with TPBARs in the reactor.