Key Issues
Californium-252: Supply and Funding Status
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July 2009
Key Facts
Production of Cf-252
Californium-252 is not found in nature and can only be produced in high-flux reactors. It is a strong neutron emitter by spontaneous fission; one microgram emits 170 million neutrons per minute. Its short half-life (2.6 years) means it decays at a rate of about 25 percent per year. New supplies to the user community thus need to be manufactured regularly.
Cf-252 is produced only at ORNL’s High Flux Irradiation Reactor (HFIR) and, in smaller amounts, at Russia’s Research Institute of Atomic Reactors facility. The output of this reactor is half that of ORNL’s and is used mainly by Russia and China. Oak Ridge thus accounts for two-thirds of the world’s supply, around 20 milligrams per year. DOE manages the program at an annual cost of about $6 million.
A Cf-252 production cycle takes six to eight months of in-reactor irradiation, followed by a four-month process of cooling, radiochemical processing and recovery. The process typically yields about 100 milligrams for commercial use. The irradiated wires or pellets are shipped to commercial source manufacturers who fabricate them into sealed capsules for sale to industry users.
Under new agreements concluded in May 2009 among DOE, source manufacturers and industry users, future irradiation campaigns will be conducted every two years.
July 2009
Key Facts
- Californium-252 (Cf-252) is a radioactive neutron source with widespread industrial uses. It is produced in high-energy research reactors. Cf-252 has a short decay period (2.6 years) and supplies need to be replenished regularly.
- Cf-252 is produced at Oak Ridge National Laboratory (ORNL) and at a reactor in Russia. Historically Cf-252 has been a byproduct of a program mostly funded by the U.S. Department of Energy (DOE), in support of transuranic waste research and defense purposes. Commercial industry funds the remaining production for various uses, including reactor startup and testing during nuclear fuel manufacture; process control in the cement, coal, oil and gas industries; cancer therapy; and university research.
- DOE has ended its transuranic test program at Oak Ridge, but Cf-252 production will continue in order to supply industrial and medical users.
- In May 2009, industry users and Cf-252 source manufacturers reached agreements with DOE to privately fund the Cf-252 program through FY 2012 with expectations that production will continue beyond that year.
Production of Cf-252
Californium-252 is not found in nature and can only be produced in high-flux reactors. It is a strong neutron emitter by spontaneous fission; one microgram emits 170 million neutrons per minute. Its short half-life (2.6 years) means it decays at a rate of about 25 percent per year. New supplies to the user community thus need to be manufactured regularly.
Cf-252 is produced only at ORNL’s High Flux Irradiation Reactor (HFIR) and, in smaller amounts, at Russia’s Research Institute of Atomic Reactors facility. The output of this reactor is half that of ORNL’s and is used mainly by Russia and China. Oak Ridge thus accounts for two-thirds of the world’s supply, around 20 milligrams per year. DOE manages the program at an annual cost of about $6 million.
A Cf-252 production cycle takes six to eight months of in-reactor irradiation, followed by a four-month process of cooling, radiochemical processing and recovery. The process typically yields about 100 milligrams for commercial use. The irradiated wires or pellets are shipped to commercial source manufacturers who fabricate them into sealed capsules for sale to industry users.
Under new agreements concluded in May 2009 among DOE, source manufacturers and industry users, future irradiation campaigns will be conducted every two years.
