Major Category
Physical/Radiation
Description
A man-made, radioactive metal with a melting point of 900 degrees C; [Merck Index # 1716]
Sources/Uses
Californium is a byproduct of plutonium production. Two of the californium isotopes (Cf-249 and Cf-251) have half-lives longer than 20 years and are defined as transuranic wastes (TRU) produced in nuclear reactors. Of the ten known isotopes, only Cf-252 is used commercially in industrial radiography and in brachytherapy to treat cancer. About 3% of decays are by spontaneous fission producing neutrons and gamma rays. Cf-252 is a strong emitter of neutrons at a rate of 170 million neutrons per minute. [Argonne]
Comments
Most Important Radionuclide: Cf-252;
Source: Usually from neutron irradiation in a nuclear reactor;
Half-Life: 2.6 years
Effective Half-Life: 2.2 years
Specific Activity (Ci/gm): 540
Decay Mode: Alpha
GI Absorption: 0.05%
Lung Clearance Half-Time: Years for oxides and hydroxides; Weeks for all other compounds;
Critical Organ: Bone
Internal Toxicity: Very High
Annual Limit on Intake: 0.00002 mCi
Radiation Energy (MeV): Spontaneous fission (3.1%); Alpha 6.075 (15%); Alpha 6.12 (81.6%); [See Glossary for references.] See "Radiation, ionizing."
Half Life
Biological half-life: 20 years (liver) and 50 years (bone); [ANL Radiological Fact Sheets]
Other Information
No other related information on this agent was found.