Agent Name |
Californium |
CAS Number |
7440-71-3 |
Formula |
Cf |
Major Category |
Radiation Hazards |
Category |
Radionuclides |
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."
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Exposure Assessment |
Half Life |
Biological half-life: 20 years (liver) and 50 years (bone); [ANL Radiological Fact Sheets] |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: CALIFORNIUM, RADIOACTIVE IONIZING RADIATION
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