Major Category
Physical/Radiation
Description
Silver-gray metal; [Argonne]
Sources/Uses
Technetium is the first man-made element, produced in 1937 by deuteron bombardment of molybdenum. All isotopes are radioactive. Six atoms of technetium are created for every 100 fissions of uranium. Technetium is a waste product in spent nuclear fuel. Of the ten major isotopes, Tc-99 is the one of most concern as an environmental contaminant. The half-life of Tc-99 is 210,000 years. Used in steel as a corrosion inhibitor, but this use is limited by the radioactivity of technetium; Tc-99m is used in nuclear medicine; [Argonne]
Comments
Most Important Radionuclide: Tc-99m
Source: Decay of molybdenum-99
Half-Life: 6 hours
Decay Mode: Isomeric Transition (gamma) Decay
GI Absorption: 50-80% of technetium pertechnetate (TcO4)
Lung Clearance Half-Time: Weeks for oxides, hydroxides, halides, and nitrates; Days for all other compounds;
Critical Organ: Total body
Internal Toxicity: Low
Annual Limit on Intake: 80 mCi
Gamma Ray Constant: 0.6 R/h @ 1 cm per mCi
Tenth-Value Layer: 0.9 mm Pb
Radiation Energy (MeV): Gamma 0.141 (88%)
[See Glossary for references.] See "Radiation, ionizing."
Processes
Industrial Processes with risk of exposure: