Tritium

DOE-HDBK-1129-99

10 CFR 835, "Occupational Radiation Protection"

40 CFR 261, "Identification and Listing of Hazardous Waste"

40 CFR 262, "Standards Applicable to Generators of Hazardous Waste"

40 CFR 302.4, "Designation of Hazardous Substances"

49 CFR 172, "Hazardous Materials Table, Special Provisions, Hazardous Materials

Communications, Emergency Response Information, and Training Requirements"

49 CFR 173, "Shippers General Requirements for Shipments and Packagings"

49 CFR 177, "Carriage by Public Highway"

49 CFR 178, "Specifications for Packaging"

62 FR 62079, Joint NRC/EPA Guidance on Testing Requirements for Mixed Radioactive and

Hazardous Waste, November 20, 1997

IAEA Technical Report Series #324, "Safe Handling of Tritium"

IAEA-SM-181/19, "Estimates of Dry Deposition and Plume Depletion over Forests and

Grassland"

ISO 7503-2, "Evaluation of Surface Contamination Part 2: Tritium Surface Contamination"

Office of Nuclear and Facility Safety Technical Notice 94-01, "Guidelines for Valves in Tritium

Service"

OSWER 9928.4-03, Waste Analysis at Facilities that Generate, Treat, Store, and Dispose of

Hazardous Wastes: A Guidance Manual, April 1994

Westinghouse Savannah River Company, WSRC-TR-94-0596, Titanium for Long Term Tritium

Storage (U), December 1994.

2.0 TRITIUM

Isotopes are elements that have the same atomic number (same number of protons in the nucleus)

but of different atomic mass (total number of protons plus neutrons in the nucleus). There are

three isotopes of hydrogen. Ordinary hydrogen, referred to as protium (1H1, atomic mass of 1), is

the most abundant element in the universe and has one proton in the nucleus. Heavy hydrogen,

referred to as deuterium (1H2, or D, atomic mass of 2), makes up about 0.015 percent of the

hydrogen, and has one proton and one neutron in the nucleus. Radioactive hydrogen, referred to

as tritium (1H3, or T, atomic mass of 3), has one proton and two neutrons in the nucleus. Refer to

DOE-HDBK-1079-94 and the IAEA Guide on Safe Handling of Tritium for basic information on

tritium, its properties, and compounds.

2.1 Radioactive Properties

Tritium is a beta emitter. It decays to 3He by emitting a beta particle (electron) and a neutrino from

one of the neutrons in the nucleus. The energy of the beta particle varies from 0 to 18.6 kilo-

electron-volts (keV) with an average energy of 5.69 keV. For scientific purposes, the generally

accepted value for the half-life of tritium, as measured by Mound Laboratories, is 12.323 0.004

years (4500.88 1.46 days). For DOE accountability purposes, the half-life of tritium, as stated in

DOE M 474.1-2, Figure IV-2, is 12.33 +/- 0.06 years. Figure 2-1 shows the rate of decay of one

mole of tritium over six half-lives.