Conversion of Elemental Tritium to Tritium Oxide

DOE-HDBK-6004-99

Where the safety analysis evaluates fires as design basis accidents, design should provide for fire

detection and suppression systems having appropriate capacity and capability to minimize adverse

effects of fires on safety-class systems, structures and components. Rupture or inadvertent operation

of fire suppression systems should not significantly impair the safety function of tritium systems,

structures and components.

Fire suppression systems should emphasize use of dry chemical or gas suppressants. Because of the

natural affinity of tritium for water and the increased biological hazard of tritiated water, the use of

water as a tritium fire extinguishing agent should require a technical or economic justification.

Facilities that have the potential for introducing fire suppression water into a tritium contaminated

environment should provide a tritiated water collection system with the capacity to store the total

volume of fire suppression run-off. Design should provide for facilities to dispose of any tritiated

water in an environmentally acceptable manner.

Conversion of Elemental Tritium to Tritium Oxide

The design should include engineered features as necessary to minimize the potential for tritium

contact with ignition sources, water, moisture, hydrocarbons and other oxidizing sources. Because

oxidized tritium is a significant biological hazard, the design must reduce to a practical minimum the

unintended conversion of tritium to any oxidized form. This criterion recognizes that some tritium

cleanup systems convert elemental tritium to an oxide form with deliberate intent, to facilitate removal

from flowing gas streams.

Heat Removal

The design should provide for reliable removal of total heat loading from all confinement barriers.

Total heat loading consists of tritium decay heat and equipment energy dissipation within a barrier

and heat transfer into the barrier from external energy sources.

System Cleaning

The design should provide for cleaning of tritium systems before and after installation. Tritium

systems should be able to withstand vacuum conditions necessary for cleaning purposes. Once

tritium has contaminated the primary confinement, only limited cleaning is permissible for tritium-

wetted surfaces.

Tests and Inspections

The design should provide for periodic tests and inspections of structures, systems and components

related to the intended safety function. The tests and inspections should assess structural integrity,

hydrogen embrittlement, leaktightness and other parameters related to the safety function.

The design should provide for and operations should have an appropriate materials surveillance

program.

If the design does not permit periodic inspections and tests in accordance with applicable codes,

particularly for systems contaminated with tritium, the safety analysis should develop and prescribe

an acceptable testing program. The facility authorization basis should include the test and inspection

program.