Tritium Purification, Stripping and Recovery Processes

DOE-HDBK-6004-99

The TCAP offers improved operating efficiency and a more compact process package with no

sacrifice in separative capacity. It has replaced thermal diffusion and cryogenic distillation in modern

applications. TCAP is a metal hydride bed using Pd/K (palladium-coated kieselguhr) that is

thermally-cycled to separate tritium from H2 and D2 isotopes.

The isotopes removed from the TCAP process may be stored separately on LANA storage beds for

later use.

Tritium Purification, Stripping and Recovery Processes

Purification Process

The fusion machine will transfer some of its burned and unburned fuel gas to the tritium systems for

purification and storage. The tritium purification process will recover tritium and deuterium isotopes

by processing fuel gas through a Pd diffuser to separate tritium and deuterium from other gases. The

tritium and deuterium mixture then proceeds through a separation process such as TCAP which

separates tritium from deuterium. Separated tritium and deuterium gases go to separate storage

facilities such as LANA metal hydride storage beds.

Stripping and Recovery Processes

The tritium system will also recover the small amounts of tritium that inevitably leak from the primary

or secondary confinement. The recovery of leaked tritium involves use of a "stripper" system and

a recovery process. The stripper consists of a oxidizer-reactor , a pumping system, and zeolite beds

(Z-beds). The oxidizer-reactor incinerates elemental hydrogen isotopes to form oxides of these

isotopes (water vapors: H2O, D2O, etc.).

The recovery system will regenerate the zeolite beds and store the hydrogen isotopes prior to transfer

to the purification process. A typical system consists of magnesium or uranium beds, a pumping

system, and tanks. The magnesium or uranium beds break the hydrogen isotope oxides into O2 and

H2, D2 and T2.

The nitrogen (or inert gas) atmosphere of secondary confinement flows through the oxidizer-reactor

and any hydrogen isotopes convert to oxides (water vapors). The gases then flow through the zeolite

beds which absorb the water vapors. As a zeolite bed approaches water saturation, it goes off-line

and another (regenerated) zeolite bed comes on-line. The zeolite bed saturated with water vapors

undergoes regeneration which involves heating to drive off the water vapors. The water vapors pump

to the uranium bed which breaks the water into elemental gases. Hydrogen elemental isotopes go to

a separation process which recovers tritium for storage.

Past practices used a system of three strippers (primary, secondary, and purge systems) and one

recovery process to augment confinement and recovery of tritium.

The secondary confinement' nitrogen or inert gas atmosphere cycles to and from the primary stripper

systems which remove any tritium that might leak from primary confinement. The secondary stripper

is available should secondary confinement accumulate a significant tritium concentration from leaks

or maintenance work.