Segmented Tritium Systems

DOE-HDBK-6004-99

additional guidance for design of confinement barriers. RG 1.140 provides guidance for design,

testing and maintenance for tritium removal systems.

Segmented Tritium Systems

Tritium systems design should provide for segmentation of the tritium inventory to make acceptable

the amount of tritium releasable in a single event. Design should provide for isolation of each

segmented volume using valves or piping blanks. Check valves and other one-way valves are not

acceptable as isolation devices.

Release of tritium from the single largest segmented volume should not result in exceeding prescribed

dose limits or other unacceptable consequences.

Segmentation may be accomplished by either

1. Utilization of processes or devices with small inventory, or

2. Separation of the tritium inventory into isolable volumes, or

3. Storage of tritium in an immobile condition relative to the single event (e.g., metal hydride beds).

Protection For Natural Phenomena

For the tritium systems that are safety class, including structures and components, design should

provide robustness to withstand the effects of design basis natural phenomena such as earthquake,

tornado, hurricane, flood tsunami, seiche, etc., without loss of safety function. The design should

also provide for protection of safety-class equipment and systems from potential failure of non-safety-

class hardware during natural phenomena events. If protection includes isolation of safety-class

systems, the equipment, instruments and electrical systems that provide for the isolation should be

capable of withstanding the effects of design basis natural phenomena without failure of function and

should be fail-safe in the event of power loss or failure within electrical systems.

Protection from Environmental Conditions and Missiles

For the tritium systems, including structures and components, that are safety class, design should

provide robustness to accommodate the effects of environmental conditions of normal operations,

maintenance, testing and postulated accidents without loss of safety function. Safety-class tritium

systems should have robustness or protection to withstand dynamic effects of a missile, pipe whip,

or runaway plasma that may result from equipment failures and from events outside the tritium

systems if the safety analysis evaluates these as design basis accidents.

Fire Protection

The design should minimize the probability and consequences of tritium fires or explosions. Because

fire oxidizes elemental tritium to tritium oxide, a form with a much greater biological hazard, design

should place high priority on preventing fires. The design should use noncombustible or fire resistant

materials to the greatest practical extent throughout the tritium systems.