Valve seals and gaskets should be resistant to radiation damage.
Straight-through valves generally should be used to simplify
maintenance and minimize particle traps.
Valves should be designed to operate in the stem-up orientation, which
would limit potential leakage when the pipe is unpressurized. Valves and
flanges should be located to minimize the consequences of
contamination from leaks.
Generally, process solutions should have primary and secondary
confinement. However, in rare instances where process solutions are
allowed to flow outside of confinement, they should flow only by gravity
and the pressure head should be limited to an equivalent of about 10 feet
The corrosion resistance of the primary block valve and/or check valve
and all associated piping in the in-cell and/or contaminated areas should
The use of pumps in contaminated piping systems should be avoided to
and to reduce the maintenance requirements associated with pumping.
The use of gravity flow, jets, vacuum, or airlifts is a suitable alternative.
Vacuum transfers are preferred. If jets or airlift transfers are used, an
adequate waste-air cleanup system should be provided.
Floors should be designed in accordance with code requirements
considering the maximum loads anticipated.
In-process storage should not be permitted; however, temporary storage
of the product in the process area until it can be taken to an appropriate
storage area should be permitted.
Storage facilities in the process areas should be designed to prevent the
exposure of operating personnel and to meet the requirements for
security and safeguards.
Provisions should be made to accommodate the shielding of all items in
the process area. All structures (e.g., floors, walls, and glove boxes) may
require additional shielding during the lifetime of the facility because of
increased throughput or higher radiation levels of the material being