Equipment Selection and Location

DOE-HDBK-1132-99

joints and crevices should be caulked or sealed to prevent the accumulation of

contaminated materials at inaccessible locations. The use of hazardous

material should be minimized to preclude the generation of mixed waste.

The following sections address design features that should be considered for

radioactive and hazardous materials processing and handling facilities.

Equipment Selection and Location . Equipment and configurations should be

2.12.2

selected that preclude, to the extent practicable, the accumulation of

radioactive or other hazardous materials at curves, turns, and joints in the

piping, especially in hard-to-reach or inaccessible locations. The design should

avoid the use of built-in crud traps, such as flanged couplings, dead legs, etc.

Construction materials and surface finishes should be considered to minimize

porosity, crevices, rough machine marks, etc., to limit the possibility of tightly

adherent contamination and to facilitate ease of decontamination. An example

of this is electro-polished stainless steel liners.

Localized liquid transfer systems should be considered that avoid long runs of

contaminated piping to the extent practical, with special attention to the design

features necessary to maintain the integrity of joints in buried pipelines. Local

processing (solidification) of liquid wastes should be considered when

designing piping and liquid disposal systems.

The design should provide for full draining of contaminated piping systems by

including the installation of low-point drains, pump drains, tank vent systems,

and drain systems, and the elimination of dead legs between valves in system

designs. A valuable tool in this design effort would be a 3-D computer-assisted

design and drafting system to confirm that all low points can be drained and

that dead legs are not designed into the system.

The design should allow access for easier dismantlement, cut-up

(segmentation), removal, and packaging of contaminated equipment from the

facility. Modular process equipment packages lend themselves well to this

approach. The design should minimize pipe spring due to residual stress.

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