Design Features - STD-1128-98master0264

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

Investigation Manual (MARSSIM) has been published (DOE, 2000b). It provides detailed

techniques applicable to the D&D of DOE facilities.

10.2 DESIGN FEATURES

Design of the facility should allow easy D&D of equipment and materials. Details on designing

facilities for ease of decommissioning are discussed in the following sections. 10 CFR 835.1002

and Appendix C of this document provide additional guidance on facility design.

10.2.1 Building Materials

In general, the design features that aid in contamination control during operation also

facilitate decommissioning. The inclusion of all the building materials suggested in this

section may be cost-prohibitive, but they should be considered if the budget allows. The

maintenance procedures that are used during operation are also important in controlling the

spread of contamination to clean areas and, therefore, they facilitate decommissioning, too.

Less permeable building materials are more easily decontaminated. Any concrete with

uncoated surfaces that comes in contact with plutonium solutions or plutonium-

contaminated air will require surface removal and disposal as radioactive waste at the end of

its life. If there are cracks through which contaminated solutions have penetrated, the entire

structure may need to be disposed of as radioactive waste.

Metal surfaces may also require decontamination. In general, the more highly polished the

surface, the easier it will be to decontaminate. If feasible, all stainless steel that will come

into contact with plutonium should be electropolished before being placed into service. If

high-efficiency particulate air (HEPA) filtration has failed at any time during facility

operation, roofs may require decontamination. Metal roofs are easiest to decontaminate, but

even these may contribute to the volume of radioactive waste unless unusual measures are

taken to clean them. Built-up and composition roofs will be difficult to clean to unrestricted

release levels.

Interior surfaces are most easily cleaned if they were completely primed and painted before

the introduction of radioactive materials into the facility. If interior surfaces are repainted

during operation, their disposal as clean waste is likely to require removal of the paint.

However, if the paint has deteriorated, cleaning for unrestricted use may be as difficult as if

the material had never been painted. Wood will almost certainly become contaminated, as

will plasterboard and other such materials.

Floor surfaces are likely to be a problem. Concrete should be well sealed and covered with a

protective surface. Single sheet, vinyl flooring with heat-sealed seams is preferable to

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