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
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
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
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 asphalt or vinyl tile because it is more easily cleaned. If the
floor needs resurfacing, it is preferable to overlay new flooring material rather than
remove the old material and expose the underlying floor.