Determining Decontamination Methods

DOE-EM-STD-5503-94

The size of the corridor depends on:

The wind direction (corridor needs to remain upwind),

Number of stations in the decontamination procedure,

The overall dimension of work control zones (i.e., Exclusion Zone, Contamination

Reduction Zone, Support Zone), and

The amount of space available at the site.

A corridor of 75 feet by 15 feet should be adequate for the most extensive decontamination.

Whenever possible, it should be a straight path.

The CRC boundaries should be conspicuously marked, with entry and exit restricted. The far

end is the Hotline--the boundary between the Exclusion Zone and the Contamination Reduction

Zone. Personnel and equipment exiting the Exclusion Zone should go through the designated

CRC. Anyone in the CRC should be wearing the appropriate level of protection designated for

the decontamination crew.

Protective clothing, respirators, monitoring equipment, sampling supplies, and other equipment

should be maintained in the support area outside of the CRC. Personnel don their protective

equipment away from the CRC and enter the Exclusion Zone through a separate access control

point at the Hotline. Appendix F recommends the decontamination layouts, procedures, and

equipment needed for PPE Levels A through C.

10.4. DETERMINING DECONTAMINATION METHODS

The need for, and extent of decontamination depends upon the reason for an employee leaving

the Exclusion Zone/Radiological Area. A worker leaving the Exclusion Zone/Radiological Area

to pick up or drop off tools or instruments and immediately returning may not require full

decontamination. A worker leaving to get a new air cylinder or change a respirator or canisters,

however, would require some degree of decontamination. The time required for personnel

decontamination should be ascertained and incorporated into the scheduling of site activities.

Individuals departing the CRC to the Support Zone should be thoroughly decontaminated.

Personnel wearing a self-contained breathing apparatus should leave the work area with

sufficient air to walk to the CRC and go through decontamination.

A flow chart for evaluating safety and health aspects of a decontamination method is depicted in

Figure 10-2. Once decontamination procedures have been established, all personnel requiring

decontamination should be given precise instructions and should practice moving through the

decontamination line.

10-3