Access Control

DOE-HDBK-1184-2004

to surfaces and/or to the matrix below such surfaces. This guidance is applicable to

efforts to evaluate the total (fixed plus removable) STC activity levels, which are

used as a basis for radioactive material area posting.

Circumstances may arise in which it is desirable to establish a controlled area due

solely to the presence of STCs. 10 CFR Part 835 requires that controlled areas be

established whenever radiological or radioactive material areas are present, but

does not establish specific criteria that define the controlled area boundaries.

Controlled area postings should be established to enclose any area where it is likely

that personnel activities in the area will result in the spread of:

STC removable surface contamination beyond the current area boundaries at

levels exceeding one tenth of the levels specified in Appendix D of 10 CFR 835;

STC airborne radioactivity beyond the current area boundaries at levels

exceeding one tenth of the airborne concentration value specified in Sections

5.2.4.2 and 5.2.5.1 of this handbook.

The controlled area boundaries should be established so that all of the affected

area is encompassed, and area monitoring should be performed on a periodic basis

to verify the adequacy of the boundaries. The area boundaries should be altered

as necessary, based on the results of the area monitoring.

It is often desirable to restrict access to STC-contaminated areas, to specified

individuals or workgroups so as to limit the scope of the STC dose assessment

program. If this has been done, posting for STC-contaminated areas should

provide additional information that will allow individuals to identify the area as one

affected by STCs, and to take appropriate action to avoid or facilitate entry, as

appropriate.

6.2.6

Access Control

NOTE: The access control measures discussed in this section are in addition to the

radiation safety training measures discussed in Section 6.2.9 of this

handbook.

Access control measures may be necessary to control individual access to areas

where STC surface contamination or airborne radioactivity is present. 10 CFR Part

835 requires entry control measures for all radiological areas. The established

controls should be appropriate for the radiological conditions in the area and the

planned activities, some of which may cause changes in the radiological conditions

or in the conditions (e.g., relative position, exposure time, contaminant

resuspension) under which individuals are exposed. DOE has provided guidance in

the RCS.

For low levels of STC contamination (e.g., surface contamination levels less than

the 10 CFR 835 Appendix D values; airborne radioactivity levels resulting in an

intake less than 12 ACV-hours in a week [0.3 times the ACV values]), only

rudimentary entry control measures are necessary. These measures may include

basic engineering and administrative controls.