United States Nuclear Regulatory Commission - Protecting People and the Environment

Redefinition of Restricted Area Boundaries to Exclude an Area to be used for Residential Quarters

HPPOS-251 PDR-9208170087

See the memorandum with enclosure from L. J. Cunningham to R. W. Cooper (and others) dated July 6, 1992. This memo states that a licensee may allow residential quarters in areas originally defined as restricted after the area has been redefined as unrestricted. The health physics positions is written in the context of 10 CFR 20.3, 20.105, and 20.106, but it also applies to the “new” 10 CFR Part 20, Sections 20.1003, 20.1301, and 20.1302.

The boundaries between restricted areas and unrestricted areas are defined by licensees. A nuclear power reactor had defined the boundaries of its restricted area in plant procedures and the area was bounded by a security fence. When it appeared that some plant workers might go out on strike, the plant management considered moving trailers inside the fenced area for use as temporary residential quarters for managers during the strike. A question arose whether the contemplated use of trailers within the fenced area would be consistent with NRC requirements. In more general terms, once a licensee has established the boundaries of a restricted area as defined in 10 CFR 20.3, may the licensee allow residential quarters within that area without violating the requirements of 10 CFR Part 20? 10 CFR 20.3 includes the following definitions for restricted and unrestricted areas. [Note: Equivalent definitions for "restricted area" and "unrestricted area" are found in “new” 10 CFR 20.1003.] Restricted area means any area access to which is controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials. “Restricted area” shall not include any areas used as residential quarters, although a separate room or rooms in a residential building may be set apart as a restricted area. Unrestricted area means any area access to which is not controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials and any area used for residential quarters.

The answer is that the licensee may allow residential quarters within the area in question if:

  1. The licensee first redefines the boundaries of the restricted area to exclude the area to be used for residential quarters.

  2. The licensee ensures that the radiation levels and concentrations of radioactive material in the area used for residential quarters meet the requirements of 10 CFR 20.105 and 20.106, respectively, for unrestricted areas. [Note: Equivalent requirements are found in “new” 10 CFR 20.1301 and 20.1302.]

When redefining the boundaries of a restricted area to allow residential quarters within an area, licensees need to ensure that regulatory requirements will be met for the newly-created unrestricted area by making appropriate revisions or additions to their procedures. Topics to be considered in meeting these requirements may include instructions to workers concerning the residential quarters; access control; monitoring individuals for contamination before they enter the unrestricted area; monitoring materials for contamination within the unrestricted area; and provisions for individuals residing in the residential quarters in emergencies.

Regulatory references: 10 CFR 20.3, 10 CFR 20.105, 10 CFR

20.106, 10 CFR 20.1003, 10 CFR 20.1301, 10 CFR 20.1302

Subject codes: 1.7, 4.3, 4.4, 12.8

Applicability: Reactors

Page Last Reviewed/Updated Thursday, March 29, 2012