United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 373: What are the minimum requirements for height

and access restrictions of barriers used to prevent entry

to locked high radiation areas HRAs) and very high

radiation areas (VHRAs) at nuclear power plants?

Answer: The NRC has prepared Regulatory Guide 8.38 that

details control measures that should be implemented for

such areas. This regulatory guide provides guidance on the

following program elements as related to control of locked

HRAs and VHRAs: management controls, procedural controls,

training, communications and physical controls.

In general, there are no prescriptive, specific minimum

height requirements for barriers preventing entry to locked

HRAs and VHRAs. It is required that physical controls

(such as barriers) provide assurance that individuals are

not gaining unauthorized access to locked HRAs. For VHRAs,

10 CFR 20.1602 requires "additional measures to ensure that

an individual is not able to gain unauthorized or

inadvertent access." The NRC staff realizes that tools

(wrenches, wire cutters, cutter torches) are readily

available in a nuclear power plant and that it is virtually

impossible to prevent determined willful circumvention of

physical barriers. However, physical controls can and

should be established so that any such willful acts are

detectable (i.e., they result in cut locks or fencing, wall

panels removed, etc). For example, the use of a fence to

prevent access to a VHRA would not satisfy the requirements

of 10 CFR 20.1602 if an individual could gain access to the

VHRA by climbing over the fence. (References: 10 CFR

20.1601, 10 CFR 20.1602)

Page Last Reviewed/Updated Thursday, March 29, 2012