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)