Access Control to High Radiation Areas at Nuclear Power Plants
See the memorandum from L. J. Cunningham to J. H. Joyner (and others) dated August 2, 1991.
A step-off pad (SOP) at the access point to a high radiation area does not constitute a barricade as required by Technical Specifications. The health physics position was written in the context of 10 CFR 20.203, but it also applies to "new" 10 CFR 20.1601.
Most Technical Specifications, in Section 6.12, "High Radiation Area," require that each area in which the dose rate is between 100 and 1000 mrem/hr be "barricaded and conspicuously posted as a high radiation area ...." A Region I licensee instituted a policy in which the "barricade" consists of a SOP at the access to the high radiation area. The area is roped off and posted but the entry at the SOP is not roped off. The licensee maintained that the SOP satisfies the barricading requirement in Technical Specifications. This policy is used only in situations where the area is a contamination area as well as a high radiation area.
Technical Specifications with this barricade and posting requirement provide a method for control of high radiation areas that is an alternative to the method specified in 10 CFR 20.203 (c) (2) [or 10 CFR 20.1601 (a)]. Although not explicitly stated, these controls are designed to prevent inadvertent entry into the area. Controls specified in Technical Specifications are intended to achieve the same basic aim, namely prevention of inadvertent entry, but in a different manner from that specified in Part 20. The difference is to allow for the different nature of the sources at nuclear power plants as well as the different administrative controls and training found at such facilities.
Inadvertent entry is interpreted in this context to mean entry by an individual who is not paying sufficient attention to postings and who may walk into the high radiation area unless his or her attention is drawn to these postings. The assumption is that if an individual's attention is drawn to the postings, that individual will recognize their implications and take appropriate action. A barricade is one mechanism to accomplish this purpose. The dictionary defines a barricade as "any barrier that obstructs passage." A SOP is not a barrier to movement into the area and therefore does not qualify as a barricade required by Technical Specifications. Implicit in the requirement for the barricade is that the barricade can be partially taken down for periods of access. This is acceptable as long as the access point is attended by an individual who will prevent inadvertent / authorized access to the high radiation area.
Regulatory references: 10 CFR 20.203, 10 CFR 20.1601, Technical Specifications
Subject codes: 4.1, 4.7