also suggests that an empirical method be used to verify scan rates. The
equipment and method used in this determination may be incorporated into
training for survey personnel to enhance their survey skills.
4.2.5 Release Criteria
The release of material from radiological areas shall be performed according to 10
CFR 835.1101. In these areas, material and equipment should be treated as
radioactive material and should not be released from radiological areas to controlled
areas if either of the following conditions exist:
-- Measurements of accessible surfaces show that either the total or removable
contamination levels exceed the values specified in Table 4.1
-- Prior use suggests that the contamination levels on the inaccessible surfaces are
likely to exceed the values specified in Table 4.1.
Wire rope and electronic gear with cooling fans are examples of equipment that are
difficult to survey and require special procedures to be released from contaminated
and airborne radioactivity areas. Additional release criteria can be found in Section 4
of the DOE standard, Radiological Control, Ch. 1. (DOE, 2004).
It may be noted that Appendix D of 10 CFR 835 allows that surface radioactivity
values be averaged over 1 m2 provided that the activity in any 100 cm2 is not more
than three times the specified value.
The material release methodology has four main components: material evaluation,
scan survey for fixed contamination, large-area wipe survey for removable
contamination (described above), and statistical survey for fixed contamination. The
material process involves consideration of the previous known uses of the material,
as well as typical uses and the environment in which the material was used. Material
evaluation places the material into one of two categories: not potentially
contaminated or potentially contaminated.
Non-radioactive material can be released without an instrument survey if its
documented history ensures
-- That it has never been used or stored in an area controlled for contamination
purposes (i.e., a Contamination Area, High Contamination Area, or Airborne
-- That it has never come into contact with unsealed radioactive material
-- That it has not been stored or used in a Radiological Buffer Area (RBA)
surrounding a Contamination Area, High Contamination Area, or Airborne