Release Criteria - STD-1128-98master0113

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

window longer. To ensure that low levels of contamination can be detected, it is

necessary that a maximum scan speed be mandated and that this speed be

implemented during field measurements. As noted above, a typical scan speed for

instruments in current use is 2 in./s (5 cm/s). However, the scan speed for a

specific application should consider the instrument, probe, guideline value, and

confidence level desired. The MARSSIM (NRC 1996) contains guidance for

determination of scan rates. It 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 (DOE, 1999a).

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.

Nonradioactive material can be released without an instrument survey if its documented

history ensures

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