Release of Materials - hdbk110697

DOE-HDBK-1106-97

Radiological Contamination Control Training

for Laboratory Research

Student's Guide

APPENDIX D

RELEASE OF MATERIALS

Monitoring Techniques General

Monitoring techniques for release of materials are addressed in DOE/CH-9401 (1993). The

following techniques apply for G-M detectors (H-3 cannot be measured).

1. Surveys should be conducted in a low background area (background levels are not to

exceed 300 cpm; lower levels are preferable and in most cases achievable).

2. Direct measurement should be made prior to smear surveys.

3. Materials or equipment with inaccessible surface areas should be disassembled for

survey or the inaccessible areas evaluated for contamination with special survey

techniques or by review of process knowledge.

If potential for internal contamination cannot be adequately assessed, material may

not be released.

4. An audible response should be utilized as the principal indicator for initial detection of

5. The assigned instrument/detector efficiencies should reflect a prior evaluation of facility

wastes.

Typical efficiencies for a thin-window G-M probe.

C-14, S-35 - 10%.

P-32 - 50%.

D-1