Air Monitoring - doe-hdbk-1184-2004

DOE-HDBK-1184-2004

NOTE:

There is no tritium value for total surface contamination in 10 CFR 835

Appendix D. Accordingly, those provisions in 10 CFR Part 835 that apply

to surfaces with total surface c ontamination levels greater than Appendix

D levels do not apply to tritium.

The external hazard from tritium radiation is not considered to be a significant

source of radiation exposure. Accordingly, compliance with the tritium value for

removable contamination will provide an acceptable level of protection to individuals

in controlled areas. This approach is considered acceptable for most tritium

contamination.

However, there may be cases where tritium binds tightly to the matrix into which it

has diffused, and removable contamination levels are below the values in 10 CFR

Part 835. Such cases could occur when insoluble tritiated particles are fixed to a

surface or from tritium exposure to bulk quantities of metals of the types from which

insoluble metal tritides are formed. In such cases it is recommended that the

provisions in 10 CFR 835 subpart L pertaining to total surface contamination values

be applied, when the total surface contamination level exceeds 10,000 dpm/100

cm2. In addition, when performing operations on these types of tritiated materials, it

is important to assess the potential for producing airborne concentrations of

respirable ITPs, and if needed, institute radiological controls appropriate to this

hazard.

3.2.2

Air Monitoring

DOE Guide DOE G 441.1-8 (DOE 1999b), Air Monitoring, provides detailed

guidance for developing and implementing an air monitoring program. This

guidance is supplemented by that provided in the RCS (DOE 1999g) and in DOE-

STD-1121-98 (DOE 1999h), Internal Dosimetry. This guidance, combined with that

provided above for identifying areas possibly affected by STC contamination, is

applicable to the air monitoring program for STCs. Likewise, the guidance that

follows regarding identification of STCs and analysis of samples, is applicable to the

air monitoring program.

3.2.3

Identification of STCs

After collecting samples of surface contamination or airborne radioactive materials,

it is necessary to conduct radioanalyses to identify the levels of tritium (and other

radionuclides) present in the sample. Tritium analyses are most commonly

performed by liquid scintillation analysis of surface smears and air samples.

Although liquid scintillation analysis is very effective in analyzing for the presence of

tritium, this technique does not differentiate between the various forms of tritium

(HT, HTO, STCs). Thus, non-standard techniques must be used to distinguish

STCs from HT and HTO, and to distinguish among the various STC species. To

date, a rapid, simple and reliable method for identifying STCs has not yet been

developed.

In the following paragraphs, several techniques for identifying ITP species are

described. However, all of these approaches have some drawbacks. In practice,

some combination of the suggested analyses, or an entirely new approach, may be

needed to evaluate the ITP contamination levels present in the samples. Such