For periods of eight continuous hours or less, the area is under the continuous observation and control of an
individual knowledgeable of, and empowered to implement, required access and exposure control measures
Provisions for labeling radioactive material are specified in Chapter 4.
237 Posting Underground Radioactive Material Areas
Underground radioactive material areas should be established to indicate the presence of underground items that
contain radioactive materials, such as pipelines, radioactive cribs, covered ponds, covered ditches, catch tanks,
inactive burial grounds, and sites of known, covered, unplanned releases (spills). Underground radioactive material
areas need not be posted if physical or administrative controls are implemented to ensure appropriate radiological
controls are established prior to excavating, penetrating, or otherwise disturbing underground radioactive materials.
Underground radioactive material areas should be posted "UNDERGROUND RADIOACTIVE MATERIAL."
Posting should include instructions or special warnings to workers such as "Consult With Radiological Control
Organization Before Digging" or "Subsurface Contamination Exists." The posting should meet the applicable
requirements of Article 231.
Underground radioactive material areas may be located outside controlled areas unless access is likely to result in
individual doses (total effective dose equivalent) greater than 100 millirem in a year from underground radioactive
Underground radioactive material areas are exempt from the entry and exit requirements of Chapter 3 when access
is not likely to result in individual doses greater than 100 millirem in a year. Article 333.1 provides entry
provisions for instances in which access is likely to result in individual doses greater than 100 millirem in a year.
238 Posting Soil Contamination Areas
For areas with contaminated soil that is not releasable in accordance with DOE's environmental protection
standards, a soil contamination area should be established that is posted in accordance with the requirements in
Article 231.1 through 231.8. Posting should include the words "Caution, Soil Contamination Area" and instructions
or special warnings to workers, such as "Consult With Radiological Control Organization Before Digging" or
"Subsurface Contamination Exists."
Soil contamination areas may be located outside controlled areas if exposure to the material in the area is not likely
to cause any individual to receive a total effective dose equivalent in excess of 100 millirem in a year.
If the contamination levels in the area exceed the values provided in Table 2-2 (as evidenced by the likelihood of
tracking contamination out of the area at levels exceeding these values), then the area is a contamination area or
high contamination area and shall be posted in accordance with Article 235 [see 835.2(a), contamination area and
high contamination area and 835.603(d) and (e)].