(a) No licensee may possess, receive, use, or transfer licensed radioactive material in such a manner as to cause contamination of soil or vegetation in unrestricted areas that causes a member of the public to receive a total effective dose equivalent in excess of 25 millirem (mrem)/year from all pathways (excluding radium and its decay products) and to the extent that the contamination exceeds the background level by more than:
  (1) for radium-226 or radium-228 in soil, the following limits, based on dry weight, averaged over any 100 square meters of area:
    (A) 5 picocuries/gram (pCi/g), averaged over the first 15 centimeters of soil below the surface;
    (B) 15 pCi/g, averaged over each 15-centimeter thick layer of soil below the first 15 centimeters below the surface; and
  (2) for radium-226 or radium-228 in vegetation, 5 pCi/g, based on dry weight.
(b) Regardless of the limits set forth in subsection (a) of this section, each licensee shall make every reasonable effort to maintain any contamination of soil or vegetation as low as is reasonably achievable.
(c) Licensees shall, to the extent practical, conduct operations to minimize the introduction of residual radioactivity into the site, including the subsurface in accordance with the existing radiation protection requirements in §336.304 of this title (relating to Radiation Protection Programs) and radiological criteria for license termination in Subchapter G of this chapter (relating to Decommissioning Standards). If contamination caused by the licensee is detected in an unrestricted area, the licensee shall decontaminate any unrestricted area which is contaminated above the limits specified in subsection (a) of this section.

Source Note: The provisions of this §336.356 adopted to be effective June 5, 1997, 22 TexReg 4588; amended to be effective September 3, 1998, 23 TexReg 8837; amended to be effective November 8, 2018, 43 TexReg 7357