Naturally occurring radioactive materials are exempt from the provisions of OAR 345-050-0006 if the Council or the Department of Energy finds that accumulation of material cannot result in exposures exceeding 500 millirem of external gamma radiation per year, nor in the release of effluents to air and water in annual average concentrations exceeding the values in Table 3. The Council or the Department shall base its finding on an evaluation of potential radiation exposures and effluent releases performed under the following conditions:

1. (1) The evaluation considers material in the form in which it exists when it is removed from the users' equipment, systems, or settling ponds prior to any dilution or remedial action designed to reduce radiation levels.
2. (2) The evaluation does not consider any ameliorating effects of land use restrictions, maintenance operations, or cover material at the disposal site.
3. (3) The evaluation covers accumulations of material over the reasonably projected period of waste generation.
4. (4) The evaluation bases external gamma radiation exposures on actual measurement with allowance for the degree of equilibrium and for self-shielding.

5. (5) The evaluation uses the following premises in computing radon concentrations in the air above a disposal site containing radium-226:

   1. (a) The evaluation assumes that any house built on ground contaminated with radium-226 has an 8-foot high ceiling on the first floor, has one complete air change per hour, and has a foundation constructed so as to meet the Structural Specialty Code (State of Oregon Uniform Building Code) in effect on March 1, 1979 without allowance for any special construction or treatments designed to reduce radon diffusion into the structure;

   2. (b) The evaluation bases the relation between radon-emanation rate and radium concentration upon experimental measurements on material intended for disposal.

      [ED. NOTE: Tables referenced are available from the agency.]

      [Publications: Publications referenced are available from the agency.]

Statutory/Other Authority

ORS 469.470

Statutes/Other Implemented

ORS 469.525

History

EFSC 1-2007, f. & cert. ef. 5-15-07
EFSC 1-1999, f. & cert. ef. 3-5-99
EFSC 9-1978, f. 12-28-78, ef. 3-1-79