Answer to Question #9107 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
I reviewed the material on radionuclides in production brine at the Web site that you provided, which is New York State’s Draft Supplemental Generic Environmental Impact Statement on the Oil, Gas and Solution Mining Regulatory Program (DSGEIS). I also reviewed a report titled “An Investigation of Naturally Occurring Radioactive Materials (NORM) in Oil and Gas Wells in New York State” (Norm Report).
Radium-226 (226Ra) and radium-228 (228Ra) are of primary concern because these radionuclides can be present in high concentrations in brines, due to their relatively high solubility in saline waters, and can accumulate in oil and gas production equipment and in wastes. Most of the concentrations of radium isotopes listed Appendix 13 of the DSGEIS were comparable with those in Investigation of NORM Report, although some were higher. Consequently the conclusions of the NORM Report should be applicable to the situation. The NORM Report states that:
“The wastes from oil and gas drilling operations may contain low concentrations of elevated NORM. Of these wastes, the highest concentrations of radium were found in brines. To determine if disposal methods of these wastes may be of concern to the general public, the BPR used USDOE’s RESRAD modeling program. The modeling showed that the most common method of brine disposal in New York State, spreading it on the roads to control ice and snow, does not present significant doses to the public. This is true even if it is assumed that all brines contain the highest concentration of radioactivity detected. The resulting dose from this worst-case scenario was estimated at slightly less than 3 mR/year - well below the 10 mR/year standard presented in TAGM 4003 (1993)*. RESRAD modeling also showed that abandoned sludge and sediment pits (an unauthorized practice that nevertheless occurs) do not pose any significant dose to the public. While NORM-contaminated equipment has been a concern in North Sea oil well drilling, the results of this investigation show that NORM contamination of New York State equipment is insignificant. New York State well drilling equipment and wastes do not constitute a health risk for the State’s residents nor present a potential degradation of the
*TAGM 4003 (1993) Cleanup Guideline for Soils Contaminated with Radioactive Materials Technical Administrative Guidance Memorandum 4003, Division of Hazardous Substances Regulation, New York State Department of Environmental Conservation. Note: DSHM-RAD-05-01 is the new name for TAGM
However you have raised a concern about employees being exposed during processing of this waste water to recover fresh water. This would be an occupational situation. In my opinion, the operator of any facility processing brine with radium concentrations at levels noted in the DSGEIS and the NORM Report should perform a radiological assessment of the facility. The assessment would determine if any exposures could occur to employees, either from direct radiation or from inhalation or ingestion of radiological materials, and estimate the magnitude of any possible exposures. Measurements should be made during startup and subsequent operation to determine if the estimates are accurate. Depending on the levels of exposure or potential exposure, a radiological protection program may be established, which would include employee training, written safety procedures, periodic measurements and reviews. Employees who have concerns about radiological safety should question their supervisor or the company safety officer; if not satisfied employees can directly contact the appropriate State or Federal regulatory agency. Since diffuse NORM is not regulated by the Nuclear Regulatory Commission, the appropriate Federal Agency would be the Occupational Health and Safety Administration (OSHA).
Bureau of Environmental Radiation Protection
New York State Department of
547 River Street
Flanigan Square, Room 530
Troy, NY 12180-2216
1-800-458-1158 ext. 27556
You also asked whether risks
would be increased if the concentrations of solids are increased when water
vapors are removed. The purpose of a radiological protection program is to
control risks to an acceptable level; in a well run radiological protection
program, any increases in exposure (and risk) would be addressed with increased
Tom Gesell, PhD