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Radiochemistry Program

The Radiochemistry section was formed in August 1977 to provide environmental radioanalytical services for programs/projects of state and other governmental entities.

As an environmental radiological analytical facility, the section’s analytical parameters are focused on the naturally occurring radionuclides, i.e. the important members of the uranium-238 series and the thorium-232 series. The section routinely analyzes for: Gross-a/ß by proportional counting; U-238/234 by alpha spectroscopy; Th-230/232 by alpha spectroscopy; Ra-226 by radon emanation; Ra-228 by beta proportional counting of Ac-228 daughter; and Rn-222 in water by liquid scintillation. A gamma spectroscopy capability is maintained for the identification and quantitation of most man-made radionuclides (i.e. gamma emitters, such as Co-60, Cs-137, I-131). Due to the presence of alpha spectroscopy instrumentation, a capability for the analysis of the following transuranic nuclides Am-241, Pu-238, and Pu-(239+240) is also maintained.

Additional parameters are potentially available, depending upon the user’s needs and support that can be mustered. Users involved in non-routine programs or special projects are encouraged to consult the section supervisor to discuss their needs and available options.


History

The section's initial charge was to provide radiochemical analyses in support of the Safe Drinking Water Act’s then recent inclusion of Radionuclides as regulated parameters [41FR28401, Aug. 9, 1976]. In January of 1979, the section obtained EPA Region 6 certification for the measurement of gross alpha, gross beta, Ra-226 and Ra-228 in drinking water. This certification has been retained ever since. After the procurement of gamma spectroscopy instrumentation, and participation in that portion of the EPA proficiency program, the laboratory received, in Mar-1985, certification for that measurement as well; which has likewise been retained.

After accomplishing Safe Drinking Water Act (SDWA) certification, the section moved into non-drinking water areas and developed the capability to handle a broader range of sample media, e.g. water with sediment, soils and air filters. Requests for handling such sample media have fluctuated. During the mid-1980’s there was a program for analyzing air filters from the Grants Mineral Belt for U-238/4, Th-230, Ra-226 and Pb-210; however, that program has gone the way of uranium mining and milling. During the early 1990’s there was a project that submitted several roadside dirt samples so as to establish an occurrence baseline for several radionuclides.

We have been significantly involved in the following unique historical projects:

  • The Churchrock Uranium Mill Tailings Dam failure of ~1978.
  • Cobalt-60 in Rebar Saga of Jan-1984. (See Science, vol-223, pp1152-4, 16-Mar-1984)
  • Polonium-210 in diesel fuel episode of ~1986.
  • Revelation of contamination of a local facility with Sc-46, Ag-100m, Sb-122/124, Ir-192 & Au-198 in mid-1990.
  • A New Mexico Wellhead Survey On The Occurrence of Radon-222 At Public Water Supplies
  • Discovery of Sc-46 and Sb-124 in oil field waste sand disposal drums from southeast New Mexico in Jan-1998

Methodology

EPA 600 4-80-032

  • 900.0 Gross Alpha and Gross Beta Radioactivity in Drinking Water
  • 903.1 Radium-226 In Drinking Water Radon Emanation Technique

EPA SW-846

  • Method 9310 Gross Alpha and Gross Beta
  • Method 9315 Alpha-Emitting Radium Isotopes
  • Method 9320 Radium-228