The purpose of this time-critical removal action at the Radiation – Instruments and Flight Research (IFR), Site (Site), located at 2716 South George Washington Boulevard, Wichita, Kansas, 67210, is to protect public health or welfare or the environment by responding to the release, or substantial threat of release, of the hazardous substance radium-226 into the environment at the Site. The Site is located approximately seven miles southeast of the downtown Wichita area and causes a threat of exposure to exist for those who work and live nearby.
IFR was an aircraft instrument repair shop, which operated on the property from as early as 1963 and was granted a radioactive materials license (RML 25-R223-01) by Kansas Department of Health and Environment (KDHE) in January 1970, which is in effect and is valid until terminated. The company primarily rebuilt surplus aircraft instruments and accessories. Aircraft instruments contained radioluminescent paint that contained radium. During the rebuilding or refurbishing process the radium bearing paint was removed with solvents. Previous KDHE investigations have identified radium-226 contamination in surface soil and on interior building surfaces and equipment. KDHE reports that its Bureau of Air and Radiation (BAR) and Bureau of Environmental Remediation (BER) had historically identified points of noncompliance with BAR radiation regulations and provisions of IFR’s radioactive materials license, and eventually referred the Site to EPA for assessment of potential releases of hazardous substances.
Radioluminescent paint – a mixture of a radionuclide, usually radium-226, and a phosphor, usually zinc sulfide – was developed in the early 1900’s. The mixture was initially used on watch and clock faces and later adapted for use on instruments, most notably aircraft dials. As part of radium’s decay process, it emits an alpha particle that can excite the phosphor which eventually releases a photon. Radioluminescence makes aircraft dials, gauges and instruments “glow” and as a result they are more readily visible to the aircraft operators at night. By the 1960’s more than 75 percent of the light aircraft produced in the United States were manufactured in the Wichita area. Radium dial repair shops, such as the ones which operated at the Site, were established to upgrade and repair radium-bearing aircraft instruments. IFR engaged in the rebuilding and/or refurbishing of aircraft instruments at the Site, which involved the stripping of instruments containing radioluminescent paint. As part of this process, paint containing radium was typically stripped from the dials with solvent prior to the dials being repaired.
Radium-226 is present in the interior building and exterior soils at the Site. The removal action entailed the removal, remediation and/or excavation and off-site disposal of building materials, debris, drums, bags, equipment and soils contaminated with radium-226 at levels in excess of 5.87 picocuries per gram (pCi/g).
