Strategic Initiatives

The United States Department of Energy has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation surveillance monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the United States Department of Energy and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis. These programs are used to accurately track and assess doses delivered to Marshall Islanders from exposure to residual fallout contamination in the local environment. The key residual fallout radionuclides of radiological concern include fission products, such as cesium-137 and strontium-90, and long-lived alpha emitting radionuclides including plutonium-239, plutonium-240 and americium-241. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands (Figure 1). These facilities are operated and maintained by Marshallese technicians with scientists from the Lawrence Livermore National Laboratory providing on-going technical support services. The concentration of cesium-137 in soils from the northern Marshall Islands is significantly elevated over that expected from global fallout deposition and may enter the body of local residents through ingestion of locally grown foods. Whole-body counting provides a direct measure of internally deposited cesium-137 and is a very reliable method for assessing the internal dose contribution from ingestion of cesium-137.

We have also developed a state-of-the-art measurement technology in support of the Marshall Islands plutonium urinalysis (bioassay) program. Bioassay samples are collected by locally trained technicians under controlled conditions and returned to the United States for analysis of plutonium isotopes by Accelerator Mass Spectrometry (AMS). High-quality bioassay measurements based on AMS are providing more reliable and accurate baseline measurements, and could potentially be used track and assess intakes of plutonium associated with resettlement activities in the northern Marshall Islands.

Site specific environmental surveys are also conducted to determine the fate and transport of fallout radionuclides in the environment or simply to verify the effects of cleanup programs. The general aim of the environmental studies program is to develop fundamental scientific data on the behavior of key radionuclides in the environment. The data and information developed from these studies will ultimately be used to develop more reliable dose assessments for resettlement taking into account future change in radiological conditions. This information is essential in helping determine the most appropriate measures for cleanup and in assessing the impacts of changes in life-style, diet, and land-use on radionuclide uptake and dose. Together, the individual and environmental radiological surveillance programs in the Marshall Islands are helping meet the informational needs of the United States Department of Energy and the Republic of the Marshall Islands. Our mission is to provide high quality measurement data and reliable dose assessments, and to build a strong technical and scientific foundation to help sustain resettlement of affected atolls. Perhaps most importantly, the recently established individual radiological surveillance programs provide atoll population groups with an unprecedented level of radiation protection monitoring where for the first time, local resources are being made able to monitor resettled and resettling populations on a more permanent basis.

This web site provides an overview of the individual radiological surveillance programs currently being employed in the Marshall Islands along with a full disclosure of verified measurement data. A feature of this web site is a provision whereby users are able to calculate and track radiation doses delivered to program volunteers based on de-identified measurement data.

Figure 1:

Picture of the newly constructed Enewetak Radiological Laboratory on Enewetak Island. View related publication, UCRL-JC-147325 (Bell et al., 2002).