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Declassification of Today's Highly Enriched Uranium Inventory at the Savannah River Site near Aiken, South Carolina

U.S. Department of Energy, Office of the Press Secretary, Washington, DC 20585


Declassification of Today's Highly Enriched Uranium Inventory at the Savannah River Site near Aiken, South Carolina

Table of Contents

Specifically
Background
Benefits
Who Are the Key Stakeholders?
Contact
Questions and Answers

The Department of Energy has declassified the total highly enriched uranium inventory at the Savannah River Site in Aiken, South Carolina. Highly enriched uranium is defined as uranium having an enrichment above 20 percent of the fissionable isotope uranium-235.

Specifically

Background

Benefits

Who Are the Key Stakeholders?

Contact

U.S. Department of Energy
Office of Public Affairs
Contact: Sam Grizzle
(202) 586-5806


U.S. Department of Energy, Office of the Press Secretary, Washington, DC 20585


QUESTIONS AND ANSWERS

Q. Are releases of radiation and radioactive materials, such as uranium and tritium from operations at the Savannah River Site, a health hazard to the workers or the public?

A. The Department of Energy is addressing the question of health hazards from exposures to materials, such as tritium and uranium, by sponsoring a comprehensive package of health studies of Savannah River Site workers and community residents. They include the following:

A program for surveillance of illness among Savannah River Site workers that systematically collects and analyzes data on worker absences began in 1992. This program will help identify patterns of illness and injury so that specific workplace exposures can be better monitored and controlled.

The medical surveillance program of Savannah River Site examines workers who have been identified by their unique exposures or occupations. Medical surveillance activities are being expanded at all Department of Energy sites. The program will be tailored to specific site needs such as the identification of early signs of organ damage from heavy metals such as uranium.

A Department of Energy mortality study of 9,860 white males was published in 1988. These men were employed for 30 days or more before 1975 and were followed through 1980. The study did not contain information on exposure to ionizing radiation. Eleven of the 43 categories of cause of death among hourly workers had statistically significant fewer deaths than expected. There were 13 of the 43 categories among salaried workers with fewer than the expected number of deaths. The only statistically significant excess mortality rate was for leukemia among hourly workers first hired before 1955 and employed between 5-15 years. Information on ionizing radiation is now available and is the basis of a second study that will be completed in 1994. The preliminary findings from this second study are being reviewed by the National Institute for Occupational Safety and Health who currently manage the Department of Energy analytic epidemiology studies.

During calendar year 1993, approximately 1000 workers and visitors were monitored at the Savannah River Site as part of the internal dosimetry program. About 500 workers have positive tritium (H-3) doses above the minimum detectable dose of 1 mrem committed effective dose equivalent (50 year committed effective dose equivalent.) The range of these positives was from 1 mrem to 30 mrem committed effective dose equivalent. The collective dose was 5-6 rem committed effective dose equivalent. For H-3 the annual effective dose equivalent is the same as committed effective dose equivalent. Six of these workers received plutonium doses above the minimum detectable dose of 10 mrem committed effective dose equivalent. Two of these positives ranged from 10-100 mrem and the other four fell between 100-208 mrem committed effective dose equivalent. The highest dose in recent years is one individual who received an uptake of plutonium in 1991 of 15.0 rem committed effective dose equivalent. This is quite unusual for the site but the potential does exist there due to the old design of some of the facilities. Potential for uranium exposures are practically nil at Savannah River Site.

Since startup of the first reactor at Savannah River Site in December 1953, internal dose has been followed. The total collective dose from plutonium exposures for the some 70,000 people monitored over these years at Savannah River Site approximately 70,000 rem collective committed effective dose equivalent, an average of about 1 rem collective committed effective dose equivalent dose per each worker. Total dose to Savannah River Site workers has dropped significantly in recent years. The total collective dose in 1993 was 261 mrem committed effective dose equivalent, as compared to collective doses of 1000-1200 mrem committed effective dose equivalent in the production years of a decade ago.

In previous years of the Savannah River Site production activity, H-3 doses averaged about 5 percent of the total Savannah River Site worker dose. In recent years, tritium dose has dropped to 2-3 percent of the total Savannah River Site worker dose. No Savannah River Site worker has received a tritium dose in excess of 100 mrem in the past several years.

Doses from intakes of actinides at Savannah River Site have averaged about 6.5 percent of the total occupational radiation dose received by Savannah River Site workers since site operations began. Most of the highest individual doses to Savannah River Site workers, however, are due to intakes of actinides.

The first phase of a dose reconstruction study is being performed by the Centers for Disease Control and Prevention at the Savannah River Site, and it will be completed this year. This is a document review to help describe the historical operations of the site and identify the materials released to the environment.

In another program, the Medical University of South Carolina, under a State Health Agreement, has established a cancer surveillance system in the region of the Site. The recording of cancer cases in this system can be used to detect unusual patterns or clusters of cancer near the Site.

Q. Why wasn't the uranium separated and stabilized? The reports say that some uranium fuel elements are starting to corrode.

A. The facilities needed for such separation and stabilization were shut down for safety reasons. The Department and the Savannah River Site are presently studying all possible methods for disposition of the irradiated elements. Some corrective actions have been taken to address vulnerabilities related to spent nuclear fuel.

Q. If Savannah River reactors are shut down, why not shut down the whole plant?

A. Facilities are still needed to purify tritium, care for materials on the site, and clean up buildings and other facilities even though the reactors are shut down.

Q. Where is the highly enriched uranium stored at Savannah River and how do you keep it safe?

A. Onsite reviews indicate the enriched uranium storage is safe. Various forms are stored in vaults, spent fuel basins, and other locations, as appropriate. Many measures are in place to maintain safe, secure storage, such as routine surveillance and monitoring.


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