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U.S. Department of Energy

Office of Environment, Health, Safety and Security

Office of History and Heritage Resources

Declassification of the United States Total Production of Highly Enriched Uranium

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


Declassification of the United States Total Production of Highly Enriched Uranium

Table of Contents

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

The Department of Energy has declassified the total amount of highly enriched uranium that was produced at the K-25 Site (formerly known as the Oak Ridge Gaseous Diffusion Plant) at Oak Ridge, Tennessee, and at the Portsmouth Gaseous Diffusion Plant at Portsmouth, Ohio. 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


Attachment

Total United States Highly Enriched Uranium Production (1945-1992)


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


QUESTIONS AND ANSWERS

Q. What are the disposition plans for these old enrichment plants?

A. The K-25 Site is maintained in a safe, shutdown mode pending results from the study regarding the costs, technologies, and priorities associated with the disposition of the plants. The Portsmouth Gaseous Diffusion Plant continues to work, producing commercial reactor fuel.

Q. How safe is the uranium storage at Portsmouth? Does it represent a hazard to the workers?

A. Onsite reviews indicate that the uranium storage is safe. The Portsmouth and Paducah Gaseous Diffusion Plants started operations in the early 1950's, and have been operated continuously since then. Uranium storage at the plants is primarily in the form of depleted, nonfissile "tails." These tails are stored in 10-ton and 14-ton cylinders in the form of uranium hexafluoride (UF6). Portsmouth currently has approximately 15,000 cylinders in storage, and Paducah has approximately 30,000 cylinders in storage.

The primary hazard associated with UF6 is toxicity, not radioactivity. When exposed to water and air, UF6 quickly converts to uranyl oxyfluoride (a white powder) and releases hydrogen fluoride. There have been inadvertent, small, localized releases of UF6. However, workers are routinely trained on procedures for responding to these releases.

To ensure the integrity of the stored cylinders, they are regularly inspected for deterioration. Cylinders that are determined to be substandard are removed from the storage area and refurbished or replaced. Studies are underway to determine the best way to convert the UF6 tails into an oxide that could be stored for long periods without the risk of chemical toxicity.

In addition to the tails, Portsmouth has residual highly enriched uranium as a result of enriching operations. This material is kept under regular surveillance in high security areas. Highly enriched uranium production stopped in 1992. The Department of Energy is currently studying options for disposition of the remaining highly enriched uranium.


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