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U.S. Department of Energy

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Declassification of the Amount of Weapon-Grade Plutonium Involved in Fires at the Rocky Flats Plant, near Denver, Colorado, in 1957 and 1969

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


Declassification of the Amount of Weapon-Grade Plutonium Involved in Fires at the Rocky Flats Plant, near Denver, Colorado, in 1957 and 1969

Table of Contents

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

The Department of Energy has declassified the amount of weapon-grade plutonium involved in fires at the Rocky Flats Plant near Denver, Colorado, in 1957 and 1969.

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. What is the health impact of plutonium released offsite and how much was released from the plutonium fires at the Rocky Flats Plant.

A. Two major fires occurred in 1957 and 1969 at the Rocky Flats Plant. A toxicologic review and dose reconstruction project, conducted by the Colorado State Health Department, have quantified the major chemical and radioactive materials released to the environment from Rocky Flats during its years of operation. Although data and information on the accidental releases are very limited, phase I of this study estimated that between 0.002 and 2.4 curies of fine plutonium particles were released from the 1957 fire and between 0.0001 and 0.056 curies were released from the 1969 fire. The estimate of plutonium released from the 903 Pad, where drums containing solvents contaminated with plutonium, was 25 curies. As all of these materials did not travel offsite or find their way into human exposure pathways, the highest predicted radiation doses to offsite residents were small. For example, the highest offsite dose resulting from the 1957 fire was estimated to be 50 mrem and the highest dose from the 903 Pad releases to be 100 mrem.

Phase I also estimated that a person offsite could have accumulated from 10-35 milligrams of carbon tetrachloride from 903 Pad, which is also a potential carcinogenic hazard. The second phase of the study will reevaluate historical records and monitoring data to help fill informational gaps and reduce uncertainties in the phase I study. It is currently underway and will be completed in 1996. Reference: "Project Task 5 Report Estimating Historical Emissions from Rocky Flats," March 1994, Prepared by ChemRisk, Alameda, California.

Q. Can you explain how Rocky Flats could have recovered more plutonium from the 1969 fire than was on the inventory books?

A. The "book inventory" does not contain the quantity in holdup since there was no way to measure any holdups at that time. After the 1969 fire, there was a large-scale cleanup of the area which resulted in an increase in the plutonium inventory. For example, plutonium powder was recovered from the gloveboxes which increased the inventory during the decontamination of the equipment. Holdup in the buildings was recovered and a net gain in plutonium resulted. Incidentally, we expect to recover additional holdup when the plant is fully decommissioned.


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