Consequences of Explosion of Hanford's Single-Shell Tanks Are Understated
RCED-91-34: Published: Oct 10, 1990. Publicly Released: Oct 10, 1990.
- Full Report:
Pursuant to a congressional request, GAO evaluated the potential for ferrocyanide explosions in underground tanks containing high-level waste at the Department of Energy's (DOE) Hanford site.
GAO found that: (1) DOE lacked sufficient information for judging the probability of a ferrocyanide explosion, and not enough was known to rule out the possibility of a spontaneous explosion; (2) the Hanford environmental impact statement understated the potential consequences of a ferrocyanide explosion; (3) a ferrocyanide explosion could contaminate large areas within and possibly beyond site boundaries and result in high-level radiation exposure at levels with significant radiation-induced cancer consequences; (4) a DOE task force agreed with a GAO assessment that the respirable fraction of radioactive particles produced by an explosion would be higher than originally thought and recommended additional studies; and (5) in response to Defense Nuclear Facilities Safety Board recommendations, DOE planned to study possible chemical reactions that could cause heat generation in the storage tanks, improve temperature measurements, and test radiation stability of ferrocyanide precipitates and the energetics of ferrocyanide reactions.
Recommendation for Executive Action
Status: Closed - Implemented
Comments: DOE/Westinghouse Hanford have completed the studies recommended by the Ad Hoc Task Force. Analyses have shown that ferrocyanide reactions are difficult to initiate, are prevented by the presence of a small amount of water, and will not propagate unless sufficient fuel is present. Experiments have also established that ferrocyanide waste ages to form less energetic products under waste tank conditions. According to the analyses, the necessary conditions for a ferrocyanide explosion do not exist and, therefore, a ferrocyanide explosion is considered improbable.
Recommendation: The Secretary of Energy should direct the DOE Richland Operations Office to implement the recommendations made by the DOE Ad Hoc Task Force on September 20, 1990.
Agency Affected: Department of Energy