89 sieverts per hour measured in soil near Columbia River in Washington — Worst contamination just feet from groundwater…(4 Sieverts is fatal.)
February 6th, 2012
Title: Plan developed to clean up highly radioactive Hanford spill
Source: Tri-City Herald
Author: By Annette Cary
Date: Feb 6, 2012
Hanford officials have settled on a plan to clean up what may be the most highly radioactive spill at the nuclear reservation.
It depends on calling back into service the 47-year-old, oversized hot cell where the spill occurred to protect workers from the radioactive cesium and strontium that leaked through the hot cell to the soil below.
Radioactivity in the contaminated soil, which is about 1,000 feet from the Columbia River, has been measured at 8,900 rad per hour [89 sieverts per hour]. Direct exposure for a few minutes would be fatal, according to Washington Closure. […]
In the 1980s, cesium and strontium spilled inside the hot cell, according to a 1993 report that referenced the spill. Germany needed a heat source to use for tests of a repository for radioactive waste, which emits heat, and the cesium and strontium were being fabricated into the sources.
“This was concentrated material,” said Mark French, the Department of Energy’s project director for Hanford cleanup along the Columbia River. […]