89 sieverts per hour measured in soil near Columbia River in Washington, Worst contamination just

[stockholmer]

feet from groundwater.

http://www.tri-cityherald.com/2012/02/06/1815387/plan-developed-to-clean-up-highly.html

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 http://www.unitconversion.org/radiation/rads-per-second-to-sieverts-per-second-conversion.html ) . 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. [...]

It migrated down in a open square shape, with the worst contamination down to five or six feet deep, McBride said. There is not evidence that it has reached the ground water which is about 54 feet below the ground there and about 42 feet below the bottom of the hot cell [...]


snip

[NNN0LHI]

1. A link for those like me who didn't know what a "hot cell", is

http://en.wikipedia.org/wiki/Hot_cell

[TheWraith]

2. 8900 rad per hour? Bullshit.

There is no way that a 47 year old leak could be that hot. Somebody needs to go back to journalism school.

[Demonaut]

3. a full 89 sieverts???? mebbe millisieverts, misquote

[johnd83]

5. I agree that sounds really high

From an article on nuclear radiation exposure:

The March 2011 accident at Fukushima Daiichi nuclear power plant in Japan released more radioactivity than Three Mile Island, but much less than Chernobyl, probably about 770 PBq, and the effects are still being assessed. Certainly the main radiation exposure was to workers on site. In the first month 22 workers had received doses over 100 mSv, and none had reached 250 mSv - the limit set for emergency workers there. There were around 250 workers on site each day. INES rating 7.

So the workers in the completely destroyed nuclear reactor were exposed to 250 mSv over the course of a few days. 89 S/hr is an insane number. Based on an (unconfirmed) estimate that is about half the exposure of being 100 m from an atomic bomb explosion.

http://www.world-nuclear.org/info/inf05.html

[gratuitous]

4. It's an even bet in Portland

Will we get snuffed by an earthquake first, or will the radiation migrating from Hanford depopulate the Rose City? At least we had jobs!