nuclear-news

A very long haul to clean up Savannah River’s plutonium wastes

The amount of plutonium in the waste tanks is uncertain. Savannah River was built to make plutonium, and the material in the tanks is what was left over after the material was produced in reactors and scavenged in chemical plants. But a fair amount ended up in the waste tanks

A Very Long Road for Military Nuclear Waste By MATTHEW L. WALD, NYT, March 29, 2012  Slowly, slowly, the Energy Department is moving forward with solidifying the liquid nuclear wastes left over from cold-war weapons production. On Thursday, the department said it had closed two more of the 51 underground tanks at the Savannah River Site  in western South Carolina. The high-level waste was mixed with molten glass to keep it chemically locked up for millennia, and the lower-level material was mixed with a kind of cement that is supposed to keep it in place until the radioactivity dies down.

The department has 22 tanks at Savannah River that do not meet Environmental Protection Agency standards , mostly because they are single-wall tanks rather than double-wall. It closed two of them in 1997 but has faced numerous technical problems. Now it says it will have four more done by 2014 or 2015, and all of them by 2028. It is
starting with the tanks that are closest to the water table because their contents would spread most rapidly if they leaked. (The area has a high water table.)

Yet the “closed” tanks are not actually empty. “More than 99 percent
of the waste originally stored in these two tanks has been removed,’’
said Thomas P. D’Agostino , undersecretary of energy. Since the tanks
held more than a million gallons each, that could leave tens of
thousands of gallons in place.
One problem is that the tanks have cooling coils and other hardware in
place that makes cleaning difficult. But the department says it has
developed new methods, including robotic tools, to get the tanks
cleaner. Another problem is that the process of emptying the waste
includes spraying new materials inside to get the liquids flowing.

An environmental group, the Natural Resources Defense Council , sued
the department after the last round of tank closures, arguing that the
radioactive material left behind could eventually enter soil and
groundwater, and that the department was granting itself too much
discretion in deciding how clean was clean enough. Congress eventually
stepped in to clarify that in South Carolina and Idaho, some waste
could be left behind.

At similar tanks in New York  and Washington State , the question was
left open…………. The tanks and the waste aren’t going anywhere.
The grouted material is in giant blocks, called monoliths, nearby, and
the material put into glass is destined to go to whatever federal
repository is eventually established, following the cancellation of
the Yucca Mountain waste repository in Nevada.

The amount of plutonium in the waste tanks is uncertain. Savannah River was built to make plutonium, and the material in the tanks is what was left over after the material was produced in reactors and scavenged in chemical plants. But a fair amount ended up in the waste tanks , according to Robert Alvarez, an outside expert who formerly worked for the Department of Energy.
http://green.blogs.nytimes.com/2012/03/29/a-very-long-road-for-military-nuclear-waste/

March 30, 2012 - Posted by Christina Macpherson | - plutonium, Reference, USA