Tuesday, October 23, 2012

Cleaning Up the Mess at Hanford


Hanford From Space
Google Earth

The last several weeks we’ve been talking and reading about nuclear waste storage in preparation for a forum Gallatin hosted in late September that included several different points of view on the Hanford cleanup, in my mind the country’s most important environmental project.

Gallatin has a special resource on nuclear waste, John Kotek, the new head of our Boise office.  For the previous two years, John was staff director for the President’s Blue Ribbon Commission on America’s Nuclear Future where he worked with some top people who are struggling with the complexities of finding a place to store the high-level detritus of the country’s nuclear programs, nearly 70 years after they began.  John, a nuclear engineer, also brings the experience of administering the Federal Department of Energy contract for the programs of the Idaho National Laboratory.

The panel at the forum included our man Kotek as well as Jane Hedges, the Washington State Department of Ecology manager who runs the state’s nuclear waste program and represents the state’s interest at the Hanford cleanup site.  Our third expert was Ward Sproat, who came out of the civilian nuclear power industry in Pennsylvania and was appointed by President George W. Bush to oversee the license application for the proposed nuclear waste repository at Yucca Mountain.  Sproat is widely known within the industry to have turned that project around, though Yucca Mountain has since been taken off the table by President Obama at the urging of Harry Reid, Senator from Nevada and a staunch opponent.  Sproat has joined the Bechtel National team working on the Waste Treatment Plant at Hanford, which will stabilize nuclear waste and other contaminants there by fusing the waste into glass logs.

Single-wall tanks under construction, 1944
Department of Energy
We asked each panelist to give a status report from their unique point of view.  Hedges reported that the state sees considerable progress in Hanford cleanup.  She cited as a key risk-reducing accomplishment the fact that most of the liquids residing in the old single-wall waste storage tanks, have had their liquids pumped into newer, double-wall tanks.  What remains in the old tanks is a semi-solid, dry cake-like substance that contains a great deal of radioactivity but is far less likely to leak.  She pointed out, however, that the double-wall tanks are also getting older and recently a leak was detected in one of them – into the space between the two walls.

Cocooned C Reactor
Department of Energy
Hedges also said that the process of cocooning the plutonium producing reactors was continuing with six of the nine nuclear reactors sealed in cement and steel that will isolate the hot reactor core for up to 75 years.  Once sealed, the facilities are monitored remotely for heat and moisture. Every five years, workers enter the structure to evaluate its condition and to ensure there are no avenues for intrusion by animals or the elements. 

Making plutonium at Hanford was a messy process that required nuclear reactors to irradiate uranium fuel assemblies.  Some of the uranium in the fuel assemblies was converted to plutonium. The plutonium was separated from the uranium using a caustic chemical slurry that created a great deal of waste in the process.  The result is weapons-grade plutonium that is 93-94% pure and, when suddenly compressed inside a weapon, initiates a chain reaction explosion of considerable force. The bomb at Trinity, New Mexico was made with Hanford plutonium as was the bomb dropped on Nagasaki.

During World War II and the Cold War that followed, many different reactors were constructed and several different extraction processes used.  The result creates huge technical challenges to clean-up because the character of the waste varied from process to process. 

Hedges said that the vitrification process that has been chosen for Hanford is the right technology, but because of the complexity of the waste, still faces technical challenges to the mission of incorporating waste into glass logs for permanent storage.  

Sproat said that the plant is now more than 60% complete.  The glass log technology has been successfully used in the US and in France, but the combination of the wastes and chemicals at Hanford, the different sizes of individual parts of the waste and other evolving information about the character of the waste make it difficult to complete design and finish construction of the vitrification plant.  Sproat’s company is involved in successfully decommissioning tanks and vitrifying the waste at the Savannah River complex in South Carolina, although the waste there is less complicated than the Hanford waste.

A third component of the discussion was what to do with the waste after it is processed.  For now, and for the foreseeable future, Kotek said high-level waste and commercial nuclear fuel rods will have to stay in place.  He said the Blue Ribbon Commission had come to the conclusion that a top down, federally mandated site solution would be riskier and more expensive and Kotek said that the commission was recommending a consent-based approach.  He said that recent successful public processes in Finland, Sweden and Spain led the commission to believe that there may be a better way to talk to communities about hosting nuclear waste storage.

Kotek said the Commission also recommended a change of governance for nuclear waste storage, from the federal Department of Energy to a new, single-purpose government corporation with responsibilities to “site, license, build, and operate facilities for the safe consolidated storage and final disposal of spent fuel and high-level nuclear waste at a reasonable cost and within a reasonable time frame.”

Legislation to accomplish this task has been introduced in the current session of the Congress and will spark a long-needed conversation about United States’ goals for its nuclear waste programs.
We tend to think of Hanford as focused on turning highly radioactive waste into glass logs, but the cleanup is an enormous undertaking with many components and a cost of two billion dollars/year.
Hanford B Reactor, the First Plutonium Reactor
Department of Energy

Good and convenient sources allow the lay person to get a grasp on the history of waste at Hanford. In 2003, the Pacific Northwest National Laboratory wrote a short history of waste at Hanford and set out just what kind of materials were put into the 1600 disposal sites that served nine nuclear power plants and five plutonium processing facilities. Used in tandem with the Department of Energy’s Hanford website, it is possible to update and enrich this remarkable history.


“From 1944 through the late 1980s, Hanford generated nearly 525 million gallons of high-level tank waste.  Liquid evaporation, discharge to the ground, chemical treatment and tank leakage reduced this volume by 90%— to 54 million gallons.  This is about 60% of the tank waste existing across all U.S. Department of Energy nuclear activities. Today, this waste contains about 195 million curies of radioactivity and 220,000 metric tons of chemicals,” the PNNL report says.

Hanford Tank Complex, About 1953
The report says that much of this waste, generated between 1944 and the late 1980s, is stored in 177 tanks on site of which 149 are single-shell tanks built between 1943 and 1964 with a useful life expectancy of 20 years.  Sixty-seven of these tanks have leaked or are suspected to have leaked one million gallons of liquid into the underlying sediment, beginning in 1956.  Here’s how the Department of Energy’s Hanford website describes how this waste got out and into the ground.  

“Even with 149 tanks, the volume of chemical wastes generated through the plutonium production mission far exceeded the capacity of the tanks. Some of the liquid waste did end up being put into holding facilities and some was poured into open trenches. Some of the wastes that were put into the tanks didn’t stay there, as the heat generated by the waste and the composition of the waste caused an estimated 67 of these tanks to leak some of their contents into the ground. Some of this liquid waste migrated through the ground and has reached the groundwater.”

With the shutdown of the N Reactor in 1987, no more plutonium has been made there.  Over the years the double-wall tanks have received liquids originally put into the single-wall tanks, providing better protection.   PNNL’s 2003 history reported that no double-wall tank had leaked, though some of those were reaching their design life.  As Jane Hedges reported during the panel discussion, a double-shell tank was recently found to have leaked into the space between the inner shell and the outer shell. 

Spent nuclear fuel was stored on site as well, about 2,100 tons.  The fuel was irradiated in the N Reactor, the dual-purpose reactor that produced plutonium for weapons and steam for electricity.  The fuel was then moved to two aging, water-filled concrete basins and never reprocessed, sitting in the water for years.  The report says that some of this fuel corroded and radionuclides migrated to the local soil and ground water. However, after 2003, that basin water was treated and disposed (Hanford cleanup treats 28,000,000 gallons of water each year) and the fuel assemblies have been taken out and stored in carbon steel tubes.  They reside today in what is called the “Canister Storage Building,” where it and Waste Treatment Plant steel canisters holding vitrified waste will be stored until a national repository is built.

There has also been some progress made in stabilizing the old single-wall tanks.  By the middle of last month, three single-wall waste tanks had been emptied this year, bringing the number of emptied tanks to ten.  Some contain small amounts of material that has hardened on the floors of the tanks and will require additional work before full decommissioning.

Low Level Nuclear Waste Disposal, Hanford 1950
Department of Energy
Best practices in the 1940s and 1950s were not as stringent as today’s.  Many wastes containing radioactive material were landfilled on site in those days.  A nine-acre burial site called 618-11 is one of those sites and clean-up us slated for about two years from now.  However, before moving dirt, a great deal of research must be done to learn what may have been disposed into the burial ground.  Complicating that research is that some of the records do not exist or appear contradictory.  In 1999, the PNNL history says the 9-acre 618-11 burial ground, located not far from the Energy Northwest commercial reactor complex, revealed groundwater samples with elevated levels of tritium—as much as 400 times above drinking water standards.

Handling radioactive materials creates radioactive garbage. Refrigerators, ovens, old clothing, shoes, pumps, equipment, vehicles, railroad cars – all the tools of long-ago experimentation and testing must be buried or put into containers for storage and future disposal. 

Plumes of radioactive and hazardous material are moving toward the Columbia River from land disposal and leaks.  Depending on the contaminants, some move slowly and others move with considerable speed.  The cleanup effort must monitor these plumes and manage their movement.

The PNNL history says that 110 million curies of radioactivity were discharged into the Columbia, a significant number, though a large percentage of the discharge was in elements with short half-lives.  Magnesium, for example, with a half-life of just over two and a half hours, accounts for two-thirds of the curies discharged into the river.   The history says that the largest releases into the Columbia occurred in 1963 when eight reactors were working and plutonium production was at its zenith.  In those days, a typical resident, according to PNNL, would receive one to five millirem/year over normal background radiation, a relatively small amount.  However, a frequent user of the Columbia who worked on the river and has a significant amount of fish in his diet would have experienced a 50-130 millirem dose, 15%-45% above background levels.  The PNNL study says that Native Americans exposed to those 1963 levels and who also consumed a lot of river fish would have been exposed to fifty times more radiation than exists in the natural background.  Today, none of the reactors built for plutonium production are working and two-thirds are cocooned and none of the plutonium reprocessing plants are operating.  Called canyons, because of their length and high walls, these plants remain shut down but still are highly radioactive.

A Hanford cleanup agreement between the Department of Energy, the Environmental Protection Agency and the State of Washington Department of Ecology was agreed to in 1989 with the leadership of then Attorney General Chris Gregoire and was updated in 2009 with a court-supervised consent decree.  The agreement covers many different disposal sites across the reservation.  Most of these materials will have to remain on site until a national nuclear waste repository is found, studied, approved, permitted and built. 

The clean-up at Hanford is a legacy issue, depending on stable funding over many years – the current schedule calls for continued intense efforts along many fronts.  Not all of these fronts have a secure end-date.  Also, future funding for Hanford cleanup and for a new, national repository to store what is removed at Hanford depends on the congressional appropriations process, even though commercial nuclear plants set aside today some $750 million a year for a national repository.  This money is considered revenue by the federal government and is not, as originally contemplated, a fund of its own.  Getting the money requires the appropriations process.  Making funding even more difficult is the fact that the federal government is completing some of its cleanups in other parts of the country.  Twenty-nine states were part of America’s nuclear program and needed various levels of cleanup.  Today, however, 15 of those have moved from cleanup to monitoring, making the issue less urgent to Congressional delegations in those states where the cleanup is finished. 

Seventy years ago, in December 1942, a group of scientists toured the Hanford Site, one of a handful of sites under consideration for the world’s first plutonium factory.  They knew that the science of nuclear energy was widely shared among scientists and academics around the world before World War II and that the Nazis both knew about the atom’s potential as a weapon and had demonstrated great innovation and success making new weapons.  They knew that in December 1942, the Germans appeared to be in command at Stalingrad, owned nearly all of Europe and the Mediterranean Sea and were raining bombs on London.   The scientists were in a hurry to produce an American atomic weapon and left us a shorter war and highly contaminated place in the center of our state next to our great river.

Under the best of circumstances, cleanup will be ongoing well into the middle of this century with the areas under active cleanup becoming smaller and concentrated toward the center of the site, away from the river.  In a way, it is a kind of cathedral.  People working on it today will never see it finished, though it is one of the most significant public works our country will ever do.  It creates amazing and difficult management problems that require a focus on tomorrow’s end game while solving today’s immediate and difficult problems. 

Department of Ecology Waste Program Website 

Short History of Hanford Project

Department of Energy Hanford Cleanup Website

Vitrification Plant Summary

2 comments:

  1. we are ALL in BIG trouble, bottle is open and lid wont go back on god help us all

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