This series of articles, "On The Yellowcake Trail," tracks the history of all aspects of uranium in Canada from the mining and milling, to processing and use, throughout its eighty-year history. The series began with the history of uranium mining in Canada. This article examines the various stages involved in processing uranium and the issues that emerge with each of these stages.
For the complete series in PDF format click HERE
On the Yellowcake Trail Part 2
The nuclear industry paints a rosy picture of its operations, portraying itself as a well-planned, controlled and safe industry, and the answer to climate change. But the track record of flooding and spills at mine sites, cost overruns, delays, leaks and shutdowns at nuclear plants, and the catastrophic nuclear "accidents" at Chernobyl and Three-Mile Island, are in stark contrast with that positive image. At every stage in the nuclear chain, from extraction to processing and use, vast amounts of radioactive waste and other highly hazardous wastes are produced. Spills and leaks commonly occur, marking treacherous places in the yellowcake trail that remain deadly for hundreds of thousands of years.
Nuclear waste is the Achilles' heel of the industry. The radioactive wastes resulting from mining and milling uranium are endemic, as is the nuclear waste (spent fuel) produced by reactors, which contains so many extremely dangerous radioisotopes, such as plutonium. There is no safe way to permanently store radioactive nuclear waste.
The current recession has put a damper on the nuclear renaissance, at least in Ontario. Plans to build a nuclear reactor at Darlington have been postponed indefinitely and proposals by Bruce Power, a private company, to build two new nuclear power stations have been abandoned. Of course the future of the somewhat tarred Atomic Energy of Canada Limited is also in doubt, as the federal government is hell-bent on privatizing it.But mining and exploration for uranium are going on full steam ahead, and Bruce Power is marching westward, seeking opportunities in areas with better economies than a "have-not" Ontario.
Canada's Uranium - A Travelogue
Canada's uranium, as yellowcake and in other more purified forms, travels the globe. How it gets to these various destinations is another matter. From the mines and mills in Saskatchewan, casks of yellowcake are shipped about 3000 kilometres to Ontario. Some of the yellowcake may be shipped directly to the US and possibly to France.Approximately 85% of Canada's uranium yield is exported.
Since nearly all the uranium produced in Canada is sold under confidential long-term contracts, information on amounts shipped and to what countries is not forthcoming - at least not to the public.The ore from the uranium mines is shipped by truck to the mills. Trucks bring the yellowcake from the mills to Saskatoon. The yellowcake travels most likely by truck from Saskatoon to the refinery in Blind River, Ontario. The Blind River refinery also gets shipments of yellowcake for processing from around the world. Most of the purified uranium is trucked from Blind River to Port Hope, 600 kilometres away. The rest is sent to the UK for enrichment. This is as much as we know. Any road or rail travel must go through a number of towns en route. What emergency measures are in place in case of accidents or major spills? How is such transportation insured? To what degree are any incidents or accidents reported publicly?In one case, two transportation trucks carrying uranium hexafluoride from Cameco's Port Hope facility were photographed in the public parking lot of a gambling casino near Milton, Ontario. Likely the trucks were on the way to the US enrichment plant in Kentucky.
On Aug. 4, 2009, the Canadian Press reported an incident where two truckers were exposed to radiation while hauling a radioactive device for six days across the country. Apparently, the device had not been securely locked in place before transit, causing it to shift from a shielded to an unshielded position en route. A preliminary investigation by the Canadian Nuclear Safety Commission (CNSC) found that the drivers received about 35% more radiation in their six-day trip than the regulated public dose limit for one full year. How many more such incidents go unreported?
Churning Out the Yellowcake and the Waste
Mining and milling are at the forefront of the nuclear chain. As in any mining operation, they go hand-in-hand. Mining extracts the raw uranium ore from rock and milling processes the ore to produce yellowcake.
At the mill, usually located at or near mine sites, the ore is crushed, then treated with strong acids and other chemicals to selectively leach out the uranium from the ore and dry it to a fine sand-like powder, uranium oxide concentrate U3O8 - yellowcake (about 70% pure uranium).
Finally, the yellowcake is packed into 55 US gallon steel drums, similar in size to oil barrels, each containing about 400 kilograms of yellowcake, ready to begin its long journey to be further refined.
Yellowcake is one product of the mills, the other is waste. Throughout all stages of processing, copious amounts of water are used, and numerous toxic chemicals used in processing are unleashed. Usually the liquid waste is about double the quantity of the solid waste.
The leaching agent, typically sulphuric acid, extracts uranium from the ore and along with it, several other substances, including heavy metals, such as molybdenum, lead, arsenic, mercury, manganese and cadmium.
Since a relatively small fraction of uranium is actually contained in the ore, the rest of the ore is radioactive waste. The vast amounts of wastes, known as tailings, are discharged from the mills into ponds or piles nearby. The tailings contain all the original constituents of the ore, including long-living radionucleides, thorium-230 (half-life of 80,000 years) and radium-226 (half-life of 1600 years), which represent about 85% of the initial radioactivity of the ore. The tailings also contain about 5-10% of the uranium not extracted by the milling process.
The radium in waste rock and tailings continuously decays to the radioactive gas radon-222, which can readily escape from the interior of the tailings. Radon releases are a major hazard that continues after uranium mines and mills are shut down. Just to prevent seepage of radon gas from the interior of the tailings, the waste must be stabilized by at least two metres of cover soil.
The mix of constituents in the tailings can undergo various reactions which contribute to additional hazards. The poisoning of fish and plants downstream from the mines and mills is due not only to radioactive substances that accumulate in the sediment but also to heavy metals and process chemicals, whose effects are noticed long before the effects of radioactivity.
From the Mills to Ontario....and Beyond
Because yellowcake is about 70% uranium, further processing is required to remove impurities before it can be used. From the mills in Saskatchewan, casks of yellowcake travel to Ontario, the only province in Canada where yellowcake is refined for further use. Each load hauled by truck contains about 17 tonnes of yellowcake.
Some of the yellowcake may also be shipped directly to the US and other locations overseas, but neither the destinations nor the means of transport are publicly known.
Ontario hosts the largest uranium refinery in the world, the Blind River refinery on the north shores of Lake Huron,and the oldest existing one, in Port Hope, on Lake Ontario. Both are owned by the Cameco Corporation, a dominant and influential force in the two communities. The Blind River facility, first opened in 1983, processes yellowcake not only from Saskatchewan, and formerly Ontario's mines, but from all over the world. At the Blind River refinery, the yellowcake is purified and processed to produce uranium trioxide (UO3), a highpurity form of uranium suitable for further processing.
Incineration - the Path of Destruction
In 2007, the Canadian Nuclear Safety Commission (CNSC) gave Cameco approval to upgrade its existing incinerator at the Blind River refinery so that it could burn radioactively-contaminated by-products generated at Blind River and Port Hope.
Uranium, a metal, cannot be destroyed by incineration.
It is pyrophoric, that is, it can catch fire even at normal temperatures when it is in fine particles. Incinerated, it will burn at 3,000 to 6,000 degrees centigrade and the uranium particles turn into ceramic uranium.
"Ceramic uranium is not soluble in body fluids after being breathed into the lungs. This metal vapour will solidify in the cooling air and form respirable particles. Some particles will be nanometre in size (a nanometre is 1 billionth of a metre), so small that they can pass through the lungblood barrier, escape from the blood vessels and enter into the cells. They can also pass through the blood-brain barrier and enter into the brain itself. These particles have been found in seminal fluid and in the female where they can cross the placenta and cause havoc to the developing embryo or foetus. These metal fumes also pose an immediate danger for the residents of downwind communities."
-Burning Radioactive Waste: Blind River and the CNSC Decision, International Institute of Concern for Public Health, March 17, 2007
Recovery of Left-over Uranium
Cameco is currently seeking approval from CNSC to re-mill "recyclable" products from its Blind River and Port Hope facilities, trucked back to its Key Lake mill in Saskatchewan. These products contain approximately 4% uranium, mostly, but not all, derived from yellowcake from Saskatchewan.
Once again, yellowcake hits the road - back to where most of it came from.
Blind River to Port Hope
From Blind River, UO3 is trucked 600 km to Port Hope where it is converted into two forms. About 20% is powdered uranium dioxide (UO2), used to fuel Canadian Deuterium Uranium (CANDU) heavy water reactors in Canada and abroad. The other 80% is turned into uranium hexafluoride (UF6), known as "hex," which is used to enrich uranium for fuel in light water reactors. Since there are no enrichment plants in Canada, all of the "hex" produced is transported in steel shipping containers to enrichment plants in the US, Europe and Japan. Since 2006, about one-quarter of the Blind River UO3 (5,000 tonnes) is being shipped to Springfields, UK, where it is converted to UF6 which is then sent to enrichment facilities in Europe.
Cameco, through its Port Hope and UK operations, is the world's largest conversion supplier, accounting for 35% of the western world capacity. Its Port Hope Conversion Facility is the world's only commercial supplier of fuel-grade (unenriched) UO2.
The last stage in processing the original yellowcake is the transformation of powdered UO2 to reactor fuel. UO2 is first pressed into small cylindrical shapes and then baked at a high temperature (1600 °C) to produce hard ceramic pellets. The pellets are ground down and placed in zirconiumalloy tubes which are especially resistant to corrosion. Finally the tubes (also called fuel rods) are grouped into bundles.
Cameco's facility Cameco Fuel Manufacturing Inc., (formerly Zircatec Precision Industries Inc.) in Port Hope produces fuel pellets and bundles. General Electric-Hitachi operates a plant in Toronto which produces fuel pellets which are then sent to its Peterborough plant where fuel bundles are produced.
Now, the yellowcake trail takes a very different path, in the form of fuel bundles which are shipped to Canadian nuclear power generating plants and CANDU-type reactors around the world.
Anna Tilman has researched several toxic issues, especially mercury. She is a Board member of the International Institute of Concern for Public Health.
Miles Goldstick, Wollaston, People Resisting Genocide, Black Rose Books, 1987
Benjamin A. Goldman, Discounting Human Lives: Uranium and Global Equity, Avebury Studies in Green Research, 1994