by Thom Zaremba, shareholder at Roetzel & Andress
When I started looking for a subject that would pull me away from recycling architectural glass, I found a new use for glass that I could hardly believe, let alone ignore, namely, converting nuclear waste into glass!
But, before turning to that, I want to add a quick post-script to my last blog. After it went to press, the Wall Street Journal reported that California is finally doing something about plastic pollution. The state’s attorney general filed unfair competition and false environmental and advertising claims against several companies selling plastic bags. He did so after concluding that, while two recycling centers in the state claimed to accept plastic bags, none were able to confirm actually recycling them.
It is frustrating to learn that properly disposing of plastic bags may be part of a fantasy created to make us feel good about continuing to throw away single-use plastics! But let’s move on to something with a happy ending—turning radioactive waste into glass! It’s called vitrification. Wow—what does that mean?
Vitrification is a thermal process that involves melting glass-forming materials at high temperatures, then cooling them to form a stable, chemically inert glass matrix. It can be used to provide an environmentally stable medium to freeze biological samples, like embryos for cryopreservation, or to immobilize hazardous waste into solid, durable glass.
In the case of radioactive material, liquid waste is mixed with glass-forming materials, such as silica and alumina, and heated to high temperatures. Then, it is poured into containers and left to cool until it solidifies into glass. Once vitrified, the glass is so environmentally stable that, over hundreds of thousands of years, the trapped radioactivity willfully dissipates without ever leaching out of the glass into the surrounding environment.
Is this process of stabilizing nuclear waste through vitrification important? Yes, because nuclear facilities, such as the United States government’s site at Hanford, Washington, began manufacturing plutonium in the 1940s, and we’ve been trying to safely contain the massive amounts of nuclear waste left behind ever since.
Built as a part of the now infamous “Manhattan Project,” Hanford is not only the site of the world’s first nuclear reactor, but it’s also where the plutonium used in the world’s first nuclear bomb was manufactured. After that, Hanford’s nine nuclear reactors worked full-time for years, helping make enough plutonium to build the U.S. nuclear arsenal.
By the time it closed in 1987, Hanford had left billions of tons of contaminated liquids behind, stored in 150 or so underground tanks. Unfortunately, about a third of them leak, allowing radioactive waste to leach, first, into an underground aquifer and then into the Columbia River about seven miles away.
In October of this year, 16 years later than originally scheduled, the world’s largest radioactive waste treatment facility finally began “glassifying” radioactive waste from Hanford’s underground tanks. Glassification begins by combining radioactive waste with glass flakes heated to 2,100 degrees Fahrenheit in two 300-ton melters. The resulting molten glass is then poured into huge stainless steel storage cylinders—each capable of holding 6.6 tons—until it cools and hardens into glass.
The plant initially processed a 25,000-gallon batch of waste, and it’s expected to take about a year for the plant to reach full operation. It is expected to glassify about 40-50% of the low-level waste from Hanford’s tank farm. A second plant is on the drawing board to help process the rest. Eventually, a third plant is planned to glassify some five to six million gallons of high-level radioactive liquid waste held in those tanks.
The process is costly. In 2002, this clean-up was estimated to cost about $4 billion; however, the first plant actually cost $9 billion. Now, the total estimated cost of all three plants has ballooned to $30 billion.
The process also takes time. The Department of Energy (DOE) has targeted 2052 for the glassification of all of Hanford’s tank waste, but a recent document from the Government Accountability Office suggests that DOE may push that date back to 2069.
Its nearly perfect environmental stability is the reason glass was chosen as the medium to store the massive amounts of liquid radioactive waste we generated to assure that our nuclear arsenal is so large that a nuclear attack on America would result in the “mutual assured destruction” of … well … the entire planet.
Good, bad or indifferent, glass is now not only an essential building material, but it has become an essential part of our nuclear future!
Thom: Good articlee. The amount of plastic we throw away, recycling it should take precedence over cans, paper, and dare I say glass? A couple of years ago, I took on the role of Chief Bottle Washer, Cook, and Maid while my wife was recovering from a fall. It was really depressing to see how much plastic is used in food packaging. When you pick out fresh produce, you’re likely putting them in an even thinner, but still plastic bag. Pre-packaged lunch meat and cheese in the deli section comes in plastic, resealable bags. The meat is all wrapped in Styrofoam trays with a thin ceran-type film. Milk and soda bottles. The frozen veggies? The wrap around the frozen pizza? You’d go hungry if you tried just to buy food products that only come in metal cans or paper only. Here’s a challenge for you: Make those nuclear waste containers out of plastic – there’s got to be so much of it that the radioactive isotopes can’t possibly get thru. Although I do like the thought that glass can do that, too!
Chuck – I KNEW there were a lot of reasons – setting aside your extraordinary knowledge of … well, everything glass, glazing and especially curtain wall construction – that I liked you! Thanks for the kind comments! But, I’ll never fill your shoes Chuck!