- Title: Nuclear waste development helping Hanford clean-up
- Date: 28th December 2016
- Summary: PISCATAWAY, NEW JERSEY, UNITED STATES (RECENT) (DECEMBER 14, 2016) (REUTERS) LAB TECHNICIANS AT RUTGERS UNIVERSITY REMOVING GLASS FROM FURNACE VARIOUS OF OVEN TEMPERATURE GAUGE READING 1675 DEGREES CELSIUS EXTERIOR OF RUTGERS UNIVERSITY DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING ASSISTANT PROFESSOR ASHUTOSH GOEL ENTERING BUILDING (SOUNDBITE) (English) RUTGERS ASSISTANT PROFESSOR ASHUTOSH GOEL SAYING: "The problem in low activity waste is there are some species, radioactive elements, in this low activity waste which have got half-life of millions of years that they won't go away for the next millions of years. And some of them are, for example, technetium-99, iodine-129, which are water-soluble. They can go underground. They can dissolve in underground water, you know, they can enter your food chain. A lot of things can happen." VARIOUS OF CRUCIBLE CONTAINING GLASS REMOVED FROM FURNACE (SOUNDBITE) (English) RUTGERS ASSISTANT PROFESSOR ASHUTOSH GOEL SAYING: "So, we have been funded by U.S. Department of Energy to create a waste form, to come up with a waste form, for a ceramic which can be synthesized at low temperatures, because iodine doesn't like to enter into glass. We melt glasses at high temperatures - at 1100C, 1150C; 1150C is the temperature at which glass will be melted at Hanford site. So, iodine above 500C, it volatilizes. So, what to do with it? It doesn't like to enter into glass. Synthesize a waste form somewhere at room temperatures and that's what the project was assigned to us and we have been successful in doing that. We have come up with a methodology where we can synthesize a waste form of ceramic which can contain radioactive iodine in it and we can synthesize it completely at room temperature - just mixing some chemicals in water and you're done." WATER CONTAINING GLASS POWDERS SPINNING ON MAGNETIC TABLES DETAIL OF WATER CONTAINING SODIUM VANADATE (SOUNDBITE) (English) CHARLES CAO (pronounced CHOW), GRADUATE STUDENT AT RUTGERS LAB SAYING: "Well, iodine volatilizes at 500C. So, what we're doing over here is we're actually able to synthesize this material at room temperature, which is pretty significant and a pretty big difference." CAO MIXING IODINE SOLUTION AT LAB (SOUNDBITE) (English) CHARLES CAO (pronounced CHOW), GRADUATE STUDENT AT RUTGERS LAB SAYING: "We're synthesizing the non-radioactive powder and just proving that we can mix these chemicals in the right proportions and produce this powder so that when you take it to an industrial-scale level, you can use these same chemicals to turn it into the proper waste form that can immobilize iodine." VARIOUS OF IODINE SOLUTION BEING MIXED CAO POURING SLURRY INTO PETRI DISH VARIOUS OF DRIED CERAMIC IODINE POWDER IN PETRI DISH
- Embargoed: 12th January 2017 16:33
- Keywords: nuclear waste radioactive Hanford Site iodine-129 plutonium Trinity Device Fat Man Nagasaki nuclear arms Rutgers University
- Location: PISCATAWAY, NEW JERSEY, UNITED STATES / FILE LOCATIONS
- City: PISCATAWAY, NEW JERSEY, UNITED STATES / FILE LOCATIONS
- Country: USA
- Topics: Life Sciences,Science
- Reuters ID: LVA0015ESQ923
- Aspect Ratio: 16:9
- Story Text: After more than fifty years of producing nuclear material for the most powerful weapons in the United States' arsenal, the Hanford Site in Washington State is now the site of arguably the largest environmental clean-up project in the country's history.
Hanford was the site of the world's first full-scale plutonium production reactor for the Manhattan Project, in which the material used in the first atomic device tested at Trinity in New Mexico and the bomb detonated over Nagasaki was created.
At the height of the Cold War the facility at Hanford operated nine nuclear reactors and five plutonium processing plants. By the time of its decommissioning, completed in 1987, the plant had provided nearly all the plutonium for the more than 60,000 nuclear weapons of the U.S. military - and the waste to go with it.
Containment of the radioactive waste has been a troublesome issue for the site. The environmental price for being the world's first nuclear superpower has been huge, with the legacy of Hanford becoming the most contaminated nuclear site in the country with at least 56 million gallons of corrosive radioactive waste left stewing in 177 storage tanks, a number of which are known to be leaking.
A multi-billion dollar clean-up program under the aegis of the Department of Energy, now in its third decade, has determined how to dispose of the material by converting the sludge waste into a stable glass suitable for storage deep in the ground - for millions of years.
The idea is to mix and heat the material - rich in sodium and alumina (refined bauxite, which is a raw material for making aluminium) - with silica and boric acid in a vitrification plant to produce the glass.
However, not all of the waste can be readily converted.
"The problem in low activity waste is there are some species, radioactive elements, in this low activity waste which have got half-life of millions of years, that they won't go away for the next millions of years," explained Ashutosh Goel, assistant professor at the Department of Materials Science and Engineering at Rutgers University in New Jersey. "Some of them are, for example, technetium-99, iodine-129, which are water-soluble. They can go underground. They can dissolve in underground water, you know, they can enter your food chain. A lot of things can happen."
A veteran of the DoE's Pacific Northwest National Laboratory next to the Hanford Site, Goel now runs a lab focused on glass science and vitrification.
Tackling the problem of iodine-129, whose half life is more than 15 million years, is a crucial factor in processing the waste at Hanford. The radioactive isotope can spread easily and is known to target the thyroid gland and increase the possibility of cancer in those exposed. The Fukushima-Daiichi nuclear accident in Japan in 2011 saw, for example, worrying levels of iodine-129 dispersed.
"We melt glasses at high temperatures - at 1100-1150C; 1150C is the temperature at which glass will be melted at Hanford Site. So, iodine above 500C, it volatilizes. So, what to do with it? It doesn't like to enter into glass," said Goel.
His team at Rutgers has found the means to synthesize iodine into a ceramic powder.
"That's what the project was assigned to us and we have been successful in doing that. We have come up with a methodology where we can synthesize a waste form of ceramic which can contain radioactive iodine in it," Goel finished.
While the process of transforming iodine into a solid has been known for some time, the standard method requires high heat and pressure in sealed vacuumed conditions - a method unsuitable for the scale required at Hanford.
The development at Rutgers has been the discovery of a means of transforming iodine at room temperature and thus preventing, in theory, the contaminant from dispersing.
"What we're doing over here is we're actually able to synthesize this material at room temperature, which is pretty significant and a pretty big difference," said Charles Cao, a graduate student at the Rutgers lab who was instrumental in the breakthrough.
"We're synthesizing the non-radioactive powder and just proving that we can mix these chemicals in the right proportions and produce this powder so that when you take it to an industrial-scale level, you can use these same chemicals to turn it into the proper waste form that can immobilize iodine," Cao added.
The process itself is relatively simple. Water containing lead nitrate, sodium vanadate and sodium iodide are combined and strained through a filter to create an iodine slurry that is then dried into a powder.
The next step for the Rutgers team, which they hope to finalize within a year, is figuring out the best composition of glass with which to combine the ceramic iodine powder created by their process. The resulting procedure will then be submitted to the Department of Energy for consideration at the vitrification plant being built at Hanford and scheduled to go online in 2022.
The transformation of the nuclear waste into glass will take the Department of Energy several more decades to complete, with the resulting stable radioactive material initially being stored at Hanford before being moved to a yet-to-be-named geological repository. - Copyright Holder: REUTERS
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