Posts Tagged ‘nuclear waste’
Tuesday, May 7, 2013 @ 11:05 AM gHale
Millstone nuclear plant in Connecticut requested to significantly expand nuclear waste storage capacity and the Connecticut Siting Council has approved the plan.
The council voted unanimously without discussion Thursday to allow Millstone to build concrete pads necessary for an expansion of its waste storage at the Waterford site.
The plant could add as many as 135 dry casks storage units by 2045. There are 19 now.
Millstone Power Station’s owner Dominion Resources Inc. asked for permission to expand storage because federal officials have not found a central site for nuclear waste. Spokesman Ken Holt said increasing storage at the local site is not Dominion’s first choice.
In dry cask storage, spent fuel cooled for at least a year is surrounded by inert gas in casks, which are typically steel cylinders welded or bolted closed.
Monday, March 26, 2012 @ 04:03 PM gHale
Still having major safety issues at a plant that should rid the Hanford nuclear reservation of millions of gallons of radioactive waste, engineers still have no idea just how much waste it will actually be able to treat.
The $12.2 billion plant originally was on tap to dispose of 53 million gallons of nuclear waste, officials told a federal panel late last week.
During a rare public hearing last Thursday, the federal Defense Nuclear Facilities Safety Board, a nuclear-oversight panel appointed by the White House, grilled Hanford contractors and Department of Energy officials about their efforts to build a plant to turn the toxic-nuclear slop in 177 underground tanks into glass after a half-century of bomb making.
Even though the project is half-built, engineers said they still haven’t figured out how, once it is operational, they will keep waste stirred up so it doesn’t spark a nuclear chain reaction.
Officials also are still working out ways to avoid hydrogen explosions in miles of piping and prevent radioactive waste from eating its way through metal tanks in a building that will be so polluted that no human could get inside and make repairs during the 40-year life of the plant.
The safety issues and the insistence by Hanford contractors in recent years they have everything under control infuriated the safety board and other Hanford watchdogs. Safety-board staff member Steven Stokes pointed out the risk of corrosion was an issue as far back as 2001.
“It’s frustrating for us that issues like erosion and corrosion are still coming up at this phase,” said Suzanne Dahl, with the state Department of Ecology’s nuclear-waste program.
Contractors said their search for solutions hasn’t been easy or always gone well. Thomas Patterson, engineering manager for the plant, said because waste in each of Hanford’s underground tanks is a weird concoction of hundreds of chemicals and radionuclides, some problems “could come up again and again and again every time we learn new information about what’s in the tank farm.”
Their answers angered those who have complained that lead contractor Bechtel National and its subcontractors are way behind because their instinct has been to bury safety concerns — and punish those who raise them.
Walt Tamosaitis, a nuclear engineer who works for Hanford contractor URS but says he ended up demoted in 2010 for raising safety concerns, told the board the proposed technical fixes he heard Thursday are years too late.
“I believe some of the answers you’ve heard today would be OK, if this were the first or second year of design,” he said. “But it’s been a decade.”
Without oversight by the safety board, Tamosaitis said, Bechtel “would have proceeded to build a plant that would not work.”
Part of the problem now is the strange mix of waste in each tank will dictate how dangerous the plant is to operate.
So to make sure the plant is safe, engineers may have to rule out processing some volume of the waste, either because it contains high volumes of plutonium or because the mix of chemicals and gases is corrosive or explosive.
That means some as-yet unproven new technologies will have to deal with some of Hanford’s waste.
Wednesday, March 21, 2012 @ 01:03 PM gHale
A crystalline compound that can safely absorb radioactive ions from nuclear waste streams may soon be able to recycle to provide energy for nuclear power.
Notre Dame Thorium Borate-1 (NDTB-1) is the crystalline compound researchers can tailor to absorb radioactive ions from nuclear waste streams and then exchange for higher charged species of a similar size and then recycle it for re-use, according to a paper by researchers at the University of Notre Dame, led by Thomas E. Albrecht-Schmitt, professor of civil engineering and geological sciences and concurrent professor of chemistry and biochemistry.
If one considers the radionuclide technetium (99Tc) is present in the nuclear waste at most storage sites around the world, the math becomes simple. There are more than 436 nuclear power plants operating in 30 countries; that is quite a bit of nuclear waste. In fact, approximately 305 metric tons of 99Tc generated from nuclear reactors and weapons testing from 1943 through 2010. Its safe storage has been an issue for decades.
“The framework of the NDTB-1 is key,” Albrecht-Schmitt said. “Each crystal contains a framework of channels and cages featuring billions of tiny pores, which allow for the interchange of anions with a variety of environmental contaminants, especially those used in the nuclear industry, such as chromate and pertechnetate.”
Albrecht-Schmitt’s team has concluded successful laboratory studies using the NDTB-1 crystals, during which they removed 96 percent of 99Tc.
Additional field tests conducted at the Savannah River National Laboratory in Aiken, SC, showed the Notre Dame compound successfully removes 99Tc from nuclear waste and also exhibits positive exchange selectivity for greater efficiency.
Wednesday, March 14, 2012 @ 02:03 PM gHale
In a move that could help improve clean-up processes for nuclear waste, a new uranium molecule is in development.
The distinctive butterfly-shaped compound is similar to radioactive molecules scientists proposed to be key components of nuclear waste, but they thought were too unstable to exist for long.
However, the compound is robust, which implies that molecules with a similar structure may be present in radioactive waste, researchers said.
This suggests the molecule may play a role in forming clusters of radioactive material in waste that are difficult to separate during clean-up, said scientists at the University of Edinburgh, who conducted the study.
Improving treatment processes for nuclear waste, including targeting this type of molecule, could help the nuclear industry move toward cleaner power generation, where scientists can recover all the radioactive materials from spent fuel and make it safe or used again. This would reduce the amount of waste and curb risks to the environment.
The Edinburgh team worked in collaboration with scientists in the U.S. and Canada to verify the structure of the uranium compound. They made the molecule by reacting a common uranium compound with a nitrogen and carbon-based material. Scientists used chemical and mathematical analyses to confirm the structure of the molecule’s distinctive butterfly shape.
“We have made a molecule that, in theory, should not exist, because its bridge-shaped structure suggests it would quickly react with other chemicals,” said Professor Polly Arnold of the University of Edinburgh’s School of Chemistry. “This discovery that this particular form of uranium is so stable could help optimize processes to recycle valuable radioactive materials and so help manage the UK’s nuclear legacy.”
The Engineering and Physical Sciences Research Council, the EaStCHEM partnership and the University of Edinburgh funded the study.
Monday, August 1, 2011 @ 02:08 PM gHale
Temporary fixes are in line, but overall the United States is not dealing well with finding a real solution to the growing nuclear waste problem, according to a report from a government-appointed body.
The appointed committee, the Blue Ribbon Commission on America’s Nuclear Future, recommends the government free up a $25 billion fund designated for Yucca Mountain in Nevada and use that money to manage its nuclear waste now.
“The Obama Administration’s decision to halt work on a repository at Yucca Mountain in Nevada is but the latest indicator of a policy that has been troubled for decades and has now all but completely broken down,” the committee concluded in its report to the Secretary of Energy.
Congress should create a new government-chartered corporation dedicated to managing the nation’s nuclear waste and then create several geologic disposal and interim storage facilities where they could consolidate and store nuclear waste from the country’s 104 operating reactors, the report said.
The commission, formed by the Secretary of Energy at the request of President Barack Obama, and its subcommittees met more than two dozen times between March 2010 and July 2011 to hear testimony and visit nuclear waste management facilities. The Commission will take comments on the draft through Oct. 31. A final report is due to the Secretary of Energy in January 2012.
Nuclear material stores in fuel assemblies filled with fuel pellets. Each pellet is about the size of a pencil eraser. Once every 18 months to two years, workers remove the head from the vessel that holds the nuclear reactor and move about one third of the fuel into pools to cool. Once there, the fuel must cool for at least five years, according to Nuclear Regulatory Commission (NRC) regulations, before it can move into huge bunker-like “dry casks” for storage. Each cask, roughly the size of a one-car garage, can hold 66 fuel assemblies.
All the fuel produced at a nuclear plant like the Byron Generating Station about 100 miles west of Chicago over 40 years of operation — stacked end to end — would fit in a four-car garage, according to plant owner Exelon. In the U.S. overall, the amount of nuclear waste stored at reactors would cover a football field to a depth of about 20 feet, according to the Blue Ribbon Commission.
The problem for nuclear plant operators is dry casks weren’t a part of the original plan. By now the plan was for the Department of Energy to have taken ownership of that fuel and move it to a permanent federal repository. Utility ratepayers who receive power from nuclear plants have been paying into a fund since 1982 meant to pay for the removal of spent fuel from cooling pools for storage at Yucca Mountain.
But that repository hasn’t materialized and with fuel pools filling up nuclear operators have been removing and babysitting that waste on storage pads outside of reactor buildings. At Byron, the casks can withstand fire and heat up to 1,475 degrees Fahrenheit and tornado winds of up to 360 miles per hour.
While all this has been happening, the $25 billion fund remains untouched and nuclear operators have been successfully suing the government for reimbursement.
“The program they’re paying for just isn’t working,” the Blue Ribbon Commission wrote in its report. “Taxpayers are paying too — in the form of damage payments from the taxpayer-funded Judgment Fund to compensate utilities for the federal government’s failure to meet its contractual waste acceptance commitments.”
The central task of the new government-appointed corporation would be to site, license, build and operate facilities that store nuclear fuel or dispose of it underground, according to the report. The Commission recommends the new organization get direction by a board nominated by the President and confirmed by the Senate.
Wednesday, July 20, 2011 @ 11:07 AM gHale
Radioactive waste from Europe’s 143 nuclear reactors must remain buried deeply in secure bunkers, not in surface containment, European Union ministers said.
The new rules force national nuclear authorities to draw up disposal plans by 2015, which Europe’s energy commissioner Guenther Oettinger will analyze.
The 14 European Union member states using nuclear power currently store the radioactive waste in surface bunkers or warehouses for decades while it cools down.
Russia’s wildfires last summer and, even more recently, the leakage at Japan’s stricken Fukushima plant highlighted the risks posed by surface storage.
Oettinger made nuclear safety one of the main issues of his five-year tenure, pushing ministers to develop a pan-European safety strategy for the first time.
The first step is a series of “stress tests” on nuclear plants, which started in June. The second is Tuesday’s decision to dispose of spent nuclear fuel in secure repositories.
Oettinger’s team, which will vet the national strategies, has already stated its preference for “deep geological repositories,” caverns built in clay or granite rocks between 100 and 700 meters underground.
Safety standards drawn up by the International Atomic Energy Agency will also become legally binding as part of the plan.
Oettinger initially proposed a total ban on exports of radioactive waste to other countries for reprocessing, but ministers created a loophole for future exports. Instead, waste can ship to countries that already have deep geological storage.
“At present, such deep geological repositories do not exist anywhere in the world nor is a repository in construction outside of the EU,” said Oettinger’s team. “It takes currently a minimum of 40 years to develop and build one.”
The EU’s 143 nuclear plants produce about 50,000 cubic meters (1.77 million cu ft) of radioactive waste each year, says nuclear industry body Foratom. About 15 percent of that is high level waste.
Wednesday, June 22, 2011 @ 01:06 PM gHale
Israel returned hundreds of pounds of nuclear waste from its nuclear reactor in Nahal Sorek to the United States, Israeli officials said.
Shaul Horev, the head of Israel’s Nuclear Energy Commission, discussed the return of the material at the International Atomic Energy Agency ministerial conference on nuclear safety in Vienna Monday.
Horev did not specify the exact amount returned but estimates report Israel sent back hundreds of pounds of 93 percent enriched uranium used to power the Sorek reactor, according to a published report.
The return took place under a special U.S. government program to prevent nuclear waste — which a user can recycle and make nuclear weapons — from falling into the hands of terrorist organizations.
The Sorek research reactor is a five-megawatt facility donated to Israel by the United States under former president Dwight Eisenhower’s “Atoms for Peace” program, along with nuclear fuel to power it.
The United States stopped supplying enriched uranium for the Sorek reactor as early as 1977 following a law passed by Congress and because Israel was not a signatory to the Nuclear Non-Proliferation Treaty.
Wednesday, December 8, 2010 @ 06:12 PM gHale
Italy or other countries could soon import their radioactive waste into a Tennessee plant for burning and then transport the ash back to the country of origin.
Energy Solutions, wants to bring 20,000 tons of waste from an old Italian nuclear plant to Oak Ridge, Tenn., and has asked the Nuclear Regulatory Commission to allow German radioactive refuse to ship over here.
The company will take foreign waste only if the country it’s shipped from takes back the ashes or whatever remains after processing, Energy Solutions spokesman Mark Walker said.
EnergySolutions has asked the NRC for a permit to burn 1000 tons of German refuse at its Oak Ridge facility.
“There’ll be waste from universities, hospitals, medical facilities, that will be shipped over, if we receive a permit from the NRC to burn it in the incinerator and then return the ash to Germany,” Walker said.
The company owns a landfill in Clive, Utah. But they will not be able to ship any of the waste there after a U.S. District Court of Appeals ruling prohibiting any of it from going to the Utah landfill.
Whether the Italian waste would come to Tennessee is still up in the air, Walker said.
“The Italian government’s got to determine what they want to do: if they want to send it over as a volume reducer or they just want to keep it where it’s stored right now,” he said.
EnergySolutions is a privately traded, Salt Lake City-based company with $1.5 billion to $2 billion in revenues a year. It does work for the U.S. Department of Energy, Tennessee Valley Authority and others, including operating two nuclear plants for the United Kingdom. It’s also assisting in processing wastes from U.K. nuclear plants in the process of shutting down.
Its facilities in Oak Ridge include a compactor and an incinerator.
Among materials it processes are relatively low-level nuclear waste, including workers’ protective clothing, walls, desks and other equipment from old nuclear plants, as opposed to the highly contaminated used fuel rods from nuclear reactors.
The waste can reduce down by a ratio of 200 to 1, Walker said.
Foreign wastes are nothing new at the facility, he said, adding that radioactive material from Canada has come in, been treated, and the remainder returned.
The company’s new business model includes exploring ways to help countries manage their nuclear wastes within their own borders, he said.