Nuclear Power Plants, Nuclear Fuel Processing P...
Nuclear power plants use energy released by the decay of certain radioactive isotopes to produce electricity. Additional radioactive isotopes are produced during this process. In nuclear power plants, specially designed fuel rods and containment structures enclose the radioactive materials to prevent them, and the ionizing radiation they produce, from contaminating the environment. If the fuel and surrounding containment structures are severely damaged, radioactive materials and ionizing radiation may be released, potentially posing a health risk for people. The actual risk depends on
Nuclear Power Plants, Nuclear Fuel Processing p...
The radioactive isotopes released in nuclear power plant accidents include iodine-131 (I-131), cesium-134 (Cs-134), and Cs-137. In the most severe kinds of accidents, such as the Chernobyl accident in 1986, other dangerous radioactive isotopes, such as strontium-90 (Sr-90) and plutonium-239, may also be released.
Human exposure to I-131 released from nuclear power plant accidents comes mainly from consuming contaminated water, milk, or foods. People may also be exposed by breathing dust particles in the air that are contaminated with I-131.
Much of what is known about cancer caused by radiation exposures from nuclear power plant accidents comes from research on the April 1986 nuclear power plant disaster at Chernobyl in Ukraine (Chornobyl in Ukrainian) (1, 2). The radioactive isotopes released during the Chernobyl accident included I-131, Cs-134, Cs-137, and Sr-90.
Cancer patients who are being treated with systemic chemotherapy or radiation therapy should be evacuated from the area where a nuclear power plant accident has occurred so their medical treatment can continue without interruption. Patients should always keep a record of the treatments they have had in the past and that they may be currently receiving, including the names of any drugs and their doses. These records may be important in the aftermath not only of a nuclear power plant accident but also after other large-scale events that may disrupt medical services, when medical records may be lost.
The administration of George W. Bush proposed that the United States could build a reprocessing plant without encouraging the spread of such plants if the United States and other countries that currently reprocess offered reprocessing services to the non-nuclear-weapon states. France, Russia, and the United Kingdom already have tried that, however, and it failed because of the cost and the unwillingness of the reprocessing countries to keep the reprocessing waste.
More importantly from an international security perspective, pyroprocessing would make plutonium much more accessible, exacerbating the danger of nuclear weapons proliferation. If reprocessing does not facilitate radioactive waste management and is costly and proliferative, it would be far better for the number of countries that are reprocessing to continue to decline rather than to add a second non-nuclear-weapon state to their number.
Given the inherently low danger from stored spent fuel that has cooled for about two decades in comparison with that from the fuel in an operating nuclear power plant or freshly discharged fuel in at-reactor spent-fuel cooling pools, it is quite possible that, if the compensation were comparable to what Aomori Prefecture is receiving for hosting the Rokkasho Reprocessing Plant, a jurisdiction already hosting a nuclear power plant might be willing to host an interim spent fuel storage site as well. The cost would still be small in comparison to the estimated 11 trillion yen ($100 billion) cost of building, operating, and decommissioning the Rokkasho Reprocessing Plant. In fact, in Sweden and Finland, local jurisdictions that already host nuclear power plants have volunteered to host deep-underground spent-fuel repositories.
Far better would be to restrict the focus of collaborative R&D to reactor types that do not require reprocessing. Collaboration on nuclear energy among China, Japan, and South Korea would be especially useful for trust building and nonproliferation in East Asia.
What is needed especially is multinational cooperation in the sensitive parts of the nuclear fuel cycle that are required by current-generation reactors operating on a once-through fuel cycle, namely uranium enrichment and spent fuel repositories.
Minnesota has two nuclear power generating facilities that have been in operation since the early 1970s: the Prairie Island Nuclear Generating Plant (Unit 1, Unit 2) and the Monticello Nuclear Generating Plant. The issue of how and where to store nuclear waste first came to the forefront in Minnesota in the late 1980s and began at the Prairie Island facility.
At that time, Prairie Island's high-level spent radioactive waste was stored in stainless steel-lined concrete vaults that were surrounded by cooling water. Under provisions of the Nuclear Waste Policy Act of 1982, the U.S. Government was to develop a site that would accept radioactive waste from the country's nuclear power plants beginning on January 31, 1998. By the late 1980s, with a nuclear waste repository years from completion and Prairie Island facing the prospect of having to close for lack of storage space, Northern States Power (NSP) (now known as Xcel Energy) asked the Minnesota Environmental Quality Board (EQB) for permission to store additional waste in dry casks at the Prairie Island site. In May 1990, the board called for an environmental impact study of the proposed dry cask storage. In the spring of 1991 the EQB approved and released the Final Environmental Impact Statement: Prairie Island Independent Spent Fuel Storage Installation.
In that law was a provision prohibiting the construction of any additional nuclear-powered electrical generating plants in the state (Minnesota Statutes 216B.243, subdivision 3b). There have been numerous bills introduced since then seeking to repeal the construction prohibition, including HF1400/SF306 in the 2015/2016 legislative session. None of the bills have passed and the moratorium on nuclear power plant construction remains in effect.
In 1998, after the U.S. Department of Energy failed to meet the January 31, 1998 deadline to accept waste from the country's nuclear power plants, NSP filed a lawsuit in the U.S. Court of Federal Claims against the department, seeking reimbursement for the costs of storing the waste at its Minnesota facilities. The suit was settled in September 2007, with Xcel Energy/NSP being awarded $116 million for costs accrued through 2004. In August 2007, Xcel Energy filed another lawsuit against the U.S. Department of Energy seeking money to cover waste storage costs from 2005 through June 2007. In a July 2011 settlement, Xcel Energy was awarded $100 million for fuel storage costs at Prairie Island and Monticello through 2008. The settlement also would pay for actual costs incurred from 2009 to 2013.
The next request for additional waste storage came in January 2005 when Xcel Energy filed an application for a certificate of need with the Minnesota PUC to build a nuclear waste storage facility at the Monticello plant. In June 2005, the Minnesota Environmental Quality Board approved an EIS Scoping Decision that outlined the issues and the alternatives to be examined as part of a required environmental impact study (EIS). A Draft EIS was issued in November 2005 and a Final EIS in March 2006, followed by an Adequacy Determination on July 26, 2006, by the Minnesota Department of Commerce. On August 4, 2006, Administrative Law Judge Steve M. Mihalchick issued a ruling on Xcel Energy's Certificate of Need application concluding, "It is respectfully recommended that the Public Utilities Commission issue a Certificate of Need to Xcel Energy for the construction and operation of a dry spent fuel storage facility at the Monticello generating plant with up to 30 spent fuel containers, vaults, and associated equipment necessary to allow the Monticello generating plant to continue in operation through 2030." On September 28, 2006, the PUC approved Xcel Energy's request for nuclear waste storage at the Monticello facility and an order approving the Certificate of Need was issued on October 23, 2006. The decision was effective in June 2007 and construction was planned to begin later that year.
The removal of volatile radionuclides generated during used nuclear fuel reprocessing in the US is almost certain to be necessary for the licensing of a reprocessing facility in the US. Various control technologies have been developed, tested, or used over the past 50 years for control of volatile radionuclide emissions from used fuel reprocessing plants. The US DOE has sponsored, since 2009, an Off-gas Sigma Team to perform research and development focused on the most pressing volatile radionuclide control and immobilization problems. In this paper, we focus on the control requirements and methodologies for 85Kr and 129I. Numerous candidate technologies have been studied and developed at laboratory and pilot-plant scales in an effort to meet the need for high iodine control efficiency and to advance alternatives to cryogenic separations for krypton control. Several of these show promising results. Iodine decontamination factors as high as 105, iodine loading capacities, and other adsorption parameters including adsorption rates have been demonstrated under some conditions for both silver zeolite (AgZ) and Ag-functionalized aerogel. Sorbents, including an engineered form of AgZ and selected metal organic framework materials (MOFs), have been successfully demonstrated to capture Kr and Xe without the need for separations at cryogenic temperatures.
Radionuclides that tend to form volatile species evolve into reprocessing facility off-gas systems and are more challenging to be efficiently controlled compared to radionuclides that remain with the solids or liquids during fuel reprocessing. Unless otherwise managed, these radionuclides would be released to the environment. It is nearly certain that for any future used nuclear fuel (UNF) reprocessing facilities to meet licensing requirements in the United States, efficient capture of some volatile radionuclides from the plant off-gas streams will be needed. 041b061a72