Texas solution or nuclear nightmare? : as a company in the Lone Star State moves to profit from America's dilemma with spent nuclear fuel, others fear the worst

textThe United States government has sought a permanent disposal site for spent nuclear fuel since 1982. To date, no location for disposing of spent fuel exists. The situation is problematic, because spent nuclear fuel is a high-level radioactive waste. It is a byproduct of nuclear power plants' electricity production. It is also incredibly dangerous material. With the government set to continue relying on the nuclear industry for electricity, the amount of spent nuclear fuel in the United States will continue to grow. Waste Control Specialists, a company headquartered in Dallas, Texas that specializes in low-level nuclear waste disposal, is in the process of applying for a Nuclear Regulatory Commission license to temporarily store spent fuel in Andrews, Texas. If successful, WCS could earn millions of dollars. Company officials are promoting the plan as a solution for America, but opinions from industry experts and residents near Andrews conflict over the safety of transporting and storing spent fuel in Texas.Journalis

The Classification of Weld Seam Defects for Quantitative Analysis by means of Ultrasonic Testing

The paper describes effective quality assessment of spent nuclear fuel storage cask. The ultrasonic testing method is considered. The classification of possible defects with corresponding dimensions limits is proposed. The database of defects of the spent nuclear fuel storage cask was created in compliance with the nuclear energy industry regulatory documents

The Classification of Weld Seam Defects for Quantitative Analysis by means of Ultrasonic Testing

The paper describes effective quality assessment of spent nuclear fuel storage cask. The ultrasonic testing method is considered. The classification of possible defects with corresponding dimensions limits is proposed. The database of defects of the spent nuclear fuel storage cask was created in compliance with the nuclear energy industry regulatory documents

INTERROGATION OF SPENT NUCLEAR FUEL CASKS USING COSMIC-RAY MUON COMPUTED TOMOGRAPHY

Properly accounting and safeguarding spent nuclear fuel are key components in the International Atomic Energy Agency’s mission of non-proliferation. Currently, no instruments are deployed that are able to verify the spent nuclear fuel contents of dry storage casks. Cosmic-ray muons provide an ideal probe for the heavily shielded casks due to their ability to penetrate thick, dense materials. Coulombic scattering of the muons, to first order, is proportional to the Z2/A of the material; this makes it especially sensitive to actinides, such as uranium and plutonium. The combination of these traits allows muons to be used to image and verify the contents of a sealed cask in situ. Here the analysis of the first muon scattering measurements of spent nuclear fuel dry casks is presented, which show a 2.3 σ confidence in the identification of a missing fuel bundle. Geant4 simulations are benchmarked against measurement data and show good agreement. Using the benchmarked simulations, the first study of computed tomography using cosmic-ray muon scattering is presented and further applied to the fingerprinting and monitoring of spent nuclear fuel casks. Finally, the feasibility of using cosmic-ray muons to perform a final verification of spent nuclear fuel-prior to permanent deposition in a geological repository-is investigated

Risk communication between experts and the public: perceptions and intentions

This paper develops a conceptual and theoretical analysis of risk communication in cases where experts and the public have widely divergent views of the dimensions of a risk. Applications are chosen from among the risk management problems that are inherent to handling of spent nuclear fuel. One stresses the fact that the conflicting points of views have very different bases. The role of trust is analyzed and, as it is a crucial issue, it becomes much more encompassing than what has usually been assumed. The reasons for this difference can be found in risk perception models applied to survey data concerning risk perception and related attitudes.risk perception; siting; nuclear waste; spent nuclear fuel

Capturing Heat from Spent Nuclear Fuel

ME450 Capstone Design and Manufacturing Experience: Winter 2021Spent Nuclear Fuel can be placed in dry cask storage, where it emits waste heat into the atmosphere. Our sponsor, Dr. Marianna Coulentianos, identified an opportunity to capture this heat for a beneficial application. Our team evaluated the feasibility of our sponsor’s previously proposed solutions and designed a system that could transfer heat from the dry cask. We focused specifically on quantifying the amount of heat that would be available for a therothecial application. In order to determine how much heat would theoretically be available, we constructed both mathematical and computational simulations of heat transfer through a duct system. The system we propose includes a square funnel feature at the cask interface, connected to a round, rigid duct system extending over the perimeter fence. It was observed that the outlet temperature of our proposed system is around 36-65℃, which we determined is most suitable for a greenhouse application. We calculated a return on investment of 5 years by growing tomatoes in a greenhouse of 1800 ft2. We are confident that our design is feasible and does not violate any regulations set forth by the Nuclear Regulatory Commission. However, more analysis is needed to further examine discrepancies between field data and our assumptions, as well as the scalability of our proposed solution. We also considered the social context of this solution. Eating fruits and vegetables grown on a nuclear site is likely to cause skepticism around our solution. While we believe that the radiation levels of this waste heat are too low to realistically affect horticultural applications, all food that is intended for human or animal consumption in the United States must register with the FDA before beginning these activities.Dr. Marianna Coulentianos: UM Mechanical Engineering Departmenthttp://deepblue.lib.umich.edu/bitstream/2027.42/167636/1/Team_17-Capturing_Heat_from_Spent_Nuclear_Fuel.pd

Opening of Nitride Spent Nuclear Fuel

Nitride nuclear fuel (UN + 10-20% PuN) is considered a promising alternative to the widely used oxide nuclear fuel (UO2). Thermal conductivity and density of nitride fuel are ∼ 7 times and 1.3 times higher than that of oxide fuel, respectively. Nitride fuel demonstrates a good compatibility with the cladding of fuel rods made of stainless steel. Along with the development of new fuel, methods for its subsequent processing are being developed. Various options for the initial opening of nitride spent nuclear fuel (SNF) are considered in this article. The use of gaseous chlorine is technologically inconvenient and dangerous when working with radioactive substances. The electrochemical dissolution of nitride SNF cannot be realized due to the formation of a by-product - UNCl. Uranium nitride chloride is an insulator and it blocks the electrochemical process. It was found that the chlorination of nitride SNF with cadmium or lead chlorides makes it possible to carry out 100% UN → UCl3 conversion. The use of voloxidation (oxidation of nitride SNF to oxides) as the first stage of processing will make the entire technology universal, suitable for processing both nitride and oxide SNF. The choice of the method for opening SNF depends on the choice of the subsequent stages of its processing. Keywords: nitride spent nuclear fuel, SNF, chlorination, anodic dissolution, UNCl, “soft” chlorination, voloxidation, processin

Cosmic ray muons for spent nuclear fuel monitoring

There is a steady increase in the volume of spent nuclear fuel stored on-site (at reactor) as currently there is no permanent disposal option. No alternative disposal path is available and storage of spent nuclear fuel in dry storage containers is anticipated for the near future. In this dissertation, a capability to monitor spent nuclear fuel stored within dry casks using cosmic ray muons is developed. The motivation stems from the need to investigate whether the stored content agrees with facility declarations to allow proliferation detection and international treaty verification. Cosmic ray muons are charged particles generated naturally in the atmosphere from high energy cosmic rays. Using muons for proliferation detection and international treaty verification of spent nuclear fuel is a novel approach to nuclear security that presents significant advantages. Among others, muons have the ability to penetrate high density materials, are freely available, no radiological sources are required and consequently there is a total absence of any artificial radiological dose. A methodology is developed to demonstrate the applicability of muons for nuclear nonproliferation monitoring of spent nuclear fuel dry casks. Purpose is to use muons to differentiate between spent nuclear fuel dry casks with different amount of loading, not feasible with any other technique. Muon scattering and transmission are used to perform monitoring and imaging of the stored contents of dry casks loaded with spent nuclear fuel. It is shown that one missing fuel assembly can be distinguished from a fully loaded cask with a small overlapping between the scattering distributions with 300,000 muons or more. A Bayesian monitoring algorithm was derived to allow differentiation of a fully loaded dry cask from one with a fuel assembly missing in the order of minutes and negligible error rate. Muon scattering and transmission simulations are used to reconstruct the stored contents of sealed dry casks from muon measurements. A combination of muon scattering and muon transmission imaging can improve resolution and thus a missing fuel assembly can be identified for vertical and horizontal dry casks. The apparent separation of the images reveals that the muon scattering and transmission can be used for discrimination between casks, satisfying the diversion criteria set by IAEA

Physical modeling of spent-nuclear-fuel container

A new physical simulation model was developed to simulate the casting process of the ductile iron heavy section spent-nuclear-fuel container. In this physical simulation model, a heating unit with DR24 Fe-Cr-Al heating wires was used to compensate the heat loss across the non-natural surfaces of the sample, and a precise and reliable casting temperature controlling/monitoring system was employed to ensure the thermal behavior of the simulated casting to be similar to the actual casting. Also, a mould system was designed, in which changeable mould materials can be used for both the outside and inside moulds for different applications. The casting test was carried out with the designed mould and the cooling curves of central and edge points at different isothermal planes of the casting were obtained. Results show that for most isothermal planes, the temperature control system can keep the temperature differences within 6 ℃ between the edge points and the corresponding center points, indicating that this new physical simulation model has high simulation accuracy, and the mould developed can be used for optimization of casting parameters of spent-nuclear-fuel container, such as composition of ductile iron, the pouring temperature, the selection of mould material and design of cooling system. In addition, to maintain the spheroidalization of the ductile iron, the force-chilling should be used for the current physical simulation to ensure the solidification of casting in less than 2 h

Ultrasonic inspection of spent nuclear fuel casks

The paper describes the main aspects of ultrasonic non-destructive inspection of casks with spent fuel. Digital Focus Array technique is proposed for acoustic imaging of spent nuclear fuel casks' closure weld. Scientific and engineering basics and imaging algorithms of this technique are discussed. Advantages of Digital Focus Array technique in comparison with common techniques of acoustic images processing are revealed