scholarly journals Multiobjective Mixed Integer Nonlinear Model to Plan the Schedule for the Final Disposal of the Spent Nuclear Fuel in Finland

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 528
Author(s):  
Outi Montonen ◽  
Ville-Pekka Eronen ◽  
Timo Ranta ◽  
Jani A. S. Huttunen ◽  
Marko M. Mäkelä

The safe disposal of the spent nuclear fuel is the important part of the nuclear power production. In this paper, we model the geological disposal in Finland covering objectives related to the interim storage, the encapsulation facility, the disposal facility, and the costs. A notable fact is that all the fuel types used in Finland are taken into account. The resulting optimization model is of a multiobjective nonlinear mixed integer type having eight objectives. The model is solved with the interactive method utilizing the special type of the achievement scalarizing functions. From this, we obtain a disposal schedule giving amounts of canisters to encapsulate in each time period. The results obtained are analyzed from the practical point of view.

Algorithms ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 252 ◽  
Author(s):  
Outi Montonen ◽  
Timo Ranta ◽  
Marko M. Mäkelä

Several countries utilize nuclear power and face the problem of what to do with the spent nuclear fuel. One possibility, which is under the scope in this paper, is to dispose of the fuel assemblies in the disposal facility. Before the assemblies can be disposed of, they must cool down their decay heat power in the interim storage. Next, they are loaded into canisters in the encapsulation facility, and finally, the canisters are placed in the disposal facility. In this paper, we model this process as a nonsmooth multiobjective mixed-integer nonlinear optimization problem with the minimization of nine objectives: the maximum number of assemblies in the storage, maximum storage time, average storage time, total number of canisters, end time of the encapsulation, operation time of the encapsulation facility, the lengths of disposal and central tunnels, and total costs. As a result, we obtain the disposal schedule i.e., amount of canisters disposed of periodically. We introduce the interactive multiobjective optimization method using the two-slope parameterized achievement scalarizing functions which enables us to obtain systematically several different Pareto optimal solutions from the same preference information. Finally, a case study adapting the disposal in Finland is given. The results obtained are analyzed in terms of the objective values and disposal schedules.


Author(s):  
Masumi Wataru ◽  
Hisashi Kato ◽  
Satoshi Kudo ◽  
Naoko Oshima ◽  
Koji Wada ◽  
...  

Spent nuclear fuel coming from a Japanese nuclear power plant is stored in the interim storage facility before reprocessing. There are two types of the storage methods which are wet and dry type. In Japan, it is anticipated that the dry storage facility will increase compared with the wet type facility. The dry interim storage facility using the metal cask has been operated in Japan. In another dry storage technology, there is a concrete overpack. Especially in USA, a lot of concrete overpacks are used for the dry interim storage. In Japan, for the concrete cask, the codes of the Japan Society of Mechanical Engineers and the governmental technical guidelines are prepared for the realization of the interim storage as well as the code for the metal cask. But the interim storage using the concrete overpack has not been in progress because the evaluation on the stress corrosion cracking (SCC) of the canister is not sufficient. Japanese interim storage facilities would be constructed near the seashore. The metal casks and concrete overpacks are stored in the storage building in Japan. On the other hand, in USA they are stored outside. It is necessary to remove the decay heat of the spent nuclear fuel in the cask from the storage building. Generally, the heat is removed by natural cooling in the dry storage facility. Air including the sea salt particles goes into the dry storage facility (Figure 1). Concerning the concrete overpack, air goes into the cask body and cools the canister. Air goes along the canister surface and is in contact with the surface directly. In this case, the sea salt in the air attaches to the surface and then there is the concern about the occurrence of the SCC. For the concrete overpack, the canister including the spent fuel is sealed by the welding. The loss of sealability caused by the SCC has to be avoided. To evaluate the SCC for the canister, it is necessary to make clear the amount of the sea salt particles coming into the storage building and the concentration on the canister. In present, the evaluation on that point is not sufficient. In this study, the concentration of the sea salt particles in the air and on the surface of the storage facility are measured inside and outside of the building. For the measurement, two sites of the dry storage facility using the metal cask are chosen. This data is applicable for the evaluation on the SCC of the canister to realize the interim storage using the concrete overpack.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4869
Author(s):  
Joaquín Bautista-Valhondo ◽  
Lluís Batet ◽  
Manuel Mateo

The paper assumes that, at the end of the operational period of a Spanish nuclear power plant, an Independent Spent Fuel Storage Installation will be used for long-term storage. Spent fuel assemblies are selected and transferred to casks for dry storage, with a series of imposed restrictions (e.g., limiting the thermal load). In this context, we present a variant of the problem of spent nuclear fuel cask loading in one stage (i.e., the fuel is completely transferred from the spent fuel pool to the casks at once), offering a multi-start metaheuristic of three phases. (1) A mixed integer linear programming (MILP-1) model is used to minimize the cost of the casks required. (2) A deterministic algorithm (A1) assigns the spent fuel assemblies to a specific region of a specific cask based on an MILP-1 solution. (3) Starting from the A1 solutions, a local search algorithm (A2) minimizes the standard deviation of the thermal load among casks. Instances with 1200 fuel assemblies (and six intervals for the decay heat) are optimally solved by MILP-1 plus A1 in less than one second. Additionally, A2 gets a Pearson’s coefficient of variation lower than 0.75% in less than 260s CPU (1000 iterations).


2021 ◽  
Vol 13 (3) ◽  
pp. 41
Author(s):  
Р.М. Яковлев ◽  
И.А. Обухова

Large-scale nuclear energetics can satisfy demands for all kinds of energy, i.e. it can secure energy safety of Russia and the whole humankind; however, this is associated with a number of daunting problems. With that, this approach is a priority for Russia. The State Corporation RosAtom is involved in the development of nuclear reactors in Russia and abroad on the conditions that the reactors will be supplied with nuclear fuel from Russia and the spent fuel will be returned to Russia for conversion into mixed uranium and plutonium oxide (MOX) fuel. In the city Zheleznogorsk near Krasnoyarsk, the first production line of a plant for treating 2000 tons of spent nuclear fuel annually has been already launched. The principal strategic plan of RosAtom, which has been being realized currently, is to develop nuclear power production based on fuel recycling using fast neutron reactors for generation of plutonium, which may be used in nuclear weapons and is most hazardous for the biosphere. The possibility of accidents associated with radioactive discharges cannot be excluded, and the hazardousness of such accidents in increased by using plutonium-based fuels. The nuclear power-based approach to energy production is costly but also dangerous not only for Russia.


2020 ◽  
Vol 207 ◽  
pp. 01024
Author(s):  
Petar Paunov ◽  
Ivaylo Naydenov

One of the main concerns related to nuclear power production is the generation and accumulation of spent nuclear fuel. Currently most of the spent fuel is stored in interim storage facilities awaiting final disposal or reprocessing. The spent fuel is stored in isolation from the environment in protected facilities or specially designed containers. Nevertheless, spent fuel and highly active waste might get in the environment in case the protective barriers are compromised. In such a case, spent fuel may pose risk to the environment and human health. Those risks depend on the concentration of the given radionuclide and are measured by the value of potential danger. The potential danger is called also ’radiotoxicity’. The paper examines spent uranium and MOX fuels from a reference PWR, as well as the highly radioactive wastes of their reprocessing. The radiotoxicity of the four materials is examined and evaluated for a cooling time of 1000 years. The contribution of different radionuclides is assessed and the cases of reprocessing and no reprocessing of spent fuel have been compared.


2021 ◽  
Author(s):  
Ryan M. Meyer ◽  
Jeremy Renshaw ◽  
Jamie Beard ◽  
Jon Tatman ◽  
Matt Keene ◽  
...  

Abstract This paper describes development and demonstration of remote crawling systems to support periodic examinations of interim dry storage system (DSS) canisters for spent nuclear fuel in the USA. Specifically, this work relates to robotic crawler developments for “canister” based DSS systems, which form the majority population of DSSs in the USA for interim storage of spent nuclear fuel. Consideration of potential degradation of the welded stainless-steel canister in these systems is required for continued usage in the period of extended operation (PEO) beyond their initial licensed or certified terms. Challenges with performing the periodic examinations are associated with physical access to the canister surface, which is constrained due to narrow annulus spaces between the canister and the overpack, tortuous entry pathways, and high temperatures and radiation doses that can be damaging to materials and electronics. Motivations for performing periodic examinations and developing robotic crawlers for performing those examinations remotely will be presented, and several activities to demonstrate robotic crawlers for different DSS systems are summarized.


1980 ◽  
Vol 7 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Asit K. Biswas

Discussions on environmental implications of nuclear energy have so far been concentrated on radiological aspects: disposal of radioactive wastes, safety of nuclear power production, safe handling of plutonium, and problems associated with uranium mining. There are, however, several environmental issues associated with nuclear power production that are non-radiological in nature: thermal pollution and attendant effects on aquatic life, problems associated with land-use requirements, aesthetic considerations, habitat alterations, and atmospheric effects. These different non-radiological environmental implications of nuclear energy are reviewed.The paper concludes that, while there are some environmental problems which exist at present, and a few more could emerge in the future, all these problems appear to be solvable with the present state of technological development. The extent of environmental degradation can be significantly reduced by appropriate design and planning.


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