Using of optimization geometric design methods for the problems of the spent nuclear fuel safe storage

2020 ◽  
Vol 25 (3) ◽  
pp. 51-63
Author(s):  
Chugay A.M. ◽  
◽  
Alyokhina S.V. ◽  

Packing optimization problems have a wide spectrum of real-word applications. One of the applications of the problems is problem of placement of containers with spent nuclear fuel (SNF) on the storage platform. The solution of the problem can be reduced to the solution of the problem of finding the optimal placement of a given set of congruent circles into a multiconnected domain taking into account technological restrictions. A mathematical model of the prob-lem is constructed and its peculiarities are considered. Our approach is based on the mathematical modelling of rela-tions between geometric objects by means of phi-function technique. That allowed us to reduce the problem solving to nonlinear programming. Today, an important scientific problem is the problem of creating conditions for safe storage of spent nuclear fuel. In the process of creating any dry spent nuclear fuel storage, the following main stages can be identified: site selection, storage design, construction, operation and decommissioning. A full check for compliance of the repository and its elements with these standards usually begins at the design stage. At the stage of site selection, the inspection for compliance with safety standards is carried out only in terms of the impact of the repository as a whole on the environment. This approach cannot be considered fully appropriate, because, taking into account, for example, all the climatic features of the future storage site, it is possible to adjust the thermal storage regimes of spent nuclear fuel. Similarly, it can be considered necessary to analyze and select the shape of the storage site in order to accommo-date the maximum possible number of spent fuel containers. Such a choice, obviously, should be made taking into ac-count the norms of nuclear, radiation and thermal safety, as well as in compliance with technological limitations. The problem of finding the optimal placement of containers taking into account the given technological limitations can be formulated in the form of the problem of optimization of geometric design. Therefore, the purpose of the study is to build a mathematical model of the problem and study its characteristics to develop effective methods of solution. The proposed approach is based on mathematical modeling of relations between geometric objects using the method of phi-functions. This allowed to reduce the solution of the problem to the problem of nonlinear programming.

Author(s):  
Brett Carlsen ◽  
Denzel Fillmore ◽  
Roger L. McCormack ◽  
Robert Sindelar ◽  
Timothy Spieker ◽  
...  

This report summarizes some of the challenges encountered and solutions implemented to ensure safe storage and handling of damaged spent nuclear fuels (SNF). It includes a brief summary of some SNF storage environments and resulting SNF degradation, experience with handling and repackaging significantly degraded SNFs, and the associated lessons learned. This work provides useful insight and resolutions to many engineering challenges facing SNF handling and storage facilities. The context of this report is taken from a report produced at Idaho National Laboratory and further detailed information, such as equipment design and usage, can be found in the appendices to that report.


Author(s):  
Krista Nicholson ◽  
John McDonald ◽  
Shona Draper ◽  
Brian M. Ikeda ◽  
Igor Pioro

Currently in Canada, spent fuel produced from Nuclear Power Plants (NPPs) is in the interim storage all across the country. It is Canada’s long-term strategy to have a national geologic repository for the disposal of spent nuclear fuel for CANada Deuterium Uranium (CANDU) reactors. The initial problem is to identify a means to centralize Canada’s spent nuclear fuel. The objective of this paper is to present a solution for the transportation issues that surround centralizing the waste. This paper reviews three major components of managing and the transporting of high-level nuclear waste: 1) site selection, 2) containment and 3) the proposed transportation method. The site has been selected based upon several factors including proximity to railways and highways. These factors play an important role in the site-selection process since the location must be accessible and ideally to be far from communities. For the containment of the spent fuel during transportation, a copper-shell container with a steel structural infrastructure was selected based on good thermal, structural, and corrosion resistance properties has been designed. Rail has been selected as the method of transporting the container due to both the potential to accommodate several containers at once and the extensive railway system in Canada.


Author(s):  
Tadahiro Katsuta

Political and technical advantages to introduce spent nuclear fuel interim storage into Japan’s nuclear fuel cycle are examined. Once Rokkasho reprocessing plant starts operation, 80,000 tHM of spent Low Enriched Uranium (LEU) fuel must be stored in an Away From Reactor (AFR) interim storage site until 2100. If a succeeding reprocessing plant starts operating, the spent LEU will reach its peak of 30,000 tHM before 2050, and then will decrease until the end of the second reprocessing plant operation. Throughput of the second reprocessing plant is assumed as twice of that of Rokassho reprocessing plant, indeed 1,600tHM/year. On the other hand, tripled number of final disposal sites for High Level Nuclear Waste (HLW) will be necessary with this condition. Besides, large amount of plutonium surplus will occur, even if First Breeder Reactors (FBR)s consume the plutonium. At maximum, plutonium surplus will reach almost 500 tons. These results indicate that current nuclear policy does not solve the spent fuel problems but rather complicates them. Thus, reprocessing policy could put off the problems in spent fuel interim storage capacity and other issues could appear such as difficulties in large amount of HLW final disposal management or separated plutonium management. If there is no reprocessing or MOX use, the amount of spent fuel will reach over 115,000 tones at the year of 2100. However, the spent fuel management could be simplified and also the cost and the security would be improved by using an interim storage primarily.


2021 ◽  
pp. 277-292
Author(s):  
Ana Radosavljević-Mihajlović ◽  
Vojislav Mitic

Atomic Energy ◽  
2006 ◽  
Vol 101 (1) ◽  
pp. 512-516
Author(s):  
V. G. Aden ◽  
S. Yu. Bulkin ◽  
A. P. Vasil’ev ◽  
N. I. Gontsaryuk ◽  
Yu. A. Ivanov ◽  
...  

Atomic Energy ◽  
2016 ◽  
Vol 119 (5) ◽  
pp. 344-350 ◽  
Author(s):  
S. N. Veselov ◽  
V. I. Volk ◽  
V. A. Kashcheev ◽  
T. V. Podymova ◽  
E. A. Posenitskii

2018 ◽  
pp. 36-40
Author(s):  
S. Alyokhina ◽  
A. Kostikov ◽  
D. Lunov ◽  
O. Dybach ◽  
D. Dimitriieva

The problem of spent nuclear fuel handling in Ukraine is a key issue. A half of spent nuclear fuel is currently stored in Ukraine at the open-site dry storage facility at Zaporizhzhya NPP. Thermal safety analysis should be performed as a part of the storage facility safety assessment. Thermal analysis of a container group is a poorly investigated area. As literature review shows, current results do not clearly identify mutual influence of the containers and influence of weather conditions on the thermal condition of stored spent nuclear fuel. This type of analysis could be performed using the multi-stage methodology proposed by the authors. Thus, mutual thermal influence of the containers and boundary conditions at the inlets to the ventilation duct of each storage container should be identified. Thermal processes in the container group where spent nuclear fuel is stored that are described in this paper are analyzed by solving the conjugate heat transfer problems. A row of containers under wind influence is simulated and the structure of ventilation airflow inside the containers is identified. The mutual thermal influence of the containers is absent under calm conditions, and heated air does not come from one container to another. Resulting from the simulation, boundary conditions at the inlet of the ventilation duct are specified and can be used in the iterative modelling methodology for spent fuel thermal condition. The dependence of the velocity of the inlet ventilation air in the ventilation duct of each  container in the row was defined. The container placement methodology with the purpose of decreasing the wind influence on the thermal condition of spent fuel storage was proposed. Thermal studies are carried out for the containers and storage conditions of the dry spent nuclear storage facility at Zaporizhzhya NPP.


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