scholarly journals A Methodology for Optimizing the Management of Spent Fuel of Nuclear Power Plants Using Dry Storage Casks

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Ian B. Gomes ◽  
Pedro L. Cruz Saldanha ◽  
Antonio Carlos M. Alvim
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Real Life ◽  
Final Decision ◽  
Spent Fuel ◽  
Dry Storage ◽  
Fuel Assemblies ◽  
Intermediate Storage

The management of spent nuclear fuel assemblies of nuclear reactors is a priority subject among member states of the International Atomic Energy Agency. For the majority of these countries, the destination of such fuel assemblies is a decision that is yet to be made and the “wait-and-see” policy is thus adopted by them. In this case, the irradiated fuel is stored in on-site spent fuel pools until the power plant is decommissioned or, when there is no more racking space in the pool, they are stored in intermediate storage facilities, which can be another pool or dry storage systems, until the final decision is made. The objective of this study is to propose a methodology that, using optimization algorithms, determines the ideal time for removal of the fuel assemblies from the spent fuel pool and to place them into dry casks for intermediate storage. In this scenario, the methodology allows for the optimal dimensioning of the designed spent fuel pools and the casks’ characteristics, thus reducing the final costs for purchasing new Nuclear Power Plants (NPP), as the size and safety features of the pool could be reduced and dry casks, that would be needed anyway after the decommissioning of the plant, could be purchased with optimal costs. To demonstrate the steps involved in the proposed methodology, an example is given, one which uses the Monte Carlo N-Particle code (MCNP) to calculate the shielding requirements for a simplified model of a concrete dry cask. From the given example, it is possible to see that, using real-life data, the proposed methodology can become a valuable tool to help making nuclear energy a more attractive choice costwise.

scholarly journals Temperature conditions in the RBMK spent fuel pool in the event of disturbances in its cooling mode

2021 ◽  
Vol 7 (1) ◽  
pp. 9-13
Author(s):  
David A. Hakobyan ◽  
Victor I. Slobodchuk
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Maximum Temperature ◽  
Spent Fuel ◽  
Cooling Mode ◽  
Temperature Conditions ◽  
Fuel Assemblies ◽  
Spent Fuel Pool

The problems of reprocessing and long-term storage of spent nuclear fuel (SNF) at nuclear power plants with RBMK reactors have not been fully resolved so far. For this reason, nuclear power plants are forced to search for new options for the disposal of spent fuel, which can provide at least temporary SNF storage. One of the possible solutions to this problem is to switch to compacted SNF storage in reactor spent fuel pools (SFPs). As the number of spent fuel assemblies (SFAs) in SFPs increases, a greater amount of heat is released. In addition, no less important is the fact that a place for emergency FA discharging should be provided in SFPs. The paper presents the results of a numerical simulation of the temperature conditions in SFPs both for compacted SNF storage and for emergency FA discharging. Several types of disturbances in normal SFP cooling mode are considered, including partial loss of cooling water and exposure of SFAs. The simulation was performed using the ANSYS CFX software tool. Estimates were made of the time for heating water to the boiling point, as well as the time for heating the cladding of the fuel elements to a temperature of 650 °С. The most critical conditions are observed in the emergency FA discharging compartment. The results obtained make it possible to estimate the time that the personnel have to restore normal cooling mode of the spent fuel pool until the maximum temperature for water and spent fuel assemblies is reached.

Interim Storage of Spent Nuclear Fuel in the UAE Nuclear Power Plants

2014 ◽  
Author(s):  
Sara Al Saadi ◽  
Yongsun Yi
Keyword(s):  
Discount Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Spent Fuel ◽  
Cooling Period ◽  
Dry Storage ◽  
Spent Fuel Pool ◽  
Interim Storage

The interim storage options of spent nuclear fuel (SNF) in Barakah nuclear power plants in the UAE were studied in terms of costs and technical issues. Considering the capacity of the spent fuel pools in Barakah nuclear power plants, two scenarios for the interim SNF storage were established. Scenario 1 is ‘minimum use of spent fuel pool’ that SNF will be transferred to dry storage facilities as soon as SNF has been sufficiently cooled down in a pool for the dry storage. Scenario 2 is defined as ‘maximum use of spent fuel pool’ that SNF will be stored in a pool as long as possible till the amount of stored SNF in the pool reaches the capacity of the pools and, then, to be moved for dry storage. For these two scenarios, cost analysis was performed in terms of net present values (NPVs) and levelized unit costs (LUCs). The life cycle of the dry storage was divided into three phases: i) preconstruction phase, ii) construction phase and iii) operation phase. By using data available in literature for the three phases, the total costs were calculated and compared between the two scenarios. For a basic analysis, using the discount rate of 5 % and the required cooling period (Tcool) of 7 years before the SNF transfer to dry storage, LUCs were 184 and 192 $/kg HM for Scenarios 1 and 2, respectively, which were comparable to other analysis results in literature. Then, additional calculations were performed using two different values of the discount rate and the cooling period, respectively. The NPV 1 for Scenario 1 ranges between 175.7 and 413.5 million 2014 $, depending on the discount rate and the cooling period, Tcool. For Scenario 2, NPVs of 85.2 and 237.3 million 2014 $ were obtained for discount rates of 7% and 3%, respectively. The comparisons of the NPVs between the two scenarios showed that Scenario 1 would cost 1.5 to 2.7 times Scenario 2. Technical issues of a dry storage system associated with the site specific conditions in the UAE were also studied. The higher ambient air temperature in the UAE than other countries could affect the cooling capacity of the dry storage by natural convection, which will affect the required cooling period (Tcool) in the spent fuel pool. Also, the harsh environments could have detrimental effects on the integrity of metallic components by degradation phenomena such as pitting, stress corrosion cracking (SCC). This discussion implies that the two aspects related to the harsh environment in the UAE should be studied as early as possible. The environmental and safety impacts associated with the dry storage of SNF were discussed. According to published reports in the USA it seems that there will be no significant environmental impacts of the dry storage for 60 years. However, it is judged that future studies should address the impacts for longer time period than 60 years.

scholarly journals Approaches to Safety Justification for Loading of VSC-VVER Containers in ZNPP DSFSF

2019 ◽  
pp. 82-87
Author(s):  
Ya. Kostiushko ◽  
O. Dudka ◽  
Yu. Kovbasenko ◽  
A. Shepitchak
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
Operating Conditions ◽  
Spent Fuel ◽  
Fuel Assemblies ◽  
Fuel Storage ◽  
The Government

The introduction of new fuel for nuclear power plants in Ukraine is related to obtaining a relevant license from the regulatory authority for nuclear and radiation safety of Ukraine. The same approach is used for spent nuclear fuel (SNF) management system. The dry spent fuel storage facility (DSFSF) is the first nuclear facility created for intermediate dry storage of SNF in Ukraine. According to the design based on dry ventilated container storage technology by Sierra Nuclear Corporation and Duke Engineering and Services, ventilated storage containers (VSC-VVER) filled with SNF of VVER-1000 are used, which are located on a special open concrete site. Containers VSC-VVER are modernized VSC-24 containers customized for hexagonal VVER-1000 spent fuel assemblies. The storage safety assessment methodology was created and improved directly during the licensing process. In addition, in accordance with the Energy Strategy of Ukraine up to 2035, one of the key task is the further diversification of nuclear fuel suppliers. Within the framework of the Executive Agreement between the Government of Ukraine and the U.S. Government, activities have been underway since 2000 on the introduction of Westinghouse fuel. The purpose of this project is to develop, supply and qualify alternative nuclear fuel compatible with fuel produced in Russia for Ukrainian NPPs. In addition, a supplementary approach to safety analysis report is being developed to justify feasibility of loading new fuel into the DSFSF containers. The stated results should demonstrate the fulfillment of design criteria under normal operating conditions, abnormal conditions and design-basis accidents of DSFSF components.  Thus, the paper highlights both the main problems of DSFSF licensing and obtaining permission for placing new fuel types in DSFSF.

Design, Loading, Transport and Storage Experience of CASTOR® Casks for Vitrified High Level Waste

2003 ◽  
Author(s):  
Andre´ Voßnacke ◽  
Wilhelm Graf ◽  
Roland Hu¨ggenberg ◽  
Astrid Gisbertz
Keyword(s):  
Nuclear Power ◽  
High Performance ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
High Level Waste ◽  
Spent Fuel ◽  
Highly Active ◽  
Dry Conditions ◽  
Intermediate Storage ◽  
High Level

The revised German Atomic Act together with the Agreement between the German Government and the German Utilities of June 11, 2001 form new boundary conditions that considerably influence spent fuel strategies by stipulation of lifetime limitations to nuclear power plants and termination of reprocessing. The contractually agreed return of reprocessing residues comprises some 156 casks containing vitrified highly active waste, the so-called HAW or glass canisters, coming form irradiated nuclear fuel assemblies to be shipped from COGEMA, France and BNFL, UK to Germany presumably until 2011. Several hundred casks with compacted residues and other waste will follow. The transports are scheduled presumably beyond 2020. The central interim storage facilities in Ahaus and Gorleben, formerly intended to accumulate up to 8,000 t of heavy metal (HM) of spent fuel from German nuclear power plants, offer sufficient capacity to receive the totality of residues to be returned from reprocessing abroad. GNB has developed, tested, licensed, fabricated, loaded, transported and stored a large number of casks for spent fuel and is one of the world leaders for delivering spent fuel and high level waste casks. Long-term intermediate storage of spent fuel is carried out under dry conditions using these casks that are licensed for transport as well as for storage. Standardized high performance casks such as the types CASTOR® HAW 20/28 CG, CASTOR® V/19 and CASTOR® V/52 meet the needs of most nuclear power plants in Germany. Up to now GNS has co-ordinated the loading and transport of 27 casks loaded with 28 canisters each from COGEMA back to Germany for storage in Gorleben for up to 40 years. In all but one case the cask type CASTOR® HAW 20/28 CG has been used.

scholarly journals Some Characteristics of Hypothetic TVSA with Fuel Enriched beyond 5% for VVER1000

2016 ◽  
pp. 22-26
Author(s):  
Ye. Bilodid ◽  
Yu. Kovbasenko
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Safety ◽  
Management Systems ◽  
Design Parameters ◽  
Spent Fuel ◽  
Fuel Management ◽  
Severe Accidents ◽  
Fuel Assemblies

The paper presents comparison of regular TVSA with average enrichment of 4,386% and hypothetical TVSA with enrichment of 10% based on design parameters and materials of TVSA fuel assemblies produced by TVEL (Russia), which today are widely used at nuclear power plants in Ukraine. It is shown that implementation of new fuel assemblies will result in improved use of fuel and increase of installed capability factor. At the same time, fresh and spent fuel management systems shall be modernized to meet relevant nuclear safety criteria. The paper analyzes possible criticality initiation at different stages of severe accidents related to core melt and using fuel with higher enrichment.

scholarly journals Prevention of Damage to Spent Nuclear Fuel during Handling Operations

2020 ◽  
pp. 62-71
Author(s):  
M. Sapon ◽  
O. Gorbachenko ◽  
S. Kondratyev ◽  
V. Krytskyy ◽  
V. Mayatsky ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Spent Fuel ◽  
Long Term Storage ◽  
Fuel Storage ◽  
Storage Facilities

According to regulatory requirements, when carrying out handling operations with spent nuclear fuel (SNF), prevention of damage to the spent fuel assemblies (SFA) and especially fuel elements shall be ensured. For this purpose, it is necessary to exclude the risk of SFA falling, SFA uncontrolled displacements, prevent mechanical influences on SFA, at which their damage is possible. Special requirements for handling equipment (in particular, cranes) to exclude these dangerous events, the requirements for equipment strength, resistance to external impacts, reliability, equipment design solutions, manufacturing quality are analyzed in this work. The requirements of Ukrainian and U.S. regulatory documents also are considered. The implementation of these requirements is considered on the example of handling equipment, in particular, spent nuclear fuel storage facilities. This issue is important in view of creation of new SNF storage facilities in Ukraine. These facilities include the storage facility (SFSF) for SNF from water moderated power reactors (WWER): a Сentralized SFSF for storing SNF of Rivne, Khmelnitsky and South-Ukraine Nuclear Power Plants (СSFSF), and SFSF for SNF from high-power channel reactors (RBMK): a dry type SFSF at Chornobyl nuclear power plant (ISF-2). After commissioning of these storage facilities, all spent nuclear fuel from Ukrainian nuclear power plants will be placed for long-term “dry” storage. The safety of handling operations with SNF during its preparation for long-term storage is an important factor.

Safety Aspects in Dry Storage of Spent Nuclear Fuel in Long Term Operation for Brazilian Nuclear Power Plants

2020 ◽  
Vol 18 (10) ◽  
pp. 1807-1816
Author(s):  
Claudir Jose Nodari ◽  
Pedro Luiz da Cruz Saladanha ◽  
Gladson Silva Fontes
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Term Operation ◽  
Dry Storage ◽  
Safety Aspects

NUCLEAR WASTE MANAGEMENT IN SPAIN: ANALYSIS OF THE CURRENT SITUATION AND ALTERNATIVE STRATEGIES

10.6036/10156 ◽  
2021 ◽  
Vol 96 (4) ◽  
pp. 355-358
Author(s):  
Pablo Fernández Arias ◽  
DIEGO VERGARA RODRIGUEZ
Keyword(s):  
Nuclear Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Fuel ◽  
Nuclear Waste Storage ◽  
Alternative Strategies ◽  
Temporary Storage ◽  
Long Term Storage ◽  
High Level

Centralized Temporary Storage Facility (CTS) is an industrial facility designed to store spent fuel (SF) and high level radioactive waste (HLW) generated at Spanish nuclear power plants (NPP) in a single location. At the end of 2011, the Spanish Government approved the installation of the CTS in the municipality of Villar de Cañas in Cuenca. This approval was the outcome of a long process of technical studies and political decisions that were always surrounded by great social rejection. After years of confrontations between the different political levels, with hardly any progress in its construction, this infrastructure of national importance seems to have been definitively postponed. The present research analyzes the management strategy of SF and HLW in Spain, as well as the alternative strategies proposed, taking into account the current schedule foreseen for the closure of the Spanish NPPs. In view of the results obtained, it is difficult to affirm that the CTS will be available in 2028, with the possibility that its implementation may be delayed to 2032, or even that it may never happen, making it necessary to adopt an alternative strategy for the management of GC and ARAR in Spain. Among the different alternatives, the permanence of the current Individualized Temporary Stores (ITS) as a long-term storage strategy stands out, and even the possibility of building several distributed temporary storage facilities (DTS) in which to store the SF and HLW from several Spanish NPP. Keywords: nuclear waste, storage, nuclear power plants.

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