scholarly journals Long-Term Radiotoxicity Evaluation of PWR Spent Uranium and MOX Fuel and Highly Active Waste

2020 ◽  
Vol 207 ◽  
pp. 01024
Author(s):  
Petar Paunov ◽  
Ivaylo Naydenov
Keyword(s):  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Potential Danger ◽  
Spent Fuel ◽  
Highly Active ◽  
Active Waste ◽  
Interim Storage ◽  
The Given ◽  
Nuclear Power Production

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.

Measurement of Atmospheric Sea Salt Concentration in the Dry Storage Facility of the Spent Nuclear Fuel

2006 ◽  
Author(s):  
Masumi Wataru ◽  
Hisashi Kato ◽  
Satoshi Kudo ◽  
Naoko Oshima ◽  
Koji Wada ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Sea Salt ◽  
Storage Facility ◽  
Japan Society ◽  
Spent Fuel ◽  
Dry Storage ◽  
Storage Methods ◽  
Interim Storage

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.

scholarly journals ПЕРСПЕКТИВЫ АТОМНОЙ ЭНЕРГЕТИКИ В ОБЕСПЕЧЕНИИ ЭНЕРГЕТИЧЕСКОЙ И ЭКОЛОГИЧЕСКОЙ БЕЗОПАСНОСТИ РОССИИ

2021 ◽  
Vol 13 (3) ◽  
pp. 41
Author(s):  
Р.М. Яковлев ◽  
И.А. Обухова
Keyword(s):  
Nuclear Fuel ◽  
Energy Production ◽  
Nuclear Power ◽  
Large Scale ◽  
Spent Nuclear Fuel ◽  
Spent Fuel ◽  
Mox Fuel ◽  
State Corporation ◽  
The City ◽  
Nuclear Power Production

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.

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.

CONSTOR® Transport and Storage Cask for Spent Fuel and for High Active Waste

2001 ◽  
Author(s):  
Rudolf Diersch ◽  
Robert Gartz ◽  
Konrad Gluschke
Keyword(s):  
Nuclear Power ◽  
Type B ◽  
Spent Fuel ◽  
The Czech Republic ◽  
Active Waste ◽  
Intermediate Storage ◽  
Near Future ◽  
And Storage ◽  
Rbmk Fuel

Abstract The CONSTOR® was developed with special consideration to an economical and effective way of manufacturing by using conventional mechanical engineering technologies and common materials. The main objective of this development was to fabricate these casks in countries not having highly specialized industries for casting or forging of thick-walled casks. Nevertheless, the CONSTOR® concept fulfills both the internationally valid IAEA criteria for transportation and the German criteria for long-term intermediate storage. The basic cask concept has been designed for adaptation to different spent fuel specifications as well as handling conditions in the NPPs. Adaptations have been made for spent fuel from RBMK and VVER reactors, and also for BWR spent fuel and high active waste. So far, 30 CONSTOR® RBMK-1500 original casks have been manufactured and delivered to Ignalina Nuclear Power Plant in Lithuania. Two of these have been succesfully loaded during hot trial tests and placed in storage. The CONSTOR® cask for RBMK fuel has obtained the type B(U)F verification certificate from the Russian authority GAN and the release for manufacturing as a storage cask by the Lithuanian Authority VATESI. Following the successful hot trials, the final storage license from VATESI is expected in the near future. The type B(U)F licensing in the Czech Republic will be finished in 2001.

CASTOR® BR3: Design of a Transport and Storage Cask for Spent Fuel From a Belgian Nuclear Power Plant

2001 ◽  
Author(s):  
Ulrich Knopp
Keyword(s):  
Nuclear Power ◽  
Storage Period ◽  
Nuclear Research ◽  
Ductile Cast Iron ◽  
Radioactive Material ◽  
Research Centre ◽  
Spent Fuel ◽  
Interim Storage ◽  
And Storage

Abstract The CASTOR® BR3 cask has been designed and manufactured to accomodate irradiated fuel (U and MOX) from the BR3 test reactor at the nuclear research centre SCK/CEN in Dessel near Mol, Belgium, which is currently being dismantled. The CASTOR® BR3 is designed as a Type B(U)F package for transport and will be licensed in Belgium. In addition, the CASTOR® BR3 needs a license as a storage cask to be operated in an interim cask storage facility. To obtain these licenses, the cask design has to observe the international regulations for the safe transport of radioactive material as well as the special requirements for the cask storage. The CASTOR® BR3 is a member of the CASTOR® family of spent fuel casks, delivered by the German company GNB. In this way, the cask has such typical features as the following: • monolithic cask body made of ductile cast iron; • double-lid system consisting of primary and secondary lid for long-term interim storage of the fuel. This family of casks has been used for over 20 years for transport and storage of spent fuel. In this paper, the IAEA regulatory requirements for transport casks are summarized and it is shown by selected examples how these requirements have been converted into the cask design and the analyses performed for the cask. Finally, the cask features for an interim storage period of up to 50 years will be spotlighted. Main topics are the evaluation of the long term behaviour of selected cask components and the cask monitoring system for the surveillance of the leak tightness of the cask during the storage period.

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 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
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Power Production ◽  
Point Of View ◽  
Mixed Integer ◽  
Disposal Facility ◽  
Time Period ◽  
Interim Storage ◽  
Nuclear Power Production

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.

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.

Operational Experience of TN 24 Dual Purpose Spent Fuel Storage Casks at the DOEL Nuclear Power Plants in Belgium

2001 ◽  
Author(s):  
C. Baroux ◽  
M. Detrilleaux ◽  
G. Demazy
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
High Capacity ◽  
Radiation Shielding ◽  
Ring Closure ◽  
Operational Experience ◽  
Spent Fuel ◽  
Dual Purpose ◽  
New Members

Abstract Spent nuclear fuel has been stored at the DOEL power station in Belgium in dual-purpose metal casks since 1995. The casks were procured from TRANSNUCLEAIRE by SYNATOM to meet the operational demands for on-site dry storage solutions for fuel arising from the four PWR reactors at DOEL. The TN 24 type of cask was chosen and a range of different cask types were developed. The initial requirement was for dual purpose cask to contain fuel from the DOEL units 3 and 4, these having similar fuel types but different lengths, and thus two new members of the TN 24 family were developed; the TN 24 D and TN 24 XL with capacities of 28 and 24 SFA’s. These casks were licensed as B(U) fissile packagings with approval certificates granted by the French and validated by the Belgium competent authorities for the transport configurations. Both cask designs were also analyzed by TRANSNUCLEAIRE in their storage configurations to ensure that the criteria for safe interim storage could be met. Since 1995, a total of 18 TN 24 D and TN 24 XL casks have been loaded with spent fuel assemblies with an average burn-up of 40,000 MWd/tU. SYNATOM subsequently decided to purchase further casks for DOEL 3 and 4 fuels with higher enrichments, higher burn-ups and shorter cooling times. TRANSNUCLEAIRE developed the TN 24 DH and TN 24 XLH casks within the similar envelope size and weight limits. The increase in performance was achieved by an in-depth optimization of each design in terms of radiation shielding, heat transfer and criticality safety. This paper shows how this optimization process was undertaken for the TN 24 DH and TN 24 XLH casks, 16 of which have been ordered by SYNATOM. DOEL 1 and 2 units use much shorter PWR fuel and it was decided to ship the fuel to unit 3 with an internal transfer cask because the handling limitations in the DOEL 1 and 2 pool prohibited the loading of a high capacity dual purpose transport/storage cask. The TN 24 SH cask was subsequently designed for DOEL 1 and 2 PWR fuel with a capacity of 37 assemblies and nine of there casks have been ordered by SYNATOM. The casks are fitted with monitoring devices to detect any change in the performance of the double metal O ring closure system and none of the casks has shown any deterioration in leaktightness. This paper examines the operation experience of loading and storing more than 30 TN 24 dual purpose casks and compares the performance with design expectations.

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