- Email: [email protected]
Scope of modification of the TRINITI site fuel cycle complex for the IGNITOR project tasks: System of isotopes storage
Fusion Engineering and Design 146 (2019) 924–927
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Scope of modification of the TRINITI site fuel cycle complex for the IGNITOR project tasks: System of isotopes storage
T
⁎
Mikhail Borisovich Rozenkevicha, , A.N. Perevezentseva, M.L. Subbotinb, A.A. Gostevc a
D. Mendeleev University of Chemical Technology of Russia, Moscow, Russia National Research Centre “Kurchatov Institute”, Moscow, Russia c JSC “SSC RF TRINITI”, Moscow, Russia b
A R T I C LE I N FO
A B S T R A C T
Key words: Tokamak IGNITOR Tritium complex TSP TRINITI Fuel cycle
The IGNITOR tokamak project is one of main directions of scientific collaboration between Russia and Italy. The project is entering the stage of technical design for the location of the machine at the TRINITI site in Troitsk of the Moscow region. The IGNITOR machine differs considerably from other machines based on the tokamak concept by using a super strong magnetic field (13 T) and plasma current (11 MA). It will operate with short pulses (of approximately 10 s in length) and will not have a tritium breeding blanket. The requirements of the tritium fuel cycle are high because three tritium pulses per day are foreseen with a total amount of approximately 10 g to be processed daily. Fuelling will be based on gas injection. It necessary to provide a full tritium processing cycle including the storage and supply of the tritium, plasma exhaust purification, separation of the hydrogen isotopes, detritiation of gaseous and water streams, and tritium recovery from the plasma facing components. This paper considers tritium storage and delivery system as part of the fuel cycle.
1. Introduction The purpose of Russia-Italy project IGNITOR is development of tokamak with quasi steady state and super strong magnetic field (up to 13 T). In this field high current (up to 12 MA) will heat high density deuterium-tritium plasma to temperature up to 100–120 MK, which is needed to initiate thermonuclear fusion reaction. Italian scientists have been working on IGNITOR project since 1977. About 100 papers have been published on different aspects of the project [1–5]. Those publications demonstrate high requirements to the power supply and engineering infrastructure of the site and to the tritium fuel cycle of IGNITOR. Operation scenario is based on 10 s pulses. Amount of tritium to be injected to the vacuum vessel is about 0.12 g per pulse. Amount of tritium needed for tokamak operation is about 10 g per day. The tritium fuel cycle has to provide comprehensive service for closed loop of tritium reprocessing, including tritium storage and supply, purification of plasma exhaust, separation of hydrogen isotopes, detritiation of gaseous and liquid streams. The fuel cycle has also to support tritium removal from plasma facing components of the vacuum vessel. According to the inter-government agreement in 2016 [6] Italy is responsible for design, manufacturing and delivery of the tokamak to Russia. The reactor will be located on site of the JSC “SSC RF TRINITI” in Troits of the Moscow region. That site was used about 30 years ago
⁎
for testing of the Russian tokamak TSP [7] with strong toroidal magnetic field. The review [8] showed that the TRINITI site corresponds to the requirements for tokamak IGNITOR. One of the main tasks to enable execution of the IGNITOR experimental program is development of the tritium fuel cycle for safe operation with tritium plasm Main design features proposed in [9] for the tritium cycle for IGNITOR have been further developed in [10]. This paper is devoted to detailed consideration of tritium storage and delivery as one of main sub-system of the fuel cycle. 2. Gas storage system The deuterium and tritium gas storage system (GSS) for the tokamak IGNITOR, considered in [9], as well as in the TSP facility, provides two containers with a uranium getter: one for the storage of tritium, and the other for the storage of a deuterium–tritium mixture. Each container contains approximately 0.5 kg of uranium capable of absorbing up to 60 L of hydrogen. It is envisaged that the sorption of hydrogen will occur at a temperature of approximately 20 °C, and its desorption will occur at 400 °C. The isotope storage system must be able to receive gas and supply it to the tokamak. As an example, Fig. 1 shows a block diagram of the storage unit for deuterium and tritium, as realized on JET [11].
Corresponding author. E-mail address: [email protected] (M.B. Rozenkevich).
https://doi.org/10.1016/j.fusengdes.2019.01.115 Received 5 October 2018; Received in revised form 12 December 2018; Accepted 23 January 2019 Available online 10 February 2019 0920-3796/ © 2019 Elsevier B.V. All rights reserved.
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
Fig. 1. Block diagram of deuterium and tritium, and feeding system of JET based on uranium containers: UC, uranium container; GC, container with a getter of hydrogen; T, calibrated capacity; RFS, feeding system; ISS, system isotope separation; SDG, a system of gas detritiation.
the containers, or circulate it through the containers for chemical cleaning. Tritium and deuterium from the isotope separation system (ISS), or from an external source are fed the appropriate parts of the gas storage system. Each part allows for the use of one container for the feeding of the isotopes, and another container for the receiving of the isotopes . In the presence of helium in hydrogen, this non-adsorbable gas accumulates in the container, which leads to a slowdown in the supply of hydrogen to the hydride, and a decrease in the charging speed of the container. The blocking effect of helium can be eliminated with the circulation of gas through the container. However, such circulation requires the simultaneous use of the inlet and outlet manifolds, and is therefore not possible using one of the containers during hydrogenfeeding mode. After removal of tritium from helium by gas circulation through the container, the helium can be compressed in a special container at the outlet of the vacuum system, and then sent to a chemical purification system for final detritiation prior to release into the atmosphere. The hydride container working toward the feeding of hydrogen must be heated to the decomposition temperature of the hydride at a given pressure. After the end of the operation in this mode, the container will be able to start taking hydrogen only after it has cooled to a temperature at which the equilibrium sorption pressure becomes lower than the hydrogen pressure in the gas feeding system. For a vacuuminsulated container with a hydride-forming material, the cooling process will be extremely long. Therefore, in the ISS of a fusion reactor, the transfer of a hydride container from hydrogen-feeding mode to hydrogen receiving mode requires forced cooling of the hydride-forming material. The scale of the time required to cool the hydride container by a gas flow is illustrated in Fig. 2, which shows the kinetics of cooling a container containing 1 kg of uranium, using flow of faseous nitrogen, from a hydrogen desorption temperature of 400 °C to a temperature of about 30 °C, when the container can be transferred to hydrogen sorption mode (with an equilibrium pressure of hydride formation of 10−4 Pa) [12]. As can be seen from the figure, it takes about 4 h to cool the container. During this time, the container cannot be used for pumping hydrogen from the plasma chamber.
Fig. 2. Kinetics of cooling a hydrid container containing 1 kg of uranium.
Fig. 3. The hydrogen pressure (▲) in a 0.1-m3 tank pumped out by a uranium container holding 1 kg of uranium, and the temperature change (●) of uranium in the container.
Each part of this system includes four uranium containers, one tank, and inlet and outlet manifolds. The tank is used as a container for hydrogen desorption from the container, and determination of its quantity based on a volumetric method. Both parts of the tritium and deuterium storage unit are connected to the pumping system, and can be interconnected. The pumping system makes it possible to remove gas from 925
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
Fig. 4. Block diagram of the deuterium and tritium storage and feeding system of the fusion reactor based on pressure vessel technology: T1-T3, vessels for storage of tritium, deuterium, and their mixtures; T, calibrated capacity; PR, pressure regulator; PF, palladium filter; RFS, reactor feeding system; ISS, isotope separation system; HCPS, hydrogen chemical purification system.
The fulfilment of these requirements at the stage of the fuel cycle development leads to an increase in the number of hydride containers, a complication of the system’s technological scheme, an increase in the number of input and output collectors, and ultimately, a decrease in radiation safety. A tritium storage system in the form of compressed gas is much simpler than a system based on hydride containers. Thus, the storage 10 g of tritium the tokamak IGNITOR will only require a single vessel of 10 L at gas pressure of 0.4 MPa. The design of the devices and the technology required for operation using gases under pressure, including hydrogen, are currently being developed to a very high degree of reliability. For comparison, Fig. 4 shows a block diagram of the storage and supply of tritium, based on the pressure vessel technology. The tritium and deuterium storage and supply system based on pressure vessel technology should include the following:
Considering the use of hydride containers for the reverse process, namely, pumping the plasma chamber of the tokamak, it is necessary to pay attention to the fact that even for materials with a low equilibrium pressure and high rate of formation of hydride, which includes uranium, the exothermicity of the reaction of the hydride formation significantly reduces the efficiency of the containers used for hydrogen pumping. Fig. 3 shows the change in hydrogen pressure in a 0.1-m3 tank pumped using a uranium hydride container holding 1 kg of uranium [13]. Rapid pumping of the hydrogen takes place within a quarter of an hour. At the same time, the temperature of the hydrid material increases by 70 °C, that is, by about 17 °C for each mole of absorbed hydrogen. The rate at which the remaining hydrogen is pumped is determined by the rate at which the heat is removed from the hydrid layer. The absolute value of the temperature increase of the container is shown in Fig. 3, which depends on the mass ratio of the hydride material to the mass of the structural material. In determining the required quantity of the hydrid containers and the configuration of the fusion reactor fuel cycle, a set of requirements should be taken into account:
- Three or more pressure vessels should be used. The capacity of each vessel shall not be less than half of the maximum quantity allowed for the isotope storage and reactor feeding system. - A system consisting of a vacuum pump and a gas compressor/ It should be used for the rapid pumping of tritium from the tanks and pipelines, and its subsequent compression in one of the vessels. - Five or more gas collectors should be available. - A system consisting of a vacuum pump and a gas compressor fot transfer of tritium from one vessel to another/ - A palladium filter and a gas circulation pump for tritium purification from helium-3 should be used.
- The capacity of the ISS sufficient for feeding of the fusion reactor during the pulse discharge should be ensured. - The necessary rate for the receiving of hydrogen isotopes in the feeding system of the fusion reactor should be provided. - The amount of tritium released from the container during leakage loss during an emergency should not exceed a predetermined limit. - Maintenance or replacement of the containers without stopping the operation of the fusion reactor should be provided. - During on-line mode, it should be possible to quickly measure the tritium amount in the container. - In general, the storage and delivery system of tritium based on the use of uranium containers must include the following: - The required number of containers must be met. - The volume capacity for each container must be calibrated. This capacity is necessary to ensure that the container is filled with tritium such that the amount of tritium in the container does not exceed the safety limit, even if the container is able to absorb the amount of tritium above this limit. - A system consisting of a vacuum pump and a gas compressor to be used for the rapid pumping of tritium from the tanks and pipelines, and its subsequent compression in a container. - A sufficient number of gas collectors available, ensuring the operation of the system under all possible modes of operation. - There must be sufficient capacity allowing the cleaning of tritium in the container from helium-3, and measuring the amount of tritium using the volumetric method. - A gas circulation pump for purification of tritium from helium-3.
The system shown in Fig. 4, allows carrying out the same procedures as the system shown in Fig. 1. In a system based on pressure vessel technology, the amount of tritium in the vessels can be measured continuously with a high degree of accuracy (at 0.25% or lower of the whole range of the pressure sensor) by measuring the pressure, gas temperature, and tritium concentration.
3. Conclusion A comparison of the block diagrams of the systems clearly shows the simplicity of the isotope storage system and feeding to the fusion reactor, based on pressure vessel technology, in comparison with a system based on hydride containers. Therefore, this system was applied based on the concept of a fuel cycle for the tokamak IGNITOR [9].
Acknowledgment Work is performed at the expense of means of a subsidy of the Ministry of Education and Science of the Russian Federation No. 14.599.21.0001 of 29.08.2017.
In addition, each uranium container must be equipped with a temperature and pressure control. 926
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
References
and Controlled Nuclear Fusion Research 1 (1988) 239–245 12-19 October,. [8] M. Subbotin, E. Azizov, K. Ramazanov, System analysis of the requirements to the IGNITOR tokamak site location, Symposium of Fusion Technology (2014) P3-018 San Sebastian, Spain, September 29 – October 03,. [9] C. Rizzello, S. Tosti, Overview of the tritium system of Ignitor, Fusion Eng. Des. 83 (2008) 594–600. [10] M. Rozenkevich, A. Perevezentsev, M. Subbotin, Concept of tritium processing and confinement in fuel cycle of ignitor, 26th IAEA Fusion Energy Conference (2016) Kyoto, Japan, Paper No. FIP/P7-16\. [11] A.N. Perevezentsev, et al., Safety aspects of tritium storage in metal hydride form, Fusion Technol. 28 (1995) 1404–1409. [12] A. Perevezentsev, J. Hemmerich, Tritium accounting by in-situ calorimetry of the JET Uranium Container, Fusion Sci. Technol. 41 (2002) 797–800. [13] S. Beloglazov, et al., Performance of a full- scale ITER metal hydride storage bed in comparison with requirements, Fusion Sci. Technol. 54 (2008) 22–26.
[1] B. Coppi, M. Nassi, L.E. Sugiyama, Physics basis for compact ignition experiments, Phys. Scr. 45 (2) (1992) 112. [2] B. Coppi, et al., Optimal regimes for ignition and the Ignitor experiment, Nucl. Fusion 41 (2001) 1253–1257. [3] B. Coppi, et al., Engineering evolution of the ignitor machine, J. Fusion Eng. Des. 58-59 (2001) 815–820. [4] B. Coppi, et al., New developments, plasma physics regimes and issues for the Ignitor experiment, Nucl. Eng. 53 (2013) 104013. [5] B. Coppi, et al., Perspective for the high field approach in fusion research and advances within the Ignitor Program, Nucl. Eng. 55 (2015) 053011(11pp). [6] V. Cherkovets, The Other European Tokamak Collaboration, p.40, February Nuclear Engineering International, 2011, www.neimagazine.com. [7] E.A. Azizov, V.A. Chuyanov, et al., Tokamak with strong magnetic field and adiabatic plasma compression, 12th IAEA International Conference on Plasma Physics
927
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Scope of modification of the TRINITI site fuel cycle complex for the IGNITOR project tasks: System of isotopes storage
T
⁎
Mikhail Borisovich Rozenkevicha, , A.N. Perevezentseva, M.L. Subbotinb, A.A. Gostevc a
D. Mendeleev University of Chemical Technology of Russia, Moscow, Russia National Research Centre “Kurchatov Institute”, Moscow, Russia c JSC “SSC RF TRINITI”, Moscow, Russia b
A R T I C LE I N FO
A B S T R A C T
Key words: Tokamak IGNITOR Tritium complex TSP TRINITI Fuel cycle
The IGNITOR tokamak project is one of main directions of scientific collaboration between Russia and Italy. The project is entering the stage of technical design for the location of the machine at the TRINITI site in Troitsk of the Moscow region. The IGNITOR machine differs considerably from other machines based on the tokamak concept by using a super strong magnetic field (13 T) and plasma current (11 MA). It will operate with short pulses (of approximately 10 s in length) and will not have a tritium breeding blanket. The requirements of the tritium fuel cycle are high because three tritium pulses per day are foreseen with a total amount of approximately 10 g to be processed daily. Fuelling will be based on gas injection. It necessary to provide a full tritium processing cycle including the storage and supply of the tritium, plasma exhaust purification, separation of the hydrogen isotopes, detritiation of gaseous and water streams, and tritium recovery from the plasma facing components. This paper considers tritium storage and delivery system as part of the fuel cycle.
1. Introduction The purpose of Russia-Italy project IGNITOR is development of tokamak with quasi steady state and super strong magnetic field (up to 13 T). In this field high current (up to 12 MA) will heat high density deuterium-tritium plasma to temperature up to 100–120 MK, which is needed to initiate thermonuclear fusion reaction. Italian scientists have been working on IGNITOR project since 1977. About 100 papers have been published on different aspects of the project [1–5]. Those publications demonstrate high requirements to the power supply and engineering infrastructure of the site and to the tritium fuel cycle of IGNITOR. Operation scenario is based on 10 s pulses. Amount of tritium to be injected to the vacuum vessel is about 0.12 g per pulse. Amount of tritium needed for tokamak operation is about 10 g per day. The tritium fuel cycle has to provide comprehensive service for closed loop of tritium reprocessing, including tritium storage and supply, purification of plasma exhaust, separation of hydrogen isotopes, detritiation of gaseous and liquid streams. The fuel cycle has also to support tritium removal from plasma facing components of the vacuum vessel. According to the inter-government agreement in 2016 [6] Italy is responsible for design, manufacturing and delivery of the tokamak to Russia. The reactor will be located on site of the JSC “SSC RF TRINITI” in Troits of the Moscow region. That site was used about 30 years ago
⁎
for testing of the Russian tokamak TSP [7] with strong toroidal magnetic field. The review [8] showed that the TRINITI site corresponds to the requirements for tokamak IGNITOR. One of the main tasks to enable execution of the IGNITOR experimental program is development of the tritium fuel cycle for safe operation with tritium plasm Main design features proposed in [9] for the tritium cycle for IGNITOR have been further developed in [10]. This paper is devoted to detailed consideration of tritium storage and delivery as one of main sub-system of the fuel cycle. 2. Gas storage system The deuterium and tritium gas storage system (GSS) for the tokamak IGNITOR, considered in [9], as well as in the TSP facility, provides two containers with a uranium getter: one for the storage of tritium, and the other for the storage of a deuterium–tritium mixture. Each container contains approximately 0.5 kg of uranium capable of absorbing up to 60 L of hydrogen. It is envisaged that the sorption of hydrogen will occur at a temperature of approximately 20 °C, and its desorption will occur at 400 °C. The isotope storage system must be able to receive gas and supply it to the tokamak. As an example, Fig. 1 shows a block diagram of the storage unit for deuterium and tritium, as realized on JET [11].
Corresponding author. E-mail address: [email protected] (M.B. Rozenkevich).
https://doi.org/10.1016/j.fusengdes.2019.01.115 Received 5 October 2018; Received in revised form 12 December 2018; Accepted 23 January 2019 Available online 10 February 2019 0920-3796/ © 2019 Elsevier B.V. All rights reserved.
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
Fig. 1. Block diagram of deuterium and tritium, and feeding system of JET based on uranium containers: UC, uranium container; GC, container with a getter of hydrogen; T, calibrated capacity; RFS, feeding system; ISS, system isotope separation; SDG, a system of gas detritiation.
the containers, or circulate it through the containers for chemical cleaning. Tritium and deuterium from the isotope separation system (ISS), or from an external source are fed the appropriate parts of the gas storage system. Each part allows for the use of one container for the feeding of the isotopes, and another container for the receiving of the isotopes . In the presence of helium in hydrogen, this non-adsorbable gas accumulates in the container, which leads to a slowdown in the supply of hydrogen to the hydride, and a decrease in the charging speed of the container. The blocking effect of helium can be eliminated with the circulation of gas through the container. However, such circulation requires the simultaneous use of the inlet and outlet manifolds, and is therefore not possible using one of the containers during hydrogenfeeding mode. After removal of tritium from helium by gas circulation through the container, the helium can be compressed in a special container at the outlet of the vacuum system, and then sent to a chemical purification system for final detritiation prior to release into the atmosphere. The hydride container working toward the feeding of hydrogen must be heated to the decomposition temperature of the hydride at a given pressure. After the end of the operation in this mode, the container will be able to start taking hydrogen only after it has cooled to a temperature at which the equilibrium sorption pressure becomes lower than the hydrogen pressure in the gas feeding system. For a vacuuminsulated container with a hydride-forming material, the cooling process will be extremely long. Therefore, in the ISS of a fusion reactor, the transfer of a hydride container from hydrogen-feeding mode to hydrogen receiving mode requires forced cooling of the hydride-forming material. The scale of the time required to cool the hydride container by a gas flow is illustrated in Fig. 2, which shows the kinetics of cooling a container containing 1 kg of uranium, using flow of faseous nitrogen, from a hydrogen desorption temperature of 400 °C to a temperature of about 30 °C, when the container can be transferred to hydrogen sorption mode (with an equilibrium pressure of hydride formation of 10−4 Pa) [12]. As can be seen from the figure, it takes about 4 h to cool the container. During this time, the container cannot be used for pumping hydrogen from the plasma chamber.
Fig. 2. Kinetics of cooling a hydrid container containing 1 kg of uranium.
Fig. 3. The hydrogen pressure (▲) in a 0.1-m3 tank pumped out by a uranium container holding 1 kg of uranium, and the temperature change (●) of uranium in the container.
Each part of this system includes four uranium containers, one tank, and inlet and outlet manifolds. The tank is used as a container for hydrogen desorption from the container, and determination of its quantity based on a volumetric method. Both parts of the tritium and deuterium storage unit are connected to the pumping system, and can be interconnected. The pumping system makes it possible to remove gas from 925
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
Fig. 4. Block diagram of the deuterium and tritium storage and feeding system of the fusion reactor based on pressure vessel technology: T1-T3, vessels for storage of tritium, deuterium, and their mixtures; T, calibrated capacity; PR, pressure regulator; PF, palladium filter; RFS, reactor feeding system; ISS, isotope separation system; HCPS, hydrogen chemical purification system.
The fulfilment of these requirements at the stage of the fuel cycle development leads to an increase in the number of hydride containers, a complication of the system’s technological scheme, an increase in the number of input and output collectors, and ultimately, a decrease in radiation safety. A tritium storage system in the form of compressed gas is much simpler than a system based on hydride containers. Thus, the storage 10 g of tritium the tokamak IGNITOR will only require a single vessel of 10 L at gas pressure of 0.4 MPa. The design of the devices and the technology required for operation using gases under pressure, including hydrogen, are currently being developed to a very high degree of reliability. For comparison, Fig. 4 shows a block diagram of the storage and supply of tritium, based on the pressure vessel technology. The tritium and deuterium storage and supply system based on pressure vessel technology should include the following:
Considering the use of hydride containers for the reverse process, namely, pumping the plasma chamber of the tokamak, it is necessary to pay attention to the fact that even for materials with a low equilibrium pressure and high rate of formation of hydride, which includes uranium, the exothermicity of the reaction of the hydride formation significantly reduces the efficiency of the containers used for hydrogen pumping. Fig. 3 shows the change in hydrogen pressure in a 0.1-m3 tank pumped using a uranium hydride container holding 1 kg of uranium [13]. Rapid pumping of the hydrogen takes place within a quarter of an hour. At the same time, the temperature of the hydrid material increases by 70 °C, that is, by about 17 °C for each mole of absorbed hydrogen. The rate at which the remaining hydrogen is pumped is determined by the rate at which the heat is removed from the hydrid layer. The absolute value of the temperature increase of the container is shown in Fig. 3, which depends on the mass ratio of the hydride material to the mass of the structural material. In determining the required quantity of the hydrid containers and the configuration of the fusion reactor fuel cycle, a set of requirements should be taken into account:
- Three or more pressure vessels should be used. The capacity of each vessel shall not be less than half of the maximum quantity allowed for the isotope storage and reactor feeding system. - A system consisting of a vacuum pump and a gas compressor/ It should be used for the rapid pumping of tritium from the tanks and pipelines, and its subsequent compression in one of the vessels. - Five or more gas collectors should be available. - A system consisting of a vacuum pump and a gas compressor fot transfer of tritium from one vessel to another/ - A palladium filter and a gas circulation pump for tritium purification from helium-3 should be used.
- The capacity of the ISS sufficient for feeding of the fusion reactor during the pulse discharge should be ensured. - The necessary rate for the receiving of hydrogen isotopes in the feeding system of the fusion reactor should be provided. - The amount of tritium released from the container during leakage loss during an emergency should not exceed a predetermined limit. - Maintenance or replacement of the containers without stopping the operation of the fusion reactor should be provided. - During on-line mode, it should be possible to quickly measure the tritium amount in the container. - In general, the storage and delivery system of tritium based on the use of uranium containers must include the following: - The required number of containers must be met. - The volume capacity for each container must be calibrated. This capacity is necessary to ensure that the container is filled with tritium such that the amount of tritium in the container does not exceed the safety limit, even if the container is able to absorb the amount of tritium above this limit. - A system consisting of a vacuum pump and a gas compressor to be used for the rapid pumping of tritium from the tanks and pipelines, and its subsequent compression in a container. - A sufficient number of gas collectors available, ensuring the operation of the system under all possible modes of operation. - There must be sufficient capacity allowing the cleaning of tritium in the container from helium-3, and measuring the amount of tritium using the volumetric method. - A gas circulation pump for purification of tritium from helium-3.
The system shown in Fig. 4, allows carrying out the same procedures as the system shown in Fig. 1. In a system based on pressure vessel technology, the amount of tritium in the vessels can be measured continuously with a high degree of accuracy (at 0.25% or lower of the whole range of the pressure sensor) by measuring the pressure, gas temperature, and tritium concentration.
3. Conclusion A comparison of the block diagrams of the systems clearly shows the simplicity of the isotope storage system and feeding to the fusion reactor, based on pressure vessel technology, in comparison with a system based on hydride containers. Therefore, this system was applied based on the concept of a fuel cycle for the tokamak IGNITOR [9].
Acknowledgment Work is performed at the expense of means of a subsidy of the Ministry of Education and Science of the Russian Federation No. 14.599.21.0001 of 29.08.2017.
In addition, each uranium container must be equipped with a temperature and pressure control. 926
Fusion Engineering and Design 146 (2019) 924–927
M.B. Rozenkevich et al.
References
and Controlled Nuclear Fusion Research 1 (1988) 239–245 12-19 October,. [8] M. Subbotin, E. Azizov, K. Ramazanov, System analysis of the requirements to the IGNITOR tokamak site location, Symposium of Fusion Technology (2014) P3-018 San Sebastian, Spain, September 29 – October 03,. [9] C. Rizzello, S. Tosti, Overview of the tritium system of Ignitor, Fusion Eng. Des. 83 (2008) 594–600. [10] M. Rozenkevich, A. Perevezentsev, M. Subbotin, Concept of tritium processing and confinement in fuel cycle of ignitor, 26th IAEA Fusion Energy Conference (2016) Kyoto, Japan, Paper No. FIP/P7-16\. [11] A.N. Perevezentsev, et al., Safety aspects of tritium storage in metal hydride form, Fusion Technol. 28 (1995) 1404–1409. [12] A. Perevezentsev, J. Hemmerich, Tritium accounting by in-situ calorimetry of the JET Uranium Container, Fusion Sci. Technol. 41 (2002) 797–800. [13] S. Beloglazov, et al., Performance of a full- scale ITER metal hydride storage bed in comparison with requirements, Fusion Sci. Technol. 54 (2008) 22–26.
[1] B. Coppi, M. Nassi, L.E. Sugiyama, Physics basis for compact ignition experiments, Phys. Scr. 45 (2) (1992) 112. [2] B. Coppi, et al., Optimal regimes for ignition and the Ignitor experiment, Nucl. Fusion 41 (2001) 1253–1257. [3] B. Coppi, et al., Engineering evolution of the ignitor machine, J. Fusion Eng. Des. 58-59 (2001) 815–820. [4] B. Coppi, et al., New developments, plasma physics regimes and issues for the Ignitor experiment, Nucl. Eng. 53 (2013) 104013. [5] B. Coppi, et al., Perspective for the high field approach in fusion research and advances within the Ignitor Program, Nucl. Eng. 55 (2015) 053011(11pp). [6] V. Cherkovets, The Other European Tokamak Collaboration, p.40, February Nuclear Engineering International, 2011, www.neimagazine.com. [7] E.A. Azizov, V.A. Chuyanov, et al., Tokamak with strong magnetic field and adiabatic plasma compression, 12th IAEA International Conference on Plasma Physics
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