A catalytic isotope exchange facility for water detritiation is operated at the Tritium Laboratory Karlsruhe (TLK) in order to investigate the simultaneous transfer of tritium and deuterium between ...various molecular hydrogen isotopes and deuteriated/tritiated water. Four catalyst-packing combinations from different manufacturers (SCK-CEN Belgium, Mendeleev University Russia, Institute of Cryogenics and Isotopic Technologies (ICIT) Romania-TLK, Showa Eng. Japan) are currently being tested. Experiments have been performed to determine the height equivalent of theoretical plate (HETP) and the mass transfer coefficients during deuterium, tritium or simultaneous deuterium and tritium exchange between deuteriated and tritiated water and gaseous hydrogen isotopes. In the simultaneously tritium and deuterium transfer experiments, both the transfer of tritium and deuterium from liquid to gas and the transfer of tritium from liquid to gas and deuterium in the opposite direction from gas to liquid was investigated.
The behavior of NAFION membrane was analyzed in presence of high activity tritiated water. The fundamental radiolytical processes have been analyzed by simulation, using quantum mechanical methods. ...NAFION and PTFE samples were immersed in water and exposed to gamma radiation fields. The samples were characterized by FTIR spectrometry and fluoride emissions. Self radiolytical processes were analyzed by storage of NAFION in high activity triatiated water. The induced modification analyses were carried out using FTIR and fluoride emissions characterization. The experimental results were correlated with quantum-chemical simulations.
Hydrogen isotopes from the Water Detritiation System (WDS) developed at the Tritium Laboratory Karlsruhe (TLK) are fed to a cryogenic distillation (CD) column. In order to purify this gas a permeator ...of 1
m
2 membrane area was found to be necessary. Technical requirements, regulations of the European Union and the TLK safety philosophy demanded that the component had to be designed and manufactured in accordance to the “Technical Terms of Delivery and Acceptance” for tritium primary systems in the Tritium Laboratory Karlsruhe and in conformity to the European Pressure Equipment Directive (PED). Since there was no response to the call for tender from industrial partners, the permeator was manufactured at the main workshop of the Forschungszentrum Karlsruhe (FZK). Acceptance tests and commissioning showed that the component performance is better than design requirements. This paper describes the construction and commissioning of the permeator and gives the results of the commissioning tests.
One of the most used methods for tritium recovery from different sources of tritiated water is based on the combination between Combined Electrolysis Catalytic Exchange (CECE) and Cryogenic ...Distillation (CD) processes. The development, i.e. configuration, design and performance testing of critical components, of a tritium recovery system based on the combination CECE-CD is essential for both JET and ITER. For JET, a Water Detritiation System (WDS) is not only needed to process tritiated water which has already been accumulated from operation, but also for the tritiated water which will be generated during decommissioning. For ITER, the WDS is one of the key systems to control the tritium content in the effluents streams, to recover as much tritium as possible and consequently to minimize the impact on the environment. A cryogenic distillation facility with the aim to investigate the trade-off between CECE-CD, to validate different components and mathematical modelling software is current under development at Tritium Laboratory Karlsruhe (TLK) as an extension of the existing CECE facility.
During plasma operation of ITER in the DT phase, tritium will be distributed in the different subsystems of the fuel cycle; tritium inventories within the systems are not constant, but vary as the ...gas moves through these systems during the burn and dwell periods. To evaluate the tritium content in each sub-system of the fuel cycle of ITER, a dynamic model for tritium inventory calculation was developed. The code reflects the design of each system in various degrees of detail; both the physical processes characteristics and in some cases the associated control systems are modeled. The amount of tritium needed for ITER operation has a direct impact on the tritium inventories within the fuel cycle subsystems. As ITER will function in pulses, the main characteristics that influence both the maximum value of tritium inventories in the systems and the rapid tritium recovery from the fuel cycle as necessary for refueling are discussed. Eventually the inventories in the Isotope Separation System (as the system with the highest tritium inventory) for short and long pulses and their dependence on the packing molar inventory are presented.
The research for the performance improvement of the liquid phase chemical exchange (LPCE) column has been carried out at Nagoya University with the collaboration of National Institute for Fusion ...Science (NIFS) and Tritium Laboratory Karlsruhe (TLK). Kogel catalysts and Dixon gauze rings were mixed at a certain ratio and packed in the column homogeneously. A stage-wise model, named “Channeling stage model”, was also developed to predict separative performances of the column. In order to design a LPCE column to be tested at the TLK experimental facility, we examined the effect of the catalyst packed ratio and the gas–liquid ratio on the separative performance of the column. The optimal value of the catalyst packed ratio was obtained to 30%. The specifications of the column and the operating conditions of the equipment were reported.
These days more and more modern electrolysis cells are operated with new solid polymer membranes. These membranes prevailing DuPont's Nafion® are not only used for electrolysis but as well for the ...wide spectrum of fuel cells due to their good mechanical and chemical stability and the high proton conductivity. For that reason it is intended to use these solid polymer membranes for the electrolyzer units in the ITER Water Detritiation System (WDS). The influence of Tritium during water electrolysis to the membrane material is still not sufficiently investigated. Therefore long-term experiments of solid polymer membranes were performed at Tritium Laboratory Karlsruhe (TLK). The chemical degradation and durability behavior of the used Nafion® 117 membrane are investigated in details under tritiated water conditions. For comparison a second cell was operated with demineralized water for the same period.
In addition to the experimental rigs with single Nafion® membranes, two industrial electrolyzer units equipped with Nafion® membranes were operated during different tritium experiments at TLK. Before operation they had been modified to be compatible for tritium operation. After long operation period no degradation in the performance of the electrolyzers is observable.
EU fuel cycle development priorities for ITER Murdoch, D.; Cristescu, I.; Day, C. ...
Fusion engineering and design,
10/2007, Volume:
82, Issue:
15
Journal Article, Conference Proceeding
Peer reviewed
Open access
The paper describes the key elements of the EU fuel cycle development for ITER. The programme is now closely focused on the systems allocated to the EU for in-kind supply. These include the isotope ...separation and water detritiation systems (ISS and WDS) and the cryopumps for torus exhaust, neutral beam injectors (NBI) and cryostat pumping. For all of these systems, which must be available for (or even before) first plasma operation, prototypes at ITER-relevant scale are under design and construction and the concepts, critical issues, experimental programmes and status of these development projects are outlined in the paper.
The most suitable process for water detritiation is the combined electrolysis catalytic exchange (CECE) process, a combination of electrolysis and catalytic exchange of hydrogen isotopes in a liquid ...phase catalytic exchange (LPCE) column. Tritium is recovered in gas phase from tritiated water and then injected in the cryogenic distillation system for further enrichment. At the Tritium Laboratory, Karlsruhe (TLK) a CECE facility is running in order to investigate the simultaneous transfer of tritium and deuterium between gas and water. Experiments are performed to determine the height equivalent of theoretical plate (HETP) and the mass transfer coefficients for deuterium and tritium. The purpose of the experiments is to provide the data required for the design of large water detritiation facility for JET and ITER.
