Kyu-Min Song

ITER storage and delivery system R&D in Korea

Korea is supposed to develop the ITER tritium storage and delivery system (SDS), which is one of the main components of the ITER tritium plant. For successful procurement, there are several ongoing R&D activities in the detailed design phase. Investigation of design parameters of the storage and delivery beds has been performed. Small and large-scale mock-ups of ZrCo beds are used to test the capability of desirable rapid delivery and recovery performance and to establish the pertinent procedure of in-bed calorimetry. An experimental apparatus is prepared to develop the integration and verification technologies for the unit processes of the tritium SDS. The performance test of a tritium-compatible metal bellows pump is examined, and the results show a reasonable agreement with the catalog data of the pump. A tritium storage and delivery bed simulator has been developed to simulate various bed operation scenarios under normal and abnormal conditions. A prototype of the SDS simulator is fabricated, and the bed operation scenario generation program to be applied to this simulator is developed. The design requirement of the tritium loading station (TLS) calorimeter is prepared based on a benchmarking mock-up calorimeter, namely, Korea Electric Power Research Institute Tritium Laboratory (KEPTL) calorimeter. Documents for the procurement of the TLS calorimeter will be developed through the experience on the KEPTL calorimeter operation.

R&D Activities on the Tritium Storage and Delivery System in Korea

Abstract R&D activities on the tritium storage and delivery system include the development of getter beds to increase tritium recovery and delivery performance, the investigation of tritium reaction characteristics with ZrCo metal-hydride, in-bed calorimetry as tritium measurement techniques, and the development of process design technologies for the storage and delivery system such as pump performance test and bed simulator. The current status of the R&D activities on these subjects is addressed in this paper.

Korea's activities for the development of ITER tritium storage and delivery systems

Abstract The ITER fuel cycle plant is composed of various subsystems such as a long term tritium storage system (LTS), a fuel storage and delivery system (SDS), a tokamak exhaust processing system, a hydrogen isotope separation system, and a tritium plant analytical system. Korea shares in the construction of the ITER fuel cycle plant with the EU, Japan and US, and is responsible for the development and supply of the SDS and LTS. The authors thus present details on the development status of the tritium transport container, the long term tritium storage beds, the short-term delivery system T2, DT, and the D2 storage beds, the calorimetry system, and the associated He-3 recovery loop, the over pressure protection systems, and the gas analysis manifold connected to the tritium plant’s analytical systems.

Key technologies for tritium storage bed development

Abstract ITER Storage and delivery system (SDS) is a complex assembly system. Lots of individual components including tens of storage beds, a few reactors, multiple transfer pumps, vessels, umpteen instruments & sensors which are interconnected with tubing and fittings in a confined glovebox system are to be installed in the given Tritium Plant area. The most important SDS getter bed will be utilized for absorbing and desorbing of hydrogen isotopes in accordance with the fusion fuel cycle scenario. This paper deals with R&D activities on SDS bed design, especially thermal hydraulic analysis in heat loss aspect, the real-time gas analysis in He-3 collection system, and introductory experimental plans using depleted uranium (DU) getter material for storage of hydrogen isotopes, especially of tritium.

Test of a large volume calorimeter in KEPRI tritium laboratory

A tritium assaying and dispensing system has been designed and is being constructed in KEPTL (Korea Electric Power Research Institute, Tritium Laboratory). This facility will be used to supply tritium from WTRF (Wolsong Tritium Removal Facility) to customers for industrial uses, R&D application, ITER operation and other purposes. In order to account the tritium amount loaded in and out this facility, KEPTL purchased a large volume calorimeter from Setaram. This calorimeter is integrated in a dedicated room of the KEPTL in 2008 and the site acceptance tests are completed. The KEPTL calorimeter is a twin cell type and its measuring range is from 0.01 gram of tritium to 60 gram of tritium. The tritium storage beds loaded into the measuring cell of the calorimeter reach a maximum size of 200 mm in diameter and 570 mm in height. The performance test has been successfully completed with a Joule effect cell simulating tritium decay heat. It is demonstrated that the precision of the calorimeter is measured to be less than 0.28% at 50 mW and 0.13% at 10W. Relative error on real tritium test is measured to be 0.06% on 37 TBq of tritium.

ESTIMATION OF THERMOPHYSICAL PROPERTIES IN MASSIVE ZrCoHx SYSTEM

Abstract Thermophysical properties of the complex metal hydride system such as zirconium cobalt hydride, an intermetallic hydride compound, in a massive state were estimated by introducing a crystal lattice structure in a stepwise formation and applying a mixing rule for each property. Experimental data in rarity in metal hydride system was used to calculate and to correlate the consistency of the mixed thermal and physical properties of the complex atomic structure in a unit cell. As a result, the volume expansion of the ZrCoHx was greatly influenced by the hydrogen content and increased to a maximum range of 36% at ZrCoH3 system, but no meaning in the thermal expansion in engineering concept. In consideration of the heat capacity the temperature effect due to the hydrogen—an interstitial heat quantity—in the metal complex formation was mainly attributed, but not much for the hydrogen content (H/ZrCo ratio). In the temperature range between 200K and 600K the heat capacity of hydrogen atom was taken into account to reveal a sharp discrepancy in its non-hydriding property, especially in the lower temperature range. Atomic hydrogen was expected to behave from a gas to a solid property in heat capacity in the temperature ranges from 600K to 200K.

The Prediction of Tritium Level Reduction of Wolsong NPPs by Heavy Water Detritiation with WTRF

The amount of the tritium removed from the Wolsong NPPs after the WTRF operation start was simulated through the modeling of the tritium balance between the Wolsong NPPs and the WTRF. Five WTRF operating scenarios were proposed and the profiles of the tritium level depending on these scenarios were obtained from the simulation. It was predicted that about 9×1017 Bq/yr of tritium would be removed in the beginning of WTRF operation. However the tritium levels in the moderators will be steadily reduced and saturated less than 3×1011 Bq/kg in 2013, and then about 2×1017 Bq/yr of tritium will be removed from the Wolsong NPPs by the WTRF operation.

Development of 100-kCi Tritium Transport Vessel

In this paper, a tritium storage and transport vessel was designed and manufactured to use the tritium of Wolsong TRF for the tritium industry. Uranium and zirconium-cobalt (ZrCo) metals were selected for the tritium storage materials. The transport vessel was designed on the basis of Type-B transportation package standards. The vessel was composed of a steel drum, inner packing materials, and a storage bed. The safety of the transport vessel was evaluated by structural and thermal analyses.

Performance Test of Pump Combination Between Normetex 15 Scroll and MB 601 Pumps

Abstract The tritium compatible pumps are applied to the transportation of the fuel gases in the nuclear fusion power plant. Based on the limitations to handle the tritium gas, the development of the tritium compatible pumps is restricted and the information of those is not well-known. Through Normetex scroll and metal bellows pumps, which are utilized in the tritium facility in the world, are famous tritium compatible pumps, the information has the limitations for the capability of those. It is needed to evaluate the performance of those experimentally. The non-destructive characteristics evaluation system for dry vacuum pump is utilized for the performance tests of the MB 601 HP and the combination of the Normetex 15 scroll and the MB 601 HP pumps. Nitrogen and helium gases are applied for the performance tests. In the case of the MB 601 HP, significant dependency is found on gas species: the test on the pumping speeds with using nitrogen shows the similar result with the catalogue data but the different behavior with using helium gas. In the case of the combination of the Normetex 15 scroll and the MB 601 HP pumps, however, it is observed that the effect of the species of gases is reduced.

PARAMETER ESTIMATIONS FOR THE KINETICS OF DEHYDRIDING REACTION BETWEEN ZIRCONIUM-COBALT AND HYDROGEN

Abstract The dehydriding reaction between ZrCo and hydrogen is the most important role of delivering hydrogen isotopes for fusion energies. Many researchers experimented in various conditions and estimated the relationship between ZrCo and hydrogen. In this study the kinetic approaches are performed using numerical simulations between ZrCo and hydrogen. Two kinds of parameter estimations are performed for the equilibrium pressure and the kinetics modeling and those are validated by the good agreement between predicted and experimental data. Based on the numerical simulation with obtained parameters, more rapid rates of dehydriding reaction can be achieved with lower pressure and higher temperature.