Sung-Paal Yim

Performance of 500kCi Tritium Storage Vessel for WTRF

A prototype TSV (Tritide Storage Vessel) has been manufactured for the long-term storage of tritium of the WTRF (Wolsong Tritium Removal Facility). A performance test was carried out to demonstrate that the TSV could hold a minimum of 500kCi of tritium. This experiment was conducted by a batch type hydriding reaction. Hydrogen gas equivalent to 50kCi of tritium was reacted with the titanium sponge in a batch reaction. Experimental results for 10 batches show that the TSV has enough capacity to store 500kCi of tritium.

KOREA'S ACTIVITIES FOR THE DEVELOPMENT OF A DETRITIATION SYSTEM

Tritiated gas and water should be properly treated to minimize an environmental tritium emission in nuclear fusion research facilities. Tritiated gas is usually treated in two steps: it is first oxidized to a tritiated water vapor by a catalyst and then the vapor is adsorbed in a molecular sieve drier. We have used a 1wt.% Pt/SDBC polymer catalyst and Zeolite 13X for the tritiated gas removal system. We confirmed that the decontamination factor of the equipment was more than 100 under a gas flow rate of 90 liters/hr and at a temperature of 65-80 °C.Furthermore we have developed a tritiated organic liquid treatment process. We have used a 0.5wt.% Pd/Al2O3 catalyst to oxidize an organic liquid. The simulated organic liquid was converted to water by over 99%. We have also developed a small scale CECE (Combined Electrolysis and Chemical Exchange) process by combining an LPCE (Liquid phase Catalytic Exchange) catalytic column with SPE (Solid Polymer Electrolyte) electrolysis. The experimental results of the CECE process produced a decontamination factor of 13-20. We used the electrolyte Nafion 117 which was coated with Pt as a cathode catalyst and IrO2 as an anode catalyst. We also tested a palladium alloy membrane for a purification of the hydrogen in the detritiation process.

Development of a 500 kCi BU-type Transport Container

A BU-type container was developed to protect persons, property and the environment from the effects of radiation during the transport of 500 kCi of tritium. Tritium in the form of T2 is immobilized as a solid with a suitable metal to form a solid metal hydride. The container had a cross-linked polyethylene foam in-between a ceramic insulation layer and a polyurethane foam. A prototype shipping package was fabricated and subjected to several tests involving a 9 m free drop test, a 1 m puncture test and a fire test (800°C, 30 min.) in accordance with the Korean regulations. The tritium containment was assured by a helium leakage test not only for a normal condition but also for accident conditions.

Development of Tritium Technologies at KAERI

Abstract Tritium is formed by neutrons captured from deuterium. If left to accumulate, tritium oxide will become a hazard to the operating staff and public. The primary purpose of a Tritium Removal Facility (TRF) is to reduce tritium concentration in a heavy water moderator. In Korea, operation of a TRF commenced at the Wolsong Nuclear Power Site on July 26th, 2007. Nowadays, KAERI is developing a Very High Temperature Gas Cooled Reactor (VHTR). We have developed a tritium behavior analysis code for the VHTR. We also developed analytical methods for the measurement of food stuffs. Korea shared in the construction of the ITER fuel cycle plant with the EU, Japan, and the US, and is responsible for the supply of an SDS (Tritium Storage and Delivery System). We present the recent progress in the development of tritium storage technology, and safety features of the related system. KAERI has been developing tritium technologies related to the Wolsong TRF, HANARO, VHTR, and nuclear fusion fuel systems. We thus present details on the recent development progress of these tritium systems.

Tritium Research Activities in KAERI

Abstract Korea has twenty nuclear power plants and a nuclear research reactor in operation. Out of the twenty plants, four are CANDU reactors at the Wolsong Nuclear Power Site. In the CANDU reactors, deuterium (heavy water) is used as a moderator and as the primary heat transport from the nuclear fuel. The nuclear research reactor, HANARO, in KAERI (Korea Atomic Energy Research Institute) uses heavy water as a neutron reflector. Tritium is formed by a neutron capture from the deuterium. If left to accumulate, tritium oxide would become a hazard to the operating staff and public. The primary purpose of a Tritium Removal Facility (TRF) is to reduce tritium concentration in a heavy water moderator. Operation of a TRF commenced at the Wolsong Nuclear Power Site on July 26th, 2007. Korea shared in the construction of the ITER fuel cycle plant with the EU, Japan, and US, and is responsible for the supply of an SDS (Tritium Storage and Delivery System). KAERI has been developing tritium technologies related to the Wolsong TRF, HANARO, and nuclear fusion fuel systems. We thus present details on the recent development status of the tritium systems.