Hee-Seok Kang

Performance of a Depleted Uranium Bed for a Nuclear Fusion Fuel Cycle

Abstract The Tritium Storage & Delivery System (SDS) is part of a tokamak-type nuclear fusion reactor fuel cycle. For the safety of this cycle, the hydrogen isotopes are stored in a metal hydride form in the SDS. Depleted uranium (DU) was chosen as the storage material. DU hydride can be heated to very high temperatures that are sufficient for pumping hydrogen isotopes without using gas pumps. The experimental apparatus used to test the experimental DU bed consists of a tank that stores and measures the hydrogen, and a DU bed used for the hydriding and dehydriding of hydrogen. The DU bed is a vertical double-cylinder type with sintered metal filters. The bed is composed of primary and secondary vessels. The primary vessel contains DU, and a vacuum layer is formed between the primary and secondary vessels. In this study, recent experimental results on the pretreatment (activation and powderization) of DU and the direct hydrogen recovery and delivery of a DU bed are presented. In addition, the relationship between hydrogen pressure and temperature in the DU bed is obtained.

Detritiation Technology Development for Environmental Protection

Abstract Korea is operating 24 nuclear power plants and a highly advanced neutron application reactor HANARO (High-flux Advanced Neutron Application Reactor). In addition, Korea is designing a tritium storage and delivery system (SDS) for ITER. We have been developing detritiation and tritium storage technologies since the operation of Wolsong CANDU (Canada Deuterium-Uranium) station in 1983. The Wolsong Tritium Removal System (TRF) was designed to remove tritium generated in heavy water of the moderator and heat transport. Catalysts transfer tritium from the tritiated heavy water to gaseous tritiated deuterium. The hydrogen isotopes, including tritium, are transported to a cryogenic distillation system where the tritium is removed for safe storage. Conventional high-pressure storage tanks can be dangerous for the storage of radioactive tritium gas. We have been studying various kinds of metal hydride, such as titanium, zirconium cobalt, and depleted uranium. Titanium was proven to store tritium safely and efficiently for a long period of time. Zirconium cobalt, meanwhile, incorporates tritium safely and compactly, and temporarily holds large quantities that can be recovered easily under safe, controlled conditions. However owing to the disproportionation characteristics of zirconium cobalt, we are now developing depleted uranium hydride safe handling technologies. In this technical note, we present the details of the recent development progress of these tritium systems.

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.