Uranium refining and conversion plant (URCP)

The uranium refining and conversion plant (URCP) at Ningyo-toge was constructed in 1981 to demonstrate refining and conversion of yellow cake (or uranium trioxide) to uranium hexafluoride via uranium tetrafluoride. There are two different types of refining processes in the URCP. One is the wet process for converting natural uranium and the other is the dry process for reprocessed uranium.

Dismantling of the dry process facilities began in March 2008. The basic strategy concerning plant dismantling was to optimize the total labour costs and minimize the radioactive wastes generated. The basic schedule for dismantling is as follows.

• Phase 1: removal of large equipment or processes involving uranium hexafluoride,

• Phase 2: removal of the greater part of the utilities connecting the main process of URCP,

• Phase 3: removal of equipment of main process,

• Phase 4: removal of ventilation systems.

The majority of equipment will be dismantled, except for building decon­tamination, by 2013. A large amount of fluidization media had been stored in tanks held underground in the URCP. The fluidization media is com­posed of small aluminum pellets which absorbed uranium oxides or unre­acted uranium tetrafluoride used for the fluorination reaction. They therefore contain high levels of uranium and thorium as progenies of U-232. Among its progenies, Tl-208 is a high gamma emitter, so some external exposure will arise in handling the fluidization media.

Добавить комментарий

Ваш e-mail не будет опубликован. Обязательные поля помечены *