Progress toward decommissioning:Work related to circulation cooling and accumulated water treatment line

Immediate targets

Stably continue reactor cooling and accumulated water treatment, and improve reliability

The cold shutdown condition will be maintained by cooling the reactor by water injection and measures to complement status monitoring will continue to be implemented.

To tackle the increase in accumulated water due to groundwater inflow, fundamental measures to prevent such inflow into the Reactor Buildings will be implemented, while improving the decontamination capability of water-treatment facilities and preparing facilities to control the contaminated water.


Status of Progress Points

(1) Improved reliability of circulating injection cooling

(2) Improved reliability of accumulated water treatment facility

(3) Multifaceted response to accumulated water


Work to improve the reliability of the circulation water injection cooling system and pipes to transfer accumulated water.

  ※ The entire length of contaminated water transfer pipes is approx. 2.1km, including the transfer line of surplus water to the upper heights (approx. 1.3km).


Preventing groundwater from flowing into the Reactor Buildings

Reducing groundwater inflow by pumping sub-drain water


Via a groundwater bypass, reduce the groundwater level around the Building and groundwater inflow into the Building


Installing land-side impermeable walls around Units 1-4 to prevent the inflow of groundwater into R/B


Basic Policy for Treatment of Accumulated Water


Future Challenges and Direction of Responses


Continuation of Measures to Prevent Leakage to External Environment