Kyushu plans further safety enhancements at Sendai

18 December 2015

Although units 1 and 2 of the Sendai nuclear power plant in Japan's Kagoshima prefecture have passed new safety standards and are the only reactors in the country so far to have restarted, operator Kyushu Electric Power Company has applied to the regulator to make additional modifications to increase safety further.

Sendai 460 (Kyushu)
Sendai (Image: Kyushu)

Kyushu announced yesterday that it has applied to the Nuclear Regulation Authority (NRA) for "permission for a change in its reactor installation licence". The company intends to construct a "facility for dealing with [a] specific accident and permanent direct current power equipment".

The utility said, in response to the new safety standards introduced in July 2013, it will establish a facility "which has the capability to prevent damage of the containment vessel needed for the times when there is loss of the cooling functions and subsequent damage of the reactor".

The facility will feature equipment that can reduce the reactor coolant pressure boundary; cool the inside of the reactor and containment vessels; prevent damage to the containment vessel due to excessive pressure or a hydrogen explosion; an additional back-up power supply; and a control room for operating this equipment in an emergency.

Kyushu also plans to upgrade the Sendai plant's power supply infrastructure. It will double the number of power transmission lines from three to six and modernize the extra-high voltage switchyard to improve reliability.

Under Japan's revised safety standards, plant operators are required to add certain safety-enhancing equipment within five years of receiving NRA's approval of a reactor engineering work program.

Kyushu's engineering work program for units 1 and 2 of the Sendai plant were approved by the NRA approved in March and May, respectively.

Sendai 1 was the first of Japan's operable reactors to resume operation since September 2013 when it restarted in August. The restart of unit 2 followed in October.

Researched and written
by World Nuclear News