Tepco, Chubu Electric Power, Toshiba Corp. and Hitachi Ltd. said Wednesday they have agreed to discuss potential collaboration on nuclear power, as the industry faces a challenging business environment following the 2011 Fukushima crisis.

Amid lingering safety fears over nuclear plants, Tokyo Electric Power Company Holdings Inc., operator of the crippled Fukushima No. 1 nuclear complex, Chubu Electric Power Co. and the two major nuclear reactor builders said they will consider jointly developing human resources, technologies and supply chains.

Since the 2011 disaster, stricter safety requirements have been implemented and only nine reactors at five nuclear complexes nationwide have restarted operations. At the time of the disaster, Japan had 54 nuclear reactors for commercial use.

The four companies said the envisaged partnership is aimed at effectively operating and developing nuclear technologies, and that they plan to promote cooperation, especially in the boiling water reactor business.

But demand for nuclear energy in Japan is unlikely to recover to the pre-Fukushima disaster level.

Facing huge compensation payments and other costs stemming from the Fukushima disaster, Tepco is eager to resume operating two reactors at the Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture, but thus far it has failed to obtain necessary approvals from host municipalities.

Chubu Electric is also struggling with rising costs to maintain the Hamaoka nuclear plant in Shizuoka Prefecture, which remains offline.

Hit by ballooning costs, Hitachi has suspended a ¥3 trillion ($28 billion) nuclear plant project in Britain, while Toshiba decided in 2017 to exit the nuclear business outside Japan after incurring huge losses in the United States.