A team of South Korean experts has completed its examination of the crippled Fukushima Daiichi nuclear power plant to assess the safety of Japan's plan to discharge treated and diluted water into the ocean.

The delegation of about 20 members includes senior officials of South Korea's Nuclear Safety and Security Commission, as well as marine environment specialists.

They examined the nuclear plant on Wednesday, the final day of their two-day visit.

Yoo Guk-hee, the chief of the delegation, later told reporters that the team looked at equipment for diluting treated water and releasing it into the sea.

He also said they checked facilities including one for analyzing radioactive substances in treated water.

On Thursday, the experts are scheduled to have final talks with Japanese government officials and others in Tokyo. They are due to return to South Korea on Friday.

Japan plans to release treated water after diluting it to reduce tritium levels to one-seventh of the World Health Organization's safety standards for drinking water.

The plant's operator, Tokyo Electric Power Company, is preparing to start releasing water by around this summer.

Japan's government says it hopes understanding will be deepened and concerns dispelled in South Korea through the visit.

South Korea's government says the purpose of the visit was to meticulously verify the effects on South Korean waters and marine products and to promptly take necessary steps.