TEPCO President Naomi Hirose told Abe that a decision on the reactors would be made by the end of the year, the prime minister said.
Abe said he urged TEPCO to ensure it has enough funding on hand to take care of urgent work needed to clear the way for the plant's decommissioning, and that Hirose promised to obtain 1 trillion yen ($10 billion) in addition to a similar amount it has already set aside.
Decommissioning multiple melted reactors is an unprecedented challenge, and experts say Fukushima's cleanup will be far more difficult than after the Three Mile Island nuclear accident in the United States in 1979.
The prime minister said he stood by the reassurance about Tokyo's safety that he gave to the International Olympic Committee before the city of 35 million was awarded the right to host the 2020 summer games earlier this month.
“One of the main purposes of this visit was to see it for myself, after I made those remarks on how the contaminated water has been handled,” Abe said.
Officials have acknowledged that radiation-contaminated groundwater has been seeping into the Pacific Ocean since soon after meltdowns and explosions crippled the plant following a massive earthquake and tsunami.
Abe said he was convinced that all of the contaminated water had been contained.
“In light of that, I will work hard to counter rumors questioning the safety of the Fukushima plant,” he said.
Abe was shown some of the 1,000 tanks containing radioactive water, water treatment equipment and an underground chemical dam being installed along the coast—steps meant to contain the water leakage, which experts say is a major obstacle for the decades-long cleanup process.
Wearing hazmat coveralls, a face mask and an orange helmet, Abe rushed with his entourage from one site to another, spending only several minutes at each.
Abe's adamant reassurance to the IOC that the leaks are “under control” has backfired at home, as many Japanese believe he was glossing over problems at the plant.
Thursday's plant visit was Abe's second since taking office in December, when he took his first tour on a bus.
Hours before the IOC chose Tokyo to host the 2020 Olympics, Abe gave a speech declaring that radioactive contaminants from the leakage had no impact on seawater outside the bay near the plant. Tokyo was not at risk, he insisted. Fukushima is about 250 kilometers (160 miles) northeast of the capital.
Senior TEPCO official Kazuhiko Yamashita told opposition Democratic Party of Japan lawmakers last week that the water situation was “not under control,” appearing to contradict Abe. DPJ leaders said they would demand that Abe explain his remarks to the IOC.
TEPCO later said Yamashita was referring to isolated incidents and had not contradicted Abe's comments.
The most heavily radiated water pools inside the reactor and turbine basements, where waste cooling water that leaked out of melted reactors has gathered, have mixed with groundwater seeping through cracks in the damaged buildings, generating 800 tons of contaminated water per day.
Much of the water is being pumped out and partially treated—half is recycled as cooling water, the other half stored in tanks. The plant has 350,000 tons of water kept in the 1,000 tanks.
The chairman of Japan's Nuclear Regulation Authority, Shunichi Tanaka, has proposed using a new water treatment machine capable of removing all radioactive elements apart from less toxic tritium so the water can be eventually released into the ocean.
That equipment, which Abe saw during Thursday's tour, is under repair due to corrosion, and tests are to resume later this year.
The government is funding the development of more advanced water treatment equipment and paying for a costly ice wall to surround the reactor and turbine buildings and prevent them from contaminating outside groundwater.
