Japan's stricken nuclear power plant has leaked more than 160 gallons of water, forcing it to briefly suspend cooling operations at a spent-fuel pond at the weekend, the plant's operator and domestic media said.
The Fukushima plant, on the coast north of Tokyo, was wrecked by a huge earthquake and tsunami in March last year, triggering the evacuation of around 80,000 people in the world's worst nuclear crisis in 25 years.
The operator of the complex, the Tokyo Electric Power Co (Tepco), reported two main leakages on its website on Sunday, one from a pump near the plant's office building and another from a back-up cooling system at reactor No.4.
"The cooling water is from a filtrate tank for fire extinction and doesn't contain radioactive materials," Tepco said of the incident at reactor No. 4. It added that some water from the other leakage had flowed into a drain and "we are examining whether this water has flowed into the ocean or not."
The Nikkei newspaper Monday quoted Tepco as saying around 40 liters (10.6 gallons) had leaked from the pool-cooling system of the No. 4 reactor Sunday morning, with probably 600 liters (158.5 gallons) of purified water leaking from another point. Water had also leaked at other facilities within the complex, the Nikkei added.
However, the Nikkei newspaper quoted Tepco Monday as saying that it believed no water had escaped into the sea.
"The leakage is believed to have been caused by freezing due to cold weather, and the leaked water included radioactively contaminated water that has been purified," the Nikkei said in its online edition, quoting Tepco. "The contamination level is low."
Meanwhile, Japan's deputy prime minister has acknowledged that the government failed to take minutes of 10 meetings last year on the response to the country's disasters and nuclear crisis and called for officials to compile reports on the meetings retroactively.
The missing minutes have become a hot political debate, with opposition lawmakers saying they are necessary to provide a transparent record of the government's discussion after the March 11 earthquake and tsunami touched off the worst nuclear accident since Chernobyl in 1986.
Deputy Prime Minister Katsuya Okada confirmed Friday that the minutes were not fully recorded at the time and called for them to be written up, retroactively, by the end of February. Three of the meetings during the chaotic period had no record at all, not even an agenda, including a government nuclear crisis meeting headed by the prime minister.
Okada has set up a panel to investigate the extent of the problem and its cause.
The missing minutes are the latest example of the government missteps in disclosing information.
Japanese authorities and regulators already have been repeatedly criticized for how they handled information amid the unfolding nuclear crisis. Officials initially denied that the reactors had melted down, and have been accused of playing down the health risks of exposure to radiation.
The government also kept secret a worst-case scenario that tens of millions of people, including Tokyo residents, might need to leave their homes, according to a report obtained recently by The Associated Press.