Japan’s Fukushima nuclear plant operators on Friday confirmed that radioactive water had leaked from one of its storage tanks but the contaminated liquid was contained.

The technicians at the accident-struck plant detected the leak on Wednesday, Efe news reported.

The leak was detected in a cylindrical steel tank, and was believed to be a problem with the tank’s welding.

The Fukushima plant’s operator — Tokyo Electric Power Company (Tepco) — calculated that around 32 litres of the radioactive liquid, with a contamination level of 590,000 Becquerel per litre, had spilled out.

The power company, however, confirmed that the leak had stagnated around the tank’s perimeter and did not leave the area.

The water from the damaged tank was decanted into another to prevent further leakage.

Tanks susceptible to spills are progressively replaced by Tepco to address such problems. But as there are thousands of them, replacement within a short period has been difficult.

The refrigerant, which is kept inside the tanks, is used to keep cold the reactors damaged by the March 2011 tsunami.

Managing hundreds of tons of radioactive water that the plant generates each day is one of the main challenges that the plant’s technicians face.