Japan: The core of a nuclear reactor may have been punctured.

Japanese nuclear officials today suspected that the core of a reactor at the Fukushima I nuclear power plant may have been breached, increasing the risk of high levels of radiation being released into the environment.

“There is a possibility that the reactor has been damaged somewhere,” said Hidehiko Nishiyama, a spokesman for Japan’s nuclear safety agency. But he added, “our data shows that the reactor still maintains some of its functions to prevent radiation from escaping.”

He said damage may have occurred in the core of reactor number 3, but it was not extensive.

Reactor No. 3 is believed to have suffered the most damage of the six reactors at Fukushima I.

Authorities say damage may also have occurred to other components, such as the pumping system or the spent fuel tank.

Plant officials are struggling to keep water cool around the nuclear fuel rods at the core of the reactor. The March 11 earthquake and tsunami knocked out power and damaged the reactors’ cooling systems.

Experts believe the reactor core may have been damaged after a hydrogen explosion on March 14, causing the outermost building containing the reactor to be blown away.

Reactor No. 3 is considered the most severely damaged of the six reactors at Fukushima I. It contains 170 tons of radioactive fuel in its core. Previous leaks have been caused by deliberate attempts by authorities to release small amounts of steam through valves to prevent the core from exploding. However, authorities may have failed to control the amount of radiation released from the leak, allowing it to escape into the surrounding environment and the air.

Plant authorities have halted rescue work at reactors 1 and 3 today to check radiation levels.

According to Dan Tri