The US Nuclear Regulatory Commission says it will increase oversight of the Three Mile Island nuclear power plant in central Pennsylvania to ensure that safety equipment is protected from severe flooding.
The NRC said on Tuesday that its inspectors had found an external flood barrier deficiency during an inspection of Exelon Corporation's 805-megawatt Three Mile Island nuclear power plant last autumn, Reuters reported.
The NRC has conducted many inspections of the United States’ nuclear reactors following the Fukushima nuclear disaster in Japan in 2011.
On March 11, 2011, a magnitude 9 earthquake off the northeast coast of Japan's main island set off a devastating tsunami and was followed by more than 50 aftershocks.
The incident led to fires, explosions, or partial meltdowns of six reactor units of the Fukushima Daiichi nuclear power plant after it knocked out power to the facility's cooling systems. A radiation leak followed and nuclear fallout was reported in many places across the world.
The NRC said its inspectors discovered that Exelon Corporation had failed to identify and fix a problem involving pipes holding electrical cables at the Three Mile Island nuclear power plant.
The agency added that the pipes, placed in the plant's air intake tunnel, were not correctly sealed to maintain the integrity of the flood barrier.
The NRC noted that in the case of heavy flooding the problem could threaten plant safety equipment.
Three Mile Island, the site of the worst accident in US commercial nuclear power plant history, is on an island in the Susquehanna River about 24 kilometers southeast of Harrisburg, the capital of Pennsylvania.
On March, 28, 1979, a combination of mechanical failure and human error caused a partial meltdown at the nuclear power plant that resulted in the release of radioactive gases and radioactive iodine into the environment.
The NRC approved licenses to build two new nuclear reactors in February 2012, the first authorized in over 30 years after the accident.