The Irish Sea was contaminated by radioactive caesium - 137 from the former Sellafield nuclear fuel processing plant and nuclear accidents , such as the one at the Fukushima Daiichi Nuclear Power Plant in 2011 , may also cause radioactive material to seep into the sea .
The Irish Sea was contaminated by radioactive caesium - 137 from the former Sellafield nuclear fuel processing plant . 
 Nuclear accidents as at the Fukushima Daiichi Nuclear Power Plant in 2011 may pollute the sea .