Up to 44 MB of classified technical data on Japanese nuclear plants has been posted on the internet after a worker’s computer was infected with a virus.
According to the Nuclear and Industrial Safety Agency, the information included reports and manuals on regular inspections and maintenance of power generation facilities in Hokkaido, Fukui and Kagoshima. The information came from seven power companies and four other utility industry firms and included photos of power generation facilities and workers' medical files at at least two reactor sites.
The infected computer apparently belonged to a Mitsubishi Electric Plant Engineering Corp maintenance engineer. When infected, the virus caused the pre-installed file sharing software Winny to send out data via the internet.
A spokesman has said that the government will now strengthen the management of nuclear information following the revelations.
An investigation into whether the data included sensitive information on nuclear materials is also currently underway.
"We haven't determined whether there was a leak of critically important information relating to the security of nuclear materials," Japan's chief cabinet secretary Hiroyuki Hosoda reportedly said.