The Sellafield nuclear waste dump is to be prosecuted for alleged information technology security offences, the industry watchdog has said. The Office for Nuclear Regulation (ONR) said on Thursday that it had notified the state-owned Cumbrian nuclear company that it would be prosecuted under industry security regulations. The prosecution follows the Guardian’s revelations last year of multiple cyber failings at the vast site, part of a year-long investigation into cyber hacking, radioactive contamination and an unhealthy workplace culture at Sellafield. The ONR said: “These charges relate to alleged information technology security offences during a four-year period between 2019 and early 2023. There is no suggestion that public safety has been compromised as a result of these issues. The decision to begin legal proceedings follows an investigation by ONR, the UK’s independent nuclear regulator.” Sellafield, which has more than 11,000 staff, was placed into a form of “special measures” for consistent failings on cybersecurity in 2022, according to sources at the ONR and the security services. Among the Guardian’s revelations in December were that groups linked …