The investigation by the Health and Safety Executive's Nuclear Directorate into this incident is complete. The incident is classified as level 1 under the International Atomic Energy Agency's International Nuclear Events Scale. This level is defined as “an anomaly beyond the authorised operating regime” and is one class above the lowest category of 0. The facility operator, British Energy, is legally obliged by its nuclear site licence to provide adequate arrangements for investigating incidents on the site and conducted an investigation into the June 2008 incident. In line with its established policy for such incidents, the Nuclear Directorate's investigation consisted of a review of British Energy's own investigation and concluded that this was satisfactory. The key change made as a result of the investigation was that British Energy put in place improvements to its maintenance arrangements at Hartlepool nuclear power station.