The company pleaded guilty to four charges brought by the Nuclear Installations Inspectorate (NII) alleging that the company had breached the site licence conditions at Sellafield. It is the company's third conviction for violating nuclear safety rules.
Magistrates at Whitehaven fined the company a total of pounds 6,000 and awarded the NII pounds 10,757 in costs. Jim Furness, a nuclear inspector whose department brought the prosecution, said: 'We decided to prosecute to underline the seriousness with which we viewed the loss of defence-in-depth provisions we expected BNFL to have in place.'
The court case follows an investigation by the NII into an incident in a building which stores containers of highly radioactive waste. The reprocessing plant at Sellafield produces highly active liquid wastes which have been stored since the 1950s in stainless steel tanks. Since 1991 the waste has been 'vitrified' (cast into glass blocks) which ought to make it easier and safer to store.
However, in April 1992, BNFL discovered that a safety interlock had been overridden. The interlock was intended to prevent the inadvertent opening of a heavy radiation-shielding door when there was a flask containing radioactive vitrified waste behind it.
Although the error was caught in time and no one was exposed to radiation, Mr Furness said that the overriding of the interlock 'bears features similar to an incident on 15 September 1991'. In that incident, in the vitrification plant itself, a cask had actually been raised while safety doors stood open.
The container of highly radioactive waste had been brought into a control cell for monitoring. The inner and outer doors should have been interlocked so that only one could be opened, but both were standing open. They had not been closed following maintenance work, and had anyone been standing near the doors they could have received a high radiation dose.
Fortunately an operator spotted the problem on a TV monitor. The NII investigated the incident, but decided not to prosecute. 'We had hoped that they would have eliminated that shortcoming from their safety systems. That was spelt out to them,' Mr Furness said.
He added that he was content with the measures that had now been put in place by BNFL following the latest incident, although safety always remained the licensee's responsibility while the inspectorate's job was to monitor the licensee's activities.
The NII has been notably reluctant to prosecute the nuclear industry in the past, having brought only six cases to court so far. A spokesman for the inspectorate said that only since 1989 had the NII been using prosecution 'as a means of administering control to the industry'.
BNFL was prosecuted for an earlier incident in which it had been transporting spent nuclear fuel around the site without radiation detection equipment.
It was also convicted of breaches of safety regulations following an incident in 1983 when the beaches of West Cumbria were polluted because of a discharge of radioactivity into the sea. In that case, however, the prosecution was not brought directly by the NII.Reuse content