DATA provided by EDF Energy on radioactive emissions from the Sizewell B nuclear power station is 'inadequate', according to a watchdog group which is calling for further details.

The company, owner and operator of the nuclear plant, was asked to produce data about the low-level emissions which occur when the reactor is shut down for refuelling and routine maintenance, an event known as an 'outage' and necessary in pressurised water reactors (PWRS) about every 18 months.

However, the figures it provided have now been described as inadequate by the Sizewell Stakeholder Group (SSG), which is calling for more details. Some members of the group are concerned about a study in Germany which suggests there is an increased risk of childhood leukaemia around that country's nuclear plants.

The members want to know hour-by-hour emission levels and the radio-nuclides involved. Annual Sizewell B radiation emissions – monitored by Government agencies – are well within statutory limits.

However, there is concern over a disclosure in the German study that a high percentage of the annual emissions from nuclear plants occur during the refuelling outages. The last outage at Sizewell lasted 50 days and occurred last autumn.

The SSG has now decided to send a letter to EDF Energy calling for more information on emissions during outages.

'This data and the scrutiny we will put it to is necessary due to concerns, repeatedly expressed at SSG meetings, that there could be a link between the high discharge spikes at outage times and the elevated levels of childhood leukaemia identified at all German nuclear power plants with similar evidence from Switzerland and France supporting this hypothesis,' the letter says.

The group is also asking EDF to support its call for a review of a report by the UK's Committee on Medical Aspects of Radiation in the Environment (COMARE) which has dismissed the German report as unreliable.

John Benn, Sizewell B plant manager, said EDF would respond to the SSG letter by the end of September. 'We are working on the data and have contacted the German authorities to inquire about their recording methodology,' he said.