A vitrification (converting the waste into a large glass block) plant at Sellafield enables reprocessed high level waste to be solidified in glass blocks, sealed in stainless steel cans and placed in a carefully controlled storage facility. In its 1995 Policy Review the Government concluded that underground disposal was the favoured option for the long-term management of vitrified high level waste and reported that it was putting in hand development of a research strategy, with the aim of producing a statement of future intent in this area. It also concluded that a repository for the disposal of low and intermediate level radioactive waste should be constructed as soon as reasonably practicable. In the meantime disposal of low level waste by shallow burial at the Drigg site in Cumbria would continue.

Very low levels of radioactivity should be released from nuclear plant in gaseous emissions via stacks or in liquid effluent discharged to the sea. These releases are instructed to be kept below authorised limits set by the Environment Agencies, using a variety of techniques such as filtration and ion-exchange treatments. These limits ensure that the levels of radioactivity released to the environment are negligible compared with natural background levels. The discharges are monitored by both the nuclear industry and the Ministry of Agriculture, Fisheries and Food and the results of the monitoring are published regularly. As a result of these controls, population radiation exposure due to discharges from a nuclear power station is about the same as that due to the emissions from a coal-fired station, arising from the traces of natural radioactivity in the coal.

Everyone is exposed to background radiation from the sun and outer space and from the natural radioactivity in rocks, soil, buildings and diet. These sources account for 85% of the average person's annual radiation dose andmost ofthe rest comes from medical sources such as X-rays.

The contribution from nuclear industry discharges amounts to less than 0.1% of the total. Over a yearthis amounts to less than the radiation dose received from eating one brazilnut. (These nuts naturally accumulate radioactive elements from the soilduring growth.)

Despite the rigorous control of radioactive discharges from power stations, it has been suggested that these increase the risk of childhood leukaemia, and links have been claimed at some nuclear sites. This suggested association has been the subject of intensive research over the past twenty years. The latest authoritative study in England and Wales by Oxford University researchers, published in the British Medical Journal in 1994, used a very sensitive, new technique for detecting raised incidence of disease near a suspected source of risk.

Whilst an excess of childhood leukaemia and related diseases near Sellafield was clearly apparent, the authors concluded that there was no evidence of a general increase of these diseases around all nuclear installations. A similar conclusion was reached in a recent study in Scotland. Other possible explanations have been put forward toexplain the excess near Sellafield, notably the Kinlen hypothesis that leukaemia is a rare response to a common infection whose spread is facilitated by population mixing, as in new towns, for example. Cumbrians Opposed to a Radioactive Environment (CORE) pointed out that

"No leukaemias were recorded until several years after the start of military plutonium operations in West Cumbria in the early 1950s, despite the significant influx of almost 8000 construction workers in the 1940s".

CORE also detailed BNFL's funding links with Newcastle University and with the Imperial Cancer Research Fund and added that some small Cumbrian villages close to the Irish Sea and where there has been little or no population mixing, have significantly high rates of childhood leukaemia.

The Irish Sea factor was also picked up by the Low Level Radiation Campaign. The Irish Sea is heavily contaminated with insoluble particles of plutonium and uranium which migrate inland and are retained in the lymph nodes after inhalation. The lymphatic system is recognised as a critical organ for leukaemogenesis, and post mortem analysis of nuclear workers and members of the Cumbrian public has shown extremely high concentrations of plutonium in tracheo-bronchial lymph nodes.

Research is continuing worldwide into the causative mechanisms for human leukaemia, but until a scientific mechanism that explains how it develops can be established scientist will continue to say that no linkhas been proven to the nuclear industry while action groups will maintain that the link is obvious.

Nuclear Accidents

The Windscale Fire - Sellafield accident

The Three Mile Island Incident

The Chernobyl disaster

• Radiation reactor accidents occur almost exclusively at well-characterized fixed facilities, like nuclear reactors or nuclear power plants, or along prescribed transit routes when radioactive materials are moved.
• Typically, facility operators and local officials have formal response plans and practice response operations.
• For accidents at fixed facilities, like a nuclear power plant, there is likely to be a window of time before the release of radiation starts, as opposed to an improvised nuclear device (IND) or a nuclear bomb, which may be initiated without any advanced warning.
• With nuclear reactor sabotage incidents, there may be less warning time.
• Victims can have both exposure and contamination.
• Contamination with radioactive iodine has almost exclusively been identified in the aftermath of accidents at nuclear reactors, although some exposure may occur with other types of radiological events. The need for prophylaxis/treatment with potassium iodide will be determined by officials managing the event, and instructions to potentially exposed populations will be given. Typically the most significant route of radioactive iodine uptake is ingestion, although inhalation may also occur.

(Taken from US Department of Health and Human Services)