This section describes what the trains carry, where and when they travel, and why they are a danger. The next section, Accidents and Risks in Transport, describes some problems with the trains and the state of the track on some parts of the routes.
The trains carry used nuclear fuel rods, which are extremely radioactive, from nuclear power stations (mainly situated on the coast) to Sellafield in Cumbria. The fuel rods are carried in 50 ton containers called 'flasks' (because they hold water to prevent the rods overheating).
There are two main types of reactors in UK power stations, which use somewhat different fuel. The types are known as Magnox (Magnesium alloy is used to clad the fuel rods) and AGR (Advanced Gas cooled Reactor). There is also one PWR (Pressurized Water Reactor), at Sizewell. After nuclear fuel has been used it is far more radioactive and requires heavy shielding. So although new fuel rods are usually transported by road, used rods are transported by rail. "Nuclear trains" is a short way to refer to the trains which carry used fuel rods from nuclear power stations.
The used rods contain uranium and plutonium and are extremely radioactive. When taken from the reactor they are stored in cooling ponds at the power station for up to 18 months (thus contaminating the water). The rods are then loaded into water-filled lead-lined steel containers called 'flasks', onto which a lid is bolted. Each 50-ton flask is then washed down to remove radioactive surface contamination, loaded onto a lorry which carries it to the nearest railhead, then transferred onto a flat-bed railway waggon (which weighs about 100 tons). A metal cover or 'cabin' is placed over each flask.
Each flask contains about 2 tons of rods, and about 1 million Curies of radioactivity, or 37 thousand million million Bequerels (one Bequerel is equivalent to one click on a geiger counter; the Hiroshima bomb released about 3 million Curies). The outside surface of these flasks emit radiation well above background levels: even the 14-inch thick walls are inadequate shielding against the highly radioactive rods. If the water coolant was lost, the fuel rods would overheat then combust, dispersing a massive dose of radioactivity into the atmosphere. They are a highly dangerous cargo, which the industry insist on calling "spent fuel", thus implying that it is neither waste nor especially hazardous.
From the railheads near Sizewell and Dungeness power stations the trains carry this nuclear waste through London to Willesden Junction, where they are marshalled into one train which later travels up to Sellafield in Cumbria. Here the rods (along with those from other power stations) are 'reprocessed', initially by stripping the now radioactive cladding and dissolving the contents in nitric acid. Uranium and plutonium are eventually extracted and stored (and currently unused), and in the process the volume of nuclear waste is multiplied 160-fold. Magnox spent fuel is reprocessed in one plant (building B205) and AGR and PWR fuel is reprocessed in THORP (Thermal Oxide Reprocessing Plant).
Nuclear waste also arrives in the UK from overseas (Germany, Switzerland, Japan), but these flasks are shipped direct to Barrow-in-Furness and only seen on the short part of the rail network between Barrow and Sellafield.
One contentious issue is whether the fuel rods need to be reprocessed and so need to be transported at all. The decision to store fuel rods temporarily in cooling ponds leads to their corrosion, in which case they must be reprocessed. But there is an alternative of dry storage on-site. Another issue is why the trains are routed through large centres of population, such as London and Rugby, when less populous routes are available. Clearly that decision is based on cost and convenience, not minimising risk.
The trains are easily recognized by the large grey or cream 'cabins' covering the flasks, the long flat-bed waggons, and the short trains. Leaving nearby the power stations there are typically no more than three waggons to a train, but marshalled further along the route there might be up to ten. They are now usually pulled by engines labelled DRS (Direct Rail Services) - the picture above shows a flask being shunted. There used to be a guard's van at the rear of the train, but this was stopped to save money. The trains also make the return journey with the empty flasks, but sometimes take slightly different routes.
The commercial nuclear power stations are at Bradwell (now closed), Dungeness and Sizewell (marshalled at Willesden), Hartlepool and Hunterston (marshalled at Carlisle), Hinkley and Wylfa (marshalled at Warrington), and Heysham. There are also 'layover' sites where trains can wait for their allotted slots in the timetable.
The trains typically travel once or twice a week, but this depends on several factors: the number of fuel rods in the ponds, the length of time they have been there, and the current state of the relevant reprocessing plant at Sellafield. For example, at the time of this writing there is a problem with the reprocessing at Sellafield, and some stations (eg. Sizewell) have been told they may have to hold their fuel rods 2 or 3 years.
The timetable is supposed to be secret, but details have been openly published in Freightmaster (a trainspotting publication) for years. Nonetheless, emergency planning officers have been refused this information, even though it is vital for effective emergency plans in the event of a nuclear accident. These facts show that the secrecy has nothing to do with preventing terrorist incidents but is simply the typical attitude of an arrogant and conceited business management: we're the experts, an accident won't happen, so you don't need to know.
Although many people are still unaware that highly dangerous nuclear waste is routinely carried on the rail network, it is one of the more visible aspects of the nuclear industry - except for those who live near a nuclear power station, and these are often in relatively remote locations. When BNFL decided to move its marshalling from Willesden to neraby Cricklewood the local population mounted a successful campaign to prevent this. Unfortunately, most of the campaigners stopped when they had achieved their immediate goal, not fully taking in the fact that a serious accident in any adjacent borough could be just as devastating (depending on wind direction).
As well as a target for protest (trains have been stopped, graffittied and paint-bombed) they are also a potential target for terrorists. It is well within the capabilities of a few committed people to break the containment of a flask and release the radiation, should they be mad enough to try. The flasks have neither been designed nor tested against army piercing weapons nor shaped explosive charges. A suicide squad might even undo the bolted lid. Any breach of containment of the flasks resulting in a loss of water would result in disaster.
The Mark Thomas Comedy Product showed, on a TV program 10/2/99, how easy it would be for terrorists to intercept a nuclear waste train from Dungeness. There are quiet spots on the line from Dungeness and Sizewell power stations, the trains are unguarded, and they no longer carry a guards van (so the flasks can only be observed from one view. Security at nuclear power stations is equally lax: Greenpeace activists have entered the Sizewell B power station several times.
The main points of this section are
Here are some organizations that may have more details on nuclear fuel rod transport or local conditions at power stations.