NUCLEAR POWER plants in the UK have been inadequately designed against the threat of terrorist attack, according to a leading nuclear engineer.
Consultant Dr John Large says the possibility of such an attack was considered so remote in the past that no provision has been made in the design and construction of the UK's power stations.
His startling findings are contained in a report commissioned by anti-nulcear environmental group Greenpeace International after the 11 September attacks on New York (News last week).
Large has an international reputation, and has previously advised the Russian government on the operation to raise the Kursk nuclear submarine in 2001.
He has also advised the government of Gibraltar in its dispute with the Royal Navy over emergency repairs to the nuclear submarine HMS Tireless in 2000.
His report deals with possible scenarios for terrorist attack, using information available in the public domain.
'The results are disturbing. The nuclear industry designs its plants against natural and accidentally occurring hazards against human error, ' he says.
'Risk of different events is gauged by probabilistic assessment. But there is no provision against intentional and intelligently driven acts of terrorism as the likelihood of these was previously considered so remote that they could be discounted, ' says Large.
The risk of an aircraft accidentally hitting a nuclear power plant did not have to be considered in safety cases for nuclear reactors until 1979. It was not built into risk assessments for chemical separation and nuclear fuel plants such as Sellafield until 1983, the report says.
'This means that plants built before this time will have no significant planned defence against aircraft impact, ' says Large.
'Those such as Sellafield are almost totally ill-prepared for a terrorist attack from the air. The design and construction of the buildings date from a period of over 50 years, and many of the older buildings would just not withstand an aircraft crash and subsequent aviation fuel fire.
And some of the buildings, now redundant for the original purpose, have been crudely adapted for storage of large quantities of radioactive materials for which they are clearly unsuited, ' Large's report says.
At Sellafield, one building holds over 1,000m 3of radioactive kerosine which could explode with catastrophic consequences if involved in a fire.
'Around 250 jumbo jets alone pass over the north west of England every week along a flight path from where Sellafield can be seen. If a plane was hijacked, this would leave as little as four minutes for action to be taken to stop it flying into the plant, ' says Large.
In cases where an aircraft plane crashing into a facility has been considered by engineers, the risk assessments are based on historical aircraft crash data, and the chances of a relatively small object (the aircraft) hitting a much larger one (the plant) in a very large geographical area.
'This gives very low probability values, greater than the order of one in 10M, ' says Large. 'Because the chance is seen as so low, the nuclear industry considers there to be little justification in installing additional features or in beefing up structures to provide aircraft crash resistance, ' says Large.
The report says that the Sizewell B safety case in 1987 placed the probability of a large jet liner accidentally hitting the facility at more than one in 70M. This was so remote that the design only considered impact from a light aircraft such as a Piper Cherokee.
The report says an entirely different picture emerges if terrorist attack is considered.
'Applied to 11 September, then the hit rate was three out of four airborne aircraft. In other words, the hijackers had obtained sufficient flying skills to ensure that once the aircraft had been commandeered, the mission would have a high, almost certain rate of achieving its objective, ' the report says.
Apart from the lack of blast strengthening measures, the report also shows that the arrangement of buildings in facilities has not been designed with protection against attack in mind.
'The design of the most modern plants does not seem to provide that much defence (in terms of containment surety and segregation of hazardous materials) against an aerial attack, ' says Large. He also estimates that one fifth of the UK's nuclear plants could be vulnerable to van bomb attack.
Large says some of what he found caused him such concern that he decided against publishing it.
The report concludes that an attack could result in serious nuclear contamination.
INFOPLUS www. nceplus.co.uk/magazine/ wtc