Last week, Camas Associated Asphalt Ltd, a road-surfacing company based in Henley on Thames, Oxfordshire, was fined a record pounds 36,000 for losing the source and for failing to report the loss for more than a year. The company is now considering an appeal.
The source is a "Troxler gauge" and is the first instrument of its kind known to have been lost in Britain. Designed to measure the moisture content and density of road surfaces, the device contains caesium-137 - which emits gamma radiation - and an americium/beryllium source of neutrons.
The case highlights how widespread is the use of nuclear techniques in industries that have no connection with nuclear power. Michael Williams, of the Health and Safety Executive's Policy Branch, says more than 65,000 people in Britain are classified as radiation workers. The HSE is concerned, he said in an interview, that while the nuclear industry has vastly reduced its workers' radiation doses, other companies outside civil nuclear power have not followed suit.
As well as losing the source, Camas failed to keep complete records of doses to its staff with an approved dosimetry service, as required by radiation safety regulations, to prevent unnecessary exposure to operators. About half the company's registered radiation workers did not have proper "film badges" to record their radiation doses.
Of the company's efforts to record the whereabouts of the gauge, Paul Appleton, prosecuting for the HSE, said: "Our regulations require a daily check on these machines. ... What this company was doing was to record as and when it was moving from site to site and even then it managed to make a mess of it."
But Bill Heather, the company's technical and development director, said after the trial: "We were surprised at the level of the fines. It was a first offence for a company that prides itself on complying with the regulations. We've been operating the gauge for 12-odd years without any problems or incidents at all. We are awaiting advice from our solicitor over whether to appeal." Camas, which employs between 850 and 900 full- time staff, plus 200-300 subcontractors in peak season, has 10 regional offices across the country, and a turnover of about pounds 110m last year.
Mr Williams said that since 1986 overall radiation doses to workers have been declining. He believes the message is finally getting home that it is not enough simply to comply with dose limits: "There is also a requirement to restrict radiation exposures so that they are as low as is reasonably achievable. Since 1986, the number of people getting more than 15 millisieverts a year has dropped by a factor of 10, from more than 2,000 to around 200 in 1993." The limit for workers is 50 millisieverts, so the majority are being kept at less than a third of the legal maximum.
But while the nuclear power industry has been at the forefront in reducing worker doses, there has been little improvement in other industries in recent years. Mr Williams says that, in part, managers did not understand as well as they should what the dosimetry requirements were.
Rather than adopting a punitive approach, the HSE has been distributing leaflets and information sheets to companies explaining the requirements and how to meet them. Mr Williams feels radiation safety is a matter of good management which will have a commercial payoff - the job will be done better - as well as reducing radiation dose.Reuse content