The nuclear energy centre at Petten on the Dutch North Sea coast is concerned about the supply of medical isotopes to hospitals around the world while its back-up reactor in Canada remains shut down. The Petten reactor is running at reduced capacity owing to maintenance work, and most of the production had been shifted to the Canadian facility at Chalk River. Between them the reactors produce two-thirds of the world's medical isotopes.

Hospitals are beginning to experience a shortage of reactor-produced isotopes. For its bone scans, Sherbrooke University Hospital in Quebec for instance is resorting to older technology, using home-made radio-active sodium fluoride isotopes.

Medical isotopes are vital for diagnosing cancer and heart and bone diseases. If neither the Canadian reactor and the Dutch one are producing enough, "it would be pretty difficult to see how the medical community could manage to cope," Petten Commercial Manager Kevin Charlton told the Toronto Sun. Last week, Petten stepped up production despite its own maintenance work, using its remaing reactor capacity for isotope formation instead of industrial production and scientific experiments.

Conservative VVD MP Halbe Zijlstra raised the matter on Monday in the Lower House. "Everybody agrees we need a new reactor," he suggested. Mr Zijlstra is worried about the cabinet's apparent lack of activity to ensure a continued supply of isotopes.

Chalk River, located 180 kms northwest of Ottawa, shut down last month after leaks were discovered in the heavy water system. Repairs may take until early 2010. Petten, too, will close down during July for inspections.