Mo-99 production resumes at troubled European isotope reactor

The High Flux Reactor in Petten, the Netherlands, is back online after its lengthy unscheduled closure, following special approval from the Dutch Council of Ministers.

The decision should allow supplies of molybdenum-99 to stabilize after six months of periodic shortages and avert an immediate supply crunch. Both other sites in Europe that produce Mo-99 are currently closed for routine maintenance.

"With the restart of the HFR, it is expected that within a few days there will be sufficient availability of medical isotopes for the treatment of patients worldwide," said a statement from the Nuclear Research and Consultancy Group (NRG), the company that runs the Petten reactor.

The Dutch reactor was initially shut down in August 2008 after a small bubble jet was observed in its primary water cooling system. The coolant pipes are also known to have been deformed, with the pipe walls thinning from 9.5 mm to 3 or 4 mm in places.

Planned repairs to the primary cooling system have not yet been carried out. Dutch officials have nonetheless agreed that the reactor can begin operating again so long as additional safety measures are adhered to.

The NRG has fitted seals to contain water escaping from the pipes and installed additional systems to monitor for leaks. Deformations to the pipe work, first noticed in 2005, will be subject to an "intensified inspection regime."

An independent team of experts from the International Atomic Energy Agency will visit the site shortly to monitor the situation. If any irregularities are detected by IAEA officials or NRG staff, the reactor will be shut down immediately.

The NRG anticipates that it will take another 12 months before it can replace the damaged sections of the primary water cooling system. The repair itself will close the reactor again for two or three months.

For more information from the Diagnostic Imaging and SearchMedica archives:

Collaboration begins on U.S. Mo-99 production facility

High-volume production of Mo-99 appears feasible with low-grade uranium

European Mo-99 production at Petten may resume in February

Europe faces further Mo-99 supply woes