23 Feb (NucNet): Recommendations for future operations at the Petten high-flux reactor (HFR) in the Netherlands have been published today by the International Atomic Energy Agency (IAEA).

An IAEA-led international team of nuclear reactor safety experts completed a safety review mission at the recently restarted HFR on 18 February 2009.

The mission was conducted at the request of the Dutch government to review a set of previous evaluations made by the country�s regulatory authority regarding the reactor�s safety.

On 12 February Dutch authorities gave permission for a one-year restart of the HFR, which is operated by the Nuclear Research & Consultancy Group (NRG) on behalf of the EU�s Joint Research Centre.

The HFR was shut down in 2008 for a planned maintenance and repair period, but did not start up again following the discovery of a gas bubble stream that had been escaping periodically into the primary cooling water system. The cause of deformations and the gas bubble stream was corrosion on the concrete side of the vessel which affected the aluminium material of the vessel.

�One of the main requirements of the (Dutch) regulatory authority was that the reactor must be immediately shut down if any leakage is detected. The IAEA strongly supports this requirement,� the IAEA said today.

�The reactor is authorised by the regulatory authority of the Netherlands to remain operational for an interim year until 1 March 2010 to allow for preparation of repairs. Repair of the pipe degradations is expected to last several months and is scheduled to begin in March 2010.�

Recommendations from the IAEA mission include:

� Performance of the monitoring system for leaks should be rigorously checked during the interim year of operation;

� Temporary operation of the HFR cannot be extended beyond 1 March 2010;

� In case of any detected leakage from the coolant pipes, the reactor should be shut down immediately and repaired before restarting.

The international team comprised one IAEA staff member and external experts from Argentina, Canada, France, India and South Africa.

The IAEA�s main conclusions and recommendations were presented to the Dutch Ministry of Housing, Spatial Planning and the Environment, and several other ministries. The team also provided a summary of its findings to the Netherlands Regulatory Authority. The final report will be submitted within two weeks.

The HFR at Petten is one of five research reactors in the world that produces radioactive medical isotopes, used an estimated 40 million times annually for cancer treatment and the diagnosis of heart attacks. Prolonged outages at any of these five reactors have a far-reaching impact on medical treatments and diagnoses for patients around the globe, the IAEA added.

>>Related reports in the NucNet database (available to subscribers)

Petten High-Flux Reactor Scheduled To Restart In February 2009 (News No. 77, 15 October 2008)

NRG Gets Permission To Restart Petten Research Reactor (World Nuclear Review No. 7, 13 February 2009)

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