Petten nuclear reactor
On 2009, the Argentine company INVAP (teamed with Spaniard group Isolux) was pre selected in the international tender called for the PALLAS project, for the procurement of a 80 MW nuclear reactor for the Dutch village of Petten  but on February 2010, the Dutch radiopharmaceutical producer Nuclear Research and Consultancy Group (NRG) extended the preparatory phase up to end of the year for financing 
The high flux reactor (HFR)
The high flux reactor in Petten has been in use since 1961. The first criticality was obtained the November 9th, 1961. The reactor was furnished by Allis-Chalmers.
The life span of the current HFR will end around 2015. It has already been decided that a new HFR (Pallas) will be constructed to start operating by this time.
From August 2008 the HFR was shut down due to corrosion of the pipes in its primary cooling circuit. The operator is expecting to bring the plant back on-line in February 2009.
The low flux reactor (LFR)
The low flux reactor has been in use since 1960. It has a capacity of 30 kW. The LFR is property of the Nuclear Research and Consultancy Group (NRG). The LFR is mainly used for the production of neutrons for biological and physical research.
Medical importance of Petten
Apart from its function as a research centre, Petten is also a large producer of radioactive material for the purpose of medical diagnosis and the treatment of cancer and contrast agents (Radiopharmaceuticals). The nuclear facilities at Petten supply 60% of the European demand for medical isotopes. Also at the high flux reactor, one of the neutron beam channels, which was originally installed for performing fundamental research, has been specially modified for the direct irradiation of patients. This allows use of neutrons for the treatment of tumors after saturation of these tumors with a pharmaceutical containing boron. When hit by a weak neutron beam, boron will locally emit radiation that will destroy the tumor. This technique is mainly suitable for the treatment of brain tumors.
In 2002, the High Flux Reactor was shut down for a few weeks because of two unrelated issues. There were indications of a weld defect in the reactor vessel and there were some concerns about the safety culture within the company. After completion of extensive research and the announcement of a series of additional measures, the reactor was put back into use.
As of 2006[update], only low-enriched uranium fuel is used at the facilities in Petten. As a result of political pressure from the United States and the International Atomic Energy Agency (IAEA), research reactors are no longer allowed to use highly enriched uranium fuel because of its potential use for the production of nuclear weapons.  However, the reactor continues to use highly enriched uranium targets for the production of medical isotopes.
2001: Frans Saris reports
Frans W. Saris, former director of ECN Petten, and former professor of physics and dean of mathematics and natural Sciences at the University of Leiden published in November his book "Darwin meets Einstein". In his book Saris mentioned two previously not noted incidents which he gives as the reason for his resigning from ECN and RTL nieuws:. Saris says the following
- "In the summer of 2001 I discovered that our nuclear research and consultancy group in Petten had secretly initiated the building of their own reprocessing plant, because the highly enriched uranium remnants from the Mo99 production could not be sent to Dounreay anymore. Issues of environmental impact and the non-proliferation treaty were waved aside by referring to the medical applications. I could block this development in time, but only after seeking the support from ECN's Supervisory Board.
- "On a winter night in December 2001 there was a power failure in North Holland, where Petten is located. The nuclear reactor is a research reactor, not a power reactor; it needs electricity to operate, for instance to pump cooling water. The reactor has a back-up cooling system to prevent meltdown of the core in case of a power failure. But this evening the back-up cooling system failed to come into action and the operators did not know what to do. There is an extra safety system by convection cooling for which the operators had to open a valve, but the control room was dark. When they reached for a torch that should have been there, it had been taken away by a colleague to work under his car. Trying their luck the operators put the valve of the convection cooling in what they thought was the 'open' position. But then the lights came back on and the operators discovered they had actually closed the back-up convection cooling system. Had the power failure lasted longer it would have meant meltdown and a major disaster. When I learned about this some months later - they thought they could keep it secret - I did not think I could take responsibility any longer and I resigned from the ECN."
- Argentina, a un paso de venderle un reactor nuclear a Holanda
- 'Bijna-meltdown in Petten in 2001' (in Dutch)
- quotes from "Darwin Meets Einstein: On the Meaning of Science", Frans Saris, November 2009, Amsterdam University Press, p. 73
- LAKA: Summary of 2009 events, incl. official reporting (in Dutch)
- Chalk River Laboratories, a nuclear reactor in Ontario that produces North Americas supply of isotopes for nuclear medicine