For a long time, it was not very relevant for patients and nuclear medicine specialists to know where the medical isotopes came from. After all, they were always available. However, unexpected production limitations changed this since 2008. The majority of all medical isotopes that healthcare professionals use worldwide is produced in six reactors. Within 15 years 75% of the production capacity needs to be replaced, because five of the six reactors, including the HFR in Petten, are older than 45 years. The older a nuclear reactor is, the greater the risk of production suddenly coming to a standstill and the bigger the risk that patients will not get a diagnosis or treatment. That is why the PALLAS-reactor is necessary – to secure the worldwide supply of medical isotopes.