Plans for a successor to the research reactor were already underway in 1978; the first foundations were laid in 1996. Three years later, construction was in full swing and, by 2001, had progressed so far that the reactor could be put into operation. An operating license had been applied for but not yet granted, since at that juncture no further nuclear facility had been approved for political reasons, regardless of whether the purpose was to generate electricity or – as in the case of the FRM II – for neutron research. Scientists and engineers took advantage of the long count-down to develop and install new instruments. The Atomic-Egg had served almost exclusively for research in the fields of nuclear and particle physics and the irradiation of tumor patients. The FRM II was designed to allow for much more comprehensive research, development and treatment and required further and more modern instruments to fulfill its potential. After numerous delays, the operating license was finally issued so that the FRM II was able to come up with the first neutrons on 2 March 2004.
On account of all this, the FRM is up to meeting challenges of all sorts, such as an airplane crash, lightning, floods, earthquakes and explosions, and has a sophisticated multiple safety system. It might now be justifiably described as the world's most advanced, most powerful and safest nuclear facility (see "Safety First").
From its very inception, the FRM II has proved to be an extremely powerful magnet for scientists from around the world. Therefore, in 2007, the neutron guide hall east was opened, creating additional space for further instruments. Most of the instruments that are connected to the neutron guide belong to their partner institutions that joined the Heinz Maier-Leibnitz Center in 2011, to allow about 1,000 researchers per year access to the now almost 30 instruments.
In March 2014, on the occasion of the 10th anniversary of the FRM II’s operation, a “Festschrift” (in German only) with a brief outline of the construction and development was published.