According to Wikipedia (German) the Wendelstein 7-X already did 150 mega joules of "sustained fusion" [1]. So how is this record breaking?
Until recently no MCF device on Earth was nuclear. Today's headline is the return of JET's nuclear operations.
There are dozens of MCF machines operating right now and only one is nuclear. That means Q as a metric is only useful for one machine. Something to think about when people toss around Q-related rhetoric around here.
Google translation of the beginning of the Strahlenschutzaspekte (radiation protection concerns) section from the German Wikipedia article [1]. There will only be a tiny bit of accidental fusion.
Wendelstein 7-X only examines plasmas made of hydrogen (H) or deuterium (D), so it does not use a mixture of deuterium and tritium, as is necessary for later fusion reactors. The omission of this reduces the release of neutrons and enables access to the facility and the surrounding instruments immediately after the end of each experiment. This facilitates modifications for subsequent experiments. During operation, however, access to the torus hall is generally not possible for safety reasons (danger of voltage flashovers, stored energy in the magnetic fields).
Hydrogen is provided as the working gas for normal operation. In addition, experiments with deuterium are to be carried out in order to extrapolate the properties of a plasma mixture of deuterium and tritium. Fusion reactions between deuterium nuclei, in which neutrons are released, can occur to a small extent. To shield them, the torus hall is surrounded by a 1.8 m thick wall made of borated concrete.
[1] https://de.wikipedia.org/wiki/Wendelstein_7-X#Strahlenschutz...