This is an undercritical reactor, which cannot sustain any chain reaction.
From the sciencedaily.com
The malfunctioning Japanese reactor set off a chain reaction that turned his world upside down.
From the time.com
The overloaded FTL reactor will cause a chain reaction in the sun.
From the en.wikipedia.org
To shut down a nuclear reactor, you need to stop the chain reaction.
From the nzherald.co.nz
They also release additional neutrons, which in turn smash neighboring atoms and thus continue the heat-producing chain reaction inside the reactor.
From the time.com
In a nuclear reactor, such a chain reaction is slowed and controlled by a neutron poison, absorbing some of the free neutrons.
From the en.wikipedia.org
For starting a nuclear chain reaction in a reactor, the only important isotope is uranium-235, which accounts for JUST 7 out of 1000 atoms in the mined product.
From the sciencedaily.com
Damage the reactor cells and you'll trigger a chain reaction.
From the en.wikipedia.org
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction.