Boron has been used for many years in the nuclear industry because the Boron
10 isotope has the unique property of absorbing neutrons during nuclear
fission thus controlling the rate of the reaction and even halting the
reaction if required.  Boric Acid is the primary borate used for this
application to control the rate of reaction, but Borax Pentahydrate can also
be used as an excellent corrosion inhibitor.  And boron carbide rods that
are manufactured from boric acid are used as a primary neutron absorber.  In
the case of a nuclear emergency, the boric acid will be employed to quench a
reaction that is out of control to avoid a nuclear meltdown.