Magnetic latch trigger for inherent shutdown assembly
AssigneeThe United States of America as represented by the United States Energy Research and Development Administration
InventorEdmund S. Sowa
Life of this patent
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Abstract
An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core.
Claims6
In a nuclear reactor, an inherent shutdown assembly for releasing a neutron absorber into the core region of the reactor with the density of neutron flux of the core region at a critical level, comprising:
- support means adjacent the core region capable of supporting an object coupled thereto, a neutron absorber, a fissionable material exposed to the neutron flux of the core region so that as the density of said flux varies the temperature of said fissionable material varies proportionally, and a magnetic latch including a magnet and a ferromagnetic link in contact with said fissionable material so that the temperature of said link varies proportionally with the temperature of said fissionable material and thereby with the density of said flux, said latch being coupled to said support means and said absorber so that with the density of neutron flux below the critical level said link is attracted to said magnet to form a completed magnetic circuit of sufficient attractive force between said link and said magnet to couple the absorber to said support means whereby the absorber is held in a position adjacent the core region, and so that with the density of neutron flux at least equal to the critical level the magnetic permeability of said link being of such value that the attractive force between said link and said magnet is insufficient to couple said absorber to said support thereby allowing said absorber to enter said core region.
Dependencies are inferred from the claim text.