Control system for a small fission reactor

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:865757

Burelbach, James P ^[1]; Kann, William J ^[2]; Saiveau, James G ^[3]

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1. Glen Ellyn, IL
2. Park Ridge, IL
3. Hickory Hills, IL

A system for controlling the reactivity of a small fission reactor includes an elongated, flexible hollow tube in the general form of a helical coiled spring axially positioned around and outside of the reactor vessel in an annular space between the reactor vessel and a surrounding cylindrical-shaped neutron reflector. A neutron absorbing material is provided within the hollow tube with the rate of the reaction controlled by the extension and compression of the hollow tube, e.g., extension of the tube increases reactivity while its compression reduces reactivity, in varying the amount of neutron absorbing material disposed between the reactor vessel and the neutron reflector. Conventional mechanical displacement means may be employed to control the coil density of the hollow tube as desired. In another embodiment, a plurality of flexible hollow tubes each containing a neutron absorber are positioned adjacent to one another in spaced relation around the periphery of the reactor vessel and inside the outer neutron reflector with reactivity controlled by the extension and compression of all or some of the coiled hollow tubes. Yet another embodiment of the invention envisions the neutron reflector in the form of an expandable coil spring positioned in an annular space between the reactor vessel and an outer neutron absorbing structure for controlling the neutron flux reflected back into the reactor vessel.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• DOE Contract Number: W-31109-ENG-38
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4568515
• OSTI ID: 865757
• Country of Publication: United States
• Language: English

Related Subjects

control
fission
reactor
controlling
reactivity
elongated
flexible
hollow
tube
form
helical
coiled
spring
axially
positioned
outside
vessel
annular
space
surrounding
cylindrical-shaped
neutron
reflector
absorbing
material
provided
rate
reaction
controlled
extension
compression
increases
reduces
varying
amount
disposed
conventional
mechanical
displacement
means
employed
coil
density
desired
embodiment
plurality
tubes
containing
absorber
adjacent
spaced
relation
periphery
inside
outer
envisions
expandable
structure
flux
reflected
hollow tube
spaced relation
fission reactor
neutron absorber
absorbing material
reactor vessel
neutron flux
material disposed
positioned adjacent
neutron absorbing
annular space
helical coil
reactivity control
coil spring
mechanical displacement
sorbing material
/376/976/