Self-actuating reactor shutdown system

Patent · Thu Dec 31 23:00:00 EST 1987

OSTI ID:866717

Barrus, Donald M ^[1]; Brummond, Willian A ^[2]; Peterson, Leslie F ^[3]

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1. San Jose, CA
2. Livermore, CA
3. Danville, CA

A control system for the automatic or self-actuated shutdown or "scram" of a nuclear reactor. The system is capable of initiating scram insertion by a signal from the plant protection system or by independent action directly sensing reactor conditions of low-flow or over-power. Self-actuation due to a loss of reactor coolant flow results from a decrease of pressure differential between the upper and lower ends of an absorber element. When the force due to this differential falls below the weight of the element, the element will fall by gravitational force to scram the reactor. Self-actuation due to high neutron flux is accomplished via a valve controlled by an electromagnet and a thermionic diode. In a reactor over-power, the diode will be heated to a change of state causing the electromagnet to be shorted thereby actuating the valve which provides the changed flow and pressure conditions required for scramming the absorber element.

• Research Organization: GENERAL ELECTRIC CO
• DOE Contract Number: AT03-76SF71032
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4770845
• OSTI ID: 866717
• Country of Publication: United States
• Language: English

Related Subjects

/376/310/313/337/374/976/
absorber
absorber element
accomplished
action
actuated shutdown
actuating
automatic
below
capable
causing
change
changed
conditions
conditions required
control
controlled
coolant
coolant flow
decrease
differential
diode
directly
directly sensing
due
electromagnet
element
fall
falls
falls below
flow
flux
force
gravitational
gravitational force
heated
independent
initiating
insertion
loss
low-flow
neutron
neutron flux
nuclear
nuclear reactor
over-power
plant
pressure
pressure conditions
pressure differential
protection
provides
reactor
reactor conditions
reactor coolant
reactor shutdown
required
results
scram
scramming
self-actuated
self-actuated shutdown
self-actuating
self-actuating reactor
self-actuation
sensing
shorted
shutdown
signal
thermionic
upper
valve
valve control
via
weight