The change in nuclear fission rate caused by voids within a reactor
In nuclear engineering, the void coefficient (more properly called void coefficient of reactivity) is a number that can be used to estimate how much the reactivity of a nuclear reactor changes as voids (typically steam bubbles) form in the reactor moderator or coolant. Net reactivity in a reactor depends on several factors, one of which is the void coefficient. Reactors in which either the moderator or the coolant is a liquid will typically have a void coefficient which is either negative (if the reactor is under-moderated) or positive (if the reactor is over-moderated). Reactors in which neither the moderator nor the coolant is a liquid (e.g., a graphite-moderated, gas-cooled reactor) will have a zero void coefficient. It is unclear how the definition of "void" coefficient applies to reactors in which the moderator/coolant is neither liquid nor gas (supercritical water reactor).
In nuclear engineering, the voidcoefficient (more properly called voidcoefficient of reactivity) is a number that can be used to estimate how much the...
reactor design had several shortcomings, such as the large positive voidcoefficient, the 'positive scram effect' of the control rods and instability at...
": 24 The reactor had a dangerously large positive voidcoefficient of reactivity. The voidcoefficient is a measurement of how a reactor responds to increased...
moulding VoID or Vocabulary of Interlinked Datasets, an RDF vocabulary to enable the discovery and use of linked data sets Voidcoefficient, the change...
problem in reactors that have a positive voidcoefficient of reactivity, a positive temperature coefficient, are overmoderated, or can trap excess quantities...
Nuclear reactor response properties such as Temperature coefficient of reactivity and Voidcoefficient of reactivity usually refer to the thermodynamic and...
that time had a positive voidcoefficient of reactivity at low power levels. This meant that the formation of steam bubbles (voids) from boiling cooling...
the moderator is also lost and the reaction will stop. This negative voidcoefficient is an important safety feature of these reactors. In CANDU the moderator...
can provide positive or negative feedback (a positive or negative voidcoefficient), depending on whether the reactor is under- or over-moderated. Intermediate-energy...
example, power plants licensed in the United States require a negative voidcoefficient of reactivity (this means that if coolant is removed from the reactor...
perpendicular to the current. It was discovered by Edwin Hall in 1879. The Hall coefficient is defined as the ratio of the induced electric field to the product...
media some defects in the RBMK reactor design such as the positive voidcoefficient, as well as problems with operator training. Some details were censored...
suppression of voids formed at the boundary interface in various kinds of alloy to metal bonding. These are referred to as Kirkendall voids. The Kirkendall...
and compensating for loss of cooling, a condition known as negative voidcoefficient. Later versions of the reactors are encased in massive steel reactor...
California, Berkeley in 1942. Subcritical reactor Thermal neutron Voidcoefficient Tucker, Todd (2009). Atomic America: How a Deadly Explosion and a Feared...
[clarification needed] The prototype fast breeder reactor has a negative voidcoefficient, thus ensuring a high level of passive nuclear safety. This means that...
even these comparatively low concerns, for example the IFR's positive voidcoefficient could be reduced to an acceptable level by adding technetium to the...
moderated by groundwater and, presumably, controlled by the negative voidcoefficient as the water boiled from the heat of the reaction. Uranium from the...
(being cooled with ordinary water instead) which produced the positive voidcoefficient that was one of a series of flaws in reactor design leading to the...
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume...
pressurized water reactor, a boiling water reactor has a negative voidcoefficient, that is, the neutron (and the thermal) output of the reactor decreases...
however, the reaction slowed or stopped. The reactor thus had a negative voidcoefficient of reactivity, something employed as a safety mechanism in human-made...
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