US 12,456,557 B2 · Adjusting wait time between burn cycles or merging burn cycles

Abstract

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

Claims14

Dependent claims

A nuclear thermal propulsion system, comprising:

a nuclear reactor core including:
an array of fuel elements;
and
a propellant supply passage to flow a propellant;
a burn cycle controller to enable reactivity control of the nuclear reactor core and configured to:
determine:
(i) an amount of xenon build-up in the nuclear reactor core after an initial burn cycle, and (ii) a depletion time necessary to reduce the xenon build-up to a sufficient level during a subsequent burn cycle;
and
responsive to determining (i) the amount of xenon build-up in the nuclear reactor core after the initial burn cycle, and (ii) the depletion time necessary to reduce the xenon build-up to the sufficient level during the subsequent burn cycle, control burn cycles by:
adjusting at least one of:
(a) a burn cycle time length, (b) a number of burn cycles, or (c) wait times between burn cycles;
or
merging burn cycles.

10 more elements

Dependencies are inferred from the claim text.

Adjusting wait time between burn cycles or merging burn cycles

Life of this patent

Adjusting wait time between burn cycles or merging burn cycles

Life of this patent

Abstract

Claims14