Extreme Temperature Radiation Tolerant Instrumentation for Nuclear Thermal Propulsion Engines

The United States' National Space Policy specifies that NASA shall begin sending crewed missions beyond the moon by 2025, and sending crewed missions to Mars by mid-2030s. In order to accomplish these tasks, nuclear thermal rockets have been identified as the propulsion system of choice; the technology proposed here would find extensive application in the field of nuclear powered space flight. The smart neutron sensor can enable increased safety, efficiency, and control for nuclear thermal propulsion engines. Additionally, this technology will be applicable for fission surface power systems. These power systems utilize nuclear fission to generate electricity, and are intended for use in environments where solar power is not a viable option, such as a Martian outpost, or where the weight of solar cells would greatly increase the cost of a surface power station, such as a lunar outpost. The neutron smart sensor can again find application in these harsh environments, where their installation could again address the safety and control concerns for the nuclear power plant.

In nuclear power plants, a neutron monitoring system is used to monitor power generation and, for the safety function of the neutron monitoring system, to provide trip signals to the reactor protection system to initiate reactor scram under an excessive neutron flux increase condition or neutron flux fast rising condition. The system also provides power information for the operation and control of the reactor to the plant process computer system. Newer nuclear power plant designs have increasing reactor temperatures and neutron flux rates; for example, the Generation IV type reactors contain the Very-High Temperature Reactor (VHTR), which is graphite moderated and helium cooled. The reactor outlet temperature on such designs may approach 1000 degC, as soon as the appropriate materials technology has been developed to accommodate the increasingly harsh environment. Such high temperature reactors will need to have a neutron monitoring system as well, and the DND smart sensor system can find many applications here, replacing current lower temperature neutron sensing solutions. More »