NSUF 24-4798: Reliability Assessment of Irradiated Integrated Silicon Carbide Pressure/Temperature Sensors for Lunar Fission Surface Power Reactor

NASA and DOE are developing a technology demonstration of a 40 kWe Lunar Fission Surface Power (FSP) reactor that would be precursor to future nuclear reactor on planet Mars. The primary goal is to support future long duration human habitation and scientific research on the moon and Mars. Unlike the conventional nuclear reactors, the FSP reactor is compact (fits within a 4 m diameter cylinder), unmanned, and with a prescribed 10-year operational life. These place significant technological challenges on sensors and instrumentation that must equally be compact (reduced form factor), possess multi sensing characteristics (integrated functionalities), radiation resilient, high temperature (~800 ℃) durable, and perform reliably for 10 years. The most daunting of these challenges is that failing sensors on the lunar FSP reactor do not have the luxury of maintenance or replacement. Therefore, from the standpoint of reliability and robustness, which are imperative for a successful FSP reactor demonstration, such enabling reliable sensor technologies do not currently exist for deployment. That is why DOE and NASA are developing new sensor technologies that must have robust and reliable attributes when operating remotely in terrestrial micro reactors and lunar FSP reactor, respectively. NASA Glenn Research Center (GRC) have developed integrated silicon carbide (4H-SiC) pressure/temperature sensors with reduced form factor and operated at 800 ℃. Pressure and temperature characterizations were conducted, and the results offer promise for future FSP reactor application, thereby making it a prime candidate to simultaneously measure pressure and temperature near the reactor core. The preliminary results from a discrete SiC piezoresistive pressure sensor, including other published data provided clear evidence of the superior radiation hardness of SiC sensors over conventional silicon sensors and electronics. However, to determine the practical viability of the integrated SiC pressure/temperature sensors for the FSP reactor application (and derivatively, for micro reactors), it is imperative to quantify their long-term reliability. The experimental data generated through such campaign would, for the first time, help to understand and quantify the long-term effects of gamma and neutron irradiation on lunar based reactor sensors, and create new reliability physics of failure. This research effort will conduct reliability studies of MEMS-based SiC integrated pressure/temperature sensors at gamma and neutron irradiation levels that would lead to eventual quantification of their operational reliability toward supporting a 10-year reactor life on the moon. The study is expected to provide new knowledge into the radiation hardness of SiC under potential damage-inducing radiation, radiation-induced voltage offset shifts/drifts and hysteresis in pressure sensitivity and gauge factor (ratio of relative change in resistance to strain), metal/SiC interface degradation, local polytypic transformations, and conductivity transmutation. The results would form the foundation of a new reliability physics of radiation-induced sensor failure, from which figures of merit such as mean time before failure (MTBF) could be deduced.

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Поле	Стойност
Award Announced Date	2024-02-02T12:09:10.373
Awarded Institution	NASA Glenn Research Center
Facility Tech Lead	Raymond Cao
Irradiation Facility	Ohio State University Research Reactor
PI	Robert Okojie
PI Email	[email protected]
Project Type	RTE
RTE Number	None