PNNL

Abstract

Proof-of-principle test results are presented for a nuclear-to-electric power generation technique utilizing closed-cycle fuel cell operation. The approach being developed is to first use the decay energy of a radioisotope to generate H2 and O2 from water, and then to utilize these species in a fuel cell to generate electricity. The principle of operation allows the device to regenerate its own reactants and operate continuously as a closed system for as long as the primary source of power, namely the radioisotope, is active. With micro engineering and fabrication techniques available today, a miniaturized integrated package of 1 cm3 in size and producing power in the 10 mW range appears feasible in a mature design. Smaller devices producing less power would also be possible. For this project, a unique fuel cell capable of utilizing mixed reactants at room temperature has been developed. The efficiency of this early fuel cell design falls in the range between 10 and 20%. Measured power output from a radioisotope fueled test cell approached 0.45 mW for several hours with a radiation leakage rate estimated at 490 mrem yr-1.