The efficiency of ozone synthesis from oxygen in a chemonuclear reactor is estimated as a function of temperature, ozone concentration, and dose rate from extrapolation of previous experimental results obtained with 60Co gamma irradiation. The extrapolations give G(O3) ≳ 9 for conditions closely approximating those cited by economic analysis as potentially interesting. Fission fragment irradiation experiments give G(O3) ≈ 6 at T = ×78°C for [O3J up to 0.45 vol%, in reasonable agreement with the extrapolations.