Spent Fuel Monitoring with Silicon Carbide Semiconductor Neutron/Gamma Detectors

Abstract

Silicon carbide semiconductor radiation detectors have been demonstrated for neutron and gamma-ray monitoring of spent nuclear fuel. Neutrons and gamma rays were monitored simultaneously over a 2050-h period, resulting in a gamma dose of over 6000 Gy to the SiC detector. No changes in the neutron and gamma-ray sensitivity were observed as a result of the gamma-ray exposure. After the spent-fuel measurements, the absolute neutron sensitivity was determined in a standard neutron field, and the degree of gamma-ray and neutron spectrum overlap were determined through exposures in intense gamma ray fields. No overlap was observed for gamma-ray dose rates up to 100 G/h.

How can we use SiC?

“…Long-term monitoring carried out over a 2050 hour period and a total gamma-ray dose to the detector of over 6000 Gy did not induce gain drifts in the detector [20]. This is still a limited test in terms of total neutron fluence but is nevertheless encouraging for performing more extensive tests of SiC detectors in a high neutron flux environment.…”

The effects of intense gamma-irradiation on the alpha-particle response of silicon carbide semiconductor radiation detectors

“…Such severe environments can be encountered in terrestrial [8] and space [3] nuclear reactor applications as well as in spent reactor fuel monitoring applications [9,10]. Natsume et al [10] showed that the gamma and neutron response efficiencies for a SiC Schottky diode were unchanged during and following a 2050-h exposure to spent nuclear fuel resulting in an estimated 6-kGy gamma-ray exposure.…”

“…Natsume et al [10] showed that the gamma and neutron response efficiencies for a SiC Schottky diode were unchanged during and following a 2050-h exposure to spent nuclear fuel resulting in an estimated 6-kGy gamma-ray exposure. The present work indicates that the SiC detector would continue to operate for greater than 200 years in a similar spent-fuel measurement environment.…”

Effect of metal electrode on characteristics of gamma-irradiated silicon carbide detector

“…Research has demonstrated that SiC radiation detector response is highly linear for neutron and gamma rays and highly feasible for harsh high-temperature and high-radiation environments [7][8][9]. Generally neutrons are measured with a semiconductor detector with neutron convertors such as 6 Li or 10 B.…”