Radiation induced electromotive force in mineral insulated cable under reactor irradiation

A radiation induced electromotive force (RIEMF) was measured in mineral insulated cables (MI-cables) under fission reactor irradiation. A negative electromotive force of about 10 V was generated in the center lead by the reactor irradiation. The RIEMF increased with increasing irradiation dose with about -14 V measured under the reactor full power irradiation at 573 K with a total dose of 1.1 x 10(10) Gy ionizing irradiation and 1.1 x 10(24) n/m(2) fast neutron irradiation. The measured voltage of the RIEMF was found to depend linearly on the reciprocal temperature. The observed RIEMF was a so-called current driven source and the measured current was linearly dependent on the reactor power and was about 50 nA for the 0.7 m long MI-cables at 573 K. Under full power, irradiation conditions were 6 W/g of a gamma flux (6 x 10(3) Gy/s ionizing dose rate) for iron and 5 x 10(17) n/m(2)s and 1.1 x 10(18) n/m(2)s fast and thermal neutron fluxes, respectively.