On-Line Gamma Irradiation Test of High Speed Fiber Optic Transceiver

The field data communication based on the fiber optics is considered for application in nuclear environments. The nuclear facilities, including nuclear power plants, high radioactivity waste disposals, reprocessing plants and thermonuclear fusion installations can benefit from the unique advantages of the fiber optic data communication for the smart field instruments and controls. A major problem which arises when dealing with fiber optic data communication in these environments is the presence of high dose-rate gamma irradiation fields. Radioactive constraints for the DBA(design basis accident) qualification of the RTD transmitter installed in the inside of the RCS pump are typically on the order of 4kGy/h with total doses up to 10kGy. In order to use fiber optic communication system as an ad-hoc sensor data link in the vicinity of the reactor area of the nuclear power plant, the robust survivability of these system in such intense gamma radiation fields therefore needs to be assessed. We have conducted high dose-rate (up to 1.5kGy) gamma irradiation experiments on a COTS fiber-optic transceiver module for the USB2.0 interface data link. In this paper we describe the evolution of its basic characteristics with high dose-rate gamma irradiation and shortly explain the observed phenomena