The necessity of development of the remote monitoring system of the radiation situation based on fiber-optic sensors for pools of nuclear power plants is substantiated. New method of building of communication line with fiber-optic sensor for controlling exposure dose of radioactive radiation in the large range of changes (several orders of magnitude) in remote mode is suggested. The design of sensor to provide measurements for long distance (more than 10 km from the location of the monitoring center) is developed. Functional capabilities of the fiber-optic sensor are identified. Experimental results are presented.