A pressurized water nuclear reactor includes a once through steam generator disposed in a generally cylindrical pressure vessel and a divider plate spaced apart from the open end of a central riser. In the information communication system, the target information from the storage medium is inputted into the analyzer through the information processor. The restorative signal and the frequency correction signal are provided to the converter to compensate for inter-symbol interference. Each execution can consume an amount of power under the changed operating environment in the device.