Core monitoring systems in prototype fast breeder reactor

Full text: The core monitoring systems primarily comprise of global neutron flux monitoring, failed fuel detection and location, fuel subassembly temperature monitoring and core flow monitoring. High temperature fission chambers are provided at in-vessel locations for monitoring neutron flux. Failed fuel detection and location is done by monitoring the cover gas for fission gases and primary sodium for delayed neutrons. Chromel-Alumel thermocouples (TC) are provided at the outlets of the fuel subassemblies and core inlet for core temperature monitoring. For core flow monitoring, permanent magnet flowmeter and probe type Eddy current flowmeters are provided at the primary sodium pump discharge. Signals of the core monitoring detectors are used to initiate SCRAM to protect the reactor from various postulated initiating events