Systems for nuclear facilities

1. Digital instrumentation for measuring neutron flux

Our proprietary digital instrumentation designed to measure neutron flux has successfully passed the exacting process of HW qualification. The performance tests proved the system´s capability of working reliably even during earthquakes. We have got to grips the problem of electromagnetic interference experienced in metering very low currents - the test of expedited thermal aging  proved no less than 15 years of service life. As a separate process, software was programmed following special methodology - consequently, it is qualified to perform safety function in nuclear facilities.

Our instrumentation sets can measure neutron flux generated by individual impulses, i.e. by flyby neutrons excited during the reactor start-up. This capability reaches up to the thermal power of
2 GW as attributable to special impulses encountered, for example, on the TRIGA reactors. The methods of measurement are varied: impulse, current and the Campbell method. The neutron flux density is compared with set limits, and in case the permissible values are exceeded, the system immediately extends a command to shut the reactor down.

The instrumentation provides the reactor operators with an abundance of information about the reactor´s condition that was not provided by the obsolete analog devices. The operators feel more comfortable and may activate the reactor´s automated controller to manage its output power and store the measured data.

2. Accident sequence - SCRAM systems - analog classic in a new guise

Redundant safety relay system receives signals from channels that measure neutron flux and from the Instrumentation & Control system. If any value is missing or outside the permissible limits, the system will uncompromisingly switch off the magnets of rods whose fall will scram the reactor. Consequently, a reactor failure, if any, will shut the reactor down in a safe manner.