EDF Rod Drop Monitoring

Rod Drop Regulatory Requirements

The recording of control rod drop times is a regulatory requirement of the nuclear site license.

ITI Group’s Rod Drop Monitoring system uses commercially off-the-shelf hardware and software, can be easily adapted to the requirements of any nuclear power station, overcomes the spares issues with obsolete equipment, and has a proven install base.

System benefits

Automatic data processing

The previous system involved laborious manual intervention to process & print the data charts. All data processing & chart printing is fully automated in the new system.

Calibration facility

The system includes a calibration spreadsheet HMI to allow operators to calibrate the rod height data against actual rod height (conversion of pulse inputs into analogue rod height).

Resolution

The system provides increased resolution & extended windows for the data charts. This enhances the data quality for ‘post trip’ analysis work.

Chart Display

Multi-line detailed charts showing 2secs before trip and 28secs afterwards.

Security

User access is based on an ‘administrator controlled’ user privileges set-up.

File management and archiving facility

Offering user-friendly off-line storage of trip & calibration data.

Real-time rod height display & slack switch status

Automatic collection of ‘reactor trip’ data.

Data window requirements:

• Data window to start at 2 sec. pre trip condition.
• Data window to extend for 28 sec. post trip condition
• Data collection to include all 121 rods.
• Data resolution: 20 msec.

Data visualised through chart display & printouts

Rod height versus time.

System calculates intermediate values

Alarm system

Including reactor trip, power supply failure & system health status