Reactor shutdown NPP Ringhals

On December 29, reactor 3 at the Swedish nuclear power plant Ringhals experienced a rapid shutdown for unknown reasons, causing a significant event on the electricity grid. Automatic protection and other measures worked as intended and a major outage was avoided, but the question remains – will the strained Swedish grid withstand such events in the future?

According to information received from our customers, the stop was caused by: Frequency Emergency power input 5 on Konti-Skan Ringhals 3 tripping with 1100 MW for unknown reason. EPC intervention input 5 at Konti-Skan. Failed start of Lahall B1 and B2.

With Unipower’s PQ Secure system, the Continuous Scan (CS) module allows you to study the entire process before, during and after the event in detail. The module is based on continuous high-speed recording of all information, is in no need of a set-up, and automatically captures all events in the power network. Supporting data for investigations, ranging from RMS values to waveforms, are easily produced.

Frekvens och dfdt under händelsen

Image 1: Frequency and dfdt during the event

Spänning påverkas hela vägen ner till lågspänningsnätet

Image 2: Voltage affected all the way down to the low voltage grid

The CS module can also produce waveform information as well as information on harmonics, imbalance, power, etc.

For more information, please contact Unipower.