Probabilistic Safety Assessment (PSA)

RiskSpectrum is used for maintaining safe and efficient operations for operators in the most safety-critical industries of all - the nuclear industry. 

You can model, analyse, monitor and manage risk with RiskSpectrum. The three main tool are, from the top down in the image to the right:

  • RiskSpectrum ModelBuilder
  • RiskSpectrum PSA
  • RiskSpectrum RiskWatcher

RiskSpectrum ModelBuilder is used for creating a digital twin of your installation. With this information, RiskSpectrum ModelBuilder can automatically create Fault Trees for export to RiskSpectrum PSA. 

In RiskSpectrum PSA you can build event trees to simulate different scenarios and connect them to the fault trees generated by RiskSpectrum ModelBuilder. RiskSpectrum PSA satisfies the nuclear industry’s requirements for PSA Level 1 and level 2. It is designed with special features to cover internal, area (fire and flooding) and external events like seismic shocks.

The complete model in RiskSpectrum PSA can now be transferred to RiskSpectrum RiskWatcher. In the RiskSpectrum RiskWatcher interface operators, planners and manager can assess risk given the current configuration and for planned configurations, e.g. outages. 





In classical PSA, fault tree (FT) and event tree (ET) modelling is performed in e.g. RiskSpectrum PSA. Although such models are well understood by PSA specialists, they have low accessibility for third parties not familiar with the detailed fault tree logic.

This makes it difficult to perform independent verification and validation (V&V) reviews of the model, which is often performed based mainly on the results. This low accessibility also makes it difficult to explain and justify the results of the PSA to third parties such as plant management or regulatory bodies

The application of RiskSpectrum ModelBuilder (RSMB) offers high grade of consistency in PSA studies; the modelling assumptions are systematic and traceable, and a higher grade of homogeneity among the system models is achieved. Also, once the PSA model is built using the RSMB tool, a rapid, efficient, and systematic model update potential is ensured for the future.

Read the whole article "Model Based Safety Assessment for effective and efficient risk management" in RiskSpectrum Magazine by Dr. Dusko Kancev, PSA Specialist, NPP Gösgen-Däniken, Switzerland and Dr. Gerben Dirksen, Senior Advisor for Nuclear Safety at Framatome, Germany.

Click on the image to the right to download a copy of RiskSpectrum Magazine and flip to page 14 to read about the most recent development of RiskSpectrum PSA. 

This tool has been developed since the beginning of the 1990:ties and today includes the full set of tools you need for to editing, debuging, testing and deploying a full scale PSA model.

In an article in RiskSpectrum Magazine, the details of an implementation at Qinshan ll and Tianwan NPPs for automatic update of plant operations and planning is explained. 

Since the publication of the article, the Chinese regulator has issued a Configuration Risk Management policy that provides a regulatory framework for quantitative risk monitoring during operation and maintenance.

Click on the image on the right to read the full article in RiskSpectrum Magazine

Preventing trip at Qinshan  Nuclear Power Plant

RiskWatcher trip monitor has been installed and implemented at 9 nuclear units at Qinshan nuclear installations. ‘Tripping’ the reactor is the terminology applied to the risk of an automatic shut-down of the plant.

The RiskWatcher trip monitor tool allows operators to:

  • Assess the online risk of reactor or turbine trip (loss of production).
  • Assess the offline (planning) risk of reactor or turbine trip (for assessment of maintenance and test activities).
  • Identify the critical components, or so-call Single Point Vonerability (SPV), whose single failure will lead to reactor or turbine trip
  • Evaluate qualitatively the status of key system/functions