Like all man-made structures, nuclear facilities are vulnerable to seismic events. As the 2011 Fukushima nuclear disaster showed, even modern nuclear plants risk catastrophic failure when faced with a major earthquake. Although the frequency of such events is low, the consequences to the environment, economy and human health are high. As at Fukushima, the natural risks are compounded by inadequate preparation, structural weaknesses and inaccurate monitoring systems.
It is therefore imperative that nuclear sites are fitted with the best seismic monitoring and protection systems. These provide early warning of abnormal seismic activity and allow for safety procedures to be implemented in good time – which may include the shutting down of reactors and evacuation of staff and assets. A seismic monitoring system includes the protection and recording equipment designed to meet stringent safety requirements to manage earthquake risk. Given the variations across the industry, and different risk levels at installations around the world, bespoke solutions are required. Here is a quick guide.
Natural catastrophes are frequently unpredictable in terms of their timing, but their effects are calculable. The nuclear power generation industry, oil & gas sector, and military/defence sectors are particularly vulnerable to earthquakes. When dealing with nuclear materials, ordinance or volatile substances, the consequences of earthquake damage could be serious and far reaching.
In order to minimise the hazard, therefore, effective seismic monitoring and detection systems need to be in place. In recent years, these have evolved from early warning systems to complex seismic protection solutions that incorporate automatic safe shutdown with accurate recording and analysis. The purpose is to continually monitor the background vibrations that could indicate increased seismic activity. This allows structural safeguards and emergency procedures to be put in place to ensure the safety of buildings, materials, personnel and assets if an earthquake is suspected, as well as predicting the frequency, severity and potential impact of seismic activity in the area.
The risk of damage to a plant from an earthquake is raised considerably by structural factors. Vibrations from seismic events – even at a distance – can undermine the balance and integrity of machinery and buildings. However, this risk can be managed with the right infrastructure and monitoring systems in place. If highly sensitive and reliable monitoring solutions are implemented, proactive maintenance can be employed to enhance stability and minimise risk e.g. by not allowing damage to accumulate from minor seismic events, thus increasing vulnerability to larger, unexpected earthquakes.
Traditional solutions, such as manual monitoring and Micro-Electro-Mechanical Systems (MEMS), have a poor track record in terms of accuracy and early detection. These shortcomings can be resolved by integrating remote sensors into turbines and similar vulnerable structures. As a fundamental part of the overall design, seismic monitoring solutions therefore offer an advanced level of safeguarding.
Ongoing records and analysis of seismic activity and background vibrations is an on-going safety strategy for nuclear sites. The data provides engineers with a real-time overview of the risk level, meaning that issues can be identified and precautions implemented before they become serious hazards.
Additionally, data analysis can identify patterns in seismic activity over time. This means that predictive maintenance can be scheduled with enhanced accuracy and minimal costs and downtime. The cumulative effects of the benefits are greater control over the health of the plant, increased productivity and efficiency, and rigorous safety compliance.
Sensonics is the leading supplier of seismic protection and recording equipment used for monitoring critical nuclear infrastructure. For more information, get in touch with our technical sales team on sales@sensonics.co.uk.
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