At a time when cutting investment and operational costs is a major target of the nuclear energy sector, engineers and researchers from all parts of the world are on a quest to find the most viable solutions. We, too, decided to look into this problem – to approach it from the perspective of valves. Can these critical components help nuclear power plants save costs?
Recent reports suggest that commercial-grade valves have now reached the same degree of quality and reliability as nuclear-grade valves. Practically speaking, these reports imply it is safe for highly demanding facilities, such as nuclear plants, to replace their highly specific, purpose-made valves with serially produced conventional ones.
Why would a facility want to replace its specialized valves with alternative ones? One big reason would be to save costs. Yet never, ever at the expense of safety, which is at the very core of nuclear power production.
This blog is a summary of a master’s thesis done in collaboration with Neles to investigate just that – the viability of replacing nuclear-grade valves with commercial-grade ones in the Nuclear Safety Class 3 (SC3).
Emergency shutdown valves: challenges and requirements
For this study, performance and safety requirements for the more expensive nuclear-grade on-off shutdown valves in SC3 were compared with the requirements for a similar class of valve, such as Emergency Shutdown (ESD) valves, used in the fuel and petrochemical industries.
Typical challenges for fuel and oil ESD valves include:
- Tight shutoff
- Erosive, corrosive, sticky and toxic fluids
- Strict quality and emission requirements
- Fire safety
- Partial stroke testing during normal operation
- Safety factors for valve and actuator sizing
- Outstanding durability and reliability
