SMR applications for Ground Fault detection

The NRC refers to non-light water reactor (non-LWR) designs and small modular light water reactors (SMRs) as advanced reactors. These reactors incorporate innovative technologies compared to existing operating reactors, such as passive safety features, alternative fuel or coolant types, or smaller reactor sizes. While non-LWRs use distinct technologies and materials, SMRs are a subset of light water reactors that are designed to be more compact, scalable, and potentially safer, with many sharing features like passive safety systems and advanced engineering designs.

Nuclear fusion is the process by which two atomic nuclei—the central cores of atoms, made up of protons and neutrons—combine to form a heavier nucleus, releasing energy. This reaction occurs naturally in the sun and stars, and technologies to replicate it for energy applications are currently in development. Unlike nuclear fission, which splits atoms, fusion does not produce long-lived radioactive waste. While fusion technology is still in development, the Nuclear Regulatory Commission (NRC) is engaging with stakeholders to understand the regulatory considerations associated with potential future fusion facilities.

Unlike traditional nuclear power, which relies on fission reactors to split atoms, nuclear fusion can be generated in machines designed to replicate the high-temperature and high-pressure conditions found in the sun. These machines, such as tokamaks and stellarators, use powerful magnetic fields or lasers to heat and confine hydrogen isotopes until they fuse, releasing energy. Creating and sustaining the high temperature and pressure conditions for fusion on Earth has been a major technological challenge since the first controlled fusion in 1958, but significant progress has been made in recent decades. While often referred to as "fusion reactors," fusion machines are not reactors in the sense normally associated with nuclear power because they do not rely on a self-sustaining chain reaction to produce energy. Instead, fusion machines require a continuous external energy input to maintain the conditions necessary for fusion to occur.

The high amount of energy needed to power these magnetic fields for both radio frequency (rf) and power circuitry to power circuitry for the fusion tokomaks requires both elevated levels of predictive monitoring and electrical safety.  Medium voltage power circuits are effectively “offline monitored” using Insulation Monitoring devices (IMDs) in an ungrounded state prior to energizing the fusion MV power circuits.  In addition, the communications side must also be effectively monitored to insure that no ground faults are present to avoid imperfection in communications also using IMD’s.

Once the power system is safely energized the power to the magnets/ tokomak array will be in a grounded state and must be then monitored via residual current monitors to insure that no ground faults are present during the process.

Bender has a full range of Insulation Monitoring devices (IMD) and residual current monitoring (RCM) devices  for SMR and Fusion applications. 

This adds to Bender’s legacy IMD/ EDS fault location systems that are widely used globally in legacy Fission plants to provide increased levels of predictivity and safe uptime where time to diagnose is also dramatically decreased since fault detection and location is performed in real time as a predictive tool.