As we wrote recently, smaller-scale nuclear reactors are increasingly popular for a variety of reasons — from cost to flexibility. The following is an assessment or why more and more companies and regions are expressing interest in Small Modular Reactors (SMRs).
Modularity: Lower Upfront Capital Costs
The price to construct a conventional nuclear power plant has risen so high that private investors are no longer interested in funding new nuclear projects. SMRs offer a cheaper alternative; they are characterized by compact designs that can be factory-fabricated, module by module, and then transported to a nuclear plant site for final assembly. By exploiting economies of scale, factory-fabrication reduces construction costs and is more efficient than on-site construction by as much as 8:1 in terms of building time.
The modularity of SMRs also allows for incremental capacity expansion of power plants, limiting the risk of overstepping demand. Once the first module comes online it can begin generating positive cash flows to fund the construction of subsequent modules. This flexible funding profile creates options to match demand growth while lowering upfront capital costs and reducing the investment risks compared to conventional nuclear plants.
SMRs provide an emission-free opportunity to address the challenges of energy security and rising demand for electricity in developing countries. SMRs offer an attractive power option to energy-starved countries and small, remote, growing communities that cannot afford and don’t require a full-scale plant. While conventional light water reactors typically require a great deal of water for cooling and must be located near a substantial water source such as a coastline or river, SMRs boast flexible designs that can be cooled by air, gas, metals or salt. SMRs can thus be placed in remote, inland locations where a conventional reactor would be impossible to sustain.
SMRs’ modularity and flexible designs also make them an attractive, emission-free option for the replacement of maturing fossil plants and for providing water purification and process heat to industrial applications in a broad range of locations.
Safety: Simple & Passive Features
The enhanced safety and security features of SMRs are the product of decades of operational experience and research. SMRs have fewer complex components and rely on simpler safety systems than do conventional reactors. SMR designs incorporate passive safety features that rely on the forces of physics rather than mechanical or human interference to keep the reactor safe.For instance, SMRs use gravity to circulate cooling water in the event of electrical power loss, and use convection and conduction to remove excess heat to prevent a reactor meltdown.
These inherent and natural safety features allow SMRs to self-regulate without external electricity for a potentially indefinite amount of time. In addition, many SMRs have fully integrated designs with the control rod mechanisms, pressurizer and steam generator all contained within the reactor vessel without any openings for potential coolant leakages.
Security: Waste Reduction and Nonproliferation
SMRs can provide nonproliferation benefits to the international community. They can be fabricated, fueled and sealed in a factory before transport to a plant site. At the end of the reactor’s life cycle, the modules can be returned to the factory for defueling. This, coupled with the longer refueling cycles (up to 30 years), minimizes the handling and thus the vulnerability of nuclear material. Most SMRs are installed below ground, and are therefore less vulnerable to attacks and natural hazards.
SMRs also offer a solution to the nuclear waste issue. Some SMRs can actually use the nuclear waste generated by today’s conventional reactors as fuel. Others can consume the material from old nuclear weapons as fuel. Some SMRs do not even need uranium and can operate on thorium instead. Thorium happens to be incredibly abundant, easy to process for fuel and completely useless for making weapons.
>>Read previous Forum on Energy coverage and analysis of SMRs: