NuScale FAQs
The U.S. Department of Energy projects the electricity demand in the U.S. alone to increase 21% by 2040. That equates to roughly 340 GWe of new capacity.
A
Corporate Commitment
1. When was NuScale Power formed?

NuScale Power was officially incorporated in 2007. However, development of the original reactor concept was initiated in 2000 as a collaborative project with Oregon State University, the Idaho National Engineering and Environmental Laboratory, and Nexant. The original concept, designated as Multi-Application Small Light-Water Reactor” (MASLWR), was refined by OSU after the conclusion of the initial 3-year project and became the basis for the current NuScale design.

2. Who provides the financial backing for NuScale Power?

NuScale Power was originally financed by a collection of strategic partners and capital venture investors. In October 2011, Fluor Engineering became the majority investor and a key strategic partner for engineering, procurement and construction services. As of the end of 2016, Fluor has invested over $375 million in NuScale in addition to leveraging Fluor’s international resources and experience with the existing nuclear fleet.

In December 2013, the U.S. Department of Energy announced their selection of NuScale Power to receive up to $226M of matching funds to support the further development of the design and to secure a Design Certification from the U.S. Nuclear Regulatory Commission. This public-private partnership will help to accelerate the completion of the design, licensing and first-of-a-kind engineering, which will enable potential deployment of the first plant by 2026.

3. The NuScale design includes many innovations—is this intellectual property being protected?

NuScale has been actively pursuing patent protection for the many innovations contained within our design. More than 350 patents are in force or pending in 19 North American, European, or Asian countries. The number of patent filings continues to increase as innovative engineering solutions are developed throughout the plant design.

4. Is NuScale Power pursuing international customers and investors?

There is substantial international interest in small modular reactors and in the NuScale design specifically. We are actively pursuing this huge market opportunity while maintaining a priority on domestic licensing, manufacturing, and deployment opportunities.

5. Where do you expect the first NuScale plant to be built?

The first commercial 12-module NuScale power plant is planned to be built on the site of the Idaho National Laboratory. It will be owned by the Utah Associated Municipal Power Systems (UAMPS) and run by an experienced nuclear operator, Energy Northwest.

B
Enhanced Safety
1. How has safety been enhanced?

Safety is enhanced by deliberate design choices that eliminate as many potential risks as possible, reduce the likelihood of accidents, and ensure that if an accident does occur, the consequences are minimal. NuScale builds on lessons learned from the existing fleet of commercial power reactors and incorporates those lessons into the fundamental design of the NuScale plant, as well as including several new design innovations to further enhance safety.

As examples, the NuScale design eliminates many vulnerable pipes, pumps and valves from the design and replaces many engineered backup systems with features that operate automatically relying on natural phenomena such as gravity, convection and conduction. The small unit size of the reactor and the assured heat removal mechanisms provided by the steel containment vessel and large reactor pool effectively guarantee that no fuel will be damaged even after an extreme event, and therefore, no radioactivity will be released. The NuScale design also adds multiple additional design features that can reduce or delay the release of radiation in the unlikely event that fuel is damaged.

2. How do you know it will be safe?

First, by basing the NuScale design on light-water reactor technology, we are able to build on the vast global experience with this technology, including material performance, water chemistry, transient behaviors, etc. Secondly, we are conducting an extensive test program that spans the gamut from physics-based separate effects tests to full-out integral performance tests. Thirdly, our design will be thoroughly reviewed and certified by the U.S. Nuclear Regulatory Commission, which sets the world standard for defining rigorous safety requirements.

3. What is the significance of your “triple crown” announcement and how do you achieve it?

In the spring of 2013, NuScale announced a major leap forward in nuclear safety by developing a novel engineering solution that will provide an unparalleled level of safety, security, and asset protection. Specifically, the design now provides for an unlimited period of cooling of the nuclear fuel and containment without the need for: (1) operator action, (2) AC or DC power, or (3) the resupply of cooling water. It provides stable long-term nuclear core cooling and plant recovery under all design basis accident conditions and also provides severe accident mitigation for low probability beyond design basis accidents. This safety breakthrough is enabled by the incorporation of fail-safe valves into the simple, assured emergency core cooling system. Key features of this system include a high-pressure containment vessel immersed in a large pool of water and a passive emergency core cooling system that relies only on gravity-driven convection of the coolant and conduction of heat to the containment vessel surface.

4. Does the small containment structure of a NuScale module decrease safety?

Actually, the unique containment design enhances the safety of a NuScale module in several ways. First, the pressure tolerance of a vessel is inversely proportional to its diameter, so making the containment vessel physically smaller allows it to withstand a higher pressure pulse than a large vessel. The NuScale containment vessel has a design pressure that is roughly 10 times higher than traditional plants. Secondly, the smaller volume inside the containment allows us to draw a vacuum in this space, which provides effective thermal insulation to the reactor vessel. This eliminates the need for insulation material on the vessel, which has been prone to flaking and sump clogging in existing plants. The vacuum also enhanced steam condensation rates on the inside surface of the submerged containment in the case where steam is vented from the reactor vessel, which in turn provides for very effective heat removal from the primary system. Finally, the lack of oxygen inside containment greatly reduces the likelihood of forming a combustible mixture of oxygen and hydrogen during accident situations.

5. Didn’t Fukushima demonstrate that multi-module plants are too risky?

Quite the contrary. Many of the system failures that resulted in the destruction of several of the Fukushima Daiichi reactor units do not even exist in the NuScale design and our level of plant resilience is substantially higher than those at Fukushima. Regarding the implications of multi-unit plants or sites, one needs to first consider the Fukushima Daiichi plant as a collective 4550 MWe plant rather than 6 individual and independent plants. Had the plant been a single reactor of this combined power, the consequences of the tsunami would certainly have been much more severe. The fact that the plant was subdivided into six smaller units with power levels ranging from 440-1070 MWe limited the total consequences; in fact, two of the six units are still operable.

The NuScale plant is designed from the outset as a multi-unit plant with careful consideration of all multi-module impacts, including common-cause failures and accident propagation. Analysis to date indicate that in all cases, the subdividing of the total plant capacity, and concomitant hazard, into smaller units reduces the potential consequences from a severe event such as experienced in Fukushima.

C
Regulatory Implications
1. How active has NuScale Power been in engaging the NRC?

On December 31st, 2016, NuScale submitted the first ever Small Modular Reactor (SMR) Design Certification Application (DCA) to the Nuclear Regulatory Commission (NRC). NuScale’s application consisted of 12,000 pages of technical information. In March 2017, NuScale received notification that their first-ever SMR DCA was accepted for review by the U.S. NRC. By accepting the DCA for review, the NRC staff is confirming that NuScale’s submission addresses all NRC requirements and contains sufficient technical information to conduct the review. The NRC has targeted completing the certification process within 40 months after acceptance.

NuScale was a pioneer in pre-application NRC engagement, having begun the process in July 2008. NuScale made over 80 presentations and submitted 15 topical reports to the NRC - engaging the NRC on topics such as safety analysis, nuclear fuel, test programs, seismic analysis, and control room staffing.

2. Will you be requesting that the NRC relax or remove any safety regulations for your design?

No. The NRC sets a world standard for enforcing rigorous safety standards and they do not intend to compromise this for SMRs, including NuScale. However, a given level of safety can be achieved in a variety of ways. Traditional plants have relied on engineered backup systems and administrative requirements to meet those safety requirements. The NuScale design incorporates enhanced safety into the basic design through elimination of several design vulnerabilities, reducing the likelihood of accidents and mitigating accident consequences through assured, passive backup systems. These intrinsic safety features will replace many traditional approaches while maintaining or improving the overall safety of the plant.

3. How will your plant’s staffing requirements compare to current plants?

Staffing levels for operations and security will be subject to review by the NRC and will be appropriate for safe and secure operations. The elimination of many systems due to the simplicity of the modules will significantly reduce operator workload and allow for more automation in the control and monitoring of the reactors. The number of operators will be evaluated based on workload requirements and will be sufficient to achieve the same level of plant safety as for large, traditional designs. Similarly, the below-grade placement and compact footprint of the NuScale plant adds intrinsic security; which will help to minimize traditional security force requirements.

4. Why do you think that the Emergency Planning Zone can be reduced?

NuScale is working with other nuclear industry leaders through the Nuclear Energy Institute to develop a basis for quantitatively evaluating the extent of emergency planning and preparedness for a specific plant based on potential risk to the public. Risk can be reduced in several different ways; the traditional approach has been to define a large (10 mile radius) zone within which certain physical infrastructure and administrative procedures are applied as a precautionary measure. A more elegant approach, and the one adopted by NuScale, is to reduce risk through intrinsic design features that eliminate, reduce, or mitigate consequences of potential accidents. It is expected that the emergency management actions and the size of the emergency planning zone will be adjusted to be commensurate with the level of risk posed by the plant, resulting in a risk to the public that is equal to or below current plants. The methodologies and approach proposed by NEI to define the size of the EPZ are the same as those that originally were used to set the 10 mile zone for existing plants, thus reinforcing the principle that SMR plant safety levels will meet or exceed existing plants.

5. Doesn’t having SMRs at more sites create a higher security and proliferation risk?

The NuScale plant design builds in a number of intrinsic features that further reduce security and proliferation risks, even compared to traditional nuclear plants, which are already considered highly secure. The very resilient plant design, which is achieved through system simplification, reliance on natural phenomena for backup safety systems, and application of traditional defense-in-depth principles reduces the plant’s vulnerability to external attack or internal sabotage. Additional design features ensure that control over the nuclear fuel elements is both secure and verifiable. All safety-related equipment resides inside one robust reactor building, the majority of which is below ground and immersed in a common pool of water.

D
Economic Competitiveness
1. Given the well-known economy-of-scale principle, why do you think a NuScale plant can be competitive with large plants?

Economy-of-scale can reduce unit costs for systems that are fundamentally of the same design. NuScale has chosen a different economic principle, economy-of-small, to take advantage of design simplicity that can only be achieved in small system sizes. Recent studies by the Columbia University Business School, for example, have analyzed economies of size and confirmed significant advantages to modular approaches. Many traditional plant components are eliminated and many remaining components are standard “off-the-shelf” commodities. The economic efficiencies of replication also reduce costs by allowing the manufacturer and operator to move through traditional learning processes more quickly. Collectively, we feel that all of these economies-of-small factors will allow us to be highly competitive.

It should be noted, however, that the NuScale design, and SMRs in general, extend beyond traditional large-plant markets and provide a more affordable and flexible solution for non-traditional customers located in smaller grid regions. For these customers, large amounts of power are not needed and alternative energy options are generally priced very high. In other words, a NuScale plant offers many customers a nuclear energy option where none previously existed.

2. Won’t investors see your new design as too big of a financial risk?

A major goal for NuScale is increased affordability. This translates to lower upfront capital investment due to the smaller unit size of the modules and incremental capacity growth due to the multi-unit design of the plant. This will enable the owner to generate revenue earlier than with a single unit large plant. These same features make the plant more attractive to investors because of the lower initial commitment level and earlier return on investment. Initial discussions with the investment community support this claim—they are significantly interested in the SMR business model. In fact, the NuScale deployment model yields a total project cost that is less than the interest costs of some proposed large nuclear plant construction projects.

3. What are the “economies of small” that you advertise?

There are many contributors to the economies-of-small, most of which are not unique to NuScale and have been demonstrated in several other industries. Columbia University published an analysis titled Small Modular Infrastructure in July of 2012, highlighting many well-known industrial examples, which we expect to be captured in our deployments. For example, economy-of-small was successfully applied to the coal plant industry in the 1970-1980s, which experienced a move toward more standardized ~200 MW boilers, and the mainframe computing industry in the 1990s, which replaced large single-processor machines with arrays of small parallel processors. Some of the more significant factors include: design simplification due to smaller heat load per reactor, reduced materials due to eliminated systems and components, labor efficiencies due to the higher level of factory fabrication and replication, faster learning with respect to manufacture and operations, and higher capacity factors due to multiplicity of generating units.

4. You advertise factory fabrication—so what?

The value of modularization has been proven in several construction industries, including the construction of large nuclear plants. NuScale will be using this modular construction approach throughout the plant and uniquely extends this approach to modularization of the nuclear steam supply system. The entire nuclear module, including the containment vessel will be completely fabricated within a factory environment. This provides a number of advantages resulting from the favorable and controlled environment within the factory compared to on-site construction. These include: improved labor efficiency, which is estimated to result in an 8-fold decrease in labor cost compared to on-site construction labor; improved quality; improved reliability, ease of inspection, and a centralized and stable skilled workforce.

5. Won’t the complexities of many modules in a plant cause high operating and maintenance costs?

This would be true if the modules are small replicas of a large unit, but they are not. By designing each module with a capacity of only 160 MWt and with assured removal of the decay heat, the modules and auxiliary systems are significantly simplified with the elimination of many traditional components. For example the NuScale design contains no reactor coolant pumps (RCP’s), which are one of the more expensive, maintenance-intensive and sensitive components in many plant designs. RCP failure results in immediate plant shutdown and contributes to plant unavailability. At NuScale we eliminate this event entirely since our design relies on gravity-driven natural circulation of the coolant. This improves reliability and reduces maintenance. Also, the high level of independence of the modules, including the turbine-generator systems, helps to minimize the potential for propagation of events across modules.

6. Won’t the compact size and integral design make routine maintenance more difficult?

The compact arrangement of components in an integral reactor design does present inspection and maintenance challenges. However, standard inspection techniques are still applicable and achievable with reduced scale probes. Offsetting this challenge is the fact that the NuScale systems are significantly simplified, which will require less total maintenance effort. When maintenance is required, only the involved module will be taken off-line while the others continue to operate, thus dramatically reducing the economic impact of the maintenance. Key features such as the plant’s electrical systems are being designed to support on-line maintenance without jeopardizing worker safety and while maximizing power availability of the plant. Also, maintaining spare parts in inventory to quickly replace suspect or defective components becomes a more tractable option than for single unit large plants because of the multiplicity of modules within the plant, the standardization among modules and lower cost for module parts.

7. Why do you only advertise a 12-module plant?

The NuScale design offers a truly scalable solution for customers. Plant sizes can vary from a single module up to 12 modules in a single plant, depending on the owner’s need. Further expansion can be achieved by placing multiple plants on the same site, much like traditional large unit sites. We have selected the 12-module plant as a reference design for initial licensing. This choice is driven by early customer preference, which favors a plant size of nominally 500 MWe — a very manageable size for grid stability considerations and well matched to the important market associated with the replacement of aging coal-fired power plants.

8. Does the elimination of primary pumps cause the NuScale plant to be less efficient and increase the cost of generated electricity?

NuScale decided to eliminate primary coolant pumps and supporting equipment by relying instead on gravity-driven natural circulation of the coolant. The potential loss of efficiency due to a lower coolant flow rate is compensated for by increasing tube surface area in the steam generator to achieve the same heat removal rate. We do this by using a compact helical coil steam generator with a very large surface area within a compact fluid volume.

Also, the NuScale steam generators produce significant steam superheat, which improves thermal efficiency and eliminates moisture separator, dryer and reheater equipment. Full scale testing in prototypical helical coils confirms both the heat transfer and superheat performance of our design. Hence, we expect a power conversion efficiency similar to existing plants and an overall cost savings from the elimination of several components and associated maintenance demands.

9. What about the nuclear waste problem—won’t NuScale make it worse?

First, it is important maintain a proper perspective: the “nuclear waste problem” is a political stalemate, not a technical issue. Secondly, the amount of nuclear waste produced in a nuclear plant is dwarfed by the voluminous waste produced from most other energy technologies. The good news about nuclear waste produced in a NuScale plant is that it is exactly the same as most of the other 440 nuclear plants operating world-wide; hence, we know a lot about its characteristics and how to treat it. Specifically, we know very accurately the composition of the discharged fuel, the radiation hazard, the rate of decay of the self-generated heat, and its amenability to recycling, should the U.S. decided to embark on this path similar to other major nuclear energy countries.

10. Can NuScale’s SMR technology be complementary to Renewables?

Yes. NuScale’s SMR technology includes unique capabilities for following electric load requirements as they vary with customer demand and rapid changes experienced with renewable generation sources.

There are three means to change power output from a NuScale facility:

Dispatchable modules – taking one or more reactors offline over a period of days

Power Maneuverability – adjusting reactor power over a period of minutes/hours

Turbine Bypass – bypassing turbine steam to the condenser over a period of seconds/minutes/hours


NuScale power is working with industry leaders and potential customers to ensure that these capabilities provide the flexibility required by the evolving electric grid. This capability, called NuFollowTM, is unique to NuScale and holds the promise of expanding the deployment of renewables without backup from fossil-fired generating sources, such as natural gas-fired, combined cycle gas turbines (CCGTs).

11. How does NuScale’s SMR fit into the existing infrastructure?

Each NuScale Power ModuleTM produces 50 MWe (gross), and up to 12 modules can be located at a single NuScale power plant, producing about 570 MWe (net) when all modules are in operation. The size and modularity of the NuScale SMR allow a high degree of flexibility for deployment in support of both electrical and non-electrical applications. The scalability feature makes the technology well-suited as a replacement for retiring coal-fired plants, most of which are less than 300 MWe. Relative to contemporary full-scale nuclear plants, NuScale SMRs have more siting flexibility on existing transmission grids, especially when used as replacement for retiring coal plants. In addition, because only one SMR module is refueled at a time, 92% of the power from a 12 module plant can remain on-line during refueling, providing continuous power throughout the plant lifetime. We estimate that the plant’s capacity factor will exceed 95% – making it one of the most reliable electric generation systems available.