Frequently Asked Questions

NuScale FAQs

Corporate Commitment

  1. When was NuScale Power formed?
  2. Who provides the financial backing for NuScale Power?
  3. The NuScale design includes many innovations—is this intellectual property being protected?
  4. Is NuScale Power pursuing international customers and investors?
  5. Where do you expect the first NuScale plant to be built?

Enhanced Safety

  1. How has safety been enhanced?
  2. How do you know it will be safe?
  3. What is the significance of your “triple crown” announcement and how do you achieve it?
  4. Does the small containment structure of a NuScale module decrease safety?
  5. Didn’t Fukushima demonstrate that multi-module plants are too risky?

Regulatory Implications

  1. How active has NuScale Power been in engaging the NRC?
  2. Will you be requesting the NRC relax safety for your design?
  3. How will your plant’s staffing requirements compare to current plants?
  4. Why do you think that the Emergency Planning Zone can be reduced?
  5. Doesn’t having SMRs at more sites create a higher security and proliferation risk?

Economic Competitiveness

  1. Given the well-known economy-of-scale principle, why do you think a NuScale plant can be competitive with large plants?
  2. Won’t investors see your new design as too big of a financial risk?
  3. What are the “economies of small” that you advertise?
  4. You advertise factory fabrication—so what?
  5. Won’t the complexities of many modules in a plant cause high operating and maintenance costs?
  6. Won’t the compact size and integral design make routine maintenance more difficult?
  7. Why do you only advertise a 12-module plant?
  8. Does the elimination of primary pumps cause the NuScale plant to be less efficient and increase the cost of generated electricity?
  9. What about the nuclear waste problem—won’t NuScale make it worse?
  10. Can NuScale’s SMR technology be complementary to Renewables?
  11. How does NuScale’s SMR fit into the existing infrastructure?

Corporate Commitment

1. When was NuScale Power formed?

NuScale Power, LLC 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 the “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 NuScale design.

2. Who provides the financial backing for NuScale Power?

Since becoming NuScale’s majority investor and a key strategic partner for engineering, procurement and construction services in October 2011, it has provided most of the private financial backing for NuScale. As of the end of 2017, Fluor has invested over $475 million in NuScale. Several other key strategic partners also provide a small portion of NuScale’s financial backing. In December 2013, the U.S. Department of Energy announced their selection of NuScale Power under a competitive funding opportunity as the sole recipient of up to $226M in a financial assistance cost share award for the purpose of accelerating NuScale’s design development and certification by the U.S. Nuclear Regulatory Commission enabling potential deployment of the first plant by 2026.

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

NuScale has been very active in its pursuit of patent protection for the many innovations contained within our design. More than 350 patents are in force or pending in 20 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 global market opportunity estimated by some to be as much as $550B.

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 a site at the Idaho National Laboratory. It will be owned by the Utah Associated Municipal Power Systems (UAMPS).

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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. In addition to several new design innovations that further enhance safety, 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 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 size of the reactor and the assured passive heat removal mechanisms 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 learned from over 60 years of operation, 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 integral performance tests. Thirdly, our design is being thoroughly reviewed and will be certified by one of the world's leading regulators, the U.S. Nuclear Regulatory Commission (NRC).

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 provides for an unlimited period of cooling of the nuclear fuel 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 10 times higher than currently operating nuclear units. Secondly, the volume inside the containment is under vacuum conditions, which provides effective thermal insulation to the reactor vessel. This eliminates the need for insulation material on the reactor vessel, which has been the subject of sump clogging in existing plants. The vacuum also enhances steam condensation rates on the inside surface of the submerged containment in situations where steam is released from the reactor vessel, which in turn provides for very effective removal of heat from the primary system. Finally, the lack of oxygen inside containment while under vacuum conditions 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 systems that failed resulting in the damage to several of the Fukushima Daiichi reactor units do not exist in the NuScale design, and the level of resilience for a NuScale plant is substantially higher than that of the Fukushima plants. Regarding the implications of multi-unit sites, had the Fukushima Daiichi been a single plant of 4550 MWe plant rather than six separate and independent smaller units with power levels ranging from 440 to 1070 MWe, the consequences of the tsunami would likely have been more severe. The fact that the plant was subdivided into six smaller units with lower power levels 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 shows that in all cases, the subdividing of the total plant capacity into smaller units reduces the potential consequences from a severe event such as experienced in Fukushima.

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Regulatory Implications

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

On December 31, 2016, NuScale presented 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, the regulatory agency announced it had accepted NuScale's DCA for review. By doing this, the NRC staff confirmed that NuScale's submission addressed all necessary requirements and contained sufficient technical information to conduct the review. The NRC's final report approving NuScale's SMR design is expected to be complete by January 2021.

NuScale was a pioneer in the advanced reactor community in pre-application engagement with the NRC, having begun the process in July 2008. NuScale met with the regulatory agency more than 250 times and submitted 15 topical reports - engaging them on topics such as safety analysis, nuclear fuel, test programs, seismic analysis, and control room staffing.

2. Will you be requesting the NRC relax safety for your design?

No. NuScale's design will be the safest design ever approved by the NRC. The NRC's regulations were developed to address a particular type of reactor technology. For example, regulations assume safety-related electrical power is necessary. In the NuScale design, safety is assured without the need for these safety-related power supplies. The NRC regulations include a process by which applicants can propose an alternative to existing requirements, known as exemptions. This process ensures that the alternative approach protects public health and safety. NuScale includes some exemption requests in its design certification application. These exemption requests are necessary to properly address the passive safety approach inherent in NuScale’s design. The design certification application provides the justification for the safety of each alternative sought by NuScale.

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 design and automation in the control and monitoring of the reactors will significantly reduce operator workload. 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, integration of “security by design” principles, the below-grade placement and compact footprint of the NuScale plant adds intrinsic security; which will justify the use of a smaller security force than found in current large nuclear plants.

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 defense-in-depth principles reduces the plant’s vulnerability to the impacts from an 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 a very robust reactor building, the majority of which is below ground and immersed in a common pool of water.

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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 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 have traditionally been one of the more expensive, maintenance-intensive and sensitive components in current nuclear plants. RCP failure results in immediate plant shutdown and plant unavailability. At NuScale we eliminate the possibility of this event because our reactor coolant is naturally circulated – that is by the physically effects of change in density and buoyance of the primary water. This serves to lower capital cost, improve reliability and reduce maintenance.

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 have been 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?

This choice is driven by early customer preference, which favors a plant size of nominally 600 MWe — a very manageable size for grid stability considerations, but still not a small facility in terms of output, and well matched as a repowering option for the replacement of aging coal-fueled power plants, the majority of which are between 300 and 600 MWe. This facility sizes also presents favorable economics. While NuScale could easily design a facility to house fewer than 12 modules (i.e.: such as a “4-pack” or “6-pack”), we have limited our initial licensing activities to a 12-module design.

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

In keeping with our objective of providing a design of unparalleled safety and simplicity, we 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?

The amount of used or spent nuclear fuel 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, vary its output as necessary to support system demand as capacity varies on the system from intermittent generation. This feature is known as “load following.”

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

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-fueled, combined cycle gas turbines (CCGTs).

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

Each NuScale Power Module™ produces up to 60 MW of electricity, and up to 12 modules can be located at a single NuScale power plant, producing up to 720 MWe (gross) when all modules are in operation. The size and modularity of the NuScale SMR allow a high degree of flexibility to direct the heat output for either electricity production or for process head 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 traditional 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.

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