Progress to factory assembled small modular Nuscale Light Water Reactor

NuScale Power has successfully installed a full-length test version of its nuclear-powered steam generator in Piacenza, Italy. The tests will provide important input into NuScale’s Design Certification Application to the Nuclear Regulatory Commission, which it expects to file in the second half of 2016. NuScale expects to deploy its first system for the Utah Associated Municipal Power Systems’ Carbon Free Power Project, with a potential site in Idaho. It plans to submit the UAMPS project for approval in 2017 and begin operations in late 2023. In late 2013, the U.S. Department of Energy selected NuScale for a commercialization project. It signed a $217 million cost-share contract with DOE in June.

Last week, the Washington state senate passed a bill requiring the state’s commerce department to “coordinate and advance the sitting and manufacturing of small-scale reactors,” according to the bill’s text. It goes on to define the technology in questionas, “a scalable nuclear power plant using reactors that each have a gross power output no greater than three hundred megawatts electric, and where each reactor is designed factory manufacturing and ease of transport, such as by truck, rail, or barge.”

There are many competing global small modular nuclear reactor projects.

China is building the HTR-PM high temperature reactor. It is expected to be in commercial operation in 2017. China is planning to build and buy 18 more in the next phase. They are expected to get to a cost of $1500/kw with volume production.

Nuscale Plant Overview

Each NuScale Power Module is a self-contained module that operates independently of the other modules in a multi-module configuration. However, all modules are managed from a single control room.

The reactor (1) measures 65 feet tall x 9 feet in diameter. It sits within a containment vessel (2). The reactor and containment vessel operate inside a water-filled pool that is built below grade. The reactor operates using the principles of natural circulation; hence, no pumps are needed to circulate water through the reactor. Instead, the system uses a convection process. Water is heated as it passes over the core (3). As it heats up, the water rises within the interior of the vessel. Once the heated water reaches the top of the riser (4), it is drawn downward by water that is cooled passing through the steam generators.

NuScale Power Module details include:

Thermal capacity – 160 MWt
Electrical capacity – > 50 MWe (gross)
Capacity factor – >95 percent
Dimensions – 76′ x 15′ cylindrical containment vessel module containing reactor and steam generator
Weight – ~ 700 tons as shipped from fabrication shop
Transportation – Barge, truck or train
Cost – Numerous advantages due to simplicity, off-the-shelf standard items, modular design, shorter construction times, <$5,000/KW Fuel – Standard LWR fuel in 17 x 17 configuration, each assembly 2 meters (~ 6 ft) in length; 24-month refueling cycle with fuel enriched less than 4.95 percent”

Modular factory built advantages

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.

NuScale’s innovative and comprehensive safety features are incorporated to provide stable long-term nuclear core cooling under all conditions, including severe accidents. These safety features include:

* The Triple Crown for Nuclear Plant Safety breakthrough – safely shuts down and self-cools, indefinitely with no operator action, no AC or DC power, and no additional water.
* High-pressure containment vessel, redundant passive decay heat removal, and containment heat removal systems.
* The integrated design of the NuScale Power Module, encompassing the reactor, steam generators, and pressurizer, and its use of natural circulation eliminates the need for large primary piping and reactor coolant pumps.
* A small nuclear fuel inventory; since each 50 MWe (gross) NuScale Power Module houses approximately 5% of the nuclear fuel of a conventional 1,000 MWe nuclear reactor.
* Containment vessel submerged in an ultimate heat sink for core cooling in a below grade reactor pool structure housed in a Seismic Category 1 reactor building.

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.

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).

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.

SOURCES – Motherboard, bizjournal, Wikipedia, World Nuclear Association, Nuscale