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SMR company NuScale Power successfully completes helical coil steam generator testing

NuScale Power, a company developing small modular reactor technology (SMR) (earlier post), recently successfully completed its helical coil steam generator (HCSG) testing activities at the SIET S.p.A. (SIET) facilities in Piacenza, Italy. During that same time period, the US Nuclear Regulatory Commission (NRC) conducted a successful quality assurance (QA) inspection of the testing activities.

The NuScale integrated reactor pressure vessel contains the nuclear core, the HCSG, and a pressurizer. The HCSG consists of two independent sets of tube bundles with separate feedwater inlet and steam outlet lines. Feedwater is pumped into the tubes where it boils to generate superheated steam. A set of pressurizer heaters is located in the upper head of the vessel to provide pressure control. The entire Nuclear Steam Supply System (NSSS) is enclosed in a steel containment that is 24.6 m (80 ft) long by 4.6 m (15 ft) in diameter.

NuScale HCSG. Source: NuScale. Click to enlarge.

The NRC inspection team concluded that NuScale’s and SIET’s QA policies and procedures complied with the applicable requirements, and that SIET’s personnel were implementing these policies and procedures effectively in support of NuScale’s HCSG testing activities.

NuScale is currently developing and testing computer code design analysis software to support the NRC design certification of their advanced light water reactor design. The NuScale design includes a first-of-a-kind HCSG for conversion of nuclear heat into process steam.

NuScale contracted the services of SIET for the full-scale testing of the HCSG performance over the expected range of reactor operating conditions. SIET has extensive experience with similar heat exchanger test bundle fabrication and testing for other reactor vendors.

NuScale’s test aimed to:

  • Design and test a steam generator stabilization system so that stable steam generator operation is assured;

  • Provide ample data covering the full range of operation to benchmark NuScale HCSG computer codes and models; and

  • Measure steam generator outlet conditions as a function of primary and secondary system conditions and tube geometry.

In December 2013, NuScale Power was selected as the sole winner of the second round of the US Department of Energy’s (DOE) competitively-bid, cost-sharing program to develop nuclear Small Modular Reactor (SMR) technology. As part of the award, NuScale will receive funding that will support the accelerated development of its NuScale Power Module SMR technology. NuScale and DOE are currently negotiating a cooperative agreement that formalizes the public-private relationship and establishes milestones for the five-year funding program. (Earlier post.)

As the only US-based company established solely for the commercialization of its SMR, NuScale Power has developed a novel and proprietary technology for an innovative, simple, safe, economic and scalable small modular reactor. Natural forces of physics—gravity, convection, and conduction—are used for normal operations and safe shutdown. This eliminates many of the large and complex systems (e.g., reactor coolant pumps, motors, valves, large-diameter reactor coolant system piping) found in today’s nuclear power plants and other SMR designs. As a result, the plant is safe, simpler, and less expensive to build and operate, according to the company. At 45 megawatts per module, a NuScale power plant can include as many as 12 NuScale Power Modules to produce as much as 540 MW.

The NuScale design was initially developed in 2000 and has been demonstrated and in testing programs since 2003 in a fully-instrumented one-third scale electrically-heated test facility in Corvallis, OR. In addition, NuScale commissioned a full-scale multi-module control-room simulator in May of 2012. Both facilities were US SMR industry firsts.



Could be well suited for small cities and large towns.
Some sort of back up power or grid would be required.

Fatory mass production could lower the effective energy produced cost and ensure higher quality.

A cluster of 10 units or so could replace one average size current dirty CPP.


I hope that this works out and is brought into production on a timely basis. If the traveling wave reactors come along later, they can presumably burn the waste.

Any system that is not isolated in a completely remote area will be hocked to a grid and with 2 or more units, they would not need a backup systems as they will have a very high up-time or availability (almost certainly greater than 95%). However, it is common practice to have a backup power source so the controls keep working if the grid goes down but it would not be a disaster if the power is completely lost as there are no cooling pumps that must keep running to prevent a meltdown.


"The NuScale design was initially developed in 2000 and has been demonstrated and in testing programs since 2003 in a fully-instrumented one-third scale electrically-heated test facility in Corvallis, OR."

"In December 2013, NuScale Power was selected as the sole winner of the second round of the US Department of Energy’s (DOE) competitively-bid, cost-sharing program to develop nuclear Small Modular Reactor (SMR) technology."


Solar PV energy costs have fallen by 99%, 8 fold since 2000.

If this SMR's unstated cost is also a penny on a dollar it might be able to compete, if approved during further decades, safe, and all the thousands of years of half life nuclear waste disposal is legally in place.


Traveling Wave has stopped traveling. Gates is looking at molten salt and other ideas.


kelly, even if energy from PV was effectively free, the cost of storing it and turning it into power-on-demand (dispatchable power) would cost more than nuclear.

Adding storage reduces the EROI of PV to the neighborhood of 2.  The all-in payback time is well over a decade.  PV on a planet may be good in remote areas and for emergencies, but it is not sustainable in the least.



Those are based on this paper


Which uses a 10 day storage scenarios, and assumes a 3 to 1 efficiency drop for thermal to electrical generation (33.3% efficient). A worst case scenario. It also does not take into account long distance or regional power sales. It ignores that just about every power market has an additional 50% of generally unused capacity built in for summer peaks.

Those assumptions aren't even close to reality. A new natural gas combined cycle turbine does 62%, a new coal with supercritical rankine 46% (50% be end of decade). A fuel cell with combined cycle does up to 80%. New supercritical carbon dioxide brayton cycle will take combined cycle natural gas to 70% easy, and a coal plant to 50% (more if you combine cycle the coal plant). Nor will more than 10 hours of battery storage ever likely be used (so it was 24x over assumed), unless the levelized cost of storage for batteries drops to unrealistically low levels.

It also doesn't take into account that you can convert a small coal plant to a natural gas peaker for like $0.35 per watt. Even if you count that capital and operating cost for a nameplate watt of solar PV or wind it is still not an issue.

That link does not support your conclusion (nor does the paper support its own conclusions) except with strenuously bad assumptions.

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