As part of its design certification efforts, NuScale Power, LLC completed a test program to obtain heat flux data for its nuclear fuel. Because the NuScale design does not rely on pumps to circulate water inside the reactor, the NuScale fuel bundle is designed specifically for operation under natural circulation conditions.
Beginning in September 2012 and successfully completed March 15, 2013, the tests were conducted under fully-prototypic conditions in a specialized test rig at Stern Laboratories in Ontario, Canada. The test program was conducted under the quality assurance requirements of 10 CFR 50 Appendix B.
The U.S. Nuclear Regulatory Commission witnessed testing and performed an inspection of NuScale’s oversight of the program. Canadian regulators also observed testing.
A full-length, full-power, electrically-heated fuel assembly mock-up with spacer grids was tested for a wide range of natural circulation flow rates with both uniform and cosine shape power profiles. The data, known as critical heat flux (CHF) data, is being used to define the limiting conditions for fuel performance and to validate NuScale’s safety analysis computer codes.
The completion of this test program marks another major achievement for NuScale. Thus far, NuScale has successfully completed two major test programs and has three additional test programs underway.
NuScale has developed technology for building safer, smaller, scalable nuclear power plants. Using light water reactor technology, the NuScale Power Module is cooled by natural circulation, entirely self-contained and installed underwater and underground to maximize safety.
The NuScale design was initially developed in 2000 under a DOE-funded research program and demonstrated in a one-third scale electrically-heated test facility in Corvallis, OR, starting in 2003.
NuScale was the first US-based SMR vendor to begin discussions with the U.S. Nuclear Regulatory Commission and has been engaged in pre-application efforts since 2008.
NuScale is developing modular, scalable commercial nuclear power technology. NuScale’s design offers the benefits of carbon-free nuclear power but takes away the issues presented by the cost of installing large capacity. A nuclear power plant using NuScale’s technology is comprised of individual nuclear power modules; each produces 45 MW of electricity with its own combined containment vessel and reactor system, and its own designated turbine-generator set.
A power plant can include as many as 12 NuScale integral PWR modules to produce as much as 540 MW. NuScale power plants are scalable — additional modules are added as customer demand for electricity increases. These multi-module plants are highly reliable — one unit can be taken out of service for refueling or maintenance, or a new unit added, without affecting the operation of the others.