NuScale Power, long touted as the most mature of the various small reactor proposals on the market, has failed to make the cut in the U.K.’s SMR design competition, undertaken by the government’s Great British Nuclear (GBN).
Four competitors – GE Hitachi, Westinghouse, Holtec International, and Rolls Royce – made the finals and will submit “best and final” offers to the government. The semi-finals initially included six vendors, but France’s EDF bailed out in July, leaving five.
All four finalists – and unsuccessful NuScale – share some interesting commonalities. All are light water reactors, with H2O providing both coolant and neutron moderator, eschewing some of the “advanced” reactor designs that have drawn considerable attention lately, such as TerraPower’s 345-MW sodium cooled Natrium reactor.
Unlike Natrium and others, all the finalists employ conventional low-enriched uranium fuel, rather that the hyped “High Assay, Low Enriched Uranium” HALEU favored by many of the so-called advanced designs, and which is not commercially available. [Why don’t we just call it “medium enriched uranium,” which is what it is – enriched above 4.95% and below 20%?—Ed.]
Here are some of the key details of the finalists:
- The Westinghouse AP 300 is a 300-MW scaled down version of its AP 1000 pressurized water reactor (PWR), the company’s current 1000-MW conventional reactor, with six in operation, four in China and the two Vogtle units in Georgia. The AP 300 features passive convection cooling, designed, the company claims, so the reactor can shut down “without operator action, back-up power or pumps.”
- The GE Hitachi BWRX-300 is a 300-MW boiling water reactor that also employs passive cooling and natural circulation. GE touts its use of “modular and open-top construction techniques” and “advanced concrete solutions and innovative techniques that have been proven in the oil and gas, tunneling and power industries.”
- The Rolls Royce SMR is a whopping 470-MW PWR, well beyond the 300-MW size that has traditionally defined “small modular reactor.” Maybe a new term is needed, perhaps “husky modular reactor” or HMR? The company, best know for its iconic luxury autocars, says that “the whole power station is constructed using around 1,500 standard transportable modules manufactured and tested in off-site factories to minimise activity on site.”
- Holtec’s SMR-300 is a 300-MW PWR that, like all the others, is allegedly “walk-away safe.” Unlike the others, Holtec says the reactor core “is located deep underground, protected by a steel and concrete containment enclosure,” adding that “a large water inventory protects the reactor core, which is designed to always remain deeply submerged.”
Given that all four “small” modular reactors are rather large, that may have been what put NuScale out of the running, although the Brits are not disclosing any details of their selections. The NuScale VOYGR reactors are 77-MW PWRs, designed to be built in gangs of 4, 6, or 12 units. NuScale’s earlier 50-MW reactor design won a U.S. Nuclear Regulatory Commission license, but the larger module awaits NRC action.
It is important to keep in mind that none of these small modular reactors have been built and operated, so what the vendors publish as advantages are as much marketing palaver as technical revelations. As the legendary Bob Pollard, the Union of Concerned Scientists first nuclear power safety engineer (1976-1996), was wont to say: “Paper reactors all work perfectly.”
GBN Chairman Simon Bowen told World Nuclear News earlier this year that the government hopes to choose “two or three technology providers – this would be for co-funding the technology all the way through to completion of the design, regulatory, environmental and site-specific permissions process, and the potential to place a contract for the supply of equipment. Each selected technology would have an allocated site with the potential to host multiple SMRs.”
Meanwhile, in South Korea, the Nuclear Safety and Security Commission has given the SMART 100 SMR standard design approval. The SMR is a 365-MW(t), 110-MW(e) design aimed at power production and thermal applications such as seawater desalination.
SMART stands for “System-integrated Modular Advanced Reactor 100,” originally developed by Korea Atomic Energy Research Institute (KAERI). The original, smaller design won Korean standard design approval in 2012, the first SMR in the world to win a regulatory green light. The current, beefed-up design is owned by a company consisting of KAERI, Korea Hydro & Nuclear Power (KHNP) and Saudi Arabia’s King Abdullah City for Atomic and Renewable Energy (KA-CARE). Smart Power Co. Ltd submitted the new design for a license in 2019.
World Nuclear News quoted KAERI: “The upgraded model is now ready for global export, particularly to Saudi Arabia, a key partner in the development of this technology.”
–Kennedy Maize
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