Company reveals design information at ANS San Diego meeting
Billionaire Bill Gates has generated lots of media buzz for TerraPower, which is creating a radically different reactor design called the “traveling wave.” However, its technology, size (500-1,000 MW), and untested fuel may make for a long path to commercial success despite $35 million in new venture capital announced in June.
By comparison, Advanced Reactor Concepts (ARC), a Reston, VA, firm is developing a 100 MW small modular reactor (SMR) which relies on well-understood fuel developed for a sodium-cooled fast reactor that was actually built and operated at the Argonne National Laboratory West site in Idaho.
In an exclusive interview with this blog, Irfan Ali, ARC’s CEO, said the first round of design work is done and the hunt is on for serious investors.
“This is a major milestone,” Ali said. “We are now talking to potential customers and corporate investors.”
“We’re particularly interested in having conversations about developing a manufacturing capability to build these reactors.“
ARC released a white paper and a brochure with design information at the ANS conference held in San Diego earlier this month. Some of the principals on the design team have long experience with sodium-cooled fast reactors having worked at Argonne on the Integral Fast Reactor (IFR) and EBR-II.
The attractiveness of the ARC-100, Ali says, is that, “Factory built SMRs at 100 MW are far cheaper per unit of delivered power than the big reactors at 1,000 MW built on site.”
The target customer for the ARC-100 is most likely in a developing nation with an electrical grid that does not have the capacity to deliver 500 MW or more of electricity from a single plant to customers across the country.
The local customer could also be a water utility interested in desalinization or a local power authority interested in distributed power.
In some cases, Ali said, “the grid might not even be there which offers populations the opportunity to invest in localized electricity production.”
Ali says the ARC-100 is “sized for local or small grids.”
“We see customers buying a distributed fleet of the reactors because of their long refueling interval of 20 years.”
Getting power out of the reactor
The inlet temperature, according to a specification sheet, is 355 degrees C. The outlet temperature is 510 degrees C. The outlet temperature is what is made available to the balance of plant. The reactor immersed in ambient pressure liquid sodium. The intermediate loop is also liquid sodium.
Transfer of heat to a turbine is being developed to use to Brayton Cycle which uses liquid CO2 yielding an expected 40% efficiency rate for heat transfer. However, Ali said the company is also working with turbine manufacturers to develop steam applications. (Image: World Nuclear News)
Answer on nonproliferation issues
In an answer to critics of nuclear energy who worry about bomb makers, Ali points out the fuel for the ARC-100 is sealed in the reactor, used for 20 years, and then returned to the factor, or a regional fuel center, for reprocessing. The customer doesn’t touch the fuel, stores any on-site, or manages the used materials.
“The customer never has access to the fuel.” Ali said.
According to the first phase design information provided by the company, the “fuel cartridge” is inserted in an underground portion of the reactor. There are no safety-related systems in the balance of plant. The reactor vessel installed underground and is 15 meters high with a diameter of about 7 meters. See conceptual image left.
The fuel itself is enriched to an average of 14% depending on customer requirements. The specifications for the fuel are found in a database developed for the EBR-II reactor which means extensive first-of-a-kind fuel testing required for some of the other fast reactor SMRs won’t be needed for the ARC-100.
“It is a proven metal-alloy fuel,” Ali said.
On the reprocessing side of the fuel cycle, creating new fuel for the ARC-100 does not involve separating pure plutonium that could be used in nuclear weapons. Instead, it keeps the plutonium mixed with other long-lived radioisotopes so that it cannot be used in making bombs.
Ali said the company is now holding “pre-application discussions” with the NRC ahead of formally submitting the reactor for design certification. Ali did not indicate a date when the firm would formally submit a package to the NRC.
Ali knows he faces the same challenges as other SMR developers. How fast ARC gets to a market position with a "fleet" of 100 MW units will be a function of the interest of investors, the efficiency of the regulators, developing a manufacturing capability, and, above all, getting customers to book orders.
Prior coverage on this blog
- January 21, 2010 – Small fast reactor to offer 100 MW
- June 24, 2010 - The Capacity Factor blog has additional technical details.
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