Invoice Gates’ nuclear innovation agency TerraPower has damaged floor on the non-nuclear portion of Kemmerer Unit 1, a 345-MW Natrium sodium-cooled quick reactor (SFR) energy plant. The groundbreaking on June 10 makes the federal demonstration venture the primary superior nuclear reactor venture to maneuver from design into building within the Western Hemisphere, the corporate famous.
The venture is taking form in Lincoln County, Wyoming, about 3 miles from PacifiCorp’s three-unit 604-MW coal and gasoline–fired Naughton Energy Plant, furnished with as much as $2 billion in approved funding below the Division of Power’s (DOE’s) Superior Reactor Demonstration Program (ARDP).
Bellevue, Washington, headquartered TerraPower submitted a building allow software (CPA) to the U.S. Nuclear Regulatory Fee (NRC) in March 2024 (by means of a completely owned subsidiary US SFR Proprietor, and the NRC accepted the CPA on Might 21. Whereas the NRC is now engaged on establishing a evaluate schedule for the CPA, TerraPower says it anticipates submitting the working license in 2027, permitting it to start building on the nuclear island in 2026 and full the plant “this decade.”
Upon completion, the Natrium demonstration plant shall be a completely functioning industrial energy plant that may showcase the pioneering know-how and supply energy capability within the PacifiCorp service space. TerraPower additionally underscored that the venture is at the moment “the one coal-to-nuclear venture below improvement on the planet.”
A Pioneering Nuclear-Storage Hybrid
Kemmerer 1 shall be a hybrid nuclear facility integrating an 840 MWth pool-type Natrium SFR reactor with a nitrate molten salt-based vitality storage system. The plant’s vitality storage has the potential to spice up the system’s output to between 100 MWe and 500 MWe of energy for greater than 5.5 hours when wanted, ramping at 10% a minute, the agency says.
The plant primarily includes a nuclear island (NI), housing the reactor (in a compact and easy security envelope) together with its core and first warmth transport programs, and the vitality island (EI), containing the thermal vitality storage tanks, steam generator, feedwater system, condenser, turbine, and supporting programs. The islands are designed to perform independently with minimal interdependencies, related solely by the nuclear island salt system.
At the beginning of the method, the reactor makes use of sodium-bonded metallic gas with excessive chromium martensitic metal (HT9) cladding to maintain a nuclear chain response. The reactor operates by circulating sodium coolant by means of its core, the place it absorbs the warmth generated by nuclear fission within the gas assemblies. This thermal vitality is then transferred by way of in-vessel pumps and warmth exchangers throughout the Main Warmth Transport (PHT) system to an Intermediate Warmth Transport (IHT) system. In keeping with TerraPower, the reactor’s warmth output is larger than 500C (930F).
In comparison with a conventional sodium quick reactor (which generates steam by means of a sodium-to-water steam generator), Natrium removes the sodium water response solely, as Mark Werner, TerraPower vice chairman of plant supply, instructed the NRC on Might 15. “We do have an air cooling system that removes warmth immediately from the surface of the reactor, and this enables us, successfully, indefinite passive emergency decay warmth removing within the case of a extreme irregular occasion,” he mentioned. “Since our reactor is a pool-style sodium reactor, we don’t function at a excessive coolant stress, we’re a really low coolant stress, close to atmospheric stress.”
Throughout regular operations, the IHT directs the reactor’s generated warmth to the Nuclear Island Salt System (NSS) for vitality storage or use. Throughout startup and shutdown, warmth is dissipated into the environment by means of the Intermediate Air Cooling System (IAC). (The method continues because the heated sodium from the core mixes within the reactor’s scorching pool after which circulates by means of intermediate warmth exchangers earlier than being recirculated again to the core.)
Secondary programs then rework this generated warmth into electrical energy. The warmth from the IHT is transferred to the nuclear island salt system (NSS) by way of sodium-salt warmth exchangers, shifting by means of the Salt Warmth Transport System to the Thermal Salt Storage System (TSS). The salt saved within the TSS scorching tank is pumped by means of the steam mills and despatched to the TSS chilly tank. The steam generator gear converts water into steam by passing the recent salt by means of an economizer (water preheater), evaporator, superheater, and reheater, offering steam to the turbine to supply energy.
“All the measurement of the nuclear island is roughly 16 acres. The general web site space is roughly 44 acres. When normalized to energy ranking, the Natrium system has a smaller footprint in comparison with different Era IV reactors,” TerraPower notes.
One other Step Ahead for the ARDP
As POWER reported, in 2020, the DOE chosen TerraPower and X-energy because the preliminary awardees of its ARDP, suggesting that the 2 tasks successfully fulfilled its standards and had been most able to creating distinctive superior nuclear reactors and provoke their operation by 2028.
The ARDP’s tight seven-year timeframe spurred speedy improvement by the 2 corporations. TerraPower picked the Wyoming web site in 2021 for its Natrium demonstration. Whereas X-energy’s venture was initially slated to be developed with Power Northwest in Washington state, the corporate introduced in Might 2023 that it will transfer its Xe-100 pebble-bed high-temperature gasoline reactor demonstration to a Dow web site in Seadrift, Calhoun County, Texas.
Each builders are nevertheless fielding challenges associated to their first-of-a-kind tasks. Every is working to satisfy a protracted record of pioneering milestones as they relate to analysis, plant design, gear testing and qualification, and procurement and building.
TerraPower is now eyeing a 2030 begin date, citing a scarcity of HALEU availability. In July 2023, the firm introduced a memorandum of understanding with Centrus Power to “considerably increase their collaboration” to make sure the demonstration reactor could have entry to HALEU to satisfy the 2030 schedule. And, as POWER not too long ago reported, the firm has taken extra steps to bolster a home nuclear gas provide chain. X-energy, in the meantime, suggests it’s getting ready a building allow software, anticipating that plant building will start in 2026.
TerraPower has additionally taken steps to cement its suppliers. It says it’s planning for Bechtel Corp. to construct the reactor “with the assistance of many direct workers and subcontractors.” In February, it awarded contracts to GERB for Kemmerer 1’s seismic isolation gear, Thermal Engineering Worldwide for sodium-salt warmth exchangers, Hayward Tyler for sodium pumps, Framatome for gas dealing with machines, and Teledyne Brown Engineering for the In-Vessel Switch Machine.
On Monday, the corporate indicated it has additionally pinned down estimates of the workforce it might want to construct and function Kemmerer 1. “Roughly 1,600 staff shall be wanted for building on the venture’s peak,” it mentioned. “Building is about to span 5 years. As soon as the plant is operational, the corporate estimates that 250 folks will assist day-to-day actions, together with plant safety.”
Way more work stays. Nevertheless, “This groundbreaking represents the start of the following period of nuclear vitality,” mentioned Chris Levesque, TerraPower president and CEO. “The Natrium reactor is greater than a design, it’s a plant coming to life that may assist each the clear vitality transition and our historic vitality communities,” he famous.
—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).
