Nukes of the North: Copper Valley Electric Association Studies Micro Modular Reactor

CVEA provides electricity and heat to more than 3,800 business and residential customers from Glennallen to Valdez, and east to west from the Tok Cutoff to the outskirts of the Matanuska Valley. CVEA is not connected to the Railbelt grid or any other utility. The co-op uses a mix of hydropower and fossil fuel, relying more on combustion boilers in winter when hydro is less available.

The board of directors approved a strategic plan in 2021 to reduce CVEA’s dependence on fossil fuels. CEO Travis Million says, “Priorities for CVEA are to study the application of MMR technology in decarbonizing the utility’s energy portfolio, increasing efficiency, lowering the cost of operations, and stabilizing winter rates when an increase in diesel generation would be necessary.”

The study, to be completed by July, is meant to determine the technical feasibility, social acceptance, location, cost, and operating specifics of a small-scale nuclear power plant. CVEA is looking at Valdez to host the facility. The site, according to USNC, need not be much larger than a baseball field.

Only one power plant in the world currently uses small modular reactors. The 70-megawatt facility at Pevek, Russia, in the Chukotka region across the Bering Strait, is modeled on reactors in nuclear-powered icebreakers. Another small modular reactor began construction in China in 2021, scheduled for completion in 2026. 

The US Air Force has plans to deploy a 5-megawatt reactor at Eielson Air Force Base in 2027. If CVEA proceeds, its reactor would be operational no earlier than 2027 and, by that time, would be USNC’s third commercial deployment of MMR.

“Walk-Away Safe”

The technology at the heart of MMR is what’s called a fourth-generation nuclear energy system. Rather than a massive concrete vessel and hyperbolic cooling towers, the guts of MMR can fit inside two 40-foot shipping containers. The core, loaded with a 20-year supply of uranium fuel, is buried underground, upright, next to another module that circulates helium coolant. The helium transfers heat to molten salt, which is pumped to a neighboring steam turbine to drive the generator.

USNC calls MMR “walk-away safe,” requiring no active systems to remove heat and no need for outside power or water, eliminating those points of possible failure. In an accident, MMR is designed to shut down by itself and dissipate heat passively while radiation within the core is contained by the fuel itself.

The molten salt enables the system to store heat. While the reactor operates at a constant level, the heat transfer medium can be stockpiled at night, for example, and then released during the day when electricity demand is higher.

Because of its small size and modularity, MMR can be deployed at remote sites, such as mines or communities off the road system. Valdez, at the end of a major highway, promises a simpler deployment, if CVEA chooses that location. Each module is rated for 5 megawatts of electricity, so CVEA is studying the installation of two. If more capacity is needed, more modules can be added to the site.

As for nuclear waste, the MMR system would have the manufacturer reclaim the fuel cartridges at the end of their 20-year lifetime. Alaska statutes require spent fuel to be either stored on site or transported out of state.

The day before CVEA announced the feasibility study with USNC, Governor Mike Dunleavy requested legislation, Senate Bill 177, to facilitate the deployment of microreactors. It would exempt reactors under 50 megawatts from requiring legislative approval for siting.

In an email, CVEA’s Million says SB177 would align Alaska statutes with those in the Lower 48, with respect to nuclear energy. “That said,” he adds, “the passage of SB177 in no way ensures that a microreactor can be sited in Alaska, but it does eliminate a hurdle that is mostly political in nature.”

It also streamlines the requirements for studies, now spread across six state departments, relying instead on work being done by UAF and the Alaska Center for Energy and Power.