The members of Utah Associated Municipal Power Systems (UAMPS) are in talks to potentially transform the structure of what would be the first commercial-scale small modular nuclear reactor facility in the U.S., following a shakeup in the ownership and financing of the proposed Carbon Free Power Project (CFPP) at the Department of Energy's Idaho National Laboratory.

The number of modules used at the CFPP and the overall costs of the project are subject to change pending negotiations among many of the 47 municipal utilities around Utah and neighboring states that make up UAMPS, spokesperson LaVarr Webb said. The project was most recently envisioned as an estimated $6.1 billion, 720 MW plant that would use 12 small modular reactors (SMRs) operating at one site in what reactor developer NuScale Power calls a "multi-module configuration."

The discussions follow recent announcements by NuScale that the reactor will produce more power for the same costs than previously announced due to progress in the development of the reactor design. Several UAMPS members withdrew from the project earlier this year, ahead of a deadline to "off-ramp" their shares without incurring losses. These withdrawals came after delays in the project's construction schedule contributed to increases in cost estimates from $4.2 billion in 2018 to $6.1 billion today. 

Currently, 27 of the 35 members who originally signed up for shares in the project are still involved with the CFPP. The next opportunity for an off-ramp will come when the project hits the milestone of filing its combined operating and licensing application with the Nuclear Regulatory Commission, expected in 2023.

'We've seen this story before'

These developments have created concerns among some who see the growth of nuclear energy as necessary for the task of decarbonizing the electricity sector, but have been frustrated by the prohibitively high costs and extended timelines for constructing new nuclear plants. "We've seen this story before, and now the risk is to see it again with the first SMR project, which would damage the support for SMRs in general," said Jacopo Buongiorno, TEPCO Professor of Nuclear Science and Engineering at the Massachusetts Institute of Technology.

In concept, SMRs were supposed to be simple and scaled-down, and thus an answer to the problem of extraordinarily complex projects to build large conventional nuclear reactors that have become financial drags on their owners. The two most recent projects to build new nuclear plants in the U.S. were at the V.C. Summer plant in South Carolina, where two new units were abandoned mid-construction after $9 billion had been spent, and at the Vogtle nuclear plant in Georgia, where two units have been under construction for about a decade and have experienced billions in cost overruns and years of delays.

"It has become more difficult to build anything large," said Jessica Lovering, co-founder of the Good Energy Collective, a policy research organization that promotes nuclear energy as part of the solution to climate change. The cost increases and delays for the CFPP, however, do not necessarily mean that SMRs are on the same path, because the biggest cost savings may not materialize until the "nth-of-a-kind" reactors are being built and sold on a wider scale, as opposed to the "first-of-a-kind" represented by the CFPP, she said. 

"It doesn't look great to have communities pull out," Lovering said, but UAMPS' approach that allows off-ramping could "in the long run lead to a more sustainable project" because the commitment of those utilities that stick with the project is assured.

First-of-a-kind

UAMPS may switch to a configuration with fewer modules, but more capacity for dollars invested, Webb said. The utilities are reacting to recent announcements from NuScale, a startup that has been working on its 60-MW SMR module based on research from Oregon State University since 2007. 

NuScale says operators will be able to squeeze out more megawatts of power from the company's reactors when they operate 24/7 as baseload power, as opposed to load-following, when the reactor ramps up or down to provide a needed level of power. The result is a 25% increase in the capacity of a NuScale module to 77 MW, meaning a 12-module plant would have a capacity of 924 MW, according to a statement from NuScale.

NuScale announced this feature after "advanced testing and modeling tools" found that the NuScale module can operate at a higher level of thermal energy output without as much "thermal maneuvering"— the process in which the reactor power level is adjusted by methods like inserting or pulling back on control rods to induce or decrease nuclear reactions — as the company previously thought would be necessary, according to NuScale spokesperson Diane Hughes. "In particular, limiting the rate of control rod motion to adjust power output in response to load changes yielded an opportunity for a power increase without changing the safety of the design," she said.

When operating to "load follow," the module runs at or below 80% of its potential capacity as it uses these maneuvering techniques to control output. But when operating closer to 100% capacity, the uprated NuScale modules lose some of that flexibility. They cannot adjust their output at the same rates as the lower capacity rated modules, and "hence are better suited for baseload power production," Hughes said.

NuScale says it is currently working on improving the ability of the reactor to operate at full capacity without losing as much of the ability to load follow. "Studies are underway to optimize the core design and operations in a manner that maximizes the load following capability" of the new higher-capacity module, Hughes said.

The NuScale SMR previously had estimated capital costs of $3,600 per kW, but with the capacity uprate, those costs have been reduced to $2,850 per kW for an nth-of-a-kind project, resulting in a capital cost of $2.5 billion for a 924-MW plant, after accounting for electricity used to power the plant's own equipment, according to NuScale. For a first-of-a-kind project, however, NuScale estimates the capital costs to be higher, at $3 billion, which comes out to a little over $3,382 per kW for a 924-MW plant.

The full $6 billion estimate for the CFPP adds in costs of financing the project through construction and its 40-year life, additional plant facilities like cooling systems, inflation and other costs, according to Webb.

How large a project?

The question of exactly how large the project should be has already been at the forefront of UAMPS members' considerations for some time. For a period, the plan was for the DOE to lease one of the 12 modules for the first ten years of operation and use it for research and development at the Idaho National Laboratory, meaning the other owners of the project would not have to cover the costs of building and operating that reactor until DOE's lease was up. But that arrangement has been set aside.

In October, DOE announced a cost sharing award of up to $1.4 billion for the project. That new funding vehicle replaced the previous lease arrangement. As a result, UAMPS members participating in the project would need to pay for power from the first module "earlier than expected," Webb said, though on a cost-sharing basis with the federal government. Some members subsequently withdrew, while other members stayed with the project, but reduced their commitment, such as the municipal utility of Idaho Falls, Idaho, which reduced its share of the CFPP's capacity from 10 MW to 5 MW.

Idaho Falls is trying to strike a balance, the city's mayor, Rebecca Casper, said in an email. "We know there is risk in the development of new technology. There is also potential for enormous benefit and we've tried to balance that out and put protections into our agreement to mitigate those risks. We will consider all of this and any new issues at each off-ramp in the project," she said.

The city's power supply is already 100% carbon-free, so the interest in the CFPP is not driven by regulatory compliance, but rather potential access to non-intermittent clean energy that could be more affordable than alternatives like renewable energy backed up by battery storage, according to Casper. "We are continually watching battery technology closely to see when that becomes reliable and affordable enough, but we aren't there yet," she said.

Following the submittal of the construction and operating license application in 2023, construction of the CFPP is targeted to begin in 2025. In a separate process, the NRC is also considering NuScale's application for certification of the reactor design.