Big or small, questions about nuclear reactors remain
After years of stalled attempts to build a second large nuclear reactor in Callaway County, Ameren Missouri now wants to change course and install one or more smaller modular reactors on the site.
But while the size and the technology may be different, the players and the arguments for and against such a move are largely the same.
“I’m pretty excited” about the prospect, said William Miller, professor of nuclear engineering at the University of Missouri at Columbia who has long backed additional capacity at the Callaway plant. “This gives new life to additional nuclear power in Missouri.”
He said the small reactors might sacrifice some economies of scale, but they are safer and faster to put online, not to mention cheaper to build.
But Ed Smith of the Missouri Coalition for the Environment said that even though the reactors that could be placed at the site are smaller, the risks they bring, in terms of possible meltdowns and storage of waste, remain the same.
“The environmental impact of a small modular reactor melting down would not be as great as the Callaway reactor melting down,” Smith said, “because it operates at a lower temperature and contains less radioactive material in the fuel rods. But if you have a multiple meltdown of five reactors, you are going to see the same kind of problems in theory as you would have from a large reactor.”
Ameren announced last week it would join with other publicly owned utilities in Missouri to back the Westinghouse Electric Co. in its bid to secure up to $452 million in funds from the federal Department of Energy for engineering, design certification and operating licenses for two designs of the small nuclear reactors, or SMRs.
It said the process not only could lead to the installation of one or more of the reactors at Callaway but could help establish Missouri as the hub of American-made SMR technology.
Ameren said it could be the first utility nationwide to submit an application for a combined construction and operating license for the small reactor, though the utility emphasized that seeking such a license would not necessarily commit it to actually building the plant at Callaway. Officials said it could have as many as five of the reactors on the site.
The application for the federal funds are expected to be submitted by the middle of May, with a final decision on who wins the competitive grants coming this summer.
Proven technology, new design
Officials at Ameren and Westinghouse said the small modular reactor depends on technology that is already proven, but because it is put together in a new way it would require a new license.
If the federal grant money is received, the potential timeline for the project would be submission of design at the end of next year or in 2014, with two or three years for review. Then the application for the combined license would be submitted, with a review period of four years. Finally there would be a construction period of 24 months, so if everything goes as quickly as it can, power could be generated from the plant in 2022.
|Thermal Output||800 MWt|
|Electrical Output||>225 MWe|
|Passive safety systems||No operator intervention required for seven days|
|Reactor vessel size||
Outer diameter: 11.5 ft / 3.5 m
Height: 81.0 ft / 24.7 m
|Upper vessel package||280 tons / 254000 kg|
|Containment vessel size||
Outer diameter: 32.0 ft / 9.8 m
Height: 89.0 ft / 27.1 m
Fully modular construction
|Reactor coolant pumps||
Eight external, horizontally mounted pumps
|Steam generator||Recirculating, once-through, straight-tube|
|Pressurizer||Integral to vessel|
|Instrumentation and control||OVATION®-based digital control system|
In addition to Westinghouse, other companies are developing similar technology, including Holtec and Babcock & Wilcox in the United States and a number of companies overseas. Ameren declined to make anyone available to discuss further why it decided to support Westinghouse’s bid or other questions about the relative merits of the technology.
The Westinghouse SMR is a 225 megawatts reactor, compared with 1,000 megawatts from the current Callaway County reactor. The SMR technology is based on the company’s AP1000 pressured water reactor, whose design has already been licensed by the Nuclear Regulatory Commission. Four of the reactors are being built in China and four more are under construction in the United States, two each in Georgia and South Carolina.
Westinghouse says the reactor relies on passive safety components, to minimize the effects of an accident and possibly eliminate one altogether. In the event that cooling is needed, the company says, water that is already available in the unit can be directed to the area to achieve the task with no outside power required.
Because of their size, Westinghouse and Ameren noted, the units can be manufactured elsewhere, then shipped to their final destination. Such a system reduces construction time and cost and makes nuclear power available in a smaller footprint than with larger reactors.
In terms of the cost of the electricity that the plants produce, the jury is out on whether smaller reactors are a reasonably priced source of power compared with the alternatives.
Warner Baxter, chairman, president and chief executive of Ameren Missouri, said last week that with the expertise available at the Columbia and Rolla campuses of the University of Missouri, he envisions the state being a major player in the design, engineering and manufacturing of small modular reactors.
Pros and cons
Miller, at Mizzou, has been a longtime proponent of expanding nuclear power in Missouri. He echoed Baxter’s sentiment that Ameren has to get away from its large reliance on coal, which now amounts to 76 percent of the fuel used to power its plants, compared with 19 percent nuclear, 1 percent natural gas and 4 percent renewables such as wind and solar.
“Anything we can do to move away from that makes sense,” Miller said of the dependence on coal, “and nuclear is a big part of that.”
He said that Missouri is not well situated for wind power, despite some use of it in the northwest corner of the state, and solar is good only for peak demand, not for electricity 24/7.
He also noted that the small modular reactors, located totally below ground, have a better potential for safety than larger reactors such as the one operating at Callaway now.
“If Callaway has a problem,” he said, “you’ve got to provide cooling to the reactor within hours of it being shut down. And you have to have power to do that, either electricity from offsite or emergency generators onsite to keep it cool.
“Passive means you can push an off button and walk away, turn off all the power and not worry about it. This thing will cool itself passively without any active intervention. Its size makes that possible.”
Despite the problems at the Fukushima reactor in Japan after last year’s earthquake and tsunami, Miller said nuclear energy is “one of the safest sources of power we have. That has been demonstrated over and over again. I don’t want to minimize what happened in Japan. That has been a tragedy. But no one from the public or even the operators of the plant will have health problems at all.”
One potential problem Miller did envision with a smaller reactor is security.
“I’ve always been puzzled by security issues,” he said. “Callaway has a barbed wire fence and ultrasound and people with guns that is part of our safety situation after 9/11. With smaller reactors, there is talk about shipping them across the country and the world. So we would have to have more security to do that.
“I’m not sure everyone has thought through what security would be for an isolated small reactor. It might not affect what would be going on here in Missouri, but if the idea is that you can go into a third-world country and start putting in small reactors, security costs could be pretty high.”
To CWIP or not to CWIP
Another question of cost is the long-running debate over CWIP – allowing utilities to charge customers the cost of construction works in progress before they generate any power. Since a voter initiative passed in 1976, the practice has been banned in Missouri, despite periodic attempts in Jefferson City to overturn the ban.
Baxter said last week that because of the alliance backing the Westinghouse effort to win federal funds, efforts to overturn the ban on CWIP are on hold for now.
But, he told reporters, to move forward and actually build new facilities at Callaway, “we do believe that the regulatory framework would have to be enhanced to support this long-term investment.”
Baxter added that overturning the ban on CWIP could have long-term cost savings for customers, but that route would not be the only way that Ameren could pay for the license and construction of the plant.
Smith, with the Coalition for the Environment, said that such action would end up penalizing ratepayers with a cost that should be borne by Ameren's shareholders. He said lawmakers and other public officials who back a repeal of the ban on CWIP do not have the best interests of Missouri customers at heart.
“It’s mind-numbing,” he said. “They have trampled on renewable energy and efficiency. It reminds me of spoiled kids in the candy store who can’t get their way, and Jay Nixon is the parent who says OK, we’ll charge ratepayers all you want.
“When Warner Baxter says Ameren is going to need an ‘enhanced regulatory framework’ for this, that is code for saying we need to repeal consumer protection. Screw the environmental consequences for a moment. More people are concerned about how am I going to afford this?”
Not that Smith takes safety or environmental concerns lightly.
“Nuclear engineers cannot build anything that is 100 percent passive,” he said. “If something goes wrong with a small modular reactor, you’re going to need to have humans come in and try to fix the problem. There is no such thing as creating radioactive waste that is going to last a million years, putting it in a metal container and saying everything is going to be all right.”
He prefers other ways for Ameren to reduce its dependency on coal-fired plants.
“The sure bet is energy efficiency and renewable energy,” Smith said. “But Ameren doesn’t want a sure bet for its ratepayers. It is looking for a sure bet for its shareholders at the expense of its ratepayers.”
To emphasize its opposition to nuclear power in general, not just the small modular reactors, the Coalition for the Environment announced Wednesday that it is filing a legal challenge to Ameren’s proposal to extend the operating license of its current Callaway County plan by 20 years.
In a filing with the Nuclear Regulatory Commission, the coalition said it was concerned that lessons learned from the Japanese nuclear meltdown have not been applied at Callaway.
Its objections contended that wind energy can meet demand more efficiently over the next 20 years and that Ameren needs to evaluate the environmental impacts of a range of modifications that would protect the Callaway reactor in an accident similar to the one that struck the Japanese plant last year.
“Our longstanding concern, in regards to the Callaway nuclear reactor, has been one of public safety and the protection of our environment,” Smith said in a statement. “At the very least, we want to ensure that lessons learned from the Fukushima triple reactor meltdown are rigorously applied before Callaway is granted a license extension.”