Staging a comeback

A change in public perception, energy supply concerns and green issues are all driving a nuclear power revival in the US. Technological advances, financial incentives and licence standardisation look set to smooth the process of new build, finds Neil O'Hara

The once-vilified US nuclear power industry is making a comeback. Demand for electricity continues to rise and fast-growing regions like the South and Southwest need more base-load generating capacity. Since the early 1990s, the overwhelming majority of capacity additions relied on what was then cheap and abundant natural gas for fuel – only to face higher costs when the price of gas soared. Renewables can't meet the growing demand alone, so utilities are turning back to nuclear and coal.

The revival means the ghost of Three Mile Island may soon be laid to rest. The 1979 accident gave nuclear energy a bad name in the US and safety regulations adopted in response contributed to serious cost overruns at plants that were under construction at the time. Utilities shelved plans for more reactors – the last new commercial unit to come on line was Tennessee Valley Authority's Watts Bar Plant, which entered service in May 1996.

Since then, the existing nuclear fleet has made significant capacity contributions through power uprates – modifications to existing plants that boost capacity – and a dramatic improvement in operating performance. Energy Information Administration figures show that nuclear generators' capacity factor – the percentage of time plants were in service – rose from 66% in 1990 to almost 90% in 2001 (where it levelled off).

Today's nuclear generating capacity of 100 gigawatts is produced from 104 nuclear reactors and accounts for almost 20% of total US electricity output. The six largest operators – Exelon, Entergy, Dominion Resources, Duke Energy, FPL and Tennessee Valley Authority – own half the plants.

It is unlikely many of these plants will go offline soon. Utilities are preparing to keep the current fleet in service beyond the initial 40-year licences. Some 48 plants have already received a 20-year licence extension and another eight applications are currently pending. It is expected that the entire fleet will consider licence extension and almost all will successfully seek approval from the US federal government's Nuclear Regulatory Commission (NRC).

Despite that, nuclear's 20% share of electricity production is bound to decline now that opportunities for power uprates and improved operating performance at existing plants are largely tapped out.

This adds some urgency to the case for new build. Fortunately for the nuclear industry, the outlook for new build has improved considerably in recent years thanks to advances in technology and a change in the public perception of nuclear.

"We have increased and improved safety performance, we have improved our output and we have improved productivity," says Adrian Heymer, senior director for new plant deployment at the Nuclear Energy Institute (NEI), a Washington DC-based organisation dedicated to promoting nuclear energy, "When you couple that with the uncertainty over fossil fuels and climate change, people begin to look at nuclear in a different light."

Public support reached a low point after the Chernobyl disaster in 1986, when a majority of respondents to the NEI's regular surveys of public opinion opposed nuclear power. In the ensuing 20 years, attitudes have swung to almost 70% in favour in September 2006 among the population at large. The latest survey found even stronger support among the people most directly affected – those who live near existing nuclear plants but do not work there. In the Northeast and Midwest, regions already heavily dependent on nuclear energy, 70% favoured nukes, followed by the South at 67% and 66% in the West.

Local attitudes vary

Local attitudes vary more than the NEI survey suggests, however. Randy Hutchinson, senior vice-president of business development for Entergy Nuclear, which operates 10 nuclear units at eight sites, says the company's plants enjoy strong community support in the South and even at Oswego in upstate New York, where municipal officials have petitioned Entergy to build a second plant.

It's a different story however at Indian Point, which is also in New York state, on the Hudson River near Peekskill.

"Nobody wants it, but they don't know what they would do if it wasn't there," he says. Local residents are equally ambivalent about the Pilgrim plant in Plymouth, Massachusetts, and as for Vermont Yankee near Brattleboro, Vermont – a state famous for its green leanings – Hutchinson says, "I don't think they want anything anywhere in Vermont."

Amid growing concerns about greenhouse gas emissions, some prominent environmentalists who were at one time the most vocal opponents of nuclear power have changed their tune. Last September, Patrick Moore, a founding member of Greenpeace and now head of Greenspirit, a consultancy focused on environmental policy, spoke in favour of nuclear power before the Senate Committee on Energy and Natural Resources. Moore, who once equated nuclear power to nuclear holocaust, testified that "nuclear energy – combined with the use of other alternative energy sources like wind, geothermal and hydro – remains the only practical, safe and environmentally-friendly means of resolving America's energy crisis."

The government is doing its share to encourage new construction, too. The NRC overhauled its licensing process in 1989 to give priority to safety issues and public consultation at the outset, before ground is broken, and to encourage standardisation of reactor designs. Under the old system, utilities got a construction permit and then applied for an operating licence so any required modifications had to be made when the plant was partially built.

"Imagine building a car and halfway through the regulator tells you you have to add a second brake system," says Bryan Dolan, vice-president of nuclear plant development at Duke Energy, which operates seven units at three sites in both North and South Carolina. "It may be technically feasible but you would have liked to have known about it while you had the design on the drawing board."

Now, after an extensive review, the NRC will issue a combined construction permit and operating licence. Provided they adhere to the licence specifications, utilities know before major construction begins they will be free to run the completed plant.

On the legislative front, the Energy Policy Act of 2005 included incentives for the construction of nuclear plants: a production tax credit of 1.8 cents/kWh on up to 6,000 megawatts of capacity for the first eight years of operation, a federal loan guarantee programme for green energy sources from new technologies (which would encompass the latest nuclear reactor designs), and a limited standby support facility to cover the cost of potential construction delays to the first six plants built.

This serendipitous confluence of events has emboldened the power industry to propose new nuclear plants. NEI tallies 19 projects in the early stages, nine of which expect to file formal permit and licence applications in late 2007. The NRC has indicated its review will take up to three years, during which the applicants may do only land clearing and preliminary site work; the first projects won't get a licence to pour concrete for the reactor vessel until 2010.

Heymer, who joined NEI in 1992 after 16 years on nuclear submarines in the Royal Navy and eight years at the Cooper Nuclear Generating Station in Nebraska, anticipates a 48-month schedule to completion, followed by about four months of testing before the NRC gives its final authorisation, probably in 2015.

For new plants, the US industry is trying to emulate successful nuclear programmes in France, Japan and South Korea, where standard designs have fostered the exchange of information among plant operators and improved efficiency, including opportunities to share inventories and spare parts. Nu-Start, an industry consortium of 10 major utilities and two reactor vendors, is working on two advanced models: the General Electric economic simplified boiling water reactor (ESBWR) and the Westinghouse AP1000, in which safety systems depend on gravity, conduction and convection to keep the reactor core cool in an emergency.

Upgrading safety systems

The first generation nuclear plants rely on active safety systems that use pumps and valves to deliver coolant to the core. They require backup diesel generators in case the reactor trips and blocks off site power and depend on redundant overlapping systems to ensure reliability. The advanced designs incorporate elevated water tanks that drain into the core automatically in an emergency and use the reactor's own heat to circulate the water between the core and the tanks. "It's a passive system that operates on natural phenomena," NEI's Heymer says. "It reduces the number of pumps and valves, which tends to increase reliability."

Vaughn Gilbert, a Westinghouse spokesman, says passive safety features cut both capital and operating costs, too. The AP1000 requires fewer pumps, motors and valves (with the associated pipes and wiring) than a conventional design, which means fewer components to test and repair. "The chance of an accident is even more remote than the already remote chance there is now," Gilbert says, "And we are very comfortable with the economics of the plant."

Economics dictate where utilities are choosing to locate the proposed new plants, too: right next to existing plants, in most cases. Community acceptance and an existing skilled workforce play a part, but access to the grid is critical. Entergy chose Grand Gulf, on the Mississippi River near Vicksburg, Mississippi, and River Bend, a few miles downstream in West Feliciana, Louisiana, because both sites were designed to have two units, only one of which was built.

"The single biggest infrastructure cost outside of the reactor plant itself is transmission facilities," says Hutchinson, "The transmission built into the River Bend and Grand Gulf switchyards were for two units. That's a major plus."

Entergy has reaped additional savings by preparing applications in tandem at sites in close proximity; when contractors finish work at Grand Gulf the same crew goes down the road to River Bend.

The industry has taken to heart lessons learned from operating nuclear plants over the past 30 years both in the US and abroad. The Nu-Start consortium is working to standardise as much of an NRC application for each new reactor design as possible. Marilyn Kray, president of Nu-Start, expects an application will consist of about 20 volumes of 4-inch binders, 75-80% of which will be identical; the rest will be site-specific information. "If everybody adheres to that, the NRC will only need to review the identical portion once for each reactor design," she says. If standardisation works as intended, it could cut total project duration on plants after the first wave from 10 years to seven.

In addition to her role at Nu-Start, Kray is vice-president for project development at Exelon, a Chicago-based power company that operates the largest fleet of commercial reactors in the US: 17 units at 10 sites. Kray points out that new nuclear plants will help maintain the diversity of US power generation fuel sources.

Kray is among a select few who have first-hand experience bringing nuclear plants on line: she spent five years as an engineer at the NRC in the mid-1980s working on licence applications for plants that came on stream after Three Mile Island. If the current projects move forward as expected, people with first-hand experience as construction or test engineers will still be around to help commission the new plants. However, says Kray: "If you wait another 10-15 years those people will be retired." The US nuclear revival may be happening just in time.