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Pergamon www.elsevier.com/locate/pnucene Progress in Nuclear Energy, Vol. 37, No. 1-4, pp. 5-10, 2000 Published by Elsevier Science Ltd Printed in Great Britain 0149-1970/00/$ - see front matter PII: SO149-1970(00)00016-0 CONSIDERING THE NEXT GENERATION OF NUCLEAR POWER PLANTS GAIL H. MARCUS Principal Deputy Director, Office of Nuclear Energy, Science and Technology U.S. Department of Energy ABSTRACT Nuclear power will be needed for future energy demands, which are expected to grow at different rates around the world. The opportunities for building new nuclear power plants around the world will be depend on need, energy demand growth, and issues related to global warming and climate change. However, four major barriers exist for the expansion of nuclear power: economics, proliferation, safety, and waste. These issues must be addressed in the ongoing research and development of nuclear energy technology and applications. The evolution of nuclear power plant technology is presented as four distinct design generations: (1) prototypes, (2) current operating plants, (3) advanced light water reactor technology, and (4) revolutionary design concepts (i.e., Generation IV) that are now under development. The U.S. DOE Nuclear Energy Research Initiative (NERI) program is focused on the research and development of Generation IV designs that are safe, economic, proliferation-resistant, and will address current waste issues. NERl provides grants for independently peer- reviewed proposals from universities, national laboratories and industry for advanced nuclear research and development. Several NERI projects awarded in 1999 are described in terms of how they remove barriers to nuclear power plant expansion. Another DOE effort, the Accelerator Transmutation of Waste program, will seek to reduce and ameliorate civilian reactor waste. The Accelerator Transmutation of Waste program will involve a six-year science-based research plan to define key technical issues. Finally, the need for international collaboration is stressed for fourth-generation nuclear power technology development. Published by Elsevier Science Ltd. 1. BACKGROUND The next steps in the development and application of nuclear power pose significant challenges for the nuclear power industry. But, the possibility of using nuclear power in the future offers hope for many parts of the world, and bright potential for reactor vendors and the research community. The use of nuclear power has good news and bad news. Characterized in broad terms, the good news about nuclear power today is that our operating

Considering the next generation of nuclear power plants

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Pergamon

www.elsevier.com/locate/pnucene

Progress in Nuclear Energy, Vol. 37, No. 1-4, pp. 5-10, 2000 Published by Elsevier Science Ltd

Printed in Great Britain 0149-1970/00/$ - see front matter

PII: SO149-1970(00)00016-0

CONSIDERING THE NEXT GENERATION OF NUCLEAR POWER PLANTS

GAIL H. MARCUS

Principal Deputy Director, Office of Nuclear Energy, Science and Technology U.S. Department of Energy

ABSTRACT

Nuclear power will be needed for future energy demands, which are expected to grow at different rates around the world. The opportunities for building new nuclear power plants around the world will be depend on need, energy demand growth, and issues related to global warming and climate change. However, four major barriers exist for the expansion of nuclear power: economics, proliferation, safety, and waste. These issues must be addressed in the ongoing research and development of nuclear energy technology and applications. The evolution of nuclear power plant technology is presented as four distinct design generations: (1) prototypes, (2) current operating plants, (3) advanced light water reactor technology, and (4) revolutionary design concepts (i.e., Generation IV) that are now under development. The U.S. DOE Nuclear Energy Research Initiative (NERI) program is focused on the research and development of Generation IV designs that are safe, economic, proliferation-resistant, and will address current waste issues. NERl provides grants for independently peer- reviewed proposals from universities, national laboratories and industry for advanced nuclear research and development. Several NERI projects awarded in 1999 are described in terms of how they remove barriers to nuclear power plant expansion. Another DOE effort, the Accelerator Transmutation of Waste program, will seek to reduce and ameliorate civilian reactor waste. The Accelerator Transmutation of Waste program will involve a six-year science-based research plan to define key technical issues. Finally, the need for international collaboration is stressed for fourth-generation nuclear power technology development. Published by Elsevier Science Ltd.

1. BACKGROUND

The next steps in the development and application of nuclear power pose significant challenges for the nuclear power industry. But, the possibility of using nuclear power in the future offers hope for many parts of the world, and bright potential for reactor vendors and the research community. The use of nuclear power has good news and bad news. Characterized in broad terms, the good news about nuclear power today is that our operating

6 G. H. Marcus

nuclear plants are doing well, in terms of plant capacity, availability and reliability. The bad news is that in many countries, the prospects for building new plants anytime soon are rather low. A small market for nuclear power plants will continue to exist internationally for many years to come. If there is to be a bright future for nuclear power, it is a future that will neither come easy nor through continuing in a business-as-usual fashion.

No one can predict the future of nuclear power; however, many people in industry, academia, and government are beginning to come to some of the same conclusions about the direction nuclear technology must take to have a long-term future. This paper discusses the evolving view of the future, how it tits in the scheme of things, and what should be done to explore it and, if warranted, usher it into reality.

2. THE NEED AND ROLE FOR NUCLEAR POWER

In the United States, nuclear power’s rise from a government research program to a largely successful method of generating baseload electricity was fostered by government policy and a utility industry that worried a lot more about the stable, reliable long-term supply of power than near-term cost. Today and even more so tomorrow, these factors have changed.

Government policy toward nuclear power, in the United States at least, is ambivalent. Today, Government does not encourage or discourage the use of nuclear power. This could change, of course. The issue of global climate change could yet seize the consciousness of the public in a way that could lead to laws and regulations that discourage the burning of fossil fuels to the point that nuclear power becomes more attractive. Many nuclear advocates over the last several years have postulated that nuclear power, long the victim of having all its costs internalized, will ride a wave of carbon taxes to renewed vitality.

While global warming and climate change could someday constitute a clear need for nuclear power in the United States, it is far too early to determine how this issue will impact the prospects of nuclear power. It is pointless to worry about whether future restrictions on carbon or other emissions will tip the cost balance in favor of nuclear power. If nuclear power is an attractive option for utilities, the case must be made without carbon credits or tax incentives. Utilities may not wish to make large, risky investments based on the uncertainties of environmental policy.

Compared to the electric generation industry that entered into nuclear power in the 1960s today’s utility industry has changed dramatically in attitude if not yet as much in form. All utilities must consider short term economic impacts vs. long term benefits. Utility executives that have companies involved in nuclear research and development (R&D) have given a very clear message to the U.S. Department of Energy (DOE) that in the industry, research is something that puts useful technology in the plant after perhaps 18 months of work. Many utilities have difficulties in supporting university nuclear engineering programs in their own service areas. DOE matching dollars to provide grants to university programs have even been unused because utilities do not have the funds or the interest in participating.

Looking to the future, there is a clear opportunity for new nuclear power plants to be built. In the United States, nuclear energy is a vital component of the energy mix, with 104 commercial nuclear power plants producing almost one-fifth of U.S. electricity. Three-fifths of U.S. states rely on nuclear power for a large portion of their electricity requirements. The Energy Information Administration anticipates that, even with aggressive implementation of energy efficiency measures, electricity consumption will increase 1.4 percent every year through 2020. Such increases would at minimum require the building of seven 1 ,OOO-megawatt power plants each year. But during this same period, the EIA projects that approximately 127 gigawatts of existing electric generating capacity will retire because of age, competition, or utility efforts to comply with clean air standards. To replace this lost capacity and meet the estimated growth in demand, the United States will need to build 363

Next generation of nuclear power plants 7

gigawatts of new generating capacity by 2020. There is a clear opportunity here for nuclear power to fill some of this need for electricity.

In the rest of the world, the International Atomic Energy Agency forecasts that electricity demand will grow at an annual rate of less than three percent through 2015. Worldwide growth in electricity demand will be highest in the developing world, particularly among the expanding economies of Asia, where rapid urbanization, industrialization, and population growth have increased demand by almost 50 percent over the past 10 years. Worldwide electric capacity additions are projected to approach 3,503 gigawatts by 2020. An additional 667

gigawatts of power plants have service dates after 2006 or are still in the planning stages. Of this amount, Asian countries will add the largest amount, namely, 367 gigawatts of new electric generating capacity. More than 95 gigawatts of new capacity are scheduled annually over the next three years. The choice of resources for some of this new capacity is limited. Japan, for instance, has little in the way of domestic energy resources. Brazil has now maximized its hydroelectric resources it can responsibly exploit. Prospects for fast growth also exist in Latin American countries such as Brazil and Argentina. Under current plans, of the 659 gigawatts to be added to worldwide electric capacity by 2006, at least 10 percent is expected to be nuclear.

3. U.S. ELECTRICITY GENERATION AND NUCLEAR INDUSTRY TRENDS

Electric utility restructuring is gaining momentum in the United States as competition becomes the practice if not yet the law of the land. This has both positive and negative impacts on the prospects for nuclear power in the U.S. On the positive side, a few years ago doomsayers were predicting the wholesale closure of nuclear power plants in this country. As competitive pressures take hold they have been proven to be wrong. In the United States, nuclear power plants have demonstrated their reliability and high degree of safety and cost effectiveness. The average production costs of nuclear power generation are competitive with the costs of producing electricity from coal, oil, or natural gas, and 6 of every 10 nuclear power plants operating in the United States generated electricity at under 2 cents per kilowatt-hour in a market of 4 to 6 cents per kilowatt-hour.

Furthermore, electric industry restructuring in the U.S. is leading to the consolidation of the nuclear utility industry. Utilities that have proven their ability run their plants safely and cost-effectively are buying nuclear plants from other, smaller utilities to the advantage of both. This development has very positive implications for both the future of current plants and the prospects for future plants.

4. BARRIERS TO FUTURE EXPANSION OF NUCLEAR INDUSTRY

On the negative side, the short-term focus of the utility industry will become even more a factor. Avoiding near-term economic risk will, in many cases, outweigh long-term needs. One clear result of this will be increased reliance on one fuel source (i.e., natural gas) for electricity generation. Using more natural gas is a reasonable decision. For a utility executive who follows this path, there are two advantages: first, that the natural gas is projected to be readily available for many decades; and second, that everyone else is doing it so the executive cannot be singled out for making a bad decision. Utilities are not rewarded for being courageous, and in the foreseeable future, the risks of choosing gas are low. New nuclear plants are not competing against the last generation of nuclear plants or against nuclear plants in Asia. In the United States, nuclear plants must compete against gas.

Besides showing cost-competitiveness, new nuclear plants in the United States and Europe must allay the continued public concerns about safety and nuclear waste, and the Administration’ s concern about nuclear proliferation. These barriers, which have hindered further expansion of nuclear energy using current advanced LWR technology, form the criteria against which we must measure the development of Generation IV nuclear

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technology in order to be successful. This is likely to mean the pursuit of revolutionary nuclear concepts reaching beyond the extrapolation of existing technology.

5. THE EVOLUTION TOWARD GENERATION IV NUCLEAR POWER TECHNOLOGY

The early, rather small Atoms-for-Peace-era plants made up the first generation of nuclear power plants and most are now shut down. [Figure l] The second generation plants represent the vast majority of the nuclear plants now in operation. The third generation is represented by the Advanced Light Water Reactors (ALWRs) that emerged from public-private cooperation in the 1980s and early 1990s. Generation III has been deployed in Japan with the Advanced Boiling Water Reactor, and these reactors have a clear market for the next decade or so, mostly in Asia.

DOE now is in the process of laying the groundwork for Generation IV, a revolutionary reactor technology that is not limited to the extrapolation of existing ALWR technology. More specifically, this means developing plant technologies that alleviate both the proliferation and safety concerns associated with building plants in the developing world while providing U.S. and European utilities with a nuclear option that is competitive with gas. The view that such systems can address the long-term issues holding back nuclear power is gaining increased

prominence.

The Evolution Toward Generation IV Nuclear Power Technology

Earty prototype/

- WERiRBMK

scale - Close relationship wlh

DO” - MuHipk vendors - Custcm des@ns - Size, costs, licensing

times driven up

- Passive safety features

- Standardized designs - Combined license

TMI-2 Chernobyl

I A, A , I I I I b

Figure I

6. A NEW APPROACH TO NUCLEAR ENERGY R&D

The development of a new generation of reactors will necessarily require substantial research and development efforts. As a first step in identifying promising areas for research, DOE initiated a new program in 1999 called the Nuclear Energy Research Initiative (NERI). (Federal Energy Research and Development for the Challenges of the Twenty-First Century, November 1997; Powerful Partnerships: The Federal Role in International Cooperation on Energy Innovation, June 1999). In particular, NERI projects are intended to address the issues

Next generation of nuclear power plants 9

of cost-competitiveness, waste, proliferation resistance, and safety. The NERI program awards modest grants to as many researchers as possible, from all segments of the nuclear research world, in the hope that some of the results will evolve into promising future programs. The research tided under NERI is long-term, supports the vital United States nuclear infrastructure, and features international collaboration to reap new ideas and leverage the grants. All proposals are independently peer-reviewed, and awards are made for up to 3 years in both the fundamental sciences and for design development in selected areas.

DOE issued its first NERI solicitation in October 1998. The agency received 308 proposals and announced 46 awards in May 1999. The 46 R&D awards involved 45 United States organizations, including national laboratories, universities and industry, and 11 foreign R&D partners. Most of the awards were for collaborative projects involving several organizations. DOE plans to fi.md additional projects in the coming years. In addition, DOE expects to initiate specific cooperative assignments with research and countries for jointly funded research in related areas.

The 46 NERI projects now underway address the four main barriers to nuclear expansion in a variety of creative ways. For example:

Options being explored to reduce nuclear power plants include moving from an on-site construction-based approach to a manufacturing mode for building reactors, developing simplified fission reactor designs using direct energy conversion, and developing highly automated monitoring and control for on-line, intelligent self-diagnositc monitoring systems.

NERI is funding three projects that improve proliferation resistance through the use of fuel core designs that would support operation for at least 15 years without fuel shuffling or refueling. Such concepts include designs that are completely sealed and transportable, and that could address the needs of developing countries and supply power to remote locations. Several NERI projects involve advanced fuel concepts that increase proliferation resistance by achieving high bumups and/or the use of thorium.

Current operating reactors are extremely safe as a result of the defense-in-depth philosophy, engineered safety features, procedure-based operations and maintenance approach and strict licensing requirements. But additional design and operating experience invariably leads to new ideas about how to increase safety even further. NERI projects are exploring options such as increasing the degree of passive safety features in the next generation designs, development of reactor designs with extremely low severe-accident risk based on natural effects alone, (i.e., without reliance on engineered safety features), the use of a smart monitoring technique to determine steam generator tube degradation, and the development of a demand-driven nuclear energizer module concept which will achieve demand-driven heat generation without the need for moving parts or working fluids.

To reduce the burden of waste disposal, NERI is tinding new reactor concepts and fuels. Reactor concepts being explored include reactor modules with long-life cores that can retain spent fuel for the life of the reactor. NERI is also funding projects to develop funds that would allow high actinide bumup and that would yield superior waste forms without processing.

Clearly, some of these projects have the potential to help reduce several of the four barriers. The NERI initiatives will help demonstrate which concepts are sufficiently promising for further development.

7. ACCELERATOR TRANSMUTATION OF WASTE (ATW)

While the NERI program looks at ways to improve the waste problem associated with new reactor designs, another way to make the waste problem more manageable is to develop new systems to treat spent fuels such

10 G. H. Marcus

as accelerator transmutation of waste (ATW) and improvement of the spent fuel waste form. An analysis of the high-level nuclear waste produced by commercial nuclear reactors in the form of spent nuclear fuel shows that the most radiotoxic isotopes could be removed from the waste stream by transmutation in a nuclear reactor especially designed for that purpose. This requires processing of the waste, partitioning the isotopes to be transmuted (burned) along with the remaining fissile isotopes, and manufacturing fuel elements out of them. The reactor designed for this purpose is subcritical but would reach criticality through the use of a large

accelerator-driven neutron spallation source. The result would be a waste stream for geologic disposal that is orders of magnitude less radioactive and would no longer be dangerous after several hundred instead of many thousands of years.

DOE recently submitted to the United States Congress the ATW Roadmap, (A Roadmap for Developing Accelerator Transmutation of Waste (ATW) Technology, DOE-RW-05 19, October 1999) which recommends a six-year science-based research program to obtain a better definition of key technical issues, such as the lifetime and reliability of components; the system operational safety and availability characteristics; the performance of the partitioning process in terms of separation achieved for uranium, transuranics and long-lived fission products; and issues involving the performance and waste products of the spallation target and the lead- bismuth coolant loop. If carried forward, this would be a major new program, and would likely be international in scope.

8. GENERATION IV - PATH FORWARD

The NERI awards are an initial step toward the development of fourth-generation nuclear power technologies. More R&D will need to be completed before any of these concepts can move from paper study to technology demonstration. Even more work will be needed to consider whether such systems truly meet the needs of utilities all over the world. There are many questions yet to be answered. Does one size tit all or should different designs be developed for different markets? Can these systems really be cost effective? Can the “manufacturing” approach to nuclear power work in a world with so many competing industrial companies? How would the development costs be paid? Does a new international regulatory process need to be developed? No definitive answers are available at this stage. Clearly, international collaboration will be needed to resolve these questions.

The NERI program offers a vehicle for looking at new ideas from abroad as well as at home. As a further step, the Department organized an international workshop in January 2000 to begin discussion about what needs to happen to develop Generation Four reactors. In the longer run, our hope is that the initiation of research projects under the NERI Program will revitalize of nuclear energy R&D in the United States, and hopefully, around the world.

REFERENCES

1. The NERI concept was first proposed in the President’ s Committee of Advisors on Science and Technology (PCAST) Report of the Energy Research and Development Panel, Federal Energy Research and Development for the Challenges of the Twenty-First Century, November 1997, and Report from the Panel on International Cooperation in Energy Research, Development, Demonstration, and Deployment, Powerful Partnerships: The Federal Role in International Cooperation on Energy Innovation, June 1999 (both on the web at www.whitehouse.gov/WH/EOP/OSTP/html/OSTP_Home.html).

2. Department of Energy, A Roadmap for Developing Accelerator Transmutation of Waste (ATW) Technology, DOE-RW-05 19, October 1999 (available via hard link from the DOE Nuclear Energy home page \~1134;. nti. tli~gov)