In This Issue
Expanding Frontiers of Engineering
December 1, 2002 Volume 32 Issue 4

Licensing and Building New Nuclear Infrastructure

Wednesday, December 3, 2008

Author: Peter S. Hastings

A resurgence of the nuclear industry will require overcoming major challenges.

Electricity demand is outpacing supply growth, and experts have calculated that the United States will need new baseload power generation (including nuclear power generation) by 2010 (NEI, 2002a). As part of the Nuclear Power 2010 Initiative, the U.S. Department of Energy (DOE) established the Near-Term Deployment Group (NTDG) to examine prospects for new nuclear plants in the United States in the next decade. According to a recent study by NTDG, a resurgence of the nuclear industry will be influenced by many factors, including economic competitiveness; deregulation of the energy industry; regulatory efficiency; existing infrastructure; the national energy strategy; safety; management of spent fuel; public acceptance; and nonproliferation (DOE, 2001). NTDG also noted that the nuclear industry is experiencing current shortfalls in several important areas (DOE, 2001):

  • Qualified and experienced personnel in nuclear energy operations, engineering, radiation protection, and other professional disciplines.
  • Qualified suppliers of nuclear equipment and components [including] fabrication capability and capacity for forging large components such as reactor vessels.
  • Contractor and architect/engineer organizations with personnel, skills, and experience in nuclear design, engineering, and construction.
    Nuclear industry infrastructure can be defined in terms of technologies, facilities, suppliers, and regulatory elements; design and operational engineering and licensing tools; and (perhaps most important) human capital to sustain the industry in the near and long terms. NTDG concluded that, although the industry has adequate industrial and human infrastructure today to build and operate a few new nuclear plants, we cannot be sure that this infrastructure can be expanded quickly enough to achieve the goal of 50 GWe in new nuclear plant installed capacity as laid out in the industry’s strategy for the future, Vision 2020 (NEI, 2002a).

The nuclear industry faces infrastructure challenges, untested implementation of new Nuclear Regulatory Commission (NRC) regulations, and uncertainties about the economic competitiveness of new nuclear plants. The near-term deployment of new nuclear-power generation will be a good litmus test of the viability of a larger expansion in nuclear production. According to NTDG, even though the level of additional capacity in the industry goals in Vision 2020 is meager in terms of overall U.S. energy needs, achieving the goal presents major challenges (DOE, 2001).


Industry and Government Initiatives
Various initiatives have been undertaken by the U.S. nuclear industry and DOE to encourage the domestic development of additional nuclear facilities. In 1998, DOE chartered the Nuclear Energy Research Advisory Committee (NERAC) to advise the agency on nuclear research and development (R&D) issues. NERAC released the Long-Term Nuclear Technology R&D Plan in June 2000; NERAC is also responsible for overseeing the development of plans for both NTDG and Generation IV, a project to pursue the development and demonstration of one or more "next-generation" nuclear energy systems that offer advantages in economics, safety, reliability, and sustainability and that could be deployed commercially by 2030 (DOE, 2002). In 1999, DOE initiated the Nuclear Energy Research Initiative (NERI), an R&D program to address long-term issues related to nuclear energy; in 2000, the Nuclear Energy Plant Optimization Program was initiated to focus on the performance of currently operating nuclear plants.


In 2000, NEI formed the industry-wide New Nuclear Power Plant Task Force to identify the market conditions and business structures necessary for the construction of new nuclear power plants in the United States. In April 2001, the task force published the Integrated Plan for New Nuclear Plants, which includes a discussion of nuclear infrastructure (NEI, 2001). More recently, NEI announced Vision 2020, an initiative with a goal of adding 50,000 megawatts of new nuclear generating capacity by 2020, along with increases in efficiency power uprates at existing plants equal to an additional 10,000 megawatts of generating capacity (NEI, 2002b).

DOE funding has recently been allocated to advanced reactor development, specifically for the exploration of government/industry cost sharing for the demonstration of early site permitting as part of new NRC licensing processes (which also include provisions for combined licenses and design certifications) and for national laboratory activities associated with fuel testing, code verification and validation, and materials testing associated with new reactor designs (DOE, 2001).


Technological Infrastructure
A number of elements are required to support a new or existing nuclear plant. Suppliers and fabricators of nuclear fuel and safety-related components are clearly essential, as are suppliers of balance-of-plant equipment, construction materials, electronics and instrumentation, and countless other components.

The U.S. fuel-cycle industry has undergone significant changes in the past few years. Future fluctuations in uranium prices, the deployment of new enrichment technologies, significant consolidation of fuel-cycle supply companies, and the possible recycling of spent fuel could all affect the supply chain for nuclear fuel (i.e., mining/milling, conversion and enrichment, and fabrication into ceramic fuel pellets). The NTDG study recognized the sensitivity of new reactor deployment to these factors. NTDG solicited designs for nuclear plants that could be deployed by 2010 and attempted to identify generic issues that could impede their deployment. Proposals were received from reactor suppliers identifying eight candidate reactor designs. NTDG evaluated these designs to determine the prospects for deployment of a new nuclear plant in the United States by 2010. Candidate reactor technologies were required to demonstrate how they would operate "within credible fuel-cycle industrial structures" assuming a once-through fuel cycle using low-enriched uranium fuel and to "demonstrate the existence of, or a credible plan for, an industrial infrastructure to supply the fuel being proposed." NTDG’s design-specific evaluations concluded that the candidates that would use existing fuel-cycle infrastructure could be built by 2010. However, NTDG also concluded that infrastructure expansion to achieve the industry’s goal of 50 GWe of new installed capacity by 2020 was a "generic gap" that warrants government and industry action (DOE, 2001).

Siting for new reactors will be greatly influenced by how efficiently 10 CFR Part 52 (the NRC regulation for early site permits, standard design certifications, and combined nuclear plant licenses) can be implemented. NTDG concluded that the federal commitment to cost sharing via government/industry partnerships should include a demonstration of the NRC’s early site permit process for a range of likely scenarios. Recently a partnership to evaluate sites for new nuclear plants was announced, and DOE selected three utilities to participate in joint government/industry projects to pursue NRC approval for sites for new nuclear power plants. These projects, the first major elements of DOE’s Nuclear Power 2010 Initiative, are intended to "remove one more barrier to seeing the nuclear option fully revived" in the United States. All three companies intend to seek early site permit approvals that would enable them to locate new, advanced-technology nuclear plants at sites owned by the utilities that currently host commercial nuclear power plants (i.e., Dominion Energy’s North Anna site in Virginia, Entergy’s Grand Gulf site in Mississippi, and Exelon’s Clinton site in Illinois). According to a press release on June 24, 2002, DOE expects applications to be submitted by late 2003.

Design concepts for the waste-management component of fuel-cycle infrastructure were also evaluated by NTDG. Each design concept addressed the on-site storage of spent nuclear fuel; but the current lack of a national system for high-level waste disposal is a programmatic gap common to all new technologies. The Nuclear Waste Policy Act (first passed in 1983, amended many times, and still the subject of heated debate) provides for the development of the Yucca Mountain site in Nevada as a mined, geologic repository for high-level waste and the development of a transportation system linking U.S. nuclear power plants, an interim storage facility, and the permanent repository (NEI, 2002c).

The recycling of spent fuel to recover fissile material and long-lived heavy elements would reduce the heat generation and volume of final waste products. When most existing U.S. nuclear plants were built, the industry - encouraged by the federal government - planned to recycle used nuclear fuel by recovering plutonium. In 1979, however, the United States deferred the reprocessing of all commercial used nuclear fuel because of concerns about the possible proliferation of nuclear weapons. Thus, the industry was forced to adopt a once-through, single-use fuel cycle. Reprocessing and recycling are not currently cost effective in the United States, and most of the discussion about recycling is now focused on increasing the capacity of waste repositories and the transmutation of actinides.

The domestic supply of certain reactor components is another long-term concern. Over time, U.S. capacity for fabricating large components with long lead times (e.g., reactor vessels and steam generators) has diminished. NTDG concluded that in most cases, other countries have the necessary capacity and could support the early expansion of nuclear plant construction in the United States, but domestic capabilities will also have to be reestablished (DOE, 2001). General Electric, for example, has indicated that many of the components and much of the hardware (including pumps, heat exchangers, nuclear fuel, control rods, and some internal reactor components, as well as most balance-of-plant equipment) for its advanced boiling water reactor (ABWR) can be produced in the United States. However, the reactor pressure vessel and the large internal components (the same components used for Japanese and Taiwanese ABWRs) will have to be fabricated by foreign suppliers that have maintained their capacity and expertise for fabricating and machining these large components. Foreign suppliers can and do meet U.S. codes and regulations; most foreign countries follow identical or similar codes, such as ASME Section III, IX, and XI, as well as U.S. NRC-imposed regulations and guidelines. NTDG concluded that this area of infrastructure will have to be reconstituted in the United States for economic reasons and that, for some components (particularly reactor vessels), the existing worldwide capacity may not be adequate to support a large expansion of reactor capacity.

Regulatory Infrastructure
NRC is perhaps best known for regulating reactor construction and operation. The agency also regulates nuclear fuel-cycle operations, including the mining, milling, conversion, enrichment, and fabrication of fuel and waste-management facilities. A number of proposed licensing actions and regulatory initiatives are currently under way at the NRC. The most important in terms of near-term continuity in the nuclear industry and adequate energy supply is the renewal of reactor licenses. NRC regulations limit commercial reactor licenses to an initial 40 years (based on economic and antitrust considerations) but also allow licenses to be renewed (NRC, 2002). The license renewal process involves confirmation that structures, systems, and components can continue to perform safely beyond the original term of the operating license.


License renewal is important for maintaining a significant portion of existing energy production. Currently licensed nuclear reactors generate approximately 20 percent of the electric power produced in the United States. The first plant will reach the end of its original license period in 2006; approximately 10 percent will reach 40 years by the end of 2010; and more than 40 percent will reach 40 years by 2015. As of June 2002, 10 license renewal applications had been granted, and 14 applications were under NRC review; 23 more applications are expected by 2005. License renewal also provides an important collateral benefit by keeping the industry and workforce energized and engaged, thus helping to preserve the institutional and human capital that will be necessary for the near-term deployment of new reactors.

Other high-profile licensing actions related to nuclear industry infrastructure include: an application for a license for a spent-fuel storage facility currently before the NRC and in hearings submitted by Private Fuel Storage (a group of eight electric utility companies in partnership with the Skull Valley Band of Goshute Indians); two pending applications (one from the United States Enrichment Corporation and one from Urenco) for deploying new gas-centrifuge enrichment technologies in the United States; and an application for the construction and subsequent operation of a facility to convert surplus weapons material into commercial fuel as part of an agreement between the United States and Russia to dispose of more than 60 metric tons of surplus plutonium.

A key aspect of regulatory development for near-term deployment is the efficient implementation of 10 CFR Part 52. Created in 1989, this regulation established three new licensing processes for future plants: early site permitting (i.e., NRC approval of a site before a decision has been made to build a plant); design certification (i.e., NRC approval of a standard design); and combined licenses (i.e., a combined construction permit and operating license). These processes could provide a dramatic improvement over the two-step process used for existing U.S. plants. NRC has stated that an application for a combined license that references an early site permit and a certified reactor design could result in an operating license being granted in as little as one year (Jeffrey S. Merrifield, NRC commissioner, remarks to American Nuclear Society Conference, June 7, 1994). In actuality, however, only the design certification process has been demonstrated thus far, and it has taken as long as 10 years.

Not surprisingly, NTDG has called the efficient implementation of 10 CFR Part 52 a high priority for short-term deployment and a matter that requires the attention of industry and government. NTDG recommends that four actions be taken: the expediting of the design certification process; the demonstration of the early site permit and combined license processes; the development of generic guidelines to ensure the efficient, safety-focused implementation of key Part 52 processes; and a demonstration of progress toward a new risk-informed, performance-based regulatory framework (DOE, 2001).

DOE’s recently announced plans to work in partnership with industry to evaluate sites for new nuclear plants will test the early site permitting component of this regulation. DOE proposes that near-term investments be made as part of the Nuclear Power 2010 Initiative, in part to "demonstrat[e] this key NRC licensing process" (DOE press release, June 24, 2002).

Another evolving area of regulatory infrastructure is NRC’s effort to "risk-inform" their regulatory processes. The intent is to improve the regulatory process by incorporating risk insights into regulatory decisions, thereby conserving agency resources and reducing unnecessary burdens on licensees. The risk-informed approach combines risk insights and traditional considerations to focus regulatory and licensee attention on the design and operational issues that are most important to health and safety (NRC, 2001).


In the context of the efficient implementation of 10 CFR Part 52, NTDG calls for a new regulatory framework that is fully risk-informed and performance-based and "go[es] beyond the ongoing efforts to risk-inform 10 CFR Part 50 for current plants" to improve the protection of public health and safety, eliminate regulatory burdens that do not contribute to safety, and "increase the confidence of prospective applicants in the regulatory environment for new plants and encourage business decisions to proceed with new nuclear projects" (DOE, 2001).


Engineering and Licensing Tools
The skills necessary for the development of new infrastructure are largely the same as those necessary for the maintenance of existing facilities. In fact, efforts to continue improving existing facilities not only provide a performance benefit to facility stakeholders, they also help ensure that human and technological resources will be available for the development of new facilities. Thus, ongoing improvements to existing facilities are extremely important. From 1990 to 2000, for instance, improved efficiency at U.S. nuclear power plants provided the production equivalent of constructing 22 new 1,000-MW power plants - enough power to provide 22 percent of new electricity demand during that decade (NEI, 2002d). So, not only are there ample economic reasons for continuing to pursue improvements, there are also substantial collateral benefits, such as ensuring the ongoing development of technological tools and the engagement of human capital in nuclear technologies.


Computer Technology
The most dramatic contributor to changes in design tools in the last 25 years has been computer technology. With today’s computational speeds, optimization and simplification of new plant design and construction seems to be limited only by the imagination. One has only to compare modern development tools to historical methods to appreciate the change.

Core physics simulations provide a good example. In the 1970s, a typical simulation used a lattice-cell code that modeled a single fuel pin (or rod) surrounded by an infinite array of homogenized media created to look like the adjacent pins. Approximations were used to model assembly-averaged thermal-hydraulic effects and axial representations, and in-core fuel management was performed by trial-and-error shuffle schemes, using manual iterations until cycle length and power peaking requirements were met.


Modern design software typically uses a two-dimensional code that models a full fuel assembly and uses advanced ray tracing, collision probability, or Monte Carlo techniques. The core simulator is a three-dimensional advanced nodal code with pin reconstruction techniques and explicit thermal-hydraulic modeling and is capable of three-dimensional space-time calculations. Core-loading pattern development has been automated, using advanced nodal codes coupled with simulated annealing techniques to develop core-loading patterns that meet predetermined limits on pin peaking, cycle length, and other attributes to minimize fuel cost within applicable core physics limits.


Another dramatic example of the benefits of increased computer power is the advent of computer-aided design (CAD) and engineering, which not only have enabled the development of increasingly complex and sophisticated civil/structural models, but have also significantly eased the burden of physical-interference modeling and facility-configuration control. Designs in the 1970s were modeled primarily on paper and required hundreds of individual drawings. Plastic and wooden scale models were often painstakingly fabricated and maintained (Figure 1) to help identify costly interferences between electrical, mechanical, and structural components that could be missed in two-dimensional drawings and to assist with the visualization of designs and changes to those designs.

In the last decade or so, the development of more and more sophisticated models (Figure 2) as the basis of design has improved the coordination of drawings, accelerated the communication of design alternatives, and significantly reduced the requirements for field reworking (Bernstein, 2001). Using a central data representation results in improved integration and coordination among various design documents and between design disciplines. In addition, procurement, construction, and subsequent ongoing configuration-management of the facility - a key aspect of the design, licensing, operation, and maintenance of a nuclear facility - have been greatly facilitated (Bernstein, 2001).


Human Infrastructure
One of the most important aspects of nuclear infrastructure, particularly for a domestic resurgence of the industry, is the development of human resources. The nuclear industry faces the dual challenge of an aging workforce and a growing gap between its employment needs and the number of graduating students. Replacement of the aging workforce is essential for both existing plants and new facilities.


NTDG cited key initiatives dealing with human resources at DOE, NEI, and the American Nuclear Society and recommended that these initiatives be maintained and strengthened (DOE, 2001). On June 10, 2002, DOE announced the establishment of a new program, Innovations in Nuclear Infrastructure and Education, that offers several million dollars in awards to university consortia to encourage investments in programs on research reactors and nuclear engineering and in strategic partnerships with national laboratories and industry. At the same time, DOE announced that it would award more than 100 scholarships, fellowships, and grants to nuclear science/engineering institutions and students.


Other public and private efforts to bolster the educational infrastructure for the nuclear industry are under way throughout the United States. As a result, almost every university and national laboratory associated with nuclear science and engineering now offers scholarships and fellowship programs.

Conclusion
The potential for a resurgence of the nuclear industry in the United States is a function of many factors. New technologies continue to be developed, but key areas of infrastructure to support expansion must be maintained and (in many cases) expanded for a future nuclear option to be sustainable. Although significant challenges lie ahead, a number of government, industry, and joint public/private efforts are under way to facilitate this expansion. The reestablishment of the industrial infrastructure that supplies materials and components, the continued improvement and demonstration of effective regulatory processes, and the development of essential human resources are all critical factors to the future of the nuclear industry in the United States.


Acknowledgments
The author gratefully acknowledges the support and assistance of Dr. Per Peterson (University of California, Berkeley), Richard Clark (Duke Energy), and the Process, Power, and Offshore Division of Intergraph Corporation.

References
Bernstein, P. 2001. 2D to 3D Challenge: Autodesk on Architectural Desktop. London: CADDesk.
DOE (U.S. Department of Energy). 2001. A Roadmap to Deploy New Nuclear Power Plants in the United States by 2010. Washington, D.C.: U.S. Department of Energy.
DOE. 2002. Generation IV website. Available online at:
http://gen-iv.ne.doe.gov.
NEI (Nuclear Energy Institute). 2001. Integrated Plan for New Nuclear Plants. Washington, D.C.: Nuclear Energy Institute.
NEI. 2002a. Vision 2020 Booklet. Available online at: www.nei.org/documents/Vision2020/_Booklet.pdf.
NEI. 2002b. Industry Projects to Build New Nuclear Plants. Available online at: www.nei.org.
NEI. 2002c. National Used Nuclear Fuel Management Program. Available online at: www.nei.org.
NEI. 2002d. Plant Improvement Programs. Available online at: www.nei.org.

NERAC (Nuclear Energy Research Advisory Committee). 2000. Long-Term Nuclear Technology R&D Plan. Washington, D.C.: Nuclear Energy Research Advisory Committee.
NRC (Nuclear Regulatory Commission). 2001. Risk-Informed Regulation Implementation Plan. Washington, D.C.: Nuclear Regulatory Commission.
NRC. 2002. Reactor License Renewal Overview. Available online at: www.nrc.gov/reactors/operating/licensing/renewal/overview. html.
About the Author:Peter S. Hastings is licensing manager at Duke Energy in Charlotte, North Carolina.