Recognizing the growing interest in small modular reactors, EPRI is tracking technical developments in their designs, with an eye toward updating the Utility Requirements Document for new plants.

Interest in small modular nuclear reactors (designs less than about 350 MWe) has evolved from technical curiosity to confirmed utility evaluation in recent years. The potential benefits are numerous, but so are the challenges. EPRI is maintaining technical awareness of the various small modular designs and the unique challenges facing this market, while evaluating the benefits in developing an addendum to the Utility Requirements Document to address their unique design and operational considerations.

	Babcock & Wilcox’s 125 MW mPower design is one of the small modular reactors under development.

Small modular reactors could provide options that don’t currently exist with the larger advanced light water designs. Their smaller output could enable utilities to more closely match capacity additions to demand growth. Their integrated design is small enough to be entirely shop fabricated and shipped to the site to facilitate plant construction. Their lower absolute capital requirements can be spread over a period of time to reduce the financing challenges relative to larger nuclear plants, and revenues generated with the first units can help finance later units.

The challenges are real and encompass regulatory, public perception, and technical issues:

• The modular reactor developers will need sufficient resources (money and people) to complete the designs in a timely fashion, including robust testing programs to meet licensing and owner-operator needs, and completed designs through the first-of-a-kind engineering level (65% to 75% complete engineering).
• A strong utility support base, both at the onset of development and long term, will be needed to demonstrate that small modular reactors can attract reasonable financing and to establish a set of sound utility requirements.
• A public communications campaign will be needed that demonstrates the value and need for both large and small nuclear power plant designs.
• Government and regulatory support will be needed to pursue timely licensing and to coordinate required research.

Anticipating increased member interest in this area, EPRI’s Advanced Nuclear Technology Program, working with the Technology Innovation Program, established an advisory group to assess the need for specific utility requirements with respect to small modular reactors. Because many small modular design features are common to those of operating nuclear plants and the advanced light water reactor designs, many of the existing utility requirements will apply. However, there are many unique technical aspects to the small modular reactors that require upfront consensus by interested owner-operators. The Utility Requirements Document has proven to be a useful tool in ensuring utility desires are clearly articulated and communicated to the designers up front, and in helping utilities establish detailed bid specifications for contracting. Further supporting an objective evaluation of small modular reactors, EPRI’s Energy Technology Assessment Center has future plans to assess the relative economic competiveness of these designs compared with other electricity generation technologies.

While small modular reactors offer a promising approach for deploying clean, competitive nuclear power, additional research and analysis is needed to confirm their commercial viability. For more information, contact Jeff Hamel at 650.855.2095 or jhamel@epri.com.