The nuclear industry has changed. Whereas, in the 1960′s and 1970′s nuclear plant designers built with a “customization to the customer” approach, construction today is based on a “tweaked standard design” approach. Let me explain.
There are but a few basic nuclear steam supply systems. The most utilized versions in the United States are based on a “light water” design, where purified water flows over fuel assemblies in a reactor vessel. Of the 104 operating nuclear reactors in the United States, there are 69 pressurized water reactors (where water in the core never boils) and 35 boiling water reactors (where water in the core boils). But these two designs are hardly the tip of the iceberg of possible nuclear utilization designs.
Prior to 1986, a utility or owner of a proposed plant developed a basic reactor design in consult with a design firm with unique power characteristics and safety systems and submitted an application to the Nuclear Regulatory Commission (NRC, or Atomic Energy Commission, as the regulator was called prior to 1974) to prove its unique plant would not endanger public health and safety. Once a construction permit was issued, each plant was designed in detail as it was built, and the design changed as the plant was constructed in reaction to regulatory order or technological advancement. Regulator-mandated improvements and design enhancements and anti-nuclear intervenors bogged down the licensing and construction process, which led to cost overruns to the tune of billions, prompting utilities to reconsider the financial tenability of their investment. Several projects were scrapped mid construction. Bellefonte 1 & 2 and Perry 2 stand like paperweights beneath the fallout of nuclear agnst, while Marble Hill and Satsop are only failed memories now.
Today’s regulatory regime is different. Designs have been standardized to allow regulatory review of one design, which may then be built on any site whose characteristics are within the design limits. A site is deemed acceptable when its site specific characteristics such as seismicity, flood potential, maximum and minimum ambient temperature, and frequency and severity of inclement weather events and etcetera are proven to be less severe than the characteristics used to test or analyze a certified design. Non-standard portions of the design, which depend on site layout, foundation properties, and heat sink characteristics, are finalized by each utility separately in their Combined License Application.
Licensing a certified design limits the financial risk relatively small utilities incur due to regulatory changes or public intervenors. The public is still allowed the opportunity to challenge the technical merit design certifications, environmental permits, and operating licenses. But the public vetting process occurs once and relatively early in the process, limiting possible impacts to construction.
The current combined licensing regime should not imply that design changes would not be made to improve safety or to fix any technical issues incurred in present designs. Emergent issues, solutions thereof, and any other design changes, are evaluated with regard to their potential impact on the safety and security of the workforce and the public, and licensing amendment requests are made as necessary to meet the notification criteria prescribed in the design certification for each particular design in Part 52 to Title 10 Code of Federal Regulations.
The future of nuclear is bright with promise. Standard design certifications and the streamlined combined licensing process will improve financial certainty for utilities seeking to invest in clean, reliable nuclear energy while preserving the confidence of public safety ensured via regulatory oversight.