PEANuT

Reactor Siting Considerations

Siting allows users to view data relevant to siting advanced nuclear reactors. Areas highlighted in red should be considered inappropriate for siting a reactor. Data were selected according to Oak Ridge National Laboratory's OR-SAGE database and are therefore based on guidelines for siting nuclear reactors in the United States.

Data availability varies by country. All data was acquired by Oak Ridge National Laboratory from authoritative sources.

Airport Locations

The spatial locations of selected airports.

NRC Regulatory Guide 4.7, "General Site Suitability Criteria for Nuclear Power Stations," states that "accidents at nearby industrial facilities, such as chemical plants, refineries, mining and quarrying operations, oil or gas wells, or gas and petroleum product storage installations, might produce missiles, shock waves, flammable vapor clouds, toxic chemicals, or incendiary fragments." These types of facilities and infrastructure should be evaluated for impacts on the nuclear power plant site.

Fault Line Hazards

Land that is too close to identified fault lines. The length of the fault line determines the standoff distance.

10 CFR 100, Appendix A, Table 1 specifies that faults within 200 miles of the site must be considered. The table specifies fault length versus distance from the site that should be considered. OR-SAGE excludes land based on Table 1 and USGS data.

Floodplains

Land that lies within a floodplain.

Executive Order 11988 - Floodplain Management. "Each government agency shall consider alternatives to avoid adverse effects and incompatible development in any floodplain."

Landslide Hazards

Land that is judged by the USGS to have a moderate or high risk of landslide or sinkhole activity. This is a risk projection by the USGS. Highlighted areas are informational and should be evaluated further by an onsite geology inspection. A user may want to evaluate siting results with this layer initially turned off and then subsequently turned on for comparison.

NRC Regulatory Guide 4.7, "General Site Suitability Criteria for Nuclear Power Stations," states that "nuclear power stations must be designed to prevent the loss of safety-related functions. Generally, the most restrictive safety-related site characteristics considered in determining the suitability of a site are surface faulting, potential ground motion and foundation conditions (including liquefaction, subsidence, and landslide potential), and seismically induced floods."

Open Water and Wetlands

Open water includes lakes, rivers, streams, ponds, etc. Wetlands are low-lying ecosystems. They may be shallow open water areas, marshes, swamps, bogs, or fens that teem with a variety of life. In addition, wetlands act as a natural sponge to absorb excess rain to reduce flooding and to retain water to ease periods of drought. Wetlands may be saltwater or freshwater areas.

Open waters are generally protected as a drinking water source, recreational areas, or navigable waterways and not considered for fill to support a reactor site. Open waters requirements and laws can include specific requirements for intake structures for those reactor technologies that require cooling water. Wetlands are often protected by various requirements and laws.

Population Density

Selecting this option will highlight land with a population density greater than 500 people per square mile (ppsm) in concentric 1-mile ring calculations around the OR-SAGE 100m x 100m cell of interest out to the distance indicated for the time frame indicated. Small or advanced technologies can opt to cap the calculation at an alternate distance less than the 20-mile distance recommended by NRC RG 4.7 based on dose calculations associated with a potentially smaller source term. A value of 500 ppsm <10 miles is suggested for larger advanced reactor technologies. A value of 500 ppsm <2 miles is suggested for SMRs and small advanced reactor technologies.

10 CFR 100, "Reactor Site Criteria," addresses a site exclusion area, low population zone, and the distance to a population of greater than 25,000 residents. 10 CFR 100 limits are based on dose to individuals at the site boundary and at the low population zone outer boundary. NRC Regulatory Guide 4.7, "General Site Suitability Criteria for Nuclear Power Stations," states that "a reactor should be located so that, at the time of initial plant approval within about 5 years thereafter, the population density, including weighted transient population, averaged over any radial distance out to 20 mi (cumulative population at a distance divided by the circular area at that distance), does not exceed 500 persons per square mile. A reactor should not be located at a site where the population density is well in excess of this value." SMRs and advanced reactor technologies may have a small source term such that the dose limits of 10 CFR 100 are not exceeded beyond the site boundary allowing closer siting of a reactor while still considering the nearest population center with greater than 25,000 residents. This NRC guidance and associated siting layer is a proxy for dose.

Protected Lands

Land that is within a user defined protected land area.

These lands are excluded because they may be public lands, lands with restricted uses, or access restrictions. NRC Regulatory Guide 4.7, "General Site Suitability Criteria for Nuclear Power Stations," states that locating a nuclear power station adjacent to lands devoted to public use might be unacceptable to local jurisdictions."

Refinery Locations

The spatial locations of selected refinieries.

Seismic Activity

Land with safe-shutdown earthquake (SSE) peak ground acceleration (2% chance in a 50 year return period) between .1g -.6 g. The SSE peak ground acceleration (2% chance in a 50-year return period) greater than the selected threshold parameter value is flagged. This value is variable within the database and can be adjusted based on technology. SSE =0.3 g is suggested for LWRs. SSE =0.5 g is suggested for SMRs.

The 2002 EPRI siting guidance recommended limiting large LWR technologies to less than 0.3 g safe shutdown earthquake peak ground acceleration. As SMRs and advanced reactor technologies allow for more seismic mitigation through design, the OR-SAGE threshold parameter for seismic activity has been set slightly higher at 0.5 g safe shutdown earthquake peak ground acceleration. Mitigating design features may include smaller footprints, smaller piping systems, passive safety systems, underground installation, and improved seismic isolation

Slope

Land with a slope greater than a specified value can increase the costs of preparing a site with slope issues. This threshold value is variable within the database and can be adjusted based on technology and site economics. Slope >12% is suggested for large reactor sites (land with slope greater than 12% will be highlighted). Slope >18% is suggested for SMRs or smaller advanced reactor technologies.

Steeper slopes are avoided based on the economic cost of preparing the site for construction. The 2002 EPRI siting guidance recommended limiting the slope to 12% for large reactor sites. Since small modular reactors and advanced reactor technologies tend to have smaller footprints compared to current large reactors, this value can be relaxed for smaller technologies recognizing that more extensive site work to prepare a relatively small site may be justifiable.