SRNL-L4300-2011-00011 (FINAL).pdf

SRNL-L4300-2011-00011

September 13, 2011

To: Jack Mayer

From: Nancy Halverson

Proposed Site Selection for Small Modular Reactor

Attached is a map showing the results of running the Site Selection Modeling System program (Test #27) for a proposed small modular reactor. To run the program, I had to make a variety of assumptions to fill in the criteria, weighting, and scoring details that a site selection committee would normally decide. Deno Karapatakis and I are still in the process of refining the program. These results should be considered hypothetical since the program has not undergone any verification and the established site-selection procedures were not implemented. This is just a demonstration of what the modeling system can do

The input I used in the program and the resulting maps showing the highest scoring sites are included below.

NuScale's specific criteria were 20 acres Above 100 yr floodplain Seismically stable Possible to dig hole 85 ft deep 4M GPD water required Located near transmission lines Access to roads and rails Access to domestic water Access to sanitary sewer system

I assumed standard ecology and topography criteria apply, also. I assumed the site would be square.

For any given location, Deno rotated the square through 0, 30 and 60 degrees to look for the best orientation.

Exclusions

One specific exclusion was mentioned in project criteria: avoid the 100 yr floodplain. In addition to that, normal exclusion criteria were assumed to apply except the restriction to be a minimum distance away from the site boundary. Exclusions include:

Floodplain buffered at 100m

Threatened and Endangered Species layer buffered at 100m Eagles Nest buffered at 1609m Setasides buffered at 100m Red Cockaded Woodpecker nests buffered at 200m Red Cockaded Woodpecker tracts buffered at 1000m.

Wetlands buffered at 15m Wastesites buffered at 300m Fault lines buffered at 800m Sinkholes buffered to 100m

We do not yet have groundwater contamination plumes entered into the program. I could simply remove any high scoring sites that intersect plumes shown in the current GIS Groundwater Plume Area layer, if you want me to.

Criteria and Weighting

I chose fairly common weightings for the four main categories, using past site selection documents as a guide. Then I chose subcategory weightings. They are as follows:

1. Minimize Ecology Impact (15%)

1.1. Low wetland impact (50%)

1.2. Low aquatic impact (50%)

2. Minimize Human Health Impact (25%) (I had no criteria to use here, so this did not play a factor in the evaluation.

3. Favorable Geoscience Characteristics (25%)

3.1. Seismically stable - distance from fault lines (57%)

3.2. Depth to water table greater than 85 ft (29%)

3.3. Favorable topography (14%)

(i.e. a 4:2:1 ratio for subcategory priorities)

4. Favorable Engineering Characteristics (35%)

4.1. Near power lines (16.7%)

4.2. Near sanitary sewer tie-in (16.7%)

4.3. Near usable roads (16.7%)

4.4. Near railroad (16.7%)

4.5. Near domestic water tie-in (16.7%)

4.6. Can supply 4 MGD water (16.7%)

According to Laura Bagwell, you could access 4 MGD water anywhere on site for the most part. It's just a matter of drilling enough wells or using river water supply. Wells need to be placed in the right aquifers, which are the deeper ones. There would be a difference in how far down you have to drill, but the aquifers do span the whole site. Therefore that criteria did not factor into choosing a site.

Scores for individual criteria were set up as shown in Table 1 below.

Results for the scoring of the whole site are shown in Figure 1, with the highest scoring locations in red and dark red. White areas are exclusion areas. Top scoring sites are shown outlined in green in Figure

2. Green areas that appear to be round are really three separate squares showing the 0, 30 and 60 degree rotation. Note that some dark red areas that seem large enough to host the hypothetical modular reactor were not chosen. This appears to be because they are located such that the predefined grid locations crossed over the areas in a manner that the high scoring territory was split between grid locations. I marked two of these in Figure 2 with blue squares. If this were a real site selection process, SSMS could score these or any other hand selected areas separately to determine whether they score high enough to be considered.

Table 1: Individual Criteria and Scores for Test 27 Run of SSMS for a Hypothetical New Modular Reactor.

Criteria

Distance from GIS feature (m unless noted)

Percentage of maximum score Minimize wetland ecology impact 100 0.2

300 0.6 500 1

Minimize aquatic ecology impact 100 0.2 300 0.6 500 1

Seismically stable - distance from fault lines 1000 0.2 2000 0.4 3500 0.7 5000 1

Maximize depth to groundwater >150 ft 1 125 - 150 ft 0.75 100 - 125 ft 0.5 85 - 100 ft 0.25

Favorable terrain including minimize slope <5 º 1 5 º - 7 º 0.5 7 º - 10 º 0.2

Minimize distance to site utilities-power 1000 1 2000 0.5 3000 0.3 5000 0.15

Minimize distance to site utilities-sewer lines 1000 1 2000 0.5

3000 0.3 5000 0.15

Minimize distance to acceptable road 1000 1 2000 0.5 3000 0.3 5000 0.15

Minimize distance to site rail lines 1000 1 2000 0.5 3000 0.3 5000 0.15

Minimize distance to site utilities-water lines 1000 1 2000 0.5 3000 0.3 5000 0.15

CC. Deno Karapatakis