United States Nuclear Regulatory Commission - Protecting People and the Environment

NRC: Generic Environmental Impact Statement for License Renewal of Nuclear Plants (NUREG-1437 Supplement 2, Part 9)

4.0 Environmental Impacts of Operation



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Section Contents

Environmental issues associated with operation during the renewal term were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996a; 1999a). The GEIS included a determination of whether the analysis of the environmental issues could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

(1) the environmental impacts associated with the issue have been determined to apply either to all plants or, for some issues, to plants having a specific type of cooling system or other specified plant or site characteristics

(2) a single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the impacts (except for collective offsite radiological impacts from the fuel cycle and from HLW and spent fuel disposal)

(3) mitigation of adverse impacts associated with the issue has been considered in the analysis, and it has been determined that additional plant-specific mitigation measures are likely not to be sufficiently beneficial to warrant implementation.

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that did not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

This chapter addresses those issues related to operation during the renewal term that are listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1 that are applicable to ONS. Section 4.1 addresses the Category 1 issues applicable to the ONS once-through cooling system, while Category 2 issues applicable to the ONS cooling system are discussed at greater length in Sections 4.1.1 through 4.1.4. Section 4.2 addresses Category 1 issues related to transmission lines and land use, while Category 2 issues are discussed in Sections 4.2.1 and 4.2.2. Section 4.3 addresses the radiological impacts of normal operation. There are no Category 2 issues related to radiological impacts of normal operation. Section 4.4 addresses the Category 1 issues related to the socioeconomic impacts of normal operation during the renewal term. Category 2 socioeconomic issues are discussed in Sections 4.4.1 through 4.4.6. Section 4.5 addresses the Category 1 issues related to groundwater use and quality. Category 2 groundwater use and quality issues are discussed in Sections 4.5.1 and 4.5.2. Section 4.6 discusses the impacts of renewal-term operations on threatened and endangered species, a Category 2 issue. Section 4.7 addresses new information that was raised during the scoping period. The results of the evaluation of environmental issues related to operation during the renewal term are summarized in Section 4.8. Finally, Section 4.9 lists the references for Chapter 4.

4.1 Cooling System

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS cooling system operation during the renewal term are listed in Table 4-1. Duke stated in its environmental report (ER) (Duke 1998a) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of the issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

  • Altered current patterns at intake and discharge structures: Based on information in the GEIS, the Commission found that "Altered current patterns have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information, including reports of studies of Lake Keowee performed for the South Carolina Department of Health and Environmental Control (SDCHEC). Therefore, the staff concludes that there are no impacts of altered current patterns during the renewal term beyond those discussed in the GEIS.
  • Altered thermal stratification of lakes: Based on information in the GEIS, the Commission found that "Generally, lake stratification has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including reports of studies of Lake Keowee performed for the SCDHEC. Therefore, the staff concludes that there are no impacts of altered thermal stratification of Lake Keowee during the renewal term beyond those discussed in the GEIS.

Table 4-1. Category 1 Issues Applicable to the Operation of the ONS Cooling System During the Renewal Term

ISSUE--10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Sections

Surface Water Quality, Hydrology, and Use (for all plants)

Altered current patterns at intake and discharge structures 4.2.1.2.1; 4.3.2.2; 4.4.2
Altered thermal stratification of lakes 4.2.1.2.3; 4.4.2.2
Temperature effects on sediment transport capacity 4.2.1.2.3; 4.4.2.2.
Scouring caused by discharged cooling water 4.2.1.2.3; 4.4.2.2
Eutrophication 4.2.1.2.3; 4.4.2.2
Discharge of chlorine or other biocides 4.2.1.2.4; 4.4.2.2
Discharge of sanitary wastes and minor chemical spills 4.2.1.2.4; 4.4.2.2
Discharge of other metals in waste water 4.2.1.2.4; 4.3.2.2; 4.4.2.2
Water-use conflicts (plants with once-through cooling systems) 4.2.1.3

Aquatic Ecology (for all plants)

Accumulation of contaminants in sediments or biota 4.2.1.2.4; 4.3.3; 4.4.3; 4.4.2.2
Entrainment of phytoplankton and zooplankton 4.2.2.1.1; 4.3.3; 4.4.3
Cold shock 4.2.2.1.5; 4.3.3; 4.4.3
Thermal plume barrier to migrating fish 4.2.2.1.6; 4.4.3
Distribution of aquatic organisms 4.2.2.1.6; 4.4.3
Premature emergence of aquatic insects 4.2.2.1.7; 4.4.3
Gas supersaturation (gas bubble disease) 4.2.2.1.8; 4.4.3
Low dissolved oxygen in the discharge 4.2.2.1.9; 4.3.3; 4.4.3
Losses from predation, parasitism, and disease among organisms exposed to sublethal stresses 4.2.2.1.10; 4.4.3
Stimulation of nuisance organisms 4.2.2.1.11; 4.4.3

Human Health

Microbial organisms 4.3.6
Noise 4.3.7
  • Temperature effects on sediment transport capacity: Based on information in the GEIS, the Commission found that "These effects have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of temperature effects on sediment transport capacity during the renewal term beyond those discussed in the GEIS.
  • Scouring caused by discharged cooling water: Based on information in the GEIS, the Commission found that "Scouring has not been found to be a problem at most operating nuclear power plants and has caused only localized effects at a few plants. It is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of scouring during the renewal term beyond those discussed in the GEIS.
  • Eutrophication: Based on information in the GEIS, the Commission found that "Eutrophication has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including plant monitoring data and technical reports. Therefore, the staff concludes that there are no impacts of eutrophication during the renewal term beyond those discussed in the GEIS.
  • Discharge of chlorine or other biocides: Based on information in the GEIS, the Commission found that "Effects are not a concern among regulatory and resource agencies, and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharge of chlorine or other biocides during the renewal term beyond those discussed in the GEIS.
  • Discharge of sanitary wastes and minor chemical spills: Based on information in the GEIS, the Commission found that "Effects are readily controlled through the NPDES permit and periodic modifications, if needed, and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharges of sanitary wastes and minor chemical spills during the renewal term beyond those discussed in the GEIS.
  • Discharge of other metals in waste water: Based on information in the GEIS, the Commission found that "These discharges have not been found to be a problem at operating nuclear power plants with cooling-tower-based heat dissipation systems and have been satisfactorily mitigated at other plants. They are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharges of other metals in waste water during the renewal term beyond those discussed in the GEIS.
  • Water-use conflicts (plants with once-through cooling systems): Based on information in the GEIS, the Commission found that "These conflicts have not been found to be a problem at operating nuclear power plants with once-through heat dissipating systems." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of available information. Therefore, the staff concludes that there are no water-use conflicts during the renewal term beyond those discussed in the GEIS.
  • Accumulation of contaminants in sediments or biota: Based on information in the GEIS, the Commission found that "Accumulation of contaminants has been a concern at a few nuclear power plants but has been satisfactorily mitigated by replacing copper alloy condenser tubes with those of another metal. It is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of available information. Therefore, the staff concludes that there are no impacts of accumulation of contaminants in sediments or biota during the renewal term beyond those discussed in the GEIS.
  • Entrainment of phytoplankton and zooplankton: Based on information in the GEIS, the Commission found that "Entrainment of phytoplankton and zooplankton has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including reports by Hudson and Nichols (1978) and Duke (1977). Therefore, the staff concludes that there are no impacts of entrainment of phytoplankton and zooplankton during the renewal term beyond those discussed in the GEIS.
  • Cold shock: Based on information in the GEIS, the Commission found that "Cold shock has been satisfactorily mitigated at operating nuclear plants with once-through cooling systems, has not endangered fish populations or been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds, and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including Barwick et al. (1995). Therefore, the staff concludes that there are no impacts of cold shock during the renewal term beyond those discussed in the GEIS.
  • Thermal plume barrier to migrating fish: Based on information in the GEIS, the Commission found that "Thermal plumes have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including information from Oliver and Hudson (1987). Therefore, the staff concludes that there are no impacts of thermal plumes during the renewal term beyond those discussed in the GEIS.
  • Distribution of aquatic organisms: Based on information in the GEIS, the Commission found that "Thermal discharge may have localized effects but is not expected to affect the larger geographical distribution of aquatic organisms." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational reports by Oliver and Hudson (1987), Barwick (1984), and Barwick et al. (1995). Therefore, the staff concludes that there are no impacts on the distribution of aquatic organisms during the renewal term beyond those discussed in the GEIS.
  • Premature emergence of aquatic insects: Based on information in the GEIS, the Commission found that "Premature emergence has been found to be a localized effect at some operating nuclear power plants but has not been a problem and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational studies reported by Oliver and Hudson (1987). Therefore, the staff concludes that there are no impacts of premature emergence of aquatic insects during the renewal term beyond those discussed in the GEIS.
  • Gas supersaturation (gas bubble disease): Based on information in the GEIS, the Commission found that "Gas supersaturation was a concern at a small number of operating nuclear power plants with once-through cooling systems but has been satisfactorily mitigated. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of gas supersaturation during the renewal term beyond those discussed in the GEIS.
  • Low dissolved oxygen (DO) in the discharge: Based on information in the GEIS, the Commission found that "Low dissolved oxygen has been a concern at one nuclear power plant with a once-through cooling system but has been effectively mitigated. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational studies conducted by Oliver and Hudson (1987) and the 316(a) demonstration report (Duke 1995). Therefore, the staff concludes that there are no impacts of low dissolved oxygen during the renewal term beyond those discussed in the GEIS.
  • Losses from predation, parasitism, and disease among organisms exposed to sublethal stresses: Based on information in the GEIS, the Commission found that "These types of losses have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of losses from predation, parasitism, and disease among organisms exposed to sub-lethal stresses during the renewal term beyond those discussed in the GEIS.
  • Stimulation of nuisance organisms: Based on information in the GEIS, the Commission found that "Stimulation of nuisance organisms has been satisfactorily mitigated at the single nuclear power plant with a once-through cooling system where previously it was a problem. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the 316(a) demonstration report (Duke 1995). Therefore, the staff concludes that there are no impacts of stimulation of nuisance organisms during the renewal term beyond those discussed in the GEIS.
  • Microbiological organisms (occupational health): Based on information in the GEIS, the Commission found that "Occupational health impacts are expected to be controlled by continued application of accepted industrial hygiene practices to minimize worker exposures." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of microbiological organisms during the renewal term beyond those discussed in the GEIS.
  • Noise: Based on information in the GEIS, the Commission found that "Noise has not been found to be a problem at operating plants and is not expected to be a problem at any plant during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of noise during the renewal term beyond those discussed in the GEIS.

Category 2 issues related to cooling system operation during the renewal term that are applicable to ONS are discussed in the sections that follow. These issues are listed in Table 4-2.

Table 4-2. Category 2 Issues Applicable to the Operation of the ONS Cooling System During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Sections 10 CFR 51.53(c)(3)(ii) Subparagraph SEIS Section

Aquatic Ecology (for plants with once-through and cooling pond heat dissipation systems)

Entrainment of fish and shellfish in early life stages 4.2.2.1.2; 4.4.3 B 4.1.1
Impingement of fish and shellfish 4.2.2.1.3; 4.4.3 B 4.1.2
Heat shock 4.2.2.1.4; 4.4.3 B 4.1.3
Microbiological organisms (human health) 4.3.6 G 4.1.4

4.1.1 Entrainment of Fish and Shellfish in Early Life Stages

For plants with once-through cooling systems, entrainment of fish and shellfish in early life stages into cooling water systems associated with nuclear power plants is considered a Category 2 issue, requiring a site-specific assessment before license renewal.

The staff reviewed NPDES Permit #SC0000515 (that governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee Hydro Station's tailrace). The current permit was issued on September 29, 1999, and expires on September 30, 2003.

The EPA-issued NPDES permit effective February 18, 1975, required Oconee to implement a program to monitor entrainment through plant intake structures in accordance with Section 316(b) of the Federal Water Pollution Control Act (FWPCA), also known as the Clean Water Act. Rates of entrainment were studied and summarized in a letter report to the EPA on March 24, 1976 (letter from W.D. Adair, 1976, in Duke 1999a). The summary report, which Duke considers its 316(b) demonstration, indicated that no fish eggs or larvae were collected after extensive sampling that began in May 1973.

While no formal record of acceptance by the EPA of this 316(b) demonstration has been identified, the EPA did issue a modified NPDES permit on August 30, 1976, that deleted requirements to monitor entrainment through plant intake structures (Duke 1998a). No further studies or analyses were required in subsequent NPDES permits.

However, while the EPA was reviewing the 316(b) demonstration report, Duke was conducting additional larval entrainment studies weekly from March through August 1976 to document the efficiency of the skimmer wall to reduce entrainment of larval fish (Olmsted and Adair 1981). Standing crops of fish larvae in the intake canal and in Lake Keowee were compared to numbers of fish larvae entrained under the skimmer wall and through the condensers. Overall, the density of fish larvae entrained was always less than 1 percent of that noted in concurrent lake sampling at ONS. The difference in larvae densities between the lake and intake canal was attributed to the skimmer wall's depth being below the thermocline during the spawning season. Thus, this study served to reinforce the results of the 316(b) demonstration.

On March 2, 1979, the staff issued Amendments to the Licenses for Oconee Units 1, 2, and 3 that deleted the aquatic surveillance and special studies programs because the Environmental Impact Appraisal performed for this amendment concluded the impact of Oconee on the aquatic environment was within the bounds of the final environmental statement (FES) and that the special study programs were no longer necessary (letter from R.W. Reid, March 1979 in Duke 1999a).

The staff has reviewed the available information relative to potential impacts of the cooling water intake system's entrainment of fish and shellfish in early life stages. Based on this review, the staff has concluded that the potential impacts are SMALL, and mitigation is not warranted.

4.1.2 Impingement of Fish and Shellfish

For plants with once-through cooling systems, impingement of fish and shellfish on debris screens of cooling water systems associated with nuclear power plants is considered a Category 2 issue, requiring a site-specific assessment before license renewal. Impingement of shellfish is not an issue because there is no significant population of endemic shellfish species in the vicinity of ONS (Duke 1999b).

The staff reviewed NPDES Permit #SC0000515, which was issued on September 29, 1999, and expires on September 30, 2003. This permit governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee River (at the location of the Keowee Hydro Station's tailrace).

An early EPA-issued NPDES permit effective February 18, 1975, required Oconee to implement a program to monitor impingement of fish on plant intake structures in accordance with Section 316(b) of the Clean Water Act. Rates of impingement were studied and summarized in a letter report to the EPA on March 24, 1976 (letter from W.D. Adair 1976 in Duke 1999a). The summary report indicated that

    ...impingement of game and sport fish has been low. Small bluegill and yellow perch were the fishes most commonly impinged prior to the introduction of threadfin shad into Lake Keowee. Since threadfin have become established, we have a situation which is typical of cooling reservoirs in the southeastern U.S. Threadfin comprise the majority of those fish impinged (over 90 percent on most occasions) and contribute most to seasonal trends - i.e., high impingement rates in winter and low in summer. In view of the species and number of fishes affected it is doubtful that impingement at Oconee exerts any significant impact on resident fish populations of Lake Keowee.

These findings on impingement were drawn largely from a study conducted by Duke (Edwards et al. 1976) that determined the number of finfish impinged on stationary screens at Oconee Nuclear Station between July 1974 and May 1975. Six screens (two screens per unit and 25 percent of total screen area) were removed and inspected at 2-week intervals. Over the entire study period, 241,697 fish were collected on representative screens.

Overall, species composition found impinged during the study included threadfin shad, Dorosoma petenense (49.3 percent), yellow perch, Perca flavescens (2.5 percent), and bluegill, Lepomis macrochirus (1.4 percent), even though threadfin shad were only introduced to Lake Keowee in February 1974 and did not show up in impingement samples until November 1974. Many fish collected during the study were unidentifiable (46.8 percent), but were suspected to be almost entirely threadfin shad (Duke 1998a, Attachment B), and the remainder were miscellaneous species that comprised an insignificant portion of the impingement samples.

SCUBA divers inspected all 24 screens at ONS between September 16 and 19, 1974, to ensure that impingement rates were similar for all screens and that subsampling at representative screens from each unit was realistic for estimating total impingement. Significant differences among screens was not apparent (Duke 1998a, Attachment B). Electrofishing, gill-net, and rotenone data were used to compare species composition throughout the lake to species found on intake screens. All species collected on the intake screens were represented in field collection samples, but 33 species collected in the field were not observed on intake screens. This suggests that susceptibility to impingement was, in part, species specific.

Impacts from impingement are determined relative to recreationally or commercially important species. A creel census conducted in 1973 indicated that largemouth bass (Micropterus salmoides), bluegill, and crappie (Pomoxis spp.) were the most important sport fish taken from Lake Keowee. Data on angler effort and harvest rates collected over a period from 1974 to 1993 (Barwick et al. 1995) confirmed that largemouth bass remained the most important sportfish in the reservoir and that sunfish (Lepomis spp., including bluegill) and crappie were the only other species that contributed in a significant way to the reservoir's sport fishery. Sampling conducted from 1972 to 1993 indicated that these species were also the most common sportfish in the reservoir (Duke 1995). Occasional impingement of these species is not expected to produce population-level effects. Again, only 1.4 percent of fish impinged in the 1974-75 study (Edwards et al. 1976) were bluegill. Other sunfish species, largemouth bass, and crappie were included in the "miscellaneous" category that made up less than 0.3 percent of the total fish impinged. Threadfin shad were the most frequently impinged species (49.3 percent). They are a forage fish species and are not considered important by either recreational or commercial standards.

Over the years, NPDES permits issued to Duke for ONS gradually reduced requirements for evaluating impingement because research indicated that important aquatic species were not being adversely impacted. No correspondence could be located indicating EPA's formal approval of the study. However, the EPA issued a modified NPDES permit on August 30, 1976, that deleted requirements to monitor impingement through plant intake structures (Duke 1998a). No further studies or analyses were required in subsequent NPDES permits. On March 2, 1979, the staff issued Amendments to the Licenses for Oconee Units 1, 2, and 3 that deleted the aquatic surveillance and special studies programs because the Environmental Impact Appraisal performed for this amendment concluded that the impact of Oconee on the aquatic environment was within the bounds of the FES and that the special study programs were no longer necessary (letter from R.W. Reid, March 1979 in Duke 1999a).

Although special studies were no longer required, additional impingement studies were performed from January through March 1990 (Barwick 1990). During this period of weekly sampling, only three fish species were found in impingement samples, none of which are considered important sportfish species. Threadfin shad comprised 91.5 percent of the total fish impinged, blueback herring (Alosa aestivalis) comprised 8.4 percent, and yellow perch comprised 0.1 percent. The numbers of fish impinged were 2.6 times the number of impinged fish that were reported by Edwards et al. (1976) and were estimated to represent 11.1 percent of the pelagic fish population in the Keowee Reservoir. Although threadfin shad are not commercially or recreationally important, the high rate of impingement merits some discussion. Mobile hydroacoustic surveys conducted during spring and fall 1989, 1990, 1996, and fall 1997 show a pattern in threadfin shad population dynamics that helps explain the high percentage of impinged fish (Duke 1999a).

Table 4-3 (Duke 1999a) shows the fluctuation in pelagic fish populations (approximately 51 percent threadfin shad and 49 percent blueback herring) between spring and fall surveys.

Table 4-3. Fluctuation in Pelagic Fish Populations Between Spring and Fall Surveys

Numbers of Small Pelagic Fish (millions) Date of Mobile Hydroacoustic Survey
3.0 March 1989
4.9 November 1989
2.6 March 1990
14.1 November 1990
12.5 March 1996
28.2 November 1996
3.7 November 1997

The estimated numbers of small pelagic fish are always lower in spring than fall, following a period of high winter mortality. Blueback herring are not overly susceptible to cold temperatures, but threadfin shad become stressed at temperatures less than 10C (50F) and exhibit complete mortality at 4C (39F) (Griffith 1978). Areas of Keowee Reservoir often drop below 10C (50F) during the winter, severely weakening large numbers of threadfin shad that die or become stressed and unable to resist intake currents. According to the seasonal study conducted by Edwards et al. (1976), 88 percent of all threadfin shad impingement at Oconee occurred between January and March. However, as indicated by the hydroacoustic survey results showing seasonal population fluctuations, threadfin shad have a high fecundity and generally expand their population considerably by fall so long as an adequate number of spawners survived the winter. Edwards et al. (1976) concluded that "the impingement of threadfin shad at (Oconee) does not appear to be a major cause of mortality but is rather an indication of natural mortality of the species."

Based on these data, the staff has reviewed the available information relative to potential impacts of the cooling water intake system on the impingement of fish and shellfish, and concludes that the potential impacts are SMALL, and mitigation is not warranted.

4.1.3 Heat Shock

For plants with once-through cooling systems, the effects of heat shock are listed as a Category 2 issue and require plant-specific evaluation before license renewal.

The staff reviewed NPDES Permit #SC0000515, which was issued on September 29, 1999, and expires on September 30, 2003 (as discussed in Section 4.1.1). This permit governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee River at the location of the tailrace to the Keowee Hydro Station.

The staff also reviewed the results of a 316(a) demonstration that Duke submitted in January 1995 (Duke 1999a). Based on the study, the SCDHEC granted a 316(a) variance. Duke submitted a reapplication in March 1998 and supporting documentation in May 1998 to the SCDHEC requesting a continuation of the variance.

ONS complies with State standards and has an approved NPDES permit and 316(a) variance. Under such circumstances, pursuant to 10 CFR 51.53(c)(3)(ii)(B), no further assessment of heat shock is required. Thus, the staff concludes that potential heat shock impacts resulting from operation of the plant's cooling water discharge system to the aquatic environment on or in the vicinity of the site are SMALL, and mitigation is not warranted.

4.1.4 Microbiological Organisms (Human Health)

For plants discharging cooling water to cooling ponds, lakes, canals, or small rivers, the effects of microbiological organisms on human health are listed as a Category 2 issue and require plant-specific evaluation before license renewal.

ONS has a once-through cooling system that uses Lake Keowee as the cooling source. The Keowee and Little Rivers were impounded to form Lake Keowee. The combined flow rate for the Keowee and Little Rivers is lower than the 9 × 1010 m3 per year (3.15 × 1012 ft3 per year) specified in 10 CFR 51.53(c)(3)(ii)(G). This low flow rate raises a concern from the standpoint of the potential for enhancement of thermophylic microorganisms such as Naegleria fowleri. This type of organisms could be a potential health concern for members of the public swimming in the cooling source (Duke 1998a).

Although Lake Keowee is a popular site for water-based recreational activities, including swimming and water skiing, these activities are dispersed throughout the lake, rather than being concentrated in specific areas such as near the plant. In addition, the nearest private pier located on the Keowee River arm of the lake is 1300 m (4200 ft) from the discharge structure.

In a letter included with the ER (Duke 1998a), the State toxicologist at the SCDHEC indicated that there "seems to be no significant threat to off-site persons near such heated recreational waters [from operation of ONS] ."

Although there is a potential for deleterious thermophylic microorganisms to be associated with the cooling system, the actual hazard to public health has not been documented or substantiated. The results of analyses and evaluations, including the results of consultation with the State Public Health Department, indicate that the impact of deleterious microbiological organisms during continued operation of the plant during the renewal term are expected to be SMALL, and mitigation is not warranted.

4.2 Transmission Lines

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The FES discussed five transmission lines with a total length of 528 km (330 mi) that connect the plant to the Duke Energy Transmission System. They were constructed concurrently with the construction of Oconee and the Keowee-Toxaway Project and connect both Oconee and the Keowee-Toxaway Project hydro plants to the Duke Energy Transmission System.

Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to the ONS transmission lines are listed in Table 4-4. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-4. Category 1 Issues Applicable to the ONS Transmission Lines During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1

GEIS Section

Terrestrial Resources

Power line right-of-way management (cutting and herbicide application) 4.5.6.1
Bird collisions with power lines 4.5.6.2
Impacts of electromagnetic fields on flora and fauna (plants, agricultural crops, honeybees, wildlife, livestock) 4.5.6.3
Floodplains and wetland on power line right-of-way 4.5.7

Air Quality

Air quality effects of transmission lines

4.5.2

Land Use

Onsite land use

4.5.3

Power line right-of-way

4.5.3

A brief description of the staff's review and GEIS conclusions, as codified in Table B-1, for each of these issues follows:

  • Power line right-of-way management (cutting and herbicide application): Based on information in the GEIS, the Commission found that "The impacts of right-of-way maintenance on wildlife are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, consultation with the FWS and SCDNR, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of power line right-of-way management during the renewal term beyond those discussed in the GEIS.
  • Bird collisions with power lines: Based on information in the GEIS, the Commission found that "Impacts [of bird collisions with power lines] are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information, including the status of the Duke monitoring program, Duke efforts to document collisions, and Duke efforts to protect species nesting on the power lines. Therefore, the staff concludes that there are no impacts of bird collisions with power lines during the renewal term beyond those discussed in the GEIS.
  • Impacts of electromagnetic fields on flora and fauna (plants, agricultural crops, honeybees, wildlife, livestock): Based on information in the GEIS, the Commission found that "No significant impacts of electromagnetic fields on terrestrial flora and fauna have been identified. Such effects are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of electromagnetic fields on flora and fauna during the renewal term beyond those discussed in the GEIS.
  • Floodplains and wetland on power line right-of-way: Based on information in the GEIS, the Commission found that "Periodic vegetation control is necessary in forested wetlands underneath power lines and can be achieved with minimal damage to the wetland. No significant impact is expected at any nuclear power plant during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, consultation with the FWS, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on floodplains and wetland on the power line right-of-way during the renewal term beyond those discussed in the GEIS.
  • Air quality effects of transmission lines: Based on information in the GEIS, the Commission found that "Production of ozone and oxides of nitrogen is insignificant and does not contribute measurably to ambient levels of these gases." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no air quality impacts of transmission lines during the renewal term beyond those discussed in the GEIS.
  • Onsite land use: Based on information in the GEIS, the Commission found that "Projected onsite land use changes required during ... the renewal period would be a small fraction of any nuclear power plant site and would involve land that is controlled by the applicant." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no onsite land-use impacts during the renewal term beyond those discussed in the GEIS.
  • Power line right-of-way (land use): Based on information in the GEIS, the Commission found that "Ongoing use of power line rights-of-way would continue with no change in restrictions. The effects of these restrictions are of small significance." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of restriction on use of power line rights-of-way during the renewal term beyond those discussed in the GEIS.

There is one Category 2 issue related to transmission lines, and another issue related to transmission lines is being treated as a Category 2 issue. These issues are listed in Table 4-5. They are discussed in Sections 4.2.1 and 4.2.2.

Table 4-5. Category 2 Issues Applicable to the ONS Transmission Lines During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Section 10 CFR 51.53(c)(3)(ii) Subparagraph SEIS Section

Human Health

Electromagnetic fields, acute effects (electric shock) 4.5.4.1 H 4.2.1
Electromagnetic fields, chronic effects 4.5.4.2 NA 4.2.2

4.2.1 Electromagnetic Fields - Acute Effects

In the GEIS, the Commission found that without a review of the conformance of each nuclear plant transmission line with NESC criteria, it is not possible to determine the significance of the electric shock potential. Evaluation of individual plant transmission lines is necessary because the issue of electric shock safety was not addressed in the licensing process for some plants. For the other plants, some may have chosen to upgrade line voltage or land use in the vicinity of transmission lines that may have been changed. To comply with 10 CFR 51.53(c)(3)(ii)(H), the applicant must provide an assessment of the potential shock hazard if the transmission lines that were constructed for the specific purpose of connecting the plant to the transmission system do not meet the recommendations of the National Electric Safety Code (NESC) for preventing electric shock from induced currents.

In the ER, Duke stated that the transmission lines that connect Units 1 and 2 to the 230 kV switching station and the lines that connect Unit 3 to the 525 kV switching station meet the vertical clearance requirement specified in the 1997 edition of NESC (1997). Duke states further that the transmission lines constructed concurrently with the Oconee and the Keowee-Toxaway Project are part of the Duke Energy Transmission System. These transmission lines were constructed to the standards of NESC, 6th edition, published in November 1961. According to the ER, there have been no upgrades in line voltage on these transmission lines since they were constructed. Duke reviewed the vertical clearances of the 528 km (330 mi) of transmission lines attributed to Oconee in the FES (AEC 1972) using the 1997 edition of NESC and determined that all clearances exceeded the minimum requirements of the 1997 NESC (Duke 1999a).

Based on the above, the staff concludes that the impact of the potential for electrical shock is SMALL, and mitigation is not warranted.

4.2.2 Electromagnetic Fields - Chronic Effects

In the GEIS, the chronic effects of electromagnetic fields from power lines were given a finding of "not applicable" rather than a Category 1 or 2 designation until a scientific consensus is reached on the health implications of these fields.

The potential for chronic effects from these fields continues to be studied and is not known at this time. The National Institute of Environmental Health Sciences (NIEHS) directs related research through the U.S. Department of Energy (DOE). A recent report (NIEHS 1999) includes the following paragraph:

The NIEHS concludes that ELF-EMF [extremely low frequency-electromagnetic field] exposure cannot be recognized as entirely safe because of weak scientific evidence that exposure may pose a leukemia hazard. In our opinion, this finding is insufficient to warrant aggressive regulatory concern. However, because virtually everyone in the United States uses electricity and therefore is routinely exposed to ELF-EMF, passive regulatory action is warranted such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures. The NIEHS does not believe that other cancers or non-cancer health outcomes provide sufficient evidence of a risk to currently warrant concern.

This statement is not sufficient to cause the staff to change its position with respect to the chronic effects of electromagnetic fields. The staff considers the GEIS finding of "not applicable" still appropriate and will continue to follow developments on this issue.

4.3 Radiological Impacts of Normal Operations

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS with regard to radiological impacts are listed in Table 4-6. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-6. Category 1 Issues Applicable to Radiological Impacts of Normal Operations During the Renewal Term

ISSUE--10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Section

Human Health

Radiation exposures to public (license renewal term) 4.6.2
Occupational radiation exposures (license renewal term) 4.6.3

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

  • Radiation exposures to public (license renewal term): Based on information in the GEIS, the Commission found that "Radiation doses to the public will continue at current levels associated with normal operations." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of radiation exposures to the public during the renewal term beyond those discussed in the GEIS.
  • Occupational radiation exposures (license renewal term): Based on information in the GEIS, the Commission found that "Projected maximum occupational doses during the license renewal term are within the range of doses experienced during normal operations and normal maintenance outages, and would be well below regulatory limits." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of occupational radiation exposures during the renewal term beyond those discussed in the GEIS.

4.4 Socioeconomic Impacts of Plant Operations During the License Renewal Period

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to socioeconomic impacts during the renewal term are listed in Table 4-7. Duke stated in its ER (Duke 1998a) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are small, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-7. Category 1 Issues Applicable to Socioeconomics During the Renewal Term

ISSUE--10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Sections

Socioeconomics

Public services: public safety, social services, and tourism and recreation 4.7.3; 4.7.3.3; 4.7.3.4; 4.7.3.6
Public services: education (license renewal term) 4.7.3.1
Aesthetic impacts (license renewal term) 4.7.6
Aesthetic impacts of transmission lines (license renewal term) 4.5.8

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

  • Public services: public safety, social services, and tourism and recreation: Based on information in the GEIS, the Commission found that "Impacts to public safety, social services, and tourism and recreation are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on public safety, social services, and tourism and recreation during the renewal term beyond those discussed in the GEIS.
  • Public services: education (license renewal term): Based on information in the GEIS, the Commission found that "Only impacts of small significance are expected." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on education during the renewal term beyond those discussed in the GEIS.
  • Aesthetic impacts (license renewal term): Based on information in the GEIS, the Commission found that "No significant impacts are expected during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no aesthetic impacts during the renewal term beyond those discussed in the GEIS.
  • Aesthetic impacts of transmission lines (license renewal term): Based on information in the GEIS, the Commission found that "No significant impacts are expected during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no aesthetic impacts of transmission lines during the renewal term beyond those discussed in the GEIS.

Table 4-8 lists the Category 2 socioeconomic issues, which require plant-specific analysis and environmental justice, which was not addressed in the GEIS.

4.4.1 Housing Impacts During Operations

In determining housing impacts, the applicant chose to follow Appendix C of the GEIS (NUREG-1437), which presents a population characterization method that is based on two factors, "sparseness" and "proximity" (GEIS Section C.1.4). Sparseness measures population density within 32 km (20 mi) of the site, and proximity measures population density and city size within 80.5 km (50 mi). Each factor has categories of density and size (GEIS Table C.1), and a matrix is used to rank the population category as low, medium, or high (GEIS, Figure C.1). ONS was selected by the NRC to be evaluated as a potential socioeconomic case study site. The results of this evaluation, published in the GEIS, classifies the current ONS population as "medium" (GEIS Table C.2).

Table 4-8. Category 2 Issues Applicable to Socioeconomics During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1 GEIS Section 10 CFR 51.53(c)(3)(ii) Subparagraph SEIS Section

Socioeconomics

Housing impacts 4.7.1 I 4.4.1
Public services: public utilities 4.7.3.5 I 4.4.2
Offsite land use (license renewal term) 4.7.4 I 4.4.3
Public Services, transportation 4.7.3.2 J 4.4.4
Historic and archaeological resources 4.7.7 K 4.4.5

Environmental Justice

Environmental Justice Not addressed   4.4.6

As described in Section 2.2.8, the Tri-County (Oconee, Pickens, and Anderson) area around ONS is not subject to growth control measures that effectively limit housing development, although Oconee County in particular is attempting to steer the growth toward the center of the county, where the infrastructure is most completely developed. In 10 CFR Part 51, Subpart A, Appendix B, Table B-1, NRC concluded that impacts on housing availability are expected to be of small significance at plants located in a "medium" population area where growth control measures are not in effect. ONS is located in a medium population area and is not located in an area where growth control measures limit housing development, so housing impacts would be expected to be small, even if there were plant-related increases in population.

Small impacts result when no discernable change in housing availability occurs, changes in rental rates and housing values are similar to those occurring statewide, and no housing construction or conversion occurs. Although significant housing impacts are expected in all three counties as a result of population growth, it will be difficult to discern the impact from license renewal activities. Although the GEIS assumed an additional staff of 180 permanent workers during the license renewal period, Duke, in the ER, indicated that they "have not identified any increases in staffing related to license renewal-related programs." The staff has reviewed the available information relative to housing impacts. Because Duke expects no increase in staffing levels, there should be no discernable change in housing availability. Therefore, there will be no impact on economic development from license renewal and the staff has concluded that the impact on housing during the license renewal period is SMALL, and mitigation is not warranted.

4.4.2 Public Services: Public Utility Impacts During Operations

Impacts on public utility services are considered small if there is little or no change in the ability of the system to respond to the level of demand, and thus there is no need to add capital facilities. Impacts are considered moderate if overtaxing of service capabilities occurs during periods of peak demand. Impacts are considered large if existing levels of service (e.g., water or sewer services) are substantially degraded, and additional capacity is needed to meet ongoing demands for services. The GEIS indicates that, absent new significant information to the contrary, the only impacts on public utilities that could be significant are impacts on public water supplies. The staff believes that, in view of the expected population increase in the three counties, there may be reason to add significant public services and infrastructure other than water supply during the next 40 years. None of the increase would be due to the impact of additional ONS workers because no need for additional workers has been identified.

Analysis of impacts to the public water supply system considered both plant demand and plant-related population growth. Section 2.2.2 describes the plant's permitted withdrawal rate and the plant's actual use of water. The applicant does not expect plant demand to have a direct effect on water resources.

As described in Section 2.2.8, Walhalla and Seneca in eastern Oconee County have some water plant capacity problems, but only Walhalla is actually limited by the water source (Coneross Creek). Walhalla is considering construction of a new water treatment plant. Seneca draws drinking water from Lake Keowee, which is considered adequate. Because ONS obtains its water from an adequate renewable surface water source, and no increase in population is expected as a result of the renewal of the ONS operating license, no impact is expected from license renewal on water supplies. The staff concludes that the impact on water supply is SMALL, and mitigation is not warranted.

4.4.3 Offsite Land Use During Operations

Land use in the vicinity of a nuclear power plant may change as a result of plant-related population growth. It is noted in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that significant changes in land use may be associated with population and tax revenue changes resulting from license renewal. However, Section 3.7.5 of the GEIS notes that if the plant-related increase in population is less than 5 percent of the study area's total population and if plant total tax payments are small relative to the community's total revenue, new population-driven and tax-driven land-use changes during the plant's license renewal term would be small, especially if the community has pre-established patterns of development and has provided adequate public services to support and guide development.

The analysis of offsite land use during the renewal term has two components, population-driven changes in offsite land use and tax-driven changes in offsite land use. No plant-related, population-driven changes in land use are expected during the license renewal term because no increase in employment is expected.

Oconee County is the only jurisdiction that taxes ONS directly, and it is the principal jurisdiction that receives direct tax revenue as a result of ONS's presence. Because there are no major refurbishment activities and no new construction as a result of the license renewal, no new sources of plant-related tax payments are expected that could significantly influence land use in Oconee County. However, continued operation of the plant would provide a significant continuing source of tax revenues to Oconee County. As discussed in Section 2.8, the applicant is expected to pay $22.3 million in property taxes to Oconee County in 1998-99. This payment represented about one-third of the county budget and has a substantial, positive impact on the fiscal condition of Oconee County.

The staff has determined that the significance of project-related tax payments are moderate if the payments to a jurisdiction are between 10 and 20 percent of the total tax revenue of the jurisdiction, and large if the percentage is greater than 20 percent (GEIS). Using these criteria, ONS tax payments, representing around 33 percent of the total Oconee County budget, are of large significance. If the tax-related revenues are medium to large relative to the jurisdiction's total revenue, tax-driven land-use changes would most likely be moderate if the community has no pre-established patterns of development (i.e., land-use plans or controls), or has not provided adequate public services to guide land-use changes in the past (GEIS). The staff defined the magnitude of land-use changes as follows:

  • SMALL - Very little new development and minimal changes to the area's land-use pattern.
  • MODERATE - Considerable new development and some changes to land-use patterns.
  • LARGE - Large-scale new development and many changes to land-use patterns.

Oconee County has experienced significant population growth and moderate land-use changes. The growth is not directly related to the presence of the ONS. Other factors, such as development of Lake Keowee recreational property, industrial growth, proximity to Greenville and Anderson, and less stringent land-use, zoning, and development regulations compared to surrounding counties clearly play a role. Oconee County has not adopted land codes or ordinances nor does it enforce a minimum housing code (Talbert & Bright 1996). However, Oconee County has well established patterns of development and has public services in place to support development, which is being directed toward the center of the county. In combination, these two factors would be expected to result in SMALL land-use impacts from ONS-related taxes.

Continuation of Oconee County's tax receipts from ONS keeps tax rates below what they otherwise would have to be to fund the county's government and also provides for a higher level of public infrastructure and services than otherwise would be possible. This enhances the county's attractiveness as a place to live and tends to accelerate the conversion of open space to residential and commercial uses. On the other hand, the presence of Duke's real estate arm as a major landowner has provided a considerable degree of discipline on development in the county.

Based on this review of the issues, the staff concludes that the net impact of plant-related population increases and tax receipts is likely to be SMALL. While the tax receipts are large enough to result in moderate impacts on land use, Oconee County has a conservative approach to providing water and sewer that limits upgrades and could slow future economic development except in areas already served. In addition, while the relatively low taxes and high levels of public service afforded by ONS-related tax receipts tend to draw population growth to the County, these same receipts make possible formal tax relief programs that favor open space or land-use control programs if such programs are deemed necessary in the future. Additional mitigation does not appear to be warranted.

4.4.4 Public Services: Transportation Impacts During Operations

On October 4, 1999, 10 CFR 51.53(c)(3)(ii)(J) and 10 CFR Part 51, Subpart A, Appendix B, Table B-1 were revised to clearly state that "Public Services: Transportation Impacts During Operations" is a Category 2 issue (see NRC 1999a for more discussion of this clarification). This issue is treated as such in this final SEIS.

Significant population growth is expected in all three counties in the study area by 2034, as was discussed in Section 2.2.8 of this report. However, none of this expected growth will be due directly to increases in employment at ONS. It may be argued that the industrial tax base afforded by ONS makes the county a more affordable and pleasant place to live and indirectly increases population, but even this indirect impact is likely to be fairly small and difficult to predict. Future general population increase likely will increase highway congestion at specific locations, but the expected magnitude of impact of ONS on this service degradation is SMALL and, thus, no mitigation is warranted.

4.4.5 Historical and Archaeological Resources

Because the Duke license renewal application (Duke 1998a) covering an additional 20 years of operation of the ONS does not include plans for future land disturbances or structural modifications beyond routine maintenance activities at the plant, there would be no identifiable adverse effects to known historical and archaeological resources. Consultation between the license renewal applicant and the South Carolina State Historic Preservation Office resulted in a determination by the State office that no known historical properties included in or eligible for inclusion in the National Register of Historic Places would be affected by the proposed action.

Continued operation of the power plant and protection of the natural landscape and vegetation within the site boundaries would have a beneficial effect in that either known or undiscovered resources would receive de facto protection for the term of the license renewal period, being located in an undisturbed area with secured access. Duke has assisted in conservation and security of the adjacent National Register property, the Old Pickens Church and cemetery. This assistance will continue to enhance long-term preservation of that property.

Notwithstanding that Duke does not plan future land disturbances or structural modifications beyond routine maintenance at the plant, there is a possibility that undiscovered and/or unrecorded prehistoric and historic period archaeological sites remain on the 210-ha (510-acre) plant site. Accordingly, additional care should be taken during normal operational or maintenance conditions to ensure that cultural resources are not inadvertently impacted. These activities may include not only operation of the plant itself, but also land management-related actions such as recreation, wildlife habitat enhancement, or maintaining/upgrading access roads throughout the plant site. To ensure that care is taken to protect cultural resources that may be encountered during construction or other land-disturbing activities, the ONS site environmental work practices have been revised. If archeological sites are identified during land-disturbing activities, land-disturbing activities will stop, and the State Historic Preservation Office will be contacted to determine the appropriate steps to be taken before resuming the activities.

The staff concludes that impacts on historical and archaeological resources is SMALL, and mitigation is not needed.

4.4.6 Environmental Justice

Environmental justice refers to a Federal policy in which Federal actions should not result in disproportionately high and adverse impacts on low-income or minority populations. A minority population is defined to exist if the percentage of minorities within the census blocks exceeds the percentage of minorities in the entire state of South Carolina by 10 percent, or if the percentage of minorities within the census block is at least 50 percent. For census blocks within the states of Georgia or North Carolina, the percentage of minorities is compared to the percentage of minorities in the respective state. Executive Order 12898 (59 FR 7629) directs Federal executive agencies to consider environmental justice under NEPA, and the Council on Environmental Quality (CEQ) has provided guidance for addressing environmental justice under NEPA (CEQ 1997). Although it is not subject to the executive order, the Commission has voluntarily committed to undertake environmental justice reviews. Specific guidance is provided in Attachment 4 to NRR (Nuclear Reactor Regulation) Office Letter No. 906, Revision 1: Procedural Guidance for Preparing Environmental Assessments and Considering Environmental Issues (NRC 1996b).

The scope of the review as defined in NRR Office Letter No. 906, Rev. 1 (NRC 1996b) should include an analysis of impacts on low-income and minority populations, the location and significance of any environmental impacts during operations on populations that are particularly sensitive, and any additional information pertaining to mitigation. The descriptions to be provided by this review should be of sufficient detail to permit subsequent staff assessment and evaluation of specific impacts, in particular whether these impacts are likely to be disproportionately high and adverse, and to evaluate the significance of such impacts.

Air, land, and water resources within about 80 km (50 mi) of ONS were examined. Within that area, a few potential environmental impacts could affect human populations; all of these were considered small. These include

  • groundwater use conflicts
  • electric shock
  • microbial organisms
  • accident scenarios.

To decide whether any of these impacts could be disproportionate, the staff examined the geographic distribution of minority and low-income populations recorded during the 1990 Census (DOC 1991), supplemented by field inquiries to the local planning departments in Oconee, Pickens, and Anderson Counties, and to social service agencies in the three counties. The staff focused this portion of the review on the geographic areas most likely to experience the impacts discussed above, i.e., the three closest surrounding counties. This area is referred to as the study area.

Generally speaking, minority populations are a small, dispersed, and declining proportion of the study area's population. Figure 4-1, taken from the 1990 Census (DOC 1991) shows the geographic distribution of minority populations within the 80-km (50-mi) radius of the plant. Minority populations are located primarily in Greenville and Anderson. However, a few scattered census block groups showed a significant concentration of minority individuals in the Seneca and Clemson areas. Figure 4-1 indicates that minority populations in general are either relatively well-mixed into the majority population, or concentrations of minority individuals are too small to be caught in the census detail. This is consistent with the results of field interviews.

Figure 4-2, also taken from the 1990 Census (DOC 1991) shows the geographic distribution of low-income populations within the 80-km (50-mi) radius of the plant. The cross-hatched census blocks show areas where the percentage of households below the poverty level is 10 percent or more greater than the percentage of households below the poverty level in the entire state of South Carolina for those census blocks within the state of South Carolina. It also includes census blocks where the percentage of households below the poverty level exceeds 50 percent. For census blocks within the states of Georgia or North Carolina, the percentage of households below the poverty level is compared to the percentage of households below the poverty level in the corresponding state. The largest concentrations of low-income populations within the 80-km (50-mi) radius are located in North Carolina. Some small groups are scattered throughout the three-county area, although none is within 16 km (10 mi) of ONS. Some of these individuals are known to be ex-sharecroppers effectively engaged in subsistence agriculture. The 1990 Census (DOC 1991) shows concentrations of low-income population at Seneca, Easley, and Clemson, the latter partly due to a large university student population. Low-income housing tends to be concentrated in the Seneca and Clemson area.

Figure 4-1. Geographic Distribution of Minority Populations (shown in shaded areas) Within 80 km (50 mi) of ONS

Examination of the various environmental pathways by which low-income and minority populations could be disproportionately affected reveals no unusual resource dependencies or practices through which these populations could be disproportionately affected. Specifically, no pathways were found through which subsistence agriculture was significantly affected. In general, the prevailing atmospheric transport direction from the ONS site is toward the northeast, thus missing most census blocks showing minority and low-income populations. Therefore, the impact is SMALL, and no special mitigation actions are warranted.

Figure 4-2. Geographic Distribution of Low-Income Populations (shown in shaded areas) Within 80 km (50 mi) of ONS

4.5 Groundwater Use and Quality

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A Category 1 issue in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, is applicable to ONS groundwater use and quality and is listed in Table 4-9. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review.

Table 4-9. Category 1 Issue Applicable to Groundwater Use and Quality During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1

GEIS Section

Groundwater Use and Quality

Groundwater use conflicts (potable and service water; plants that use <100 gpm). 4.8.1.1

Therefore, the staff concludes that there are no impacts related to this issue beyond those discussed in the GEIS. For this issue, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, follows.

  • Groundwater use conflicts (potable and service water; plants that use <100 gpm): Based on information in the GEIS, the Commission found that "Plants using less than 100 gpm are not expected to cause any groundwater use conflicts." As discussed in Section 2.2.2, ONS's groundwater use is less than 0.068 m3/s (100 gpm). The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no groundwater use conflicts during the renewal term beyond those discussed in the GEIS.

There are no Category 2 issues related to groundwater use and quality.

4.6 Threatened or Endangered Species

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Threatened or endangered species is listed as a Category 2 issue in 10 CFR Part 51, Subpart A, Appendix B, Table B-1. The issue is listed in Table 4-10.

This issue requires consultation with appropriate agencies to determine whether threatened or endangered species are present and whether they would be adversely affected. Consultation under Section 7 of the Endangered Species Act was initiated by Duke during April 1998 with a request for information to FWS concerning species potentially occurring near ONS. The FWS identified (FWS 1998a) nine listed species known to occur in either Oconee or Pickens Counties and one species that could possibly occur in those counties (see Section 2.2.6). Subsequent to that letter, Duke performed a survey of all of the land within 1.6 km (1 mi) of ONS during May and June of 1998. No Federally listed, proposed, or candidate threatened or endangered species were identified during that survey. The results of the survey were documented for the FWS and the South Carolina Department of Natural Resources (SCDNR) (Duke 1998b; Duke 1998c).

Table 4-10. Category 2 Issue Applicable to Threatened or Endangered Species During the Renewal Term

ISSUE -- 10 CFR Part 51, Subpart A, Appendix B, Table B-1

GEIS Section 10 CFR 51.53(c)(3)(ii) Subparagraph SEIS Section

Threatened or Endangered Species (for all plants)

Threatened or endangered species

4.1

E 4.6

The FWS concurred with Duke's determination that the proposed action will have no effect on listed or proposed endangered or threatened species (FWS 1998b). The SCDNR also concurred with the findings presented in the report submitted by Duke (SCDNR 1998).

Four plant species of concern to the SCDNR were identified within the surveyed area (see Section 2.2.6, Table 2-3). These species were all confined to "natural areas" located toward the periphery of ONS, well away from areas used for normal plant operations.

Based on its review of the applicant's report and their independent analysis, the FWS(1) and the SCDNR concluded that continued operation of the plant under license renewal will have no effect on listed or proposed endangered or threatened species within the immediate vicinity of the ONS.

Federally-listed species are known to occur near the transmission line rights-of-way attributable to the ONS (see Section 2.2.6). Of these, the dwarf-flowered heartleaf and the bunched arrowhead occur within or very near the rights-of-way of the McGuire 525 kV line and the Tiger 230 kV lines, respectively.

The staff submitted a biological assessment to the FWS in a letter dated June 30, 1999 (NRC 1999b). The FWS reviewed the biological assessment and requested more information related to Duke's maintenance practices for the transmission lines and the location of five species: bunched arrowhead, dwarf-flowered heartleaf, smooth coneflower, Schwenitz's sunflower, and mountain sweet pitcher plant. The FWS was concerned about the potential effects from the proposed maintenance of the right-of-way. The FWS conducted field visits to portions of the project area and reviewed the supplemental information provided by Duke. Subsequently, in a letter dated November 4, 1999 (FWS 1999), the FWS concurred with the staff's determination that the renewal of the ONS licenses for a period of 20 years would likely not adversely affect listed species or critical habitat based on the practices and procedures Duke uses to maintain the transmission line rights-of-way. Therefore, it is the staff's determination that the impact on threatened or endangered species of an additional 20 years of maintenance activities for the transmission lines would be SMALL, and further mitigation is not warranted.

4.7 Evaluation of Potential New and Significant Information on Impacts of Operations During the Renewal Term

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The staff has not identified new and significant information on environmental issues listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, related to operation during the renewal term. The staff reviewed the discussion of environmental impacts associated with operation during the renewal term in the GEIS and has conducted its own independent review, including the public scoping meetings, to identify issues with significant new information. Processes for identification and evaluation of new information are described in Section 1.0 under License Renewal Evaluation Process.

4.8 Summary of Impacts of Operations During the Renewal Term

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Neither Duke nor the staff is aware of significant new information related to any of the applicable Category 1 issues associated with the ONS operation during the renewal term. Consequently, the staff concludes that the environmental impacts associated with these issues are bounded by the impacts described in the GEIS. For each of these issues, the GEIS concluded that the impacts would be SMALL and that "plant-specific mitigation measures are not likely to be sufficiently beneficial to warrant implementation."

Plant-specific environmental evaluations were conducted for 12 Category 2 issues applicable to ONS operation during the renewal term and for environmental justice. For all 12 issues and environmental justice, the staff concluded that the potential environmental impact of renewal term operations of ONS would be of SMALL significance in the context of the standards set forth in the GEIS and that mitigation would not be warranted.

In addition, the staff determined that a consensus has not been reached by appropriate Federal health agencies that there are adverse effects from electromagnetic fields. Therefore, no evaluation of this issue is required.

4.9 References

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10 CFR 50.51, "Continuation of license."

10 CFR 51.53, "Postconstruction environmental reports."

10 CFR Part 51, Subpart A, Appendix B, "Environmental effect of renewing the operating license of a nuclear power plant."

Barwick, D.H. 1984. Role of fish distribution on estimates of standing crop in a cooling reservoir. North American Journal of Fishery Management 4:308-313.

Barwick, H. 1990. Fish impingement at Oconee Nuclear Station - 1990. Scientific Services, Duke Power Company, Huntersville, North Carolina.

Barwick, D.H., L.E. Miller, W.R. Geddings, and D.M. Rankin. 1995. Fish biomass and angler harvest from a South Carolina cooling reservoir. Proceedings of the Annual Conference of the Southeastern Association of Fish and Wildlife Agencies 49:129-139.

Council on Environmental Quality (CEQ). 1997. Environmental Justice: Guidance Under the National Environmental Policy Act. Council on Environmental Quality, Executive Office of the President, Washington, D.C.

Duke Power Company. 1977. Oconee Nuclear Station Environmental Summary Report 1971-1976, Volumes 1 and 2. Duke Power Company Steam Production Department.

Duke Power Company. 1995. Oconee Nuclear Station 316(a) Demonstration Report.

Duke Energy Corporation. 1998a. Application for Renewed Operating Licenses, Oconee Nuclear Station, Units 1, 2, & 3. Volume IV - Environmental Report.

Duke Power Company. 1998b. Letter from J. Huff, Duke Power, Charlotte, North Carolina, to Mr. R. L. Banks (FWS, Charleston, South Carolina) June 23, 1998, Conveys the Gaddy Report to FWS.

Duke Power Company. 1998c. Letter from J. Huff, Duke Power, Charlotte, North Carolina to R.E. Duncan, SCDNR. Dated June 23, 1998. Conveys the Gaddy Report to SCDNR.

Duke Energy Corporation. 1999a. Letter from M.S. Tuckman, Duke Energy Corporation to US Nuclear Regulatory Commission. Subject: License Renewal. Response to Requests for Additional Information, Oconee Nuclear Station. Dated March 4, 1999.

Duke Energy Corporation. 1999b. Letter from M.S. Tuckman, Duke Energy Corporation to U.S. Nuclear Regulatory Commission. Subject: Followup to Staff's Request for Additional Information. Dated December 29, 1998, Related to the Environmental Position of the Review of the License Renewal Application for Oconee Units 1, 2, and 3. Dated May 13, 1999.

Edwards, T.J., W.H. Hunt, L.E. Miller, and J.J. Sevic. 1976. "An evaluation of the impingement of fishes at four Duke Power Company steam-generating facilities." Pages 373-380 in Esch, G.W. and R.W. McFarlane (eds.). Thermal Ecology II. National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia.

Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority and Low-Income Populations." 59 Federal Register 7629-7633 (1994).

Federal Water Pollution Control Act (FWPCA), as amended, 33 USC 1251-1387 (also known as Clean Water Act).

Griffith, J.S. 1978. Effects of low temperature on the survival and behavior of threadfin shad, Dorosoma petenense. Transactions of the American Fisheries Society. 107:63-70.

Hudson and Nichols. 1978. Relation between zooplankton migration and entrainment in a South Carolina cooling reservoir. Waste Heat Management and Utilization Conference, Miami Beach, Florida, December 4-6, 1978.

National Electrical Safety Code (NESC). 1997. Institute of Electrical and Electric Engineers, Inc., New York.

National Institute of Environmental Health Sciences (NIESH). 1999. NIESH Report on Health Effects from Exposure to Power Line Frequency and Electric and Magnetic Fields. NIH Publication No. 99-4493. National Institutes of Health, Research Triangle Park, North Carolina.

Oliver and Hudson. 1987. Thermal and dissolved oxygen characteristics of a South Carolina cooling reservoir. Water Resources Bulletin, American Water Resources Association, 23(2):257-269.

Olmsted, L.L. and W.D. Adair. 1981. Protection of fish larvae at two southeastern power plants using skimmer walls. Research Report PES/81-30. Duke Power Company, Huntersville, North Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1997. Watershed Water Quality Assessment, Savannah and Salkehatchie River Basins. Technical Report No. 003-97, SCDHEC, Columbia, South Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1999. Letter from R. Michael, Gandy, South Carolina. Department of Health and Environmental Control to U.S. Nuclear Regulatory Commission. Subject: status of NPDES and land disposal permits for Oconee Nuclear Station. Dated April 21, 1999.

South Carolina Department of Natural Resources (SCDNR). 1998. Letter from Robert E. Duncan (SCDNR) to Ms. Jennifer Huff (Duke Power). September 24, 1998.

Talbert, S. J. & Bright, Inc., and Holland Consulting Planners, Inc. 1996. Oconee County, South Carolina 1996 Land Use Plan.

U.S. Atomic Energy Commission (AEC). 1972. Final Environmental Statement Related to Operation of Oconee Nuclear Station units 1, 2, and 3. March 1972. Washington, D.C.

U.S. Department of Commerce (DOC). 1991. 1990 Census-Population and Housing; Public Law 94-171 Data, Bureau of the Census. Washington, D.C.

U.S. Fish and Wildlife Service. 1998a. Letter from R. L. Banks (FWS, Charleston, South Carolina) to J. Huff (Duke Power, Charlotte, North Carolina) dated April 17, 1998. Letter provides a list of 9 species in Oconee and Pickens Counties.

U.S. Fish and Wildlife Service. 1998b. Letter dated August 4, 1998 from the Acting Field Supervisor for the Charleston Field Office to Duke Power indicating that continued operation or refurbishment of the Oconee Nuclear Station will have no effect on listed or proposed endangered or threatened species.

U.S. Fish and Wildlife Service. 1999. Letter dated November 4, 1999, from Brian P. Cole to U.S. Nuclear Regulatory Commission. Subject: Biological Assessment for License Renewal at Oconee Nuclear Station.

U.S. Nuclear Regulatory Commission (NRC). 1996a. Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1996b. Procedural Guidance for Preparing Environmental Assessments and Considering Environmental Issues, Attachment 4 to NRR Office Letter No. 906, Revision 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999a. Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Main Report, Section 6.3--Transportation, Table 9.1, Summary of Findings in NEPA issues for license renewal of nuclear power plants. NUREG-1437, Volume 1, Addendum 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999b. Letter from NRC to the U.S. Fish and Wildlife Service. Subject: Biological Assessment. Dated June 30, 1999, Washington, D.C.

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1. U.S. Fish and Wildlife Service. 1998. Letter dated August 4, 1998, from the Acting Field Supervisor for the Charleston Field Office to Duke Power indicating that continued operation or refurbishment of ONS will have no effect on listed or proposed endangered or threatened species.

Page Last Reviewed/Updated Thursday, March 29, 2012