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 13)

8.0 Environmental Impacts of Alternatives to License Renewal



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Section Contents

This chapter examines the potential environmental impacts associated with denying a renewed operating license (i.e., the no-action alternative); the potential environmental impacts from electric generating sources other than renewal of the ONS operating licenses; the potential impacts from instituting additional conservation measures to reduce the total demand for power; and the potential impacts from power imports. The impacts are evaluated using a three-level standard of significance--SMALL, MODERATE, or LARGE--based on Council on Environmental Quality (CEQ) guidelines. These significance levels are as follows:

   SMALL: Environmental effects are not detectable or are so minor that they will neither destabilize nor noticeably alter any important attribute of the resource.
MODERATE: Environmental effects are sufficient to alter noticeably, but not to destabilize important attributes of the resource.
LARGE: Environmental effects are clearly noticeable and are sufficient to destabilize important attributes of the resource.

8.1 No-Action Alternative

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For license renewal, the no-action alternative refers to a scenario in which NRC would not renew the ONS operating licenses, and the applicant would then decommission ONS when plant operations cease. Replacement of ONS electricity generation capacity would be met either by demand-side management and energy conservation (perhaps supplied by an energy service company), imported power, some generating alternative other than ONS, or some combination of these. However, due to the influence of the ongoing deregulation of the retail market, Duke might not be the ultimate power supplier.

Duke will be required to comply with NRC decommissioning requirements whether or not the operating licenses are renewed. If the ONS operating licenses are renewed, decommissioning activities may be postponed for up to an additional 20 years. If the licenses are not renewed, then Duke would begin decommissioning activities when plant operations cease, beginning in 2013 or perhaps sooner. The impacts of decommissioning would occur concurrently with the impacts of supplying replacement power. The GEIS (NRC 1996) and the Final Generic Impact Statement on Decommissioning of Nuclear Facilities, NUREG-0586 (NRC 1988) provide a description of decommissioning activities.

The environmental impacts associated with decommissioning under the no-action alternative would be bounded by the discussion of impacts in Chapter 7 of the GEIS, Chapter 7 of the SEIS, and NUREG-0586 (NRC 1988). The impacts of decommissioning after 60 years of operation generally would not be significantly different from those occurring after 40 years of operation.

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Socioeconomic: When ONS ceases operation, there will be a decrease in employment and tax revenues associated with the closure. This impact would be concentrated in Oconee County and to a lesser degree in Pickens, Anderson, and Greenville counties. Most secondary employment impacts and impacts on population would also be expected in these counties. Table 2.5 shows the current geographic distribution of the residences of ONS employees by county. Most of the tax revenue losses would occur in Oconee County. The no-action alternative results in the loss of these taxes and payrolls 20 years earlier than if the licenses are renewed (Table 8-1). Duke pays taxes on ONS of about $22 million per year to Oconee County, as stated in Section 2.2.8. This tax base would be lost in the no-action alternative. It is expected that energy costs in the area would also be higher in a regulated utility environment. It is not clear from the staff's interviews with local real estate agents and appraisers whether there would be a significant adverse impact on housing values as a result of closing ONS. While the loss of payrolls and workers would be substantial, particularly in Oconee County, future real estate values may be driven more by vacation/retirement home demand and the suburban growth surrounding Greenville.

Table 8-1. Summary of Environmental Impacts from No-Action Alternative

Impact Category Impact Comment
Socioeconomic MODERATE to LARGE Decrease in employment and tax revenues
Archaeological and Historical Resources SMALL to LARGE Sale or transfer of land within plant site leads to changes in land-use pattern
Environmental Justice SMALL to MODERATE Loss of employment opportunities and social programs
It is not clear that Duke's industrial recruitment efforts in the Tri-County region or their success would be maintained after closure of the Oconee plant. Duke's power costs would be expected to be higher without the plant, and there would be fewer incentives for Duke to assist in recruiting outside businesses into the region if its presence is significantly diminished.
The recreational property, lake, and hydroelectric facilities associated with the Keowee-Toxaway project are not likely to be affected by the closure of Oconee. However, there is one potential change that could be significant. In part, because of the need for clean water at the ONS, Duke has provided aggressive corporate, political, and technical leadership in maintaining high water quality in Jocasee and Keowee Lakes. Hydroelectric facilities can tolerate much lower water quality and Crescent Resources (the real estate division of Duke Energy Corporation) may have divested enough holdings by 2013 that Duke will have fewer corporate incentives to keep water quality exceptionally high if ONS closes. Therefore, the corporate and technical leadership and assistance that Duke voluntarily provides in the area of water quality monitoring may be less readily available.
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Archaeological and Historical Resources: The potential for future adverse impacts to known or unrecorded cultural resources at the ONS following decommissioning will depend on the future land use of the site. Known resources and activities include the current visitors' center and associated interpretative efforts that are funded and maintained by Duke. Eventual sale or transfer of the land within the plant site could result in adverse impacts to these resources should the land-use pattern change dramatically.
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Environmental Justice for No-Action: Current operations at ONS do not have disproportionate impacts on low-income and minority populations of the surrounding counties, and no environmental pathways have been identified that would cause disproportionate impacts. Since closure would result in a decrease in employment and tax revenues in Oconee County, it is possible that the county's ability to maintain social services could be reduced at the same time as diminished economic conditions reduce employment prospects for the low-income or minority populations. There is some possibility of negative and disproportionate impacts on low-income or minority populations from this source under the no-action alternative.

8.2 Alternative Energy Sources

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Nuclear power plants are commonly used for base-load generation; the GEIS indicates that coal-fired and gas-fired generation capacity are the feasible alternatives to nuclear power generating capacity, based on current (and expected) technological and cost factors. The alternatives of coal-fired generation and gas-fired generation are presented (Sections 8.2.1 and 8.2.2, respectively) as if such plants were constructed at the ONS site, using the existing water intake and discharge structures, switchyard, and transmission lines, or at an alternate location that could be either a current industrial site or an undisturbed, pristine site requiring a new generating building and facilities, new switchyard, and at least some new transmission lines. For purposes of this SEIS, a "greenfield" site is assumed to be an undisturbed, pristine site.

Depending on the location of an alternative site, it might also be necessary to provide a connection to the nearest gas pipeline (in the case of natural gas) or rail connection (in the case of coal). The requirement for these additional facilities also likely would increase the environmental impacts relative to those that would be experienced at the ONS site, although this is less certain.

The cooling water needs of a fossil-fired plant of equal capacity to the ONS facility would require the use of either a once-through cooling system located on a large body of water such as Lake Keowee or a closed cycle system using cooling towers.

The potential for using imported power is discussed in Section 8.2.3. Imported power is considered feasible, but would result in the transfer of environmental impacts from the current region in South Carolina to some other location in South Carolina, another state, or a Canadian province. Several other technologies were considered, but were determined not to be reasonable replacements for a nuclear power plant. These options included wind, solar, hydropower, geothermal, wood energy, municipal solid waste, oil, advanced nuclear, fuel cells, delayed retirement of other generating units, and utility-sponsored conservation as discussed in Section 8.2.4.

Some of the alternatives in this section are not inherently infeasible, but could not provide enough power on their own to replace the power from ONS. The final subsection considers the environmental consequences of a mix of alternatives. These impacts are the same or larger than the environmental consequences of relicensing.

8.2.1 Coal-Fired Generation

It was assumed that it would take 2500 MW(e) of coal-fired generation capacity to replace the approximately 2500-MW(e) ONS. The typical size [MW(e)] and configuration used by the electrical power industry in the application of coal-fired generation technology varies.

8.2.1.1 Once-Through Cooling System

Section 8.2.1.1 sets forth the environmental impacts of converting the current ONS site to a coal-fired generation facility with once-through cooling and building a similar facility on a greenfield site. Differences in impacts with closed-cycle cooling are covered in Section 8.2.1.2. Land use in the discussion that follows was based on two of Duke's current coal-fired generating plants: the four-unit, 2090-MW(e) Marshall Steam Station in Catawba County, North Carolina, which occupies 650 ha (1600 acres), and the 2-unit, 2370-MW(e) Belews Creek Steam Station in Stokes County, North Carolina, which occupies 280 ha (700 acres) (Duke 1999a). Environmental impacts were based on data in EPA (1995). The impacts are summarized in Table 8-2.

Construction of the coal-fired alternative would take approximately 5 years. The workforce during the construction period would be expected to average 1500, with a peak of 2500 (GEIS, adjusted for the larger scale of the ONS replacement plant) and during operations to average 500 (Duke 1998).

Additional water would be needed for controlling wet-scrubber sulfur dioxide emissions and for boiler makeup.

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Land Use
Based on Duke's operating experience, approximately 900,000 MT (1,000,000 tons) of solid waste per year would be generated, including 630,000 MT (700,000 tons) of flyash and bottom ash, selective catalytic reduction (SCR) catalyst (used for nitrogen oxides control), and sulfur oxide scrubber sludge/waste. Approximately 90 percent of the 630,000 MT (700,000 tons) of this ash would be flyash, and the remaining 10 percent would be bottom ash, depending on the type of coal burned and the type of emission control equipment used. The SCR catalyst would generate approximately 230 m3 (8000 ft3) of spent catalyst material per year. This catalyst material would have high concentrations of metals that are removed from the fly ash. A new coal-fired facility would also require sulfur oxides scrubbers to be installed as emission control equipment. This would result in the generation of approximately 350,000 MT (387,000 tons) per year of scrubber sludge. Facilities would be constructed to control and treat leachate from ash and scrubber waste

Table 8-2. Summary of Environmental Impacts from Coal Alternative--Once-Through Cooling

  Oconee Site Alternative "Greenfield" Site
Impact Category Impact Comments Impact Comments
Land Use MODERATE Uses another 220 ha (550 acres) within or adjacent to ONS site, plus 25 ha (60 acres) for 13-16 km (8-10  mi) rail line MODERATE to LARGE 200 ha (500 acres) to 800 ha (2000 acres), including transmission lines
Ecology MODERATE Uses undeveloped areas in current ONS site plus other nearby land, plus rail corridor MODERATE to LARGE Impact will depend on ecology of site
Water Use and Quality        
- Surface Water SMALL Uses existing intake and discharge structures

Volume 1 m3/sec (16,000) gpm and temperature rise same as ONS

SMALL to MODERATE Impact will depend on volume and other characteristics of receiving water
- Groundwater SMALL Little groundwater is currently used at ONS. This practice likely would continue SMALL to LARGE Impact will depend on site characteristics and availability of groundwater
Air Quality MODERATE Sulfur oxides MODERATE Same impacts as Oconee site, although pollution control standards may vary
    -11,800 MT (13,000 tons)/yr    
    -allowances required    
    Nitrogen oxides    
    -11,800 MT (13,000 tons)/yr    
    -allowances required    
    Particulate    
    -1600 MT (1800 tons)/yr    
    Carbon monoxide    
    -1600 MT (1800 tons)/yr    
    Carbon dioxide    
    -16 million MT (18 million tons)/yr    
    VOC    
    -190 MT (210 tons)/yr    
    Trace amounts of mercury, arsenic, chromium, beryllium, selenium    
Waste MODERATE Total waste volume would be 900,000 MT (1,000,000 tons)/yr of ash and scrubber sludge MODERATE Same impacts as Oconee site; waste disposal constraints may vary
Human Health SMALL Impacts considered minor SMALL Same impact as Oconee site
Socioeconomics MODERATE 1500 to 2500 additional workers during 5-year construction period, followed by reduction from current 1700 workforce to 500 persons MODERATE TO LARGE Construction impacts would be relocated. Community near ONS would still experience reduction from 1700 persons to 0 persons
Aesthetics MODERATE to LARGE Visual impact of large industrial facility and stacks would be significant MODERATE to LARGE Alternate locations could reduce aesthetic impact if siting is in an industrial area
Archeological and Historical Resources SMALL Affects previously developed parts of current ONS site, nearby land, and 13-16 km (8-10-mi) rail corridor SMALL Alternate location would necessitate cultural resource studies
Environmental Justice MODERATE Impacts on low income and minority communities should be similar to those experienced by the population as a whole. Some impacts on housing are likely. SMALL to LARGE Impacts will vary depending on population distribution and make up
disposal areas and runoff from coal storage areas. These facilities are included in the land-use estimates. The existing switchyard and transmission system would be used. Duke assumed that between 220 ha (550 acres) and 800 ha (2000 acres) would be required based on the Marshall and Belews Creek Duke coal-fired power plants. It is assumed that coal-fired generation structures and facilities, including coal storage and waste disposal, would be located in one or more of the unused areas of the Oconee site and on adjacent Duke-owned land.
As described above, the coal-fired generation alternative would necessitate converting roughly an additional 220 ha (550 acres) of the Duke-owned land across Highway 130 or 183 from the ONS (the current site is only 207 ha [512 acres]) to industrial use (plant, coal storage, and ash and scrubber sludge disposal), expanding the altered area at the site from 200 ha (500) acres to over 400 ha (1000 acres). The land surrounding ONS is owned by one of Duke's subsidiaries and could most likely be made available.
In addition, a new rail line would have to be built between Newry and the ONS site (13 to 16 km [8 to 10 mi]) requiring approximately 25 ha (60 acres) to bring the coal to the site. The impact of coal-fired generation on land use is best characterized as MODERATE; its impact would be greater than the proposed action.
In contrast, land use for a coal-fired generation alternative using once-through cooling at an alternative greenfield site would require 4 ha (10 acres) for offices, roads, etc. This is in addition to up to 800 ha (2000 acres) for generating facilities and cooling structures, coal storage ash basin, and flyash disposal discussed previously. Additional land might be needed for transmission lines, depending on the location of the site relative to the nearest intertie connection. Depending on the transmission line routing, these alternatives could result in MODERATE or LARGE land-use impacts consistent with the GEIS characterization of land use at a greenfield site.
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Ecology
Locating an alternate energy source at the existing ONS site would noticeably alter ecological resources because of using additional undeveloped areas and modifying the existing intake and discharge system. The impact to the Lake Keowee ecology would be expected to remain unchanged because the once-through cooling system at ONS has not shown significant negative impact to the lake. The appropriate characterization of coal-fired generation ecological impacts of the ONS site would be MODERATE; its impact would be greater than the proposed action.
Constructing a coal-fired plant at a greenfield site, particularly one sited in a rural area with considerable natural habitat, would certainly alter the ecology and could impact any endangered or threatened species present at the site. These ecological impacts could be MODERATE to LARGE, consistent with the GEIS characterization of ecological impacts at a greenfield site.
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Water Use and Quality
Surface Water. The coal-fired generation alternative is assumed to use the existing ONS intake and discharge structures as part of a once-through cooling system. This alternative would minimize environmental impacts since minimal construction would be required to adapt the system to the coal-fired alternative. It is assumed that the coal-fired alternative cooling water volume (1 m3/sec [16,000 gpm]) and temperature rise would be approximately the same as for the current nuclear plant. This temperature rise would comply with the existing ONS National Pollutant Discharge Elimination System (NPDES) permit. The GEIS analysis determined that surface water quality, hydrology, and use impacts for license renewal would be SMALL. Because the coal-fired generation alternative is assumed to have the same discharge characteristics as ONS, surface water impacts are expected to remain SMALL; the impacts would be so minor that they would not noticeably alter any important attribute of the resource.
For alternative greenfield sites, the impact to the surface water would depend on the volume associated with the cooling system and characteristics of the receiving body of water. The impacts would be SMALL or MODERATE.
Groundwater. No variation would be expected in the amount of groundwater used, since groundwater wells only are used to supply water for drinking and the restroom facility at the station baseball field, as well as to supply irrigation water for site landscaping during the summer months (June through September). However, the leachate from ash and scrubber waste disposal areas and runoff from coal storage areas would have to be controlled to avoid groundwater and surface water contamination. For this reason, the appropriate characterization of coal-fired generation groundwater impacts would be SMALL; the impacts would be so minor that they would not noticeably alter any important attribute of the resource.
For alternative greenfield sites, the impact to the groundwater would depend on the site characteristics, including the amount of groundwater available. The impacts would range between SMALL and LARGE.
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Air Quality
Air quality impacts of coal-fired generation vary considerably from those of nuclear power due to emissions of sulfur oxides, nitrogen oxides, particulates, and carbon monoxide. Although the entire State of South Carolina and the nearby areas of North Carolina and Georgia are currently in attainment for meeting National Ambient Air Quality Standards, the Oconee site is within 80 km (50 mi) of two Prevention of Significant Deterioration Class I areas (Great Smoky Mountains National Park and Shining Rock Wilderness Area) that would be of concern for a major coal-fired plant. Also, future economic and population growth may make future compliance more difficult.
Sulfur oxides emissions. Using current control technology for sulfur oxides emissions, the total annual stack emissions would include approximately 11,800 MT (13,000 tons) of sulfur oxides, most of which would be sulfur dioxide. Additional reductions could become necessary. The acid rain provision of the Clean Air Act (CAA) (Sections 403 and 404) capped the nation's sulfur dioxide emissions from power plants. Under the Act, affected fossil-fired steam units are allocated a number of sulfur dioxide emission allowances. To achieve compliance, each utility must hold enough allowances to cover its sulfur dioxide emissions annually or be subject to certain penalties. If the utility's sulfur dioxide emissions are less than its annually allocated emission allowances, then the utility may bank the surplus allowances for use in future years. A sulfur dioxide allowances market has been established for the buying and selling of allowances. Duke has sulfur dioxide allowances for its existing coal-fired plants; however, Duke would have to purchase additional allowances to operate an additional coal-fired plant (Duke 1999b). Because of allowances, any major new combustion facility in South Carolina would not add sulfur dioxide impacts on a regional basis, though it might do so locally.
Nitrogen oxides emissions. Using currently available control technology, the total annual nitrogen oxides emission would be approximately 11,800 MT (13,000 tons). Section 407 of the CAA establishes an annual reduction program for the nitrogen oxides emissions program. The new EPA 8-hour ozone standard, the new EPA PM2.5 particulate standard, and Regional Haze rules create additional burdens on coal use. To cite one example, the South Carolina Department of Health and Environmental Control (SCDHEC) has identified several counties that may be impacted, including Anderson and Greenville Counties, as well as counties of concern, including Oconee and Anderson Counties (South Carolina Air Quality Annual Report Volume XVII, 1997 [SCDHEC 1998]). To implement a coal-fired alternative, Duke might be required to offset its corporate nitrogen oxides emissions through further reductions in nitrogen oxides emissions elsewhere by shutting other sources down or by back-fitting to reduce nitrogen oxides formation (e.g., installing over-fired air, low nitrogen oxides burners, flue gas re-circulation, and selective non-catalytic and catalytic reduction systems). Alternatively, offsets might be available for purchase on the open market. A major new combustion facility would not add to net regional emissions, although it might do so locally.
Particulate emissions. The total estimated annual stack emissions would include 1600 MT (1800 tons) of particulate matter having a diameter of 10 microns or less (PM10). In addition, coal handling equipment would introduce fugitive particulate emissions.
Carbon monoxide emissions. The total carbon monoxide emissions would be approximately 1600 MT (1800 tons) per year.
Carbon dioxide emissions. The total carbon dioxide emissions would be approximately 16 million MT (18 million tons) per year.
Mercury. Coal-fired boilers account for nearly a third of mercury emissions in the United States. Technologies available to control mercury emissions have varying degrees of success. In response to growing concerns with mercury, the CAA Amendments of 1990 have required the EPA to identify mercury emission sources, evaluate the contributions of power plants and municipal incinerators, identify control technologies, and evaluate the toxicological effects from the consumption of mercury-contaminated fish. It is likely that these studies will lead to additional restrictions concerning mercury emissions associated with coal-fired power plants, as well as other sources of mercury emissions. Recent studies by the Maryland Power Plant Research Program have indicated that although coal-fired power plants contribute to mercury emissions, the resulting concentrations are not high enough to adversely affect humans or other organisms (Maryland Department of Natural Resources 1999). Therefore, the probable effect of trace mercury emissions on human health would be SMALL.
The GEIS analysis did not quantify coal-fired emissions, but implied that air impacts would be substantial and mentioned global warming and acid rain as potential impacts. Adverse human health effects from coal combustion have led to important Federal legislation in recent years, and public health risks, such as cancer and emphysema, have been associated with the products of coal combustion. Federal legislation and large-scale concerns, such as acid rain and global warming, are indications of concerns about air resources. Sulfur oxide emission allowances, nitrogen oxide emission offsets, low nitrogen oxide burners, overfire air, selective catalytic reduction, fabric filters or electrostatic precipitators, and scrubbers may be required as mitigation measures. As such, the appropriate characterization of coal-fired generation air impacts would be MODERATE. The impacts would be clearly noticeable, but would not destabilize air quality.
Siting the coal-fired generation elsewhere would not significantly change air quality impacts, although it could result in installing more or less stringent pollution control equipment to meet applicable standards. Therefore, the impacts would be MODERATE.
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Waste
Coal combustion generates waste in the form of ash, and equipment for controlling air pollution generates additional ash and scrubber sludge. Based on Duke experience at two coal-fired plants, approximately 900,000 MT (1,000,000 tons) of this waste would be generated annually for 40 years and disposed of onsite, accounting for between 60 percent and 40 percent of land used at the site (120 out of 200 ha to 160 out of 800 ha [300 out of 500 acres to 400 out of 2000 acres]). While only half of these values are directly attributable to the alternative to a 20-year ONS license renewal, the total values are pertinent as a cumulative impact. This impact could extend well after the 40-year operation life because revegetation management and groundwater monitoring for leachate contaminant impacts could be a permanent requirement.
The GEIS analysis concluded that large amounts of fly ash and scrubber sludge would be produced and would require constant management. Disposal of this waste could noticeably affect land use and groundwater quality, but with appropriate management and monitoring, it would not destabilize any resources. After closure of the waste site and revegetation, the land would be available for other uses, and regulatory requirements would ensure groundwater protection. For these reasons, the appropriate characterization of impacts from waste generated from burning coal would be MODERATE; the impacts would be clearly noticeable, but would not destabilize any important resource.
Siting the facility on an alternate greenfield site would not alter waste generation, although other sites might have more constraints on disposal locations. Therefore, the impacts would be MODERATE.
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Human Health
Coal-fired power generation introduces worker risks from fuel and lime/limestone mining and worker and public risks from fuel and lime/limestone transportation and stack emissions inhalation. Stack impacts can be very widespread and health risks difficult to quantify. This alternative also introduces the risk of coal-pile fires and attendant inhalation risks.
The GEIS analysis noted that there could be human health impacts (cancer and emphysema) from inhalation of toxins and particulates, but did not identify the significance of this impact. Regulatory agencies, such as the EPA and SCDHEC, focus on air emissions and revise regulatory requirements or propose statutory changes, based on human health impacts. Such agencies also impose site-specific emission permit limits as needed to protect human health. Thus, human health impacts from inhaling toxins and particulates generated by burning coal would be SMALL.
Using the same logic, siting the facility at an alternate greenfield site would not alter the expected human health effects. Therefore, the impacts would be SMALL.
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Socioeconomics
Construction of the coal-fired alternative would take approximately 5 years. It is assumed that construction would take place concurrently while ONS continues operation and would be completed at the time ONS would cease operations. Thus, the workforce would be expected to average 1500 with a peak of 2500 additional workers during the 5-year construction period, based on estimates given in the GEIS (NRC 1996) and scaled for the large plant size. The surrounding communities would experience demands on housing and public services that could have large impacts. After construction, the communities would be impacted by the loss of jobs; construction workers would leave, the nuclear plant workforce (1700) would decline through a decommissioning period to a minimal maintenance size, and the coal-fired plant would introduce only 500 new jobs.
The GEIS analysis concluded that socioeconomic impacts at a rural site would be larger than at an urban site because more of the 1200 to 2500 peak construction workforce would need to move to the area to work. While the site is not rural within the meaning of the GEIS, the facility is roughly twice the size examined in the GEIS. Operational impacts could result in moderate socioeconomic benefits in the form of several hundred additional jobs, substantial tax revenues, and plant expenditures.
The size of the construction workforce for a coal-fired plant and plant-related spending during construction would be noticeable. However, due to the site's proximity to large labor pools in the Greenville and Spartanburg areas, significant numbers of construction workers would not be expected to move to the ONS area. Operational impacts would include an eventual loss of approximately 1200 jobs (1700 for three nuclear units down to 500 for the coal-fired plant), with a commensurate reduction in demand on socioeconomic resources and contribution to the regional economy. The area's rapid population growth and the replacement industrial tax base resulting from the coal-fired power plant would prevent any destabilization of socioeconomic resources. For these reasons, the appropriate characterization of socioeconomic impacts for a coal-fired plant would be MODERATE; the impacts would be clearly noticeable, but would not destabilize any important resource.
Construction at another site would relocate some socioeconomic impacts, but would not eliminate them. The community around ONS would still experience the impact of ONS operational job loss, and the communities around the new site would have to absorb the impacts of a large, temporary workforce and a moderate, permanent workforce. Therefore, the impacts are MODERATE to LARGE, based on the adverse effects on the employment and the tax base in Oconee County, which would be similar to those of the no-action alternative.
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Aesthetics
Plant structures (the stacks) would be visible over intervening trees for kilometers around, particularly along Lake Keowee. This view would contrast strongly with what is otherwise a natural-appearing vacation-home and rural area, with woods and farming areas. Coal-fired generation would also introduce additional mechanical sources of noise (e.g., induced-draft fans and coal-handling equipment) that may be audible offsite due to their proximity to Lake Keowee.
The GEIS concluded that aesthetic impacts from such a large construction effort in a rural area could be substantial. Industrial structures that would be located at the Oconee site would tower above area vegetation and create a noticeable visual impact for a large area. Aesthetics is a significant attribute of Lake Keowee, given the predominantly natural-appearing rural viewscape from the lake and shoreline. A coal-fired generating station would contrast strongly with the existing resource. The aesthetics impacts would be MODERATE to LARGE, noticeable but not destabilizing.
Alternative locations could reduce the aesthetic impact of coal-fired generation if siting were in an area that was already industrialized. In such a case, however, the introduction of such tall stacks and cooling towers would probably still have a MODERATE incremental impact. Other sites could show a LARGE impact.
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Archaeological and Historical Resources
The GEIS analysis concluded that impacts to cultural resources would be relatively SMALL unless important site-specific resources were affected. Under this alternative, cultural resource inventories would be required for any lands that have not been previously disturbed to the extent that no archaeological or historical resources might remain. Other lands that are purchased to support the facility would also require an inventory of field cultural resources, identification and recording of extant archaeological and historical resources, and possible mitigation of adverse effects from subsequent ground-disturbing actions related to physical expansion of the plant site. Therefore, the impacts would be SMALL.
Construction at another site would necessitate studies to identify, evaluate, and mitigate potential impacts of new plant construction on cultural resources. This would be required for all areas of potential disturbance at the proposed plant site and along associated corridors where new construction would occur (e.g., roads, transmission corridors, or other rights-of-way). Impacts can generally be managed and maintained as SMALL.
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Environmental Justice
No environmental pathways have been identified that would result in disproportionately high and adverse environmental impacts on low-income and minority populations if a replacement coal-fired plant were built at the ONS site. Some impacts on housing availability and prices during construction might occur, and this could disproportionately affect the low-income and minority populations. Impacts at other sites would depend upon the site chosen. These impacts would be MODERATE.
If the replacement plant were built in Oconee County, the county's tax base would be largely maintained, and some potential negative socioeconomic impacts on the low-income or minority populations would be avoided. If the plant were built elsewhere, environmental justice impacts would be SMALL to LARGE, depending on the plant location and nearby population distribution.

8.2.1.2 Closed-Cycle Cooling System

This section describes the differences in impacts of using a mechanical draft closed-cycle cooling system at a coal-fired power plant that would replace ONS. These differences would be roughly the same at both the Oconee site and other greenfield sites. Mechanical draft cooling towers are 15 m (50 ft) to 30 m (100 ft) tall. Based on Duke's experience with similar cooling towers at the Catawba Nuclear Station, cooling water consumption would be approximately 1.5 m3/s (24,000 gpm) (Duke 1999a) and land-use requirements would be 10 to 12 ha (25 to 30 acres). The closed-cycle cooling system would introduce cooling tower blowdown that would be much higher in dissolved solids in comparison to Lake Keowee. Cooling tower operation would require more electrical power than the once-through cooling system due to the modified pumping systems. The towers would discharge a plume of water vapor and a measurable amount of cooling tower drift.

The changes in environmental impacts from redesigning the site for cooling towers are listed in Table 8-3. The overall impacts are also discussed below.

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Land Use
A closed-cycle cooling system alternative would impact an additional 10 to 12 ha (25 to 30 acres) for cooling tower construction at either the greenfield site or the ONS site (Duke 1999). These alternatives would result in a minor to moderate change above those already considered for the once-through cooling alternative. The overall impact would be MODERATE at ONS, MODERATE to LARGE elsewhere.

Table 8-3. Summary of Environmental Impacts from Alternate Cooling System
(Cooling Towers with Closed-Cycle Cooling)

Impact Category Change in Impact from ONS Once-Through Cooling Comments
Land Use Minor to moderate change 10-12 additional ha (25-30 acres) required
Ecology Minor change Additional impact to terrestrial ecology from cooling tower drift

Reduced impact to aquatic ecology

Water Use and Quality    
Surface Water Minor change Blowdown has higher dissolved solids

Reduced flow/Less thermal load

Groundwater No change None
Air Quality No change None
Waste No change None
Human Health No change None
Socioeconomics No change None
Aesthetics Small change Addition of 30-m (100-ft) high cooling towers

Noise from mechanical draft towers and vapor plume

Archaeology and Historical Resources Minor change Minimal cultural studies possibly required
Environmental Justice No change None
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Ecology
The closed-cycle cooling system alternative would further reduce operational aquatic ecology impacts, but would introduce risk to vegetation from salt drift. However, these ecological impacts result in minor changes above those for the once-through cooling alternative, resulting in MODERATE overall impacts at ONS and MODERATE to LARGE impacts elsewhere.
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Water Use and Quality
Surface Water. Although surface water impacts are expected to remain small, the closed-cycle cooling system alternative would introduce cooling tower blowdown that would have higher dissolved solids. However, because of the reduced flow, changes that impact surface water quality would result in minor changes above those already considered for the once-through cooling alternative. Thermal load would be less than with a once-through cooling system. The overall impact would be SMALL at ONS.
For alternative greenfield sites, the impact to the surface water would depend on the volume associated with the cooling system and characteristics of the receiving body of water. The impacts would be SMALL or MODERATE.
Groundwater. The facility's use of groundwater would not be impacted as a result of the variation between a once-through cooling system and a cooling tower-based system. Overall impacts would be SMALL at ONS.
For alternative greenfield sites, the impact to the groundwater would depend on the site characteristics, including the amount of groundwater available. The impacts would range between SMALL and LARGE.
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Air Quality
The air quality would be the same whether a cooling tower-based closed-cycle cooling system or a once-through cooling system was used. Overall impacts would be MODERATE at all locations.
  •  
Waste
The amount of waste and impacts resulting from waste disposal would be the same whether a cooling tower-based closed-cycle cooling system or a once-through cooling system was used. Overall impacts would be MODERATE at all locations.
  •  
Human Health
Human health effects would be the same whether a cooling tower-based closed-cycle cooling system or a once-through cooling system was used. Overall impacts would be SMALL at all locations.
  •  
Socioeconomics
Socioeconomic impacts would be the same whether a cooling tower-based closed-cycle cooling system or a once-through cooling system was used. Overall impacts would be MODERATE at Oconee, MODERATE to LARGE elsewhere.
  •  
Aesthetics
The closed-cycle cooling system alternative would add 15-m (50-ft) to 30-m (100-ft) tall mechanical draft towers and associated plumes. Mechanical draft towers introduce another noise source. This would be a small incremental change. Overall impacts would be MODERATE to LARGE at all locations.
  •  
Archaeological and Historical Resources
Minimal amounts of additional cultural resource studies would be required before construction of cooling towers. If towers were constructed on land that had already had cultural resource studies, further studies would not be necessary. This would be a minor incremental change. Overall impacts would be SMALL at all locations.
  •  
Environmental Justice
Environmental justice impacts would be the same whether a cooling tower-based closed-cycle cooling system or a once-through cooling system was used. Overall impacts are MODERATE at ONS, SMALL to MODERATE elsewhere.

8.2.2 Gas-Fired Generation

It was assumed that a replacement natural gas-fired plant would use combined cycle technology. In the combined cycle unit, hot combustion gases in a combustion turbine rotate the turbine to generate electricity. Waste combustion heat from the combustion turbine is routed through a heat-recovery steam generator to generate additional electricity. The size, type, and configuration of gas-fired generation units and plants currently operational in the United States vary and include simple-cycle combustion and combined-cycle units that range in size from 25 MW to 600 MW (EPA 1994). As with coal-fired technology, units may be configured and combined at a location to produce the desired amount of megawatts, and construction can be phased to meet electrical power needs.

Section 8.2.2.1 discusses the environmental impacts of converting the current ONS site to a natural gas-fired generation facility with once-through cooling and building a similar facility on a greenfield site. Differences in impacts with closed-cycle cooling are discussed in Section 8.2.2.2.

8.2.2.1 Once-Through Cooling System

Providing 2500 MW of replacement power with a combined cycle would require a minimum of 5 units. Natural gas typically has an average heating value of 3.7 × 107 J/m3 (1,000 Btu per cubic foot) (DOE 1996; EPA 1993), and it would be the primary fuel; the gas-fired alternative plant would burn approximately 1.24 J/m3-s (100 billion cubic feet per year). Low-sulfur No. 2 fuel oil would be the backup fuel (Duke 1998), but due to the relatively high cost of fuel oil, would not be the primary fuel for this technology. The discussion in this section addresses some of the differences in the impacts between gas- and oil-fired combustion turbine/combined cycle power plants.

As a surrogate for a similar-sized gas-fired alternative plant, the staff used Baltimore Gas and Electric's Perryman Power Plant and Polk Power Plant (BGE 1989; EPA 1984). The staff assumes that each unit would be less than 30 m (100 feet) high and would be designed with dry, low nitrogen oxides combusters, water injection, and selective catalytic reduction.

Each unit would exhaust through a 70-m (230-foot) stack after passing through heat-recovery steam generators. This stack height is consistent with EPA regulations (40 CFR 51.100), which address requirements for determining the stack height of new emission sources.

Natural gas would have to be delivered via pipeline. Approximately 60 ha (150 acres) would be disturbed during pipeline construction. The nearest gas pipeline large enough to support a new combined cycle plant is at Anderson, near Interstate 85, approximately 40 km (25 mi) from the Oconee site. Construction cost of installing a gas line to Oconee averages approximately $1 million per mile (Duke 1999b). Duke believes that the installation of a gas line to the Oconee site would not be economical and would require an additional 60 ha (150 acres) of land (Duke 1999b). To the degree existing rights-of-way could be used, the level of impact could be reduced.

Environmental impacts of conversion to the gas-fired generation option at both ONS and a "greenfield" site are summarized in the following text and are listed in Table 8.4.

  •  
Land Use
Gas-fired generation at the Oconee site would require converting a minimum additional 24 ha (60 acres) of the site and adjacent land to industrial use. Almost all would be used for the power block. Some, if not all of the land, would require clearing of wooded or vegetated areas since the existing industrial wooded area on the site is too small to accommodate the entire facility. An additional 60 ha (150 acres) would be disturbed during pipeline construction. Some additional land would also be required for backup oil storage tanks. Gas-fired generation land-use impact at the existing ONS site is MODERATE; the impact would noticeably alter habitat, but it would not destabilize any important attribute of the resource.

Table 8-4. Summary of Environmental Impacts from Gas-Fired Generation-Once-Through Cooling Alternative

  Oconee Site Alternative "Greenfield" Site

Impact Category

Impact Comments Impact Comments
Land Use MODERATE Additional 24 ha (60 acres) required for power block

Additional 60 ha (150 acres) disturbed for pipeline construction

Additional land for backup oil storage tanks

SMALL to MODERATE Up to 200 ha (500 acres) required for site pipelines and an estimated 16-km (10-mi) transmission line connection.

Additional land for backup oil storage tanks

Ecology MODERATE Constructed on land adjacent to Oconee site. Significant habitat loss due to pipeline construction SMALL to MODERATE Impact depends on location and ecology of the site
Water Use and Quality        
Surface Water SMALL 70% reduction in water flow SMALL to MODERATE Impact depends on volume and characteristics of receiving body of water
Groundwater SMALL Reduced groundwater withdrawals due to reduced workforce SMALL to LARGE Groundwater would be used for potable water only
Air Quality MODERATE Primarily nitrogen oxides MODERATE Same impacts as for Oconee site
-4300 MT/yr (4,700 tons/yr) with gas
-11,800 MT/yr (13,000 tons/yr) with fuel oil
Sulfur dioxide
-3600 MT/yr (4,000 tons per yr) with fuel oil, none with gas
Particulates
-2300 MT/yr (2,500 tons/yr) with fuel oil
-280 MT/yr (310 tons/yr) with gas
Carbon dioxide
-11 million MT/yr (12.5 million tons/yr) with fuel oil
-8 million MT/yr (9.2 million tons/yr) with gas
Waste SMALL Waste generation is 230 m3/yr, 2500 (ft3/yr) of spent catalyst with fuel oil, minor with gas SMALL Same impacts as for Oconee site
Human Health SMALL Impacts considered to be minor SMALL Same impacts as for Oconee site
Socioeconomics SMALL to MODERATE 500 to 750 additional workers during 3-year construction period; followed by reduction from 1700 persons to 300 persons (400 if fuel oil is used) MODERATE to LARGE Construction impacts would be relocated. Community near ONS would still experience reduction from 1700 persons to 0 persons.
Aesthetics SMALL to MODERATE Visual impact of stacks and equipment would be noticeable, but not as significant as coal option SMALL to MODERATE Alternate locations could reduce the aesthetic impact if siting is in an industrial area.
Archaeological and Historical Resources SMALL Only previously disturbed and adjacent areas would likely be affected SMALL Alternate location would necessitate cultural resource studies
Environmental Justice SMALL to MODERATE Impacts on low-income and minority populations should be similar to those experienced by the population as a whole. Impacts on housing are possible. SMALL to MODERATE Impacts vary depending on population distribution and makeup

Construction at a greenfield site would impact approximately 8 ha (20 acres) to 20 ha (50 acres) for offices, roads, parking areas, and a switchyard. The power block would require 25 ha (60 acres). Some additional land would also be required for backup oil storage. In addition, it is assumed that another 170 ha (424 acres) would be necessary for transmission lines (assuming the plant is sited 16 km [10 mi] from the nearest intertie connection), although this is uncertain and would depend on the actual plant location. Plants of this type are usually built very close to existing natural gas pipelines. Including the land required for pipeline construction, a greenfield site would require approximately 200 ha (500 acres). Depending on the transmission line routing, the greenfield site alternative could result in SMALL to MODERATE land-use impacts.

The GEIS estimated that land-use requirements for a 1000-MW gas-fired plant at a greenfield site would be SMALL (approximately 45 ha [110 acres] for the plant site), and that co-locating with a retired nuclear plant would reduce these impacts. The Duke land-use estimate is about the same as the GEIS, even though the plant is larger. The land-use change should not noticeably alter the overall site pattern for natural land use. Therefore, the impacts would be SMALL to MODERATE, depending on the length and routing of required pipelines and transmission lines.

  •  
Ecology
Siting gas-fired generation at the existing ONS site would have MODERATE ecological impact because the facility would be constructed partly on previously disturbed areas and would disturb relatively little acreage at the site. However, significant habitat (60 ha [150 acres]) would be disturbed by 40 km (25 miles) of pipeline construction (Duke 1999b). To the extent that existing rights-of-way could be used, the impact would be reduced. Ecological impacts would also be minimized by using the existing intake and discharge system. Past operational monitoring of the effects of once-through cooling at ONS have not shown significant negative impacts to Lake Keowee ecology, and this would be expected to remain unchanged. At the existing site, adding gas-fired generation would introduce construction impacts and new, albeit incremental, operational impacts.
The GEIS noted that land-dependent ecological impacts from construction would be SMALL unless site-specific factors should indicate a particular sensitivity and that operational impacts would be smaller than for other fossil fuel technologies of equal capacity. The staff has identified the gas pipeline as a site-specific factor that would make gas-fired alternative ecological impacts larger than for the license renewal. Therefore, in this case, the appropriate characterization of gas-fired generation ecological impacts would be MODERATE.
Construction at a greenfield site could alter the ecology of the site and could impact threatened and endangered species. These ecological impacts could be SMALL to MODERATE.
  •  
Water Use and Quality
Surface Water. The plant would use the existing ONS intake and discharge structures as part of a once-through cooling system; however, because cooling requirements would be less (70 percent reduction; EPA 1994), water quality impacts would continue to be SMALL.
Water quality impacts from sedimentation during construction was another land-related impact that the GEIS categorized as SMALL. The GEIS also noted that operational water quality impacts would be similar to, or less than, those from other centralized generating technologies. The staff has concluded that water quality impacts from coal-fired generation would be SMALL, and gas-fired alternative water usage would be less than that for coal-fired generation. Surface water impacts would remain SMALL; the impacts would not be detectable or be so minor that they would not noticeably alter any important attribute of the resource.
For alternative greenfield sites, the impact on surface water would depend on the volume and other characteristics of the receiving body of water. The impacts would be SMALL to MODERATE.
Groundwater. No variation would be expected in the amount of groundwater used since groundwater wells only are used to supply water for drinking and the restroom facility at the station baseball field as well as to supply irrigation water for site landscaping during the summer months (June through September). The groundwater impacts would be SMALL; the impacts would be so minor that they would not noticeably alter any important resource.
For alternative greenfield sites, the impact to the groundwater would depend on the site characteristics, including the amount of groundwater available. The impacts would range between SMALL and LARGE.
  •  
Air Quality
Natural gas is a relatively clean-burning fuel. Because the ONS is not or not nearly a nonattainment area for ozone, air quality impacts of gas-fired generation would not be of concern. Nitrogen oxides emissions from the gas-fired alternative would be 4300 MT (4700 tons) with gas to 11,800 MT (13,000 tons) with fuel oil per year.
The GEIS noted that gas-fired air quality impacts are less than other fossil technologies because fewer pollutants are emitted, and sulfur dioxide is not emitted at all. Emissions from the gas-fired alternative would be less than emissions from the coal-fired alternative. However, the gas-fired alternative would contribute nitrogen oxides emissions to an area that in the future may become a nonattainment area for ozone. Because nitrogen oxides contribute to ozone formation, the reduced nitrogen oxides emissions are still of future concern, and low nitrogen oxides combusters, water injection, and selective catalytic reduction could become regulatory-imposed mitigation measures.
For these reasons, the appropriate characterization of air impacts from a gas-fired plant would be MODERATE; the impacts, primarily nitrogen oxides, would be clearly noticeable, but would not be sufficient to destabilize air resources as a whole.
Siting the gas-fired plant elsewhere would not significantly change air quality impacts because the site could also be located in a greenfield area that was not a serious nonattainment area for ozone. In addition, the location could result in installing more or less stringent pollution control equipment to meet the regulations. Therefore, the impacts would be MODERATE.
  •  
Waste
There will be only small amounts of solid waste products (i.e., ash) from burning natural gas fuel. The GEIS concluded that waste generation from gas-fired technology would be minimal. Gas-firing results in very little combustion byproducts because of the clean nature of the fuel. Waste generation would be limited to typical office wastes. This impact would be SMALL; waste generation impacts would be so minor that they would not noticeably alter any important resource attribute.
Siting the facility at an alternate greenfield site would not alter the waste generation; therefore, the impacts would continue to be SMALL.
  •  
Human Health
The GEIS analysis mentions potential gas-fired alternative health risks (cancer and emphysema). The risk may be attributable to nitrogen oxides emissions that contribute to ozone formation, which in turn contributes to health risks. As discussed in Section 8.2.1 for the coal-fired alternative, legislative and regulatory control of the nation's emissions and air quality are protective of human health, and the appropriate characterization of gas-fired generation human health impacts would be SMALL; that is, human health effects would not be detectable or would be so minor that they would neither destabilize nor noticeably alter any important attribute of the resource.
Siting of the facility at an alternate greenfield site would not alter the human health effects that would be expected. Therefore, the impacts would be SMALL.
  •  
Socioeconomics
It is assumed that gas-fired construction would take place while ONS continues operation, with completion at the time that the nuclear plant would halt operations. Construction of the gas-fired alternative would take much less time than constructing other plants (NRC 1996). During the time of construction, the surrounding communities would experience demands on housing and public services that could have moderate impacts. After construction, the communities would be impacted by the loss of jobs; construction workers would leave, the nuclear plant workforce (1700) would decline through a decommissioning period to a minimal maintenance size, and the gas-fired plant would introduce a replacement tax base and about 300 (or for an oil-fired plant, 400) new jobs.
The GEIS concluded that socioeconomic impacts from constructing a gas-fired plant would not be very noticeable and that the small operational workforce would have the lowest socioeconomic impacts (local purchases and taxes) of any nonrenewable technology. Compared to the coal-fired alternative, the smaller size of the construction workforce, the shorter construction time frame, and the smaller size of the operations workforce would all reduce some of the socioeconomic impacts. For these reasons, gas-fired generation socioeconomic impacts would be SMALL to MODERATE; that is, depending on other growth in the area, socioeconomic effects could be noticed, but they would not destabilize any important attribute of the resource.
Construction at another site would relocate some socioeconomic impacts, but would not eliminate them. The community around the ONS site would still experience the impact of the loss of ONS operational jobs and the tax base. The communities around the new site would have to absorb the impacts of a moderate, temporary workforce and a small, permanent workforce. Therefore, the impacts would be MODERATE to LARGE, based on net job and tax base losses in the Oconee area. This impact is about the same in the Oconee area under the no-action alternative.
  •  
Aesthetics
The combustion turbines and heat-recovery boilers would be relatively low structures and would be screened from most offsite vantage points by intervening woodlands. The steam turbine building would be taller, approximately 30 m (100 feet) in height, and together with 70-m (230-foot) exhaust stacks, would be visible offsite.
The GEIS analysis noted that land-related impacts, such as aesthetic impacts, would be small unless site-specific factors indicate a particular sensitivity. As in the case of the coal-fired alternative, aesthetic impacts from the gas-fired alternative would be noticeable. However, because the gas-fired structures are shorter than the coal-fired structures and more amenable to screening by vegetation, the staff determined that the aesthetic resources would not be destabilized by the gas-fired alternative. For these reasons, the appropriate characterization of aesthetic impacts from a gas-fired plant would be SMALL to MODERATE; the impacts would be clearly noticeable, but would not destabilize this important resource.
Alternative locations could reduce the aesthetic impact of gas-fired generation if siting were in an area that was already industrialized. In such a case, however, the introduction of the steam generator building, stacks, and cooling tower plumes would probably still have a SMALL to MODERATE incremental impact.
  •  
Archaeological and Historical
The GEIS analysis noted, as for the coal-fired alternative, that gas-fired alternative cultural resource impacts would be small unless important site-specific resources were affected. Gas-fired alternative construction at the ONS site would affect a smaller area within the footprint of the coal-fired alternative. As discussed in 8.2.1, site knowledge minimizes the possibility of cultural resource impacts. Cultural resource impacts would be SMALL; that is, cultural resource effects would not be detectable or would be so minor that they would neither destabilize nor noticeably alter any important attribute of the resource.
Construction at another site could necessitate instituting cultural resource preservation measures, but impacts can generally be managed and maintained as SMALL. Cultural resource studies would be required for the pipeline construction and any other areas of ground disturbance associated with this alternative.
  •  
Environmental Justice
No environmental pathways have been identified that would result in disproportionately high and adverse environmental impacts on low-income and minority populations if a replacement gas-fired plant were built at the ONS site. Some impacts on housing availability and prices during construction might occur, and this could disproportionately affect the low-income or minority populations. The impacts would be SMALL to MODERATE. Impacts at other sites would depend upon the site chosen. If the replacement plant were built in Oconee County, the county's tax base would be largely maintained, and some potential negative socioeconomic impacts on the low-income or minority populations would be avoided. If the plant were built elsewhere, environmental justice impacts would be SMALL to MODERATE, depending on the population distribution.

8.2.2.2 Closed-Cycle Cooling System

Cooling for the gas-fired facility could also be accomplished by a closed-cycle system, which would also use the existing intake and discharge structures, but flow requirements would be 90 percent less than the once-through cooling system (Gilbert/Commonwealth 1996). This alternative would use mechanical draft cooling towers that are 15-m (50-ft) to 30-m (100-ft) tall. Based on Duke's experience with similar cooling towers at the Catawba Nuclear Station, cooling water consumption would be approximately 1.5 m3/s (24,000 gpm) (Duke 1999a) and land-use requirements for the towers would be 10 to 12 ha (25 to 30 acres). The closed-cycle cooling system alternative would introduce a cooling tower blowdown that would be higher in dissolved solids in comparison to Lake Keowee. Cooling tower operation would require more electrical power than the once-through alternative due to the modified pumping systems. Cooling towers would discharge a plume of water vapor and a small amount of cooling tower drift. Thermal rise would be less than with once-through cooling.

The incremental environmental impacts of converting to a closed-cycle cooling system at a gas plant are essentially the same incremental impacts of converting to a closed-cycle cooling system at a coal-fired plant. The impacts are discussed in Section 8.2.1.2 and are listed in Table 8-5.

8.2.3. Imported Electrical Power

"Imported power" means power purchased and transmitted from electric generation plants that the applicant does not own and that are located elsewhere within the region, nation, or Canada. Duke purchases substantial amounts of capacity on the wholesale market. For example, requests for proposals in 1995 yielded numerous short- and long-term proposals, from which Duke purchased options for 250 MW of capacity from PECO Energy for the period 1998 through 2001 (Duke 1998). In theory, importing (purchasing) additional power is a feasible alternative to ONS license renewal.

Table 8-5. Summary of Environmental Impacts of Gas-Fired Generation with Alternate
Cooling System (Cooling Towers with Closed-Cycle Cooling)

Impact Category Change in Impact Oconee Once-Through Cooling Comments
Land Use Minor change Uses an additional 10 to 12 ha (25 to 30 acres) for cooling tower construction
Ecology Minor change Additional impact to terrestrial ecology from cooling tower drift;

Reduced impact to aquatic ecology

Water Use and Quality    
Surface Water Minor change Blowdown has higher dissolved solids ; Reduced flow
Groundwater No change None
Air Quality No change None
Waste No change None
Human Health Small Impacts considered minor
Socioeconomics No change None
Aesthetics Minor change Addition of 30-m (100-ft) high draft towers including noise and vapor plume
Archaeology and Historical Resources Minor change Minimal studies (if necessary) before construction of cooling towers
Environmental Justice No change None

However, Duke points out that there is no assurance that sufficient capacity or energy would be available in the 2013 through 2034 time frame to replace the 2500 MW(e) base load generation. More importantly, regardless of the technology used to generate imported power, the generating technology would be one of those described in this SEIS and in the GEIS (probably coal, natural gas, nuclear, or Canadian hydroelectric). The GEIS, Chapter 8, description of the environmental impacts of other technologies is representative of the imported electrical power alternative to ONS license renewal.

According to the Energy Information Administration's (EIA's) International Energy Outlook 1998 (EIA 1997),

   Hydro Quebec has targeted the U.S. market for future sales growth. Hydro Quebec currently owns Vermont Gas and has signed a deal with Enron to market electricity in the Northeast while selling Enron's gas in Quebec. In April 1997, Hydro Quebec petitioned the FERC (Federal Energy Regulatory Commission) to sell electricity in the United States. In return, it would allow U.S. competitors to wheel electricity into Quebec. In November 1997, Hydro Quebec received FERC approval to sell power in the United States at market-based rates.

Depending on transmission availability, relative power costs, whether Canadian environmental and aboriginal rights controversies over the hydroelectric James Bay Project in Northern Quebec could be solved, and appropriate transmission agreements and facilities could be put in place, Hydro Quebec could be a future source of imported power. However, there would be significant environmental impacts in Northern Quebec.

8.2.4 Other Alternatives

This section identifies alternatives to ONS license renewal that are not feasible as direct replacements for ONS and describes why the alternatives are not considered feasible.

8.2.4.1 Wind

Wind power in the northwest area of South Carolina averages less than 100 w/m2 (9.3 w/ft2) at 10 m (33 ft) elevation or 200 w/m2 (18.6 w/ft2) at 50 m (164 ft) per hour. This is the lowest class on the 7-point scale (Wind Energy Resource Atlas, PNL-3195 [Zabransky et al. 1981]). The National Wind Technology Center, a branch of the U.S. Department of Energy, classifies potential wind farm resource areas from Power Class 1 through Power Class 7. Areas designated as Class 4 or higher are considered as areas of potential wind farm development using advanced wind turbine technology under development today. Power Class 3 areas may be suitable for future generation technology. The average annual capacity factor was estimated by the applicant at 21 percent in 1995 and projected at 29 percent in 2010 (Duke 1998). This low capacity factor compared with current base load technologies (Oconee's capacity factor is 78 percent) results from the intermittency of the wind resource (DOE/EIA-0561). Current energy storage technologies are too expensive to permit wind power to serve as a large base load. Based on the GEIS land-use estimate for wind power (the GEIS, Section 8.3.1, estimates 60,750 ha [150,000 acres] per 1000 MW(e) for wind power), replacement of ONS generating capacity, even assuming ideal wind conditions, would require dedication of almost 150,000 ha (375,000 acres) in the area in which ONS is located. Given the amount of land required, a large greenfield site would be necessary, which would result in a LARGE environmental impact.

8.2.4.2 Solar

Solar power technologies, photovoltaic and thermal, cannot currently compete with conventional fossil-fueled technologies in grid-connected applications due to high costs per kilowatt of capacity (DOE 1995). The average capacity factor of photovoltaic cells is about 25 percent, and the capacity factor for solar thermal systems is about 25 percent to 40 percent. Energy storage requirements prevent the use of solar energy systems as base load. According to the GEIS, land requirements are also high-- 14,000 ha (35,000 acres) per 1000 MW(e) for photovoltaic and 6000 ha (14,000 acres) per 1000 MW(e) for solar thermal systems. Neither type of solar electric system would fit at the ONS site, and either would have large environmental impacts at a greenfield site.

8.2.4.3 Hydropower

Hydroelectric power has an average annual capacity factor of 46 percent. As GEIS, Section 8.3.4, points out, hydropower's percentage of the country's generating capacity is expected to decline because hydroelectric facilities have become difficult to site as a result of public concern over flooding, destruction of natural habitat, and destruction of natural river courses. GEIS, Section 8.3.4, estimates land use of 400,000 ha (1 million acres) per 1000 MW(e) for hydroelectric power. Based on this estimate, replacement of ONS generating capacity would require flooding more than 6700 km2 (2600 mi2), a LARGE impact on land use. Due to the lack of locations for siting a hydroelectric facility large enough to replace ONS, local hydropower is not a feasible alternative to ONS license renewal on its own. See Section 8.2.3 for a discussion of Canadian hydropower.

8.2.4.4 Geothermal

Geothermal has an average capacity factor of 90 percent and can be used for baseload power where available. However, as illustrated by the GEIS, Figure 8.4, geothermal plants might be located in the western continental United States, Alaska, and Hawaii where hydrothermal reservoirs are prevalent, but there is no feasible location for 2500 MW(e) of geothermal capacity to serve as an alternative to ONS license renewal.

8.2.4.5 Wood Energy

A wood burning facility can provide base load power and operate with an average annual capacity factor of around 70 to 80 percent and with 20 to 25 percent efficiency (GEIS, Section 8.3.6). The fuels required are variable and site-specific. A significant barrier to the use of wood waste to generate electricity is the high delivered fuel cost. States with significant wood resources, such as California, Maine, Georgia, Minnesota, Oregon, Washington, and Michigan, benefit from using local resources. The pulp, paper, and paperboard industries, which consume large quantities of electricity, are the largest consumer of wood and wood waste for energy, benefitting from the use of waste materials that could otherwise represent a disposal problem. The larger wood waste power plants are only 40 to 50 MW(e) in size. Estimates in the GEIS suggest that the overall level of construction impact should be approximately the same as that for a coal-fired plant, although facilities using wood waste for fuel would be built at smaller scales. Like coal-fired plants, wood-waste plants require large areas for fuel storage and processing and involve the same type of combustion equipment. Duke estimates that a rough construction cost for a 2500 MW(e) plant in the Oconee area would be about $2400/KW, which would not be competitive for baseload power (Duke 1998).

8.2.4.6 Municipal Solid Waste

The initial capital costs for municipal solid waste plants are greater than for comparable steam turbine technology at wood waste facilities. This is due to the need with municipal solid waste for specialized waste separation and handling equipment. The decision to burn municipal waste to generate energy is usually driven by the need for an alternative to landfills rather than by energy considerations. The use of landfills as a waste disposal option is likely to increase in the near term; however, it is unlikely that many landfills will begin converting waste to energy because of unfavorable economics, particularly with electricity prices declining (DOE 1995). Therefore, municipal solid waste would not be a feasible alternative to ONS license renewal, particularly at the scale required.

8.2.4.7 Other Biomass-Derived Fuels

In addition to wood and municipal solid waste fuels, there are several other concepts for fueling electric generators, including burning energy crops, converting crops to a liquid fuel such as ethanol (ethanol is primarily used as a gasoline additive for automotive fuel), and gasifying energy crops (including wood waste). The GEIS points out that none of these technologies has progressed to the point of being competitive on a large scale or of being reliable enough to replace a baseload plant such as ONS. For these reasons, such fuels do not offer a feasible alternative to ONS license renewal. In addition, these systems have LARGE impacts on land use.

8.2.4.8 Oil

Oil is not considered a stand-alone fuel because it is not cost-competitive when natural gas is available. The cost of oil-fired operation is about eight times as expensive as nuclear and coal-fired operation. In addition, future increases in oil prices are expected to make oil-fired generation increasingly more expensive than coal-fired generation (DOE 1996). For these reasons, oil-fired generation is not a feasible alternative to ONS license renewal nor is it likely to be included in a mix with other resources, except as a back-up fuel.

8.2.4.9 Advanced Nuclear Power

Work on advanced reactor designs has continued, and nuclear plant construction continues overseas. However, the cost of building a new nuclear plant and the political uncertainties that have historically surrounded many nuclear plant construction projects are among the factors that have led energy forecasters such as EIA to predict no new domestic orders for the duration of current forecasts (through the year 2010 [DOE 1996]). For these reasons, new nuclear plant construction is not considered a feasible alternative to ONS license renewal.

8.2.4.10 Fuel Cells

Phosphoric acid fuel cells are the most mature fuel cell technology, but they are only in the initial stages of commercialization. Two-hundred turnkey plants have been installed in the United States, Europe, and Japan. Recent estimates suggest that a company would have to produce about 100 MW of fuel cell stacks annually to achieve a price of $1000 to $1500 per kilowatt (DOE 1999). However, the current production capacity of all fuel cell manufacturers only totals about 60 MW per year. Therefore, the staff considers fuel cells not to be a feasible alternative to license renewal at this time.

8.2.4.11 Delayed Retirement

Duke's 1997 Integrated Resource Plan (IRP) (Duke 1998) discusses the strategy for meeting overall energy needs for the next 15 years. The IRP discusses decision dates (as opposed to retirement dates) for the following proposed combustion turbine generating requirements: 303 MW(e) in 2004; 88 MW(e) in 2005; 85 MW(e) in 2006. The IRP also discusses retirement of the following fossil generation: 276 MW(e) in 2010 and 438 MW(e) in 2011. The period of time evaluated for the IRP does not extend to the retirement dates for Oconee.

However, the delayed retirement of the above generation resources could not be used to replace the 2500 MW(e) generated at Oconee. In part because of their high operating cost, combustion turbines and small fossil units are used for peaking and intermediate generation. Therefore, it would not be feasible for the combustion turbines and small fossil plants listed above to replace base load generation. Additionally, it is unlikely that these fossil units could operate economically for an additional 20 years after the current decision dates. Duke does not have any plans to retire any of its base load units. Therefore, delayed retirement of base load fossil units could not be used as an alternative to license renewal.

8.2.4.12 Utility-Sponsored Conservation

Demand-side measures have been included in the past IRPs, and Duke currently has several general demand-side actions in their current plan (Duke 1998). These measures are discussed below.

   Focus on Education - to help maintain competitive electricity rates, Duke is shifting the energy efficiency focus from an emphasis on energy efficiency options that are large, high-cost, and incentive-based to less costly education-based options.
Implementation of Demand-Side Competitive Bidding - Duke assessed the potential benefits of paying a third-party or customer to design and/or market demand-side resource options. Duke has entered into contracts with four bidders for a total projected resource of 4.7 MW(e).

Demand-side options currently used at Duke include the following:

   Energy efficiency - High energy (HE) compressed air systems and HE motor systems and replacements
Interruptibles - Residential load control ride: A/C and water heating, power service rider, generator control rider
Load shifts - Residential water heating, controlled/submerged
Strategic Sales - Electrotechnology strategy, HE food service appliance, nonresidential space heating
Energy Efficiency and Strategic Sales - New residential housing program, existing residential housing program, and nonresidential heat pump program.

Currently, the demand side measures are expected to account for 950 MW(e) in 1999. This number is projected to decrease to 750 MW(e) in 2004. In addition, the demand side measures already are included in the applicant's growth projections. The applicant considers it unlikely that another cost-effective 2500 MW(e) can be found to replace ONS. Therefore, the conservation option is not considered a reasonable replacement for the license renewal alternative.

8.2.4.13 Combination of Alternatives

Even though individual alternatives to ONS might not be sufficient on their own to replace ONS due to the small size of the resource (hydro) or lack of cost-effective opportunities (e.g., for conservation), it is conceivable that a mix of alternatives might be cost-effective. For example, if some additional cost-effective conservation opportunities could be found and combined with a smaller imported power or natural gas-fired alternative, it might be possible to reduce some of the key environmental impacts of alternatives. However, it is unlikely that the environmental impact of such a hypothetical mix could be reduced below SMALL (see Table 8-6). In comparison, the impacts of renewing the ONS licenses are SMALL on all dimensions.

Table 8-6. Summary of Environmental Impacts of 500 MW(e) Demand-Side Measures, Plus 1200 MW(e) Gas-Fired Generation (Once-Through Cooling)

  Oconee Site Alternative "Greenfield" Site

Impact Category

Impact Comments Impact Comments
Land Use SMALL Additional 24 ha (60 acres) required for power block

Additional 60 ha (150 acres) disturbed for pipeline construction

Additional land for backup oil storage

SMALL to MODERATE Up to 200 ha (500 acres) required for site plus transmission line, backup fuel tanks, pipeline
Ecology SMALL Constructed on land adjacent to Oconee site. Significant habitat loss due to pipeline construction SMALL to MODERATE Impact depends on location and ecology of the site
Water Use and Quality        
Surface Water SMALL >70% reduction in water flow SMALL to MODERATE Impact depends on receiving body of water
Groundwater SMALL Reduced groundwater withdrawals due to reduced workforce SMALL to MODERATE Groundwater would be used for potable water only
Air Quality SMALL to MODERATE Primarily nitrogen oxides

SMALL to MODERATE Same impacts as for Oconee site
Waste SMALL Minor waste generation with gas (oil not evaluated) SMALL Same impacts as for Oconee site
Human Health SMALL Impacts considered to be minor (see discussion of gas-fired alternative) SMALL Same impacts as for Oconee site
Socioeconomics SMALL to MODERATE 500 to 750 additional workers during 3-year construction period; followed by a reduction in employment from 1700 persons at ONS to 300 persons (499 if fuel oil is used) MODERATE to LARGE Construction impacts would be relocated. Community near ONS would still experience reduction from 1700 workers to 0. Other community gains 300 workers
Aesthetics SMALL to MODERATE Visual impact of stacks would be noticeable, but less so than for the gas-fired alternative SMALL to MODERATE Alternate locations could reduce aesthetic impact if siting is in an industrial area
Archaeological and Historic Resources SMALL Only previously disturbed and adjacent areas would likely be affected SMALL Alternate location would necessitate cultural resource studies
Environmental Justice SMALL to MODERATE Impacts on low-income and minority populations should be similar to those experienced by the population as a whole. Impacts on housing are possible. SMALL to MODERATE Impacts vary depending on population distribution and makeup

8.3 References

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40 CFR 50.9, "National primary and secondary ambient air quality standard for nitrogen dioxide."

40 CFR 50.10, "Postconstruction environmental reports."

40 CFR 51.100, "Definitions."

Baltimore Gas and Electric (BGE). 1989. Perryman Power Plant Certification of Public Convenience and Necessity, Environmental Review Document, Vol-2, Baltimore Gas and Electric, Baltimore, Maryland.

Clean Air Act (CAA), as amended, 42 USC, 7401 et seq.

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

Duke Energy Corporation. 1999a. Letter from M. S. Tuckman, Duke Energy Corporation to U.S. 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. Follow-up to Staff's Request for Additional Information Dated December 29, 1998, Related to the Environmental Portion of the Review of the License Renewal Application for Oconee Units 1, 2, and 3.

Energy Information Administration (EIA). 1997. Annual Energy Outlook 1998, Table A2. DOE/EIA-0383 (98), Washington, D.C.

Gilbert/Commonwealth. 1996. Update to Calvert Cliffs Nuclear Power Plant Units 1 and 2 Cooling Tower System Study.

Maryland Department of Natural Resources (MDNR). 1999. Maryland Power Plants and the Environment: A review of the impacts of power plants and transmission has on Maryland's natural resources. PRRP-CEIS-10, Maryland Power Plant Research Program, Annapolis, Maryland.

South Carolina Department of Health and Environmental Control (SCDHEC). 1998. South Carolina Air Quality Annual Report, Volume XVII 1997. Columbia, South Carolina.

U.S. Department of Energy (DOE). 1993. Renewable Resources in the U.S. Electricity Supply. DOE/EIA-0561, U.S. Department of Energy, Energy Information Administration, Washington, D.C.

U.S. Department of Energy (DOE). 1995. Electric Power Annual. U.S. Department of Energy, Energy Information Administration, Washington, D.C.

U.S. Department of Energy (DOE). 1996. Annual Energy Outlook; 1996 with Projections to 2015. DOE/EIA-0383(96), U.S. Department of Energy, Energy Information Administration, Washington, D.C.

U.S. Department of Energy Information Administration (EIA). 1997. Annual Energy Outlook 1998, Table A2, DOE/EIA-0383(98), U.S. Department of Energy, Washington, D.C.

U.S. Department of Energy (DOE). 1999. Advanced Fuel Cell Systems - A Revolutionary Power Technology, U.S. Department of Energy/Fossil Energy-Fuel Cell Power Systems overview. http://www.fe.doe.gov/coal-power/fc_sum.html. (Accessed August 4, 1999).

U.S. Environmental Protection Agency (EPA). 1993. Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources. EPA, AP-42, U.S. Environmental Protection Agency, Washington, D.C.

U.S. Environmental Protection Agency (EPA). 1994. Final Environmental Impact Statement, Volume I: Tampa Electric Company - Polk Power Station. EPA 904/9-94, U.S. Environmental Protection Agency, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1988. Final Generic Impact Statement on Decommissioning of Nuclear Facilities. NUREG-0586, U.S. Environmental Protection Agency, Washington, D.C.

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

Zabransky, J., J. M. Vilardo, J. T. Schakenback, D. L. Elliott, W. R. Barchet, and R. L. George. 1981. Wind Energy Resource Atlas: Volume 6-The Southeast Region. PNNL-3195 WERA-6, Pacific Northwest Laboratory, Richland, Washington.

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