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Nuclear Power Generation: Water Needs and Environmental Impacts

Nebiyu Tiruneh, Richard Raione, Hosung Ahn, Mark McBride, Joseph Giacinto

United States Nuclear Regulatory Commission

2011 GROUNDWATER PROTECTION COUNCIL ANNUAL FORUM Atlanta, GA

September 24-28, 2011

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Outline Introduction The Regulatory Framework

• Hydrologic Safety Review • Hydrologic Environmental Review

Nuclear Power Generation in the United States Hydrologic Safety Analysis of Radioactive Liquid Effluents Conceptual Site Models and Modeling Thermoelectric Power Generation and Water Needs

• Projected Growth in Thermoelectric Energy Generation • Thermoelectric Power Generation Water Needs

• Water Withdrawal and Water Consumption • Regional Climatic Variability and Water Demand

Availability of Fresh Water Sources • Water Withdrawal Trends

Power Generation Impacts on Water Resources • Thermal Pollution • Radioactive Effluents

Conclusions

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Introduction Brief History of the U.S. NRC

Atomic Energy Act of 1954 – under section 103 enabled licensing of nuclear power plants for civilian use.

The Energy Reorganization Act of 1974 - establishment of the U.S. NRC in 1975.

The Commission led by five appointed commissioners, one of them is appointed Chairman.

Approved many licenses and currently there are 104 plants in operation.

Operating plants licensed under 10 CFR Part 50 – construction permit and operating license.

10 CFR Part 52 adopted in 1989 has provisions for COL, ESP, and DC

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Introduction…Terms COL – Combined Operating License

provides approval for construction and operation valid for a period of 40 years from the date of the Commission

finding. COL can be renewed for an additional 20 years at the end of the

initial licensing period. ESP – Early Site Permit

provides approval for one or more sites independent of a reactor design.

the review includes site safety, environmental protection, and emergency planning, independent of a specific nuclear reactor design or application for a construction permit or combined license.

is valid for 10 to 20 years from the date of issuance, and can be renewed for an additional 10 to 20 years.

DC – Design Certification approval of standardized reactor design.

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The Regulatory Framework • Safety Review: Determining the safe operation of the proposed

plant under a variety of adverse conditions with appropriate provisions for mitigation and emergency procedures.

• Environmental Review: Performed to assess the impacts of construction and operation of a plant on the environment.

• Regulations: Atomic Energy Act, Regulations (10 CFR), the National Environmental Policy Act (NEPA). Clean Water Act,…

• Guidance Documents: Standard Review Plan (SRP), Environmental Standard Review Plan (ESRP), Regulatory Guides (RG), National Standards, and scientific analyses.

• Cooperating Agencies: Federal Agencies such as EPA, and USACE

• Public Involvement: Scoping meetings, opportunity to intervene through hearings.

• Decision: The Commission, the Advisory Committee on Reactor Safeguards (ACRS). The Atomic Safety Licensing Board Panel (ASLBP).

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Hydrologic Safety Review

• 2.4.1 Hydrologic Description – Interface of the plant with he hydrosphere, causal mechanisms, Conceptual Site Models (CSM)

• 2.4.2 Floods – Flood causing mechanisms, history, onsite flooding • 2.4.3 Probable Maximum Flood (PMF) on Streams and Rivers • 2.4.4 Potential Dam Failures • 2.4.5 Probable Maximum Surge and Seiche Flooding • 2.4.6 Probable Maximum Tsunami Flooding • 2.4.7 Ice Effects • 2.4.8 Cooling Water Canals and Reservoirs • 2.4.9 Channel Diversions • 2.4.10 Flooding Protection Requirements • 2.4.11 Low Water Considerations • 2.4.12 Groundwater – Regional and local, aquifers, water use and

quality • 2.4.13 Accidental Releases of Radioactive Liquid Effluents in

Ground and Surface Waters – Postulated failure of a LWMS tank, pathways, estimation of concentration and dose

• 2.4.14 Technical Specifications and Emergency Operation Requirements

Hydrologic Environmental Review

• 2.3 Water: Hydrology, Water Use, and Water Quality • 3.0 Plant Description: Plant Water Use, Water Consumption,

Water Treatment • 4.0 Environmental Impacts of Construction: Water-Related

Impacts, Hydrologic Alterations, Water-Use Impacts. • 5.0 Environmental Impacts of Station Operation: Water-

Related Impacts, Hydrologic • 6.0 Alterations and Plant Water Supply: Water-Use Impacts,

Environmental Measurements and Monitoring Programs, Thermal Monitoring, Hydrological Monitoring, and Chemical Monitoring

• 9.0 Alternatives to the Proposed Action: No-Action Alternative, Energy Alternatives, Alternative Sites, Alternative Plant and Transmission Systems 7

Nuclear Power Generation in the United States

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Consistent growth until mid-1990s

Nuclear Share of Electricity Net Generation in the U.S.

Operation of Nuclear Power Plants Under Original Licensing Regulations (10 CFR 50)

First wave of COLA applications in 2007. By the end of 2010: Applications for 18 COLAs to operate

28 new reactors were received. All under review.

5 design certification applications are being reviewed.

4 ESPs were reviewed and issued.

New Nuclear Power Plant Applications Under 10 CFR 52

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Hydrologic Safety Analysis of Radioactive Liquid Effluents

• Human Dose – ECL set by regulation • Postulated accident scenario: Postulated failure of a

tank located outside of the containment building and the subsequent release of its contents to the environment.

• Pathway to the nearest potable water source: • The nearest potable water supply, located in an

unrestricted area, for direct human consumption or • Indirectly through animals, crops, and food

processing. • Technical Analysis: Adequate characterization of:

– subsurface and aquifers, – liquid radioactive effluent release scenario, – screening of the radionuclide constituents, and – CSMs and plausible pathways.

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Conceptual Site Models (CSMs) • Regulatory Goal:

providing reasonable assurance that the reactor interfaces with the hydrosphere correctly and operates safely without posing a threat to public health and safety and the environment.

• CSMs describe qualitatively and quantitatively how the system functions and the governing processes operate.

Depending on the level of complexity involved and the amount of information desired, the dimensional representation of CSMs could be 1-D, 2-D cross sectional, 2-D planar, or 3-D.

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CSM Example

PROPOSED FINAL GRADESOIL AND SAPROLITE

AUXILIARY

BUILDING

AUXILIARY

HOLDING

POND

GROUNDWATER FLOW DIRECTION

RADIOACTIVE LIQUID EFFLUENT RELEASED

FROM RUPTURED HOLDUP TANK

SOIL AND SAPROLITE

EFFLUENT

HOLDING

TANK

BEDROCK

PARTIALLY WEATHERED ROCK

IN-SITU FILL

BASE MAT

PARTIALLY WEATHERED ROCK

RIVER

Conceptual model for evaluating radionuclide transport in groundwater (modified from WSL COLA) NOT TO SCALE

FILL

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CSM to Predictive Modeling…

Yes

No

Analytical Model

Numerical Model

Mathematical Model

Conceptual Site Model

Alternate Pathway 2 Alternate Pathway 1 Alternate Pathway “n”

Uncertainty Analysis

Conservatism Acceptable?

Geologic and

Hydrogeologic Data

Hydrologic Data Site Engineering Design Data

Scenarios Source Term Potable Water Source

START

The Energy Water Nexus

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Water is essential

to produce energy

and power

Thermoelectric cooling Hydropower Minerals extraction/mining Fuel Production (fossil fuels, biofuels, etc) Emission control

Energy is

essential for

water utilization

Storing Pumping Treating Distributing Recreational use Conjunctive use Surface and Ground water

Thermoelectric Power Generation and Water Needs

• Thermoelectric power generation relies heavily on availability of large quantities of freshwater resources.

• Approximately 89% of the energy produced in the U.S. uses thermoelectric systems (AEO, 2011)

• Thermoelectric power plants account for 39% of total U.S. freshwater withdrawals (GAO, 2009).

• Water consumption depends on cooling system type • Three types of cooling system designs in use by

thermoelectric plants; once-through, closed-loop (wet recirculating), and dry cooling systems.

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Net Electricity Generation: 2009

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Nuclear 20.2%

Natural gas 23.3%

2009 Total net generation: 3,953 billion kWh

Coal 44.6%

2009 Non-hydro renewable net generation: 141 billion kWh

Geothermal: 0.4%

Other biomass: 0.5%

Wood and wood-derived fuels: 0.9%

Other renewable

3.6%

Conventional hydroelectric

6.9%

Other 0.3%

Wind: 1.8%

Solar thermal and photovoltaic (PV): <0.1%

Petroleum 1.0%

Other gases 0.3%

70% fossil fuels, 20% nuclear, and 10% renewable Source: EIA Electric Power Monthly, October 2010

Trend of Electricity Consumption

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-2

0

2

4

6

8

10

12

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1950 1960 1970 1980 1990 2000 2015 2025 2035

Projection

projected electricity consumption grows by 30%, the rate of growth has slowed

percent growth (3-year rolling average)

History

Period Annual Growth 1950s 9.8 1960s 7.3 1970s 4.7 1980s 2.9 1990s 2.4 2000-2009 0.5 2009-2035 1.0

Source: EIA, Annual Energy Outlook 2011

Trends in Thermoelectric Power Water Withdrawals and Population

17 1980 was the year with the highest withdrawal on record

Thermoelectric Water Withdrawals in 2005

18 Source: USGS

Total Freshwater Withdrawals

Thermoelectric Power Water Withdrawals

Groundwater Withdrawals

Surface Water Withdrawals

Water Withdrawal and Consumption for Various Power Generation Technologies

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Source: GAO 2006 and EPR 2002

Plant-type Process Steam Withdrawal Consumption Withdrawal Consumption

Mining 5–74

Slurry 110–230 30–70 OL Cooling 20,000– 50,000 ~300 CL Tower 300–600 300–480 CL Pond 500–600 ~480 Dry 0 0

Nuclear Mining and Processing 45–150

Nuclear OL Cooling 25,000– 60,000 ~400 Nuclear CL Tower 500–1,100 400–720 Nuclear CL Pond 800–1,100 ~720 Nuclear Dry 0 0

Geothermal Steam CL Tower ~2000 ~1400 Solar trough CL Tower 760–920 760–920 Solar tower CL Tower ~750 ~750

Other

Natural Gas Supply ~11

OL Cooling 7,500– 20,000 100CL Tower ~230 ~180 Dry 0 0

Coal IGCC* CL Tower ~250 ~200 Hydro-electric Evaporation 4500 (ave)

7–10 + 130 (process water)**

Other Use Steam Condensing Water intensity (gal/MWhe)

Coal

Natural Gas CC

Fossil/ biomass/ waste ~30**

~30**

Not available 8** 8**

7–10**

Mining ofcoalconsumes0.07 to 0.26billiongallonsper day

Thermoelectricpowergenerationwithdraws136 billiongallonsper dayandconsumes3.3 billiongallonsper day

OL = Open loop cooling, CL = Closed Loop Cooling, CC = Combined Cycle *IGCC = Integrated Gasification Combined-Cycle, includes gasification process water Other Use includes water for other cooling loads such as gas turbines, equipment washing, emission treatment, restrooms, etc. **References did not specify whether values are for withdrawal or consumption.

Thermoelectric Generation Water Needs Estimates (using AEO 2010 regional projections for capacity additions and retirements)

• Case 1 – Additions and retirements are proportional to current water source and type of cooling system.

• Case 2 – All additions use freshwater and wet recirculating cooling, while retirements are proportional to current water source and cooling system.

• Case 3 – 90% of additions use freshwater and wet recirculating cooling, and 10% of additions use saline water and once-through cooling, while retirements are proportional to current water source and cooling system.

• Case 4 – 25% of additions use dry cooling and 75% of additions use freshwater and wet recirculating cooling. Retirements are proportional to current water source and cooling system.

• Case 5 – Additions use freshwater and wet recirculating cooling, while retirements are proportional to current water source and cooling system. 5% of existing freshwater once-through cooling capacity is retrofitted with wet recirculating cooling every five years starting in 2015.

20 Source: Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements

September 2010 DOE/NETL

Thermoelectric Water Needs - Forecasts

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Withdrawal is expected to decline for cases 2 through 5. Consumption is expected to increase for all 5 cases.

Withdrawal

Consumption

Regional Climatic Variability and Water Demand

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Total, surface-water, and ground-water withdrawals, 2000

23 Source: USGS

Drought

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Regional Drought Frequencies, 1895-1995

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Percent of time in severe and extreme drought

Source: Government Accountability Office (GAO, 2003) - National Drought Mitigation Center University of Nebraska Lincoln

< 5% 5% - 9.9% 10% - 14.9% 15% - 19.9% ≥ 20%

Availability of Freshwater Sources

26 Source: U.S. Geological Survey USGS Circular 1323 with original data source cited as the American Water Resources Association

Cumulative monthly precipitation potential evapotranspiration

From 1934-2002 in/yr (#counties)

Extent of State Shortages Likely over the Next Decade under Average Water Conditions

27 Source: Government Accountability Office (GAO) analysis of state water managers’ responses to GAO survey. GAO 2003

Statewide (2) Regional (16)

No response or uncertain (5)

None (9)

Local (18)

Operating Nuclear Power Plants and Years of Operation

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Projected Locations of New Nuclear Power Reactors

Energy –Water Conflicts?

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1

2

3

4

5 6

7

8

9 10

11 12

13

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Source: Energy Demands on Water Resources. GAO 2006.

Tennessee Governor imposed moratorium in 2002 on installation of new merchant plants because of cooling constraints

Brownsferry NPP on Tennessee River, often high water temperature at intake (86)F close to discharge (90F)

Low water on Missouri River leads to high pumping energy, low efficiency, load reduction and plant shutdown

Arizona rejected permitting for NPP because of impact on local aquifer

South Dakota Governor called for a summit to discuss drought-induced low flows on the Missouri River and the impacts on irrigation, drinking-water systems, and power plants

University of Texas researchers said power plants would have to curtail production if 20th century drought conditions recurred (Clean Air Task Force, 2004a).

Idaho opposed two proposed power plants because of impact on aquifer

Water Withdrawal Trends

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Thermoelectric Power Generation Impacts on Water Resources

Quantity • Reduced water

availability for competing uses.

• Hydrologic alterations (diversion, discharge, ponding, etc)

• Water use impacts

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Quality • Thermal • Hydrodynamic • Hydrologic alterations

(erosion, sedimentation, etc)

• Chemical • Biological • Radiological • Ecological (wetlands,

aquatic life, etc)

Nuclear Power Generation Potential Impacts on Water Resources

• Quantity: Reduced water availability depending on type of cooling system significant withdrawals.

• Hydrological: Alterations for constructing intake and discharge structures.

• Hydrological: Alterations for onsite and offsite water storage.

• Hydrological: Alterations for cooling tower and UHS construction.

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Nuclear Power Generation Potential Impacts on Water Resources

• Ecological - Quality: Impacts on aquatic and terrestrial ecology, such as wetlands, fish, wildlife.

• Radiological - Quality: Accidental and normal operational releases of radioactive liquid effluents into the hydrologic system and gaseous effluents through atmospheric dispersion.

• Thermal - Quality: Release of thermally elevated water into the hydrologic cycle.

• Hydrodynamic – Quality: Alterations to flow characteristics and changes in flow regime. 34

Radioactive Effluents

• All light-water-cooled reactors release small quantities of radioactive materials to the environment.

• Criteria for doses from liquid and gaseous effluents are for any individuals in the unrestricted area from all pathways of exposure – keep dose below level that has adverse impact on human health.

• Doses to the population within 80 km (50 mi) radius are assessed before a plant becomes operational to meet 10 CFR 50, Appendix I.

• Doses to humans from accidental release through all pathways are assessed prior to operation to determine compliance with 10 CFR 20, Appendix B limits

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Conclusions • Increase in power demand under most scenarios considered

by Annual Energy Outlook (AEO) reports. • Increase in water need for thermoelectric power generation. • Compared to fossil fuel based plants nuclear is widely

accepted as having significantly lower greenhouse gas (GHG) emission.

• Climatic variability likely stress in many parts of the U.S., but mainly the south and southwest.

• Concentration of nuclear power generation plants in the south, southeast and northeast of the country.

• Thermal stresses are likely to occur during low flow season. • Regional water impacts could be significantly different from

the national average indicators.

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• Improved designs such as passive designs and hybrid cooling will reduce the consumption of water and thermal stresses.

• Future need to investigate the performance of thermoelectric plants under changing climatic conditions.

• Regulatory tools are effective to restrict thermal pollution and dose to humans and biota, but continued monitoring is essential.

• Modeling and monitoring are highly effective tools in maintaining – the desirable level of water quality from thermal and

radionuclide stresses. – Understanding pathways and implementing mitigation

measures in the event of an accident

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Conclusions

Examples of regulatory requirements 10 CFR Part 50 Appendix I “Numerical Guides for Design

Objectives and Limiting Conditions for Operation to Meet the Criterion "As Low as is Reasonably Achievable" for Radioactive Material in Light-Water-Cooled Nuclear Power Reactor Effluents”

10 CFR 20 Appendix B “Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage”

• The concentration values are equivalent to the radionuclide concentrations which, if inhaled or ingested continuously over the course of a year, would produce a total effective dose equivalent of 0.05 rem (50 millirem or 0.5 millisieverts).

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DISCLAIMER The views expressed in this presentation are those of the authors and do not necessarily reflect the official position of

the U.S. Nuclear Regulatory Commission

Thank You

U.S. Nuclear Regulatory Commission http://www.nrc.gov

Contact:

Nebiyu Tiruneh: nebiyu.tiruneh@nrc.gov

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Thank You

U.S. Nuclear Regulatory Commission http://www.nrc.gov

Contact:

Nebiyu Tiruneh: nebiyu.tiruneh@nrc.gov