Meteorological Considerations for Nuclear Power Plant Siting

and Licensing

George C. Howroyd, Ph.D., P.E.CH2M HILL

Paul B. Snead, R.E.M.Progress Energy

• Projected need for new generation by 2030 is >350,000 MW, the equivalent of hundreds of new power plants

• Increasing concern over CO2 emissions is putting increasing environmental pressure on fossil powered generation

• Nuclear power generation produces no CO2 emissions and represents 75% of the power generated in the U.S. with no CO2 emissions

• Current nuclear generation is only 20% of current U.S. capacity

• No new U.S. nuclear plants have been licensed in over 25 years

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Background

• New plant licensing has historically been an onerous processo Lengthy (10+ years in many cases)o Costlyo Site/reactor specific

• Recent initiatives have streamlined the process (DOE’s Nuclear Power 2010 Program) but is still estimated to take several years to license a plant

• DOE financial incentives have spurred significant interest and activity

3

Background (Cont’d)

• New license applications are currently under review or are being prepared:o 23 applications for more than 34 new reactors

5 submitted to NRC in 2007 (8 units) 13 expected to be submitted in 2008 (19 units) 5 projected in 2009/2010 (7 units) Represents only 10 percent of projected demand through

2030 (assuming all are built) Source: U.S. NRC web site

o Most are in southeastern U.S.o Others are being considered

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Recent New Plant Licensing Activity

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Potential for New Nuclear

Existing PlantsPlant Re-Starts

ESP SitesNew Plants

Graphic provided by NEI and updated by Progress Energy with latest utility announcements

Potential for New Nuclear

• Role of Meteorology: To help support the conclusion that a plant can be constructed and operated without undue risk to health and safety

• NRC has extensive regulatory requirements pertaining to climatology and meteorology:

o Regional Climatology – Used to identify limiting parameters that determine safe design and operation

o Local Meteorology – Used to assess the impact of facility operation on local meteorological conditions

o On-site Meteorology – Continuous pre-and post operational monitoring is a required element (minimum of two years prior to licensing issuance)…data are used to assess potential radiological impacts due to routine and hypothetical accident release scenarios

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Meteorological Reqs for Licensing

• NRC requirements are much more extensive than EPA’s requirements for industrial facilitieso Basic requirements are in 10 CFR 52o Specific requirements are provided in numerous NRC

guidance documents NRC Regulatory Guide 1.23 Meteorological Monitoring

Programs for Nuclear Power Plants Many others

• NRC always requires on-site meteorological monitoring, whereas EPA rarely requires it

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Regulatory Drivers

• Primary Objective: To provide representative data suitable for use in dispersion modeling of radiological releases

• Schedule & Lead Time Considerations:o Tower & instrument procurement/installation (3 to 6 months, typ.)o Minimum 1-year of operational data prior to application submittalo Minimum 2-years of operational data prior to license issuance

• System Design – Siting Considerationso Must be representative of the siteo No undue influence from terrain, vegetation, thermal effectso Due consideration should be given to the influence of construction

and operation of the planto Systems typically designed for permanent operation (including plant

operation)o Complex terrain may require multiple towerso Basic criteria provided in RG 1.23

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Meteorological Monitoring Reqs

• System Design – Basic Componentso Minimum of two monitoring levels (10- and 60-meters is

recommended) for the following minimum parameters Wind Speed (10- and 60-m) Wind Direction (10- and 60-m) Ambient Temperature (10- and 60-m) Vertical Temperature Difference (for atmospheric stability) Dew Point (10-m) Precipitation (near ground level)

o Minimum data recovery objective: 90%o Electronic data logging devices must sample data in ≤ 5 second

intervals, and compile results in 15- and/or 60-min averageso QA/QC requirements are stringent

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Meteorological Monitoring Reqs (Cont’d)

• New Tower in Levy County, FLo Site of Progress Energy’s Proposed Levy Nuclear Plant

(two Westinghouse AP-1000 units are proposed)o 3400 acre forested site

Flat site Undeveloped (no structures or public roads onsite) Sandy conditions and high water table required deep footings Remote location required use of solar power and cellular phone

modem

o Tower and instrumentation designed and installed by Murray and Trettel of Palatine, IL

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Example of Recent Tower Installation

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Progress Energy Florida - Service Territory

Crystal River

Levy

12 200 ft. Tower and Surrounding Terrain

13 Tower Base and Security Fence

14 Solar Power System and Instrument Enclosure

15Lower Level Wind and Temperature Sensors

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Upper (60-m) and Lower (10-m) Level Sensors

17 Tower Guy Wire Anchor

• High data recovery targets require continuous oversight and scrutiny of operation

• Electronic Data Management Systems allow real time data access, flexibility of operation, and remote operationo Remote interrogation via land line or cellular modemo Frequent downloading of data minimizes data loss

due to system failureso Programmable system allows simple data conversiono Remote troubleshooting allows for consistency

checks and diagnosis of potential problems without field visits

Comparison of data with redundant system measurements Comparison of data with local or regional observations Search for trends and anomalies in data

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System Operation

• Data recovery can be increased by:o Daily interrogation and data scrutinyo Maintaining and calibrating instrumentation on a periodic basiso Install new/rebuilt/calibrated instruments at periodic intervalso Maintain spare equipment to avoid repair delays

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System Operation (Cont’d)

• Some parameters can be significantly affected by how they are averaged

• Example: Wind Speed can be stated as a VECTOR average or as a SCALAR average

o Neither is incorrecto Results can be very differento Users should be aware of intended use of data and implications

of how the data was processed

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Data Averaging Considerations

5 m/s

5 m/s

3.5 m/s

5 m/s5 m/s

5 m/s

5 m/s

Vector Average = 0 m/sScalar Average = 5 m/s

Vector Average = 3.5 m/sScalar Average = 5 m/s

Vector Average = 5 m/sScalar Average = 5 m/s

Case “A” Case “C”Case “B”

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Examples of Vector and Scalar Wind Averaging

• At low wind speeds, vector average wind speeds can be significantly understated

• Understated wind speeds will result in overstated dispersion modeling results (since Gaussian dispersion modeling results are inversely proportional to wind speed)

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Implications of Vector vs. Scalar Averaging

• Progress Energy conducted a year-long comparison of Vector and Scalar averages in North Carolina using co-located sensors

• A statistical regression analysis of the data indicated a distinct correlation:USCALAR = 1.03 × UVECTOR + 0.4 (4 months, r=0.99)

USCALAR = 1.00 × UVECTOR + 0.31 (18 months, r=0.92)

• Results should be site-specific

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Comparison of Vector vs. Scalar Averages

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Progress Energy Carolinas - Service Territory

Brunswick

Harris

Robinson

25 Co-located Wind Sensors

• Site-specific meteorological data is considered to be a critical component of nuclear plant siting and licensing, being used to support safety related analyses

• Given the importance of this data, due care and consideration are required in the planning, design, and operation of on-site monitoring systems in order to successfully meet regulatory criteria

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Summary