Meteorological Considerations in Preparing a COLA for a Nuclear Power

Plant Located at a Greenfield Site

Ping Wan Bechtel Power Corporation

The 12th Nuclear Utility Meteorological Data Users Group MeetingJune 2008

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Preparing A Combined License Application

Offsite Data Requirements

Representativeness of the offsite data source

Suitable for use to establish Meteorological Design Criteria for plant components

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Preparing A Combined License Application

Onsite Data Requirements

Representative of overall site meteorology

Adequate data length and recentness of the meteorological records

Valid, accurate and defendable

Representative of long-term conditions

Suitable for making dispersion estimates

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Regulatory Requirements and Guidance

Partial List

R.G. 1.23, Rev. 1, 1.97 Rev. 4

R.G. 1.111, 1.145, 1.194, 1.78

NUREG 0800, Rev. 3

NUREG 1555

NUREG 1.206

NUREG 0654, 0696, 0737, 0523

ANS / ANSI 3.11

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Representative of an Offsite Data Source

Depending on: Proximity to the site

Differences in topography

Terrain elevation

Land use

Closeness to large bodies of water

Methods of data collection

Techniques of data recording

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Design and Operating Meteorological Basis

Snow Load on Roofs of Safety-Related Structures Weight of 100-year return period snowpack, and

48-hour PMWP

Wind Loading on Plant Structures 100-year return period (straight-line) 3-second gust

wind speed

UHS Meteorological Conditions Maximum evaporation and drift loss of water, and

Minimum water cooling, and water freezing in the storage facility

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Design and Operating Meteorological Basis

Tornado Parameters for Pressure and Tornado Missile Loadings on SSC Important to Safety

Maximum translational and rotational speed, and Maximum pressure differential with the associated

time interval

Ambient Temperature and Humidity Statistics for Design Heat Loads

2% and 1% annual exceedance and 100-year Max. DB and Coincident WB,

2% and 1% annual exceedance and 100-year Max. WB (non-coincident), and

98% and 99% annual exceedance and 100-year minimum DB

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Length & Recentness of Records

For a COL Application

A two consecutive annual cycles (preferably 3 or more whole years), including the most recent 1-year period

Meteorological data in the form of joint frequency distribution of wind speed, wind direction by atmospheric stability class as described in R.G. 1.23

An electronic listing of all hourly averaged data

At least one annual cycle of onsite meteorological data at the time of docketing

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Onsite Meteorological Monitoring Program Pre-application Monitoring

– Data collection is used to prepare the COLA.

– Establish a baseline for impact assessing impacts.

Site Preparation and Construction Monitoring

– Control anticipated impacts

– Detect any unexpected impacts

Pre-operational Monitoring

– Establish a baseline to reflect the as-built environment for identifying and assessing impacts.

Operational Monitoring

– Establish a baseline for evaluation of impacts and support emergency preparedness planning.

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Meteorological Data Collection System

Meteorological tower and instrument siting

Meteorological parameters measured

Data acquisition and reduction

System accuracy

Instrument surveillance

Quality assurance and documentation

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Meteorological Tower and Instrument Siting

Base of the tower at approximately the same elevation as the finished plant grade of the new units

Location of tower upwind of the existing and new plant cooling system

Upper measurement level of the tower within the TIBL for coastal or lakeshore sites

Sensor location at least 10 obstruction heights away from such obstructions

Wind sensors located on mast away from tower structure influence

Ambient temperature and humidity sensors located away from existing and proposed moisture sources

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Typical TIBL Event

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Meteorological Parameters Measured

Wind speed and wind direction at 2 levels (at 10- and 60- meter, which generally coincides with the routine release level for LWRs), and at the stack release height (if applicable)

Delta-T between 10- and 60-meter, and 10- and the stack release height

Ambient temperature at 10 meters

Atmospheric moisture at 10 meters, and at the top of the cooling tower (if applicable)

Precipitation on the ground at or near the tower

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Adequate, Valid and Defendable Data

Depending on:

Redundant Data Collection system

Data Acquisition and Reduction

System Accuracy

Instrument Surveillance, and

Quality Assurance and Documentation

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Climatic Representative

Evidence should be provided to show how well the onsite met data represent long-term conditions at the proposed site.

The climatic representativeness of the onsite meteorological data can be checked by comparison with nearby stations with similar geographical locations and topographical settings that have reliable long-term meteorological data.

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Use of Meteorological DataData Application Onsite

Data Offsite Data

Meteorological Design Criteria of the Plant (e.g., structures, heat dissipation system, UHS, HVAC)

V

Comparison of onsite and offsite sources to determine the appropriateness of climatological data use for design considerations

V V

Atmospheric dispersion estimates (X/Q) of design-basis accidents for evaluation of site acceptability and the adequacy of engineered safety features of the plant

V

Atmospheric dispersion estimates (X/Q) of postulated accidental radiological and toxic airborne releases of effluents for control room habitability assessment

V

Atmospheric dispersion estimates (X/Q) of routine airborne releases of effluents for individual and population dose projections

V V

Evaluation of environmental risks from radiological consequences of a spectrum of accidents

V

Evaluation of non-radiological environmental impacts (e.g., visible plume, fogging, salt deposition)

V V

Emergency Preparedness and Response Plans including making near-real time X/Q predictions

V

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Control Room Habitability Assessment

Meteorological considerations used to evaluate the personnel exposures inside the control room due to accidental release of:

Hazardous Chemicals store onsite and at nearby offsite facilities transport on nearby highway, rail and/or waterway

Radiological Material During design-basis radiological accidents ( e.g., LOCA, Steam Line Break, Fuel Handling

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Site Acceptability and Safety Analysis

Due to a Design-basis Accident Radiological dose consequences of postulated

accidents meet prescribed dose limits at : Exclusion Area Boundary Low Population Zone

X/Q estimates at: EAB: 0-2 hours LPZ: 2-8 hours, 8-24 hours, 1-4 days and up to 30-day averaging periods

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Individual and Population Dose Projection

During Normal Operation

Radiological effluent release limits can be met for any individual located offsite.

X/Q estimates at: the site boundary, nearby resident, cow/goat and vegetable garden

population out to 50-mile radius of the plant

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Environmental Risk Evaluation

The potential dispersion of radioactive material from a spectrum of severe accidents

The radiological consequences of a spectrum of severe accidents

MELCOR Accident Consequence Code System, Version 2 (MACCS2)

a statistical stochastic diffusion model including removal of particulate radio-nuclides from the plume by wet deposition

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Non-Radiological Environmental Impacts

Heat Dissipation System Cooling tower, Cooling reservoir, cooling canal Visible plume, Fogging, Icing, Salt Deposition

Auxiliary Boiler, Standby Diesel Generator, Concrete-batch Plant, and Diesel-Driven Construction Equipment

Air emissions – SO2, NO2, PM10, PM2.5, CO Degradation of ambient air quality Visibility impacts on Class I Area

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Emergency Preparedness and Response

Real-time display of 15-minute averages of wind speed (WS), wind direction (WD) and atmospheric stability class (Delta-T)

Submitted WS/WD/Delta-T as input to the NRC’s ERDS

Making near-real-time atmospheric transport and diffusion estimates within the EPZ

Provision of alternative sources of meteorological data

The tower and its instrumentation capable of surviving monitoring, and displaying the meteorological conditions for execution of emergency action levels

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Conceptual View of Atmospheric Processes

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Atmospheric Dispersion

Where does the material released to the atmosphere go?

How rapidly does it dilute in getting there?

How rapidly and by what mechanisms is it removed from the atmosphere?

= Transport + Diffusion + Deposition

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What Models and Assumptions To Be Used?

Depending on: Release characteristics and amount

Distance from the release location to the receptor of interest

Nature of terrain within the modeling domain

Length of time needed to be modeled

Amount of available meteorological data

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Dispersion Modeling Guidance & ToolsSample List

Types of X/Q Estimates NRC Guidance Tools

Routine & Accidental Radiological Releases

R.G. 1.111

R.G. 1.145

XOQDOQ

PAVAN

Control Room Habitability Evaluation (for both chemical and radiological releases)

R.G. 1.194

NUREG/CR-6210

R.G. 1.78

NUREG-0570

NUREG/CR-1152

ARCON96

HABIT

Emergency Planning and Response (Near Real-time Predictions)

(* Modifications required – adding plume tracking capability)

R.G. 1.23

NUREG-0654

NUREG-0696, 0737

MACCS2

RASCAL, V2.2

NARAC

MESODIF-II*

CALPUFF*

Environmental Impacts of Cooling Tower Plume

No specific guidance EPRI Model - SACTI

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Summary

Criteria for a successful COL Application

A valid, accurate, representative and complete meteorological data base

Use most recent and readily available offsite meteorological and climatological data

Use up-to-date meteorological information and references

Close coordination and cooperation between the regulatory agency, other COLA preparers, and permit applicants