Transcript ANSI/ANS-3.11-2005 American National Standard for Determining

ANSI/ANS-3.11-2005
American National Standard for
Determining Meteorological Information
at Nuclear Facilities
R. Brad Harvey, CCM
Physical Scientist
Office of Nuclear Reactor Regulation
U.S. Nuclear Regulatory Commission
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Presentation Topics
• History of U.S. NRC Meteorological
Monitoring Guidance
• ANS/ANSI 3.11-2005
• Potential Updates to U.S. NRC
Meteorological Monitoring Guidance
– 3rd Proposed Revision 1 to RG 1.23
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Safety Guide 23 (RG 1.23)
• Issued in Feb 1972
• Guidance Topics
– Parameters
• Minimum 2 levels of wind speed, wind direction, temp
• Dew point or humidity where there is an potential for
increased fogging/icing
– Siting
• Tower at same elevation as plant
• Avoid influence of nearby structures
• Measurements at
– 10m
– Vent release height
– Stack height (if applicable)
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Safety Guide 23 (RG 1.23)
• Guidance Topics (cont’d)
– Data recording
• Dual recorders (2 digital or 1 analog/1 digital)
– Instrument Accuracy
• Wind direction: ±5° (instantaneous values)
• Wind speed: ±5mph (time average)
• Temperature: ±0.5°C (time average)
• Delta-temperature: ±0.1°C (time average)
• Dew point: ±0.5°C (time average)
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Safety Guide 23 (RG 1.23)
• Guidance Topics (cont’d)
– Maintenance and Servicing
• 90% data recovery goal
• Semiannual calibrations
– Data reduction and compilation
• Data averaged over 15–60 min
• Compiled into annual Joint Frequency Distributions
• Stability based on delta-T or sigma-theta
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Safety Guide 23 (RG 1.23)
• Guidance Topics (cont’d)
– Special Considerations
• Additional monitoring in complex terrain
• Precipitation and Solar Radiation may be desirable
– Documentation
• Describe program in FSAR
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(1st) Proposed Rev. 1 to RG 1.23
• Issued in Sept 1980 (post-TMI)
• Additional Guidance
– Siting
• Avoiding structure influences
• Instrument boom length/orientation
• Aspirated temperature shields
• 10m & 60m measurement heights, higher for
stacks
• Additional monitoring for coastal & valley sites
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(1st) Proposed Rev. 1 to RG 1.23
• Additional Guidance (cont’d)
– Data Recording
• Sampling rates
• CR/TSC/EOF displays
– System Accuracy
– Data Reduction & Compilation
• Hourly averages
• Hourly database submittal
– Quality Assurance
• 10 CFR Part 50 Appendix B
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(1st) Proposed Rev. 1 to RG 1.23
• Additional Guidance (cont’d)
– Special Considerations for Emergency
Preparedness
• Independent 10m backup tower
• Remote interrogation
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ANSI/ANS-2.5-1984
• Approved in September 1984
• Many aspects in common with Proposed
Rev. 1 to RG 1.23
– Did not include “Special Considerations for
Emergency Preparedness”
• No references to 10m backup tower or remote
interrogation
• Reaffirmed in 1990; withdrawn in 2000
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2nd Proposed Rev. 1 to RG 1.23
• Issued in April 1986
• Endorsed ANSI/ANS-2.5-1984
– Took exception to ANSI/ANS-2.5-1984 QA
program guidance
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ANSI/ANS-3.11-2000
• Approved in February 2000
• Expanded Applicability to Nuclear Facilities in
•
Public Sector (e.g. National Labs)
Cooperative Effort
– NUMUG
– DMCC
• Moved ANS Subcommittees
– From: ANS-2 Site Evaluation
– To:
ANS-3 Reactor Operations
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ANSI/ANS-3.11-2000
• Guidance Topics
– Meteorological Measurements
– Siting of Meteorological Instrumentation
– Data Acquisition
– Data Base Management
– System Performance
– Appendixes (for information only)
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ANSI/ANS-3.11-2005
• Approved by ANS December 2005
– Awaiting approval by ANSI before publishing
• Updates/Enhancements
– System calibration methods
– System accuracy calculations
– Editorial and clarity changes
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ANSI/ANS-3.11-2005
• Meteorological Monitoring System
– Basic Meteorological Measurements
• Wind speed, wind direction, temp, precip
– Supplemental Meteorological Measurements
• Moisture, solar/net radiation, pressure, mixing height, etc.
– Remote Sensing Technologies
• Sodar, radar wind profilers, NEXRAD, satellite data, etc.
– Sources of Other Surface Observations
– Meteorological Observation Towers
– Stability Class Determination
• Delta-T, sigma theta, sigma phi, Monin-Obukhov length, etc.
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ANSI/ANS-3.11-2005
• Instrument Siting
– Topographic Effects
• Flat terrain, mountain, and shoreline sites
– Instrument Orientation
• Aerodynamic effects of obstacles, diabatic effects
– Optional Site Selection Techniques
• Remote sensing, tracer studies, numerical
modeling, physical modeling, etc.
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ANSI/ANS-3.11-2005
• Data Acquisition
– Recording Mechanisms
• Primary system: digital
• Optional backup system: analog or digital
– Sampling Frequencies
• Averaging: At least 30 samples at intervals no longer than 60
sec spaced over not less than 10 min period
• Standard Deviation: more frequent sampling
– Data Processing
• 10-15 min averages for display in CR/TSC/EOF
• Hourly averages for climatic and dispersion analyses
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ANSI/ANS-3.11-2005
• Data Base Management
– Representative Site Data Bases
• 3-5 yrs of onsite data for dispersion calculations
– Data Validation Techniques
• Compare to expected range of values, redundant
sensors, other tower levels, other data sources,
etc.
– Data Substitution
• From redundant sensors, other tower levels
(adjusted for change in height), linear interpolation
for short periods of missing data, etc.
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ANSI/ANS-3.11-2005
• Data Base Management (cont’d)
– Data Recovery Rates
• 90% annually, individual channels and composite
WS/WD/DT joint frequency distributions
– Data Archiving
• Retain raw data for 5 years, valid hourly data for
life of facility
– Data Reporting
• Annual joint frequency distributions
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ANSI/ANS-3.11-2005
• System Performance
– System Accuracy
• Wind Speed: ±0.2 m/s or 5% of observed;
• Wind Direction: ±5°
• Temperature: ±0.5°C
• Delta-T: ±0.1°C
• Dew Point: ±1.5°C
• Time ±5 min
• Etc.
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ANSI/ANS-3.11-2005
• System Performance (cont’d)
– System Calibrations
• Encompass entire channel (from sensor to display/recorder)
• Preoperational and 6-month intervals thereafter
• Document “as-found” and “as-left” results
• Field versus laboratory calibrations
– System Protection, Maintenance & Service
• Protect against electrical faults, severe environmental
conditions, etc.
– Quality Assurance and Documentation
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ANSI/ANS-3.11-2005
• Appendixes (for information only)
– Supplemental Measurements
– Tower Siting in Complex Terrain
– Stability Class Determination
– Optional Site Selection Techniques
– Wind Computations
– Calibration Practices
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3rd Proposed Rev. 1 to RG 1.23
• Part of ongoing overall effort to update
regulatory guidance to support expected
new reactor applications
• May include consideration of guidance
provided in ANSI/ANS-3.11-2005
– Tower and instrument siting criteria
– System accuracy
– Data processing, recording, and displays
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