Document: NUREG-1555
Document ID: d82f8007-705d-4b2b-b71e-c89f767b3572
Document Type: esrp
Title: METEOROLOGICAL MONITORING
Source: NUREG-1555
Source URL: https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1555/initial/
Revision Date: 2007-10
Chapter: 6
Section ID: 6.4
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Content:
n and wind speed at two levels, ambient air temperature difference between two levels, temperature, and atmospheric moisture at height(s) representative of water-vapor release (at sites at which large quantities of water vapor are emitted during plant operation). Guidance on meteorological data to be used as input to atmospheric dispersion modeling and assessment is given in Regulatory Guides 1.111 and 1.21. With these considerations in mind, the reviewer should evaluate instrument siting, meteorological sensors, and the recording of their output, instrument surveillance, data acquisition and reduction, and data screening. Instrument Siting The reviewer should compare instrument types, heights, and locations to the recommendations of Regulatory Guide 1.23, Sections C.1 and C.2, as follows: (Note: Additional guidance on instrument siting may be found in ANSI/ANS-2.5, “American National Standard for Determining Meteorological Information at Nuclear Power Sites,” and in International Atomic Energy Agency Safety Series No. 50-5G-S3, “Atmospheric Dispersion in Nuclear Power Plant Siting” [IAEA 1980].) (1) Evaluate local exposure of instruments, as follows: (a) Examine the local exposure of the wind and temperature sensors to ensure that the measurements will represent the general site area after plant construction. ` Determine whether the tower that supports the sensors will influence the wind or temperature measurements. ` Keep the following guidelines in mind: - Professional experience and studies have shown that wind sensors should be mounted on booms so that the sensors are at least one (and preferably two or more) tower widths NUREG-1555 6.4-6 October 1999 away from an open latticed tower and at least two stack or tower widths away from a stack or closed tower. - For temperature sensors, mounting booms need not be as long as those for wind direction sensors, but the sensors must be unaffected by thermal radiation from the tower itself. - No temperature