Document: NUREG-0800
Document ID: 332f67ca-c2d9-4259-bbfb-485a47724ddc
Document Type: srp
Title: REGIONAL CLIMATOLOGY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600393.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.3.1
CFR Part: 
CFR Title: 

Content:
based on the weight of the 100-year snowpack at ground level plus the weight of the 48-hour PMWP at ground level for the month corresponding to the selected snowpack. Depending on the location of the site, the 48-hour PMWP may not necessarily be in the form of frozen precipitation. A CP, OL, or COL applicant may choose and justify an alternative method for defining the extreme winter precipitation load by demonstrating that the 48-hour PMWP could neither fall nor remain on the top of the snowpack and/or building roofs. The weight of the 100-year return period snowpack should be based on data recorded at nearby representative climatic stations (e.g., Reference 17) or obtained from appropriate standards with suitable corrections for local conditions (e.g., References 10, 11). For the purposes of determining the extreme winter precipitation load, the 48-hour PMWP is defined as the theoretically greatest depth of precipitation for a 48-hour period that is physically possible over a 25.9-square-kilometer (10-square-mile) area at a particular geographical location during those months with the historically highest snowpacks. The weight of the 48-hour PMWP should be determined in accordance with reports published by NOAA’s Hydrometeorological Design Studies Center (e.g., References 18–22). 7. Ambient temperature and humidity statistics should be derived from data recorded at nearby representative climatic stations (e.g., Reference 23) or obtained from appropriate standards with suitable corrections for local conditions (e.g., Reference 10). Reference 23 provides a method for estimating 100-year return period extreme temperature values as a function of annual extreme temperature values. 8. High air pollution potential information should be based on U.S. Environmental Protection Agency (EPA) studies (e.g., References 24, 25). 9. All other meteorological and air quality conditions identified by the applicant as climate site characteristics for ESP applications or used as