ANS has recently published a new standard:
ANSI/ANS-2.21-2022, Criteria for Assessing Atmospheric Effects on the Ultimate Heat Sink (revision of ANSI/ANS-2.21-2012 [R2016]).
The standard is available for purchase from the ANS Store.
Scope: The 46-page standard establishes criteria for the use of meteorological and hydrological data by nuclear facilities to evaluate the atmospheric effects from meteorological parameters on the ultimate heat sink (UHS). These input parameters may include dry-bulb temperature, wet-bulb temperature, dewpoint, cloud cover, relative humidity, precipitation, wind speed, incoming shortwave solar radiation, incoming longwave radiation, surface water temperature, and atmospheric pressure.
Nuclear power plant operators, design professionals, nuclear facility owners, and nuclear vendors/consultants will benefit from an awareness of the inherent limitations of meteorological data collection, as well as potential data resources described in this revision. The appendices provide examples of applying deterministic and risk-informed, performance-based approaches to developing input data for UHS performance modeling; examples of adjusting data for representativeness and gap filling; and a listing of additional online resources for meteorological data that will evolve with advances in monitoring technology.