United States Nuclear Regulatory Commission - Protecting People and the Environment

What's New in the 2018 Update

Changes to Web Site Content

Starting from the 2016 Update, the schedule for performing component and system study updates is every other year, while the loss of offsite power and initiating event updates are still done each year. As such, the 2017 Update includes only the studies for loss of offsite power and initiating event, which are based on the data through calendar year 2017. This update (i.e., the 2018 Update) includes the studies for loss of offsite power, initiating event, component, and system studies using data through calendary year 2018.

The parameters used in the SPAR models have been updated using data through calendar year 2015. This includes initiating event frequencies, component unreliabilities, component unavailabilities, common cause failure alpha factors, and loss of offsite power nonrecovery probabilities.

Historical Update Summaries

Page Last Reviewed/Updated Tuesday, December 8, 2020