Document: NRC Regulatory Guide
Document ID: cde52d5a-adf9-49be-9d1f-59449dfca895
Document Type: regulatory_guide
Title: TRIAL - Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2123/ML21235A008.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.247
CFR Part: 
CFR Title: 

Content:
before the offsite populations either shelter or evacuate, or both, and the speed at which evacuation proceeds. The consideration of these factors is based on recognized site-specific sources such as site-specific emergency plans and site-specific evacuation time estimates. • Appropriate dose reduction factors associated with occupancy of structures or vehicles are developed and applied. RG 1.247, Page 48 • The impact of initiating events that may also affect protective actions (e.g., seismic events) is assessed. • The uncertainties related to the protective action analysis are identified and characterized. The objective of the dosimetry PRA analysis element is to identify the analyses needed to estimate doses to offsite populations arising from airborne and deposited radioisotopes. The characteristics and attributes needed to achieve the objectives of the dosimetry PRA analysis element are as follows: • Dosimetric quantities (e.g., total effective dose equivalent, equivalent organ doses) to be assessed are identified. • All relevant short- and long-term exposure pathways (i.e., cloudshine, groundshine, skin deposition, skin absorption, inhalation, ingestion, and resuspension of deposited materials) are identified and included as appropriate for the results of interest. • The age and gender characteristics of the offsite population are clearly identified. • The duration of exposure for both acute and chronic exposures is clearly identified. • Recognized sources of pathway-specific dose coefficients are used to estimate dose from the identified exposure pathways. Dose coefficients are consistent with the dosimetric quantity being assessed (e.g., the use of dose coefficients from Federal Guidance Reports 11 and 12 (Ref. 39 and Ref. 40) are used to for the computation of total effective dose equivalent (TEDE). • The uncertainties related to the dosimetry PRA analysis element are identified and characterized. The objective of the health effects