Document: NRC Regulatory Guide
Document ID: 4d46a966-d280-43da-9b03-8b0abe7b29ce
Document Type: regulatory_guide
Title: Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2120/ML21204A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.183
CFR Part: 
CFR Title: 

Content:
our EAB χ/Q value, sum the doses for each pathway for each time increment, and then identify the maximum 2-hour EAB TEDE. As a conservative alternative, the maximum 2-hour TEDE for each path could be summed to determine the value for the accident. f. TEDE should be determined for the most limiting receptor at the outer boundary of the LPZ for the duration of the accident and should be used in determining compliance with the dose criteria in 10 CFR 50.67 and 10 CFR Part 52. For the first 8 hours, the breathing rate of persons off site should be assumed to be 3.5x10-4 m3/s. From 8 to 24 hours following the accident, the breathing rate should be assumed to be 1.8x10-4 m3/s. After that and until the end of the accident, the rate should be assumed to be 2.3x10-4 m3/s. 4.2 Control Room Dose Consequences The following guidance should be used in determining the TEDE dose for demonstrating compliance with 10 CFR 50.67(b)(2)(iii). For the purpose of this RG, a transit dose is considered to be the dose that is accumulated as personnel travel to and from the control room for the duration of an accident once onsite (e.g., dose from site boundary to the control room). Licensees whose licensing basis includes transit dose should include the transit dose to demonstrate compliance with 10 CFR 50.67(b)(2)(iii). The licensee’s results for the evaluation of transit dose will be evaluated on a case-by-case basis. New reactor 13 For the EAB TEDE, the maximum 2-hour value is the basis for screening and evaluation under 10 CFR 50.59. Changes to doses outside of the 2-hour window are considered only in the context of their impact on the maximum 2-hour EAB TEDE. DG-1389, Page 25 licensees that are required to show compliance with GDC 19 or similar control room radiological habitability principal design criteria may use this guidance. The following guidance should be used in determining the TEDE for persons located in the control room. 4.2.1 Sources of Radiation The TEDE analysis should