Document: NRC Regulatory Guide
Document ID: d1045e85-64b0-4a83-8450-067a4fcd130f
Document Type: regulatory_guide
Title: Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants + HISTORY –HISTORY 04/2014 – Periodic Review of Revision 1 – Reviewed with issues for future consideration 02/1983 – Reissued 02/1983 to correct page 1.145-7 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740205.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.145
CFR Part: 
CFR Title: 

Content:
ing the NRC staff plans for using this regulatory guide. Except in those cases in which an applicant proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the method described herein will be used in the evaluation of the following: 1. For early site review applications. 2. For construction permit applications (including those incorporating or referencing a duplicate plant design and those submitted under the replicate plant option of the Commission's standardization program). 3. Operating license applications. For operating reactors, the licensee may use the method described in this guide or may continue to use the method previously contained or referenced in the FSAR for such facilities. This guide does not apply to the following options specified in the Commission's standardization policy under the reference system concept: 1. Preliminary design approval applications. 2. Final design approval, Type 1, applications. 3. Final design approval, Type 2, applications. 4. Manufacturing license applications. The implementation date for this guide is December 30, 1982. 1.145-6 l4 5 IiI' O = ZaEZ t_ _ e l _I JI I I II!- I_ XDA 40/ i_ _ _C 11| E2 B E1 2 S 03 2 104 2 -3 I E z Fiur 1. Laea ifso1wtotmadrad uligwk fecs y S on stbliy 5Rf ) U adiioa infonaton 0 c ) o 00 ~j2 <0 05L0 2 - - MODERATELY STNL £0' 4100 2 5 0 2 5 14 25 1 DISTANCE FROM SOURCE (M) Figure 1. Lateral diffusion without meander and building wake effects, ay, vs. down- wind distance from source for Pasquill's turbulence types (atmospheric stability) (Ref. 7). The sigma values presented above are for unrestricted flow over relatively flat, uniform terrain. They may require modification before application in situations in which rough terrain or restricted flow conditions (e.g., within the confines of a narrow valley) must be considered or in coastal and desert areas. (See Ref. 12 for additional infonnation.) For purposes of estimating a y during extremely