Document: NRC Regulatory Guide
Document ID: c9ebcbb0-96c4-4d29-be51-5acae9cc858a
Document Type: regulatory_guide
Title: Estimating Aquatic Dispersion of Effluents from Accidental and Routine Reactor Releases for the Purpose of Implementing Appendix I (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740390.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.113
CFR Part: 
CFR Title: 

Content:
oximation in the tuning of a real-time model. In an oscillatory flow such as a hydroelectric or pump storage reservoir where there is no salinity intrusion region, the Taylor formula alone may be used as a first approximation: 1.113-23 I I I IuIISj . . . .1.111 B I I I liii. B U I U  10 x 04 !0 0N WE.S2Q ROTTERDAM I'- POTOMAC WES IS WES1 DELAWARE 3 HUDSON +WE 14-0 DELAWARE 2 WES 10 0 I I *II * £ * YEII* 1 I I 1111111 I I I Il I if I . . .. I I I I I I II a0 i I I I I I I I 00 *ESTUARY NUMBER ED FIGURE 5. CORRELATION OF DISPERSION PARAMETER TO DEGREE OF STRATIFICATION (FROM THATCHER, at &L, REF: 64) I41" 0.1 10 f L | | | | e • gee I I I i I *noI ill. D |I These approximations are suitable only for periodic oscillating flows and not neces sarily for unidirectional flows (as will be further explained in Section 4.d of this appendix). Tuning of the dispersion coefficient should be performed after the friction coefficients are adjusted to simulate the observed flows, since Equation (39) is a function of Manning's coefficient.1 (3) Two-Dimensional Models The best approximation for the dispersion coefficients in the two-dimensional estuary model appears to be the one adapted for the one-dimensional real-time model discussed above. For example, as a first approximation in the simulation of Jamaica Bay, which can be classified as a well-mixed two-dimensional estuary,.Leendertse (Ref. 29) used Elder's formula with an additional factor for the effect of wind-induced turbulence. As with the one-dimensional models, tuning is necessary to match prototype observations and should be performed after roughness factors in the hydraulic part of the model have been established. In the salinity intrusion regions of the estuary, initial estimates based on the method described in Thatcher and Harleman (Ref. 54) should be adequate. d. Applicability of Models Choice of one of the above models involves several factors. Although these models are classi fied as estuary models, they may be