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:
ent uptake and transport models become available, the NRC staff will rely on existing field studies and the staff's and consultants' experience to determine the level of conservatism or realism of the applicant's estimates. If the appTicant elects to take credit for removal of certain ions from the surface waters by the process of sediment uptake, verification using site-related field data will be necessary. C. REGULATORY POSITION 1. The transport and water use models described in Appendix A of this guide are acceptable to the NRC staff for use in calculating the potential annual average radiation doses to the public that may result from radioactive material in liquid effluents routinely released to sur face water bodies. No general models for transport in ground water are included, as such analy ses are considered to be site-specific. The models in Appendix A are also acceptable to the staff for analyzing the dispersion and dilution of accidental spills of radioactive material in liquids to surface water bodies. Standards for ground-water analysis, currently being prepared by the American Nuclear Society for publication by the American National Standards Institute, will be evaluated for acceptability by the NRC staff when completed. 2. Although specific models are cited in Appendix A of this guide, the citations are intended to provide guidance in the selection of model types rather than to specify models. Applicants may use models other than those described in Appendix A, but should justify fully the analytical techniques, assumptions, and level of conservatism of the model ultimately chosen. *Lines indicate substantive change from previous issuance. 1.113-2 3. The choice of a specific model, values of input parameters, and assumed future flow fields is the responsibility of the applicant. The NRC staff recognizes that the applicant may choose initially to use simplified models employing demonstrably conservative assumptions. The most conservative assumption would