Document: NRC Regulatory Guide
Document ID: 01fb3132-b05a-41a0-ab81-466a6fb6f4d3
Document Type: regulatory_guide
Title: Preparation of Environmental Reports for Nuclear Power Plant License Renewal Applications (Rev. 1)
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0916/ML091620409.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.2S1
CFR Part: 
CFR Title: 

Content:
use of impingement and entrainment. Provide full documentation of analytical or modeling techniques used to assess entrainment and impingement losses. Describe these losses in terms of the commercial, recreational, and ecosystem services they would have provided. If aquatic resources have been monitored in the field, provide an analysis of temporal and geographical trends in the data that might indicate whether fish and shellfish populations have increased, decreased, or remained stable during the initial period of operation. Show any relationships between patterns of impingement and entrainment at the plant and trends in the potentially affected populations. Because entrainment, impingement, and thermal impacts all affect field populations simultaneously, provide a single discussion of the effects of these stressors on trends in field data rather than discussing these three stressors individually, if possible. Thermal Impacts on Aquatic Organisms (Plants with Once-Through Cooling or Cooling Ponds) This section applies to plants with once-through and cooling pond heat dissipation systems. Table B-1 notes the following: Most of the effects associated with thermal discharges are localized and are not expected to affect overall stability of populations or resources. The magnitude of impacts, however, would depend on site-specific thermal plume characteristics and the nature of aquatic resources in the area. Specifically, 10 CFR 51.53(c)(3)(ii)(B) requires, in part, the following: If the applicant’s plant utilizes once-through cooling or cooling pond heat dissipation systems, the applicant shall provide a copy of current Clean Water Act 316(b) determinations and, if necessary, a 316(a) variance in accordance with 40 CFR Part 125, or equivalent State permits and supporting documentation. If the applicant can not provide these documents, it shall assess the impact of the proposed action on fish and shellfish resources resulting from heat shock…. Section 4.6.1.2 of the