Document: NUREG-0800
Document ID: 496b5bd8-c9a2-4cf6-a703-e41c51e155ec
Document Type: srp
Title: CHANNEL MIGRATION OR DIVERSION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1819/ML18190A201.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.9
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Content:
tions received during the previous decade. Changes were made to update the text with editorial and clarifying statements, including utilizing consistent terminology within this SRP section and planned updates within the other SRP 2.4 sections. A key change to this SRP section was to introduce and define and introduce a new engineering term “consequential flooding.” In reference to any consequential flooding estimate, the staff is now proposing that the staff will evaluate applications for the inclusion of inundation maps identifying the elevation of flood waters in relation to SSCs within the reactor powerblock including those SSCs important to safety. Depending on the reactor sites’ topography and geography, the powerblock, and the service water intake structure, and the designated ultimate heat sink may be at different elevations relative to each other. As a consequence, the staff is also proposing to evaluate applications for separate flooding levels corresponding to these two features’ locations as flood elevations may vary across the reactor site owing variable site natural topography and the presence of multiple as-built reactor structures. The staff is also proposing to evaluate applications for inclusion of an analysis estimating the duration of the flood inundation event as well as consideration of “associated effects” in any water surface elevation estimate. A definition of “associated effects” has been introduced in the SRP text. Additional changes have been introduced to the SRP text to better clarify the staff’s review responsibilities in relation to information prospective applicants are expected to submit. The phrases “safety-related structures, systems, and components (SSCs)” and “SSCs determined to be important to safety” have been replaced in this SRP section with the phase “SSCs important to safety” to better correspond to the regulatory language cited in General Design Criteria 2. The staff is also proposing to place