Document: NUREG-0800
Document ID: 4571c66e-adba-49aa-a312-7e182788bd0d
Document Type: srp
Title: TECHNICAL SPECIFICATIONS AND EMERGENCY OPERATION REQUIREMENTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730455.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.14
CFR Part: 
CFR Title: 

Content:
s that may require emergency actions. Low-water events resulting from loss of storage due to dam-failures are reviewed in SAR Section 2.4.4; those due to surges and seiches are reviewed in SAR Section 2.4.5; those due to tsunamis are reviewed in SAR Section 2.4.6; those due to ice are reviewed in SAR Section 2.4.7; those due to channel diversions are reviewed in SAR Section 2.4.9; and those due to droughts are reviewed in SAR Section 2.4.11. The staff reviews these low-water events to identify the controlling low-water event and any emergency action that may be needed for safe operation of the plant during this event. As described by Regulatory Guide 1.59, SSC important to safety may be “hardened,” that is, SSC may have protection built into their structural design bases which provides a passive, “always-in-place” protection measure. Regulatory Guide 1.59 also allows for SSC not to have hardened protection if certain criteria regarding alternative protection are met. The staff should ask the organization responsible for review of the SSC to review hardened protection provided for SSC important to safety. Alternative protection measures that are non-permanent measures (i.e., are not always inplace) should be reviewed to ensure that these measures can be implemented. 2. Available Response Time: The staff analyzes the controlling hydrological events for which emergency action (e.g., sandbagging, shutdown, installation of flood gates and stop logs, etc.) is needed for the plant to determine the time available for initiation and completion of these emergency actions. The controlling hydrological events, including flooding and low-water events, are analyzed to determine the warning time available for emergency actions before onset of conditions that may preclude these actions. The environmental conditions likely to prevail during all potential flooding and low-water events, up to and including events of the severity of the controlling event, are reviewed to