Document: NUREG-0800
Document ID: 9061fdf7-74fc-4c1f-8378-738cfa4a84cb
Document Type: srp
Title: through 2.4.7 and the controlling flood level is selected.  The controlling flood
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070240.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.3
CFR Part: 
CFR Title: 

Content:
certified design material (CDM) for the standard design, including the site parameters, interface criteria, and ITAAC.13 IV. EVALUATION FINDINGS For CP and early site permit reviews, the findings will consist of a statement indicating the 14 completeness of the identification of site flood characteristics and flood design bases in compliance with 10 CFR Part 100 and GDC 2. For OL reviews or a COL review that references an early site permit, the flood history will be updated if necessary, with special attention to any 15 new flood of record. Sample statements for CP reviews follow: The maximum flood known to have occurred on the A River was in 1796. The peak discharge at B City, Montana, was estimated to be 10,200 m /s (360,000 cubic feet per 3 second (cfs)). The applicant estimated that a comparable flood would produce water 16 surface elevation at the site of 116 feet 35.4 m (116 ft) MSL. The maximum flood 17 during the period since records were maintained (1883) at B City was 9,900 m /s 3 (350,000 cfs) and occurred on October 3, 1929. These floods occurred prior to 18 construction of several upstream dams. Flood flows are now regulated by C and D Reservoirs as well as by upstream hydropower plants. The applicant has estimated potential flooding from rainfall over the E River basin upstream from the site. The probable maximum flood (PMF), the upper level of flooding the staff considers to be reasonably possible, was estimated to produce a flow of 140,000 m /s (5,000,000 cfs) near the city of F. This estimate was made by using 165% of the 3 19 Corps of Engineers project design flood (PDF) estimate of 85,800 m /s (3,030,000 cfs) 3 20 at the same location, as modified by upstream flood control reservoirs. The 85,800-m /s 3 (3,030,000-cfs) project design flood flow is estimated to be partially diverted to the 21 leveed G and H floodways upstream of the site, with 42,500 m /s (1,500,000 cfs) 3 22 continuing downstream within the levee system past the plant site. The