Document: NUREG-0800
Document ID: 90078267-41fd-4e45-bc4c-a21ef5ed6dfb
Document Type: srp
Title: Revision 3 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070740442.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6
CFR Part: 
CFR Title: 

Content:
e steam in the containment. The effect of the steam-water mixing should be considered in the containment pressure calculations. C. Containment Steam Mixing With Water from Ice Melt. The water from ice melting in an ice condenser containment provides an additional heat sink as the subcooled water mixes with the steam while draining from the ice condenser into the lower containment volume. The effect of the steam-water mixing should be considered in the containment pressure calculations. BTP 6-2-3 Revision 3 - March 2007 3. Passive Heat Sinks A. Identification. The passive heat sinks that should be included in the containment evaluation model should be established by identifying structures and components within the containment that could influence the pressure response. Structures and components that should be included are listed in Table 1. Data on passive heat sinks have been compiled from previous reviews and used as a basis for the simplified model outlined below. This model is acceptable for minimum containment pressure analyses for construction permit applications until a complete identification of available heat sinks can be made (i.e., at the operating license review). Where no detailed listing of heat sinks within the containment is provided, the following procedure may model the passive heat sinks within the containment: (i) Use the surface area and thickness of the primary containment steel shell or steel liner, anchors, and concrete, as appropriate. (ii) Estimate the exposed surface area of other steel heat sinks in accordance with Figure 1 and assume an average thickness of 9.53 mm (3/8 inch). (iii) Model the internal concrete structures as a slab with a thickness of 30.5 cm (one foot) and exposed surface of 15,000 m2 (160,000 ft2). Acceptable heat sink thermo-physical properties are shown in Table 2. Applicants should provide a detailed list of passive heat sinks with appropriate dimensions and properties. B. Heat Transfer Coefficients. The following