Document: NUREG-0800
Document ID: 47be7233-5326-4a7d-a9c5-f3b91d565a72
Document Type: srp
Title: MINIMUM CONTAINMENT PRESSURE ANALYSIS FOR EMERGENCY CORE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070492.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.1.5
CFR Part: 
CFR Title: 

Content:
properties that would be acceptable 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 conservative condensing heat transfer coefficients for heat transfer to the exposed passive heat sinks during the blowdown and post-blowdown phases of the loss-of-coolant accident should be used (see Figure 2): (1) During the blowdown phase, assume a linear increase in the condensing transfer coefficient from h = 8 Btu/hr-ft - F, at t = initial 2 0, to a peak value four times greater than the maximum calculated condensing heat transfer coefficient at the end of blowdown, using the Tagami correlation (Reference. 2) , 32 33 h =7.25(Q/Vt ) max p 0.62 6.2.1.5-9 DRAFT Rev. 3 - April 1996 where h = maximum heat transfer coefficient, max Btu/hr-ft - F 2 Q = primary coolant energy, Btu V = net free containment volume, ft3 t = time interval to end of blowdown, sec. P (2) During the long-term post-blowdown phase of the accident, characterized by low turbulence in the containment atmosphere, assume condensing heat transfer coefficients 1.2 times greater than those predicted by the Uchida data (Reference. 3) and given in 34 Table 3. (3) During the transition phase of the accident, between the end of blowdown and the long-term post-blowdown phase, a reasonably conservative exponential transition in the condensing heat transfer coefficient should be assumed (See Figure 2). The calculated condensing heat transfer coefficients based on the above method should be applied to all exposed passive heat sinks, both metal and concrete, and for both painted and unpainted surfaces. Heat transfer between adjoining materials in passive heat sinks should be based on the assumption of no resistance to heat flow at the material interfaces. An example of this is the containment liner to concrete interface. (4) Variations from the above guidelines may be found acceptable if the overall ECCS