Document: NUREG-0800
Document ID: a4ef36de-b662-41f6-9e66-96e4b7197298
Document Type: srp
Title: MASS AND ENERGY RELEASE ANALYSIS FOR POSTULATED
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0601/ML060150002.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.1.3
CFR Part: 
CFR Title: 

Content:
volume noding of the piping system are similar to those of an approved emergency core cooling system (ECCS) analysis. The computer programs that are currently acceptable include SATAN-V (Reference 1), CRAFT-2 (Reference 2), CE FLASH-4 (Reference 3), and RELAP4 (Reference 4), when a flow multiplier of 1.0 is used with the applicable choked flow correlation. An alternate approach, which is also acceptable, is to assume a constant blowdown profile using the initial conditions with an acceptable choked flow correlation. Rev. 2 - January 2006 6.2.1.3-4 b. Initial Blowdown Phase Containment Design Basis The initial mass of water in the reactor coolant system should be based on the reactor coolant system volume calculated for the temperature and pressure conditions assuming that the reactor has been operating | continuously at a power level at least 1.02 times the licensed power level | (to allow for instrumentation error). An assumed power level lower than | the level specified (but not less than the licensed power level) may be | used provided the proposed alternative value has been demonstrated to | account for uncertainties due to power level instrumentation error. | Mass release rates should be calculated using a model that has been demonstrated to be conservative by comparison to experimental data. Calculations of heat transfer from surfaces exposed to the primary coolant should be based on nucleate boiling heat transfer. For surfaces exposed to steam, heat transfer calculations should be based on forced convection. Calculations of heat transfer from the secondary coolant to the steam generator tubes for PWRs should be based on natural convection heat transfer for tube surfaces immersed in water and condensing heat transfer for the tube surfaces exposed to steam. c. PWR Core Reflood Phase (Cold Leg Breaks Only) Following initial blowdown, which includes the period from the accident | initiation (when the reactor is in a steady-state full power operation | condition)