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Title: Improvements in the reactor core isolation cooling (RCIC) pump model

Abstract

As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC (Reactor Core Isolation Cooling) systems that was observed during the Fukushima accidents and to extend BWR RCIC and PWR AFW (Auxiliary Feed Water) operational range and flexibility, mechanistic models for the Terry turbine are being developed and tested with the RELAP-7 code to simulate the RCIC system. In the previous work, we developed a set of analytical models for the normal working conditions, as well as the two-phase off-design conditions, of the RCIC system, based on Sandia’s original work. An under-expanded jet model was developed to replace the CFD-based reduced-order model in the Sandia work to obtain the velocity and thermodynamic conditions of the turbine stator inlet. The models include both an adiabatic expansion process inside the nozzle and a free expansion process outside of the nozzle to ambient pressure. For the two-phase off-design conditions, two well-established choking models were used - the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model. The new twophase Terry turbine model used the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. The two-phase nozzle expansion model was also developed bymore » considering the vapor phase with a similar model for the single-phase case with the assumption that the liquid phase would slip along the wall with a much slower speed and will not contribute to the impulse on the rotor.« less

Authors:
 [1];  [1]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
Publication Date:
Research Org.:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1467421
Report Number(s):
INL/EXT-18-44739-Rev000
TRN: US1902738
DOE Contract Number:  
AC07-05ID14517
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS; RCIC SYSTEMS; TURBINES; BWR TYPE REACTORS; PWR TYPE REACTORS; CRITICAL PRESSURE; REACTOR CORES; FUKUSHIMA DAIICHI NUCLEAR POWER STATION; REACTOR ACCIDENTS; BWR RCIC; RELAP-7

Citation Formats

Hongbin, Zhang, and O'Brien, James. Improvements in the reactor core isolation cooling (RCIC) pump model. United States: N. p., 2018. Web. doi:10.2172/1467421.
Hongbin, Zhang, & O'Brien, James. Improvements in the reactor core isolation cooling (RCIC) pump model. United States. https://doi.org/10.2172/1467421
Hongbin, Zhang, and O'Brien, James. 2018. "Improvements in the reactor core isolation cooling (RCIC) pump model". United States. https://doi.org/10.2172/1467421. https://www.osti.gov/servlets/purl/1467421.
@article{osti_1467421,
title = {Improvements in the reactor core isolation cooling (RCIC) pump model},
author = {Hongbin, Zhang and O'Brien, James},
abstractNote = {As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC (Reactor Core Isolation Cooling) systems that was observed during the Fukushima accidents and to extend BWR RCIC and PWR AFW (Auxiliary Feed Water) operational range and flexibility, mechanistic models for the Terry turbine are being developed and tested with the RELAP-7 code to simulate the RCIC system. In the previous work, we developed a set of analytical models for the normal working conditions, as well as the two-phase off-design conditions, of the RCIC system, based on Sandia’s original work. An under-expanded jet model was developed to replace the CFD-based reduced-order model in the Sandia work to obtain the velocity and thermodynamic conditions of the turbine stator inlet. The models include both an adiabatic expansion process inside the nozzle and a free expansion process outside of the nozzle to ambient pressure. For the two-phase off-design conditions, two well-established choking models were used - the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model. The new twophase Terry turbine model used the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. The two-phase nozzle expansion model was also developed by considering the vapor phase with a similar model for the single-phase case with the assumption that the liquid phase would slip along the wall with a much slower speed and will not contribute to the impulse on the rotor.},
doi = {10.2172/1467421},
url = {https://www.osti.gov/biblio/1467421}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 01 00:00:00 EST 2018},
month = {Thu Feb 01 00:00:00 EST 2018}
}