Nonlinear dynamic modeling and simulation of a passively cooled small modular reactor

Samet E. Arda, Keith Holbert

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


A nonlinear dynamic model for a passively cooled small modular reactor (SMR) is developed. The nuclear steam supply system (NSSS) model includes representations for reactor core, steam generator, pressurizer, hot leg riser and downcomers. The reactor core is modeled with the combination of: (1) neutronics, and (2) thermal-hydraulics. For the helical-coil once-through steam generator, a single tube depiction with time-varying boundaries and three regions, i.e., subcooled, boiling, and superheated, is adopted. The pressurizer model is developed based upon the conservation of fluid mass, volume, and energy. Hot leg riser and downcomers are treated as first-order lags. Finally, the NSSS model is incorporated with a turbine model which permits observing the mechanical power. The overall nonlinear system is simulated for typical perturbations, e.g., control rod withdrawal and increase in steam demand. A detailed analysis of the results show that the steady-state values for full power are in good agreement with design data and the model is capable of predicting the dynamics of the SMR.

Original languageEnglish (US)
Pages (from-to)116-131
Number of pages16
JournalProgress in Nuclear Energy
StatePublished - Aug 1 2016


  • Dynamic modeling
  • Integral type pressurized water reactor
  • Single-phase natural circulation
  • Small modular reactor

ASJC Scopus subject areas

  • Nuclear Energy and Engineering
  • Safety, Risk, Reliability and Quality
  • Energy Engineering and Power Technology
  • Waste Management and Disposal


Dive into the research topics of 'Nonlinear dynamic modeling and simulation of a passively cooled small modular reactor'. Together they form a unique fingerprint.

Cite this