14. PLUTO2: Non-Voided Channel Fuel Motion Analysis

• 14.1. Introduction and Overview
  • 14.1.1. Historical Background and Description of the Physical Model
  • 14.1.2. Overview of the Program Flow
  • 14.1.3. Interaction with other SAS4A Modules
• 14.2. In‑Pin Fuel Motion
  • 14.2.1. Overview and Assumptions
  • 14.2.2. Initial Conditions for the In‑pin Calculation from DEFORM and the Pre‑Failure Pin Heat‑transfer Calculation
  • 14.2.3. Coupling of the In‑pin Motion Calculation with the PLHTR Heat Transfer Calculation
  • 14.2.4. Overview of the Numerical Approach for the In‑pin Fuel Motion Calculation and Description of Subroutines PLlPIN and PL2PIN
  • 14.2.5. Definition of the Generalized Smear Densities for the In‑pin Calculation
  • 14.2.6. Differential Equations for the In-pin Fuel Motion and Description of Sink and Source Terms
  • 14.2.7. Finite Difference Equations for the In-pin Motion
  • 14.2.8. Time-step Determination for the In-Pin Motion
• 14.3. Fuel and Fission-gas Ejection from the Pins
  • 14.3.1. Physical Model and Assumptions
  • 14.3.2. Numerical Solution of the Fuel and Gas Ejection Calculation
  • 14.3.3. Axial Pin Failure Propagation
  • 14.3.4. Complete Pin Disruption and Switch to LEVITATE
• 14.4. Channel Hydrodynamics Model
  • 14.4.1. Overview and Definition of Generalized Smear Densities
  • 14.4.2. Mass Conservation for Fuel, Sodium, and Free and Dissolved Fission-gas
  • 14.4.3. Fuel Flow Regimes, Fuel Plateout and Frozen Crust Release, Plated‑out and Moving Fuel Configurations, and Energy and Momentum Exchange Terms
  • 14.4.4. Mobile Fuel and Fuel Crust Energy Equations
  • 14.4.5. Sodium/Fission-gas Energy Equation and Channel Pressure Calculation
  • 14.4.6. Momentum Equations in the Coolant Channel
• 14.5. Temperature Calculation of Cladding, Structure, Reflector and Liquid Sodium Slugs
  • 14.5.1. Liquid Sodium, Cladding, structure, and Reflector Temperature Calculation Outside of the Interaction Region
  • 14.5.2. Cladding and Reflector Temperature Calculation in the Interaction Region
  • 14.5.3. Structure Temperature Calculation in the Interaction Region
• 14.6. Interaction with the Point Kinetics and the Primary Loop Module
  • 14.6.1. Interaction With the Point Kinetics Module
  • 14.6.2. Coupling with the Primary Loop Module
• 14.7. Code Logic Description
  • 14.7.1. PLUTO2 Initialization
  • 14.7.2. Time Step Considerations and Auxiliary Subroutines
• 14.8. Description of Input to and Output of the PLUTO2 Module
  • 14.8.1. PLUTO2 Input
  • 14.8.2. PLUTO2 Output
• 14.9. References
• 14.10. Nomenclature