Difference between revisions of "SMR startup simulation (outdated)"
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In order to test and demonstrate the time dependent calculation capabilities of the Kraken framework in a reasonably realistic context, a time dependent simulation was conducted of the initial rise to power of a small modular reactor (SMR) core. | In order to test and demonstrate the time dependent calculation capabilities of the Kraken framework in a reasonably realistic context, a time dependent simulation was conducted of the initial rise to power of a small modular reactor (SMR) core. | ||
− | The modelled SMR is the same 37 assembly Er-UO<sub>2</sub> core that has been previously used for the demonstration of the depletion capabilities of Kraken. | + | The modelled SMR is the same 37 assembly Er-UO<sub>2</sub> fuelled core that has been previously used for the demonstration of the depletion capabilities of Kraken. |
+ | |||
+ | The transient starts from critical hot zero power (HZP) conditions (actually from 1 % power level) with all control rod banks at approximately 38 % insertion. The boron concentration in the coolant corresponds to the critical boron at all rods out (ARO) hot full power (HFP) conditions. The control rods are withdrawn from the core in a stepwise manner over 38 hours to allow for the accumulation of xenon in the core. To reformulate the simulation setup: | ||
+ | |||
+ | *Evaluate (in a time-independent simulation) critical boron at hot full power all rods out conditions with convergence in | ||
+ | **Neutronics | ||
+ | **Thermal hydraulics | ||
+ | **Fuel temperature | ||
+ | **Xenon | ||
+ | *Using that critical boron, evaluate (in a time-independent simulation) critical control rod position at 1 % power level with convergence in | ||
+ | **Neutronics | ||
+ | **Thermal hydraulics | ||
+ | **Fuel temperature | ||
+ | **Xenon | ||
+ | *Save initial conditions from the 1 % power level time-independent calculation. | ||
+ | *Start a time dependent simulation from 1 % power level and slowly withdraw the control rods fully from the core. | ||
+ | |||
+ | If the time-independent and time-dependent calculation methodologies produce equivalent steady state solutions and have been correctly implemented, the simulation should (in the end) end up in the same state as the time-independent HFP ARO calculation. | ||
== Initial steady state == | == Initial steady state == | ||
== Time dependent simulation simulation == | == Time dependent simulation simulation == |
Revision as of 11:36, 30 August 2021
Overview
In order to test and demonstrate the time dependent calculation capabilities of the Kraken framework in a reasonably realistic context, a time dependent simulation was conducted of the initial rise to power of a small modular reactor (SMR) core.
The modelled SMR is the same 37 assembly Er-UO2 fuelled core that has been previously used for the demonstration of the depletion capabilities of Kraken.
The transient starts from critical hot zero power (HZP) conditions (actually from 1 % power level) with all control rod banks at approximately 38 % insertion. The boron concentration in the coolant corresponds to the critical boron at all rods out (ARO) hot full power (HFP) conditions. The control rods are withdrawn from the core in a stepwise manner over 38 hours to allow for the accumulation of xenon in the core. To reformulate the simulation setup:
- Evaluate (in a time-independent simulation) critical boron at hot full power all rods out conditions with convergence in
- Neutronics
- Thermal hydraulics
- Fuel temperature
- Xenon
- Using that critical boron, evaluate (in a time-independent simulation) critical control rod position at 1 % power level with convergence in
- Neutronics
- Thermal hydraulics
- Fuel temperature
- Xenon
- Save initial conditions from the 1 % power level time-independent calculation.
- Start a time dependent simulation from 1 % power level and slowly withdraw the control rods fully from the core.
If the time-independent and time-dependent calculation methodologies produce equivalent steady state solutions and have been correctly implemented, the simulation should (in the end) end up in the same state as the time-independent HFP ARO calculation.