AFT Fathom Used to Enhance 40-Year Old Hand Calculations at Nuclear Power Plant
AFT Fathom™ Case Study
Energy Northwest Columbia Generating Station | Fuel Pool Cooling System | Nuclear Power
“One great, but often unnoticed feature of AFT Fathom is model
size allowance. This model is rather large, and AFT Fathom could have
easily handled more. It is beneficial to have large Workspaces.”
– Ryan Walker, Senior Engineer
PROBLEM
- Existing nuclear cooling system was modeled with hand calculations
- Nuclear regulations required AFT software be verified against existing hand calculations
ANALYSIS
- AFT Fathom was used to model the cooling system under 9 operating conditions
SOLUTION
- AFT Fathom was confirmed with frictional loss differences ranging from 0.03% to 0.80%
- AFT Fathom is now the main modeling tool used at the power plant
Ready to try AFT Fathom?
Problem Explained
Energy Northwest used AFT Fathom to model a Fuel Pool Cooling (FPC) system at their Columbia Generating Station, a nuclear power plant they own and operate. The FPC system removes decay heat from pools of stored spent fuel and maintains the fuel pool’s specified temperature, purity, clarity, and level. This model was built to enhance the original, hand performed, 40-year-old calculation and to have it electronically available and easily editable.
Ryan Walker, Senior Engineer at Energy Northwest, explains, “Since our version* of AFT Fathom is not safety-related certified… we have to baseline against existing data to verify that the model is accurate. This is our company policy.”
Tools & Analysis
The AFT Fathom model used for this case study was extensively baselined against the existing analysis with very good accuracy, ranging from 0.03% to 0.8% difference in results with an average of 0.28% difference between the hand calculation and the AFT Fathom analysis.
Walker also made good use of the Scenario Manager feature. It allowed him to model the following six operational configurations that show different suction modes where the suction source varies along with different pump configurations (see the full case study for all 6 modes).
Solutions & Benefits
According to Walker, the main benefit of using AFT Fathom is versatility in making future modifications to the fuel pool cooling system and to quickly expand the analysis scope beyond the current basic analysis. Another advantage is the ability to produce multiple models using the Scenario Manager.
AFT Fathom model of the Fuel Pool Cooling (FPC) system at Columbia Generating Station, Washington.
Friction loss results comparing AFT Fathom to 40-year-old hand calculations