1 frapcon statistical package frapcon/fraptran users group meeting september 7, 2012 paul clifford...
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1
FRAPCON Statistical Package
FRAPCON/FRAPTRAN Users Group Meeting
September 7, 2012
Paul CliffordDivision of Safety Systems
Office of Nuclear Reactor Regulation
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Statistical Package
• FRAPCON-3.4 designed to provide best-estimate predictions. NRC needed ability to perform independent fuel rod design calculations.
• FRAPCON statistical package performs the following tasks:– randomly samples among specified distributions of manufacturing
tolerances, modeling uncertainties, and rod power uncertainties,– creates multiple FRAPCON input decks,– executes each of these unique cases, and – compiles the results (e.g., plots, 95/95 UTL, data files).
• Statistical package also allows introduction of a power ramp to existing rod power history.– User specifies ramp magnitude (KW/ft), time duration, and burnup
time step.
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Statistical Package (cont.)
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Manufacturing Tolerances
• Manufacturing tolerances may be defined as a variety of distributions including uniform and normal.
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Modeling Uncertainties
• FRAPCON calibration modeling uncertainties defined in NUREG/CR-7022, Volume 2.
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Usage
• NRC using FRAPCON statistical package to perform independent fuel rod design calculations.– End-of-life rod internal pressure.– LOCA initialization (stored energy).– AOO overpower cladding strain.– AOO overpower fuel power-to-melt.
• FRAPCON confirmatory calculations may support review of a variety of licensing applications.– New fuel rod designs.– Fuel vendor transitions.– Power uprates.– Condition reporting (e.g., fuel thermal conductivity degradation).– Review of new fuel performance models/methods.
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PWR 16x16 – UO2 Rod 1
Calculated end-of-life rod internal pressure (500 cases):
Nominal = 1676 psia
95/95 with sampled TOL = 1847 psia
95/95 with sampled TOL + FGR = 1873 psia
95/95 with sampled TOL + FGR + POW = 2015 psia
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20 25 30 35 40 45 50
Rod
Ave
rage
Pow
er (K
W/ft
)
Rod Average Burnup (GWd/MTU)
Limiting 2nd Cycle
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PWR 16x16 – UO2 Rod 2
Calculated end-of-life rod internal pressure (500 cases):
Nominal = 1809 psia
95/95 with sampled TOL = 1977 psia
95/95 with sampled TOL + FGR = 2088 psia
95/95 with sampled TOL + FGR + POW = 2332 psia
0
1
2
3
4
5
6
7
8
9
0 10 20 30 40 50 60
Rod
Ave
rage
Pow
er (K
W/ft
)
Rod Average Burnup (GWd/MTU)
Limiting 3rd Cycle
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PWR 14x14 – UGdO2 Rod
Calculated end-of-life rod internal pressure (500 cases):
Nominal = 1319 psia
95/95 with sampled TOL = 1463 psia
95/95 with sampled TOL + FGR = 1785 psia
95/95 with sampled TOL + FGR + POW = 1820 psia
0
1
2
3
4
5
6
7
8
9
0 200 400 600 800 1000 1200
Ro
d A
vera
ge
Po
wer
EFPD
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Conclusions
• FRAPCON statistical package provides a robust tool for performing independent fuel rod design calculations.
• During the past 12 months, NRC has completed confirmatory calculations to support the following licensing actions:– Calvert Cliffs Units 1 &2 fuel transition (CE 14x14).– Turkey Point Units 3 & 4 extended power uprate (W 15x15).– St. Lucie Unit 1 extended power uprate (CE 14x14).– St. Lucie Unit 2 extended power uprate (CE 16x16).
• NRC will continue to utilize statistical package to support licensing actions.