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FRAPCON Statistical Package. FRAPCON/FRAPTRAN Users Group Meeting September 7, 2012 Paul Clifford Division of Safety Systems Office of Nuclear Reactor Regulation. Statistical Package.
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FRAPCON Statistical Package FRAPCON/FRAPTRAN Users Group Meeting September 7, 2012 Paul Clifford Division of Safety Systems Office of Nuclear Reactor Regulation
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.
Manufacturing Tolerances • Manufacturing tolerances may be defined as a variety of distributions including uniform and normal.
Modeling Uncertainties • FRAPCON calibration modeling uncertainties defined in NUREG/CR-7022, Volume 2.
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.
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
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
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
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.