Performance Evaluation of Accident Tolerant Fuel Concepts for APR1400

  • Ali AlRaisi

    Student thesis: Master's Thesis


    A short-term station blackout (STSBO) was simulated to evaluate the responses of nuclear power plants (NPPs) with different ATF cladding materials using a modular accident analysis program (MAAP) code. Zion NPP was used as a pressurized water reactor (PWR) type plant model. First, during an STSBO the main event times such as the core uncover, core melting, and hot leg rupture were determined for the conventional UO2/Zircaloy fuel cladding system and two other ATF candidates (i.e. SiC and APMT). Also, the amount of hydrogen (H2) generated by the cladding oxidation with high temperature steam was calculated as a function of time. In the comparison among it was found that the times for the core uncovery and core melting were not affected by replacing Zircaloy by ATF candidate cladding materials. Only the time for hot leg rupture was delayed with SiC and APMT. The amount of H2 during the STSBO was significantly reduced with ATF cladding materials. Further sensitivity analysis were performed using selected properties to determine their effects during STSBO. Zircaloy properties were used as reference values. Each property was simulated independently of other properties to identify the key properties that would impact the coping time and hydrogen generation. The simulation results showed that none of the fuel cladding materials impacted the core uncovery nor did any of them affect the core melting. However, it was shown that among the examined cladding properties the enthalpy of cladding could delay the time for hot leg rupture by creep. The amount of hydrogen generated during the STSBO was dependent on the parabolic rate constant and enthalpy of cladding materials.
    Date of AwardDec 2020
    Original languageAmerican English


    • accident tolerant fuel; station blackout; modular accident analysis program (MAAP); core melting; hydrogen generation

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