The Calculation accuracy analysis of the core design code for ATR (Advanced thermal reactor demonstration plant; Reactivity worths of SUS control rod, Boron in DO and Xenon

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The calculation accuracy evaluation of the SUS control rod reactivity worth, boron reactivity and Xenon reactivity were performed on the basis of DCA experimental data, "Fugen" start-up test data and "Fugen" operation data by using the WIMS-ATR code. The main results obtained are as follows. (1)As is shown in the results of the calculation accuracy evaluation of the channel power distribution for DCA Pu-U two-region core by the WIMS-ATR code, the RMS(Root Mean Square) of the calculation error of the channel power distribution is 4.8% and the relative error of the radial peaking factor is +2.1%. (2)As is shown in the results of the calculation accuracy evaluation of the SUS control rods worths by the WIMS-ATR code, the calculation error of the SUS control rod worth is -5,9%, and the value satisfy the design margin +2.0,-1.9 % (C/E-1). (3)As is shown in the results of the calculation accuracy evaluation of the boron (in the heavy water) reactivity based on "Fugen" start-up test data by the WIMS-ATR code / the LAYMON-2A code, the calculation error of the boron reactivity is-2.2%+7.9%, and the value satisfies the design margin of 10%. (4)As is shown in the results of the calculation accuracy evaluation of the Xenon reactivity based on "Fugen" operation data by the WIMS-ATR code/the LAYMON-2A code, the calculation error of the Xenon reactivity is-1.20%+14.7%, and the value satisfies the design margin 20%.