How to select default value of radiobuttonlist after reload page

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C#

How to select default value of radiobuttonlist after reload page (when select other value except default value from radiobuttomlist and reload page then not automatically set default value of radiobuttonlist after page load in asp.net C#).
I already try this code
in page load section

radiobuttonlist .SelectedIndex = 0 ;
radiobuttonlist .SelectedValue = "1";
rblAutoCalculation.Items.FindByValue("ACP").Selected = true;
rblAutoCalculation.Items.FindByName("ACP").Selected = true;