You are trying to cast a NULL to a boolean.
Your code :
DataRow dr = dt.NewRow();
dt.Rows.Add(dr);
this means dr["Email_Requriment"] is DBNull.Value so set
dr["Email_Requriment"] = false;
before you do:
dt.Rows.Add(dr);
and like Praveen says:
dt.Columns.Add("Email_Requriment", typeof(bool));