To change moderator purity: ! COMPUTE DENSITY AND WGT% FOR COOLANT INFO: :: TMP: <> K PUR: <> ATM% CALC DENS WATER >>Dcool<< LIB: WIMSD4 FIL: IAEALB ISO: 3 <> <> <> CALC WGT% D2O >>wgt1Hc<< >>wgt2Dc<< >>wgtOXc<< ; [Add the following lines:] ! Void EVALUATE Dcool := Dcool 0.001 * ;