Determination of boron carbide (B4C) density with autopicnometer and by metrology method

Ceramic density determination has been made for boron carbide (B4C) as material for the control rod of TRIGA Reactor using two methods, i.e. done autopicnometer and metrology method. B4C ceramic has the nuclear reactor is for the main composition of nuclear reactor control rod because B4C ceramic has great cross section for neutron absorption. One type of nuclear research reactor using B4C ceramic as the main composition of the control rod is TRIGAR Reactor 2000 in Bandung. The control rods for Bandung TRIGA Reactor has been produced by Division of Nuclear Fuel Fabrication, Center for Nuclear Fuel Technology, BATAN. B4C ceramic for TRIGA control rods must be characterized through quality control testing, including density measurement. The methods used to determine the density of B4C ceramic were the use of autopicnometer and metrology The purpose of this activity to determine which method that has higher degree of accuracy and lower bias. The principle of measurement with autopicnometer is based on ideal gas law PV = NRT, while the metrology method is based on measurement using calipers and weighing the tested material. The density is determined by comparing the weight of the sample volume. The results show that the value of B4C density using autopicnometer is (2.48121 ± 0.0003) g/cm³ with 0.05 % bias while the value obtained in measurement by metrology method is (2.4762 ± 0.0000) g/cm³ with a bias of 0.15 %. Difference in deviation/bias for both methods is quite small or not significant at 0.10 %. Thus metrology method is considered as the preferable option for testing of B4C ceramic density since the method is in a way more practical and more economical. The metrology method is preferable particularly when the sample form is uniform, while the use of autopicnometer is preferable if the sample form is more irregular. (author)