Abstract: The stored energy will be accumulated in the graphite structure materials of the Heavy Water Research Reactor under long-term neutron irradiation. To ensure the safe decommissioning and disposal of the graphite components in the Heavy Water Research Reactor, the stored energy of graphite in three different positions of the thermal column of the Heavy Water Research Reactor was measured by differential scanning calorimeter. The scanning temperature range is 10-550 ℃, and the heating rate is 10 ℃/min. The results show that in the integral temperature range of 80-500 ℃, the stored energy release of the three kinds of samples is 70.690, 42.167, 18.158 J/g, respectively. The peak temperature of the stored energy release rate curve is higher than 300 ℃, and the specific heat capacity of the non-irradiated graphite sample is much higher than that of the thermal column graphite sample, which indicates that the stored energy release of the graphite sample in this experiment will not cause the temperature rise itself. According to the empirical formula, the fast neutron flux of the three kinds of samples is 6.75×10¹⁶, 6.10×10¹⁴, 1.89×10⁷ cm^-2, respectively. The stored energy release fraction curve and stored energy release rate curve were obtained, and the stored energy release rate constant curves of 1# and 2# position samples have at least two release peaks, indicating that there are at least two kinetic processes in the stored energy release process.