Measurement and analysis of heat load in CN hole of HANARO

Cold neutron source facility is going to be built up in its 30 MW reactor HANARO in order to provide its scientific community a full range of neutron experimental devices. The liquid hydrogen cold neutron moderator currently under development will be positioned inside a vertical hole with 16 cm in diameter at the heavy water reflector of the reactor. In the design of cold neutron source (CNS), it is very important to measure the heat load experimentally for sizing of heat removal system and selection of the refrigerator, etc. Analysis of heat release data from gamma-rays shown that the experimental results are underestimated. The cause of underestimation can be explained by two cases. One is the different circumstance that the measurement was executed in CNS channel filled with light water, but the calculation was carried out in the vacuum channel. And the other is the fact that the calibration of IC-Gray was executed in the different range from that of real measurement. Therefore the measurement by IC-Gray was used only for calibration of the calculation code, and the calculation data by MCNP will be used as a ground data of design. (author). 4 refs., 15 tabs., 33 figs