| 内容記述 | This report presents the radioactive corrosion product (CP) measurement work conducted at JOYO, the experimental fast reactor of PNC at Oarai Engineering Center, during its 8th annual inspecion. The work mainly dealt with the (1) measurement of deposition density for most dominant CP nuclides namely, 54Mn and 60Co, at the inner surfaces of main primary sodium piping, (2)measurement of surface gamma dose rates along the above piping and associated components like intermediate heat exchanger (IHX), main sodium pump overflow (O/F) column etc. and (3) analysis of the measured results with the help of tables and graphs. Deposition densities were determined from the gamma spectrum conuts measured with pure Ge solid state derector (SSD) system and then multiplying them (counts) by experimentally determined conversion factors (muCi/cm2/CPS). Surface dose rates were measured with CaSO4 thermoluminescence dosimeters (TLD). Measurement results show that the major CP nuclides deposited around the primary cooling loops were 54Mn, 60Co and 58Co with 54Mn as the most dominant isotope. 54Mn deposiedpreferentially in the cold leg region while 60Co and 58Co did so in the hot leg region. Average value of the deposition density of 54Mn at the cold leg region (loopA and Bcombinad) was found to be 3.273muCi/cm2 while that of 60Co at the hot leg region was 0.294muCi/cm2. Surface gamma dose rate averaged over the entire lenrth of the piping of loop A and B was 0.963 mSv/h and was found to be increased at a rate of 0.245mSv/h/EFPY. Some efforts were also made to compare the measured results with the corresponding values calculated by PSYCHE, a computer code developed by the PNC for calculation and prediction of CP buildup and associated ga㎜a dose rate distribution around the piping and components in an LMFBR facility. Ratios of calculated and measured values, i.e., C/E, were found to be ...
著者所属: 日本原子力研究開発機構(JAEA) |
