Source Investigation Of The Nuclear Decommissioning Site Hpge ¦Ã Spectrometer Calibration

The nuclear facilities for military business of our country in 1950 to 1970 will go into the stage of decommission, In order to make the decommission reasonable and beneficial, it request us to understand the Radioactive circumstance of the nuclear facilities, namely characteristic investigation at the beginning. which is the most important and is the most complicated, moreover, which can provide the basis for decommission method and budget estimation. Generally, the work of characteristic investigation has two ways: one is operation estimation method; the other is experiment method. The two ways apply together, with each other for add, with each other for verification. The method of traditional destructiveness sample in experiment is limit and shortage because of existing hard work and making two times pollution, owe to these, the paper adopt non-destructiveness y measurement analytical technique. This method can accurately and fast detect the measurement circumstance through obtaining calibration factor with Monte Carlo simulation method and with the HPGe instrument appropriately shielded. To make it possible, This paper verify the theories calculation value with three spot source (~152Eu, ~137Cs and ~60Co), and get the internal structure parameter of the HPGe Y instrument , the simulation value fit together in ± 8% with experiment value. At the same time, this paper also examined the function of shield, and carried on the theories calculation through MC simulation, The theories value fit together in ±29% with experiment value. In order to describe the circumstance of pipe polluted, We created three outward appearances source and two inside appearances source (the same distribute ~241AM,~137Cs and ~60Co) and carried on the theories calculation (MC simulation ) and experiment measurement under the condition of different piping thickness, the result fits together in ± 10%; In the same way . for examination the possibility of the technique of non-destructiveness measurement with HPGe Y instrument , this paper carried on the theories calculation (MC simulation)and experiment measurement with radioactive uniformity body source model in SHI JIA ZHUANG, the pail for radioactive water in radioactive chemistry study organization,standard radioactive sample ( 4> 7.5 X 5cm) and the body source with different distribution, the result and the experiment values are basic to fit together . At the same time, the result of estimation the indetermination degree to calculation values and experiment values was carried on. these results testify the method of in-situ non-destructiveness measurement in decommission nuclear facilities with HPGe Y instrument shielded. And this thesis have as follows characteristics: ? We can deduce the inner structure parameters of HPGe instrument through sample experiment method and MC simulation method, when the factory doesn't provide it. (2) the calibration factor of radioactive samples in different geometry and different distribution was acquired through making use of the general MC software MCNP4B and HPGe Y instrument shielded.