Experimental Assessment On Safety For Cross-linked High The Polyethene High Integrity Container

With the rapid development of the nuclear power industry, the safe disposal of nuclear wastes has become a global problem for the sustainable development of nuclear power industry. Nowadays, there are many kinds of package container for low-and-intermediate level radioactive solid wastes. Most of the package containers we used are the imported cross-linked high density polyethene(CL-HDPE) High Integrity Container(HIC) produced by ES Company(USA). Considering the long-term development, it is of important scientific and economic value that China design analyse and nationalize HIC.In view of the above background, this paper focuses on the test of the material and structural performance of cross-linked high density polyethene high integrity container for low-and-intermediate level radioactive solid wastes. The main work is as follows:1. The performance test of cross linked high density polyethene materialAccording to the Cross Linked High Density Polyethene High Integrity Container for Low-and-intermediate level radioactive solid wastes(An approval to draft), this study has made a lot of tests on ross linked high density polyethene such as physical property test, mechanical property test, thermal property test, flame retardancy test, anti-mildew capability test and creep test. The results indicate that the material density, environment stress cracking resistance, shore hardness, elastic modulus, flexural modulus, charpy notched impact strength, deflection temperature under load, brittleness temperature, melting temperature, vicat softening temperature, the level of horizontal firing and fungi-growth grade, pre irradiation tensile strength, tensile strength after low dose irradiation fully meet the requirements concerned. But the fracture tensile strain, ignition point, creep property and tensile strength after high dose irradiation need to be improved.2. The dropping test and piercing test of High Integrity ContainerFor the cross linked high density polyethene container, two dropping tests were made : 1.2- meter high, 45° inclined free fall and 4-meter high, vertically fall, both of which used high speed camera and non-contact full-strain measurement system are used to measure the strain during the dropping test. According to the results of the dropping test, there is no cracking between barrel-shaped and head cover and the solid in the HIC is not leaked out. Two piercing tests of 1.5-meter high and 5-meter high, used non-contact full-strain measurement system to measure the displacement during the piercing test. According to the results there is no damage to the containing.3. Life Prediction of High Integrity ContainerThis paper has recorded nine kinds of creep tests under different stress levels to get the time-strain curve. According to the creep curve, we can get time for rupture under different levels of stress. By making the linear fitting of the stress and fracture time through the least square method, we get the stress-creep rupture time curve. What's more, Extrapolation Algorithm is adopted to get the tensile stress the container which is 8.89 MPa after three hundred years of use.