Manufacturing And Testing Of Load Self-balancing Type Nuclear Island Containment Vessel Spreader

Project of the load self-balancing type steel containment vessel(hereafter referred to as “CV”) spreader prototype development is one of the significant research and development tasks in the design technology of steel containment vessel.At present, the design of AP1000 nuclear power project is divided into four sections of steel containment vessel main body and CV top and bottom heads, total of six sections. The CV spreader adopts the hanging beam structure, and consists of distributor, wire ropes, star hanging beam and adjustable stays. Deficiencies of this kind of spreader are mainly: one is each wire rope cannot balance by itself. Therefore, measuring device must be arranged on each wire rope, and then tension of each wire rope may be equal through the adjustable stay during CV lifting. The other is the star hanging beam is too heavy and is close to the diameter of CV. Thus, inconvenience caused to the handling and installation of the spreader. Design of the load self-balancing type steel containment vessel spreader can solve these two deficiencies.Load self-balancing type CV spreader prototype is developed in order to verify the novation design of the spreader with the application of 1:1 prototype. Correctness of the CV spreader design is verified through the design calculations. Performance test plan and load test plan based on which test devices are designed and fabricated are established according to the design specification and service function of the spreader. 100 t loads are adopted for the performance test and 1.25 x rated load for load test.Manufacturing of the CV spreader prototype are mainly including QC of materials, welding control, fabrication of the drum and branch beam, impact flexibility test of drum and pulley frame etc. Feasibility and correctness of the whole fabrication technology are verified and performance, sized and other parameters of the prototype are shown to be in compliance with design drawings.Performance test and load test are carried out after the fabrication of CV spreader completed. Performance test includes balancing test, simulated COG deviation test and length deviation test of wire ropes. Meanwhile, levelness of the load, wire rope tension and stress on the distributor under each test condition are tested. Rated load for the load test is 830 t, and actual load for the test is designed to be 1100 t. 20%, 40%, 81% and 100% of 1100 t, i.e. 220 t, 440 t, 891 t and 1100 t are applied respectively.Performance and load test plan of the CV spreader are verified to be reasonable and effective through the performance test and load test. The development and acceptance of the load self-balancing type CV spreader prototype show that each parameter and performance of the spreader can satisfy the design specifications and drawings. Performance test shows that the spreader prototype can balance the load by itself and is capable of 1.25 x rated load, which is in compliance with design requirements.