Wrapper tube

Austenitic steel materials for clad (CW 15-15 Ti) and wrapper tube (EM10) were qualified respectively for 115 dpa (clad) and 100 dpa (wrapper S-A) on the basis of post-irradiation examinations. 

In order to remove the hexagonal wrapper tube efficiently prior to fuel chopping, a disassembly system with CO2 laser has been developed and tested. A reference cutting scenario has been established through tests with dummy fuel assemblies. A prototype test equipment of geometrically safe continuous rotary dtssolover was fabricated and tested. 

The analytical results for unprotected loss of flow and unprotected transient overpower as design basis accidents are presented below beyond design basis accidents were not considered at this stage. However, risk of a core disruptive accident due to local blockage of the core is expected to be low since there are no wrapper tubes in the RAPID core. 

Destructive PIE of samples machined from BN-350 and BN-600 wrapper tubes demonstrated the following [7.29, 7.30] ... 

The AGT 5 is concerned with the thermal-hydraulics and mechanics of the core and core components. The contact forces between sub-assemblies distorted as a consequence of irradiation effects were investigated in the CHARDIS HI rig (Risley). The dynamic behaviour of core arrays during earthquakes was examined in the RAPSODBB test facility (Saclay). Flow patterns at the core outlet and between sub-assembly hexagonal wrapper tubes were simulated in the HIPPO test rig (Risley). 

Figure 5.2 shows a typical core fuel element (also called a fuel pin) and fuel assembly (also called a fuel subassembly). The core fuel element contains the core fuel, upper and lower axial blanket fuels, and a space called the fission gas plenum within a cladding tube. Then they are assembled as a fuel element bundle. The fuel assembly contains the fuel element bundle in a hexagonal assembly duct called a wrapper tube. 

The cladding and wrapper tubes are made of high-strength stainless steels that can endure the high-temperature and fast-neutron—irradiation conditions. 

This book will introduce the materials considered for the different structural components of the Generation IV systems, under high doses of irradiation such as fuel cladding, wrapper tubes, internal structures, lower doses such as pressure vessel, or no irradiation such as the power conversion systems. It will deal with the behavior in the different environments encountered, liquid metals, molten salts, supercritical water, and gas, as well as the behavior under mechanical stress and irradiation. Subsequently, the different classes of materials for in-core and out-of-core applications will be discussed. 

The maximum temperature of the wrapper tubes of the fuel assemblies does not exceed 700°C. 

Thick walled wrapper tube ZrH layer - Blanket fuel... 

Protmsion in wrapper tube Rounded comer of wrapper duct tube 680.2 30.2... 

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