Trtik Pavel, Zubler Robert, Gong Weijia, Grabherr Robin, Bertsch Johannes, Duarte Liliana I
Laboratory for Neutron Scattering and Imaging (LNS), Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
Laboratory for Nuclear Materials (LNM), Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
Rev Sci Instrum. 2020 May 1;91(5):056103. doi: 10.1063/1.5143226.
In this work, for the first time, high-resolution neutron imaging (true spatial resolution of 13 μm) is used for irradiated nuclear fuel cladding, applying an adapted procedure for transfer, handling, and measurements of highly radioactive samples in combination with the neutron microscope detector at Paul Scherrer Institut. A sample container referred to as an active box for high-resolution neutron imaging of highly active spent nuclear fuel cladding sections was developed. Sections of unirradiated and irradiated cladding of duplex type, having a liner, with hydrogen average concentrations of 420 wppm and 450 wppm were investigated using this device. The irradiated cladding originated from a fuel rod operated for five cycles in a Swiss pressurized water reactor. The irradiated cladding sample was measured inside the active box. Long circumferential hydride accumulations were revealed together with notable hydride precipitation at the liner-substrate interface. Measurements of the unirradiated cladding in air and inside the active box delivered consistent results, confirming the applicability of the developed device for high-resolution neutron imaging.
在这项工作中，首次将高分辨率中子成像（真实空间分辨率为13μm）用于辐照核燃料包壳，采用了一种适用于高放射性样品转移、处理和测量的程序，并结合保罗·谢尔研究所的中子显微镜探测器。开发了一种用于高活性乏核燃料包壳段高分辨率中子成像的样品容器，称为有源箱。使用该装置研究了具有衬里、氢平均浓度分别为420 wppm和450 wppm的双相型未辐照和辐照包壳的截面。辐照包壳来自在瑞士压水反应堆中运行了五个循环的燃料棒。在有源箱内对辐照包壳样品进行了测量。发现了长周向氢化物积聚以及衬里-基体界面处明显的氢化物沉淀。在空气中和有源箱内对未辐照包壳的测量给出了一致的结果，证实了所开发装置用于高分辨率中子成像的适用性。
