NONDESTRUCTIVE INSPECTION DEVICE AND NONDESTRUCTIVE INSPECTION METHOD FOR SYNTHETIC SLAB

To detect even a small defect in a synthetic slab, using a neutron beam.SOLUTION: A nondestructive inspection device 10 for a synthetic slab comprises: a neutron irradiation device 2 that irradiates a local irradiation location on a surface 1e of a synthetic slab 1 with a neutron beam; a detection device 3 that detects scattered neutrons returned from the synthetic slab 1 as a result of irradiating the irradiation location with the neutron beam at each detection position facing the surface 1e, and measures the number of detected scattered neutrons at each detection position; and a ratio calculation unit 5 that calculates, for each detection position, a ratio of the number of detected neutrons at the detection position to a reference value of the detection position. The reference value is set for each detection position as the number of detected neutrons when it is assumed that the synthetic slab 1 has no defects.SELECTED DRAWING: Figure 1A 【課題】中性子ビームを用いて、合成床版における小さい欠陥でも検出できるようにする。【解決手段】合成床版の非破壊検査装置１０は、合成床版１の表面１ｅにおける局所的な照射箇所に中性子ビームを照射する中性子照射装置２と、照射箇所への中性子ビームの照射の結果、合成床版１から戻って来た散乱中性子を、表面１ｅに対向する各検出位置で検出し、検出位置毎に散乱中性子の検出数を計測する検出装置３と、各検出位置について、当該検出位置の基準値に対する当該検出位置の検出数の比率を求める比率算出部５とを備える。基準値は、合成床版１に欠陥が存在しないと仮定した場合の検出数として検出位置毎に設定されている。【選択図】図１Ａ