Doryokuro Kakunenryo Kaihatsu Jigyodan

Kobe Steel, Ltd.

Sumitomo Metal Industries, Inc.

Yuji Enokido

Masayuki Fujiwara

Hiroshi Teranishi

Susumu Hirano

Toshio Nishida

Shigeo Nomura

Itaru Shibahara

Takanari Okuda

Kuniaki Ara

Aturou Iseda

Hiroshi Hiroi

Motoharu Nakajima

The present invention provides a method for identifying failed fuel elements and the scale of damage accurately, quickly and at low cost without disassembling a fuel assembly and without discharging radioactive waste. Radiation detector(s) for measurement of gamma radiation emitted from surface of the irradiated fuel assembly and the fuel assembly are rotated and translated relative to each other, the dectected data of the radiation emitted from the surface of the fuel assembly is acquired, processed, a tomographic image is constructed from the radiation intensity distribution and is prepared and displayed, and a failed fuel element is finally confirmed from the tomographic image of the fuel assembly cross-section.

Method for detecting failure of nuclear reactor fuel

A dispersion strenghened ferritic steel having excellent ductility and toughness which has been heat treated to produce a matrix having a tempered martensitic structure composed of 0.05 to 0.25% by weight of carbon, 0.1% by weight or less of silicon , 0.1% by weight or less of manganese, 8 to 12% by weight of chromium, 0.1 to 4.0% by weight in total of molybdenum and tungsten, and 0.02% by weight or less of oxygen (exclusive of oxide particles) with the balance being iron and inevitable impurities and, homogeneously dispersed in the matrix, composite oxide particles comprising Y.sub.2 O.sub.3 and TiO.sub.2 in an amount of 0.1 to 1.0% by weight in total of Y.sub.2 O.sub.3 and TiO.sub.2 and a TiO.sub.2 to Y.sub.2 O.sub.3 molar ratio of 0.5 to 2.0.

Dispersion strengthened ferritic steel for high temperature structural

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Mito, Japan

Yuji Enokido