Japan Nuclear Cycle Development Institute

Japan Atomic Energy Agency

Hitoshi Hayashida

Kuniaki Ara

Masaru Hirabayashi

Hiroaki Ohira

Masahiko Ohtaka

Discriminating radioactive nuclides of a gamma ray source and nondestructively measuring an image concentration and spatial distribution of a gamma ray by radioactive nuclides. A visualizing apparatus having a containerincluding a gamma ray source; a gamma ray detectoraround the containerwhich detects gamma rays through a collimator; a gamma ray detection signal processing devicewhich processes a gamma ray detection signal measuring energy and counted value thereof; an energy discrimination processing devicewhich performs discrimination and intensity analysis of radioactive nuclides by performing spectrum analysis of gamma ray energy and intensity measured for each unit time or position; an imaging calculation processing devicewhich forms images of concentration and space distribution of the gamma ray source for each discriminated radioactive nuclide; and an image display devicewhich performs visual display based on a result of the calculation processing.

Visualizing apparatus using gamma ray source

An apparatus for non-destructively inspecting an arbitrary heat exchanger tube among a group of heat exchanger tubes. The apparatus includes a radiation detector inserted in a heat exchanger tube to be inspected, at least one radiation source inserted in a plurality of heat exchanger tubes surrounding the heat exchanger tube to be inspected, and a CT processing unit. A cross section of the heat exchanger tube to be inspected is imaged by the CT processing. Also, by setting at least one radiation source in an inner portion of the heat exchanger tube, on the inner side of a group of heat exchanger tubes or on the outer side of the group of heat exchanger tubes, and by setting at least one radiation detector carrying a collimator on the outer side of the group of heat exchanger tubes, a cross section of the group of heat exchanger tubes can be imaged by the CT processing.

Apparatus for inspecting a heat exchanger tube and group of heat exchanger tubes

An intermediate heat exchanger-incorporated type steam generator having an intermediate heat exchanger tube and a steam generating heat exchanger tube disposed separately in a vessel storing a secondary coolant therein. A pump mechanism is made of an electromagnetic pump mechanism formed by an electromagnetic driving coil provided on an outer circumference of the vessel and a magnetic core attached to an inner cylinder disposed in the vessel. At least one porous plate or slotted plate is preferably disposed between the intermediate heat exchanger tube and steam generating heat exchanger tube.

Intermediate heat exchanger-incorporated type steam generator

A heat exchanger having an intermediate heating medium is provided. A multiplicity of inner tubes are disposed in a shell of a heat exchanger . A low-temperature heating medium Y (water) flows in these inner tubes and a high-temperature heating medium X (liquid sodium) flows in the shell. These inner tubes are divided into a plurality of groups so that each group has a plurality of said inner tubes. The plural inner tubes constituting one group are disposed in one outer tube , and an intermediate heating medium Z chemically inactive with respect to both the high-temperature heating medium and the low-temperature heating medium and excellent in heat transferring performance is passed through each outer tube. The possibility that the high-temperature heating medium and the low-temperature heating medium contact each other can be reduced to an extremely low level. By providing leakage detectors capable of detecting with respect to each of the outer tubes the high-temperature heating medium or the low-temperature heating medium leaking out into the intermediate heating medium flowing out of the outer tubes, the damage to the inner tubes of each group can be detected and identified speedily.

Growing community of inventors

Higashiibaraki-gun, Japan

Hitoshi Hayashida