(a) Field of the Invention
The present invention relates to resistance heating tubes constituting a simulated nuclear fuel cluster in a heat transfer test facility of a nuclear reactor and method of making same.
(b) Description of the Prior Art
In recent times, the nuclear reactors utilizing nuclear energy have been constructed in various countries, and consequently the ratio of the nuclear energy occupying in the total energy supply amount has been rising. These nuclear reactors, when an accident is brought about, exert a serious influence caused by radioactive contamination. Therefore, adequate consideration has been paid for safe operations of the nuclear reactors as well as the technicians in charge have carelessly devoted themselves to development of a nuclear reactor that is more safe and efficient in respect of maintenance and management. As a link in the series of investigations, it is necessary to measure a critical heat flux accurately beforehand in the manner of heating an original-sized simulated nuclear fuel electrically for the purpose of confirming that the heat caused by nuclear fission of nuclear fuel to be loaded on the nuclear reactor core may be removed completely. Usually, the heat transfer tests to measure the critical heat flux have been conducted by forming the electric resistance heating tubes like the nuclear fuel rods and using the simulated nuclear fuel cluster comprising several electric resistance heating tubes tied up in a bundle. However, as the resistance heating tubes constituting the conventional simulated nuclear fuel cluster are formed so as to have a uniform thickness or formed without taking into consideration the actual power distribution state of nuclear fuel rods, the power distribution state thereof is widely different from the actual power distribution state, and it has been regarded as a defect in the heat transfer test for effectively measuring the removal of heat from fuel rods with cooling water.