Patent Number: 053612809
Section: summary

BACKGROUND OF THE INVENTION The present invention relates to a nuclear fuel identification code reader and a fuel assembly, and more particularly to a nuclear fuel identification reader and a fuel assembly which are suitable for identification of a fuel assembly in a fuel storage pool. In the past, the identification of a nuclear fuel identification number of a fuel assembly loaded a fuel storage pool has been effected by an operator by watching on a television monitor a video image taken by a marine TV camera. This is reported in Nuclear Technology, Vol. 72, March 1986, pp. 321-327. In the prior art method in which the video image of the TV camera is monitored through the TV monitor, there are some cases where it is not possible to identify the fuel identification number marked on the fuel assembly if clad (soft clad primarily consisting of Fe.sub.2 O.sub.3) is deposited on the fuel assembly. A solution to the above problem is disclosed in JP-A-57-53688, particulary FIG. 4 thereof. Eddy current sensors are inserted into recesses formed on a top surface of a handle of the fuel assembly to detect the fuel identification number. JP-A-60-207095 and JP-A-57-110994 disclose techniques to identify the fuel assembly by detecting a mark such as a groove formed at a top of the fuel assembly by ultrasonic wave. SUMMARY OF THE INVENTION It is an object of the present invention to provide a nuclear fuel identification code reader capable of identifying a nuclear fuel identification code marked on a fuel assembly in a short time and with a high accuracy. It is another object of the present invention to provide a nuclear fuel identification code reader capable of checking loss of a fuel assembly stored in a fuel storage pool. It is other object of the present invention to provide a nuclear fuel identification code reader capable of checking the presence of nuclear fuel in a stored fuel assembly. The first characteristic feature of the present invention resides in the provision of an optical sensor and an ultrasonic wave sensor for detecting the nuclear fuel identification code, means for identify the nuclear fuel identification code based on the information derived from the optical sensor, and means for identifying the nuclear fuel identification code based on the information derived from the ultrasonic wave sensor. In this arrangement, the nuclear fuel identification code can be identified in a short time. The second characteristic feature of the present invention resides in the provision of means for comparing a current recognition result for the nuclear fuel identification code with a past recognition result therefor. Thus, any loss of the stored fuel assembly can be checked. The third characteristic feature of the present invention resides in the provision of means for photographing a Chelencoff light generated in the fuel assembly and means for image processing an image signal of the Chelencoff light photographed by said photographing means. Thus, the presence of the nuclear fuel in the stored fuel assembly can be readily checked.