A camera for the measurement of pin bow in nuclear reactor fuel elements

Measurement of pin bow is part of the normal procedure in the optical examination of those CAGR nuclear fuel elements which are selected for post-irradiation examination. A device suitable for making measurements of pin bow swiftly and accurately, and if necessary for providing a permanent photographic record is described. An objective lens of physically large diameter relative to the pin size is employed. With the longitudinal axis of the 36 pin bundle aligned to the axis of the lens a real shadowgraph image can be obtained of any point along the length of a pin or array of pins. This image is referred to a standard template to measure bowing. (author)