X光照相法测量高温气冷堆燃料微球包覆层厚度

Thickness measurement of coatings for HTGR coated fuel particles

高温气冷堆对燃料微球各包覆层的厚度有严格的要求。测量包覆层厚度常用的方法是Ｘ射线照相法，瓷相磨片法，光学颗粒尺寸分析仪法和Ｖ型槽法。本文描述了用Ｘ射线照相法测量包覆层厚度的测量过程。采用光栅技术，用９８Ｊ型精密测量投影仪对Ｘ光底片进行测量，用微机采集和处理数据。该测量方法的测量重现性好，对一选定的微球重复测量直径２０次，标准偏差１μｍ左右。该测量方法是无损检验，测量精度高，速度快，过程便于监督，适合于燃料微球生产过程中的在线测量。

The thickness of coatings for the HTGR(high temperature gas cooled reactor)coated fuel particles must meet design requirements. Generally, available methods for coating thickness measurement are X ray projection microradiography, ceramographic section method, optical particle size analyzer method and V slot method. This paper gives a process of X ray projection microradiography for coating thickness detemination. The 98J mode precision measurement projector is used for measurement of X ray plate by grating technique and a personal computer is used to collect and to process the data. The diameter of a microsphere has been measured for 20 times repeatedly. The results show that the measurement repeatability is very good and the standard deviation is about 1μm only. The method is a nondestructive and its precision and speed are higher, the supervision of measurement process is easy. This method can serve as routine quality control method for manufacture of coated fuel particles.