Use of a programmable desk calculator to achieve fast, accurate control rod calibration

From second European conference of TRIGA reactor users; Pavia, Italy (13 Sep 1972). In TRIGA Owners' Conference. In the development of a least squares calculator program for the rapid calibration of control rods at the NSCR at Texas A&M University it was necessary to verify that all rods, with the exception of the transient rod, could be accurately defined by a single analytical expression. Since the vertical flux distribution in the core region follows a cosine function, a cosine squared variation was tested. The differential rod worths for nine differert calibrations of the three shim-safeties and the regnlating rod were normalized to their maximum value and the location of the maximum value was shifted to the nominal control rod midpoint which is 20 cm. By trial and error a value of the argument for the cosine function was found. (auth)