Active Neutron Multiplication Method for Fuel Lattices in Water

Autor: Makoto Ueda, Takeshi Seino, Kikuchi Shigeto, Kumanomido Hironori
Rok vydání: 1992
Předmět:
Zdroj: Nuclear Technology. 97:131-142
ISSN: 1943-7471
0029-5450
Popis: In this paper an active neutron multiplication method is studied in laboratory experiments aiming at establishing and improving nondestructive measurement methods for a spent light water reactor fuel bundle in water. The fuel rods used in the experiments consist of 1.0-cm-diam UO{sub 2} pellets enriched to 1 to 3 wt% {sup 235}U, clad in 1.18-cm-o.d. aluminum tubes. The rods are arranged in square arrays spaced to form a 1.52-cm lattice. The analysis is carried out by two- of three-dimensional, three-energy-group diffusion calculations. A simple empirical expression for the correlation between the neutron flux and the effective neutron multiplication factor k{sub eff} is proposed in which a constant term is added to the well-known formula for one-point subcritical flux. The new expression has been found to be applicable to high-precision measurements. Through an experimental study of the correlation between the neutron flux profile and the neutron source response to a detector and studies of the new correlation expression, an improved measurement system is presented that is suitable for more precise measurements of k{sub eff}.
Databáze: OpenAIRE