Authors: A. Z. Mesquita, R. R. Rodrigues

The Nuclear Technology Development Center (CDTN) is a research institute administered by the Brazilian Nuclear Energy Commission (CNEN) located in Belo Horizonte/Brazil). The CDTN is equipped with a Triga Mark I nuclear reactor with almost 60 years of operation. Most of its fuel elements are in the core since the first criticality, and corrosion may occur that threaten the integrity of fuel claddings. The reactor coolant must be treated and controlled in order to maintain its low electrical conductivity and pH close to neutrality, in order to minimize the corrosion of the reactor components, mainly the fuel elements. The objective of this work is to present the leak monitoring system developed for the verification of possible leaks in the Triga fuel elements based on the sipping test. A correlation was also developed to find the diameter of a hypothetical small cylindrical hole in the fuel cladding as a function of Cs-137 activity values to be measured.

A. Z. Mesquita^{1 |} R. R. Rodrigues²
1Pesquisador Titular, CDTN/Cnen, Belo Horizonte – Brasil.
2Tecnologista Senior, CDTN/Cnen, Belo Horizonte – Brasil.