抄録
A new fuel assembly design with tightened fuel rod has been proposed to achieve high conversion ratio about 1 on Boiling Water Reactor. The steady and transient critical power performance of the tight lattice rod bundle had not been known sufficiently in spite of important items for evaluating the possibility of BWR core with high conversion ratio. Therefore, the critical power measurement tests for tight lattice rod bundle have been performed under BWR steady and transient conditions. As that result, it was found that Arai CHF correlation had enough ability for predicting the steady-state critical power and transient dryout time for tight lattice BWR rod bundle.
