RIA 1-4 Experiment Specification Document

The Reactivity Initiated Accident (RIA) test series is being performed in the Power Burst Facility (PBF) to provide data for verifying analytical codes capable of predicting light water reactor fuel performance during hypothetical control rod drop (or ejection) accidents. The most important aspect of an RIA or an RIA test is the magnitude of energy deposited into the fuel, therefore the primary purpose of the RIA test series is to better define the relationship between e.nergy deposition and fuel rod behavior. In particular, the RIA research objectives are to determine failure thresholds, modes, and consequences with respect to total energy deposition, irradiation history, and fuel design. The most severe RIA is the postulated Boiling Water Reactor (BWR) control rod drop during reactor startup, therefore all the RIA tests will be conducted at BWR startup coolant conditions. Test RIA 1-4 will consist of a 4 x·4 array of rods positioned in a coolant flow shroud. Fourteen of the rods are unirradiated BWR/6-type fuel rods and two are water-filled rods. Two water rods will be interior rods positioned along one diagonal. The primary objective of Test RIA 1-4 will be to obtain data on clustered fuel rod behavior during a rapid power transient simulating a BWR control rod drop. This document provides a basis for understanding the test plan for Test RIA 1-4. Past RIA test experience and a review of the PBF-RIA tests which are scheduled for completion prior to Test RIA 1-4 are summarized. The fuel rod, water rod, grid spacer, flow channel, and bundle support structure specifications are described. The instrumentation required for this test is discussed. The preliminary reactor operation and posttest operation requirements are presented