Hot Cell Installation and Demonstration of the Severe Accident Test Station

Abstract

A Severe Accident Test Station (SATS) capable of examining the oxidation kinetics and accident response of irradiated fuel and cladding materials for design basis accident (DBA) and beyond design basis accident (BDBA) scenarios has been successfully installed and demonstrated in the Irradiated Fuels Examination Laboratory, a hot cell facility at Oak Ridge National Laboratory. Two test station modules provide various temperature profiles, steam, and the thermal shock conditions necessary for integral lossof-coolant accident (LOCA) testing, defueled oxidation quench testing, and high-temperature BDBA testing. Installation of the SATS system restores the domestic capability to examine postulated and extended LOCA conditions on spent fuel and cladding and provides a platform for evaluating advanced fuel and accident-tolerant fuel cladding concepts.This document reports on the successful in-cell demonstration testing of unirradiated Zircaloy-4. It also describes the integral test facility's capabilities, installation activities, and out-of-cell verification testing to calibrate and optimize the system.

In-cell Re-fabrication and Loss-of-coolant Accident (LOCA) Testing of High Burnup Commercial Spent Fuel

“…During the development and benchmarking of the in-cell Severe Accident Test Station, numerous out-ofcell LOCA tests were conducted with unirradiated 17x17 Zircaloy-4, which was filled with zirconia pellets to simulate the heat capacity of the fuel. After the SATS was installed in the main hot cell in 2017, a full sequence in-cell LOCA test was conducted with the unirradiated Zry-4, the results of which were reported in a previous year's report [9]. The work presented in this report expands the demonstration of SATS to include testing on irradiated fuel.…”

“…The capabilities of the test rig include exposing a fuel rod segment to conditions typical of DBA and BDBA scenarios. The specifics of the SATS design have been extensively covered in previous ORNL reports [8,9]. The test rig consists of two modules: one for integral testing of LOCA scenarios and one module with a high temperature furnace for testing of fuel segments subjected to BDBA scenarios ( Figure 1).…”

Postirradiation Examination of the ATF-1 Experiments - 2018 Status

“…Baseline PIE has been completed and reported previously for five capsules [20,21]. In addition, baseline NDEs were completed on ATF-18, which has been shipped this year for safety testing in the Severe Accident Test Station (SATS) at ORNL [22]. PIE on the four other capsules received in April 2018, namely ATF-06, ATF-08, ATF-45 and ATF-73, continued this year.…”

LOCA Fragmentation Test with High Burnup HBR Fuel Rod

“…SATS was installed in the ORNL 3525 Hot Cell in 2017. 11 Several LOCA benchmark tests were performed with unindicated Zry-4 cladding specimens before and after the installation. 12 For irradiated fuels, specimen fabrication for the LOCA fragmentation testing includes fuel rod sectioning, metallographic mounting and polishing, fuel leaching, outer oxide layer removal, inner fuel/cladding bond layer and fuel removal, and end-plug welding.…”

“…The high-temperature steam oxidation behavior of zirconium alloy cladding under design basis LOCAs and over a broader set of conditions has been studied at several facilities around the world. [2][3][4][5][6][7][8][9] 10,11 SATS consists of two modules: one for integral testing of LOCA scenarios and the other with a high-temperature furnace for testing fuel segments.…”