Abstract
The primary salt pump installed in the high-temperature FLUoride Salt Test Facility (FLUSTFA) was successfully operated for some time, but later ceased operation. To understand what occurred, a Root Cause Analysis (RCA) was performed. Steps taken to try to get the pump operational include adjusting the shaft position, increasing the heating power of the tape heaters on the pump volute, and manually rotating the pump shaft. While removing the insulation, corrosion was noted on the outside of the pump volute, and decolorization of the insulation and tape heaters was observed. Significant corrosion products were also observed in the pump itself and the piping connected to the pump. The nitrogen cover gas was maintained from before salt was introduced into the loop until the pump was dismounted and continues to be maintained even after the pump was removed. After considering probable scenarios, causes were assigned and corrective actions were developed to prevent those causes. Then, the RCA was presented to an advisory committee for review, the “Review Committee,” consisting of experts in large molten salt systems: Brandon Haugh, David Holcomb, Kevin Robb, and Vicente Rojas. The advisory committee provided comprehensive feedback, which have been incorporated into a revised RCA. Findings have then been summarized and reported in this publication.
| Original language | English |
|---|---|
| Article number | 114365 |
| Journal | Nuclear Engineering and Design |
| Volume | 444 |
| DOIs | |
| State | Published - Dec 1 2025 |
Funding
This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( https://www.energy.gov/doe-public-access-plan ). The authors wish to express their sincere gratitude to the members of the Review Committee: Brandon Haugh, David Holcomb, Kevin Robb, and Vicente Rojas. Their insightful feedback was invaluable in deepening our understanding of the underlying causes, and their thoughtful recommendations for mitigating actions were instrumental in shaping strategies to prevent similar issues in future systems. We also thank High Temperature Systems Design and Nagle Pump for their consultation while the failure was ongoing, and afterwards, which contributed to our analysis. This research was performed using funding received from the Department of Energy (DOE) Advanced Research Projects Agency- Energy (ARPA-E), project award number DE-AR0001297. The authors appreciate the financial support. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (https://www.energy.gov/doe-public-access-plan). This research was performed using funding received from the Department of Energy (DOE) Advanced Research Projects Agency- Energy (ARPA-E), project award number DE-AR0001297. The authors appreciate the financial support.