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Gerardi, Craig

Publications and source records attributed to Gerardi, Craig.

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Fiscal Year 2018 Sodium-CO2 Interaction Test

An experiment campaign was continued in Fiscal Year 2018 in the Argonne National Laboratory (Argonne) SNAKE facility that investigated the interactions between supercritical carbon dioxide (sCO 2 ) and sodium through injection of sCO 2 into an open surface sodium pool. Two of fifteen previous SNAKE tests revealed that self-plugging of the leakage path/nozzle occurs at higher initial sodium temperatures of about 500 ºC due to chemical reactions involving CO 2 , sodium, and sodium-CO 2 reaction products. At lower sodium temperatures, the interaction phenomena involve consumption of injected CO 2 and formation of an agglomerated mass of reaction products without self-plugging. The FY 2018 test investigated interactions at an intermediate initial sodium temperature of about 411 ºC, representative of the interior of a sodium-to-CO 2 heat exchanger in a Sodium-Cooled Fast Reactor (SFR) sCO 2 Brayton Cycle energy conversion system. The experiment was successfully conducted and did not show self-plugging as evidenced by a sustained chemical reaction between the injected CO 2 and sodium and consumption of CO 2 .

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2018

Development of Process for Cleanup of Sodium-CO 2 Reaction Products

This study describes Argonne’s recent experience in cleaning several kilograms of sodium mixed with solid reaction products formed bysodium-CO 2 interaction. One of the reaction products is carbon monoxide (CO) and precautions have to be taken to protect personnel from exposure to CO. Ethanol was an effective method to clean and dispose of small amounts of residual reaction products embedded in a sodium matrix. Ideally, the residual sodium should be melted out of the parts as possible in order to reduce the amount of time it would take to clean with ethanol since this process is slow.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

FY2017 Sodium-CO2 Interaction Tests

An experimental campaign was carried out in Fiscal Year 2017 in the ANL SNAKE facility that investigated the interaction between sCO 2 and sodium through injection of sCO 2 into a sodium-filled diffusion-bonded heat exchanger channel mock-up. This successful experiment demonstrated that a sustained chemical reaction between the injected CO 2 and sodium occurred at temperatures representative of the cold leg of an intermediate heat transport system for a SFR-to-sCO 2 Brayton Cycle energy conversion system. Evidence of the chemical reaction included: exothermic heatup of localized regions of the test vessel, production of carbon monoxide, consumption of CO 2 and production of solid reaction products that were observed during post-test examination. This experimental result was consistent with previous SNAKE experiments. Two of fourteen previous SNAKE tests confirmed that self-plugging of the leakage path/nozzle could occur at higher initial s odium temperatures due to chemical reactions involving CO 2 , sodium, and sodium-CO 2 reaction products. The remaining tests, including the one carried out in Fiscal Year 2017, began with low er initial temperatures and did not self-plug. A new model was developed to determine the reaction rate constant for sCO 2 injections into sodium by calculating the increase of bulk sodium temperature. This model will be developed further and used to simulate the behavior of reactor-scale sodium-to-sCO 2 heat exchanger failures.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2017

Experimental studies on metallic fuel relocation in a single-pin core structure of a sodium-cooled fast reactor

Experiments dropping molten uranium into test sections of single fuel pin geometry filled with sodium were conducted to investigate relocation behavior of metallic fuel in the core structures of sodium-cooled fast reactors during a hypothetical core disruptive accident. Metallic uranium was used as a fuel material and HT-9M was used as a fuel cladding material in the experiment in order to accurately mock-up the thermo-physical behavior of the relocation. The fuel cladding failed due to eutectic formation between the uranium and HT-9M for all experiments. The extent of the eutectic formation increased with increasing molten uranium temperature. Voids in the relocated fuel were observed for all experiments and were likely formed by sodium boiling in contact with the fuel. In one experiment, numerous fragments of the relocated fuel were found. In conclusion, it could be concluded that the injected metallic uranium fuel was fragmented and dispersed in the narrow coolant channel by sodium boiling

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗