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TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
B.-G. Brodda, D. Heinen
Nuclear Technology | Volume 34 | Number 3 | August 1977 | Pages 428-437
Technical Paper | Chemical Processing | doi.org/10.13182/NT77-A31808
Articles are hosted by Taylor and Francis Online.
Radiolysis and hydrolysis of tributylphosphate (TBP) in n-paraffin diluent were investigated under conditions simulating several parameters of the THOREX flowsheet for reprocessing thorium containing spent nuclear fuel. The solvent (30 vol% TBP-n-paraffin) was equilibrated with 0.25 to 3 molar nitric acid, and the organic phase was inspected by gas chromatography. As an acid hydrolysis product, only di-n-butylphosphoric acid (HDBP) was detected in the organic phase. Mono-n-butylphosphoric acid (H2MBP), if formed, would have been extracted into the aqueous phase and, thus, escape detection. The HDBP content of the organic phase changes linearly with its acid content and keeps constant after phase separation. Either hydrolysis does not proceed in the organic phase or it is compensated for by amelioration effects. Radiolysis in pure solvents (30 and 5 vol% TBP-n-paraffin) with doses from 0.5 to 13 Wh·ℓ−1 produces HDBP with G values (TBP-based) of ∼2 and ∼6, slightly decreasing with higher doses. No H2MBP was found. Regarding the analytical detection limit, this corresponds to <2.5% H2MBP formation, relative to HDBP. Radiolysis in solvent (30 vol% TBP-n-paraffin), equilibrated with 0.25 to 3 molar nitric acid at a constant dose of 7 Wh·ℓ−1, leads to a considerably reduced radiolytic fraction of the total HDBP yield with a minimum of ∼0.3 molar nitric acid in the organic phase (2 molar in the aqueous phase). At ∼0.17 molar nitric acid in the organic phase (corresponding to THOREX conditions), radiolytic and hydrolytic fractions are equal. With higher acidities, the hydrolytic fraction preponderates and vice versa. The G values of the radiolytic fraction vary between 0.8 and 1.1. Again, the H2MBP formation was not detected at the same sensitivity level. Irradiating the solvent (30 vol% TBP-n-paraffin), equilibrated with 0.75 molar nitric acid (0.12 molar in the organic phase) with doses from 0.5 to 13 Wh·ℓ−1, leads to a mixture of hydrolytically and radiolytically formed HDBP, the hydrolytic fraction of which raises the total HDBP yield over the radiolytic HDBP yield from acid-free solvents up to doses of ∼3 Wh·ℓ−1. With higher doses, the total yield is kept below the value for the acid-free solvent due to the nitric acid effect. The G values of the radiolytic fraction vary between 0.7 and 1.2. Again, the H2MBP formation could not be detected. It is proposed to denominate TBP degradation product yields according to their origin, hydrolysis or radiolysis (G value), or just by a concentration value in case of mixed origin, valid for the experimental conditions.
