• 제목/요약/키워드: Decay Heat

검색결과 248건 처리시간 0.03초

Thermodynamic Study of Sequential Chlorination for Spent Fuel Partitioning

  • Jinmok Hur;Yung-Zun Cho;Chang Hwa Lee
    • 방사성폐기물학회지
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    • 제21권3호
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    • pp.397-410
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    • 2023
  • This study examined the efficacy of various chlorinating agents in partitioning light water reactor spent fuel, with the aim of optimizing the chlorination process. Through thermodynamic equilibrium calculations, we assessed the outcomes of employing MgCl2, NH4Cl, and Cl2 as chlorinating agents. A comparison was drawn between using a single agent and a sequential approach involving all three agents (MgCl2, NH4Cl, and Cl2). Following heat treatment, the utilization of MgCl2 as the sole chlorinating agent resulted in a moderate separation. Specifically, this method yielded a solid separation with 96.9% mass retention, 31.7% radioactivity, and 44.2% decay heat, relative to the initial spent fuel. In contrast, the sequential application of the chlorinating agents following heat treatment led to a final solid separation characterized by 93.1% mass retention, 5.1% radioactivity, and 15.4% decay heat, relative to the original spent fuel. The findings underscore the potential effectiveness of a sequential chlorination strategy for partitioning spent fuel. This approach holds promise as a standalone technique or as a complementary process alongside other partitioning processes such as pyroprocessing. Overall, our findings contribute to the advancement of spent fuel management strategies.

Thermal and Non-thermal Heat Flow in a Large Crystal Detector for Neutrinoless Double Beta Decay Search

  • Kim, G.B.;Lee, S.J.;Jang, Y.S.;Lee, H.J.;Lee, J.H.;Lee, J.Y.;Lee, M.K.;Yoon, W.S.;Kim, Y.H.
    • Progress in Superconductivity
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    • 제14권2호
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    • pp.87-91
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    • 2012
  • Metallic magnetic calorimeters (MMCs) are one of the most competitive low temperature detector (LTD) readout sensors. They have the advantages of high time resolution, no heat dissipation, and a wide range of operating temperature. We apply MMCs to our neutrinoless double beta decay ($0v{\beta}{\beta}$) search experiment. A $CaMoO_4$ crystal was employed as both a source of $0v{\beta}{\beta}$ and an energy absorber. The crystal was thermally connected to a MMC sensor. We set a simple thermal model for this detector and measured pulse shapes are compared with a numerical solution of the thermal model.

수소동위원소 계량·공급기술 (Hydrogen Isotopes Accountancy and Storage Technology)

  • 구대서;정흥석;정동유;이정민;윤세훈;조승연;정기정
    • 한국수소및신에너지학회논문집
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    • 제23권1호
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    • pp.49-55
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    • 2012
  • Hydrogen isotopes accountancy and storage are important functions in a nuclear fusion fuel cycle. The hydrogen isotopes are safely stored in metal hydride beds. The tritium inventory of the bed is determined from the decay heat of tritium. The decay heat is measured by circulating helium through the metal hydride bed and measuring the resultant temperature increase of the helium flow. We are reporting our preliminary experimental results on the hydrogen isotopes accountancy and storage performance in a metal hydride bed.

GAS-COOLED FAST REACTORS_DHR SYSTEMS, PRELIMINARY DESIGN AND THERMAL- HYDRAULIC STUDIES

  • Malo, J.Y.;Bassi, C.;Cadiou, T.;Blanc, M.;Messie, A.;Tosello, A.;Dumaz, P.
    • Nuclear Engineering and Technology
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    • 제38권2호
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    • pp.129-138
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    • 2006
  • The Gas-cooled Fast Reactor (GFR) is one of the six reactor concepts selected within the framework of the Generation IV initiative and is the reference concept for the Commissariat $\grave{a}$ l'Energie Atomique $(CEA^1)$. Two reactor unit sizes have been considered: 600 MWth and 2400 MWth. As far as thermal-hydraulics is concerned, reactor decay heat removal (DHR) proves to be a major issue. The CEA has conducted exploratory design studies to address this issue and a reference solution for the 600MWth reactor has been recommended.

Spent fuel characterization analysis using various nuclear data libraries

  • Calic, Dusan;Kromar, Marjan
    • Nuclear Engineering and Technology
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    • 제54권9호
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    • pp.3260-3271
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    • 2022
  • Experience shows that the solution to waste management in any national programme is lengthy and burdened with uncertainties. There are several uncertainties that contribute to the costs associated with spent fuel management. In this work, we have analysed the impact of the current nuclear data on the isotopic composition of the spent fuel and consequently their influence on the main spent fuel observables such as decay heat, activity, neutron multiplication factor, and neutron and photon source terms. Nuclear libraries based on the most general nuclear data ENDF/B-VII.0, ENDF/B-VII.1, ENDF/B-VIII.0 and JEFF-3.3 are considered. A typical NPP Krško fuel assembly is analysed using the Monte Carlo code Serpent 2. The analysis considers burnup of up to 60 GWd/tU and cooling times of up to 100 years. The comparison of results showed significant differences, which should be taken into account when selecting the library and evaluating the uncertainty in determining the characteristics of the spent fuel.

Burnable poison optimized on a long-life, annular HTGR core

  • Sambuu, Odmaa;Terbish, Jamiyansuren
    • Nuclear Engineering and Technology
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    • 제54권8호
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    • pp.3106-3116
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    • 2022
  • The present work presents analysis results of the core design optimizations for an annular, prismatic High Temperature Gas-cooled Reactor (HTGR) with passive decay-heat removal features. Its thermal power is 100 MWt and the operating temperature is 850 ℃ (1123 K). The neutronic calculations are done for the core with heterogeneous distribution of fuel and burnable poison particles (BPPs) to flatten the reactivity swing and power peaking factor (PPF) during the reactor operation as well as for control rod (CR) insertion into the core to restrain a small excess reactivity less than 1$. The next step of the study is done for evaluation of core reactivity coefficient of temperature.