• Title/Summary/Keyword: Burn units

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Neutronic optimization of thorium-based fuel configurations for minimizing slightly used nuclear fuel and radiotoxicity in small modular reactors

  • Nur Anis Zulaikha Kamarudin;Aznan Fazli Ismail;Mohamad Hairie Rabir;Khoo Kok Siong
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2641-2649
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    • 2024
  • Effective management of slightly used nuclear fuel (SUNF) is crucial for both technical and public acceptance reasons. SUNF management, radiotoxicity risk, and associated financial investment and technological capabilities are major concerns in nuclear power production. Reducing the volume of SUNF can simplify its management, and one possible solution is utilizing small modular reactors (SMR) and advanced fuel designs like those with thorium. This research focuses on studying the neutronic performance and radionuclide inventory of three different thorium fuel configurations. The mass of fissile material in thorium-based fuel significantly impacts Kinf, burn-up, and neutron energy spectrum. Compared to uranium, thorium as a fuel produces far fewer transuranic elements and less long-lived fission products (LLFPs) at the end of the core cycle (EOC). However, certain fission product elements produced from thorium-based fuel exhibit higher radioactivity at the beginning of the core cycle (BOC). Physical separation of thorium and uranium in the fuel block, like seed-and-blanket units (SBU) and duplex fuel designs, generate less radioactive waste with lower radioactivity and longer cycle lengths than homogeneous or mixed thorium-uranium fuel. Furthermore, the SBU and duplex feel designs exhibit comparable neutron spectra, leading to negligible differences in SUNF production between the two.

Modeling of a Compressed Air Energy Electrification by Using Induction Generator Based on Field Oriented Control Principle

  • Vongmanee, Varin;Monyakul, Veerapol
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1511-1519
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    • 2014
  • The objective of this paper is to propose a modelling of a small compressed air energy storage system, which drives an induction generator based on a field-oriented control (FOC) principle for a renewable power generation. The proposed system is a hybrid technology of energy storage and electrification, which is developed to use as a small scale of renewable energy power plant. The energy will be transferred from the renewable energy resource to the compressed air energy by reciprocating air compressor to be stored in a pressurized vessel. The energy storage system uses a small compressed air energy storage system, developed as a small unit and installed above ground to avoid site limitation as same as the conventional CAES does. Therefore, it is suitable to be placed at any location. The system is operated in low pressure not more than 15 bar, so, it easy to available component in country and inexpensive. The power generation uses a variable speed induction generator (IG). The relationship of pressure and air flow of the compressed air, which varies continuously during the discharge of compressed air to drive the generator, is considered as a control command. As a result, the generator generates power in wide speed range. Unlike the conventional CAES that used gas turbine, this system does not have any combustion units. Thus, the system does not burn fuel and exhaust pollution. This paper expresses the modelling, thermodynamic analysis simulation and experiment to obtain the characteristic and performance of a new concept of a small compressed air energy storage power plant, which can be helpful in system designing of renewable energy electrification. The system was tested under a range of expansion pressure ratios in order to determine its characteristics and performance. The efficiency of expansion air of 49.34% is calculated, while the efficiency of generator of 60.85% is examined. The overall efficiency of system of approximately 30% is also investigated.

Effectiveness of Simple Trauma Team Activation Criteria on Prognosis of Severe Trauma Patients (단순 외상팀 활성화 조건이 중증 외상 환자의 치료 결과에 미치는 영향)

  • Lee, Dong Keon;Lee, Kang Hyun;Cha, Kyoung Chul;Park, Kyoung Hye;Choi, Han Joo;Kim, Hyun;Hwang, Sung Oh
    • Journal of Trauma and Injury
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    • v.22 no.1
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    • pp.71-76
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    • 2009
  • Purpose: The goal of this study was to compare the outcome of the after trauma team (AfterTT) group to the before trauma team (BeforeTT) group. Methods: All trauma patients who visited to emergency room (ER) between July 1, 2006 and February 29,2008 based on trauma registry, with systolic blood pressure (SBP) < 90 mmHg or GCS < 9 were included in this study. We compared the amount of packed RBC transfusion, the ER stay time, the ER visit to CT evaluation time, the ER visit to operation time, the length of ICU stay, the length of hospital admission and the survival discharge rate between the AfterTT group and the BeforeTT group. Patients with brain injuries had little chance of survival. Burn patients, who visited the ER 24 hours after injury and patients who were dead on arrival (DOA) were excluded from this study. Results: Total of 93 patients were included in this study: 42 in the AfterTT group and 51 in the BeforeTT group. The AfterTT group and the Before TT group showed no differences in Revised Trauma Score (RTS) and mean age. The amount of packed RBC transfusion was lower in the AfterTT group, but no statistically significant difference was noted (AfterTT 11${\pm}$11units, BeforeTT 16${\pm}$15units, p=0.136). The ER visit to operation time was shorter in the AfterTT group, but there were no statistically significant difference between the groups (AfterTT 251${\pm}$223 minutes, BeforeTT 486${\pm}$460 minutes, p=0.082). The length of ICU stay was shorter in the AfterTT group, but the difference was not statistically significant (AfterTT 11${\pm}$12 days, Before TT 15${\pm}$30 days, p=0.438). The length of Hospital admission was shorter in the AfterTT group (AfterTT 43${\pm}$37 days, BeforeTT 68${\pm}$70 days, p=0.032), but this difference was not statistically significant. Conclusion: Simple Trauma team activation criteria decreased the amount of packed RBC transfusion and the hospital admission duration. Hemodynamic instability (SBP < 90 mmHg) and decreased mental state (GCS<9) are good indices for activating the trauma team.