The Corrosion of Aluminium Alloy and Release of Intermetallic Particles in Nuclear Reactor Emergency Core Coolant: Implications for Clogging of Sump Strainers

Junlin Huang,Derek Lister,Shunsuke Uchida,Lihui Liu 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.5

Clogging of sump strainers that filter the recirculation water in containment after a loss-of-coolant accident(LOCA) seriously impedes the continued cooling of nuclear reactor cores. In experiments examiningthe corrosion of aluminium alloy 6061, a common material in containment equipment, in boratedsolutions simulating the water chemistry of sump water after a LOCA, we found that Fe-bearing intermetallicparticles, which were initially buried in the Al matrix, were progressively exposed as corrosioncontinued. Their cathodic nature vis- a-vis the Al matrix provoked continuous trenching around themuntil they were finally released into the test solution. Such particles released from Al alloy components ina reactor containment after a LOCA will be transported to the sump entrance with the recirculation flowand trapped by the debris bed that typically forms on the strainer surface, potentially aggravatingstrainer clogging. These Fe-bearing intermetallic particles, many of which had a rod or thin strip-likegeometry, were identified to be mainly the cubic phase ac-Al(Fe,Mn)Si with an average size of about2.15 mm; 11.5 g of particles with a volume of about 3.2 cm3 would be released with the dissolution ofevery 1 kg 6061 aluminium alloy.

Impedance investigation of the surface film formed on aluminum alloy exposed to nuclear reactor emergency core coolant

Huang Junlin,Lister Derek,Zhu Xiaoliang,Uchida Shunsuke,Xu Qinglan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

A method was proposed for in-situ evaluating the thickness and resistivity of the oxide/hydroxide film formed on the surface of aluminum alloy exposed to sump water formed in the containment after a loss-of-coolant accident. The evaluation entailed fitting a model for the film impedance, which has film thickness and other variables describing the resistivity profile of the film along its thickness direction as fitting parameters, to the practically measured electrochemical impedance data. The obtained resistivity profiles implied that the films formed at pHs25°C 7, 8, 9, 10, and 11 all had a duplex structure; compared to the outer layer in contact with the solution, the inner layer of the film had a much higher resistivity and was inferred to be denser and provide most of the protectiveness of the film. Both the thickness and the total resistance of the film decreased with the increasing solution pH25°C, suggesting that the films formed in more alkaline solutions had less protectiveness against corrosion, consistent with the increasing aluminum alloy corrosion rates previously identified.

A simple electrospinning strategy to achieve the uniform distribution of ultra‑fine CoP nanocrystals on carbon nanofibers for efficient lithium storage

Qinghua Wang,Wei Wang,Junlin Huang,Hong Yin,Yucan Zhu,Haitao Wang,Minjie Zhou,Binhong He,Zhaohui Hou,Wenyuan Xu 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Transition-metal phosphides (TMPs), a promising anode material for lithium-ion batteries (LIBs), are limited in application because of its serious volume effect in the cycle. In this work, a simple electrospinning strategy was proposed to restrict the grain size of CoP nanocrystals by nano-confined effect of carbon nanofibers with ligands. The addition of ligands not only could realize the uniform dispersion of CoP nanocrystals, but also strengthen the bond between the metals and carbon nanofibers. As a result, the CoP/CNF composite exhibits excellent lithium storage performance, and its reversible specific capacity could reach 1016.4 mAh g? 1 after 200 cycles at a current density of 200 mA g? 1. The research is anticipated to provide a new idea for the preparation of anode materials for lithium ion batteries.

Magnetic Resonance Imaging–Detected Intracranial Extension in the T4 Classification Nasopharyngeal Carcinoma with Intensity-Modulated Radiotherapy

Caineng Cao,Jingwei Luo,Li Gao,Junlin Yi,Xiaodong Huang,Suyan Li,Jianping Xiao,Zhong Zhang,Guozhen Xu 대한암학회 2017 Cancer Research and Treatment Vol.49 No.2

Purpose This study was conducted is to identify the prognostic value and staging categories of magnetic resonance imaging (MRI)–detected intracranial extension in nasopharyngeal carcinoma (NPC) with intensity-modulated radiotherapy (IMRT) to determine whether it is necessary to subclassify the T4 classification NPC. Materials and Methods A total of 335 nonmetastatic T4 classification NPC patients with MRI treated between March 2004 and June 2011 by radical IMRT were included. The T4 classification patients were subclassified into two grades (T4a, without intracranial extension vs. T4b, with intracranial extension) according to the site of invasion. Results The frequency of intracranial extension was 40.9% (137 of 335 patients). Multivariate analysis identified subclassification (T4a vs. T4b) as an independent prognostic factor for local failure-free survival (p=0.049; hazard ratio [HR], 0.498) and overall survival (p=0.004; HR, 0.572); however, it had no effect on regional failure-free survival or distant failure-free survival (p > 0.050). Conclusion For patients with T4 classification NPC, those with MRI-detected intracranial extension are more likely to experience local failure and death after IMRT than patients without intracranial extension. According to the site of invasion, subclassification of T4 patients as T4a or T4b has prognostic value in NPC.

Preparation of self‑supporting Co3S4/ S‑rGO film catalyst for efficient oxygen evolution reaction

Liang Chen,Liying Hu,Chenxi Xu,Lanyun Yang,Wei Wang,Junlin Huang,Minjie Zhou,Zhaohui Hou 한국탄소학회 2023 Carbon Letters Vol.33 No.7

Exploring cheap and efficient oxygen evolution reaction (OER) catalysts is extremely vital for the commercial application of advanced energy storage and conversion systems. Herein, a self-supporting Co3S4/ S-doped reduced graphene oxide ( Co3S4/S-rGO) film catalyst is successfully prepared by a blade coating coupled with high-temperature annealing strategy, and its morphology, structure and composition are measured and analyzed. It is substantiated that the as-synthesized Co3S4/ S-rGO film possesses unique self-supporting structure, and is composed of uniformly dispersed Co3S4 nanoparticles and highly conductive S-rGO, which benefit the exposure of catalytic sites and electron transfer. By reason of the synergistic effect of the two individual components, the self-supporting Co3S4/ S-rGO film catalyst displays outstanding catalytic performance towards OER. As a consequence, the Co3S4/ S-rGO film catalyst delivers an overpotential of 341 mV at 10 mA cm-2, and the current attenuation rate is only 2.6% after continuous operation for 4 h, verifying excellent catalytic activity and durability. Clearly, our results offers a good example for the construction of high-performance self-supporting carbon-based composite film catalysts for critical electrocatalytic reactions.

Mutations of ARX and non-syndromic intellectual disability in Chinese population

Yufei Wu,Huan Zhang,Xiaofen Liu,Zhangyan Shi,Hongling Li,Zhibin Wang,Xiaoyong Jie,Shao-Ping Huang,Fu-Chang Zhang,Junlin Li,Ke-Jin Zhang,Xiao-Cai Gao 한국유전학회 2019 Genes & Genomics Vol.41 No.1

Mutations of Aristaless-related homeobox (ARX) gene were looked as the third cause of non-syndromic intellectual disability (NSID), while the boundary between true disease-causing mutations and non-disease-causing variants within this gene remains elusive. To investigate the relationship between ARX mutations and NSID, a panel comprising six reported causal mutations of the ARX was detected in 369 sporadic NSID patients and 550 random participants in Chinese. Two mutations, c.428_451 dup and p.G286S, may be disease-causing mutations for NSID, while p.Q163R and p.P353L showed a great predictive value in female NSID diagnosis with significant associations (X2 = 19.60, p = 9.54e−6 for p.Q163R; X2 = 25.70, p = 4.00e−07 for p.P353L), carriers of these mutations had an increased risk of NSID of more than fourfold. Detection of this panel also predicted significant associations between genetic variants of the ARX gene and NSID (p = 3.73e−4). The present study emphasized the higher genetic burden of the ARX gene on NSID in the Chinese population, molecular analysis of this gene should be considered for patients presenting NSID of unknown etiology.

Study on the mixing performance of mixing vane grids and mixing coefficient by CFD and subchannel analysis code in a 5×5 rod bundle

Han Bin,Zhu Xiaoliang,Yang Bao-Wen,Liu Aiguo,Xi Yanyan,Liu Lei,Liu Shenghui,Huang Junlin 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.10

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.