China National Nuclear Corporation Research Articles

Effectiveness of respiratory training in home-based pulmonary rehabilitation for elderly patients with stable COPD: Study protocol for a randomized controlled trial

Introduction: Chronic Obstructive Pulmonary Disease (COPD) brought a heavy risk of morbidity, hospital admission, and death. Respiratory training as an important part of pulmonary rehabilitation has not been validated in home-based elderly patients with stable COPD. This study aims to demonstrate the efficacy of a standardized respiratory training in home-based elderly patients with stable COPD. Methods: The prospective, randomized controlled trial will be designed and conduced in the Second Affiliated Hospital of Chengdu Medical College (China National Nuclear Corporation 416 Hospital),China. Eligible patients with stable COPD will be randomly divided into experimental group and control group, both of the 2 groups will carry out regular home-based pulmonary rehabilitation for 3 months, additionally experimental group will receive a standardized respiratory training for 3 months. The primary outcome is the pulmonary function test before and after 3 months exercises. Discussion: The study will provide a objective basis for the use of respiratory training in home-based pulmonary rehabilitation for elderly patients with stable COPD.

Validation of PWR Neutronics Code Package TORCH V2.0 With Nuclear Power Plant Measurements

This article presents the verification and validation (V and V) of PWR neutronics code package TORCH V2.0 with nuclear power plant (NPP) measurements. The advanced nuclear power engineering design software, TORCH V2.0, was developed by the Nuclear Power Institute of China (NPIC), China National Nuclear Corporation (CNNC). Based on the two-step calculation scheme, TORCH V2.0 mainly contains lattice physics code for assembly homogenization, link calculation code for few-group constant parameterization, and core simulation code for few-group core calculation. The calculation modules of each code were already verified against various benchmark problems, whereas this article focuses on the V and V of linked code system. The measured values of the reactor startup physics test and NPP operation from six PWR NPPs (Daya Bay NPP, Ling Ao NPP, Fangjiashan NPP, Qinshan NPP, Hainan Changjiang NPP, and Fuqing NPP) were utilized to perform the comparison and analysis of V and V. Compared parameters of the reactor startup physics test include critical boron concentration, control rod integral value, boron differential value, and isothermal temperature coefficient. Compared parameters of the NPP operation contain critical boron concentration, assembly-wise power distribution, hot spot factor, and nuclear enthalpy rise factor. The results show that the software TORCH V2.0 has reliable calculation ability and can be applied in the PWR nuclear power engineering design which is based on square fuel assembly.

Status of the Domestic Large Helium Refrigeration System of HL-2M Tokamak

HL-2M, the satellite tokamak of ITER (International Thermonuclear Experimental Reactor), has successfully completed the first plasma experiment in December 2020 in Southwestern Institute of Physics, China National Nuclear Corporation (CNNC-SWIP). The 500 W/4.5 K helium cryogenic system used in HL-2M is mainly used to cool down the cryopumps and superconducting magnets. The refrigeration system is the heart components of the cryogenic system. The design and development of the refrigeration system witness our significant cooperation with Fullcryo Company. The refrigeration system has completed the factory commissioning and on-site installation at the end of 2019. This paper presents the performance characteristics of the main key equipment in the system.

The Engineering Commissioning of the Magnets System On HL-2M Tokamak

HL-2M tokamak is one of largest magnetic confinement fusion devices designed and constructed by Southwestern Institute of Physics (SWIP), China National Nuclear Corporation (CNNC), the first plasma was obtained on December, 4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> , 2020. The magnets system which plays an important role for the plasma confinement consists of 20 toroidal field (TF) coils and 18 poloidal field (PF) coils. The magnets system commissioning was carried out by two phases: self-commissioning and integrated commissioning. The first phase: self-commissioning including joint resistance commissioning, turn to turn insulation commissioning, ground insulation commissioning, deionized water sealing commissioning was accomplished during the installation and test of the magnets system. The second phase: the integrated commissioning with power supply system, ground system, measurement and data acquisition system, plasma control system, interlock and safety system was accomplished based on the results of the first stage. The total commissioning of magnets system in HL-2M tokamak for the first plasma have been accomplished successfully.

Study on Characteristics of the Helium Refrigeration System of HL-2M Tokamak

HL-2M, a new generation of tokamak, has been built continuously in 2020 in Southwestern Institute of Physics, China National Nuclear Corporation, and the first plasma discharge was successfully achieved in 12th, Dec. This tokamak experiment device has high design parameters, and its maximum operating current reaches 3 MA. As a satellite device of ITER, it aims to explore and solve the severe physical and engineering problems. Cryogenic system is an auxiliary system of HL-2M, which mainly meets the stable operation of cryopumps and superconducting magnets. The refrigeration capacity under the condition of Liquid Nitrogen Precooling will up to 500W@4.5K, the liquefaction rate is 160L/h. In this report, we present the main characteristic parameters of the refrigeration system. At present, the system has completed the field assembly, and is expected to start commissioning in June 2021.

Research and Implementation of SVDU Simulator Based on Emulation Technology

The safety video display unit (SVDU), as the display machine of the reactor protection system, performs the functions of displaying the reactor’s safety parameters and sending safety control commands. In order to meet the needs of nuclear power safety-level digital control system (DCS), like designing verification, operator training, and accidental drills, for the SVDU in the NASPIC platform developed independently by China National Nuclear Corporation, a virtual embedded system technology based on the micro x86 industrial host is proposed to make software simulation to the SVDU physical controller with exactly the same hardware appearance of the original one. The SVDU stimulator realized by this research can achieve 100% simulation of the logical functions of the SVDU physical equipment and the synchronized upgrading function between stimulator and the real equipment. With the development of multiple engineering application requirements, such as configuration verification and operator training, this stimulator has been applied in several virtual security level DCS projects.

MULTIPLE CHOICES OF REACTOR CORE NUCLEAR DESIGN FOR ACP100’S APPLICATION IN DIFFERENT SCENARIOS

ACP100 NPP designed by CNNC (China National Nuclear Corporation) is a 125MWe, multi-purpose small modular reactor based on pressurized water reactor technology; it adopts the integrated reactor technology. Different application scenarios bring up different design requirements: some require high compactness, but others care more about a longer cycle length, and some may require a fully mature and conservative design; thus, multiple design choices need to be proposed. Also, the same and most important thing cared by all users is that, the design needs to be validated to satisfy the current nuclear safety standards, and lower cost would be always preferred. Core nuclear design is a key part of the whole NPP design. Basically, nuclear design target of ACP100 is to achieve a reasonable good balance during longer cycle length, larger discharge exposure for fuel assemblies, and maximally using the mature technologies, and of course, with sufficient reactivity control ability for safety assurance. Aiming at satisfying all these different needs maximally, a strategy of supplying multiple nuclear design choices is proposed for ACP100: choice 1. Boron-free plan, this is a compact design with no need for chemistry and volume system, no need for daily boron adjustment and relative waste storage; choice 2. Boron and rod co-controlled plan, this is similar with large commercial PWRs, with a lower power peak factor and suitable for broad location sites. Both choices load 57 units of the same type fuel assemblies CF3S (with height reduced from CF3 fuel assemblies) per cycle, and both adopt partial reload and shuffle fuel management strategy to achieve larger discharge exposure. Gd is loaded in the fuel rods in both choices to help control reactivity. Choice 1 loads much more control rod clusters than choice 2, and of course, reactivity adjustment and compensation during operation is totally different between them. Using suitable and reliable software to simulate the core, through large amount of optimization, both choices achieve a 24-month fuel cycle length; the average discharge exposure of fuel assemblies reach about 40000MWd/tU, which is competitive among SMRs, especially for boron-free ones; and sufficient reactivity control ability and safety margin is validated to fully meet the reactor safety requirements.

China is speeding up its plutonium recycling programs

ABSTRACT Since 1983, China has had the objective of developing breeder reactors to run on recycled plutonium. Since 2004, it has been progressing through three stages of its plutonium recycling strategy: from pilot to demonstration to commercial facilities. At the first stage, in 2010, China began testing a pilot civilian reprocessing plant and running a small experimental fast reactor. Although those pilot facilities did not perform well, since 2015 China has moved forward to the second stage, which includes a demonstration reprocessing plant, a mixed-oxide fuel facility, and two demonstration liquid-sodium-cooled fast-neutron reactors. Recent satellite images and other information show construction of those demonstration facilities is actively underway. Meanwhile, the China National Nuclear Corporation is pushing toward the third stage by negotiating with France’s nuclear fuel cycle company Orano (formerly Areva) over the purchase of a large commercial reprocessing plant, and has proposed construction of large commercial fast-neutron reactors by 2028.

Status of the cryogenic system of the HL-2M tokamak

In the efforts of obtaining a more pronounced plasma shape, the HL-2A tokamak at the Southwestern Institute of Physics, China National Nuclear Corporation (CNNC-SWIP) is currently being upgraded to possess a more powerful, compact and efficient divertor. The now HL-2M tokamak is comprised of a 500 W/4.5 K helium refrigerator for the combined cooling of cryopumps, superconducting magnets and thermal shields. The construction of the helium management system was finished last year. The manufacturing and assembling of the refrigerator were finished in August of 2019, and the refrigerator will be commissioned toward the end of this year. The installation of the cryogenic distribution system will be finished in February of 2020. The first commissioning of the entire system will be soon after five months. This paper presents the design and the construction states of the HL-2M cryogenic system.

Segregation behavior and embrittling effect of lanthanide La, Ce, Pr, and Nd at Σ3(111) tilt symmetric grain boundary in α-Fe**Project supported by the National Natural Science Foundation of China (Grant No. U1867217), the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2019ZX06004009), and the China National Nuclear Corporation Centralized Research and

The migration of lanthanide fission products to cladding materials is recognized as one of the key causes of fuel–cladding chemical interaction (FCCI) in metallic fuels during operation. We have performed first-principles density functional theory calculations to investigate the segregation behavior of lanthanide fission products (La, Ce, Pr, and Nd) and their effects on the intergranular embrittlement at Σ3(111) tilt symmetric grain boundary (GB) in α-Fe. It is found that La and Ce atoms tend to reside at the first layer near the GB with segregation energies of −2.55 eV and −1.60 eV, respectively, while Pr and Nd atoms prefer to the core mirror plane of the GB with respective segregation energies of −1.41 eV and −1.50 eV. Our calculations also show that La, Ce, Pr, and Nd atoms all act as strong embrittlers with positive strengthening energies of 2.05 eV, 1.52 eV, 1.50 eV, and 1.64 eV, respectively, when located at their most stable sites. The embrittlement capability of four lanthanide elements can be determined by the atomic size and their magnetism characters. The present calculations are helpful for understanding the behavior of fission products La, Ce, Pr, and Nd in α-Fe.

Development of positioning system for Nuclear-fuel rod automated assembly

Abstract A heavy-water nuclear reactor requires five different types of nuclear-fuel rods assemble into bundles. Intelligent identification and positioning of these different types rods for automated bundle assembly remain a challenge owing to their extensive variations and minute distinctions. This paper presents an innovative machine-vision based nuclear-fuel rod positioning system that enables automated rod bundle assembly in a heavy-water nuclear reactor. The system is capable of identifying the type and polarity and adjusting the pose of rods by incorporating the following solutions: 1) a hypercentric imaging solution that is capable of capturing clear and complete images of the rod spacers, even for the rods with large straightness deviations; 2) a robust and noise-resistant multi-scale, multi-directional morphological edge extraction algorithm that features complete and accurate edge image extraction with minimum false edges; and 3) a rod body center at spacers deviation correction algorithm that contributes to a higher level of consistency with the true rod body center. The system is robust, as demonstrated by the following performance indices: a process capability Cpk of 1.14, which is translated into a process yield of 99.95%; 100% correct rod type identification; 100% correct rod polarity identification; and an average time of 8.92 s for positioning a single rod, meeting the required production cycle. The system has been successfully deployed in the North Nuclear Fuel Components Co., Ltd. (a subsidiary of China National Nuclear Corporation).

Design Technology for Highly Reliable Main Controller of Security Level in Nuclear Power Plants

Considering the characteristics of the main controller of the digital control system (DCS) platform of security level and its function and application, based on the specifications in relevant laws, regulations and standards, studies had been conducted on the diagnosis, redundancy, communication and embedded design of the highly reliable main controller. Key technologies such as software development were studied and applied in the design of the main control module of the China National Nuclear Corporation's DCS platform of security level, the Nuclear Advanced Safety Platform of IC the measured communication error rate was less than 10-11, meeting or even exceeding the security level DCS product specifications of other manufacturers; the hot standby redundancy architecture and embedded software meet the requirements of Class 1E equipment, ensuring the high reliability of the main controller.

General Technology Features of Reactor Core and Safety Systems Design of HPR1000

HPR1000 is an advanced pressurized water reactor developed by China National Nuclear Corporation (CNNC) with fully independent intellectual property rights. In this paper, the production process of HPR1000 are firstly introduced, and then the general technology features of reactor core and safety systems design are discussed, including reactor core neutronics design, thermal-hydraulics design, safety systems design, experiment verification and the continuously design improvement and optimization of HPR1000, etc. With the brand new advanced design philosophy and technology, the economy, flexibility and safety of HPR1000 nuclear power plant regarded as a third generation nuclear power technology are enhanced.

Developments for 230 MeV superconducting cyclotrons for proton therapy and proton irradiation

There are very strong demands for mid-energy proton machine in recent years due to the surging cancer patients and fast progress of the space science in China. For the applications of proton therapy and proton irradiation, the energy range of proton beam is usually from 200MeV to 250MeV, or even higher for astronavigation. Based on the R&D starting from 2009, a construction project of a 230MeV superconducting cyclotron (CYCIAE-230) has been launched recently at China Institute of Atomic Energy (CIAE). It was started in Jan 2015, for the program of proton therapy and space science launched by China National Nuclear Corporation (CNNC). In this paper, the designs for the superconducting (SC) cyclotron and its key components, including the main magnet, SC coils, internal ion source and central region, extraction system, etc, and the construction progress of the machine CYCIAE-230 will be presented.

Progress of Experimental Research on Nuclear Safety in NPIC

Abstract Two kinds of Generation III commercial nuclear power plants have been developed in CNNC (China National Nuclear Corporation), one is a small modular reactor ACP100 having an equivalent electric power 100 MW, and the other is HPR1000 (once named ACP1000) having an equivalent electric power 1 000 MW. Both NPPs widely adopted the design philosophy of advanced passive safety systems and considered the lessons from Fukushima Daichi nuclear accident. As the backbone of the R&amp;D of ACP100 and HPR1000, NPIC (Nuclear power Institute of China) has finished the engineering verification test of main safety systems, including passive residual heat removal experiments, reactor cavity injection experiments, hydrogen combustion experiments, and passive autocatalytic recombiner experiments. Above experimental work conducted in NPIC and further research plan of nuclear safety are introduced in this paper.

HPR1000: Advanced Pressurized Water Reactor with Active and Passive Safety

ABSTRACT HPR1000 is an advanced nuclear power plant (NPP) with the significant feature of an active and passive safety design philosophy, developed by the China National Nuclear Corporation. On one hand, it is an evolutionary design based on proven technology of the existing pressurized water reactor NPP; on the other hand, it incorporates advanced design features including a 177-fuel-assembly core loaded with CF3 fuel assemblies, active and passive safety systems, comprehensive severe accident prevention and mitigation measures, enhanced protection against external events, and improved emergency response capability. Extensive verification experiments and tests have been performed for critical innovative improvements on passive systems, the reactor core, and the main equipment. The design of HPR1000 fulfills the international utility requirements for advanced light water reactors and the latest nuclear safety requirements, and addresses the safety issues relevant to the Fukushima accident. Along with its outstanding safety and economy, HPR1000 provides an excellent and practicable solution for both domestic and international nuclear power markets.

Severe vertebra collapse due to vertebra osteonecrosis after percutaneous vertebroplasty

A 70-year-old woman complained of 2-week history of severe back pain and restricted motion after a traffic accident. A magnetic resonance imaging of the lumbar spine showed a T12 compression fracture (Figure A) and severe osteoporosis (T score: −3.4); visual analogue scale (VAS) score was 9. Bilateral percutaneous vertebroplasty was performed and a total of 4.5 mL of polymethylmethacrylate (PMMA) bone cement was injected (Figure B,C). The patient was totally free of back pain, and the VAS score was improved to be 3 at 1 week after surgery. She received risedronate sodium (5 mg/ day) and thoracolumbar hyperextension brace fixation for 1 month. However, on the 86th day after surgery, she complained of enhanced back pain without specific accident. A physical examination showed VAS score was 5, plain radiograph showed a T12 vertebra collapse and kyphoscoliosis (Figure D). Sagittal computed tomography (Figure E) and magnetic resonance imaging (Figure F) demonstrated a T12 intravertebral vacuum cleft sign, suggesting the possibility of a T12 vertebral osteonecrosis. We suggested percutaneous vertebroplasty for further treatment, but the patient refused. Wentao Wang, MD Kun Duan, MD Qu Wei, MD Qining Wu, MD Jijun Liu, MD Dingjun Hao, MD Department of Spine Surgery Hong Hui Hospital Xi’an Jiaotong University Health Science Center No. 555 East Youyi Rd, Beilin District Xi’an 710054, Shan’xi, China Department of General Surgery The 417th Hospital China National Nuclear Corporation (CNNC) No. 5 Kangfu Rd, Lintong District Xi’an 710061, Shan’xi, China

Prediction model of microwave calcining of ammonium diuranate using incremental improved back-propagation neural network

Prediction model of microwave calcining of ammonium diuranate using incremental improved back-propagation neural network Yingwei LI , Bingguo LIU , Jinhui PENG 1,2)∗, Wei LI , Daifu HUANG 3) and Libo ZHANG 1,2) 1) Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China 2) Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, China 3) No.272 Nuclear Industry Factory, China National Nuclear Corporation, Hengyang 421002, China Manuscript received 23 May 2010; in revised form 17 October 2010

The Belgian Nuclear Research Centre and the possibilities for cooperation with China

This paper gives a short overview of the activities of the Belgian Nuclear Research Centre (SCK?CEN) and the role it can play in the cooperative agreement that was established between the China National Nuclear Corporation (CNNC) and SCK?CEN. Indeed, the current established cooperation on nuclear energy research between China and Belgium should make use of the nuclear research experiences and novel activities of SCK?CEN that have accumulated over the five decades that SCK?CEN has existed. This results in a portfolio of activities that are open for cooperation with China in the fields of education and training, participation in research programmes and consultancy.

Perspective on fusion research in China: (1) efforts on nuclear fusion and plasma application in SWIP

The former Director of the Southwestern Institute of Physics, Academician Li Zengwu had suggested to the Chinese Government to promote the Nuclear Fusion Research in 1955. In the beginning of 1958, the research of nuclear fusion as future energy resources had been set up as the Fourteenth Division of China Atomic Energy Science Institute in Beijing and the Physics Institute Academy Sinica in Beijing. At the end of 1958, the East-northern Technique Physics Institute in Ha-re-bin was set up as the first institute engaged in nuclear fusion in China and then the Southwestern Institute of Physics was founded in 1965. At the beginning of this Institute, the θ-pinch, Mirror and Tokamak Research were carried on in parallel. Since 1985, the spin-off of fusion technology has been looked as an important field to make contribution to national economics and fusion effort was concentrated on Tokamak at the same time. The HL Tokamak is a general name of fusion project being carried on in Southwestern Institute of Physics, China National Nuclear Corporation. Related fusion technologies are ongoing simultaneously. The outline of HL Tokamak project and the highlights of experimental results obtained on HL-1 and HL-1M are given in this paper. In addition, the fusion efforts made important contributions to a variety of areas. Applications of fusion spin-off technologies, particularly of plasma technologies, are also described briefly in this paper.