State Nuclear Security Technology Center

Beijing, China

State Nuclear Security Technology Center

Beijing, China
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Han Y.L.,State Nuclear Security Technology Center | Ma W.,National Quality Inspection and Testing Center for Surveying and Mapping Products
Information Technology and Computer Application Engineering - Proceedings of the 2013 International Conference on Information Technology and Computer Application Engineering, ITCAE 2013 | Year: 2014

The research on the forecast of social security incidents covers many subjects such as social science, mathematics and computer science. This paper proposes dividing forecasting and pre-warning of social security incidents into two parts: macroscopic forecast and microscopic forecast, mainly comprehensively reviews the macroscopic forecast method and systemically generalizes several forecast methods such as: Time series analysis; regression analysis and data mining technique, etc. The paper also generalizes the application scope, advantages as well as disadvantages of various methods and indicates the research direction and hot spot of this field by combining the features of various types of social security incidents based on the analysis of the mathematical characteristics of each method. © 2014 Taylor & Francis Group, London.


Zhang N.,CAS Beijing National Laboratory for Molecular | Liu X.,CAS Beijing National Laboratory for Molecular | Li C.,CAS Beijing National Laboratory for Molecular | Li C.,State Nuclear Security Technology Center | Liu C.,CAS Beijing National Laboratory for Molecular
Inorganic Chemistry Frontiers | Year: 2015

Molecular dynamics (MD) simulations of uranyl species adsorption in montmorillonite pores in 0, 0.05 and 0.10 M NaCl were carried out to investigate the influence of internal electrolyte concentration on the uptake amount, species distribution and electrical double-layer (EDL) structures. Most cases revealed that the β- and d-planes of the adsorbates are located 4.3-4.6 Å and 5.5-5.8 Å from the clay planes, respectively. However, based on the split carbonate peaks, an exception, the left peaks near the clay surface for 0.10 M NaCl, formed more uranyl-(bi)carbonate complexes than the other peaks. Under this condition, each peak and minimum of cations shifted slightly farther away from the clay plane. For this outlying case, the charge density profile confirmed the charge inversion of carbonates near like-charged surfaces. Collectively, the simulations revealed the subtle influence of the internal NaCl concentration (0-0.05 M) on the EDL structure, uptake amount and species distribution. In particular, a threshold concentration (0.10 M NaCl in this study) for charge inversion within the β-plane may exist. Under this condition, a pronounced change in the EDL structure occurs, which in turn causes a dramatic alteration in the uranyl species adsorption relative to lower electrolyte concentrations. © the Partner Organisations 2015.


News Article | March 18, 2016
Site: www.reuters.com

Residents on their bicycles and electric bikes wait for the traffic at an intersection amid heavy smog in Shijiazhuang, Hebei province, China, December 10, 2015. Picture taken December 10, 2015. A researcher works at impurity analysis laboratory of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. A researcher works at unattended and remote monitoring laboratory of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. Researchers are seen behind water drops on a glass wall at water test laboratory of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. A researcher walks past the Digital Cerenkov Viewing Device at the analytical laboratory of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. A researcher works at y-Ray analysis laboratory of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. A researcher works at a laboratory to analyze samples containing low levels of fissionable isotopes at the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. Workers demonstrate a perimeter intrusion detection and assessment system at the exhibition hall of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. A security guard stands in front of the gate of the Center of Excellence on Nuclear Security in the State Nuclear Security Technology Center in Beijing, China, March 18, 2016. Hebei is home to seven of China's ten smoggiest cities. Under pressure to use cleaner energy sources, the province has already pledged to cut its consumption of polluting coal by 40 million tonnes over 2013-2017. "For the integrated development of the Beijing-Tianjin-Hebei region, we are currently planning to build a nuclear plant on the Hebei coast," Xu Dazhe, chairman of the China Atomic Energy Authority, said at the launch of a China-U.S. nuclear safety research facility on the outskirts of Beijing. He said the smog that had descended on Beijing this week was a reminder of the need to develop nuclear energy, which is also set to play a big role in meeting China's pledge to bring its greenhouse gas emissions to a peak by around 2030. One of China's biggest state reactor builders has said the country's total installed nuclear capacity could rise to 120-150 gigawatts (GW) by 2030 from 28.3 GW in 2015. The increase would require the completion of 8-10 new reactors every year until the end of the next decade. With all the country's existing reactors clustered in coastal regions, Xu said China continued to look into the possibility of building plants in the interior, adding that safety was the priority. China has never experienced a serious nuclear accident, but it acknowledges its regulatory and emergency response capabilities remain insufficient. It is currently drawing up new atomic energy and nuclear safety laws and training up hundreds of staff in order to meet the gap. Xu said the challenges remain huge but that the central government has already invested "billions of yuan" to boost security at existing plants. Among new projects, China is focusing on safer "third-generation" reactor designs, including its homegrown Hualong 1 technology that will be promoted overseas in line with Beijing efforts to become a globally dominant player in the sector. Chinese president Xi Jinping will join global leaders in Washington at the end of March to discuss issues such as nuclear proliferation and terrorism at an annual global security summit. "I am very confident that President Xi and President Obama are going to talk about the appetite that both of our countries have to continue our cooperation," said U.S. energy secretary Moniz, who attended the ceremony to launch the China Center of Excellence on Nuclear Security in Beijing on Friday. The China-U.S. facility will conduct research and share best practices on issues like securing hazardous nuclear materials and protecting reactors from attacks.


Han Y.,State Nuclear Security Technology Center | Davidson R.A.,University of Delaware | Black G.,AECOM Technology Corporation | Pei S.,South Dakota State University
Structural Safety | Year: 2013

In this paper, we examine issues related to the definition of seismic performance objectives at a regional scale. Specifically, we introduce a new regional seismic loss model for woodframe buildings and a building variant selection method that identifies a specific design for each building in a region based on stated performance objective policy guidelines. We then present full-scale applications of these methods for the city of Los Angeles, and examine how such analyses can inform a deliberative, public decision making process about what might constitute appropriate, achievable regional performance goals. The results suggest that for woodframe buildings, efforts to define performance policies at a regional scale should consider the empirical limits of what is reasonably achievable and how those vary by building type and location. Empirical and analytical analyses also indicate that targeting individual building loss performance does not necessarily guarantee the same level of regional loss performance. Further, at smaller target loss levels, the achieved regional loss may not be conservative in that the return period is smaller than in the targeted individual performance objective. While the empirical results presented apply only to woodframe buildings in Los Angeles, the general approach to examining performance policies at a regional scale could be applied to other structural types or regions. We introduce a new regional seismic loss model for woodframe buildings. We introduce a building design selection method. Regional performance policies must consider empirical limits of what is achievable. Individual building loss performance does not guarantee same regional performance. Achieved regional loss performance may not be conservative. © 2013 Elsevier Ltd.


Liu X.-Y.,CAS Beijing National Laboratory for Molecular | Wang L.-H.,CAS Beijing National Laboratory for Molecular | Zheng Z.,CAS Beijing National Laboratory for Molecular | Kang M.-L.,CAS Beijing National Laboratory for Molecular | And 3 more authors.
Journal of Hazardous Materials | Year: 2013

Molecular dynamics simulations were carried out to investigate the diffusive behavior of aqueous uranium species in montmorillonite pores. Three uranium species (UO2 2+, UO2CO3, UO2(CO3)2 2-) were confirmed in both the adsorbed and diffuse layers. UO2(CO3)3 4- was neglected in the subsequent analysis due to its scare occurrence. The species-based diffusion coefficients in montmorillonite pores were then calculated, and compared with the water mobility and their diffusivity in aqueous solution/feldspar nanosized fractures. Three factors were considered that affected the diffusive behavior of the uranium species: the mobility of water, the self-diffusion coefficient of the aqueous species, and the electrostatic forces between the negatively charged surface and charged molecules. The mobility of U species in the adsorbed layer decreased in the following sequence: UO2 2+>UO2CO3>UO2(CO3)2 2-. In the diffuse layer, we obtained the highest diffusion coefficient for UO2(CO3)2 2- with the value of 5.48×10-10m2s-1, which was faster than UO2 2+. For these two charged species, the influence of electrostatic forces on the diffusion of solutes in the diffuse layer is overwhelming, whereas the influence of self-diffusion and water mobility is minor. Our study demonstrated that the negatively charged uranyl carbonate complex must be addressed in the safety assessment of potential radioactive waste disposal systems. © 2012 Elsevier B.V.


Wang C.,CAS Beijing National Laboratory for Molecular | Yang X.,CAS Beijing National Laboratory for Molecular | Li C.,CAS Beijing National Laboratory for Molecular | Li C.,State Nuclear Security Technology Center | Liu C.,CAS Beijing National Laboratory for Molecular
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2015

To explore the sorption phenomenon and mechanism between humic acid (HA) and Beishan granite (BsG), the influence of factors such as pH, contact time, ionic strength, temperature, HA concentration and solid-to-liquid ratio were investigated using the batch technique. The sorption process was significantly affected by pH and ionic strength. The maximum adsorption capacity of HA on BsG was approximately 0.9493mgg-1 at pH=6.7 and T=305K, and the thermodynamic parameters indicated that the sorption process was spontaneous and endothermic. The SEM-EDS results indicated the presence of a certain amount of HA on BsG after sorption with HA. The results of FT-IR spectroscopy and the change in pH demonstrated that ligand exchange-surface complexation may be an important mechanism. BET analysis showed that parts of the HA tended to enter the pores formed by close-packing of BsG particles, and albite and muscovite might have played a role in the sorption process, as indicated by the XRD analysis. Overall, it is speculated that the mechanisms governing the sorption behaviors of HA on BsG are precipitation, ligand exchange-surface complexation and electrostatic interaction. Moreover, the colloidal properties of HA under certain conditions may also significantly affect its sorption interactions with BsG. © 2015 Elsevier B.V.


Li B.-P.,Beijing Research Institute of Uranium Geology | Liu L.-K.,State Nuclear Security Technology Center | Hao W.-L.,Beijing Research Institute of Uranium Geology | Chang Y.,Beijing Research Institute of Uranium Geology | And 2 more authors.
He-Huaxue yu Fangshe Huaxue/Journal of Nuclear and Radiochemistry | Year: 2014

A matrix pre-separation method for the determination of uranium content and 234U/238U activity ratios in saline waters by ICP-MS and α-spectrometry was studied. The uranium was well pre-separated from saline waters by Chelex-100 resin. The separation efficiency of Na is higher than 99.9%. The recovery of uranium is in the range of 90.5%-106% with sr<10% (n=4). The 234U/238U activity ratios were achieved by α-spectrometry after removing the interferences by P350 resin. The results show that the matrix pre-removal method can be well adapted to determine 234U/238U activity ratios in saline waters. The sr of 3 times determination is less than 5%. The developed method has been already applied to determine the uranium content and 234U/238U activity ratios in real saline waters.

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