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1. chinaXiv:202205.00171 [pdf]

IMPLEMENTATION CHALLENGES AND PROPOSED SUGGESTIONS FOR NUCLEAR MATERIAL ACCOUNTING MANAGEMENT IN SPENT FUEL REPROCESSING PLANT

何丽霞
Subjects: Nuclear Science and Technology >> Reprocessing Technology of Spent Nuclear Fuel

Nuclear material license holder should develop a nuclear material accounting management system and achieve the closed balance. According to regulations requirements, nuclear material accountancy implementation is based on  physical inventory and material measurement. Generally, the spent fuel reprocessing plant operates uninterrupted, annual throughput of  nuclear  materials  is  huge, different  measurement and analysis techniques are configured combing the reprocessing process. So the closed balance approach of nuclear materials accounting is a great challenge. In order to improve  the accuracy and reliability of nuclear material, enhance the timeliness of abnormal detection, near-real time accounting prospect of spent fuel reprocessing plant was researched. In this paper, the crucial aspect affecting the closed balance of nuclear materials was discussed, the factors such as the head-end receiver-shipper difference, the on-line process monitoring accuracy, the applicability of the international target value of nuclear material measurement uncertainty, and also the nuclear material balance model of reprocessing plants. As summarized, proposed suggestions and solutions for nuclear material balance in spent fuel reprocessing plant was put forward on the end of the paper.

submitted time 2022-05-28 Hits375Downloads170 Comment 0

2. chinaXiv:202205.00141 [pdf]

Development of an ultrafast detector and demonstration of its oscillographic application

蔡厚智,罗秋燕,林楷宣,王东,黄峻堃,刘进元
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics

A dilation X-ray detector (DIXD) based on time dilation and microchannel plate (MCP) gated technology has been reported. The DIXD passes a driving pulse along the transmission photocathode (PC) to obtain a dilated electron signal and finally achieves a high time resolution of 12 ps. Furthermore, the waveform of the PC driving pulse can be obtained using the DIXD, and a DIXD oscillographic function can be obtained. An experiment is presented to demonstrate the DIXD oscilloscope. The waveform of the PC driving pulse from points t1 to t12 is achieved by the DIXD. The waveform agrees well with that measured by a high-speed oscilloscope with a difference of less than 6%. The maximum theoretical bandwidth of the DIXD oscilloscope is theoretically studied. The bandwidth is limited by the potential difference between the PC and mesh. When the potential difference is 3.4 kV, the theoretical limiting bandwidth is 1000 GHz. The bandwidth increases with an increase in the potential difference.

submitted time 2022-05-20 Hits446Downloads233 Comment 0

3. chinaXiv:202201.00028 [pdf]

Precise calibration of cavity forward and reflected signals using low-level radio-frequency system

Ma, Jin-Ying ; Qiu, Feng ; Shi, Long-Bo ; Zhu, Zheng-Long ; Jiang, Tian-Cai ; Xue, Zong-Heng ; Jin, Ke-An ; Chen, Qi ; Xu, Cheng-Ye ; Ding, Xing-Hao ; Gao, Zheng ; Sun, Lie-Peng ; Huang, Gui-Rong ; He, Yuan
Subjects: Nuclear Science and Technology >> Particle Accelerator

Precise measurements of the cavity forward (Vf) and reflected signals (Vr) are essential for characterizing other key parameters such as the cavity detuning and forward power. In practice, it is challenging to measure Vf and Vr precisely because of crosstalk between the forward and reflected channels (e.g., coupling between the cavity reflected and forward signals in a directional coupler with limited directivity). For DESY, a method based on the cavity differential equation was proposed to precisely calibrate the actual Vf and Vr. In this study, we verified the validity and practicability of this approach for the Chinese ADS front-end demo superconducting linac (CAFe) facility at the Institute of Modern Physics and a compact energy recovery linac (cERL) test ma#2;chine at KEK. At the CAFe facility, we successfully calibrated the actual Vf signal using this method. The result demonstrated that the directivity of directional couplers might seriously affect the accuracy of Vf measurement. At the cERL facility, we calibrated the Lorentz force detuning (LFD) using the actual Vf. Our study confirmed that the precise calibration of Vf significantly improves the accuracy of the cavity LFD measurement.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1207Downloads331 Comment 0

4. chinaXiv:202201.00027 [pdf]

Calibrating the linearity between grayscale and element content for X-ray KES imaging of alloys

Ju, Xiao-Lu ; Deng, Biao ; Li, Ke ; Yu, Fu-Cheng ; Zhang, Hai-Peng ; Xu, Ming-Wei ; Du, Guo-Hao ; Xie, Hong-Lan ; Li, Bin ; Xiao, Ti-Qiao
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology

Doped elements in alloys significantly impact their performance. Conventional methods usually sputter the surface material of the sample, or their performance is limited to the surface of alloys owing to their poor penetration ability. The X-ray K-edge subtraction (KES) method exhibits great potential for the nondestructive in situ detection of element contents in alloys. However, the signal of doped elements usually deteriorates because of the strong absorption of the principal component and scattering of crystal grains. This in turn prevents the extensive application of X-ray KES imaging to alloys. In this study, methods were developed to calibrate the linearity between the grayscale of the KES image and element content. The methods were aimed at the sensitive analysis of elements in alloys. Furthermore, experiments with phantoms and alloys demonstrated that, after elaborate calibration, X-ray KES imaging is capable of nondestructive and sensitive analysis of doped elements in alloys.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1244Downloads376 Comment 0

5. chinaXiv:202201.00019 [pdf]

Studies of the radiation environment on the Mars surface using the Geant4 toolkit

Chen, Jun-Liang ; Yun, Su-Jun ; Dong, Tie-Kuang ; Ren, Zhong-Zhou ; Zhang, Xiao-Ping
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology

The radiation environment on the surface of Mars is a potential threat for future manned exploration missions to this planet. In this study, a simple geometrical model was built for simulating the radiation environment on the Mars surface caused by galactic cosmic rays (GCRs); the model was built and studied using the Geant4 toolkit. The simulation results were compared with the data reported by a radiation assessment detector (RAD).

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1124Downloads346 Comment 0

6. chinaXiv:202201.00018 [pdf]

Improved formation density measurement using controllable D-D neutron source and its lithological correction for porosity prediction

Zhang, Li ; Yu, Hua-Wei ; Li, Yang ; Jia, Wen-Bao ; Han, Xiao ; Geng, Xue-Sen
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology

Controllable D-D neutron sources have a long service life, low cost, and non-radioactivity. There are favorable prospects for its application in geophysical well logging, since traditional chemical radioactive sources used for well logging pose potential threats to the safety of the human body and environment. This paper presents an improved method to measure formation density that employs a D-D neutron source. In addition, the lithological effect on the measured density was removed to better estimate the formation porosity. First, we investigated the spatial distribution of capture gamma rays through Monte Carlo simulations as well as the relationship between the ratio of capture gamma ray counts and formation density to establish theoretical support for the design of density logging tools and their corresponding data processing methods. Second, we obtained the far to near detector counts of captured gamma rays for an optimized tool structure, and then established its correlation with the density and porosity of three typical formations with pure quartz, calcite, and dolomite minerals. Third, we determined the values for correcting the densities of sandstone and dolomite with the same porosity using limestone data as the reference and established the equations for calculating the correction values, which lays a solid foundation for accurately calculating formation porosity. We observed that the capture gamma ray counts first increased then decreased and varied in different formations; this was especially observed in high-porosity formations. Under the same lithologic conditions (rock matrix), as the porosity increases, the peak value of gamma ray counts moves toward the neutron source. At different detector-source distances, the ratio of the capture gamma ray counts was well correlated with the formation density. An equation of the formation density conversion was established based on the ratio of capture gamma ray counts at the detector-source distances of 30 cm and 65 cm, and the calculated values were consistent with the true values. After correction, the formation density was highly consistent with the true value of the limestone density, and the mean absolute error was -0.013 g/cm3. The calculated porosity values were very close to the true values, and the mean relative error was 2.33%, highlighting the accuracy of the proposed method. These findings provide a new method for developing D-D neutron source logging tools and their well-log data processing methods.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1303Downloads411 Comment 0

7. chinaXiv:202201.00017 [pdf]

A novel 4D resolution imaging method for low and medium atomic number objects at the centimeter scale by coincidence detection technique of cosmic-ray muon and its secondary particles

Ji, Xuan-Tao ; Luo, Si-Yuan ; Huang, Yu-He ; Zhu, Kun ; Jin, Zhu ; Peng, Xiao-Yu ; Xiao, Min; Wang, Xiao-Dong
Subjects: Nuclear Science and Technology >> Radiation Physics and Technology

The muon radiography imaging technique for high-atomic-number objects (Z) and large-volume objects via muon transmission imaging and muon multiple scattering imaging remains a popular topic in the field of radiation detection imaging. However, few imaging studies have been reported on low and medium Z objects at the centimeter scale. This paper presents an imaging system that consists of three layers of a position-sensitive detector and four plastic scintillation detectors. It acquires data by coincidence detection technique of cosmic-ray muon and its secondary particles. A 3D imaging algorithm based on the density of the coinciding muon trajectory was developed, and 4D imaging that takes the atomic number dimension into account by considering the secondary particle ratio information was achieved. The resultant reconstructed 3D images could distinguish between a series of cubes with 5-mm side lengths and 2-mm intervals. If the imaging time is more than 20 days, this method can distinguish intervals with a width of 1 mm. The 4D images can specify target objects with low, medium, and high Z values.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1165Downloads388 Comment 0

8. chinaXiv:202201.00016 [pdf]

Commissioning of a high-resolution collinear laser spectroscopy apparatus with a laser ablation ion source

Bai, Shi-Wei; Yang, Xiao-Fei ; Wang, Shu-Jing ; Liu, Yong-Chao ; Zhang, Peng ; Liu, Yin-Shen ; Hu, Han-Rui ; Guo, Yang-Fan ; Wang, Jin ; Du, Ze-Yu ; Yan, Zhou ; Zhang, Yun-Kai; Ye, Yan-Lin ; Li, Qi-Te ; Ge, Yu-Cheng ; He, Chuang-Ye
Subjects: Nuclear Science and Technology >> Particle Accelerator

Collinear laser spectroscopy is a powerful tool for studying the nuclear spins, electromagnetic moments, and charge radii of exotic nuclei. To study the nuclear properties of unstable nuclei at the Beijing Radioactive Ion#2;beam Facility (BRIF) and the future High Intensity Heavy-ion Accelerator Facility (HIAF), we developed a collinear laser spectroscopy apparatus integrated with an offline laser ablation ion source and a laser system. The overall performance of this state-of-the-art technique was evaluated and the system was commissioned using a bunched stable ion beam. The high-resolution optical spectra for the 4s 2S1/2 → 4p 2P3/2 (D2) ionic transition of 40,42,44,48Ca isotopes were successfully measured. The extracted isotope shifts relative to 40Ca showed excellent agreement with the literature values. This system is now ready for use at radioactive ion beam facilities such as the BRIF and paves the way for the further development of higher-sensitivity collinear resonant ionization spectroscopy techniques.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1112Downloads344 Comment 0

9. chinaXiv:202201.00015 [pdf]

Performance of the CENDL-3.2 and other major neutron data libraries for criticality calculations

Zhang, Bin; Ma, Xu-Bo ; Hu, Kui ; Zhang, Teng ; Ma, Xuan ; Chen, Yi-Xue
Subjects: Nuclear Science and Technology >> Engineering Technology of Fission Reactor

Nuclear data are the cornerstones of reactor physics and shielding calculations. Recently, China released CENDL-3.2 in 2020, and the United States released ENDF/B-VIII.0 in 2018. Therefore, it is necessary to comprehensively evaluate the criticality computing performance of these newly released evaluated nuclear libraries. In this study, we used the NJOY2016 code to generate ACE format libraries based on the latest neutron data libraries (including CENDL-3.2, JEFF3.3, ENDF/B-VIII.0, and JENDL4.0). The MCNP code was used to conduct a detailed analysis of fission nuclides, including 235U, 233U, and 239Pu, in different evaluated nuclear data libraries based on 100 benchmarks. The criticality calculation performance of each library was evaluated using three statistical parameters: , , and . Analysis of the parameter showed that CENDL-3.1 and JENDL-4.0 both had >10 benchmarks that exceeded 3σ, whereas CENDL-3.2, ENDFB-VIII.0, and JEFF-3.3 had, 7, 5, and 4 benchmarks, respectively, exceeding 3σ. The ENDF/B-VII.1 library performed best, with only two benchmarks exceeding 3σ. Compared with CENDL-3.1, CENDL-3.2 offers an improvement in criticality calculations. Compared with the JEFF-3.3 and ENDF/B-VIII.0 libraries, CENDL3.2 performs better in the calculation of the 233U assemblies, but it performs poorly in the pusl11 series case calculation of the 239Pu assemblies, and thus further improvement is needed.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1126Downloads352 Comment 0

10. chinaXiv:202201.00014 [pdf]

Application of homogenization techniques for inflow transport approximation on light water reactor analysis

Xiao, Xiang ; Wang, Kan ; Yang, Tong-Rui ; Chen, Yi-Xue
Subjects: Nuclear Science and Technology >> Engineering Technology of Fission Reactor

The transport cross-section based on inflow transport approximation can significantly improve the accuracy of light water reactor (LWR) analysis, especially for the treatment of the anisotropic scattering effect. The previous inflow transport approximation is based on the moderator cross-section and normalized fission source, which is approximated using transport theory. Although the accuracy of reactivity is increased, the P0 flux moment has a large error in the Monte Carlo code. In this study, an improved inflow transport approximation was introduced with homogenization techniques, applying the homogenized cross-section and accurate fission source. The numerical results indicated that the improved inflow transport approximation can increase the P0 flux moment accuracy and maintain the reactivity calculation precision with the previous inflow transport approximation in typical LWR cases. In addition to this investigation, the improved inflow transport approximation is related to the temperature factors. The improved inflow transport approximation is flexible and accurate in the treatment of the anisotropic scattering effect, which can be directly used in the temperature-dependent nuclear data library.

submitted time 2021-12-31 Cooperative journals:《Nuclear Science and Techniques》 Hits1160Downloads400 Comment 0

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