Hsingtzu's lab is recruiting undergraduate and graduate students interested in the following research areas:
Multiphysics analysis for Small Modular Reactors (SMRs).
Natural circulation in advanced reactors and SMRs, including experiments and CFD computations.
Preparation for potential nuclear accidents, focusing on safety analysis and system behavior.
Energy efficiency of household refrigeration, exploring the relationship between usage behavior, cooling capacity, and power consumption.
Start dates are flexible, with openings available beginning Fall 2025 and beyond. Applications from students with varying levels of experience are welcome. A stipend may be offered based on performance.
To apply, please send your CV/resume and academic transcript(s) (undergraduate and, if applicable, graduate) to hsingtzu@mx.nthu.edu.tw
Shortlisted applicants will be invited for an interview to discuss research interests, potential fit with the lab, and opportunities for academic and professional growth.
We quantitatively investigated face mask materials’ ability to block radioactive alpha and beta radiation. The results suggest that wearing a relatively thick polyester or N95 mask may be a better choice than wearing a thin nonwoven mask to prevent inhaling alpha and beta particles during a radiation emergency.
Hsingtzu Wu*, Hong-Da Liu, Tzu-Hsiang Lin, Ming-Wei Lin, Measurements of Face Mask’s Capability to Block Ionizing Radiation, Scientific Reports, Volume 15, 2025, 6516. https://doi.org/10.1038/s41598-025-89643-4
The adventure started at the University of Illinois at Urbana-Champaign, where I was allowed to decide the subject of my Ph.D. study. I decided to test a new idea of coupling neutronics and thermal-hydraulics after taking courses in neutronics, thermal-hydraulics, and programming. I named the new idea Integrated Tight Coupling, or ITC, which modified the equations instead of solving the same equations with different approaches as the traditional loose coupling and tight coupling do. Implementing ITC is similar to loose coupling, but primary results suggest that ITC allows a coarser mesh and fewer iterations [01]. During my Ph.D. period, I completed an internship at Idaho National Laboratory. I added and validated new features and models to a code that predicts hydrogen distribution inside a containment. Results of the 12-week work are published in Annals of Nuclear Energy [02].
References
[01] Hsingtzu Wu, Rizwan-uddin, “A Tightly Coupled Scheme for Neutronics and Thermal-hydraulics using Open-source Software,” Annals of Nuclear Energy. Vol. 87, January 2016, pages 16-22. https://doi.org/10.1016/j.anucene.2015.08.004
[02] Hsingtzu Wu, Haihua Zhao, “Validation of hydrogen gas stratification and mixing models,” Annals of Nuclear Energy. Vol. 85, November 2015, pages 137-144. https://doi.org/10.1016/j.anucene.2015.05.003
After graduation, I wanted to learn more about the Fukushima accident and do something for it, so I joined the Japan Atomic Energy Agency (JAEA) as a postdoctoral scholar. I collaborated with the researchers to gain insights into fuel behavior during LOCA experimentally and computationally. I scrutinized experimental data and found that the mechanical behavior of cladding was affected by its thermal diffusivity, thermal expansion, and oxygen dissolved in the metallic layer, which had not been considered in the analysis. Therefore, I derived equations using published data, and the updated code gave better predictions [03].
In addition, I designed experiments to reveal the order of cracks formed in cladding during LOCA quench conditions using different thermal stresses, which was achieved economically by different thermal capacities inside the cladding. High thermal stress resulted in cracks in the oxide, while low thermal stress did not. It suggests that the cracks form in the αZr(O) layer first, then in the oxide, and finally in the prior-β layer when the fracture of cladding occurs [04]. I visited Helmholtz-Zentrum Dresden-Rossendorf (HZDR) after the end of the work contract in Japan. I successfully developed an interface to couple DYN3D (the in-house neutronic code of HZDR) and OpenFOAM. I verified it with a 3-D reactor model with the help of my supervisors in three months [05].
References
[03] Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, and Masaki Amaya, “Validation of updated RANNS with effect of oxygen-dissolved metallic Zircaloy-4 under LOCA quench condition,” Nuclear Engineering and Design, Vol. 300, 15 April 2016, Pages 249-255. https://doi.org/10.1016/j.nucengdes.2016.01.032
[04] Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, and Masaki Amaya, “Crack formation in cladding under LOCA quench conditions,” Nuclear Engineering and Design, Vol. 303, July 2016, Pages 25-30. https://doi.org/10.1016/j.nucengdes.2016.03.033
[05] Hsingtzu Wu, Alexander Grahn and Soeren Kliem, “Verification of a coupling interface for DYN3D and OpenFOAM with a three-dimensional mini-core,” Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020, a virtual meeting, May 18-22, 2020.
Then, I was attracted by the aggressive nuclear power program in China. I thought that people around the world would suffer if something went wrong with a nuclear power plant in China, and therefore, it would be meaningful to work on nuclear safety in China. I led an independent research group that focused on nuclear safety. The study was guided by the idea that the development of nuclear power would be mainly affected by two factors. One is the price of nuclear energy, and the other is the public perception of nuclear safety. Therefore, we explored three economical ways to enhance nuclear safety.
First, I studied the concept of a passive residual heat removal heat exchanger (HX) and proposed changing the configuration of C-shaped HX tubes to spiral-shaped ones. The CFD computation suggests that the new design enhances heat transfer and increases cooling capacity [06]. In addition, I noticed that none had examined the effect of tube defects on the performance of the HX, so we did it. The computational results suggest that it is correlated with the size of the surface area of the deficient tubes instead of their locations [07].
Second, I was inspired by moisture spikes on the lid of a Staub cookware that were designed to create a rainforest effect and return juices evenly to the food. I proposed placing moisture spikes on the dome of the containment to enhance water circulation during an emergency. We tested two designs—spherical and conical spikes—and the computational results suggest that the former has a better heat transfer performance [08]. A spherical spike improves the heat transfer rate by 11.7%. The spiral-shaped heat exchanger tubes and moisture spikes have the potential to be implemented in any nuclear power plant without much cost.
Third, the nuclear industry has spent lots of effort in enhancing nuclear safety, but many people still claim that nuclear is dangerous. A better understanding of people’s perceptions might be helpful in gaining support. Using behavioral economics concepts, we conducted surveys to gain insights into young Chinese people’s opinions on nuclear power. The analyses suggest that young Chinese people’s perceptions of radiation significantly impacted their views on nuclear power. In addition, perceptions of nuclear reactor technology seemed independent of their perceptions of nuclear power, which were not the main factor influencing the respondents’ support for nuclear power [09-10]. In other words, either boasting about advanced reactor technology or working on people’s perception of nuclear power would not gain support for nuclear power efficiently. The key is how people think about radiation.
References
[06] Hsingtzu Wu, Linfeng Yan, Lanshan Yuan, “Pilot numerical study of new design of passive residual heat removal heat exchanger tubes,” Progress in Nuclear Energy, Volume 146, 2022, 104150. https://doi.org/10.1016/j.pnucene.2022.104150
[07] Linfeng Yan, Dawei Wang, Hsingtzu Wu, “Analysis of Influence of Tube Failure on Performance of Passive Residual Heat Removal Heat Exchanger,” Nuclear Technology, Volume 208, Issue 12, 2022, 1822-1831. https://doi.org/10.1080/00295450.2022.2083750
[08] Li Zhou, Hsingtzu Wu, “A pilot study on modification of containment dome surface to enhance condensation,” Progress in Nuclear Energy, Volume 156, 2023, 104557. https://doi.org/10.1016/j.pnucene.2022.104557
[09] Hsingtzu Wu, Leyao Huang, “Young Chinese people's radiological beliefs significantly associated with their opinions on nuclear power,” Progress in Nuclear Energy, 138, 2021, 103797. https://doi.org/10.1016/j.pnucene.2021.103797
[10] Hsingtzu Wu, Leyao Huang, Lanshan Yuan, Da-Wei Wang, Shaoxuan Wang, “Young Chinese people's perceptions of nuclear power: Connection with enthusiasm for information, perceptions of nuclear reactor technology and NIMBY,” Progress in Nuclear Energy, Volume 141, 2021, 103964. https://doi.org/10.1016/j.pnucene.2021.103964
In addition to nuclear power, I proposed new ideas in areas including irradiation and renewable energy. After visiting a gamma irradiator, I came up with a new configuration of a shuffle-dwell gamma irradiator based on the fact that radiation emits in an isotropic fashion. Compared to the current configuration, the proposed one has the potential to increase energy utilization and throughput, which leads to higher profitability [11]. I attended a seminar and learned that forecasting models of renewable energy were evaluated statistically. I proposed evaluating these models from the perspectives of the power grid's stability and usable energy availability [12]. I like to think about new ideas to improve the performance of current systems and treat problems holistically.
References
[11] Hsingtzu Wu, “A proposed new configuration of a shuffle-dwell gamma irradiator,” Nuclear Engineering and Technology, Volume 54, Issue 8, 2022, Pages 3176-3180. https://doi.org/10.1016/j.net.2022.03.007
[12] Hsingtzu Wu, Da-Wei Wang, “A New Method to Compare Performance of Forecasting Models,” proceedings of 2021 IEEE 5th Conference on Energy Internet and Energy System Integration (EI2), 2021, pp. 1320-1325, doi: 10.1109/EI252483.2021.9713024. https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9713024
16. Hsingtzu Wu*, Hong-Da Liu, Tzu-Hsiang Lin, Ming-Wei Lin, Measurements of Face Mask’s Capability to Block Ionizing Radiation, Scientific Reports, Volume 15, 2025, 6516. https://doi.org/10.1038/s41598-025-89643-4
15. Linfeng Yan, Dawei Wang, Hsingtzu Wu*, Numerical study on the influence of input power and tube shape on a single-phase natural circulation for passive residual heat removal heat exchanger, Progress in Nuclear Energy, Volume 159, 2023, 104643.
14. Hsingtzu Wu*, Dawei Wang, Pilot study of response-order effects on survey on young Chinese's perceptions of nuclear power, Progress in Nuclear Energy, Volume 157, 2023, 104587.
13. Li Zhou, Hsingtzu Wu*, A pilot study on modification of containment dome surface to enhance condensation, Progress in Nuclear Energy, Volume 156, 2023, 104557.
12. Linfeng Yan, Dawei Wang, Hsingtzu Wu*, Analysis of Influence of Tube Failure on Performance of Passive Residual Heat Removal Heat Exchanger, Nuclear Technology, Volume 208, Issue 12, 2022, pages 1822-1831.
11. Hsingtzu Wu*, A proposed new configuration of a shuffle-dwell gamma irradiator, Nuclear Engineering and Technology, Volume 54, Issue 8, 2022, Pages 3176-3180.
10. Hsingtzu Wu*, Linfeng Yan, Lanshan Yuan, Pilot numerical study of new design of passive residual heat removal heat exchanger tubes, Progress in Nuclear Energy, Volume 146, 2022, 104150.
09. Hsingtzu Wu*, Leyao Huang, Lanshan Yuan, Da-Wei Wang, Shaoxuan Wang, Young Chinese people's perceptions of nuclear power: Connection with enthusiasm for information, perceptions of nuclear reactor technology and NIMBY, Progress in Nuclear Energy, Volume 141, 2021, 103964.
08. Hsingtzu Wu*, Leyao Huang, Young Chinese people's radiological beliefs significantly associated with their opinions on nuclear power, Progress in Nuclear Energy, 138, 2021, 103797.
08a. Hsingtzu Wu*, Leyao Huang, Corrigendum to Young Chinese people's radiological beliefs significantly associated with their opinions on nuclear power [Prog. Nucl. Energy 138 (2021) 103797], Progress in Nuclear Energy, Volume 139, 2021, 103934.
07. Hsingtzu Wu*, Experience of teaching gas-liquid two-phase flow using PBL pedagogy, Research in Higher Education of Engineering, 2019, 80-81 (in Chinese).
06. Yang Jun, Zhu Donglai, Wu Hsingtzu, Wang Beiqi, Xu Lejin. Hot spots of nuclear energy science and technology in 2018. Science & Technology Review, 2019, 37(1): 121-133. (in Chinese).
05. Yang Jun, Yang Zhangcan, Xu Lejin, Wu Hsingtzu, Deng Chengcheng, Zhou Xiafeng, Hu Bangda, Hot spots of nuclear energy science and technology in 2017, Science & Technology Review, 2018, 36(1) pages 31-45. (in Chinese).
04. Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, Masaki Amaya, Crack formation in cladding under LOCA quench conditions, Nuclear Engineering and Design, Vol. 303, July 2016, Pages 25-30.
03. Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, Masaki Amaya, Validation of updated RANNS with effect of oxygen-dissolved metallic Zircaloy-4 under LOCA quench condition, Nuclear Engineering and Design, Vol. 300, 15 April 2016, Pages 249-255.
02. Hsingtzu Wu*, Rizwan-uddin, A Tightly Coupled Scheme for Neutronics and Thermal-hydraulics using Open-source Software, Annals of Nuclear Energy. Vol. 87, January 2016, pages 16-22.
01. Hsingtzu Wu, Haihua Zhao, Validation of hydrogen gas stratification and mixing models, Annals of Nuclear Energy. Vol. 85, November 2015, pages 137-144.
29. Li Zhou, Hsingtzu Wu, Dawei Wang, Pilot Numerical Study of Proposed Modification of the Surface of the Containment Dome to Enhance Condensation, proceedings of the 13th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS 13), a virtual conference, September 6-8, 2022.
28. Linfeng Yan, Dawei Wang, Hsingtzu Wu, Sensitivity Analysis of Spiral Tube for Passive Residual Heat Removal Heat Exchanger, proceedings of the 13th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS 13), a virtual conference, September 6-8, 2022.
27. Hsingtzu Wu, A Small-scale Survey on Students’ Opinions on Online Teaching Methods, proceedings of 2022 National School of Energy and Power Reform of Teaching Methods Conference, Chongqing, China, November 4-6, 2022 (in Chinese).
26. Hsingtzu Wu, Li Zhou, Experiment and Animation to Teach the Concept of Turbulent and Laminar Flows, proceedings of 2022 National School of Energy and Power Reform of Teaching Methods Conference, Chongqing, China, November 4-6, 2022 (in Chinese).
25. Hsingtzu Wu, Da-Wei Wang, A New Method to Compare Performance of Forecasting Models, proceedings of 2021 IEEE 5th Conference on Energy Internet and Energy System Integration (EI2), 2021, pp. 1320-1325, doi: 10.1109/EI252483.2021.9713024.
24. Hsingtzu Wu, Leyao Huang, Chinese Public May Have a Different Perception of Severe Nuclear Accidents, Proceedings of the 2021 28th International Conference on Nuclear Engineering. Volume 3: Computational Fluid Dynamics (CFD); Verification and Validation; Advanced Methods of Manufacturing (AMM) for Nuclear Reactors and Components; Decontamination, Decommissioning, and Radioactive Waste Management; Beyond Design Basis and Nuclear Safety; Risk Informed Management and Regulation. Virtual, Online. August 4–6, 2021. V003T13A010. ASME. https://doi.org/10.1115/ICONE28-65349
23. Hsingtzu Wu, Chinese Students’ Feedback about Online Nuclear Engineering Courses, Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2021), a virtual meeting, Feb 8-11, 2021. Pages 93-94.
22. Hsingtzu Wu, Shaoxuan Wang, Proposition of a natural radiation shielding outside the containment of a nuclear power plant, Annual meeting of Chinese radiation protection society, Guangzhou, China, Dec 2-6, 2020 (in Chinese).
21. Hsingtzu Wu, A Proposed New Configuration of a Shuffle-dwell Gamma Irradiator, proceeding of 2020 ANS Virtual Winter meeting, Nov 15-19, 2020.
20. Linfeng Yan, Hsingtzu Wu, Analysis of Heat Transfer and Sensitivity on Shell Side of Natural Circulation Heat Exchanger, proceeding of annual meeting of CNNC thermal-hydraulic laboratory, Chengdu, Sichuan, Nov 3-6, 2020 (in Chinese).
19. Linfeng Yan, Hsingtzu Wu, Reducing initial temperature of IRWST improves performance of passive residual heat removal heat exchanger, proceeding of 2020 Chinese nuclear society mid-west conference, Taiyuan, Jiangxi, Oct 28-31, 2020 (in Chinese).
18. Hsingtzu Wu, Da-Wei Wang, Analysis of Chinese people’s perception of radiation and nuclear power with insights into behavioral science, proceedings of the 2020 International Conference on Nuclear Engineering collocated with the ASME 2020 Power Conference. Volume 2: Nuclear Policy; Nuclear Safety, Security, and Cyber Security; Operating Plant Experience; Probabilistic Risk Assessments; SMR and Advanced Reactors. Virtual, Online., Aug 4-5, 2020.
17. Hsingtzu Wu, Alexander Grahn, Soeren Kliem, Verification of a coupling interface for DYN3D and OpenFOAM with a three-dimensional mini-core, Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020, a virtual meeting, May 18-22, 2020.
16. Hsingtzu Wu, The integrated tight coupling method applied to neutronic and thermal-hydraulic coupling, CDNET2019, Beijing, China, Oct 10-11, 2019 (in Chinese).
15. Hsingtzu Wu, Shaoxuan Wang, Evidence-based proposition about an additional defense-in-depth barrier, 2019 ASRTU meeting in Irkutsk First Forum on Green Engineering of ASRTU, Irkutsk, Russia, Sept 15-18, 2019.
14. Hsingtzu Wu, Experience of teaching gas-liquid two-phase flow using PBL pedagogy, proceedings of 2019 National School of Energy and Power Reform of Teaching Methods Conference, Zhenjiang, China, July 13-14, 2019 (in Chinese).
13. Hsingtzu Wu, Compare Spent Fuel Computed with Nuclear Fuel Cycle Simulation System (NFCSS) with Real World Data, proceedings of the 27th International conference on Nuclear Engineering (ICONE27), Tsukuba, Japan, May 19-23, 2019.
12. Hsingtzu Wu, Resent Activities for Analyses of PWR Cladding During LOCA Conditions, the 24th International QUENCH Workshop, Karlsruhe, Germany, Nov 13-15, 2018.
11. Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, Masaki Amaya, Axial Load Behavior Analysis of Zircaloy-4 in LOCA Quench Conditions, proceedings of the 23rd International conference on Nuclear Engineering (ICONE23), Chiba, Japan, May 17-21, 2015.
10. Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, Tomoyuki Sugiyama, Masaki Amaya, Analysis of the Transient Behavior of PWR Cladding During the Cooling Phase Simulated LOCA Experiment, proceedings of 2015 International Congress on Advances in Nuclear Power Plants (ICAPP2015), Nice, France, May 3-6, 2015.
09. Hsingtzu Wu, Yutaka Udagawa, Takafumi Narukawa, Masaki Amaya, Investigation of the Occurrence of a Load Spike in LOCA Quench Experiment, proceedings of 2015 Annual Meeting of Atomic Energy Society of Japan, Hitachi city, Japan, March 20-22, 2015.
08. Hsingtzu Wu, Yutaka Udagawa, Tomoyuki Sugiyama, Takafumi Narukawa, Masaki Amaya, Analysis of PWR Cladding Transient Load under LOCA Quench Conditions, proceedings of the 2014 Water Reactor Fuel Performance Meeting/Top Fuel (WRFPM2014), Sendai, Japan, September 14-17, 2014.
07. Hsingtzu Wu, Rizwan-uddin, Development of a Distance Nuclear Engineering Laboratory, proceedings of the American Nuclear Society (ANS) 2011 student conference, Atlanta, Georgia, April 14-17, 2011.
06. Hsingtzu Wu, Zachary Kriz, Rizwan-uddin, Development of 3D Virtual Reality for Training in Nuclear Engineering, proceedings of the American Nuclear Society (ANS) 2011 student conference, Atlanta, Georgia, April 14-17, 2011.
05. Zachary Kriz, Russell Prochaska, Cody Aaron Morrow, Cesar Vasquez, Hsingtzu Wu, Rizwan-uddin, UT-3 Based 3-D Virtual Models for Training at Nuclear Power Plants, proceedings of the 1st International Nuclear and Renewable Energy Conference (INREC10), Amman, Jordan, March 21-24, 2010.
04. Carl Rytych, Lewis Conley, Hsingtzu Wu, Rizwan-uddin, Game-Like Environments for Nuclear Engineering Education using GECK, proceedings of the 1st International Nuclear and Renewable Energy Conference (INREC10), Amman, Jordan, March 21-24, 2010.
03. Zachary Kriz, Hsingtzu Wu, Cody Aaron Morrow, Carl Rythch, Lewis Conley, Russell Prochaska, Cesar Vasquez, Rizwan-uddin, An Assessment of a Game-Like 3D Model for Training at NPPs, proceedings of American Annual Conference, San Diego, California, June 13-17, 2010.
02. Chen Xi, Hsingtzu Wu, Arwa Joher, Leo Kirsch, Cheng Luo, Mohammed Khasawneh, Rizwan-Uddin, 3D Virtual Reality for Education, Training and improved Human Performance in Nuclear Applications, Proc. ANS NPIC HMIT 2009 Topical Meeting—Nuclear Plant Instrumentation, Controls, and Human Machine Interface Technology, Knoxville, Tennessee, April 5-9, 2009 (CD-ROM).
01. Wu Hsingtzu, Rizwan-uddin, Live Webcast of a Nuclear Engineering Laboratory, proceedings of the conference on Nuclear training and education (CONTE), Jacksonville, Florida, February 8-11, 2009.
updated in May 2025