In Nuclear Power Plants, safety systems are key to maintaining the plant in a stable state during severe accidents that occur due to different natural/man-made hazards.
Vaishnvi Tiwari, our next pathbreaker, Nuclear Safety Engineer at Oakridge SAS (France), works as part of a team that performs Safety Analysis for international nuclear projects.
Vaishnvi talks to Shyam Krishnamurthy from The Interview Portal about the immense potential of Nuclear Energy in meeting the future energy demands of our society in a clean and sustainable way.
For students, always find ways to apply your knowledge! Do not restrict yourself to your field. As the world is becoming more and more complicated, there is greater demand for people willing to make the connections between different disciplines to find solutions to complex problems !
Vaishnvi, can you share our background with our young readers?
Born in Allahabad, I grew up in Lucknow, Uttar Pradesh. Together with my elder sister and parents, we lived in a small house. My days began with my father leaving early morning for work (an ENT surgeon working for the State Government Primary Health Care sector in rural areas) and my mother getting us prepped for school. My mother was still pursuing her PhD when I started school. She used to make multiple trips between our home, school and the medical College to make sure we came back home safely, had our meals on time and were on track with our school and home work. Since my parents used to come home late in the evening, my sister and I usually spent our free time by reading books, listening to music and dancing. The radio was our best friend! Honestly, we used to get scolded sometimes for listening too much to the radio.
A typical evening for us was my father teaching my sister from her science books with me playing around, casually listening to him tell us about atoms, the periodic table, even giving lessons in biology (I found genetics quite fascinating back then!) and my mum giving us examples from daily life on different concepts of biology (she is currently working as the Head of Department in Biochemistry). Its safe to say that growing up listening to such examples and hearing my parents discuss their day’s events encouraged me to pursue a career in the field of science, but I think my choice to be a Nuclear Engineer surprised everyone in my family!
What did you do for graduation/post graduation?
After completing 12th grade, I pursued a BSc in Physical Sciences from St. Stephens College, New Delhi and graduated in 2013. Following my graduation, I pursued MTech in Nuclear Science and Technology from University of Delhi, a three year program designed for students with Sciences background, focused on the domain of Nuclear Energy.
I did my PhD at CEA Cadarache (France), which is the largest technological research and development centre for energy in Europe.
What were some of the drivers that influenced you to pursue such an offbeat, unconventional and unusual career in Nuclear Engineering?
My intention of choosing a career in the domain of nuclear engineering was the result of many micro-events in my life. My career, leading up to my present position as a Nuclear Safety Engineer involves a well balanced mix of the basic sciences (and not just Physics!) and engineering studies. And I believe this path was paved because of my choice of subjects for high school and intermediate (I was one of the 3 students in my school to opt for all sciences – Physics, Chemistry, Mathematics and Biology as my majors), and my bachelors degree.
If I were to sum up, I would give credit to my parents for introducing me to the wonders of science (beyond the textbooks), my science teachers at school and most importantly, the time I spent in the labs gaining practical knowledge. I am happy that I was able to incorporate all the aspects of science into my work, which allowed me keep myself updated with all the fields.
How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path
A: Training at Indira Gandhi Center for Atomic Research (IGCAR), Kalpakkam, India: My Master’s degree was the starting point for my career in Nuclear. During the first year, we had the opportunity to visit the Indira Gandhi Center for Atomic Research, Kalpakkam. The 40 days of training was an eye opening experience for me. I not only got to visit the Reactor site and all the experimental facilities, but also had the chance to work on projects with some of the most experienced scientists! My project was to calculate Linear Heat transfer in the fuel pins for a Metal Fuel Fast Breeder Reactor. This may sound all technical, but the aim of this project was to determine the rate at which the heat generated from the fuel will be transferred to the coolant that is flowing outside the fuel assemblies. By determining this rate and the factors that can help to improve the efficiency of heat transfer, one can help to define the limits for safe functioning of the nuclear reactor, without damaging its internal parts. I worked on two different fuel pin designs and compared the heat transfer efficiencies for both designs. This was my first experience in the field of Nuclear Safety!
B: French Atomic Energy Commission (CEA), Cadarache, France: My second experience was through my end of master’s internship at the French Atomic Energy Commission (CEA). For the first time, I was involved in an international project that aimed to improve the accuracy of predicting the fate of a nuclear reactor, in case of a fuel meltdown accident. I worked to develop mathematical models that can define phenomenon like solidification or stratification of molten fuel into density-dependent layers. These mathematical models were then plugged into Reactor Analysis Code to see the effect of the above said phenomena on heat transfer rate and the possibility of containment rupture. To understand this, think of a bowl with hot soup, only that there are multiple layers in that soup, each transferring heat to the bowl at different rate. If a particular layer transfers enough heat that the bowl develops a crack, the soup can come out of the bowl. Only, in the reactor case it will result in release of radioactivity into the environment.
C: Doctoral Research at CEA Cadarache, France: My internship was the starting point to my Doctoral research, where I further delved into the role of thermodynamics in improving the accuracy of the predictions that were made by the models and the Reactor Analysis Code. I worked to develop a methodology on how we can use thermodynamics to provide real-time information on the properties of the materials. This information was then plugged into the models (and the code) to see the effect of changing properties on how sooner/later the bowl of radioactive soup will rupture.
D: PostDoctoral Research at CEA, Saclay and Cadarache: My PhD research exposed me to the realm of material sciences along with nuclear reactor safety. This helped me to land a job as a post doctoral research fellow at CEA. This new job was another wonderful experience for me as I got the opportunity to apply my knowledge to a new generation of Nuclear Reactors! This reactor design (Molten Salt Reactor) is unlike the Nuclear Reactors that are currently under operation. During my project, I collaborated with different nuclear research organizations in Europe. I used the Computational Thermodynamics approach to develop a database on material properties for the molten salt reactor, and to study the interactions between the fuel and the reactor support structure elements.
What is Computational thermodynamics, you ask? Well it is practically impossible to handle radioactive substances all the time to perform experiments to determine their thermodynamic, thermophysical properties. So we use mathematical models again, in addition to the limited experimental data that is available, to predict the chemical, thermodynamic nature of systems. Basically to answer questions like what would be heat capacity, enthalpy, etc. of the material. This may sound boring, but trust me, the world of Analysis codes depend on such data for accuracy.
How did you get your first break?
My internship at the French Atomic Energy Commission was my first break. The internship exposed me to the vastness and the ever evolving nature of Nuclear Reactor Safety domain. The internship connected me with the International nuclear Safety community and compelled me to explore the minute, unanswered questions aimed at improving the safety analysis of Nuclear Reactors.
When I had started my internship at CEA, I was not aware of the possibility of continuing under the same subject for a PhD. When I discovered this possibility, naturally I wanted to pursue it. However, doing the internship did not guarantee my place for the PhD Like all other candidates, I was interviewed by the committee. But I was fortunate that things worked out in my favor and I was selected for a fully funded PhD with a commitment of completion in 3 years.
It is true, getting a job in the French Nuclear Industry is difficult. After my PhD, I faced many rejections for industrial job profiles as well as for postdoctoral projects. OAKRIDGE was a very pleasant surprise for me. Towards the end of my postdoctoral fellowship, I was approached directly by the company for the job position. After having a thorough discussion about the nature of the position, it was clear to me that the present role was the correct step for my career. It allowed me to apply my competencies and at the same time gave me the opportunity to explore Nuclear Safety from a new perspective.
What were some of the challenges you faced? How did you address them?
During my internship and doctoral research, I realized one thing: Passion alone is not enough. My fascination and desire to work in the field of Nuclear Energy was not enough for me to succeed in my job. I faced many challenges during my thesis, some of which are:
Challenge 1: Lack of experience in coding. My last coding experience was during my 10th standard, where I had learned the basics of Java. None of my formations after school involved any experience in coding or use of Computer languages. I was naive to think that just a knowledge of the scientific concept was enough. With the help of my PhD supervisor and my Master’s classmates, I was able to overcome this hurdle. Not only did I learn the essentials of coding, but I also learned the art of converting a scientific problem into a code and using the computer languages to solve these problems.
Challenge 2: Living in a foreign land. My trip to France in 2016 was my first international trip. Safe to say that I was scared of having to live on my own and to make decisions, not only professional, but also the ones that affect my personal life on a daily basis. I did not know the language, which posed another problem. Do not get me wrong, France is very friendly towards people who don’t speak their language. I never faced a problem while I was at work. All my french colleagues spoke in English with me, they encouraged me to learn their language. But spending time at work was limited. When it came to the world outside of office, I did encounter people who did not speak English, places where knowing the French language was essential (take for example while traveling locally, the food markets, the bank, etc.). Learning how to manage day to day situations, mastering the language and understanding the culture took some time and effort, but with the support of my colleagues I was able to integrate comfortably into this new environment. Furthermore, living on my own, managing my finances and making decisions for myself made me confident that I can take care of any personal or professional situation with a little bit of effort and patience.
Where do you work now? Can you tell us what problems you solve?
Currently I am working as a Nuclear Safety Engineer for a French company named Oakridge SAS. In this role, I work with a team to perform Safety Analysis for international nuclear projects. By safety analysis, I mean that for a Nuclear Reactor site that is currently under operation, I take into account a varied list of Internal and External Aggression scenarios that could have an adverse impact, and I model the probability that the plant would release radiation under each of these scenarios.
What are the skills required for your role?
In addition to the knowledge of Nuclear standards, specific analysis tools, nuclear safety concepts and code development, this role requires an interdisciplinary knowledge, and the ability to apply them. For example, when I work on a particular site, I should be able to first make a list of all the internal and external hazardous events that would be specific to that site. Furthermore, I need to be able to identify what scenarios are possible! This is one of the many minute details that a Nuclear Safety Engineer has to pay attention to. And it is not necessary to come prepared with all the skills, some things you learn on the job. You just need to have the right attitude to learn and apply the knowledge to the problem at hand.
Whats a typical day like?
In addition to the usual client and team meetings, my typical day includes reading up of Nuclear Safety Reports, some model development or use of specific tools for probabilistic calculations and production of the safety reports. Each day is different for me, there could be a week where I am reviewing old reports, gathering information from client assessment reports and the next day I could be working on developing the model or performing calculations. There has never been a static routine. And this is one of the things that I love about this job! Yes, we are bound to our client requirements, but the process of performing a safety assessment entails so many tasks! It is a wide range, from bibliographical research to learning a new tool/method for analysis to report writing.
How does your work benefit the society?
My work as a Nuclear Safety Engineer ensures that the nuclear power plants that are currently under operation are well prepared to deal with accidents due to different natural/man-made hazards. This preparedness ensures that in case of an accident, the nuclear installation is still able to perform all safety functions to contain/limit radiation leak into the environment and safely manage radioactive fuel and waste.
Tell us an example of a specific memorable work you did that is very close to you!
Nuclear Energy is not just a professional choice for me. I truly believe in the potential of Nuclear to meet our future energy needs in a sustainable way. During my Masters and PhD thesis, I connected with similar minds who wanted to spread this awareness to as many people as they could. I joined several non-profit organizations that focused on the issue of Nuclear Energy. I volunteered as a content developer for a Senior’s Project (Nuclear Energy The Better Energy Initiative by Nirupama SenSharma) where I wrote articles related to different concepts of Nuclear Reactors and the varied peaceful uses of Nuclear Energy. I worked in the capacity of Editor in Chief for the Indian Youth Nuclear Society (IYNS), where I was in charge of developing the monthly Newsletter “Nuclear News” along with aiding in organizing outreach events. In addition to this, I briefly served on the Editing committee of the International Youth Nuclear Congress (IYNC). All these volunteer experiences are very close to me and they have helped me form some of the most important and unbreakable bonds with the nuclear community!
Your advice to students based on your experience?
Always find ways to apply your knowledge! Do not restrict yourself to your field. As the world is becoming more and more complicated, there is greater demand for people willing to make the connections between the different disciplines to find new solutions to our ever so complex problems in life! Also, it is never too late to learn something new!
Future Plans?
Currently I am working with a Nuclear Science and Engineering Organization in France, where I am contributing to the international Nuclear Projects in the capacity of a Safety Analyst. At the same time, I am exploring the challenges that have been identified for the new generation (Gen IV) Nuclear Power Plants.
One thing that I have learned is to never have a “fixed” future plan, but also never lose focus from your ultimate goal.
So I would like to modify your question 🙂 My ultimate goal is to facilitate international collaborations and be able to make a significant contribution to the Indian Nuclear Power Program – it would be an honor!