Dr. Om Pal Singh
Visiting Professor
Indian Institute of Technology, Kanpur

Abstract

A nuclear reactor is called neutronically decoupled when a local disturbance is not felt in other part of the reactor core. Consequently, the same cannot be monitored by global control system and space dependent flux monitoring becomes necessary. This phenomena is dominant in large size reactors with size more than many migration lengths. In this situation, many generations of neutrons have to pass before the local disturbance can be felt in other parts of the core and the local flux tilt get smoothened. One of the important method to study this phenomena is through Eigen-Value Separation (EVS). It has been established that smaller the EVS, larger is the degree of neutron decoupling, larger is the tilt in the neutron flux and so the need of localized space dependent control system. Modal expansion methodology applied to the problem, shows that higher harmonics of neutron flux makes the core sensitive to the local disturbance and it takes more time for these harmonics to decay naturally and fundamental mode to establish. In the proposed talk, besides introducing the topic of neutronic decoupling, results will be presented on the EVS dependence and the tilting of neutron flux on core size and its shape. The methodology towards optimizing the shape of the core in terms of height to diameter ratio will be discussed. The implication of this on the margin to the Critical Heat Flux and the EVS dependence on the height to diameter ratio in PWRs an PHWRs will be presented. A case study results will also be presented on the growth of localized perturbation in large size reactors like AP-1000, VVER-1000 and EPR-1650 on initiation of xenon instability by ejection of a set of control rods leading to axial local disturbance.

Biography

Dr. Om Pal Singh is Ph.D. in Physics from Indian Institute of Technology (IIT), Delhi, India. He served Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamil Nadu, India for 31 years in different capacities including as Head Reactor Physics Division. His specialization is in Reactor Physics and Deterministic & Probabilistic Safety Analysis of nuclear reactors. He has to his credit over 70 research papers in refereed journals, more than 120 papers presented in conferences and over 200 design and analysis reports on Indian Fast Reactors. He served as Secretary of Atomic Energy Regulatory Board (AERB), Mumbai and Director of one of its division for about 7 years and was involved in regulatory and safety aspects of Indian nuclear and radiation facilities and Human Resource Development (HRD). He carried out R&D on space-time kinetics and safety analysis of Pressurized Water Reactors (PWRs). During the above period, he served as member in the Steering committee of International Atomic Energy Agency (IAEA) on HRD in member states with nuclear power plants. He provided the IAEA Expert Services several times in Indonesia (1988-1991). He has been Chief Investigator from India in 3 IAEA`s Coordinated Research Projects including one on IAEA & European Commission joint project on Russian BN-800 (FR) Safety Analysis. He is also an holder of German Alexander Von Humboldt Foundation research fellowship.

He joined IIT Kanpur as visiting professor in the first week of August 2010 and served the institute for 11 semesters during 2010-2017. He guided 1 Ph.D. thesis and 8 M.Tech theses on topics relating to advanced nuclear reactor technologies. He has keen interest in quality of education of students in schools. He was secretary and vice president of `KG Association` in kalpakkam for 4 years and served for 2 years as Chairman of `Managing Committee` of Department of Atomic Energy (DAE) `s 6 High Schools and 1 intermediate college at Anushaktinagar in Mumbai. For school students, his slogan has been `learning without knowing that one is learning`.

***This seminar will be streamed live on our NCStateNuclear YouTube channel***