H. Seetha

Real time simulation and analysis of nuclear core temperature monitoring system for PFBR

Real time simulation of process models are in heavy demand in the present day industrial scenario especially in Nuclear Power Plant scenario. Nuclear core being the most important and critical component in the Nuclear reactor, the primary concern is towards safe and efficient operation of the reactor by adopting better techniques for monitoring and control of the reactor. Effort is on at global level to develop and build a Training Simulator, covering all the reactor subsystems to impart comprehensive training to Nuclear Power Plant operators. This paper describes about the importance of Core Temperature Monitoring System for Prototype Fast Breeder Reactor (PFBR), real time modeling and simulation of core temperature monitoring system, the basic requirements and methodologies adopted for modeling and simulation. The simulation includes run time calculation for all the fuel subassemblies (SA) outlet temperature and plugging or flow blockage of fuel subassembly for Equilibrium core. Equilibrium core is the state where fuel Subassemblies in the core have burnt for a definite period of time. The code calculates the individual subassembly outlet temperature according to flow and power fraction for that SA, Mean core outlet temperature and rise in mean core outlet temperature. At the time of flow blockage of a subassembly, the deviation in individual subassembly outlet temperature increases over its expected value and if it crosses its threshold, the SCRAM signal is initiated i.e. reactor comes to shutdown state automatically. The paper also discusses about the Integration of Core Temperature Monitoring logic model to the Simulator Environment and the integrated testing with simulator.

Modelling and simulation of inclined fuel transfer machine in prototype fast breeder reactor operator training simulator

Indira Gandhi Centre for Atomic Research, Kalpakkam has successfully designed a 500 MWe prototype fast breeder reactor (PFBR). It is a proven fact that the critical factor in ensuring safe and reliable operation of any nuclear power plant is a qualified and well-trained personnel and hence, the need for operator training using a simulator. Fuel handling is one of the most important subsystems in a prototype fast breeder reactor. Ex-vessel subassembly transfer is done using an inclined fuel transfer machine (IFTM) which operates remotely and safely. Using IFTM, fresh fuel assemblies are loaded into the reactor, and spent fuel assemblies get unloaded. This paper deals with modelling and simulation of operations of IFTM in a simulator. Virtual panel models and control logic models were modelled using modelling tools present in the simulator. The process modelling was developed in-house using platform independent C++ code with 3D models.

Simulation of control logics for plant transition state for PFBR Operator Training Simulator

In any nuclear power plant safety is assured by well defined procedures & practices and by implementing redundant & diverse technology. Procedures concern to the component/system will vary from state to state. Prototype Fast Breeder Reactor (PFBR) is a 500 MWe capacity, pool type reactor utilizing liquid sodium as a coolant and fuel as Mixed Oxide (Plutonium and Uranium). In general there are two reactor states inPFBR i.e. Transition state and Stable state. Wherein steady state indicates stable operating or shutdown state of reactor and transition state indicates an intermediate state between two stable states and this state ensures the healthiness of redundant/diverse system and its auxiliary system. This paper discusses about control logic simulation & implementation of Reactor Start-Up (RSU) system i.e. one of the transition state of PFBR which comes in-between Reactor in Shutdown (RSD) and Reactor in Operation (ROP). It elaborates about interfacing of various process conditions, authorization for reactor startup, inter connection of safety shutdown system, integration and testing of the simulated startup logic.

Formal representation of knowledge using Z in fast breeder test reactors

In this paper, knowledge representation using Z, a formal notation, is adapted in mapping Fast Breeder Test Reactor (FBTR) requirements. The most frequent cause of faults in safety-critical real-time computer systems is traced to fuzziness in representing requirements knowledge. Pitfalls using a natural language as a medium for representing the system requirements knowledge were analysed and explored. To ensure the specified safety, it is necessary to represent the system requirements of safety-critical real-time computer systems using formal mathematical methods. This removes the fuzziness in communicating knowledge on reactor system requirements. This paper contains the formal mathematical model for requirement specifications of FBTR systems using Z notation. Finally, the advantages of using formal representation for representing system requirements knowledge of FBTR using Z notations to minimise the ambiguity in knowledge communication and thus improve the safety are summarised.