NEW DELHI: Russia state atomic energy corporation Rosatom’s division Rosatom Automated Control Systems has completed the supply of equipment for engineered safety features actuation system computerised subsystems (ESFAS CS) for units 3 and 4 of the Kudankulam nuclear power plant in Tamil Nadu. The role of the general designer and supplier of equipment in the project belongs to Atomstroyexport.In total, about 300 items of equipment were manufactured and delivered to the plant – four sets of ESFAS CS in accordance with the number of safety instrumentation and control trains, per each power unit featuring VVER-1000 reactors.ESFAS is the system that monitors the process parameters of a power unit when there is a deviation from normal operation conditions. In case of an accident, the system automatically initiates the start of safety instrumentation and control systems and sends commands to actuators (boron injection pumps and other active protection means) in order to prevent a beyond-design-basis accident and bring the reactor plant to a safe state. The system also ensures reactor cooldown, which is a controlled decrease of coolant temperature and pressure down to safe values after the shutdown.To avoid simultaneous failure, they are physically separated — located in different rooms — and have autonomous power supply from separate diesel generators.Specialists developing the ESFAS CS for units 3 and 4 relied on the operating experience of the same system at Kudankulam NPP units 1 and 2, which allowed them to implement a number of optimised solutions. One of such solutions is the application of non-programmable modules that process signals from sensors without the use of microprocessors. This helps to reduce the dependence of safety functions on application software and increases the resistance of equipment to potential common cause failures.The final delivery of ESFAS CS equipment was yet another step of equipping the power units with Russian automation, control and safety systems, implemented through industrial cooperation. Installation on the site will be followed by the pre-commissioning stage, which includes the off-line and integrated tests of the systems.
Following the tests, the systems will be prepared for commissioning and further operation at units 3 and 4 of the Kudankulam plant.Kudankulam plant features six power units with VVER-1000 reactors, with the total installed capacity of 6,000 MW. The first phase (units 1 and 2) was commissioned in 2013 and 2017, respectively. The second phase (Units 3 and 4) is under construction.