Ansaldo Nuclear has supplied a Fuel Handling Machine Control System (FHMCS) to Russia's Atommashexport to support the latest refuelling operation at the Tianwan nuclear power plant in China.

The FHMCS was provided for Tianwan 3&4, both Russian-designed VVER-1000 reactors. Tianwan 3 entered commercial operation in February 2018 and Tianwan 4 in January 2019.

Ansaldo Nuclear’s scope included the design of the system, manufacture and site support both in Russia for integration tests and in China during commissioning and the first refuelling outages.

The fuel handling system was used over three days in December 2019.

Ansaldo Nuclear was present throughout the refuelling to provide technical support and assistance.

However, operators in China were able to complete the entire refuelling process on schedule with minimal assistance from Ansaldo representatives.

Design of the FHMCS for Tianwan took 18 months to complete. The system, based on microprocessor technology, fully automates the fuel handing process.

The FHMCS features a fully-redundant hardware architecture and power supply. It has various operating modes, including fully automatic, semi-automatic, manual protected and training.

The design is compliant with international requirements and standards, specifically with electromagnetic disturbance immunity demands and seismic requirements, Ansaldo said.

The FHMCS also includes a simulator, which can be used to provide feedback on the real machine movements and emulate the signals coming from the reactor building to simulate malfunctions and emergency situations.

“There are two issues that are critical to avoid during the refuelling process," said Andrea Bagnasco, senior EC&I engineer at Ansaldo Nuclear, who was present during the recent operation at Tianwan.

"The first is any disturbance to the integrity of the fuel element.

"The second is the economic disruption caused to the plant as a result of unexpected delays."

“By designing, manufacturing and installing a control system which effectively streamlined the transport process, whilst protecting against any related safety issues, Ansaldo Nuclear was ultimately able to mitigate both of these threats," he added.

Ansaldo Nuclear has been working with Atommashexport since 2001, providing control systems and site assistance for Tianwan's four fuel handling machines.

Photo: Refuelling operations with the FHMCS took place at Tianwan in December (Credit: Ansaldo Nuclear)