18 Jan (NucNet): Specialists at China National Nuclear Corporation (CNNC) have successfully 3D printed a lower tube socket for the CAP1400 pressurised water reactor fuel assembly – the first time 3D printing has been used to construct nuclear fuel elements in China, CNNC said in a statement.
State-owned CNNC said the assemblies in a nuclear reactor are cell structures that consist of cylindrical fuel rods and complex metal parts that keep the rods in place.
The various parts require high-precision manufacturing, something that has traditionally made it an expensive task. However, CNNC has now found these parts can be mass produced using 3D-moulding tools based on 3D printing – greatly shortening the product development cycle, improving productivity and significantly reducing costs.
CNNC said the use of 3D-printed parts is in the pre-acceptance phase and the parts will undergo extensive testing. If successful, the company will use 3D-manufacturing techniques to produce other parts that have a complicated shape.
The company said that over the coming years it will increase the use of 3D-printing technology with an eye on manufacturing key components for small reactors such as reactor pressure vessels and main steam pipes.
The 3D printer CNNC has been using was developed and produced by Bright Laser Technologies of Xian city, the capital of Shaanxi province in central China.
CNNC has also signed an agreement with NanFang Additive Manufacturing Technology Company, setting up a collaboration with CNNC subsidiaries China Nuclear Power Institute and China Nuclear Power Engineering Company for the development of 3D printing technologies.
CNNC assistant general manager Li Xiaoming said 3D printing could revolutionise nuclear-power equipment design and manufacturing. According to www.3ders.org, an online publication specialising in the 3D-printing industry, several experts have said it could take “up to 10 years” before the technology is widely used in the nuclear sector for manufacturing parts and components needed in large numbers.
CNNC develops, designs, constructs, and operates military nuclear and civilian nuclear stations. It also develops, produces, and markets nuclear equipment.
The CAP1400 is an enlarged version of the Westinghouse AP1000 pressurised water reactor. China has said development of the plant is one of 16 strategic projects under its National Science and Technology Development Plan. The CAP1400 is intended to be deployed in large numbers across the country and may also be exported.
3D technology was introduced to the nuclear sector by Sellafield Ltd in the UK in 2014. The company, which runs the Sellafield nuclear site in Cumbria, England, said it had become the first nuclear company to experiment with innovative new uses for 3D scanning and printing.
Sellafield said it hopes to combine metal and plastic 3D scanning and printing to help it decommission some potentially hazardous plants.
Sellafield said it had already used 3D blue-LED scanning technology to design a new lid for a 40-tonne solid waste export flask, which is used to ship radioactive sludge across Sellafield site.
A conference has been held at Sellafield to look at various ways of using 3D metal-printing technology, a process which fuses together very fine layers of metal powder with a focused laser beam, to create parts and components made of high-performance metals.
Donna Connor, head of technical capabilities at Sellafield, said the application of this technology had “a high potential of cost and time saving” when manufacturing spare and replacement parts of a one-off design. She said: “Using this technology can revolutionise the way we do things, saving time and money for the taxpayer.”
