A 3D-printing process tailored for nuclear energy applications, developed at Oak Ridge National Laboratory (ORNL), is helping industry partner Ultra Safe Nuclear Corp. (USNC) deliver safe, clean and cost-effective electricity and heat with its next-generation reactor. 

Parts made using ORNL’s method, which produces complicated shapes from materials that can withstand high temperatures, will enable USNC to optimize and commercially produce Fully Ceramic Microencapsulated (FCM®) fuel for its Micro Modular Reactor (MMR®).  

Nuclear energy systems convert heat to electricity through nuclear fission, a process in which large atoms split into smaller atoms, releasing energy. Maximum efficiency requires reactor components made from materials like ceramics that can withstand extremely high temperatures.  

While it’s possible to make simple shapes out of ceramic material, nuclear reactors require more complex parts that are not easily produced using conventional methods. ORNL’s technology solved this problem by using a new additive manufacturing (3D printing) process to manufacture complex shapes out of silicon carbide (SiC), a type of ceramic material.  

ORNL’s method combines binder jet technology with chemical vapor infiltration (CVI). Binder jetting involves printing one layer at a time of powdered material, then drawing the powdered particles together using a binding agent before printing the next layer. CVI involves exposing the 3D-printed shape to a gas at extremely high heat, which increases the density of the ceramic material. 

ORNL developed a unique additive manufacturing (3D printing) process to manufacture complex shapes out of silicon carbide (SiC), a type of ceramic material, which can withstand extremely high temperatures.

The finished product is ideal for nuclear energy applications because it can be printed in complex shapes, withstands extreme environments and does not degrade over time.  

USNC’s FCM fuel encases the nuclear fission process within SiC-based cylindrical pellets. Stacks of fuel pellets are placed into graphite blocks, which in turn make up the energy-generating core of the company’s Micro Modular Reactor. The multiple layers protect against environmental contamination, and use of SiC for the fuel pellets provides additional safety as well as improved thermal efficiency.  

ORNL and USNC signed an exclusive license for the technology, and USNC created its new Core division specifically to further develop and commercialize it. USNC had previously licensed technology from ORNL; this history built the strong loyalty and trust that helped make this transfer possible. 

The technology transfer effort was supported by ORNL’s entrepreneurial leave (EL) program, which allows staff to spend time with the licensee to help with commercialization. Three of the inventors left ORNL under the EL program to join the USNC Core division. Transferring the inventors along with the technology contributed to the collaboration’s success. 

At the time of award submission, USNC had already hired 20 new full-time staff and had invested more than $10 million in new manufacturing facilities in Salt Lake City and eastern Tennessee — bolstering those regional economies and helping to expand domestic nuclear energy production.