ORNL says 3D-printed composite forms cut nuclear concrete mold lead time from six months to two weeks
ORNL says its 3D-printed composite forms cut lead time for specialized nuclear concrete molds from about six months to about two weeks. The forms are in full-scale demonstration on the Oak Ridge campus where Kairos Power is building its Hermes reactor.
The Product Desk
Kairos Power plans such forms for portions of Hermes. Barnard Construction's feedback led to design changes. Shielding panels get grout-free joints hard to make in steel. Faster forms bring no guaranteed cut in reactor build time. ORNL says it is helping set up a supply chain for future reactors.
- Who has to decide decision Kairos Power Plans to use forms like the demonstration ones for portions of the Hermes reactor facility, claim 2
- What's now possible capability Barnard Construction Gave feedback during implementation, leading to design changes for deploying the forms on site, claim 3
- What's now possible capability Radiation-shielding panel designs Interlocking joints for grout-free assembly, a geometry hard to make with steel molds, claim 7
- What it limits constraint Nuclear projects Faster form production carries no guaranteed cut in overall reactor build time, claim 10
- Who's exposed exposure Future advanced reactor projects ORNL says it is helping set up an additive manufacturing supply chain for nuclear construction, claim 12
| Who | How | Kind | Claim |
|---|---|---|---|
| Kairos Power | Plans to use forms like the demonstration ones for portions of the Hermes reactor facility | decision | 2 |
| Barnard Construction | Gave feedback during implementation, leading to design changes for deploying the forms on site | capability | 3 |
| Radiation-shielding panel designs | Interlocking joints for grout-free assembly, a geometry hard to make with steel molds | capability | 7 |
| Nuclear projects | Faster form production carries no guaranteed cut in overall reactor build time | constraint | 10 |
| Future advanced reactor projects | ORNL says it is helping set up an additive manufacturing supply chain for nuclear construction | exposure | 12 |
What happened
- The project, "Advanced Composite Formwork for Accelerated High-Precision Nuclear Infrastructure," won the 2026 CAMX Combined Strength Award.
- The forms are fiber-reinforced composite and include interlocking joints designed for grout-free assembly of radiation-shielding panels, a geometry that is hard to make in steel.
- In the Janus demonstration, three sections of 10 feet by 10 feet were stacked into a cast-in-place concrete shielding column.
- ORNL reports the forms held one-sixteenth of an inch on critical surfaces while withstanding the pressure of the concrete they shape.
- The demonstration forms are precursors to those Kairos Power and Barnard Construction plan to use for portions of the Hermes facility.
Why it matters
- Who has to decide decision Anyone specifying formwork for complex shielding has a new item to put to suppliers: whether a printed composite form can replace the steel order on a joint-heavy design.
- What it limits constraint The two-week figure is ORNL's own, relayed by one outlet, so it supports a request for quotes more than a rebuilt schedule baseline.
- What it sets up precedent ORNL says the project is helping set up an additive manufacturing supply chain for nuclear construction, so other advanced reactor builders could be offered the same forms.
Barnard Construction, the construction partner on the Kairos Power work, gave feedback while the forms were in use, and the ORNL team changed the design to meet construction requirements [3]. A change of that kind is cheap only if the next mold arrives fast. On the figures ORNL gave, a printed form arrives in about one-thirteenth of the time a steel mold takes [13].
A reader skimming a months-to-weeks headline may assume a faster mold means a faster reactor. The report is more careful. The demonstration shows the technology on specific concrete structures, and Interesting Engineering, the outlet reporting the award, says that does not mean the entire Hermes facility is being built with 3D-printed formwork [9]. It says the immediate benefit is faster production of specialized forms and that a shorter reactor build is not guaranteed, because nuclear projects still face regulatory and other construction requirements [10].
ORNL frames the work as a change in how reactors are built. "Accelerating advanced nuclear deployment requires rethinking how we build, not just how we design reactors," said Ahmed Arabi Hassen, group leader of Composites Innovation at ORNL [11]. The report does not give a cost per form or say how many pours a reusable form survives.
The buyer is the owner or contractor who has to order specialized forms for a complex shielding structure. We would use the two-week figure [8] to request quotes and hold the schedule baseline until a delivered form is in hand. The cost of that caution is that any gain stays on paper in the meantime.
Two inputs sort the decision: whether the mold sits on your critical path, and whether the design is still moving. On the critical path with a moving design, the two-week figure matters most. On the critical path with a settled design, a steel wait of about six months [8] can be ordered around, so the saving is smaller. Off the critical path with a moving design, lead time costs no schedule, and the open point is whether a printed form cuts rework. Off the critical path with a settled design, we would stay with steel.
What to watch
- A Hermes pour that uses production forms from Kairos Power and Barnard, as opposed to the Janus precursors.
- A published cost per form and a count of pours each reusable form survives, from ORNL or its partners.
- Orders from other advanced reactor builders through the supply chain ORNL describes.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence40
- Adoption20
- Hype gap+15
- Incentives
- Not scored
- Confidence50
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
In the Janus demonstration, a cast-in-place concrete shielding structure, each section measures 10 feet by 10 feet, with three sections stacked to create a column.
- [2]
The demonstration forms are precursors to those Kairos Power and construction partner Barnard Construction plan to use for portions of the Hermes reactor facility.
- [3]
Barnard Construction provided feedback during implementation, allowing the team to make design changes based on construction requirements and improve how the forms could be deployed on site.
- [4]
The technology has progressed to full-scale demonstrations at Kairos Power's Oak Ridge campus in Tennessee, where the company's Hermes Low-Power Demonstration Reactor is under construction.
- [5]
Oak Ridge National Laboratory and its collaborators developed 3D-printed composite forms that could speed up construction of advanced nuclear facilities, cutting the time needed to produce specialized molds from about six months to about two weeks.
- [6]
The project, titled "Advanced Composite Formwork for Accelerated High-Precision Nuclear Infrastructure," received the 2026 CAMX Combined Strength Award.
- [7]
The ORNL-led team developed fiber-reinforced composite forms for geometries that are difficult to produce with conventional steel molds, including interlocking joints designed to support grout-free assembly of radiation-shielding panels.
- [8]
According to ORNL, the reusable forms can be designed, 3D printed and delivered in about two weeks, compared with approximately six months for conventional steel molds.
- [9]
The demonstration shows the technology's application to specific concrete structures; it does not mean that the entire Hermes facility is being built using 3D-printed formwork.
- [10]
The immediate benefit is faster production of specialized concrete forms, with no guaranteed reduction in the overall time required to build a reactor, because nuclear projects still face engineering, safety, regulatory and other construction requirements.
- [11]
Ahmed Arabi Hassen, group leader of Composites Innovation at ORNL, said: "Accelerating advanced nuclear deployment requires rethinking how we build, not just how we design reactors."
- [12]
ORNL says the project is helping establish an additive manufacturing supply chain for nuclear construction, with the goal of improving manufacturing flexibility and supporting future advanced reactor projects.
- [13]
On ORNL's figures, a printed form takes about one-thirteenth of the time of a steel mold (about 26 weeks versus about 2 weeks).
- [14]
The forms achieved a reported precision of one-sixteenth of an inch on critical surfaces while withstanding the pressure exerted by the concrete they shape.
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Sources
1 independent publisher whose own reporting we read for this story.
- interestingengineering.com3D-printed composite forms could cut nuclear construction time from months to weeks
1 article · October 15, 2026
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