New Alloy Enables Nuclear Reactors to Safely Work 200 Degrees Hotter

A team at Idaho National Laboratory in collaboration with groups at Argonne and Oak Ridge national laboratories, as well as industry consultants and international partners, has for the first time in 30 years gotten a new material, Alloy 617, into the Boiler and Pressure Vessel Code. A combination of nickel, chromium, cobalt and molybdenum, Alloy 617 can be used in tomorrow’s advanced nuclear plants because it allows higher temperature operation.

Oak Ridge National Labs is developing 3D printing of a nuclear reactor core using Alloy 617. The previously allowed high temperature materials could not be used above about 750o C (around 1,380o F). The new Alloy 617 can be used in design and construction up to 950o C [about 1,750o F]. This will enable new higher temperature concepts.

The achievement means that designers working on new high temperature nuclear power plant concepts now have 20% more options when it comes to component construction materials.

There were only five qualified materials for high temperature nuclear reactors before this one was added.

SOURCES- Idaho National Lab, ORNL
Written by Brian Wang,

6 thoughts on “New Alloy Enables Nuclear Reactors to Safely Work 200 Degrees Hotter”

  1. Have something else absorb the neutron in a pool type reactor (e.g. Sodium, Potassium, salt, etc) and greatly reduce the neutron flux at the walls?

    Alternately go for a fast reactor with lead cooling and let the fast neutrons bounce off the Cobalt in the walls due to lower cross section for fast neutrons?

    Yes I’m aware that LWR/PWR vessels are radioactive after use but Cobalt 60’s half life isn’t that long.

  2. Cobalt is such an issue, that all Stellite has been taken out of all domestic LWR. Fleet goes to GREAT extents to minimize cobalt; I’m pretty sure it STILL ranks very high in contribution to dose because there would be tramp cobalt in all ferrous metals. Dose is really low at LWR you know, unless you listen to experts like Bernie Sanders.

    I’m pretty sure user “Michael Chace” has a good point about cobalt, but I concede that you are also likely right, in that this alloy, if it contains cobalt, will not be used in areas that will activate it.

  3. Neutron activation is well understood and I am sure it was taken in to consideration.

  4. Cobalt is a concern. In Navy nuclear reactors, the only component that contains cobalt in an alloy are the seats of the Main Coolant Cut-out Valves – they isolate the primary coolant loop from the reactor core. When they slam shut, it’s felt throughout the submarine. Only a cobalt alloy is strong & tough enough to withstand that kind of abuse.

  5. OK, I’ve done some basic googling now, and it seems to be corrrosion-resistant to water at those temperatures, and is under consideration as a material for ultra-supercritical “boilers”.

    On the flipside, I just re-read Brian’s post, and it mentions that the alloy contains COBALT. My understanding is that tends to produce dangerous amounts of cobalt-60 under neutron irradiation. Maybe this was taken into consideration, and it would be a huge oversight if it wasn’t.

  6. Alright, does it stand up to water corrosion at those temperatures? This is very far into supercritical fluid territory, where the water becomes a weird mix between a liquid and a gas. This is very helpful for power generation, allowing for a more efficient (45% vs 30%) power conversion (from well-proven supercritical steam turbines) in a smaller package(no need for a PWR’s steam generator or a BWR’s miscellaneous steam handling equipment.) Thing is, multiple countries have done research on SCWRs, but the materials just weren’t there at the time.

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