Dry Underwater Bushings in High Radiation Fields

[AnthonyJ777]

Hello All,

I'm looking into broadening my departments horizon on available bushing material for some of our equipment designs. Quick background, I work in the nuclear industry and develop hand operated equipment that interfaces directly with irradiated fuel assemblies. The bushing must be able to withstand the dose and heat produced from an irradiate fuel assembly. No greases, oils, etc. are allowed in the plant primary coolant system (spent fuel pool, reactor pool) so all bushings currently have to operate dry or rather with water as lubrication.

When I joined the department, the most common bushing material used was SAE 660 which is a standard bronze material. I've had many bushings seize and lockup using this material or have scarring after only several uses. This is mostly caused from not having an oil film, in my opinion as the bronze is not self lubricating.

After doing some research I've started trying Graphalloy products as its self lubricating underwater. Our first deployment of equipment with this bushing material performed well until after a few days attached to the fuel assembly. It appears possibly they began to swell, which we can account for in future designs.

What I'd like to know is if there's any other options out there we can pursue, or does anyone have any similar experiences they can share?



Regards,

~Anthony

 

[AnthonyJ777]

A small update to this thread in effort to gain more traction.

I inspected the Graphalloy bushings post deployment after they had spent ~72 hours resting on top of an irradiated fuel assembly. Thankfully no swelling, scarring, or wear was found and will be going back in the field next month. Due to the cost and lead times to acquire these bushings I'm still open to other suggestions if anyone else has any experience here.

To recap; I'm looking for underwater bushing materials that are designed for self-lubrication and can withstand radiation dose.


Regards,


~Anthony