Buna-n safety reliefs...

So the Buna-n seals were really weren't Buna-n. It was just Buna. It had some sulfur impurities in the rubber like material...making it all the more susceptible to elevated temperatures.

I asked them a hypothetical, what would happen if the seals turned into dust. I said I thought the manual operation of the valve would be lost, but the auto function would be good. The NRC inspectors thought it would use a lot more nitrogen...but the valves could be manually operated. The inspectors had the valve and actuator drawing/diagram sitting right in front of them...where i was winging it from 20 year old memory. I told them too bad the manufacture didn't have the testing to show us how the valves would respond with totally failed seals...

target rock has issues a service notice or bulletin advising all the nuclear plants to change out their SRV seals with this vitol material.

The seals were originally asbestos seals and we know how high the temperatures asbestos can withstand...it was designed for high temperatures. So asbestos became harmful to humans...that is why the change out into nylon and buna. remember drop the n. The n makes the rubber like material to be more temperature resistance. Why they didn't go to a similar material like asbestos is beyond me.

It was shocking how anticipatory the inspectors were with their honesty...they were giving answers before I could even think up the question.

These NRC inspectors threw me right off my kilter.

I really appreciate the effort the NRC took over this issue on the VY side of things.

Thank You!

There is a big difference between a vendor's voluntary service bulletin notice and a order by the NRc to do something or request for information...

What the name of the new material...Vitol or something...