Removed Q2 15" indium seal ring, discovered seal contained rubber on both sides instead of indium.
- Some kind of oil residue seen at the bottom of the sealing ring and inside of the Q2 vacuum box. (Note: Oil residue was from downstream vacuum roughing pumps. They were connected when T2 M9 joint was leaking. Oil got into the vacuum pump back streamed into the beam line.)
- Probing of rubber seal showed it was still soft at the top and bottom while brittle on the sides near the beam plane (Small pieces broke away when pressure was applied).
- Ring measured 11 µSv on contact, 0.7 µSv @ 1/2 meter, no removable contamination.
Removed a stainless remote handle-able bolt from Q1 cover plate for assaying.
- Bolt removed from South East corner of top cover plate. See photo for location of removed bolt.
- Removed bolt measured 600 µSv on contact, 11 µSv @ 1/2 m, no removable contamination. Bolt placed in a marked lead vial for storage.
- Replaced with identical remote handling bolt in same location.
|