The M20 beam blocker was moved from the T2 monolith to the meson hall hot cell with the remote handling flask (completed ~4pm).
This operation was performed in preparation for M20 maintenance (main shaft o-ring replacement + air cylinder re-lubrication).
RPG surveyors measured 20,000 CPM from swiping the surface of the beam blocker shaft, and measured 25 mSv/hr on contact with the beam blocker.
Fields on the hot cell roof were at 100 uSv/hr at 0.5 meters from the top of the M20 BB. This should reduce drastically with the introduction of lead blanket shielding (see attached pictures).
|