CERN ATOMTEX BDKG-24, Руководство пользователя

Страница: 66 / 93

REFERENCE EDMS NO. REV. VALIDITY
TOF-TAR-PRD-0001 1867100 1.0 RELEASED
Page 66 of 93
Name of task
470. Drill hole in
target to drain
moderating circuit
Exposed people 0
Local dose rate 2000 µSv/hr
Workforce 4 people
Time needed 2 hours
Calculated dose
Responsible EN-STI
Involved EN-STI/ EN-SMM/ EN-HE/
HSE-RP
Comments:
The drilling will be performed remotely with a robot
(Teodor).
The water container will be prepared before. The water
container will be the ‘ Bonbonne 50 l ’ (described in EDMS
1723932, SCEM 55.50.40.610.0). The extra capacity is to
make sure that even if the two circuits mixed accidentally,
the water container would be able to contain everything.
The valve to the moderating water container will be open.
The valve to the cooling water container will be closed. This
can be done by hand before the target arrives.
The water container will be connected by a flexible hose to
the draining tray.
The location of the hole needs to be decided. The lowest
point (which would allow the maximum amount of water of
drain) has a groove, which would make drilling difficult. The
area around the groove might be slightly deformed by the
heat that was produced by the welding.
Various holes might need to be done in order to make sure
that all the water is out. A small hole (such as a 4 mm hole
inside the groove) might get blocked, as it is likely that the
water will contain solid fragments.
Smear tests will be done before and after the drilling close to
the holes.
RP needs to collect approximately 0.25 l of the cooling water
from the target.
The material that will be drilled is EN-AW-5083.
Groove (the flat
surface is 4 mm)