CERN ATOMTEX BDKG-24, Manual

Page: 36 / 93

REFERENCE EDMS NO. REV. VALIDITY
TOF-TAR-PRD-0001 1867100 1.0 RELEASED
Page 36 of 93
Caution: indium seal (Alpha decay)!
The seal should be solid and easy to remove from
the chamber. It may be fragile. Before removing
the seal, the hole of the chamber will be covered to
prevent any seal parts to fall in it. The seal will be
taken by hand, while wearing gloves. It will be
placed in a plastic bag, and it will be considered
radioactive waste.
There should be alpha contamination
measurements at this stage.
Name of task
260. Remove long
vacuum chamber
Exposed people
Local dose rate 10 µSv/hr
Workforce
Time needed 2 days
Calculated dose
Responsible EN-EA
Involved EN-EA/ EN-HE/ HSE-RP/TE-
VSC/EN-STI
Comments:
Alignment distances from walls written in past by
Sylvain Girod.
Flange diameter of vacuum tube is 504mm.
Without flange, the tube’s diameter is 337.9mm.
If flange is cut, tube will fit through concrete ring
and its support but will need new fixing points to
hoist.
Vacuum tube length is 8898.58mm.
Lowest 1m will be activated/hot.
This will be stored in ISR8 Storage Area.
The removal procedure will be:
- Lift it with Bonfanti crane into EAR2.
- Clamp it below the first cut position (clamp
to be designed by EN-EA).
- Once the top section is hanging from the
crane, and the bottom section held by the
clamp, make the first cut using a manual
saw (HSE-
RP recommends using a “sci
sabre”) . Beforehand, the gap between the
chamber and the pit needs to be sealed
and plastic sheets laid around to contain
the chips from the cutting.
- Attach the clamp to the Bonfanti crane, lift
the bottom section until the position of the
second cut is visible.
- Attach second clamp below second cut
position, repeat procedure to perform the
second cut.
Two clamps are needed.
Once the lower section is on EAR2, it can be laid
down horizontally to perform a third cut, in order to
isolate the most activated part of the chamber.
2.8m
244 kg