Bradwell Nuclear Power Station FED Retrieval Crane

Bradwell Nuclear Power Station
FED Retrieval Crane
To facilitate the decommissioning of part of Bradwell Nuclear Power Station, SCX Special Projects
provided a semi-automatic FED (Fuel Element Debris) Retrieval Crane.
The crane facilitates waste handling throughout the plant: removing drums containing waste from a
cross-site transporter and transporting them to and from a tipper and sorting table; transferring
baskets containing the sorted waste to and from a dissolution vessel; and stacking trays
containing the remaining waste following dissolution into a Mosaic ready for export.
The crane control system design utilises semi-automatic positional control. The operator is able
to select one of 19 pre-determined automatic pathways via the push of a button, within pre-set
sequence parameters. Manual operation then enables the operator to accurately couple the crane
with each of the various load types.
Semi-automatic control is facilitated from a SCADA
system connected to the crane’s PLC controller
over a dedicated communications network,
supported by safety interlocks and a dedicated
hardwired Engineered Protection System. The
operator is simply required to select the required
crane sequence from the screen menu.
In semi-automatic mode, the crane travels at 4m/min on the
long travel motion and 2m/min on both cross travel and hoisting, but is
restricted to 0.2m/min to ensure fine control when in manual mode.
The modified standard hook block features a pintle adapter, enabling the crane
to couple with and lift the drum grab, baskets and trays.
The use of manual control for coupling the modified hook block and pintle to the
loads, overcomes any positional inaccuracies that may occur when the loads are manipulated by the sorting machinery or cross-site transporter.
The control desk is remotely located in a separate building to
ensure containment and the operations are monitored by CCTV. Additional
CCTV cameras mounted to the underside of the hoist provide the operator with
the ideal view of the pintle and load for accurate positioning.
The MotoSuiveur (MS) hoist safety system mounted directly to the drum provides independent failsafe protection against overload, overspeed and load drop, as
well as incorporating the MS units own independent hoist recovery option.
A rotary encoder and switch mounted on the MS unit provides continual feedback on the position of the hoist.
Bullet systems provide independent
recovery on both the cross-travel and
long travel motions. Using a wire rope
and winch arrangement, the bullet
triggers a paddle to release the crane’s
brakes and then interlocks to recover it
back to a safe area.
SCX Special Projects | 0114 243 1142 | [email protected]

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