DOE 2000. - Waste Isolation Pilot Plant - U.S. Department of Energy

WIPP RH PSAR DOE/WIPP-03-3174 CHAPTER 4
Transfer Cell Shuttle Car
The Design Class IIIA rail-mounted, chain-driven shuttle car (Figure 4.2-17) is designed to transfer either
one 72B cask from below the CUR floor shield valve to below the Transfer Cell ceiling shield valve or
one facility canister in a shielded insert from below the Hot Cell shield valve to below the Transfer Cell
ceiling shield valve. The shuttle car is a steel frame structure about 20 ft (6 m) long. 6 ft (1.8 m) wide,
with a 10 ft (3 m) deep pocket for holding either the 72B cask or the shielded insert.
The transfer cell shuttle car chain drive system, located at the west end of the Transfer Cell, moves the
shuttle car at a speed of 10 to 31 ft (3 to 9.4 m) per minute. The chain drive system, with redundant steel
roller chains (1 in wide links with a 3 in pitch), one steel roller chain can move the car, has double-chain
sprockets driven by a solid shaft which penetrates the Transfer Cell wall so that the gear reducer and
electric motor are located outside the Transfer Cell. The gear reducer and drive motor are connected by a
triple V-belt.
Shielded Insert
The Design Class IIIA shielded insert is specifically designed to be used in the Transfer Cell to transport
one loaded facility canister from below the Hot Cell shield valve to below the Transfer Cell ceiling shield
valve. The shielded insert is designed similar to the 72-B road cask but has a larger inner diameter to
accommodate the wider facility canister. The shielded insert will be installed on the shuttle car when
loaded facility canisters, in the Hot Cell, are ready for underground implacement.
Transfer Cell Ceiling Shield Valve
The ceiling mounted shield valve is located under the port connecting the Transfer Cell to the Facility
Cask Loading Room. The shield valve is a 12 in (30.5 cm) deep steel frame which supports a 42 in
(106.7 cm) square shield plate that is 11 in (27.9 cm) thick. The 8 ft (2.4 m) long frame is bolted to the
Transfer Cell ceiling (Figure 4.2-13). The Design Class II electric motor-driven-screw actuator is
attached to the shield plate with a clevis pin. Valve travel from full-closed to full-open position is 42 in
(106.7 cm) at a speed of 3 in (7.6 cm) per second. The shield valve is normally maintained in the closed
position, except during facility cask loading activities. The valve motor is equipped with torque switches
that will automatically shut off power if the valve tried to close against a hanging waste canister. The
shield valve provides permanent shielding and separates the Transfer Cell and Facility Cask Loading
Room for differential air pressure control. Air pressure in the Facility Cask Loading Room is maintained
higher than that in the Transfer Cell. The Transfer Cell shield valve is interlocked to other RH waste
handling system components as follows:
Ç
Ç
Transfer Cell shield valve cannot be opened unless the CUR floor and Hot Cell shield valves are
closed. This minimizes the potential for ventilation air imbalance that could occur if the three
shield valves were open at the same time.
Transfer Cell ceiling and Hot Cell shield valves are interlocked with the shuttle car drive so that
the shuttle car cannot be moved if both shield valves are not closed. This interlock prevents
damage to the canister from shuttle car movement during canister transfer.
4.2-12 January 28, 2003