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Automatic loading equipment for a reactor thermal column
N U C L E A R I N S T R U M E N T S AND M E T H O D S 33 (1965) 306-308; ,~3 N O R T H - H O L L A N D
PUBLISHING
CO.
AUTOMATIC LOADING EQUIPMENT FOR A REACTOR THERMAL COLUMN I. BALLA and G. BEN-DAVID
Israel Atomic Energy Commission, Soreq Research Establishment, Yavne, Israel Received 1 September 1964 Automatic loading equipment is described for the thermal column of the Israel Research Reactor IRR-1. The equipment
The thermal column of the I R R - I * reactor provides thermal neutron fluxes of between 108 and 5 x 10 ~° neutrons/cm 2.sec along the central axis and is being utilized for studying nuclear reactions produced by thermal neutrons. The experiments performed include simple irradiations, as well as experiments requiring the introduction of electronic equipment into the thermal column. Until now the reactor had to be shut down for the loading and unloading of the apparatus and at times considerable cooling periods were required to permit removal of the radioactive components, which interfered with the steady power operation of the reactor. To overcome this difficulty, automatic loading equipment has been installed at the thermal column, which permits introduction and removal of experiments during full power reactor operation. The equipment can handle apparatus weighing up to 250kg and having overall dimensions of up to 23 cm x 26 c m x 65 cm. Among the principal functional features of the equipment is a shielded loading chamber which serves as an entrance lock between the thermal column and the * A 5 MW pool type reactor operated by the Israel Atomic Energy Commission. THERMAL
COLUMN
GRAPHITE?L....../ i x. . . . .
/
x IRRADIATION TUNNEL THERMAL COLUMN
IN T H E
Fig. 1. Diagram of reactor thermal column and loading chamber.
permits experiments to be loaded and removed from the thermal column while the reactor is in operation.
ROOF SHIELDING
, EXPERIMENT CARRIAGE PLATFORM
I
SHIELDING WALLS OF THE LOADING CHAMBER
Fig. 2. Schematic view of the loading equipment.
reactor hall. To prevent escape of radiation into the reactor hall the experiment enters the thermal column through this loading chamber via two interlocked movable shields. A general view of the equipment is shown in figs. 1 and 2. Graphite blocks were removed along the axis of the thermal column leaving an empty space 30 c m x 3 0 c m in cross section and 2 5 0 c m in length. An aluminium framework installed inside this space provides guide rails for the aluminium experiment carriage, which can thus be moved to any desired position within the thermal column. The thermal column entrance is normally closed by a heavy shielding trolley, which moves inside the loading chamber perpendicular to the axis of the thermal column. The heavy shielding block includes boral, paraffin and lead shielding. At the side of the shielding block is fixed a short length of rail which lines up with the internal guide rails when the trolley is in the open position and permits transfer of the experiment carriage from the trolley to the thermal column and back. When 306
AUTOMATIC L O A D I N G EQUIPMENT FOR A REACTOR THERMAL COLUMN
307
d J
z •J
f \
>
J
f •/ j
~.
//"
i
Fig. 3. Experiment loading procedure. (a) Insertion of experimental equipment through roof access opening. (b) Experiment in position on carriage. Replacing roof shielding plug. (c) Shielding trolley being moved to open position. (d) Experiment opposite opening in thermal column. (e) Experiment moving into thermal column. Shielding trolley being moved to closed position. (f) Loading complete. Experiment can be moved to any desired position.
308
1. B A L L A A N D G. B E N - D A V I D
the trolley is in the closed position, the carriage on the attached rail is directly beneath a roof shielding plug, through which experiments can be introduced from the reactor hall onto the carriage. Both the trolley and carriage are driven by electric motors, the former being moved by a threaded shaft and the latter by a chain drive. Their actual positions and the position of the roof shielding plug are indicated by electro-mechanical indicators on the control panel of the system. Electrical interlocks prevent the trolley from being moved from the closed position while the roof shielding plug is open, thus ensuring that no radiation leaks into the reactor hall. In addition the trolley cannot be moved while the experiment carriage is passing between the thermal column and the loading chamber and similarly the carriage cannot be moved in the entrance of the thermal column if the trolley is not in the open position. The roof shielding plug is operated by a small hydraulic crane. Another hydraulic crane is used for loading the experimental equipment through the roof access hole onto the carriage. The normal loading procedure is illustrated in figs. 3a to 3f. With the trolley and carriage in the closed position, the roof shielding plug is removed and the experiment box placed on the carriage. The shielding plug is then replaced and the trolley moved to the open position, permitting insertion of the carriage into the
thermal column, after which the trolley is moved back to the closed position. If necessary electrical cables and gas or liquid tubing for the experiment can be introduced through the shielding system inside a flexible pipe of one inch internal diameter. While an experiment is being performed in the thermal column it is possible to carry out irradiations requiring low neutron fluxes (up to l0 8 neutrons/cm z" see) inside the loading chamber, the apparatus being mounted directly on the shielding trolley without using the carriage. With the trolley in the open position, the maximum radiation level outside the loading chamber at full reactor power is half the tolerance level for gamma radiation and thermal neutrons. With the trolley in the closed position, the external radiation is negligible as a health hazard. This equipment has been working for several months and has already proved its usefulness in routine operation of the reactor. The authors wish to thank the scientific and technical directors of the reactor, Prof. I. Pelah and Mr. A. Arbel, for their cooperation. They also acknowledge the valuable assistance of Messrs. M. Sinai, G. Revesz and A. Siev and the staff of the technical service department.
PUBLISHING
CO.
AUTOMATIC LOADING EQUIPMENT FOR A REACTOR THERMAL COLUMN I. BALLA and G. BEN-DAVID
Israel Atomic Energy Commission, Soreq Research Establishment, Yavne, Israel Received 1 September 1964 Automatic loading equipment is described for the thermal column of the Israel Research Reactor IRR-1. The equipment
The thermal column of the I R R - I * reactor provides thermal neutron fluxes of between 108 and 5 x 10 ~° neutrons/cm 2.sec along the central axis and is being utilized for studying nuclear reactions produced by thermal neutrons. The experiments performed include simple irradiations, as well as experiments requiring the introduction of electronic equipment into the thermal column. Until now the reactor had to be shut down for the loading and unloading of the apparatus and at times considerable cooling periods were required to permit removal of the radioactive components, which interfered with the steady power operation of the reactor. To overcome this difficulty, automatic loading equipment has been installed at the thermal column, which permits introduction and removal of experiments during full power reactor operation. The equipment can handle apparatus weighing up to 250kg and having overall dimensions of up to 23 cm x 26 c m x 65 cm. Among the principal functional features of the equipment is a shielded loading chamber which serves as an entrance lock between the thermal column and the * A 5 MW pool type reactor operated by the Israel Atomic Energy Commission. THERMAL
COLUMN
GRAPHITE?L....../ i x. . . . .
/
x IRRADIATION TUNNEL THERMAL COLUMN
IN T H E
Fig. 1. Diagram of reactor thermal column and loading chamber.
permits experiments to be loaded and removed from the thermal column while the reactor is in operation.
ROOF SHIELDING
, EXPERIMENT CARRIAGE PLATFORM
I
SHIELDING WALLS OF THE LOADING CHAMBER
Fig. 2. Schematic view of the loading equipment.
reactor hall. To prevent escape of radiation into the reactor hall the experiment enters the thermal column through this loading chamber via two interlocked movable shields. A general view of the equipment is shown in figs. 1 and 2. Graphite blocks were removed along the axis of the thermal column leaving an empty space 30 c m x 3 0 c m in cross section and 2 5 0 c m in length. An aluminium framework installed inside this space provides guide rails for the aluminium experiment carriage, which can thus be moved to any desired position within the thermal column. The thermal column entrance is normally closed by a heavy shielding trolley, which moves inside the loading chamber perpendicular to the axis of the thermal column. The heavy shielding block includes boral, paraffin and lead shielding. At the side of the shielding block is fixed a short length of rail which lines up with the internal guide rails when the trolley is in the open position and permits transfer of the experiment carriage from the trolley to the thermal column and back. When 306
AUTOMATIC L O A D I N G EQUIPMENT FOR A REACTOR THERMAL COLUMN
307
d J
z •J
f \
>
J
f •/ j
~.
//"
i
Fig. 3. Experiment loading procedure. (a) Insertion of experimental equipment through roof access opening. (b) Experiment in position on carriage. Replacing roof shielding plug. (c) Shielding trolley being moved to open position. (d) Experiment opposite opening in thermal column. (e) Experiment moving into thermal column. Shielding trolley being moved to closed position. (f) Loading complete. Experiment can be moved to any desired position.
308
1. B A L L A A N D G. B E N - D A V I D
the trolley is in the closed position, the carriage on the attached rail is directly beneath a roof shielding plug, through which experiments can be introduced from the reactor hall onto the carriage. Both the trolley and carriage are driven by electric motors, the former being moved by a threaded shaft and the latter by a chain drive. Their actual positions and the position of the roof shielding plug are indicated by electro-mechanical indicators on the control panel of the system. Electrical interlocks prevent the trolley from being moved from the closed position while the roof shielding plug is open, thus ensuring that no radiation leaks into the reactor hall. In addition the trolley cannot be moved while the experiment carriage is passing between the thermal column and the loading chamber and similarly the carriage cannot be moved in the entrance of the thermal column if the trolley is not in the open position. The roof shielding plug is operated by a small hydraulic crane. Another hydraulic crane is used for loading the experimental equipment through the roof access hole onto the carriage. The normal loading procedure is illustrated in figs. 3a to 3f. With the trolley and carriage in the closed position, the roof shielding plug is removed and the experiment box placed on the carriage. The shielding plug is then replaced and the trolley moved to the open position, permitting insertion of the carriage into the
thermal column, after which the trolley is moved back to the closed position. If necessary electrical cables and gas or liquid tubing for the experiment can be introduced through the shielding system inside a flexible pipe of one inch internal diameter. While an experiment is being performed in the thermal column it is possible to carry out irradiations requiring low neutron fluxes (up to l0 8 neutrons/cm z" see) inside the loading chamber, the apparatus being mounted directly on the shielding trolley without using the carriage. With the trolley in the open position, the maximum radiation level outside the loading chamber at full reactor power is half the tolerance level for gamma radiation and thermal neutrons. With the trolley in the closed position, the external radiation is negligible as a health hazard. This equipment has been working for several months and has already proved its usefulness in routine operation of the reactor. The authors wish to thank the scientific and technical directors of the reactor, Prof. I. Pelah and Mr. A. Arbel, for their cooperation. They also acknowledge the valuable assistance of Messrs. M. Sinai, G. Revesz and A. Siev and the staff of the technical service department.