RADIATION SOURCEDesign Review

Dmitry GudkovBE-BI-ML

RADIATION SOURCE

General description of the deviceThe device is used for commissioning of the BLMs in the tunnels. The clip (the unit fixed on the BLM) is connected to the safe lead box (the source storage box) by a flexible hose. The source is attached to the metallic cable pushed by the electric motor through the hose in order to achieve the final position inside the clip which is fixed on the BLM. The operator remotely controls the movement of the source keeping safe distance (5 m) from the source. Once the control of the BLM is done the source is pulled back by the electric motor and stored inside the safety storage lead box.

Quantity of cycles (in-out) between two services - 4000, means 4000 BLMs can be checked.

1. Clip attached to the BLM2. Radiation source trolley3. Lead box4. Operator with remote control unit5. Hose6. Cable

1

2

3

4

5

6

5 m

Problems of the existing devices

Movable parts

1. Main problems are the jamming of the source inside the hose during the operation and wear of the wire due to friction in the regions where the hose is bent. The hose rigidity should be increased while the friction between the hose, the source housing and the wire should be reduced;

2. Design of the source housing should be modified in order to reduce the friction;3. Larger wire should be used (the motor allows the use of larger wire);4. The metallic tube inside the ”garage” should be modified, bigger bending radii to be implemented;

possibly increase the length of the ”garage” to reduce the friction;5. All the connections of the hoses to the “garage” should be revised, the robustness in these regions

should be increased;6. All the movable parts are replaced during the maintenance;7. Desirable length of the hose is 1 m bigger (should be ~3 m)8. The function allowing the pulling of the source manually in case of jamming should be considered.

Clip and safety switches

1. Safety switch on the clip is not protected from outside (it can cause it’s damage) can be protected by metallic sheet with t=0.1..0.2 mm; N. B. The end switch on the clip causes the biggest problem. In case the switch does not work when the source achieves the end position, the electric motor continues to push the cable. This can cause cable damage (uncoiling). Uncoiling of the cable causes it’s jamming in the electric motor.

2. Check if the clip available on market can be implemented; the clip used at the present moment is heavy and requires the force application by the operator about 100 times/shift. Consider ergonomic clamp.

3. Different safety switches to be revised in order to improve the reliability of the system.

Trolley

1. The metallic trolley should be kept but can be modified (holes or slots for hose extraction can be added).

2. Softer wheels are required, possibility of blocking the rotation of each wheel should be implemented;

3. Wood panel to be replaced by plastic or aluminium (?);4. Cover support (when the cover is opened) should be enhanced;5. The battery replacement (every 2..3 years) should be possible without dismantling of the panel

(?);6. Tow bar (side tractor connection) on both sides of the trolley;7. Keep continuous dose instrument inside the trolley.

Problems of the existing devices

Remote control panel

1. Cable connector for remote control panel on both sides of the trolley;2. Cable connector on the remote control panel should be on the other side;3. Increase the length of the cable;4. Increase the rigidity of the cable near the remote control panel (cable is heavy, it bends around

the connector;5. Consider a possibility of reduction of the weight and size of the remote panel, the weight of the

cable.

Other

6. Keep cables and hose inside the trolley or cover it differently for protection during transport and storage;

Cable, Source housing, Tube

In order to avoid the cable damage the nylon coated solution is proposed:

In order to reduce the friction between the source and the hose, the pivot can be used:

source

sleeve

Pivot (ø5)

cable

Cable ø2.3 mm

Bending radii 120 mm

Bending radii on the tube inside the lead box are increased to 120 mm:

250

Cable ø2.3 mm

COMMENT: The source should be protected by 100 mm of lead minimum

a1. The existing tube configuration seems ok, 100 mm of “direct” distance:

Cable, Source housing, Tube

Cable, Source housing, Tube

1

1. The safety switch is moved from the end cable position (old version of the irradiator) to the wall of the lead box.

2. Two fractions of cable are used. Interconnection between the long cable and short cable fraction which holds the source is used to activate the safety switch.

3. No need to calculate exact length of the cable.4. Two safety switches are used at the position “source in the box”5. Mechanical lock

Cable (to reel)

2

Source safety box

3

34

ø5

Cable, Source housing, Tube

Safety switch is moved to the side of the lead box due to lack of the vertical space:

Hose

1

1. Rigid tube is used to guide the cable from the lead box to the wall of the trolley.

2. The hose – tube interface is located outside the trolley on the wall

3. Spring is used to increase the hose rigidity in the interconnection region

2swivel

3

COMMENT: Safety switch should be integrated (motor is blocked when there is no hose connected)

Hose

1

2

1. Rod attached to the hose2. Switch

Clip. Enhanced “classic” clip

1. Hose rigidity is increased (spring is used)2. Internal surface of the hose is protected

by the cover3. Two safety switches are used at the

position “source in clip”4. Clip can rotate around the hose (swivel)5. Switch housing part can be used with

different types of clips

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2

3

4

5

COMMENT: The distance between the end switched and the final position of the source should be approximately 20..30 mm - to be checked

Clip. Enhanced “classic” clip

COMMENT: The distance between the end switched and the final position of the source should be approximately 20..30 mm - to be checked

Clip. Click-type1. 50% lighter than “classic” clip2. Only one movement is necessary to attach the clip to

the BLM3. Felt sheet can be used to reduce the friction during

the connection of the clip and protect the BLM from scratches

4. Easy access from the back side of the quad5. Switch housing is the same for all the clip types

(including “classic”)

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3

4

5

COMMENT: Check this solution with all possible types and locations of BLMs

Cable storage

1. The use of reel allows to store up to 5 m of cable2. Screw shaped cable slot for smooth cable collection3. Reel moves transversally to provide constant cable

orientation (ball screw transmission is used)4. Torque spring is used for cable retraction

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23

4

65

ø90

Modifications of trolley

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2

3

45

1. Tow bar (side tractor connection) on both sides of the trolley2. Gas springs are used for smooth opening of the cover and keep it opened3. Welded eyes (x 4) for fixation during transport by a truck4. Spring forced castors for smooth transport inside the tunnel5. Swivel-block mechanisms on each castor

Gas springsNorelem 26200-0615150X150

Tow bar (same as already installed, drawings are

needed to produce the 2nd)

Modifications of trolley

Weldable Eye Norelem 07720-1000

Spring loaded castor(phenolic group mat.)

Swivel lock mechanism

Mounting dimensions (check if the existing holes can be used)

Modifications of trolley

1. Access to the batteries is provided by sliding the panel out the trolley by 280 mm

2. Continuous dose instrument inside the trolley

3. Batteries can be replaced without full dismantling od the device

2

batteries

1

3

COMMENTS: 1. Battery charger should be integrated (fixed on the

movable platform) 2. Solution to avoid tumbling of the trolley to be

designed

Modifications of trolley

COMMENTS: 1. Battery charger should be integrated (fixed on the

movable platform) – patch panel2. Solution to avoid tumbling of the trolley to be

designed – center of mass

1

2

1. Cable connector for remote control panel on both sides of the trolley;

2. Cable connector on the remote control panel should be on the other side;

3. Increase the length of the cable;4. Increase the rigidity of the cable near

the remote control panel (cable is heavy, it bends around the connector;

5. Consider a possibility of reduction of the weight and size of the remote panel, the weight of the cable (radio/cable)

Other

6. Keep cables and hose inside the trolley or cover it differently for protection during transport and storage;

Remote control panel and cable

1 1

6

250 x 150 x 80

2

2

5

COMMENT: 2nd cable connector is not needed

Manual pulling of the cable

PULL

1. The operator can not approach the trolley if the source is outside the lead box

2. The cable is locked between the rollers of the electric motors3. The only place from where the cable can be pulled is between the

motor and the lead box4. Another cable can be attached in this place so the operator can

pull the cable without approaching the trolley

15 m to operator

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3

4

Prototyping

Test bench phase 1: cable with nylon coating and switch housing parts:

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2

31. Hose2. Tube3. Switch housing

Results: - 10500 cycles completed (corresponding to 10500

BLMs)- No visible wear of cable, hose, tube or switches- No change in cable dimensions- Stability of work during 2 weeks if tests

Prototyping

Test bench phase 2: cable collection device, moving inside the long hose:

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2

1. Cable reel (cable length/travel 3.5 m)2. Hose3. Switch housing

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3

Schedule and future actions

25/03/2015 09/03/2016

01/04/15 01/07/15 01/10/15 01/01/16

25/03/2015Project Kick-off

29/04/2015First Proposals Presentation

15/09/20151st test bench ready

08/10/2015Review Meeting

20/11/20152nd test bench ready

10/12/2015Final design ready

25/03/2015 - 10/12/2015Design

10/12/2015 - 03/03/2016Production of 1st (+1) Irradiator

1. Detailed design of the approved solutions2. 2D drawings3. Production of parts for test bench 24. Production of 1 (+1) x Irradiator5. Tests of Irradiator

Next steps Design Status

3D model Production drawings

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