Mobile Radiation Shield

Transcription

1 Mobile Radiation Shield December 7, 2001

2 Design Staff John Fader Rob Horrobin Shaun Kurry Jeff White Mobile Radiation Shield Andy Hegedus Scott Kauffman Advisor: Dr. Wilkins

3 Overview Project Definition Problem Definition Design Process Testing and Analysis Handoff Plan

4 Project Definition Exelon Nuclear contracted Team 6 to design and construct a mobile apparatus for shielding workers from low-level radiation emission.

5 Current Method

6 Problem Definition Low-level exposure to workers Cost of installation / removal Labor: $500 Exposure: $5000 Current method is immobile Downtime during installation / removal

7 Team Goal Create vehicle that will: Reduce exposure Save money Reduce set-up time Serve as a prototype

8 Wants and Metrics Customer Exelon Nuclear Constraints The shield device must cost less than $10,000. The controls must be remotely attached by a cable. The shield must use the lead blankets currently in use by Exelon. The shield must be adaptable to protect from a radiation source near the ground as the situation The device must be able to function in a lack of an external light source. The device must be able to pass through a puddle of water with no damage occuring to the device. The device must be controllable without being in direct eyesight. The lead blankets must cover an area that is at least 4 feet by 4 feet (perpendicular to the ground) and the top must be at least 6 feet from the ground and two layers thick. The device cannot tip over. Customer Wants Metrics Target Values Size of shield Area of shield 16 sq. ft. Inexpensive Cost to produce prototype $10,000 Turning radius 0 ft. Able to fit in tight places Width 30 in. Length 30 in. Exelon Nuclear Runs on one standard outlet Power draw 2400 W Doesn't tip over Tip angle 30 deg. Move quickly Speed 1.5 in/sec. Low maintenance Repair time 30 min. Deploy time 30 min. Easy to handle Weight 1000 lbs.

9 Ranked Metrics 6% 15% 27% 15% 19% 18% Performance Size Labor Cost Weight Power Draw Metric Groups Performance Size Labor Metric Metric Weight (%) Area of shield Turning radius 5.68 Tip angle 5.47 Speed 4.97 Width Length 8.59 Repair time Deploy time 7.08 Group Weight (%) Cost Cost Weight Weight Power Draw Power Draw

10 Benchmarking Robot from Redzone Industrial car Frame Weight: 900lb Weight: ~300lb Cost: $3,093 Cost: $20,000-50,000 Radio Shack Security Camera Controls from Redzone Portable Lead Shield Weight: 5lb Cost: $160 Cost: ~$5,000 Cost: $499

11 Concept Generation Fold up Double fold Single fold

12 Concept Selection 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Electric Single Swing Double Swing Sliding Fixed Folding Single Support Scaffolding

13 Preliminary Design

14 Feasibility Models Hallway Model Tip Model Mounting Model

15 Design Sub-Assemblies Lead support frame Drive system Base Sight system

16 Lead Support Frame Steel Selection: Center Load: 240lbs. X Nf of 2=480 lbs. Side Load: 120lbs. X Nf of 2=240 lbs. Minimum steel size required at load (Square Tube Stock): 1.25 x wall thickness Based on low steel cost and allowable weight increase steel selected: 1.5 x wall thickness Allows for an increase maximum allowable load to of: Center: 800lbs. Side: 220lbs. Note: Calculations based on stress analysis of both the side and the center frame assembly

17 Drive System Motors Weight (lbs.) Surface Force (lbs.) 700 Smooth Bricks Starting at a door jam > Smooth 29 Axial Loads T=N f Fr T=180in-lbs.

18 Base

19 Sight System

20 Complete Assembly

21 Fabrication

22 Testing and Analysis Metrics Target Values Measured Values Area of shield 16 sq. ft sq. ft. Cost to produce prototype $10,000 $6,200 Turning radius 0 ft. 0 ft. Width 30 in in. Length 30 in. 30 in. Power draw 2400 W 1200 W Tip angle 30 deg. 10 deg.* Speed 1.5 in/sec. 6 in./sec. Repair time 30 min. 60 min. Deploy time 30 min. 45 min. * Not tested beyond this value

23 Budget System Description Predicted Cost Qty Predicted Total Cost Predicted Total Actual Total Cost Updated Predicted Total Steel, Hollow Square Stock, 6' $20 6 $120 $47 Frame System Welding, 1 hour $25 5 $125 $355 $0 $152 Miscellaneous $110 1 $110 $105 1/4 HP DC Gearmotor $300 2 $600 $757 Drive System Motor speed controls $600 1 $600 $502 $2,050 Drive train (chain, gears, etc.) $300 2 $600 $1,019 $2,778 Miscellaneous $250 1 $250 $500 Base Metal framework $600 1 $600 $323 $650 Miscellaneous $50 1 $50 $0 $323 Cameras $300 2 $600 $298 Rotating camera mounts $300 2 $600 $210 Sight System Lights $100 2 $200 $40 $2,400 Camera controls $200 2 $400 $0 $1,218 Monitor $350 1 $350 $118 Miscellaneous $250 1 $250 $552 Prototyping Unexpected prototyping expenses $2,000 1 $2,000 $2,000 $1,303 $1,303 Error Unexplained expenses $0 $0 $0 $419 $419 Grand Total $7,455 $6,191 Estimated labor time: 800 Man-hours

24 Hand-off and Completion Final Tuning Operator s Manual Parts List Customer Training Final Report

25 Questions?