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1. Approaching Multisensor Inspection and
Robotic Systems for Dry Cask Storage
ISFSI at Palo Verde
1
C.J. Lissenden
SFWST Meeting
Las Vegas, Nevada
May 23, 2017
This research is being performed using funding
received from the DOE Office of Nuclear Energy's
Nuclear Energy University Programs.

2. 2
Canister NDI
Cliff Lissenden
Sungho Choi
Hwanjeong Cho
Penn State
Engng Sci Mech
Matt Lindsey
Struct Integrity Assoc
Overpack NDI
John Popovics
Homin Song
Illinois
Civil Engng
Surface Composition
Igor Jovanovic*
Xuan Xiao
Penn State
Nuc Engng
*Michigan
Surface Composition
Arthur Motta
Samuel Le Berre
Penn State
Nuc Engng
Robotic Delivery
Sean Brennan
Bobby Leary
Ian Van Sant
Jen Bracken
Penn State
Mech Engng
Delivery and Data
Karl Reichard
Mike Zugger
Penn State
Appl Research Lab
Modeling
Travis Knight
Ryan Priest
Kyle Singer
South Carolina
Nuc Engng
Task
Teams

3. 3
Technical Point of Contact
Steve Marschman, INL
Advisory Board
Dwight Clayton, ORNL
John Scaglione, ORNL
Ryan Meyer, PNNL
Harold Adkins, PNNL
Jeremy Renshaw, EPRI
Ravi Kota, Holtec International

4. Problem: dry storage casks designed for intermediate
storage must provide extended storage and be certified
Aging Management Programs are now required for ISFSIs
Casks were not designed with inspection in mind
Concerns: CISCC and more
conducive
environment
sensitive
material
driving
force
SCC
4
Stainless
Steel

5. Inspection System Design Premises:
• SCC is more likely to occur in HAZ of welds
• Cracks could be oriented transverse or parallel to weld
• Chlorides in solution represent a corrosive environment
• Cask lid removal is undesirable, so inspection system will enter
through exhaust vents
• Environment (Temp & Rad) hard on electronics
• Need to know where data comes from
• Do not lose parts or abandon system in a cask
5
We don’t really know how the system will be used,
that will be dictated by the ISFSI operators and regulators,
so multi-functionality is useful.

6. Sensing systems can function for any welded stainless
steel canister system (vertical or horizontal).
• LIBS for presence of chlorides on canister
• EMATs for shear horizontal wave-based crack inspection of weld
lines
• Thermocouple probe for canister surface temperature
• Geiger-Mueller tube for gamma radiation dose
6
The sensor train is modular so eddy current arrays,
inspection cameras, etc. could easily be delivered.
The delivery system is designed specifically for the
HI-STORM 100S family.

7. A
A
C
B 7
Canister temperature and dose depend on burn-up of fuel
assemblies and time in pool, and decrease over the
storage duration.
• As canister cools, salts could deliquesce on canister
• Robotic inspection system spec-ed for 350F (177C) and 27 krad/h
• Limited access to canister surface
~2”x8” gap

8. 8
Maximum temperature depends on cooling time and
burnup. Temperature varies axially and circumferentially.

9. 9
Sensing and delivery systems are highly integrated for
inspection tasks.

10. 10
Robotic delivery design
philosophy:
• make as passive as possible by
keeping electronics outside
• design it to not get stuck
(wedging/jamming analysis)
• track location of robot to
enable return to an anomalous
measurement site
• leave no trace
Team conducting tests at
Holtec Manufacturing
Division

11. 11
The vent mount attaches the delivery arm and winch to
the exhaust vent opening.
Functionality: 4-bar linkage locks it into place manually
Geometry: designed for HI-STORM 100S and 100S version B vents
Materials: aluminum, peek rollers
NOTE: Prototypes shown in photos are not necessarily
made from the final material

12. 12
The delivery arm on the MPC lid positions the sensor train
above gap between guide channels.
Functionality: pivot provides 90o range of motion, garage for sensor
train, anchors lock on rim of lid, hump assists train launch, camera
Geometry: designed for manual insertion into HI-STORM 100S and
100S version B
Materials: steel, wire cables, peek

13. 13
The sensor train delivers sensors to inspection sites by
traveling down and then back up between guide channels.
Functionality: 3 cars with cargo bays, air cooling, pneumatic
actuation of sensors and stabilizing arm, LEDs, cameras, tether
Geometry: fits between guide channels, 1.5x5.75x6.5 in cargo bay
Materials: aluminum housing, peek wheels

14. 14
The sensor cars deliver EMATs, LIBS, TC, and GM remote
sensing systems.

15. 15
The winch is mounted outside the vent by the vent mount.
Functionality: lower and raise sensor train, encode position of
sensor cars
Geometry: connect to vent mount

16. 16
LabVIEW routines exchange time, position, and status
information between subsystems.

17. 17
Software
• ROS communications implemented
• Thermocouple interface code finished
• Geiger pulse counter code finished
• NTP synchronization code preliminary test complete
Hardware
• First prototype PCB in hand, testing underway
• Thermocouple ADC proven
• Geiger counter tested using frequency generator,
pending Geiger integration test
• Design, 3D print enclosure upon completion of testing
The vent interface system relies on
the BeagleBone and ARL boards.

18. A 3D printed holder is used to form the remote optics in
the robotic sensor car.
Laser
Plasma Plasma
Laser
Functionality: directs light to MPC surface and plasma into optical
fiber, pneumatic extension/retraction
Geometry: housed in car 2
Materials: glass lenses and mirrors, optical fiber, peek housing
18

19. Intensity(arb.u.)
3000
500
750
1000
1250
1500
1750
2000
2250
2500
2750
Wavelength (nm)
842832 833 834 835 836 837 838 839 840 841
Mutipeak fit
Background
Spectrum
The LIBS portable DP setup and remote optics design show
high sensitivity for direct Cl detection – target 0.05-10 g/m2
Optical
fibers
Sample
Final
optics
3D
printer
Cl I
Fe I
10 mg/m2
Laser head
Laser
power
supply
Optical
fiber
Portable DP setup
19

20. We are working on a systematic parameter study of
the portable DP LIBS setup.
Preliminary results from sample with Cl concentration of 1000 mg/m2
Multipeak Fit of Spectrum
Z:xuan On My MacBox SyncSpring 2017
Spring 2017 research21APR parameter
Parameter file
...Parameter map
Parameter map file
Z:xuan On My MacBox Sync
Spring 2017...isParameter study
Converted format1000mg
ParameterStudy-InterpulseDelay
800ns-GateDelay 300ns-Sample#1
File selected
Z:xuan On My ...1000mg
Data in converted format
Z:xuan On My MacBox SyncSpring 2017
Spring 2017 research21APR parameter
Wavelength file
1
Select file
Error
11000
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Wavelength (nm)
844826 828 830 832 834 836 838 840 842
Mutipeak fit
Background
Spectrum
status
0
code
source
Error
0.947878
R-square
Fit
Lorentzian
Fit modelFilter
0.45
high cutoff freq
0
f value
0.500669
FWHM
749.479
Area
838.716
Wavelength
0.53469
FWHM
3510.38
Area
837.659
Wavelength
Fitted parameters
Fe ICl I
Parameter map
1
# of positions for averageMap
300 600 900 1200
800 3510.38 1872.51 200.104 327.416
850 2582.3 1872.04 492.773 346.305
900 2283.7 1511.63 881.747 293.66
950 2228.63 753.417 0 272.373
1000 1489.22 720.823 255.885 110.247
1050 806.818 755.075 582.296 605.384
00
0
Data for parameter map
Penn State & UMich
2017
Parameter Study for NEUP IRP Project
3510.38
0.00
1755.19
2700
300
780
1260
1740
2220
Interpulse delay (ns)
1250800 890 980 1070 1160
Automatically
Peak detection option
837.66
Wavelength
0
WavelengthWavelength
0
AreaArea
0
FWHM
3891.93
Area
0.64
FWHM
Cl I
838.64
Wavelength
0
Wavelength
0
AreaArea
0
FWHM
1158.01
Area
0.67
FWHM
Fe I
Initial guess of parameters3
# of peak
20

21. 21
Mounting holes
BNC Connector (for
use outside robot)
Hi Temp
Epoxy
Al Housing
Periodic permanent magnet EMATs use the Lorentz force
for noncontact transduction, but with zero liftoff.
Functionality: send ultrasonic guided waves (SH) that reflect from
cracks, pneumatic extension/retraction
Geometry: housed in car 1 in a sliding bracket
Materials: Neodymium magnets, flexible PCB, alum

22. The capability of the EMATs to detect notches from
various distances has been determined.
22
0.42"
0.21"
0.03125"
Material: SS 304 Plate thickness: 16 mm (0.625 in)
Semi-elliptical notch 0.42” x 0.21” x 0.03125”
Minimum size targeted

23. B-scan results indicate the distance between EMAT
and notch for perpendicular and parallel orientations.
23
 Perpendicular notch  Parallel notch
Detectable from 4-15” away Detectable from 4-8” away

24. While the sensor train is constrained to travel in the gaps
between guide channels, it can inspect all weld lines.
24

25. 28
Two NEUP IRP milestones remain:
1. benchmark canister NDI system
2. final technology demo
Key remaining tasks include:
• Benchmark EMAT methods at PNNL in
June
• Construct full scale mockup at Penn
State in July
• Test robotic inspection system mobility
at Holtec in early September
• Final technology demo with positive
indications at Penn State in late
September (26th)

26. 29
In conclusion, we are approaching robotic inspection
capabilities for dry storage casks.
Intensity(arb.u.)
3000
500
750
1000
1250
1500
1750
2000
2250
2500
2750
Wavelength (nm)
842832 833 834 835 836 837 838 839 840 841
Mutipeak fit
Background
Spectrum
Cl I
Fe I
10 mg/m2
THANKS!
QUESTIONS?