60. june pnnl sister pin test plan hanson

1. Used Fuel Disposition Campaign
Peak Cladding Temperatures:
Conservative Licensing Approach vs. Actual
Brady Hanson, Lab Lead Experiments
Pacific Northwest National Laboratory
NEI Used Fuel Management Conference
May 3, 2016
Orlando, FL
PNNL-SA-117853

2. Used
Fuel
Disposition
Conservatisms in Thermal Analysis
 Thermal models
 Ambient condition assumption
 Duration of blowdown and drying
 Design-basis loading vs actual loading
 Assembly decay heat calculations
2

3. Used
Fuel
Disposition
“Best Estimate” Model vs.
Conservative Model
For Project Research Cask (TN-32B)
 337°C Peak Cladding Temperature (PCT) (drying steady state)
compared to ~350°C semi-conservative model used for licensing
3
Fort JA, JM Cuta, SR Suffield, and HE Adkins. 2016. Thermal Modeling of Proposed TN-32B Cask for High Burnup Fuel Storage Demonstration Project.
FCRD-UFD-2015-000116, PNNL-24549 Rev. 1. Prepared for the U.S. Department of Energy Used Fuel Disposition Campaign, Washington, D.C.

4. Used
Fuel
Disposition
Ambient Temperature
 Typically assume ambient temperature
of 100°F average daily temperature
 Data from Hanford, WA
– High temperature 113°F (1961, 2002, 2006)
– 2015 had 28 days above 100°F (same as
1958)
 Effect of ambient temperature on PCT in
canister systems is greater than in bare
fuel casks
4
Date Max (F) Min (F) Ave (F)
26-Jun 106 66 86
27-Jun 110 71 90
28-Jun 111 80 96
29-Jun 105 82 94
30-Jun 103 76 90
1-Jul 102 74 88
2-Jul 107 77 92
3-Jul 108 71 90
4-Jul 106 75 90
5-Jul 100 77 88
6-Jul 103 70 86
7-Jul 102 74 88
8-Jul 103 75 89
9-Jul 105 68 86
10-Jul 101 72 86

5. Used
Fuel
Disposition
Effect of Ambient Air Temperature
on PCT
Condition Steady State PCT (°C)
Transfer at -3°F (-19°C) 351
Transfer at 103°F (39°C) 394
Storage at -3°F (-19°C) 285
Storage at 70°F (21°C) 314
Storage at 103°F (39°C) 327 5
PNNL COBRA-SFS Modeling of
HI-STORM 100 at Diablo Canyon
AREVA TN Calculation for
NUHOMS 32P (21.12 kW)
Design Basis for Calvert Cliffs

6. Used
Fuel
Disposition
Example of Transient Drying Curve
6
Peak Cladding Temperature for MAGNASTOR at Design Basis Loading (35.5 kW)
Drying Time (hrs)
0 5 10 15 20 25
PeakCladdingTemperature(C)
0
50
100
150
200
250
300
350
400
338 C
Data courtesy of NAC International

7. Used
Fuel
Disposition
Actual Drying Times
7
Data from Calvert Cliffs Response For RAI#E-3, Calvert Cliffs Nuclear Power Plant, LLC, April 24, 2013.

8. Used
Fuel
Disposition
Variable Drying Times and Decay
Heat Load MAGNAATOR
 ZionSolutions Campaign
 61 MAGNASTOR 37 PWR
 Decay heat load
– 10.5 – 18.4 kW
– 30% - 52% of design basis
 Drying times
– 9 – 91 hours
– Function of poison
material and procedure
 Catawba ~18 hrs for
~30 kW (85%)
8George Carver, NAC International, Drying Process Efficiency for Used Fuel Storage Campaigns, presented at the 2015 NEI Used Fuel
Management Conference, Orlando, FL

9. Used
Fuel
Disposition
Variable Decay Heat Loading
NUHOMS 32P
Decay Heat Load (kW) PCT (°C)
23.04 273
25.6 291
29.6 311
 Recent experience at Calvert Cliffs
 Design Basis 21.12 kW
 Actual 11.53 – 18.62 kW (55% - 88%)
9
PCT under steady-state vacuum drying operations in helium for NUHOMS 32 PHB DSC

10. Used
Fuel
Disposition
Margin to 400°C for 24 NUHOMS
32P DSCs loaded at Calvert Cliffs
 One canister had
an extended
transfer time so
PCT calculated to
be <394°C, the
PCT for design
basis (21.12 kW)
heat load during
transfer.
 Actual heat load
was 18.3 kW
(87%)
10
Calvert Cliffs Response For RAI#E-3, Calvert Cliffs Nuclear Power Plant, LLC, April 24, 2013.

11. Used
Fuel
Disposition
Variable Decay Heat Effect on PCT
During Vacuum Drying in Research
Project Cask (TN-32B)
11
Fort JA, JM Cuta, SR Suffield, and HE Adkins. 2016. Thermal Modeling of Proposed TN-32B Cask for High Burnup Fuel Storage Demonstration Project.
FCRD-UFD-2015-000116, PNNL-24549 Rev. 1. Prepared for the U.S. Department of Energy Used Fuel Disposition Campaign, Washington, D.C.

12. Used
Fuel
Disposition
Conservatisms in Assembly Decay
Heat Calculations
Measured Decay Heat (W)
0 200 400 600 800 1000 1200 1400 1600 1800
CalculatedDecayHeatRG3.54(W)
0
200
400
600
800
1000
1200
1400
1600
1800
 Reg Guide 3.54
methodology
– Is always conservative
(higher decay heat than
actual/measured)
– PWR Range 6.8% - 17.2%
– PWR average 12.5%
– PWR median 12.9%
– BWR Range 3.7% - 55.3%
– BWR average 22.6%
– BWR median 19.9%
12
Gauld IC and BD Murphy. 2010. Technical Basis for a Proposed Expansion of Regulatory Guide 3.54-Decay Heat Generation in an
Independent Spent Fuel Storage Installation. NUREG/CR-6999. ORNL/TM-2007/231. Prepared for the U.S. Nuclear Regulatory Commission
Office of Nuclear Regulatory Research, Washington, D.C.

13. Used
Fuel
Disposition
High Burnup Data Project
Research Project Cask
13
Industry Calculated Decay Heat (36.8 kW)
1013 1167 1015 909
914 1276 1503 1477 1163 906
885 1496 696 1281 1482 1120
1165 1492 1037 725 1496 1121
1036 1031 1495 1511 1178 1035
1073 1155 1031 918
907 983 909 793
795 1039 1170 1149 977 806
795 1162 463 1047 1152 944
979 1159 918 641 1163 944
929 912 1161 1162 989 915
915 970 922 798
ORIGEN Calculated Decay Heat (30.6 kW)
Percent of Original (83%)
10.5% 15.8% 10.4% 12.8%
13.0% 18.6% 22.2% 22.2% 16.0% 11.0%
10.2% 22.3% 33.5% 18.3% 22.3% 15.7%
16.0% 22.3% 11.5% 11.6% 22.3% 15.8%
10.3% 11.5% 22.3% 23.1% 16.0% 11.6%
14.7% 16.0% 10.6% 13.1%
Peak Clad Temperature (°C)
Peak Clad Temperature (°C)

14. Used
Fuel
Disposition
Summary
 “Best Estimate” thermal models removing known conservatisms
→ ~ 10°C - 20°C+ margin
 Ambient temperature assumption → 0°C - 20°C+ margin
 Actual drying times vs. vacuum steady state asymptote →
0°C - 50°C+ margin
 Actual loading (50%-90%) vs. design basis heat load →
20°C - 50°C+ margin
 Actual vs. conservative assembly decay heat calculations →
20°C - 50°C+ margin
14

15. Used
Fuel
Disposition
Conclusion
It is expected that Peak Cladding
Temperatures are << 400°C regulatory
guidance limit
All (?) < 325°C
Most < 300°C
Many 250°C - 275°C
Need additional data, modeling, and model
validation to verify
15

16. Used Fuel Disposition Campaign
Peak Cladding Temperatures:
Conservative Licensing Approach vs. Actual
Brady Hanson, Lab Lead Experiments
Pacific Northwest National Laboratory
NEI Used Fuel Management Conference
May 3, 2016
Orlando, FL
PNNL-SA-117853