ML20309A978

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Enclosupresentation
ML20309A978
Person / Time
Site: 07109377
Issue date: 10/13/2020
From:
Orano TN Americas
To:
Office of Nuclear Material Safety and Safeguards
PSaverot - NMSS/DFM/STLB - 301.415.7505
Shared Package
ML20309A976 List:
References
Download: ML20309A978 (42)
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Text

TN-32B High Burnup (HBU)

Demonstration Cask NRC Docket 71-9377 13 October 2020

2 Agenda

Introductions

Meeting Objectives Structural Evaluation - Design Changes, LS-DYNA IL Preliminary Results Thermal Evaluation - Preliminary Results with Increased Decay Heat Containment Evaluation - TLA Seal Leakage Rate Test Shielding Evaluation - Preliminary Results for Transportation Criticality Evaluation - Preliminary Results w/ Burnup Credit Applied Update of Planned Shipping Date Planned Schedule for License Application Questions TN-32B HBU Demonstration Cask NRC Mtg, 3-24-2020

3 Meeting Objectives Discuss Update of TN-32B HBU Demonstration Cask Design for Transport Discuss Preliminary Evaluation Results for:

Structural Thermal Containment (Thermocouple Lance Lateral Seal Leakage Rate Test)

Shielding Criticality Discuss Update of Planned Shipping Date Discuss Schedule for Submittal of Application TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

4 Structural Evaluation - TN-32B HBU Demonstration Cask Design Metallic, Welded Constructed Storage/Transport Cask Maximum Gross Weight (Updated): 272,231 lbm Overall Dimensions (Updated): 144 inch x 263.2 inch length 1.5-inch thick inner containment shell and bottom plate 4.5-inch thick closure lid containment plate w/ 6-inch thick welded shield plate 8-inch thick outer shield forging surround containment shell 8.75-inch thick shield plate covering bottom containment plate 4.5-inch thick neutron shield surrounding outer shield forging Impact limiters installed on each end Same design, including redwood & balsa wood, as utilized on licensed TN-40 & TN-68 casks Modified Closure Lid Thermocouple lance assemblies installed through lid HBU Payload Spent nuclear fuel assemblies with burnup greater than 45 GWd/MTU Four different cladding types: (18) M5', (12) ZIRLO', (1) Zr-4, and (1) Low-Sn Zr-4 Six (6) Poison Rod Assemblies (PRAs) installed for criticality control TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

5 Structural Evaluation - TN-32B HBU Demonstration Cask Design Changes Design Changes Derived from Previous Pre-Application Meetings Inputs from NRC staff Suggested/requested changes from DOE and Orano Lance Cover Plate Design Change Revised design incorporates spacer support bars and 1-inch thick lance cover plate into a single part

  • Simplifies installation
  • Thru hole in plate replaced with a curved slot for routing lance cable/OP tubing
  • Welded to the surface of lid with staggered fillet welds
  • Reduces welding operation with associated reduction in operator dose
  • Provides simplified method to wrap and secure the lance cable and OP tubing for transport Puncture Resistant Plate Design Change Thickness reduced from 2 inches to 13/4 inches to accommodate revised lance cover plate Overall thickness of all plates over lance assemblies increased from 3 inches to 3.88 inches Increased thickness/configuration provides additional shielding to operators and resistance to puncture of thermocouple lance assemblies TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

6 Structural Evaluation - TN-32B HBU Demonstration Cask Design Changes (cont)

Revised Lance Cover Plate Design, Type 304 Stainless Steel Top View Bottom View TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

7 Structural Evaluation - TN-32B HBU Demonstration Cask Design Changes (cont)

Installation Mock-up of Revised Lance Cover Plate Design TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

8 Structural Evaluation - TN-32B HBU Demonstration Cask Design Changes (cont)

Revised Lance Cover Plate Design Installed on Lid TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

9 Structural Evaluation - TN-32B HBU Demonstration Cask Design Changes (cont)

Cross-Section of Revised Lance Cover Plate/Puncture Resistance Plate for Postulated HAC Puncture Bar Impact Directs postulated puncture bar impact load into closure lid TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

10 Structural Evaluation - Preliminary Results Similarity of TN-32B HBU Demonstration Cask with TN-40 cask Overall dimensions: 144 inch x 262 inch (TN-32B) vs. 144 inch x 261 inch (TN-40)

Cavity dimensions: 68.8 inch x 163.4 inch (TN-32B) vs. 72.0 inch x 163 inch (TN-40)

Payload: (32) PWR fuel assemblies (TN-32B HBU) vs. (40) PWR fuel assemblies (TN-40)

Gross weight: 272.2 kips (TN-32B HBU) vs. 271.5 kips (TN-40)

Due to similarity, TN-32B HBU cask response bounded by TN-40 impact limiter response Development of LS-DYNA Model Modelled to represent TN-40 1/3-scale impact limiter (IL) test article Utilized to predict accelerations and impact limiter deformations for multiple orientations Rigid body cask deflection assumed to maximize impact limiter deformations Results scaled for full-sized cask TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

11 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Cask Model TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

12 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Model Results for HAC Warm Side Drop Deformation TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

13 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Model Results for HAC Warm Side Drop Acceleration TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

14 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Model Results for HAC Cold Slapdown Deformation TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

15 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Model Results for HAC Cold Slapdown Acceleration TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

16 Structural Evaluation - Preliminary Results (cont)

LS-DYNA Model Sample Results - HAC Acceleration Summary TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020 Free Drop Case TN-32B HBU Cask Scale Model TN-32B HBU Cask Full Scale TN-40 IL Test HAC Warm (100 °F Ambient) Side 149.6g 49.9g 57g HAC Cold -20 °F Ambient Slapdown (Secondary Impact) 144g 48.0g 61g (Transverse + Rotational)

17 Thermal Evaluation - Preliminary Results Thermal Model of TN-32B HBU Cask Developed Using ANSYS Representing cask structural and thermal capabilities Includes decay heat load of 25.84 kW for earliest shipping date Cask modeled as a full-height, 180-degree representation Impact limiter wood modeled as a homogenized region containing bounding material properties Appropriate conservative assumptions applied, e.g., gaps, reduction in thermal conductivity of materials, etc.

Model utilized to evaluate NCT and HAC conditions

  • Free drop and puncture drop deformation/damage included in HAC model Analysis Results All components do not exceed their respective temperature limits for worst-case NCT hot (100 °F ambient) condition
  • Maximum containment seal temperature: 227 °F (lowest limit 669 °F)
  • Maximum radial neutron resin temperature: 293 °F (limit 300 °F)

All components do not exceed their respective temperature limits during or following HAC fire event

  • Maximum containment seal temperature: 279 °F (lowest limit 669 °F)

TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

18 Thermal Evaluation - Preliminary Results (cont)

ANSYS Thermal Model Results for NCT Hot (100 °F Ambient) Condition TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

19 Thermal Evaluation - Preliminary Results (cont)

ANSYS Thermal Model Results w/ Initial Hot NCT Conditions for End of HAC Fire TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

20 Containment Evaluation - Thermocouple Lance Assembly (TLA) Lateral Slide Test

Purpose:

To address postulated lateral movement of assembly due to side impact per §71.73(c)(1) from 9-meter (30-foot) free drop Two Objects of Test Determine maximum lateral force to initiate sliding of lance body/metallic seal Determine leak tightness of metallic seal if sliding occurs Utilized prototypic lance assembly, metallic O-ring seal and a modified penetration sleeve Perform both pre-and post-test leakage rate tests on complete assembly, i.e., lance body, OP tubing, lance sheath TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

21 Containment Evaluation - TLA Lateral Slide Test (cont)

Photograph of Test Setup w/ Helium MSLD (on left)

TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

22 Containment Evaluation - TLA Lateral Slide Test (cont)

Pre-Test Conditions TLA and penetration sleeve preheated to 230 °F (bounds predicted NCT lid temperature)

TLA biased towards the top of penetration sleeve Jacking screws tightened to specified 60-70 lbf-ft torque

  • Minimum compressive load of 72.57 kips on assembly Pre-Test Leakage Rate of TLA Leakage rate tests performed in accordance with ANSI N14.5-2014 Test utilized gas filled envelope setup, i.e., helium gas surrounding evacuated cavity Helium MSLD connected to OP tubing Established response time of 37 minutes for TLA TLA leakage rate measured as 2.3 x 10-12 ref-cm3/sec Displacement limit set to 0.65 inches for tensile/compression machine TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

23 Containment Evaluation - TLA Lateral Slide Test (cont)

Load-Deflection Curve for Test TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020 0

2.5 5

7.5 10 12.5 15 17.5 20 22.5 25 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 Applied Force (kips)

24 Containment Evaluation - TLA Lateral Slide Test (cont)

Photograph of Damage to Penetration Sleeve Sealing Surface TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

25 Containment Evaluation - TLA Lateral Slide Test (cont)

Test Results Compressive force ~10.8 kips on lance body prior to initiation of sliding Maximum force of 24.23 kips at the maximum 0.65 inch displacement Post-Test Leakage Rate Test Helium MSLD connected to evacuate cavity Vacuum could not be established, indicating presence of a leak path Jacking bolts checked to ascertain any loss of compression Top three bolts slightly loose, which were re-tightened Second attempt to evacuate cavity not successful Proceeded to disassemble test unit for inspection Post-Test Inspection Results Damage to several interfacing surfaces were noted:

  • Edge of stainless steel lance body
  • Outer (non-containment) O-ring seal TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

26 Containment Evaluation - TLA Lateral Slide Test (cont)

Measurements of Penetration Sleeve Sealing Surface Damage TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

27 Containment Evaluation - TLA Lateral Slide Test (cont)

Photograph of Damage to Lance Body Edge & Outer O-ring Lower right quadrant TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

28 Containment Evaluation - TLA Lateral Slide Test (cont)

Close-up Photograph of Outer O-ring Damage TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

29 Containment Evaluation - TLA Lateral Slide Test (cont)

Test Objective 1: Max Lateral Force to Initiate Sliding of Lance Body/Metallic Seal Test demonstrated TLA remains stationary until a significant lateral force is applied Test recorded maximum applied force of ~10.8 kips prior to sliding Lance body weight: ~11 pounds Required side drop impact to overcome compressive friction to initiate movement

  • 10,800/11 = ~1,000g
  • Assuming a worst-case dynamic load factor of 2.0, required side impact ~500g
  • Actual maximum HAC impact from 30-ft free side drop < 50g TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

30 Containment Evaluation - TLA Lateral Slide Test (cont)

Test Objective 2: Determine Leak Tightness of Metallic Seal If Sliding Occurs Objective not achieved due to sealing surface/seal damage Factors Resulting in Sealing Surface/Seal Damage

  • Sliding contact area was only partial (approximately 22%) of total circumferential area
  • Upper three jacking screws lost some of their preload
  • Lower edge of stainless steel lance body scored stainless steel sealing surface
  • Adjacent outer O-ring slid over damaged sealing surface, damaging softer silver jacket
  • Lack of damage to inner (containment) O-ring (0.404 inches from outer O-ring) indicates lack of contact with damaged sealing surface Based on this evidence, the lance body tilted towards bottom during test
  • Most likely due to penetration sleeve sealing surface not being parallel to vertical axis of test machine Sealing surface/seal damage not representative of lance body sliding due to a side impact TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

31 Containment Evaluation - TLA Lateral Slide Test (cont)

Test Result Conclusions TLA is significantly more leaktight than ANSI N14.5 requires (10-12 vs. 10-7)

Non-credible lateral force required to initial sliding of lance body TLA will survive postulated §71.71 and §71.73 free and puncture drops with no loss of containment function TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

32 Shielding Evaluation - Preliminary Results Shielding Model of TN-32B HBU Cask Developed Using MCNP5v1.60 Source term developed utilizing ORIGEN-ARP module of SCALE 6.1 and ENDF/B-VII nuclear data cross-section library Source calculation adjusted initial enrichment by -0.05 wt% to account for uncertainties in batch enrichment Average power of assemblies increased by 2.5% to account for burnup uncertainty Axial burnup distributions for MCNP gamma and neutron sources are for >46 GWd/MTU fuel from NUREG/CR-6801 TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

33 Shielding Evaluation - Preliminary Results (cont)

Elevation View of MCNP Shielding Model TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

34 Shielding Evaluation - Preliminary Results (cont)

Cross-Sectional View of MCNP Shielding Model TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

35 Shielding Evaluation - Preliminary Results (cont)

NCT Dose Rates (mrem/hr)

TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

36 Shielding Evaluation - Preliminary Results (cont)

HAC Dose Rates (mrem/hr)

TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

37 Criticality Evaluation - Preliminary Results with Burnup Credit Applied Criticality Model of TN-32B HBU Cask Developed Using SCALE 6.1.3 Utilized ORIGEN-APP libraries developed in shielding calculation Burnup loading curve generated for various BECT combinations in STARBUCS module of SCALE 6.1.3 Utilized NRC ISG-8 recommendations for including nuclides for burnup credit Code bias and bias uncertainty for major actinides calculated using Haut Taux de Combustions (HTC) experimental data supplemented by applicable MOX critical experiments Assumed radial neutron shield and outer steel shell are removed, and infinite array of closely packed casks with moderator in interstitial spaces Modeled (9) sister rods removed from two assemblies as stainless steel rods Included (6) poison rod assemblies (PRAs) installed in specific assemblies Upper Subcritical Limit (USL) for HBU Payload Calculated for most reactive fuel configuration USL = 0.90874 TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

38 Criticality Evaluation - Preliminary Results with Burnup Credit Applied (cont)

View of SCALE 6.1.3 Model Basket Cross-Section w/ (6) PRAs TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

39 Update of Planned Shipping Date Previously Planned Shipping Date Cask loaded and placed in storage on North Anna Power Station (NAPS) ISFSI pad in November 2017 Transport off-site following 10 years storage period Earliest ship date set for July 1, 2027 Maximum decay heat load for 2027 transport is 23.52 kW with a maximum 0.787 kW for any assembly Following additional discussions with stakeholders (DOE, EPRI, Dominion), desire to be prepared to transport off-site earlier than July 2027 Earliest ship date advanced to October 1, 2023 Transport off-site following 5.87 year storage period Slightly increases maximum decay heat load to 25.84 kW with a maximum 0.878 kW for any assembly No other programmatic changes contemplated for off-site transport TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

40 Planned Schedule for License Application Calculations and SAR chapters in process to support submittal Submittal of SAR to NRC in late 4th quarter 2020 Receipt of NRC Requests for Additional Information (RAIs) in 3rd quarter 2021 Receipt of NRC Certificate of Compliance in 2nd quarter 2022 License application submittal to support planned transport as early as October 2023 Planned pre-transport activities:

Fabrication of impact limiters, transportation skid, and auxiliary equipment Transportation planning from NAPS to a site to be identified later TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

41 Questions?

TN-32B HBU Demonstration Cask NRC Mtg, 10-13-2020

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