ML20002A069

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SAR-II-8.4 Chapter 5, Operation Systems
ML20002A069
Person / Time
Site: 07200020
Issue date: 12/11/2019
From:
US Dept of Energy, Idaho Operations Office
To:
Office of Nuclear Material Safety and Safeguards
References
CLN200374
Download: ML20002A069 (34)
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Text

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page i TABLE OF CONTENTS

5. OPERATION SYSTEMS....................................................................................................... 5.1-1 5.1 Operation Description...................................................................................................... 5.1-1 5.1.1 Narrative Description of Operations at the TAN Hot Shop................................... 5.1-1 5.1.2 Operations Conducted at the ISFSI........................................................................ 5.1-5 5.1.3 Flowsheets............................................................................................................ 5.1-13 5.1.4 Identification of Subjects for Safety Analysis..................................................... 5.1-13 5.2 Fuel Handling Systems.................................................................................................... 5.2-1 5.2.1 TMI-2 Canister Handling and Transfer.................................................................. 5.2-1 5.2.2 TMI-2 Canister Storage......................................................................................... 5.2-3 5.3 Other Operating Systems................................................................................................. 5.3-1 5.3.1 Operating System................................................................................................... 5.3-1 5.3.2 Component/Equipment Spares............................................................................... 5.3-1 5.4 Operation Support System............................................................................................... 5.4-1 5.4.1 Instrumentation and Control System...................................................................... 5.4-1 5.4.2 System and Component Spares.............................................................................. 5.4-1 5.5 Control Room and/or Control Areas................................................................................ 5.5-1 5.6 Analytical Sampling........................................................................................................ 5.6-1 LIST OF TABLES Table 5.1-1 Instrumentation Used for NUHOMS-12T System Operations............................... 5.1-15 LIST OF FIGURES Figure 5.1-1 Primary Operations for the NUHOMS-12T System............................................. 5.1-16 Figure 5.2-1 NUHOMS Cask/HSM Alignment Verification....................................................... 5.2-4

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TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-1

5. OPERATION SYSTEMS This chapter describes the operations to be performed using the NUHOMS-12T system with the MP-187 transportation cask described in previous chapters and shown on the drawings in Appendix A.

Appendix E describes the operations to be performed using the NRC 10 CFR 72 approved OS-197 Transfer Cask. The major difference between the two transportation approaches is that the NRC 10 CFR 72 approved OS-197 Transfer Cask does not require impact limiters, evacuation and helium backfill of the DSC, leak testing of the DSC closure weld, or installation of the vent/filter housing transportation covers. The operations include preparation of the DSC and fuel loading, closure of the DSC, transport to the ISFSI, DSC transfer into the HSM, monitoring operations, and DSC retrieval from the HSM. The NUHOMS-12T transfer equipment, and the existing systems and equipment are used to accomplish these operations.

As of the effective date of the renewed TMI-2 ISFSI license, a license condition prohibits the use of the MP-187 transfer cask (TC) if that MP-187 cask was fabricated 20 or more years prior to its proposed use at the TMI-2 ISFSI. Unless and until the TMI-2 ISFSI license is amended to remove or suitably modify this license condition, all activities involving the TC described in this FSAR may only be conducted using the OS-197 TC as described in Appendix E of this FSAR. Furthermore, if use of the TC used to retrieve the DSC requires the use of TC spacers, the spacers shall have been fabricated less than 20 years prior to their use at the TMI-2 ISFSI.

Operations are performed in two locations: the TAN Hot Shop and the ISFSI. Handling operations at the TAN Hot Shop are described herein but are not subject to licensing, however certain steps in the TAN procedures implement requirements of the licensed system and these procedure steps are subject to change control under 10 CFR 72.48 (see 9.4.1). Operations at the ISFSI are subject to requirements of 10 CFR Part 72. Procedures are delineated in outline form to describe how these operations are to be performed and are not intended to be limiting. TMI-2 canister and cask handling operations performed at TAN under DOE regulated procedures and operations under the purview of 10 CFR Part 71 are described in less detail. Operational procedures at TAN and procedures for transportation under 10 CFR Part 71 may be revised and new ones may be developed according to INL requirements, provided that the limiting conditions of operation are not exceeded.

5.1 Operation Description The following sections outline the general procedures (sequences of steps) that will be followed to prepare and load TMI-2 canisters into the DSCs, transfer the DSCs from TAN to the ISFSI, and place the DSCs into the HSMs at the ISFSI. Operating procedures will be developed for the NUHOMS-12T system to ensure these sequences are followed to: minimize the amount of time required to complete the subject operations; minimize personnel exposure; and assure that all operations required for DSC loading, closure, transfer, and storage are performed safely. The procedure outlines presented here are provided as a guide for the preparation of the operating procedures and serve to point out how the NUHOMS-12T system operations are to be accomplished. This outline is not intended to be limiting in that DOE-ID may judge that alternate acceptable means are available to accomplish the same operational and safety objectives.

5.1.1 Narrative Description of Operations at the TAN Hot Shop The following steps describe the recommended operating procedures for the NUHOMS-12T system with the MP-187 transportation cask. Figure 5.1-1 provides a

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-2 series of pictorial views of the key loading and transfer operations to help in the description of the operating activities.

5.1.1.1 Preparation of the Cask and DSC

1. Prior to placement in dry storage, the TMI-2 canisters are to be dried to ensure that no free water is contained in the canisters. A verified record of final TMI-2 canister drying will be maintained for each canister.
2. Install lower trunnions on the cask. Place the cask on the turning skid. Install upper trunnions. Upright the cask using a cask handling crane.
3. Place the cask in the vertical position in the TAN Hot Shop using the cask handling crane and the cask rigging.
4. Place scaffolding around the cask so that the top cover plate and surface of the cask are easily accessible to personnel.
5. Remove the cask top cover plate and top spacer. Examine the cask cavity for any physical damage and ready the cask for service.
6. Examine the DSC for any physical damage which might have occurred since the receipt inspection was performed. The DSC is to be cleaned and any loose debris removed Cleaning methods shall not introduce any chemical residues.
7. Verify the unique identification of the DSC and using a crane, lower the DSC into the cask cavity by the internal lifting lugs and rotate the DSC to match the cask and DSC alignment marks.
8. Install temporary covers over the cask/DSC annulus to prevent contamination or debris from entering the annulus.
9. Place the top shield plug onto the DSC. Examine the top shield plug to ensure a proper fit.
10. Remove the top shield plug.

5.1.1.2 TMI-2 Canister Loading into the DSC

1. Remotely load the dry TMI-2 canisters from the canister staging area into the DSC in accordance with the TAN procedures. Remove the TMI-2 canister inlet and drain line caps and remove the quick disconnect fittings, if not already done.
2. During the DSC loading process, check, record, and independently verify the identity and location of each TMI-2 canister in the DSC.
3. Install test flanges on vent and purge penetrations on the shield plug.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-3

4. After all the TMI-2 canisters have been placed into the DSC and their identities verified and recorded, position the cask rigging and the top shield plug and lower the shield plug into the DSC.
5. Visually verify that the top shield plug is properly seated onto the DSC.
6. Decontaminate the cask exterior surface if required. Temporary shielding may be installed as necessary to minimize personnel exposure.

5.1.1.3 DSC Shield Plug Sealing

1. Install temporary shielding to minimize personnel exposure throughout the subsequent welding operations as required.
2. Place the automated welding machine onto the cask. As an alternative manual welding is permissible.
3. Check radiation levels along the surface of the shield plug.
4. Verify that the cask/DSC annulus cover is in place to prevent debris from entering the annulus.
5. Take appropriate measures to assure that concentrations of flammable gases are below the flammable limit, or sample the environment in the DSC for flammable gases before welding.
6. Obtain authorization to proceed and then ready the automated welding machine, if installed, and tack weld the shield plug to the DSC shell.

Complete the 360° continuous shield plug weldment and remove the automated welding machine, if installed.

7. Perform surface examination of the shield plug welds (one continuous 360° shield plug to DSC shell weld, one purge penetration weld) in accordance with the Technical Specification requirements.
8. Connect the vacuum drying system (VDS) to the DSC purge port as shown in Figure 4.7.1.
9. Connect the hose from the purge test port to the intake of the vacuum pump.

Connect a hose from the discharge side of the VDS to an off-gas system.

Connect the VDS to a helium source.

10. Open the valve on the suction side of the pump, start the VDS and draw a vacuum on the DSC cavity. When the pressure reaches 10 torr or less, the DSC evacuation is complete. This step is performed to provide an evacuated DSC so that when backfilled with helium, the helium is not diluted with air.
11. Open the valve to the purge port and allow the helium to flow into the DSC cavity.
12. Pressurize the DSC with helium to 22 psia.

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13. Helium leak test the shield plug to DSC shell weld for leakage. This leak test is performed for informational purposes prior to welding on the top cover plate.
14. If a leak is found, repair the weld, re-pressurize the DSC and repeat the Step 6 surface examination and the helium leak test.
15. If no leak is detected, release the pressure.

5.1.1.4 DSC Top Cover Installation

1. Disconnect the VDS from the DSC.
2. Place the top cover plate onto the DSC. Verify proper fit up of the top cover plate with the DSC shell. Install the automatic welding system on the cask (as an alternative manual welding is permissible).
3. Tack weld the top cover plate to the DSC shell. Install the top cover plate weld root pass. Perform surface examination of the root pass weld. Weld the top cover plate to the DSC shell and perform surface examination on the weld surface in accordance with the Technical Specification requirements.
4. Remove the automated welding machine from the cask, if installed. Remove vent port test cover and manually seal weld the top cover to the shield plug around the vent and purge penetrations. Perform surface examination of the seal welds in accordance with Technical Specification requirements.
5. Remove temporary shielding from the vent port and purge port penetrations.
6. Install the vent and purge filter assemblies (with transportation covers already installed on the filter assemblies) and the double mechanical seals onto the DSC penetrations.
7. Evacuate and backfill the DSC with helium in accordance with 10 CFR Part 71 requirements. Evacuate and leak test the annulus between the double mechanical seal between the DSC and the vent assembly. Test ports are integral to the filter housings. Testing is done in accordance with 10 CFR Part 71 (10 CFR Part 71 requirements bound), however, only the Technical Specifications requirements are required for the 10 CFR Part 72 license.
8. Remove the temporary cask/DSC annulus cover.
9. Rig the cask top cover plate with top internal spacer attached and lower the cover plate onto the transport cask. Bolt the cask cover plate into place, tightening the bolts to the required torque in a star pattern.
10. Leak test the DSC and cask in accordance with the 10 CFR Part 71 requirements and document on the acceptance form.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-5 5.1.1.5 Cask Downending and Preparation for Transport to ISFSI

1. The transport trailer should be positioned so that the cask support skid is accessible with the trailer supported on the vertical jacks.
2. Re-attach the transport cask rigging to the crane hook. Transfer the cask to the turning skid and then downend the cask. Remove cask upper trunnions.

Return the cask to the transport trailer.

3. Remove the cask lower trunnions. Install top half of transport skid frame.

Install impact limiters. Install personnel barriers.

4. Complete applicable transfer forms for the spent nuclear fuel (SNF) contained in the DSC and attach to the acceptance form.

5.1.2 Operations Conducted at the ISFSI 5.1.2.1 DSC Transfer to the HSM

1. HSM Preparation to Receive DSC: Remove the HSM door using a porta-crane, inspect the cavity of the HSM, removing any debris and ready the HSM to receive a DSC. The doors on adjacent HSMs should remain in place.
2. Prior to transfer activities, verify that DSC temperatures are within the control limits of Technical Specifications of the SAR.
3. Using a suitable heavy haul tractor, transport the cask from the TAN facility to the ISFSI along the designated transfer route.
4. Once at the ISFSI, remove the cask impact limiters and complete the receipt records verification.
5. After removing the impact limiters, move the transport trailer to the HSM.
6. Check the position of the trailer to ensure the centerline of the HSM and cask approximately coincide. If the trailer is not properly oriented, reposition the trailer, as necessary.
7. Set the trailer brakes and disengage the tractor. Drive the tractor clear of the trailer.
8. Connect the skid positioning system hydraulic power unit to the positioning system via the hose connector panel on the trailer, and power it up. Remove the skid tie-down bracket fasteners and use the skid positioning system to bring the cask into approximate vertical and horizontal alignment with the HSM. Using optical survey equipment and the alignment marks on the cask and the HSM, adjust the position of the cask until it is properly aligned with the HSM.
9. Secure the cask restraints to the front wall embedments of the HSM.

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10. Unbolt and remove the cask top cover plate and top internal spacer.
11. Using the skid positioning system, fully insert the cask into the HSM access opening docking collar.
12. After the cask is docked with the HSM, verify the alignment of the cask using the optical survey equipment.
13. Install ram front support on base of cask. Position the hydraulic ram behind the cask in approximate horizontal alignment with the cask and level the ram. Remove the ram access cover on the cask. Power up the ram hydraulic power supply and extend the ram through the bottom cask opening into the DSC grapple ring.
14. Activate the hydraulic cylinder on the ram grapple and engage the grapple arms with the DSC grapple ring.
15. Recheck all alignment marks and ready all systems for DSC transfer.
16. Activate the hydraulic ram to initiate insertion of the DSC into the HSM.

Stop the ram when the DSC is fully inserted or if there are indications that the DSC is jammed.

17. Disengage the ram grapple mechanism so that the grapple is retracted away from the DSC grapple ring.
18. Retract and disengage the hydraulic ram system from the cask and move it clear of the cask. Remove the ram support and cask restraints from the HSM.
19. Using the skid positioning system, disengage the cask from the HSM access opening.
20. Install the DSC seismic restraint and record the unique identification number of the DSC and its HSM location.
21. Install the HSM door using a portable crane and secure it in place. Door may be welded for security.
22. Open rear wall access door. Remove transportation covers from the vent and purge assemblies and install the dust covers.
23. Close and lock the rear wall access door.
24. Replace the cask top cover plate and internal spacer. Secure the skid to the trailer, retract the vertical jacks and disconnect the skid positioning system.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-7

25. Reconnect the tractor and tow the trailer and cask to the designated location.

Return the remaining transfer equipment to the designated location.

26. Close and lock the ISFSI access gate and activate the ISFSI security measures.

5.1.2.2 HSM Monitoring Operations

1. Perform routine security surveillance in accordance with the TMI-2 ISFSI physical protection plan.
2. Perform surveillance of the DSC vent system in accordance with the Technical Specification requirements.

5.1.2.3 DSC Retrieval from the HSM

1. Ready the cask, transport trailer, and support skid for service and tow the trailer to the HSM.
2. Prior to retrieval activities, verify that DSC temperatures are within the control limits of Technical Specifications.
3. Open the rear wall access door. Remove the vent system dust covers and install the transportation covers on the vent and purge filter assemblies.

Evacuate and backfill the DSC, with helium (if required for 10 CFR Part 71 transportation testing). Install and leak test (if required for transport) the vent and purge assembly seals and vent and purge assembly transportation cover seals.

4. Back the trailer to within a few inches of the HSM, remove the cask top cover plate and top internal spacer.
5. Remove the HSM door using a porta-crane. Remove the seismic restraint.
6. Connect the skid positioning system hydraulic power unit to the positioning system via the hose connector panel on the trailer, and power it up. Remove the skid tie-down bracket fasteners and use the skid positioning system to bring the cask into approximate vertical and horizontal alignment with the HSM. Using optical survey equipment and the alignment marks on the cask and the HSM, adjust the position of the cask until it is properly aligned with the HSM.
7. Using the skid positioning system, fully insert the cask into the HSM access opening docking collar.
8. Secure the cask restraints to the front wall embedments of the HSM.
9. After the cask is docked with the HSM, verify the alignment of the cask using the optical survey equipment.
10. Install and align the hydraulic ram with the cask.

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11. Extend the ram through the cask into the HSM until it is inserted in the DSC grapple ring.
12. Activate the arms on the ram grapple mechanism with the DSC grapple ring.
13. Retract ram and pull the DSC into the cask.
14. Retract the ram grapple arms.
15. Disengage the ram from the cask.
16. Remove the cask restraints.
17. Using the skid positioning system, disengage the cask from the HSM.
18. Install the internal spacer and cask top cover plate and ready the trailer for transport.
19. Replace the door on the HSM.

5.1.2.4 Removal of TMI-2 Canisters from the DSC If retrieval of the TMI-2 canisters is required, there are two basic options available.

The TMI-2 canisters could be removed from the DSC and reloaded into a shipping cask at a dry transfer facility or at the TAN Hot Shop if available. Procedures for unloading of the TMI-2 canisters into a fuel pool or another cask are presented here. Dry unloading procedures are essentially identical to those of DSC loading through the DSC weld removal. Prior to opening the DSC, the following operations are to be performed.

1. Transfer the cask to the cask handling area inside the TAN or other facility.
2. Position and ready the trailer for access by the crane.
3. Remove the top half of the transportation skid and install lower trunnions.
4. Move cask to turning skid.
5. Install upper trunnions.
6. Move the crane backward in a horizontal motion while simultaneously raising the crane hook vertically and lift the cask off the turning skid.
7. Lower the cask to stand in a vertical position.
8. Clean the cask to remove any dirt which may have accumulated during the loading and transfer operations.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-9

9. Place scaffolding around the cask so that any point on the surface of the cask is easily accessible to handling personnel.
10. Unbolt the cask top cover plate.
11. Connect the rigging cables to the cask top cover plate and lift the cover plate and internal spacer from the cask. Set the cask cover plate and internal spacer aside and disconnect the lid lifting cables.
12. Install temporary shielding to reduce personnel exposure as required.

The process of DSC unloading is similar to that used for DSC loading. DSC opening operations described below are to be carefully controlled in accordance with DSC unloading procedures. This operation is to be performed under established safety and radiological control procedures for welding, grinding, and handling of potentially highly contaminated equipment.

Following opening of the DSC, TMI-2 canisters will be removed using unloading procedures governed by the TAN or other facility operating procedures. The general sequence for these operations are as follows:

13. Place an exhaust hood or tent over the DSC, if necessary. The exhaust should be filtered or routed to the site radwaste system.
14. Vent and purge the gas inside the DSC through the vent port to the facility off-gas system and backfill the DSC with an inert gas such as argon.
15. Remove the DSC vent and purge assemblies and install the vent test penetration and purge port quick disconnect to prevent the spread of contamination.
16. Place welding blankets around the cask and scaffolding.
17. Using plasma arc-gouging, a mechanical cutting system, or other suitable means, remove the seal welds from between the top cover and the shield plug at the vent and purge penetrations. Then remove the weld between the top cover plate and DSC shell. A fire watch should be placed on the scaffolding, as appropriate. The exhaust system should be operating at all times.
18. The material or waste from the cutting or grinding process should be treated and handled in accordance with the plant's low level waste procedures unless determined otherwise.
19. Remove the top of the tent, if necessary.
20. Remove the exhaust hood, if necessary.
21. Remove the DSC top cover plate.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-10

22. Reinstall tent and temporary shielding, as required. Remove the shield plug to DSC weld. Remove any remaining excess material on the inside shell surface by grinding.
23. Clean the cask surface of dirt and any debris which may be on the cask surface as a result of the weld removal operation.
24. Lift the top shield plug from the DSC.
25. Remove the TMI-2 canisters from the DSC and place the TMI-2 canisters into an authorized location or other cask.

5.1.2.5 DSC Transfer to the DSC Overpack The need to transfer a DSC to the HSM with an integral overpack could arise as a result of damage or deterioration that occurs unexpectedly or due to loading difficulties. The following procedural steps accommodate this condition with the initial condition of the DSC already in the transfer cask.

As of the effective date of the renewed TMI-2 ISFSI license, a license condition prohibits the use of HSM-15 and its pre-installed DSC overpack for spent fuel storage operations. Unless and until the TMI-2 ISFSI license is amended to remove or suitably modify this license condition, all activities involving the use of HSM-15 and its pre-installed DSC overpack described in this FSAR are prohibited.

1. Prior to positioning the cask close to the DSC overpack, remove the HSM door using a porta-crane. Inspect the cavity of the DSC overpack, removing any debris, and ready the DSC overpack to receive a DSC. The doors on adjacent HSMs, if any, must remain in place. Verify that the overpack vent and purge filters are in place and the filter housing seals have been leak tested.
2. Prior to transfer operations verify that DSC temperatures are within the control limits of Technical Specifications.
3. Using a suitable heavy haul tractor, move the cask to the ISFSI overpack HSM location.
4. Check the position of the trailer to ensure the centerline of the DSC overpack and cask approximately coincide. If the trailer is not properly oriented, reposition the trailer as necessary.
5. Set the trailer brakes and disengage the tractor. Drive the tractor clear of the trailer.
6. Unbolt and remove the cask top cover plate and top internal spacer.
7. Using the skid positioning system, fully insert the cask into the DSC overpack access opening docking collar.

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8. Connect the skid positioning system hydraulic power unit to the positioning system via the hose connector panel on the trailer, and power it up. Remove the skid tie-down bracket fasteners and use the skid positioning system to bring the cask into approximate vertical and horizontal alignment with the DSC overpack. Using optical survey equipment and the alignment marks on the cask and the DSC overpack, adjust the position of the cask until it is properly aligned with the DSC overpack. Just prior to inserting the DSC into the overpack, pull a vacuum on the DSC, release the vacuum and remove the filters.
9. After the cask is docked with the DSC overpack, verify the alignment of the cask using the optical survey equipment.
10. Secure the cask trunnions to the front wall embedments of the DSC overpack using the cask restraints.
11. Install ram front support on the base of the cask and position the hydraulic ram behind the cask in approximate horizontal alignment with the cask and level the ram. Power up the ram hydraulic power supply and extend the ram through the bottom cask opening into the DSC grapple ring.
12. Activate the hydraulic cylinder on the ram grapple and engage the grapple arms with the DSC grapple ring.
13. Recheck all alignment marks used in the Step 11 operation and ready all systems for DSC transfer.
14. Activate the hydraulic ram to initiate insertion of the DSC into the DSC overpack. Stop the ram when the DSC reaches the support rail stops at the back of the DSC overpack.
15. Disengage the ram grapple mechanism so that the grapple is retracted away from the DSC grapple ring.
16. Retract and disengage the hydraulic ram system from the cask and move it clear of the cask. Remove the ram support and cask restraints.
17. Using the skid positioning system, disengage the cask from the DSC overpack access opening.
18. Install the DSC overpack cover including surface examination of the root and final pass of the weld in accordance with Technical Specification requirements.
19. Install the HSM door using a portable crane and secure it in place. Door may be welded for security.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-12

20. Replace the cask top cover plate. Secure the skid to the trailer, retract the vertical jacks and disconnect the skid positioning system.
21. Tow the trailer and cask to the designated location. Return the remaining transfer equipment to the designated location.
22. Close and lock the ISFSI access gate and activate the ISFSI security measures.

5.1.2.6 DSC Overpack Monitoring Operations

1. Perform routine security surveillance in accordance with the TMI-2 ISFSI physical protection plan.
2. Perform surveillance of the DSC overpack vent system in accordance with the Technical Specification requirements for a standard HSM/DSC vent system.

5.1.2.7 DSC Retrieval from the Overpack

1. Ready the cask, transport trailer, and support skid for service and tow the trailer to the DSC overpack.
2. Evacuate and backfill the overpack and DSC with fresh air or an inert gas.
3. Cut any welds from the door and remove the HSM door using a porta-crane.

Remove the DSC seismic restraint.

4. Place scaffolding, a containment tent with exhaust system, and welding blankets around appropriate end of the overpack.
5. Using plasma arc-gouging, a mechanical cutting system, or other suitable means, remove the seal weld from the DSC overpack. A fire watch should be present, as appropriate. The exhaust system should be operating, as necessary.
6. The material or waste from the cutting or grinding process should be treated and handled in accordance with the facilities low level waste procedures unless determined otherwise.
7. Remove the tent and exhaust system.
8. Remove the DSC overpack cover plate.
9. Prior to retrieval activities, verify that DSC temperatures are within the control limits of Technical Specifications.
10. Back the trailer to within a few inches of the DSC overpack.
11. Using the skid positioning system, align the cask with the HSM and position the skid until the cask is docked with the HSM access opening.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-13

12. Using optical survey equipment, verify alignment of the cask with respect to the DSC overpack. Install the cask restraints.
13. Install rear cask ram support and align the hydraulic ram with the cask, as necessary.
14. Extend the ram through the cask into the DSC overpack until it is inserted in the DSC grapple ring.
15. Activate the arms on the ram grapple mechanism with the DSC grapple ring.
16. Retract ram and pull the DSC into the cask.
17. Retract the ram grapple arms.
18. Disengage the ram from the cask.
19. Remove the cask restraints.
20. Using the skid positioning system, disengage the cask from the DSC overpack.
21. Install vent and purge port filter/transportation cover assemblies, if required.

Install and leak test (if required for transport) the vent assembly transportation covers.

22. Install the cask internal spacer and top cover plate.
23. Replace the door on the overpack.

5.1.3 Flowsheets The NUHOMS-12T is a passive storage system and requires no operating system other than those systems/operations used in loading and transfer. A description and sequence of operations is provided in Section 5.1.1. A series of pictorial views of operations is also shown in Figure 5.1-1.

5.1.4 Identification of Subjects for Safety Analysis 5.1.4.1 Criticality Control The criticality analyses and controls for the NUHOMS-12T system are described in Section 3.3.4.

5.1.4.2 Chemical Safety There are no hazardous chemicals used in the NUHOMS-12T system that require special precautions. Material control procedures at the TAN facility will ensure that no hazardous chemicals or surface contaminants are introduced.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-14 5.1.4.3 Operation Shutdown Modes NUHOMS-12T is a totally passive system, including DSC venting, and has no operational shutdown modes.

5.1.4.4 Instrumentation Table 5.1-1 shows the typical instruments which might be used to measure conditions or control the operations during the DSC loading, closure, transfer, and storage operations. The instruments are standard industry equipment, which is readily available.

5.1.4.5 Maintenance Techniques The NUHOMS-12T system does not require maintenance during storage except when sampling of the DSCs indicates that filter replacement and DSC purging is required. When required by Technical Specification limits, the DSC would be purged and the HEPA grade filters replaced. HEPA grade filter replacement would be performed using conventional radioactive contamination control practices.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-15 Table 5.1-1 Instrumentation Used for NUHOMS-12T System Operations Instruments Function

1. Gross Gamma/Beta/Neutron Detectors Measure dose rate at DSC top cover plates
2. Pressure and Vacuum Gauges Measure helium, air and vacuum pressures inside DSC. Measure the pressure drop across the HEPA filters.
3. Hydraulic Pressure Gauges and Ram Pressure Relief Valves Measure and limit hydraulic ram force applied to DSC
4. Optical Survey Equipment Align cask and ram with HSM
5. Gas Sampling Equipment Measure hydrogen concentration during vent system surveillance activities
6. Air Particulate Measuring Equipment Measure air samples outside of filters for airborne activity.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-16 Figure 5.1-1 Primary Operations for the NUHOMS-12T System

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-17 Figure 5.1-1 Primary Operations for the NUHOMS-12T System (continued)

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-18 Figure 5.1-1 Primary Operations for the NUHOMS-12T System (continued)

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-19 Figure 5.1-1 Primary Operations for the NUHOMS-12T System (continued)

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.1-20 Figure 5.1-1 Primary Operations for the NUHOMS-12T System (concluded)

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.2-1 5.2 Fuel Handling Systems 5.2.1 TMI-2 Canister Handling and Transfer NUHOMS-12T is a modular storage system which provides for the dry storage of TMI-2 canisters in a horizontal orientation. NUHOMS-12T is a system designed to be installed at the INL INTEC site. It utilizes the existing systems at the TAN for handling TMI-2 canisters and casks. This section describes the TMI-2 canister handling systems that are unique to NUHOMS-12T and used during the DSC loading, closure, and transfer operations. The transfer system is described in this section to illustrate the hardware and procedures required for operation of the NUHOMS-12T system.

5.2.1.1 Function Description Figure 5.1-1 illustrates the DSC loading, closure, and transfer operations.

Transfer System: The transfer system is composed of the cask, lifting device, support skid, skid positioning system, transport trailer, hydraulic ram, and auxiliary equipment as described in Section 1.3.2.

Cask: The cask is used to transfer a loaded DSC to and from the HSM. The cask provides biological shielding during the transfer, loading, and retrieval operations. During transfer of the DSC to the HSM, the top end of the cask is docked within the HSM access opening sleeve. A description of the cask design criteria and capabilities are provided in Chapters 3, 4, and 8.

Cask Transportation Skid: The purpose of the cask transportation skid, shown in Figure 4.7-7, is to transport the cask in a horizontal position to the ISFSI and maintain the cask alignment during the loading and retrieval operations. The skid is mounted on bearing plates and secured to the transport trailer during transport. These bearings permit the skid to be moved in the longitudinal and transverse directions with respect to the trailer. The skid positioning system shown in Figure 4.7-5, allows the DSC to be precisely aligned with the DSC support structure inside the HSM. Section 3.1.2.1 establishes the criteria for design of the cask transportation skid.

Transport Trailer: The function of the transport trailer is two-fold: 1) to transport the loaded cask in the horizontal position to the ISFSI, and 2) to approximately align the cask with the HSM opening. The trailer shown in Figure 4.7-3 is a standard heavy haul trailer capable of handling a 125 ton payload.

Optical Survey Equipment: After the loaded trailer has been backed up to the HSM, the cask is aligned with the HSM. Alignment is achieved using a transit and optical alignment marks on the cask and HSM as shown in Figure 5.2-1. Once the cask is aligned with the HSM, the trailer jacks and cask restraints ensure that alignment is maintained throughout the DSC transfer or retrieval operations.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.2-2 Jack Support System: The tires on the trailer are pneumatic. As the DSC is being transferred into or out of the HSM, the transfer of the load may cause the alignment to be altered or cause the DSC to bind in the cask or HSM. To ensure that the alignment is maintained throughout the DSC transfer or retrieval operations, jacks at four locations on the trailer are used as shown in Figure 4.7-3. The design criteria for the jack support system are established in Section 3.1.2.

Cask Restraints: During the DSC transfer or retrieval operations, the resistance of the DSC could cause the cask to move in its axial direction. This motion could cause the alignment to be altered or the shielding by the HSM and cask to be jeopardized. To ensure that the cask does not move in the axial direction, cask restraints join the HSM front wall embedments to the cask.

Ram and Grappling Apparatus: The ram is a hydraulic cylinder which extends from the back of the cask through the length of the cask as shown in Figure 4.7-

6. The grappling apparatus is mounted on the front of the ram as shown in Figure 4.7-6. The hydraulics for the grappling apparatus are activated, causing the arms to engage the DSC grapple ring. Once the arms are engaged, the ram is extended, pushing the DSC out of the cask and into the HSM. For retrieval of the cask, the process is reversed. The DSC slides along the cask inner liner rails and onto the support rails inside the HSM.

DSC Support Rails: During the transfer operation, the DSC slides out of the cask on hard surfaced rails and onto the support rails inside the HSM as shown in Figure 4.2-3. The support rails in the HSM serve as both the sliding surfaces during the transfer operation as well as supports during DSC storage. The support rail surface that comes into contact with the surface of the DSC, is coated with a lubricant.

5.2.1.2 Safety Features Except for the transfer of the DSC from the cask to the HSM, the loaded DSC is always seated inside the cask cavity. The safety features used in handling the cask at the TAN facility are described in the facility safety procedures.

To ensure that the minimum amount of force is applied to the DSC during the transfer operation, the cask cavity rails and the HSM support rails are coated with a lubricant. A low coefficient of friction minimizes the amount of force applied to the DSC, thus minimizing the possibility of damage to the DSC.

If the motion of the DSC is impeded during the transfer operation and the ram continues to travel, the force exerted by the ram on the DSC will increase. To indicate the occurrence of such an event, the amount of force which the ram may exert is limited by the ram control system and monitored by the operator. The stresses which develop in the DSC due to the maximum loading force are less than the allowable limits of the DSC material and, therefore, the integrity of the canister shell and closure welds is not jeopardized.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.2-3 5.2.2 TMI-2 Canister Storage Descriptions of the operations used for the transfer and retrieval of the DSC from the HSM are presented in Section 5.1.

5.2.2.1 Safety Features The features, systems, and special techniques which provide for safe loading and retrieval operations are described in Section 5.2.1.2.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.2-4 Figure 5.2-1 NUHOMS Cask/HSM Alignment Verification

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.3-1 5.3 Other Operating Systems 5.3.1 Operating System NUHOMS-12T is a passive storage system and requires no operating systems other than those systems used in transferring the DSC to and from the HSM.

5.3.2 Component/Equipment Spares As discussed in Section 8.2, the TMI-2 ISFSI is designed to withstand all postulated design basis events. Therefore, no storage component or equipment spares are required for the standardized NUHOMS-12T system, with the exception of changeout of the HEPA filters.

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TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.4-1 5.4 Operation Support System NUHOMS-12T is a self-contained passive system and requires no effluent processing systems during storage conditions.

5.4.1 Instrumentation and Control System There are no instrumentation and control systems included in the system design. The instrumentation and controls necessary during DSC loading, closure, transfer and periodic testing during storage are described in Section 5.1.4.4.

5.4.2 System and Component Spares There are no instrumentation or control systems used during storage conditions; thus, no other system and component spare parts are required.

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TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.5-1 5.5 Control Room and/or Control Areas There are no control room or control areas for the NUHOMS-12T system.

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TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.6-1 5.6 Analytical Sampling Periodic DSC sampling is performed for the NUHOMS-12T system in accordance with the Technical Specification surveillance and monitoring requirements. The objective of this sampling is to ensure that the hydrogen gas remains at safe levels and the vent system and HEPA filters are functioning properly.

TMI-2 SAR-II-8.4 12/9/19 Chapter 5 Rev. 5 Page 5.6-2 Intentionally Blank

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