ML18285A812

5021048 - Attachment 2: Proposed HI-STORM Umax Certificate of Compliance Amendment 4 ((Non-Proprietary)

ML18285A812
Person / Time
Site:	HI-STORM 100
Issue date:	09/28/2018
From:	Holtec
To:	Office of Nuclear Material Safety and Safeguards
References
5021048
Download: ML18285A812 (13)

Text

NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION (10-2004) 10 CFR 72 CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Page 1

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The U.S. Nuclear Regulatory Commission is issuing this Certificate of Compliance pursuant to Title 10 of the Code of Federal Regulations, Part 72, "Licensing Requirements for Independent Storage of Spent Nuclear Fuel and High-Level Radioactive Waste" (10 CFR Part 72). This certificate is issued in accordance with 10 CFR 72.238, certifying that the storage design and contents described below meet the applicable safety standards set forth in 10 CFR Part 72, Subpart L, and on the basis of the Final Safety Analysis Report (FSAR) of the cask design. This certificate is conditional upon fulfilling the requirements of 10 CFR Part 72, as applicable, and the conditions specified below.

Certificate No.

Effective Date Expiration Date Docket No.

Amendment No.

Amendment Effective Date Package Identification No.

1040 TBD TBD 72-1040 4

USA/72-1040 Issued To: (Name/Address)

Holtec International Holtec Center One Holtec Drive Marlton, NJ 08053 Safety Analysis Report Title Holtec International Final Safety Analysis Report for the HI-STORM UMAX Canister Storage System This certificate is conditioned upon fulfilling the requirements of 10 CFR Part 72, as applicable, the attached Appendix A (Technical Specifications) and Appendix B (Approved Contents and Design Features), and the conditions specified below:

APPROVED SPENT FUEL STORAGE CASK Model No.: HI-STORM UMAX Canister Storage System DESCRIPTION:

The HI-STORM UMAX Canister Storage System consists of the following components: (1) interchangeable canisters, which contain the fuel; (2) underground Vertical Ventilated Modules (VVMs), which contains the canisters during storage; and (3) a transfer cask (HI-TRAC VW), which contains the canister during loading, unloading and transfer operations. The multi-purpose canister (MPC) stores up to 37 pressurized water reactor fuel assemblies or up to 89 boiling water reactor fuel assemblies. The HI-STORM UMAX may also store a dry shielded canister (DSC) which contains up to 24 pressurized water reactor fuel assemblies.

The HI-STORM UMAX Canister Storage System is certified as described in the UMAX Final Safety Analysis Report (FSAR) supplemented by the information on the analyzed canisters and transfer cask, and in the U. S.

Nuclear Regulatory Commissions (NRC) Safety Evaluation Report (SER) accompanying the Certificate of Compliance (CoC).

The MPC is the confinement system for the stored fuel. It is a welded, cylindrical canister with a honeycombed fuel basket, a baseplate, a lid, a closure ring, and the canister shell. All MPC components that may come into contact with spent fuel pool water or the ambient environment are made entirely of stainless steel or passivated aluminum/aluminum alloys. The canister shell, baseplate, lid, vent and drain port cover plates, and closure ring are the main confinement boundary components. All confinement boundary components are made entirely of stainless steel. The honeycombed basket provides criticality control.

Similarly, the welded DSC provides confinement and criticality control for the storage and transfer of irradiated fuel. The principle component subassemblies of the DSC are the shell with integral bottom cover plate and shield plug, top shield plug, top cover plate, and basket assembly. The DSC confinement boundary consists of stainless steel cylindrical shell and the top and bottom cover plate assemblies. The shell length is fuel specific.

The internal basket assembly for the 24PT1 is composed of guide sleeves, support rods, and spacer disks.

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 1 of 13

NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION (3-1999) 10 CFR 72 CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Certificate No.

1040 Amendment No.

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DESCRIPTION (continued)

The DSC basket assembly aids in the insertion of the fuel assemblies, enhances subcriticality during loading operations, and provides structural support.

There are two types of MPCs permitted for storage in HI-STORM UMAX VVM: the MPC-37 and MPC-89. The number suffix indicates the maximum number of fuel assemblies permitted to be loaded in the MPC. The MPC-37 also has an alternative design called the MPC-37 Type 1. Both MPC models have the same external diameter. The DSC type permitted for storage in the HI-STORM UMAX is the DSC-24PT1.

The HI-TRAC VW transfer cask provides shielding and structural protection of the canister during loading, unloading, and movement of the canister from the cask loading area to the VVM. The transfer cask is a multi-walled (carbon steel/lead/carbon steel) cylindrical vessel with a neutron shield jacket or neutron shield cylinder attached to the exterior and a retractable bottom lid used during transfer operations. The HI-TRAC VW is also used for transfer of the DSC-24PT1.

The HI-STORM UMAX VVM utilizes a storage design identified as an air-cooled vault or caisson. The HI-STORM UMAX VVM relies on vertical ventilation instead of conduction through the fill material around the VVM, as it is essentially a below-grade storage cavity. Air inlets and an air outlet allow air to circulate naturally through the cavity to cool the canister inside. The subterranean steel structure is seal welded to prevent ingress of any groundwater in the canister storage cavity from the surrounding subgrade, and it is mounted on a stiff foundation. The surrounding subgrade and a top surface pad provide significant radiation shielding. A loaded canister is stored within the HI-STORM UMAX VVM in a vertical orientation.

HI-STORM UMAX Version MSE is a structurally strengthened embodiment of the VVM engineered for deployment at sites with its Design Basis Earthquake with ZPA in excess of 2.12Gs (resultant horizontal) and up to 1.0G (vertical).

CONDITIONS

1. OPERATING PROCEDURES Written operating procedures shall be prepared for handling, loading, movement, surveillance, and maintenance. The users site-specific written operating procedures shall be consistent with the technical basis described in Chapter 9 and canister specific Chapter 9 supplements of the FSAR.

2. ACCEPTANCE TESTS AND MAINTENANCE PROGRAM Written acceptance tests and a maintenance program shall be prepared consistent with the technical basis described in Chapter 10 and canister specific Chapter 10 supplements of the FSAR.

For the MPCs, at completion of welding the MPC shell to baseplate, an MPC confinement weld helium leak test shall be performed using a helium mass spectrometer. This test shall include the base metals of the MPC shell and baseplate. A helium leakage test shall also be performed on the base metal of the fabricated MPC lid. The confinement boundary welds leakage rate test shall be performed in accordance with ANSI N14.5 to leaktight criterion. If a leakage rate exceeding the acceptance criteria is detected, then the area of leakage shall be determined and the area repaired per ASME Code Section III, Subsection NB, Article NB-4450 requirements. Re-testing shall be performed until the leakage rate acceptance criterion is met.

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 2 of 13

NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION (3-1999) 10 CFR 72 CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Certificate No.

1040 Amendment No.

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3. QUALITY ASSURANCE Activities in the areas of design, purchase, fabrication, assembly, inspection, testing, operation, maintenance, repair, modification of structures, systems and components, and decommissioning that are important-to-safety shall be conducted in accordance with a Commission-approved quality assurance program which satisfies the applicable requirements of 10 CFR Part 72, Subpart G, and which is established, maintained, and executed with regard to the storage system

4. HEAVY LOADS REQUIREMENTS Each lift of an MPC, DSC, or a HI-TRAC VW transfer cask must be made in accordance to the existing heavy loads requirements and procedures of the licensed facility at which the lift is made. A plant-specific review of the heavy load handling procedures (under 10 CFR 50.59 or 10 CFR 72.48, as applicable) is required to show operational compliance with existing plant specific heavy loads requirements. Lifting operations outside of structures governed by 10 CFR Part 50 must be in accordance with Section 5.2 of Appendix A or Appendix C as applicable.

5. APPROVED CONTENTS Contents of the HI-STORM UMAX Canister Storage System must meet the fuel specifications for each canister in the appendices to this certificate as follows:

Canister Approved Contents Appendix MPC-37 Appendix B MPC-89 Appendix B DSC-24PT1 Appendix D

6. DESIGN FEATURES Features or characteristics for the site or system must be in accordance with the applicable appendix to this certificate, identified in item 5.

7. CHANGES TO THE CERTIFICATE OF COMPLIANCE The holder of this certificate who desires to make changes to the certificate, which includes all the appendices (A through D), shall submit an application for amendment of the certificate.

8. PRE-OPERATIONAL TESTING AND TRAINING EXERCISE - MPCs only A dry run training exercise of the loading, closure, handling, unloading, and transfer of the HI-STORM UMAX Canister Storage System shall be conducted by the licensee prior to the first use of the system to load spent fuel assemblies. The training exercise shall not be conducted with spent fuel in the MPC. The dry run may be performed in an alternate step sequence from the actual procedures, but all steps must be performed. The dry run shall include, but is not limited to the following:

a. Moving the MPC and the transfer cask into the spent fuel pool or cask loading pool.

b. Preparation of the HI-STORM UMAX Canister Storage System for fuel loading.

c. Selection and verification of specific fuel assemblies to ensure type conformance.

d. Loading specific assemblies and placing assemblies into the MPC (using a dummy fuel assembly),

including appropriate independent verification.

e. Remote installation of the MPC lid and removal of the MPC and transfer cask from the spent fuel pool or cask loading pool.

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 3 of 13

NRC FORM 651 U.S. NUCLEAR REGULATORY COMMISSION (3-1999) 10 CFR 72 CERTIFICATE OF COMPLIANCE FOR SPENT FUEL STORAGE CASKS Supplemental Sheet Certificate No.

1040 Amendment No.

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f.

MPC welding, NDE inspections, pressure testing, draining, moisture removal (by vacuum drying or forced helium dehydration, as applicable), and helium backfilling. (A mockup may be used for this dry-run exercise.)

g. Transfer of the MPC from the transfer cask to the VVM.

h. HI-STORM UMAX Canister Storage System unloading, including flooding MPC cavity and removing MPC lid welds. (A mockup may be used for this dry-run exercise.)

Any of the above steps can be omitted if the site has already successfully loaded a Holtec MPC System.

PRE-OPERATIONAL TESTING AND TRAINING EXERCISE - DSCs only A dry run training exercise of the handling and transfer of the DSC in the HI-STORM UMAX Canister Storage System shall be conducted by the licensee prior to the first movement of a loaded DSC into a HI-STORM UMAX VVM. The training exercise shall not be conducted with spent fuel in the DSC. The dry run may be performed in an alternate step sequence from the actual procedures, but all steps must be performed. The dry run shall include, but is not limited to the following:

a. Transfer of the DSC from the NUHOMS storage module to the HI-TRAC VW.

b. Transfer of the DSC from the HI-TRAC VW to the VVM

9. AUTHORIZATION The HI-STORM UMAX Canister Storage System, which is authorized by this certificate, is hereby approved for general use by holders of 10 CFR Part 50 licenses for nuclear reactors at reactor sites under the general license issued pursuant to 10 CFR 72.210, subject to the conditions specified by 10 CFR 72.212, this certificate, and the attached Appendices A through D. The HI-STORM UMAX Canister Storage System may be fabricated and used in accordance with any approved amendment to CoC No. 1040 listed in 10 CFR 72.214. Each of the licensed HI-STORM UMAX Canister Storage System components (i.e., the canister, overpack, and transfer cask), if fabricated in accordance with any of the approved CoC Amendments, may be used with one another provided an assessment is performed by the CoC holder that demonstrates design compatibility..

FOR THE U. S. NUCLEAR REGULATORY COMMISSION DRAFT Dated TBD Attachments:

1. Appendix A

2. Appendix B

3. Appendix C

4. Appendix D ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 4 of 13

SFSC Heat Removal System 3.1.2 Certificate of Compliance No. 1040 Amendment No. 4 Appendix A 3.1.2-1 3.1 SFSC INTEGRITY 3.1.2 SFSC Heat Removal System LCO 3.1.2 The SFSC Heat Removal System shall be operable APPLICABILITY: During STORAGE OPERATIONS after closure lid installed.

ACTIONS

---

NOTE--------------------------------------------------

Separate Condition entry is allowed for each SFSC.

CONDITION REQUIRED ACTION COMPLETION TIME A. SFSC Heat Removal System operable, but partially blocked.

A.1 Remove blockage.

N/A B. SFSC Heat Removal System inoperable.

B.1 Restore SFSC Heat Removal System to operable status.

8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> C. Required Action B.1 and associated Completion Time not met.

C.1 Measure SFSC dose rates in accordance with the Radiation Protection Program.

Immediately and once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND C.2.1 Restore SFSC Heat Removal System to operable status.

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> OR C.2.2 Transfer the MPC into a TRANSFER CASK.

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> OR C.2.3 Perform an engineering evaluation to demonstrate that component temperatures are within allowable limits 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 5 of 13

Programs 5.0 Certificate of Compliance No. 1040 Amendment No. 4 Appendix A 5.0-4 5.0 ADMINISTRATIVE CONTROLS AND PROGRAMS (continued) 5.3 Radiation Protection Program (continued) 5.3.6 If the measured surface dose rates exceed the lower of the two limits established in Section 5.3.3 or Section 5.3.4, the licensee shall:

a.

Administratively verify that the correct contents were loaded in the correct fuel storage cell locations.

b.

Perform a written evaluation to verify whether a VVM at the ISFSI containing the as-loaded MPC will cause the dose limits of 10 CFR 72.104 to be exceeded.

c.

Perform a written evaluation within 30 days to determine why the surface dose rate limits were exceeded.

5.3.7 If the evaluation performed pursuant to Section 5.3.6 shows that the dose limits of 10 CFR 72.104 will be exceeded, the MPC shall not be placed into a VVM or the MPC shall be removed from the VVM until appropriate corrective action is taken to ensure the dose limits are not exceeded.

5.3.8 TRANSFER CASK and VVM surface dose rates shall be measured at approximately the following locations:

a.

A minimum of four (4) dose rate measurements shall be taken on the top of the VVM. These measurements shall be taken over the annulus between the MPC and VVM, approximately 90 degrees apart.

b.

A minimum of four (4) dose rate measurements shall be taken adjacent to the outlet vent duct screen of the VVM, approximately 90 degrees apart.

c.

A minimum of four (4) dose rate measurements shall be taken on the side of the TRANSFER CASK approximately at the cask mid-height plane. The measurement locations shall be approximately 90 degrees apart around the circumference of the cask. Dose rates shall be measured between the radial ribs of the water jacket.

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 6 of 13

Certificate of Compliance No. 1040 Amendment No. 2 Appendix B i

TABLE OF CONTENTS 1.0 DEFINITIONS........................................................................................................ 1-1 2.0 APPROVED CONTENTS...................................................................................... 2-1 2.1 Fuel Specifications and loading conditions........................................................ 2-1 2.2 Violations........................................................................................................... 2-1 2.3 Decay Heat Limits........................................................................................... 2-15 Table 2.1-1 Fuel Assembly Limits.......................................................................... 2-2 Table 2.1-2 PWR Fuel Assembly Characteristics.................................................. 2-6 Table 2.1-3 BWR Fuel Assembly Characteristics.................................................. 2-9 Table 2.1-4 Classification of Fuel Assembly for MPC-37 in the HI-STORM UMAX System...................................................................................................... 2-14 Table 2.3-1 Permissible Heat Load for long term storage.................................... 2-16 Table 2.3-2 HI-STORM UMAX MPC-37 Type 1 Permissible Heat Loads............ 2-19 Figure 2.3-1 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 1 for Long-term Storage for Short and Standard Fuel........................................ 2-21 Figure 2.3-2 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 2 for Long-Term Storage for Short and Standard Fuel....................................... 2-22 Figure 2.3-3 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 3 for Long-term Storage for Short Fuel.............................................................. 2-23 Figure 2.3-4 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 3 for Long-term Storage for Standard Fuel........................................................ 2-24 Figure 2.3-5 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 1 for Long-term Storage for Long Fuel............................................................... 2-25 Figure 2.3-6 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 2 for Long-term Storage for Long Fuel............................................................... 2-26 Figure 2.3-7 HI-STORM UMAX MPC-37 Permissible Heat Load Chart 3 for Long-term Storage for Long Fuel............................................................... 2-27 Figure 2.3-8 HI-STORM UMAX MPC-37 Permissible Heat Load for Short and Standard Fuel for Helium Backfill Option3 in Table 3-2 of Appendix A....................................................................................... 2-28 Figure 2.3-9 HI-STORM UMAX MPC-37 Permissible Heat Load for Long Fuel for Helium Backfill Option 3 in Table 3-2 of Appendix A......................... 2-29 Figure 2.3-10 HI-STORM UMAX MPC-89 Permissible Heat Load for Long-Term Storage............................................................................................ 2-30 Figure 2.3-11 HI-STORM UMAX MPC-89 Permissible Heat Load for Helium Backfill Option 2 in Table 3-2 of Appendix A................................................ 2-31 Figure 2.3-12 HI-STORM UMAX MPC-37 Permissible Threshold Heat Load for VDS High Burnup Fuel in Table 3-1 of Appendix A and Helium Backfill Option 3 in Table 3-2 of Appendix A............................................................. 2-32 Figure 2.3-13 HI-STORM UMAX MPC-89 Permissible Threshold Heat Load for VDS High Burnup Fuel in Table 3-1 of Appendix A and Helium Backfill Option ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 7 of 13

Certificate of Compliance No. 1040 Amendment No. 2 Appendix B ii 2 in Table 3-2 of Appendix A............................................................. 2-33 Figure 2.3-14 HI-STORM UMAX MPC-37 Permissible Heat Load for 16x16A Undamaged Fuel with up to Thirty-seven DFCs............................... 2-34 Figure 2.3-15: HI-STORM UMAX MPC-37 Type 1 Heat Permissible Heat Loads...... 2-35 3.0 DESIGN FEATURES............................................................................................. 3-1 3.1 Site.................................................................................................................... 3-1 3.2 Design Features Important for Criticality Control............................................... 3-1 3.3 Codes and Standards........................................................................................ 3-2 3.4 Site Specific Parameters and Analyses........................................................... 3-10 3.5 Combustible Gas Monitoring During MPC Lid Welding and Cutting................ 3-16 3.6 Periodic Corrosion Inspections for Underground Systems.............................. 3-16 Figure 3-1 SUBGRADE AND UNDERGRADE SPACE NOMENCLATURE....3-15 Table 3-1 List of ASME Code Alternatives for Multi-Purpose Canisters (MPCs).... 3-3 Table 3-2 REFERENCE ASME CODE PARAGRAPHS FOR HI-STORM UMAX OVERPACK and HI-TRAC VW TRANSFER CASK, PRIMARY LOAD BEARING PARTS.................................................................................. 3-8 Table 3-3 LOAD COMBINATIONS FOR THE TOP SURFACE PAD, ISFSI PAD, AND SUPPORT FOUNDATION PAD PER ACI-318 (2005)................. 3-12 Table 3-4 Values of Principal Design Parameters for the Underground ISFSI...... 3-13 ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 8 of 13

Approved Contents 2.0 Certificate of Compliance No.1040 Amendment No. 2 Appendix B 2-3 Table 2.1-1 (page 2 of 4)

Fuel Assembly Limits I. MPC MODEL: MPC-37 (continued)

B. Quantity per MPC: 37 FUEL ASSEMBLIES with up to twelve (12) DAMAGED FUEL ASSEMBLIES or FUEL DEBRIS in DAMAGED FUEL CONTAINERS (DFCs). DFCs may be stored in fuel storage locations 1, 3, 4, 8, 9, 15, 23, 29, 30, 34, 35, and 37 (see Figures 2.3-1 through 2.3-7). The remaining fuel storage locations may be filled with PWR UNDAMAGED FUEL ASSEMBLIES meeting the applicable specifications.

OR 37 class 16x16A UNDAMAGED FUEL ASSEMBLIES, with up to thirty-seven (37) of these stored in DAMAGED FUEL CONTAINERS, with up to twelve (12)

DAMAGED FUEL ASSEMBLIES or FUEL DEBRIS stored in DAMAGED FUEL CONTAINERS (DFCs). DAMAGED FUEL ASSEMBLIES or FUEL DEBRIS may be stored in fuel storage locations to 1, 3, 4, 8, 9, 15, 23, 29, 30, 34, 35, and 37 (see Figure 2.3-14). UNDAMAGED FUEL ASSEMBLIES, class 16x16A may be stored in DFCs only under loading pattern shown in Figure 2.3.14 OR For MPC-37 Type 1 only, up to 37 PWR UNDAMAGED FUEL ASSEMBLIES meeting the applicable specifications under loading pattern shown in Figure 2.3.15 C. One (1) Neutron Source Assembly (NSA) is authorized for loading in the MPC-

37.

D. Up to thirty (30) BRPAs are authorized for loading in the MPC-37.

Note 1: Fuel assemblies containing BPRAs, TPDs, WABAs, water displacement guide tube plugs, orifice rod assemblies, or vibration suppressor inserts, with or without ITTRs, may be stored in any fuel storage location. Fuel assemblies containing APSRs, RCCAs, CEAs, CRAs, or NSAs may only be loaded in fuel storage locations 5 through 7, 10 through 14, 17 through 21, 24 through 28, and 31 through 33 (see Figures 2.3-1 through 2.3-7).

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 9 of 13

Approved Contents 2.0 Certificate of Compliance No.1040 Amendment No. 2 Appendix B 2-17 TABLE 2.3-1 PERMISSIBLE HEAT LOAD FOR LONG-TERM STORAGE MPC Type Heat Load Chart Helium Backfill Pressure Option (Notes 1,2)

Permissible Heat Load Per Storage Cell Permissible Aggregate Heat Load, kW (Note 4)

MPC-37 Short Fuel (Note 3) 1 1

Figure 2.3-1 33.88 2

2 Figure 2.3-2 33.70 3

1 Figure 2.3-3 33.53 Standard Fuel (Note 3 and

7) 1 1

Figure 2.3-1 33.88 2

2 Figure 2.3-2 33.70 3

1 Figure 2.3-4 35.30 Long Fuel (Note 3) 1 1

Figure 2.3-5 35.76 2

2 Figure 2.3-6 35.57 3

1 Figure 2.3-7 37.06 Short Fuel (Note 3) 3 Figure 2.3-8 34.28 3

Figure 2.3-12 33.46 Standard Fuel (Note 3) 3 Figure 2.3-8 34.28 3

Figure 2.3-12 33.46 Long Fuel (Note 3) 3 Figure 2.3-9 36.19 3

Figure 2.3-12 33.46 16x16A Fuel with up to 37 DFCs (Note 6) 3 Figure 2.3-14 32.3 (Note 5)

MPC-89 1

Figure 2.3-10 36.32 2

Figure 2.3-11 36.72 2

Figure 2.3-13 34.75 Notes:

1. For helium backfill pressure option pressure ranges see Appendix A, Table 3-2

2. For the details on the use of VDS to dry High Burnup Fuel see Appendix A, Table ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 10 of 13

Approved Contents 2.0 Certificate of Compliance No.1040 Amendment No. 2 Appendix B 2-18 3-1

3. See Table 2.1-4 for fuel length data

4. Aggregate heat load is defined as the sum of heat loads of all stored fuel assemblies. The permissible aggregate heat load is set to 80% of the design basis heat load.

5. This aggregate heat load has been calculated with significant margin to fuel cladding limits, and is therefore not subject to the 80% penalty.

6. As stated in Table 2.1-1 Item I.B, this can include undamaged fuel both in DFCs and not, and damaged fuel in DFCs. These heat load limits apply with one or more undamaged fuel assemblies stored in DFCs.

7. For MPC-37 Type 1, the permissible Aggregate Heat Load is given in Table 2.3-2 ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 11 of 13

Approved Contents 2.0 Certificate of Compliance No.1040 Amendment No. 2 Appendix B 2-19 TABLE 2.3-2 HI-STORM UMAX MPC-37 TYPE 1 PERMISSIBLE HEAT LOADS Fuel Type (Note 1)

Helium Backfill Pressure Option (Note 2)

Heat Load per Storage Cell Permissible Aggregate Heat Load (Note 3), kW Standard Fuel 1

Figure 2.3-15 32.3 Note 1: See Table 2.1-4 for fuel length data Note 2: For helium backfill pressure option pressure ranges see Appendix A, Table 3-2 Note 3: The aggregate heat load is defined as a sum of all stored fuel assemblies.

ATTACHMENT 2 TO HOLTEC LETTER 5021048 Page 12 of 13

Approved Contents 2.0 Certificate of Compliance No.1040 Amendment No. 2 Appendix B 2-35 0.725 0.865 0.725 0.66 1.075 1.24 1.075 0.66 0.725 1.075 0.775 0.865 0.775 1.075 0.725 0.865 1.24 0.865 0.285 0.865 1.24 0.865 0.725 1.075 0.775 0.865 0.775 1.075 0.725 0.66 1.075 1.24 1.075 0.66 0.725 0.865 0.725 Figure 2.3-15: HI-STORM UMAX MPC-37 Type 1 Heat Permissible Heat Loads (All storage cell heat loads are in kW)

Note that this figure shows the per cell heat load limit for storage. The permissible aggregate heat load may be less than the sum of each individual cell heat load. See Table 2.3-2 for corresponding permissible aggregate heat load and the helium backfill option.

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