Text

Enclosure 8 - CoC 1042 Amendment 1, Revision 2, UFSAR Changed Pages
	ML18255A101
Person / Time
Site:	07201042
Issue date:	08/30/2018
From:	; Orano USA, TN Americas LLC
To:	; Office of Nuclear Material Safety and Safeguards
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ML18255A124	List: ML18255A092; ML18255A093; ML18255A094; ML18255A096; ML18255A097; ML18255A098; ML18255A101; ML18255A102;
References
	CAC 001028, CoC No. 1042, E-52372, EPID: L-2018-LLA-0043
	Download: ML18255A101 (72)
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Enclosure 8 to E-52372

CoC 1042 Amendment 1, Revision 2 UFSAR Changed Pages (Public Version)

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-2 Introduction 1.1The type of fuel to be stored in the NUHOMS EOS System is light water reactor (LWR) fuel of the PWR and BWR type.

The EOS-37PTH DSC is designed to accommodate up to 37 intact PWR FAs with uranium dioxide (UO

2) fuel, zirconium alloy cladding, and with or without control components (CCs). The EOS-37PTH DSC is also designed to accommodate up to eigh t damaged FAs or up to four failed fuel canisters (FFCs) with the balance intact FAs. The EOS-89BTH DSC is designed to accommodate up to 89 intact BWR FAs with uranium dioxide (UO

2) fuel, zirconium alloy cladding, and with or without fuel channels. The physi cal and radiological characteristics of these payloads are provided in Chapter 2.

The NUHOMS EOS System consists of the following components as shown in Figure 1-1 through Figure 1-7: Two dual-purpose (storage and transportation) DSCs that provide confinement in an inert environment, structural support and criticality control for the FAs; the EOS-37PTH DSC and the EOS-89BTH DSC. The DSC shells are welded stainless or duplex steel pressure vessels that includes thick shield plugs at either end to maintain occupational exposures as low as reasonably achievable (ALARA). Six EOS-37PTH DSC basket designs.

Basket Types 1 through 3 correlate with the respective HLZCs 1 through 3 (Figures 1A through 1C of the Technical Specifications [1-7]). Basket Type 4 in corporates a plate configuration that offsets the aluminum plates to allow fo r damaged/failed fuel storage in the EOS-37PTH DSC. The Type 4 basket has two options

. The Type 4H basket is fabricated from a coated steel plate fo r higher emissivity and higher conductivity poison plate, while the Type 4L basket has a low emissivity c oated steel plate and a low conductivity poison plate. These requirements are further detailed in the material and design limits discussed in Section 4.2 and Section 10.1. The Type 5 basket is similar to the Type 1/2/3 basket in configuration, but also incorporates the low emissivity coated steel plates and low conductivity poison plate. The maximum heat loads and the allowable HLZCs for Basket Types 4 and 5 are listed in Table 1-2. Each of these basket types also allows for two levels of boron loading in the poison plates (A and B). Each basket type is designated as follows:

EOS-37PTH Basket Types Neutron Poison Loading Option TYPE 1 (HLZC 1 max. 50 kW) TYPE 2 (HLZC 2 max. 41.8 kW) TYPE 3 (HLZC 3 (max. 36.35 kW) TYPE 4 (Damaged/Failed Fuel) TYPE 5 (Low K, Low ) A (Low B-10)

A1 A2 A3 A4H/A4L A5 B (High B-10)

B1 B2 B3 B4H/B4L B5 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-3 Three EOS-89BTH DSC basket designs. Ba sket Types 1 through 3 correlate with the respective HLZC 1 through 3 (Figure 2 of the Technical Specifications [1-7]).

Each of these basket types also allows for three levels of boron loading in the poison plates (Low, Moderate, and High).

EOS 89BTH Basket Types Neutron Poison Loading Option Type 1 (HLZC 1 max. 43.6 kW)

Type 2 (HLZC 2 max. 41.6 kW)

Type 3 (HLZC 3 max. 34.44 kW) M1-A (Low B-10) A1 A2 A3 M1-B (Moderate B-10) B1 B2 B3 M2-A (High B-10) C1 C2 C3 The criticality evaluations in Chapter 7 refer to the basket types based on the boron content in the poison plates. In Ch apter 7, the references to the basket types differ from the above table. The co rrelations between the basket types used in Chapter 7 and basket types identified in the above table are clarified below:

- EOS-37PTH basket types A1, A2, A3 , A4H, A4L, and/or A5 are identified as EOS-37PTH basket type A in Chapter 7

- EOS-37PTH basket types B1, B2, B3 , B4H, B4L, and/or B5 are identified as EOS-37PTH basket t ype B in Chapter 7

- EOS-89BTH basket types A1, A2, and/or A3 are identified as EOS-89BTH basket type M1-A in Chapter 7

- EOS-89BTH basket types B1, B2, and/or B3 are identified as EOS-89BTH basket type M1-B in Chapter 7

- EOS-89BTH basket types C1, C2, and/or C3 are identified as EOS-89BTH basket type M2-A in Chapter 7 The thermal evaluation in Chapter 4 refers directly to the HLZC instead of using the basket types.

Provisions have been made for storage of up to eight damaged fuel assemblies in lieu of an equal number of intact assemblies placed in cells located in the EOS-37PTH basket as shown in Figures 1F and 1H of the Technical Specifications.

Damaged fuel assemblies are define d in Section 1.1 of the Technical Specifications [1-7].

The EOS-37PTH DSC is also designed to accommodate up to a maximum of four FFCs, placed in cells located at the oute r edge of the DSC as shown in Figures 1F and 1H of the Technical Specifications.

Failed fuel is defined in Section 1.1 of the Technical Specifications [1-7].

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-4 The damaged/failed fuel basket is identical to the intact fuel basket with the exception that the aluminum in the composite basket plates has been offset vertically in order to prevent debris from the damaged fuel from migrating between basket plates to adj acent compartments. The offset is accomplished by lengthening the aluminum plates in the bottom section by [ ] and subsequently shortening the top-most aluminum plates by that same [ ] The middle sections of aluminum plates remain the same height as the intact basket. The damaged/failed basket confi guration is shown in Figure 1-2a.

Damaged fuel assemblies must contain end f ittings or nozzles or tie plates at the top and bottom. A n HSM design, designated as either the EOS-HSM or the EOS-HSMS, is equipped with special design features for enhanced shielding and heat rejection capabilities. The HSM base has two alternatives, a single piece or a split base. The HSM with the split base is designated as the EOS-HSMS. Finally, the EOS-HSM and EOS-HSMS can be fabricated with three lengths to accommodate the range of DSC lengths, pr ovided in the table below.

NUHOMS Module DSC Length without Grapple Ring (in.)

Total EOS-HSM Length (in.)

Minimum (in.) Maximum (in.) EOS-Short 165.5 179.5 228 EOS-Medium 185.5 199.5 248 EOS-Long 205.5 219.5 268 EOS-HSM and EOS-HSMS modules are arranged in arrays to minimize space and maximize self-shielding. The DSCs ar e longitudinally restrained to prevent movement during seismic events. Arrays are fully expandable to permit modular expansion in support of operating power plants. The EOS-HSM and EOS-HSMS provides the bulk of the radiation shielding for the DSCs. The EOS-HSM/EOS-HSMS can be arranged in either a single-row or a back-to-back arrangement. Thick concrete supplemental shield walls are used at either end of an EOS-HSM and EOS-HS MS array and along the back wall of single-row arrays to minimize radiation dos e rates both onsite and offsite. Two or more empty modules can be substituted fo r the end walls until the array is fully built. A horizontal storage module (HSM), designat ed as the HSM-MX, is a two-tiered, staggered reinforced monolithic structure, consisting of massive reinforced concrete compartments to accommodate EOS-DSCs. This system is further detailed in Appendix A, where relevant c hapters are preceded with an A, i.e., A.1. Where the term "HSM" is used without distinction, this term applies to both the EOS-HSM and HSM-MX.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-7

1.2.1 NUHOMS

EOS System Characteristics EOS-37PTH DSC 1.2.1.1The key design parameters of the EOS-37PTH DSC are listed in Table 1-1. The primary confinement boundary for the EOS-37PTH DSC consists of the cylindrical shell, the top and bottom inner cover plates, the drain port cover plate, vent plug, and the associated welds. The outer top cove r plate and the test port plug provide the redundant sealing required by 10 CFR 72.236(e). The top and bottom shield plugs provide shielding for the EOS-37PTH DSC so that occupational doses at the ends are minimized during drying, sealing, handling, and transfer operations.

The cylindrical shell and inner bottom cover plate confinement boundary welds are fully compliant with Subsection NB of the ASME Code and are made during fabrication. The confinement boundary weld between the shell and the inner top cover (including drain port cover plate and vent plug welds), and the structural attachment weld between the shell and the outer top cover plate (including the test port weld) are in accordance with Alternatives to the ASME code as described in Section 4.4.4 of the Technical Specifications [1-7]. Both drain port cover plate and vent plug welds are made after drying operations are completed. There are no credible accidents that could breach the confinement boundary of the EOS-37PTH DSC, as documented in Chapters 3 and 12. The EOS-37PTH DSC basket structure, shown schematically in Figure 1-2, consists of interlocking slotted plates to form an egg-crate type structure. The egg-crate structure forms a grid of 37 fuel compartments that house the PWR SFAs. The egg-crate grid structure is composed of one or more of the following: a steel plate, an aluminum plate and a neutron absorber plate. The steel pl ates are fabricated from high-strength low-alloy (HSLA) steels such as ASTM A829 Gr 4130 (AISI 4130) steel, hot rolled, heat-treated and tempered to provide structural support for the FAs. The poison plates are made of borated metal matrix composites (MMCs) and provide the necessary criticality control. The aluminum plates, together with the poison plates, provide a heat conduction path from the FAs to the DSC rails and shell. The aluminum plates of the EOS-37PTH DSC may be offset vertically from the steel and poison plates. This configuration is termed the EOS-37PTH damaged/failed fuel basket. This configuration is used in c onjunction with top and bottom end caps to allow for the storage of damaged FAs , as shown in Drawing EOS01-1010-SAR.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-8 The EOS-37PTH damaged/failed fu el basket configuration is also used in conjunction with failed fuel canisters to allow for failed fuel to be stored in the EOS-37PTH DSC.

Each FFC is constructed of sheet metal and is provided with a welded bottom closure and a removable top closure that allows lifti ng of the FFC. The FFC is provided with screens at the bottom and top to contain the failed fuel and al low fill/drainage of water from the FFC during loading operations. The FFC is protected by the fuel compartment tubes and its only function is to confine the faile d fuel. The FFC geometry and the materials used for its fabrication are shown on Drawing EOS01-1010-SAR.

Basket "transition rails" provide the transiti on between the rectangular basket structure and the cylindrical DSC shell. The transition rails are made of extruded aluminum open or solid sections, which are reinforced with internal steel, as necessary. These transition rails provide the transition to a cylindrical exterior surface to match the

inside surface of the DSC shell. The transi tion rails support the fu el basket egg-crate structure and transfer mechanical loads to the DSC shell. They also provide the thermal conduction path from the basket assembly to the DSC shell wall, making the basket assembly efficient in rejecting heat from its payload. The nominal dimension of each fuel compartment opening is sized to accommodate the limiting assembly with sufficient clearance around the FA. The EOS-37PTH DSC is designed for a maximum heat load of 50.0 kW. The internal basket assembly contains a storage position for each FA. The criticality analysis credits the fixed borated neutron absorbing material placed between the FAs. The analysis also takes credit for soluble bor on during loading operati ons. Sub-criticality during wet loading/unloading, drying, sealing, transfer, a nd storage operations is maintained through the geometric separation of the FAs by the basket assembly, the boron loading of the pool wa ter, and the neutron absorbing capability of the EOS-37PTH DSC materials, as applicable. Based on coating of basket steel plates, poison material and boron loading, and the HLZC, twelve basket configurations are provided, as shown on drawing EOS01-1010-SAR for the intact and damaged/failed fuel basket. Poison material and boron loadi ng requirements as well as basket plate coating requirements are discussed in Chapter 10. In general, the dimensions of the EOS-37PTH DSC components described in the text and provided in figures and tables of this UFSAR are nominal dimensions for general system description purposes. Actual design dimensions are contained in the drawings in Section 1.3.1 of this U FSAR. See Sections 1.4.1 and 2.2.1 for a discussion of the contents authorized to be stored in this DSC.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-13 Cask Support Skid: A typical cask support skid for the NUHOMS EOS System is shown in Figure 1-10, and is similar to the cask suppor t skids described in the NUHOMS HD System UFSAR. Key design features are: The skid is mounted on a surface with sliding support bearings and positioners to provide alignment of the cask with the EOS-HSM. A mechanism is provided to prevent movement during trailer towing. A hydraulic or mechanical ram is mounted on the skid to insert or retrieve the DSC from the EOS-HSM. The cask support skid is mounted on a low profile heavy-haul or self-powered industrial trailer. The plant's fuel or reactor building crane or other suitable lifting device is used to lower the cask onto the support skid, which is secured to the transfer trailer. Specific details of this operation and the plant-specific building arrangement are covered by the provisions of the 10 CFR 50 operating license for the plant. Ram: A hydraulic or mechanical ram system consists of a hydraulic cylinder or mechanical frame with a capacity and a reach sufficient for DSC insertion into and retrieval from the EOS-HSM. The design of the ram support system provides a direct load path for the ram reaction forces during DSC insertion and retrieval. The system uses a rear ram support for alignment of the ram to the DSC. The design provides positive alignment of the major components dur ing DSC insertion and retrieval.

1.2.3 Operational

Features for Loading EOS-HSMs This section provides a discussion of th e sequence of operations involving the NUHOMS EOS System components.

Spent Fuel Assembly Loading Operations 1.2.3.1The primary operations (in sequenc e of occurrence) for the NUHOMS EOS System with the EOS-TC125 or EOS-TC135 are:

1. Prepare TC

2. Prepare DSC

3. Place DSC in TC 3a. If damaged fuel is being loaded, insert bottom end caps to specified locations. If failed fuel is being loaded, insert the failed fuel canisters to specified locations.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-14

4. Fill TC/DSC Annulus with clean water and seal

5. Fill DSC cavity with water (may be accomplished in step 6)

6. Lift TC and place in fuel pool

7. Load spent fuel , including top end caps/top lid if damaged or failed fuel is being loaded in the sp ecified locations.

8. Place top shield plug

9. Lift TC from pool (DSC water may be drained and replaced with helium during draindown)

10. Seal inner top cover

11. Vacuum Dry and Backfill

12. Pressure test

13. Leak test

14. Seal outer top cover plate

15. Drain TC/DSC annulus and place TC top cover plate

16. Place loaded TC on transfer skid/trailer

17. Move loaded TC to EOS-HSM

18. Prepare and align TC/EOS-HSM

19. Insert DSC into EOS-HSM

20. Close EOS-HSM For operations (in sequence of occurrence) for the NUHOMS EOS System with the EOS-TC108 the following additional steps may be used to meet crane limits. Concurrent with Step 1 the TC108 neutron shield tank may be removed from the cask and positioned for installation onto the cask once it is loaded and removed from the fuel pool. Between Step 9 and Step 10, the neutron shie ld tank is reinstalled and filled with water. These operations are described in the follo wing paragraphs. The descriptions are intended to be generic and are described in greater detail in Chapter 9. Plant specific requirements may affect these operations a nd are to be addressed by the licensee.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-15 Prepare TC:

Transfer cask preparation includes exterior washdown and interior decontamination. These operations are performed on the decontamination pad/pit outside the fuel pool area. The operations are similar to thos e for a shipping cask, which are performed by plant personnel using existi ng procedures. For the TC108, this includes removing the neutron shield tank if required to meet crane capacity limits or cask loading space considerations. Prepare DSC: The internals and externals of the DSC are inspected and cleaned if necessary. This ensures that the DSC will meet plant cleanliness requirements for placement in the spent fuel pool. If the neutron shield tank is removed from the TC108, position the tank such that it can be installed onto the cask once the cask is loaded and removed from the fuel pool.

Insert bottom end caps and/or failed fu el canisters to specified locations Bottom end caps are installed in specified locations if damaged fuel is being loaded.

Failed fuel canisters are instal led in specified locations if failed fuel is being loaded.

Place DSC in TC: The empty DSC is inserted into the TC. Fill TC/DSC annulus with clean water and seal: The TC/DSC annulus is filled with uncontaminated water and is then sealed prior to placement in the pool. This prevents contamination of the DSC outer surface and the transfer cask inner surf ace by the pool water. Fill DSC cavity with water: The DSC cavity is filled with pool water to pr event an in-rush of wa ter as the transfer cask is lowered into the pool. Lift TC and place in fuel pool: The TC, with the water-filled DSC inside, is then lowered into the fuel pool. The TC125 and TC135 liquid neutron shield may be left unfilled to meet hook weight limitations.

Load spent fuel: Spent fuel assemblies are placed into the DSC , including top end caps or top lids for damaged/failed fuel at specified locations. This operation is identical to that presently used at plants for shipping cask loading.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 1-22 NUHOMS EOS System Contents 1.4 1.4.1 EOS-37PTH DSC Contents The EOS-37PTH DSC is designed to store up to 37 intact PWR FAs with or without CCs. Up to eight damaged FAs, or up to four compartments with failed fuel may be stored in lieu of intact fuel as show n in Figures 1F and 1H of the Technical Specifications [1-7].

The EOS-37PTH DSC is qualified for storage of Babcock and Wilcox (B&W) 15 x 15 class, Combustion Engineering (CE) 14 x 14 class, CE 15 x 15 class, CE 16 x 16 class, Westinghouse (WE) 14 x 14 class, WE 15 x 15 class, and WE 17x17 class PWR FA designs, as described in Chapter 2. The EOS-37PTH DSC payload may include CCs that are contained within the FA, such as described in Chapter 2. Reconstituted assemblies containing up to five replacement irradiated stainless steel rods per assembly or an unlimited number of low enriched or natural uranium fuel rods or unirradiated non-fuel rods are acceptable for storage in an EOS-37PTH DSC as intact FAs. The EOS-37PTH DSC is also authorized to store FAs containing blended low enriched uranium (BLEU) fuel material. Limitations for storing BLEU fuel are provided in Chapter 2. The contents of the DSC are stored in an inert atmosphere of helium.

The maximum allowable planar average initial enrichment of the fuel to be stored is 5.00 wt. % U-235, and the maximum assembly average burnup is 62,000 MWd/MTU. The FAs (with or without CCs) must be cooled to meet the decay heat limits specified in Figure 1A through 1I of the Technical Specifications [1-7] prior to storage. The criticality control features of the EOS-37PTH DSC are designed to maintain the neutron multiplication factor k-effective (including uncertainties and calculational bias) at less than 0.95 under normal, off-normal, and accident conditions.

The gamma and neutron source terms in the SFAs are described and tabulated in Chapter 6. Chapter 7 covers the criticality safety of the EOS-37PTH DSC and its parameters. These parameters include rod pitch, rod outside diameter, material densities, moderator ratios, soluble boron content and geometric configurations. The maximum pressure buildup in the EOS-37PTH DSC cavity is addressed in Chapter 4.

1.4.2 EOS-89BTH DSC Contents The EOS-89BTH DSC is designed to store up to 89 intact BWR FAs with or without channels.

Proprietary and Security Related Information for Drawing EOS01-1010-SAR, Rev. 2C Withheld Pursuant to 10 CFR 2.390 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-5 Spent Fuel to Be Stored 2.2 The NUHOMS EOS System is designed to accommodate pressurized water reactor (PWR) (14x14, 15x15, 16x16 and 17x17 array designs) and boiling water reactor (BWR) (7x7, 8x8, 9x9 and 10x10 array designs) fuel types and reload assemblies that are available for storage. As described in Chapter 1, there are two DSC designs for the NUHOMS EOS System: the EOS-37PTH DS C for PWR fuel and EOS-89BTH DSC for BWR fuel. The EOS-37PTH DSC is designed to accommodate up to 37 intact PWR FAs with uranium dioxide (UO

2) fuel, zirconium-alloy cladding, and with or without control components.

The EOS-37PTH DSC is also designed to accommodate up to eight damaged FAs or up to f our failed fuel canisters (FFCs), with the balance being intact FAs. The EOS-89BTH DSC is designed to accommodate up to 89 intact BWR FAs with UO 2 fuel, zirconium-alloy cladding, and with or without fuel channels.

Specifications for the fuel to be stored in the NUHOMS EOS System are provided in Technical Specifications (TS) Sections 2.1 and 2.2.

The cavity length of the DSC is determined for a specific site to match the FA length used at that site, including control components (CCs), as applicable. Both DSCs store intact, including reconstituted and blended low enriched uranium (BLEU), FAs as specified in Table 2-2, Table 2-3 and Table 2-4. Any FA th at has fuel characteristics within the range of Table 2-2, Table 2-3 and Table 2-4 and meets the other limits specified for initial enrichment, burnup and heat loads is acceptable for storage in the NUHOMS EOS System.

Damaged and failed fuel from the FA classes detailed in Table 2-2 and PWR fuels in Table 2-4 are also acceptable for storage in the EOS-37PTH DSC in the appropriate compartments, as shown in Figures 1F and 1H of the Technical Specifications [2-18].

The potential for fuel reconfiguration fo r intact, damaged, and failed fuel under normal, off-normal, and accident conditions is summarized in Table 2-4a. All fuel categorized as failed shall be placed in a failed fuel canister (FFC). Failed fuel may include FAs, fuel rods, segments of fuel rods, fuel pellets, and debris. FFCs are not required for damaged FAs, because damaged FAs maintain their geometry under normal and off-normal conditions. The failed fuel content of each FFC is limit ed to the maximum metric tons of uranium (MTU) of an intact fuel assembly for ea ch class. These limits are summarized in Table 2-4b.

Failed CCs may also be stored inside an FFC. The maximum Co-60 content for failed CCs is the same as intact CCs and is defined in Table 3 of the Technical Specifications [2-18].

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-6 The maximum allowable assembly average burnup is limited to 62 GWd/MTU and the minimum cooling time is two years. Dummy FAs and reconstituted FAs are also included in the EOS-37PTH DSC and EOS-89BTH DSC payloads.

Low enriched or natural uranium fuel rods or unirradiated non-fuel rods are acceptable for storage in an EOS-37PTH DSC and EOS-89BTH DSC as intact FAs. Fuel assemblies that contain fi xed integral non-fuel rods are also considered as intact FAs. These FAs are different than reconstituted assemblies because fuel rods are not "replaced" by non-fuel rods, rather the non-fuel rods are part of the initial fuel design.

The non-fuel rods displace the same amount of moderator, with zirconium-alloy (or aluminum) cladding and typically contain burnable absorber (or other non-fuel) material. The radiation and thermal source terms for the non-fuel rods are significantly lower than those of the fuel r ods since there is no significant radioactive decay source. The internal pressure of the non-fuel rods after irra diation is lower than those of the fuel rods since there is no fission gas generation. The reactivity of the fuel rods (from a criticality standpoint) is significantly higher than that of non-fuel rods. In summary, the mechanical, thermal, shielding, and critic ality evaluations for these rods are bounded by those of the regul ar fuel rods. Therefore, no further evaluations are required for the qualification of these FAs. Fuel assemblies are evaluated with five irradiated stainless steel rods per assembly, and 40 rods per DSC.

The cooling time is the same as unreconstituted FAs.

The reconstituted rods can be at any location in the FAs.

There is no limit on the number of reconstituted FAs per DSC; the FAs containing irradiat ed stainless steel reconstituted rods are modeled in the inner compartments as shown in Figure 6-1 for EOS-37PTH and Figure 6-2 for EOS-89BTH of Chapter 6.

For BLEU fuel the Co-60 activity in the UO 2 matrix after irradi ation is based on the values shown in Section 6.2.5. The EOS-37PTH DSC may contain less than 37 FAs and the EOS-89BTH DSC may contain less than 89 FAs. In both DSCs, the basket slots not loaded with FAs may have empty slots or be loaded with dummy FAs. The dummy FAs approximate the weight and center of gravity of an FA.

The NUHOMS EOS-37PTH DSC can also acco mmodate up to eight damaged FAs placed in the DSC as shown in Figures 1F and 1H of the Technical Specifications [2-18]. Damaged PWR FAs are defined in Sect ion 1.1 of the Techni cal Specifications [2-18]. The NUHOMS EOS-37PTH DSCs can also accommodate up to a maximum of four FFCs, placed in cells located on the outer edge of the DSC as shown in Figures 1F and 1H of the Technical Specifications [2-18]. Failed fuel is defined in Section 1.1 of the Technical Specifications [2-18].

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-7 Following loading, each DSC is evacuated and then backfilled with an inert gas, helium, to preclude detrimental chemical reaction between the fuel and the DSC

interior atmosphere during st orage. Multilayer, double seal welds at each end of the DSC and multi-layer circumferential a nd longitudinal DSC shell welds ensure retention of the helium atmosphe re for the full storage period.

2.2.1 EOS-37PTH DSC The EOS-37PTH DSC stores up to 37 PWR FAs with up to eight damaged FAs or four FFCs with characteristics as described in Table 2-2 and the PWR FAs listed in Table 2-4. One or more PWR fuel designs are grouped under a "PWR class". EOS-37PTH DSC payloads may also contain CCs, such as identified below, with thermal and radiological characteristics as listed in Table 3 and Figure 1 A through 1I of the Technical Specifications [2-18]:

Burnable Poison Rod Assemblies

- Burnable poison rod assemblies (BPRAs), - Burnable absorber assemblies (BAAs), - Wet annular burnable absorbers (WABAs), - Vibration suppression inserts (VSIs), Thimble Plug Assemblies

- Thimble plug assemblies (TPAs), - Control spiders, - Orifice rod assemblies (ORAs), Control Element Assemblies

- Control rod assemblies (CRAs), - Rod cluster control assemblies (RCCAs), - Control element assemblies (CEAs), - Axial power shaping rod assemblies (APSRAs), - Peripheral power suppression assemblies (PPSAs), - Flux suppression inserts (FSIs), Neutron Sources

- Neutron sources,

- Neutron source assemblies (NSAs).

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-9 Damaged fuel containing control compone nts may be stored in the designated damaged fuel compartments. Similarly, failed control component debris may be stored in the FFCs.

Control components not explicitl y listed herein, but that me et the definition provided above and have similar functional characterist ics as those listed above, are also authorized within the DSC.

Figure s 1 A through 1I of the Technical Specifications [2-18] defines the maximum decay heat

, failed/damaged fuel locations, and other parameters for PWR fuel assemblies, with or without CCs, authorized for storage. These tables are used to ensure that the decay heat load of the FA to be stored is less than that as specified in each table, and that the corresponding radiation source term is consistent with the shielding analysis presented in Chapter 6. The maximum weight of a FA plus CC, if

applicable, is 1,900 lbs.

The heat loads listed in in Figures 1A th rough 1I of the Technical Specifications [2-18] are the maximum allowable heat loads for each FA and the maximum allowable heat load per DSC. These heat loads can be reduced to ensure adequate heat removal capability is maintained to accommodate si te-specific conditions. Some examples of the site-specific conditions are a higher am bient temperature, different blocked vent duration, a requirement to use a different ne utron absorber plate or a requirement for a specific coating on the basket steel plates. Each of th ese changes could result in a change to the inputs of the thermal evaluation utilized in the UFSAR. To ensure that adequate heat removal is maintained with these modified inputs, the bounding evaluations for storage and transfer operations should be re-evalu ated. The maximum fuel cladding temperature based on the m odified inputs shall be lower than the maximum fuel cladding temperatures listed in the Chapter 4 and Chapter A.4 for the same bounding evaluations.

As limited by their definition, damaged FAs ma intain their geometri c configuration for normal and off-normal conditions and are confined to their respective compartments by means of top and bottom end caps. Da maged FAs do not contain missing major sub-components like top and botto m nozzles that impact their ability to maintain their geometric configuration for normal and off-normal conditions during loading. From the standpoint of NUREG-1536 R evision 1, the damaged FAs for the EOS System are more similar to the undamaged FAs, where their geometry is still in the form of intact bundles. For completeness, failed fuel for the EOS System is more similar to the damaged FAs per NUREG-1536 Revision 1 and will require FFCs.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-10 The fuel compartment and the top and bottom end cap together form the "acceptable alternative," per NUREG-1536 Revision 1 for confinement of damaged fuel. If fuel particles are released from the damaged assembly, the top and bottom end caps provide for the confinement of gross fuel particle s to a known volume. Similarly, the FFC provides confinement of the FFC c ontents to a known volume, and has lifting features to allow the ability to unload the FFC. Additionally, consistent with ISG-2, Revision 2, ready retrieval of the damaged and failed fuel is based on the ability to remove a canister from the HSM.

The structural analysis for damaged fu el cladding described in Chapter 3 demonstrates that the cladding does not undergo additional degradation under normal and off-normal conditions of storage. The structural analyses performed for FFCs are provided in Section 3.9.2.1A. The critic ality analysis described in Chapter 7 is based on damaged and failed fuel in the most limiting credible geometry and material reconfigurations under normal, off-normal, and accident conditions. The maximum enrichment values for damaged and/or failed fuel are reduced to account for fuel reconfiguration. The thermal analysis described in Chapter 4 limits the maximum allowable heat load per DSC storing damaged or failed fuel to be less than that for when storing only intact FAs. The shie lding analysis described in Chapter 6 demonstrates that damaged or failed fuel reconfiguration has a negligible effect on dose rates compared to intact fuel.

Calculations were performed to determine the FA type that was most limiting for each of the analyses including sh ielding, criticality, thermal and confinement. These evaluations are performed in Chap ter 6, 7, 4 and 5, respectively.

2.2.2 EOS-89BTH DSC The EOS-89BTH DSC design accommodate s up to 89 intact BWR FAs with characteristics as described in Table 2-3, and the BWR FAs listed in Table 2-4. One or more BWR FA designs are grouped under a "BWR Fuel ID". The EOS-89BTH accommodates:

Fuel assemblies with and without channels,

Fuel assemblies with and without channel fasteners.

Figure 2 of the Technical Specifications [2-18] define the maximum decay heat and other parameters for BWR fuel assemblies authorized for storage. These tables are used to ensure that the decay heat load of the fuel assembly to be stored is less than that as specified in each table, and that the corresponding radiation source term is consistent with the shielding analysis presented in Chapter 6. The maximum weight of an FA plus channel, if applicable, is 705 lbs.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-19

2.4.2 Structural

EOS-DSC Design Criteria 2.4.2.1 The principal design criteria for the DSCs are presented in Table 2-5 and Table 2-6.

The EOS-37PTH DSC is designed to store intact PWR FAs with or without CCs , damaged fuel and failed fuel canisters. The EOS-89BTH DSC is designed to store intact BWR FAs with or without fuel channels. The maximum total heat generation rate of the stored fuel is limited to 50 kW per DSC for the EOS-37PTH DSC and 43.6 kW per DSC for the EOS-89BTH DSC, in order to keep the maximum fuel cladding temperature below the limit necessary to ensure cladding integrity. The maximum heat load for any single assembly is 2

.4 kW for the EOS-37PTH DSC and 0.6 kW for the EOS-89BTH DSC. The fuel cladding integrity is assured by limiting fuel cladding temperature and maintaining a nonoxidizing environment in the DSC cavity as described in Chapter 4.

EOS-HSM Design Criteria 2.4.2.2 The principal design criteria for the EOS-HSM/EOS-HSMS, both the module and DSC support structure, are presented in Table 2-7. The EOS reinforced concrete EOS-HSM is designed to meet the requirements of ACI 349-06 [2-3]. The ultimate strength method of analysis is utilized with the appropriate strength reduction factors as described in Appendix 3.9.4. The load combinations specified in Section 6.17.3.1 of ANSI 57.9-1984 are used for combining normal operating, off-normal, and accident loads for the EOS-HSM. All seven load combinations specified are considered and the governing combinations are selected for detailed design and analysis. The resulting EOS-HSM load combinations and the appropriate load factors are presented in A ppendix 3.9.4. The effects of duty cycle on the EOS-HSM are considered and found to have negligible effect on the design.

EOS-TC Design Criteria 2.4.2.3The EOS-TCs are designed in accordance with the applicable portions of the ASME Code,Section III, Division 1, Subsection NF for Class 1 vessels, except for the neutron shield tank, which is designed to ASME Code,Section III, Division 1, Subsection ND, since it will see pressure greater than 15 psig. The load combinations considered for the TC normal, off-normal, and postulated accident loadings are shown in Table 2-8. Service Levels A and B allowables are used for all normal operating and off-normal loadings. Service Levels C and D allowables are used for load combinations that include postulated accident loadings. The maximum shear stress theory is used to calculate principal stresses in the cask structural shell. Allowable stress limits for the lifting trunnions conservatively meet the requirements of ANSI N14.6- 1993 [2-14] for critical loads.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-26 Table 2-1 NUHOMS EOS System Major Components and Safety Classification Component 10 CFR 72 Classification (1) Dry Shielded Canister (EOS-37PTH DSC and EOS-89BTH DSC) Basket Steel Plate ITS Poison Plate ITS Basket Aluminum Plate ITS Transition Rails ITS Transition Rail Tie Rod and Nuts ITS Transition Rail Angle Plates ITS Transition Rail Screw, Washer and Nut ITS Shell ITS Outer Top Cover Plate ITS Top Shield Plug ITS Inner Top Cover Plate ITS Inner Bottom Cover Plate ITS Bottom Shield Plug ITS Outer Bottom Cover Plate ITS DSC Lifting Lug NITS Siphon Assembly NITS Drain Port Cover and Vent Plug ITS Test Port Plug ITS Grapple Ring and Grapple Support ITS Basket Key ITS Weld Filler Metal ITS Top and Bottom End Caps ITS Failed Fuel Canisters ITS Horizontal Storage Module (EOS-HSM/EOS-HSMS) Reinforced Concrete ITS DSC Support Structure ITS Thermal Instrumentation (if used) NITS ISFSI Basemat and Approach Slabs NITS Transfer Equipment EOS-TC (TC135/TC125/TC108)

ITS Cask Lifting Yoke See Note 2 Transfer Trailer/Skid NITS Ram Assembly NITS Dry Film Lubricant NITS Auxiliary Equipment Vacuum Drying System NITS Automatic Welding System NITS TC/DSC Annulus Seal NITS Notes: 1. SSCs ITS are defined in 10 CFR 72.3 as those features of the ISFSI whose function is (1) to maintain the conditions required to store spent fuel safely, (2) to prevent damage to the spent fuel container during handling and storage, or (3) to provide reasonable assurance that spent fuel can be received, handled, packaged, stored, and retrieved without undue risk to the health and safety of the public. 2. Safety classification shall be per existing plant-specific requirements under the user's 10 CFR 50 heavy loads program.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-34 Table 2-4 Additional PWR and BWR Fuel A ssembly Design Characteristics 2 Pages Fuel Class WE 14x14 WE17x17 WE17x17 WE15x15 WE17x17 WE17x17 FA Design Doel 1&2 14x14 Doel 3 17x17 Doel 4 17x17 Tihange 1 15x15 Tihange 2 17x17 Tihange 3 17x17 Fuel Parameters No. of Rods 179 264 264 204 264 264 Active Fuel Length (in.)

96 145 169 145 145 169 Pellet Diameter (in.) 0.368 0.322 0.323 0.368 0.323 0.323 Fuel Rod Pitch (in.) 0.556 0.496 0.496 0.563 0.496 0.496 Clad OD (in.) 0.424 0.376 0.376 0.426 0.376 0.376 Clad Thickness (in.) 0.0225-0.030 0.0225 0.0225 0.0242 0.0225 0.0225 Guide and Instrument Tubes No. of Guide/Instrument Tubes 17 25 25 21 25 25 Guide/Instrument Tube Thickness (in.) 0.015 0.015 0.015 0.015 0.015 0.015 Fuel Class / BWR Fuel ID WE 14x14 WE 15x15 WE 17x17 GE-8-C (8 x 8) WE 17x17 WE 17x17 FA Design (1) (2) Kansai 14x14 Step I Type A Kansai 15x15 Step I Type A Kansai 17x17 Step II 8x8 Step II ENRESA ASCO 17x17 AM1000 17x17 Fuel Parameters No. of Rods 179 204 264 60 264 264 Active Fuel Length (in.)

143 143 144 146 144 165 Pellet Diameter (in.) 0.366 0.366 0.317 0.409 0.322 0.322 Fuel Rod Pitch (in.) 0.555 0.563 0.496 0.642 0.496 0.496 Clad OD (in.) 0.422 0.422 0.374 0.484 0.36 0.372 Clad Thickness (in.) 0.0225-0.030 0.0242 0.0225 0.036 0.0225 0.0225 Guide and Instrument Tubes No. of Guide/Instrument Tubes 17 21 25 4 (Note 3) 25 25 Guide/Instrument Tube Thickness (in.) 0.015 0.015 0.015 0.5015 (3) 0.015 0.015 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 2-36 Table 2-4a Potential for Fuel Reconfiguration Fuel Category Normal Off-Normal Accident Intact No No No Damaged No No Yes Failed Yes Yes Yes Table 2-4b Maximum Uranium Loadings per FFC for Failed PWR Fuel Fuel Assembly Class Maximum Uranium Loading (MTU) WE 17x17 0.550 CE 16x16 0.456 BW 15x15 0.492 WE 15x15 0.480 CE 15x15 0.450 CE 14x14 0.400 WE 14x14 0.410 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 3.9.2-10 3.9.2.1A EOS-37PTH DSC Failed Fuel Canister Up to four failed fuel canisters (FFCs) with failed fuel may be loaded in the EOS-37PTH basket with the remainder cells loaded with intact or damaged PWR fuel assemblies with or without control components (CCs).

The failed fuel is to be placed in individual FFCs in cells located at the corners of the interior 4x4 compartment cells of the EOS-37PTH basket, as shown in Figure 1F and 1H of the Technical Specifications. Each FFC is constructed of sheet metal and is provided with a welded bottom closure and a removable top closure. The failed fuel may be housed in a secondary container, such as a rod storage basket. The FFC is provided with screens at the top and bottom to contain fuel and allow filling and drainage of water from the FFC during loading operations. Drawing EOS01-1010-SAR shows the FFC design and the associated basket modifications.

The maximum fuel assembly load applied to each associated basket compartment location bounds the loads on the FFC. Therefore, the EOS-37PTH basket analyses with intact fuel are applicable when the basket is loaded with failed fuel. The FFC is protected by the basket fuel compartment tubes and its only function is to confine the failed fuel and allow its retrievability under normal and off-normal conditions. The empty FFC can be inserted by means of the tool that becomes threaded into the Bottom Lid. The handling of the loaded FFC is by means of lifting slots provided at the top of the FFC.

The FFC is evaluated for a load of 1.5g, which bounds the loads associated with lifting, handling and other normal and off-normal loads. The controlling stresses due to the 1.5g loading are compared to normal condition allowable stresses based on NF criteria [3.9.2-6]. Thermal loads for the FFC are not considered based on the following: (1) Subsection NF does not require evaluation of internal thermal stresses; (2) during lifting and handling, when primary stresses in the FFC are largest, there are no significant thermal gradients; (3) the more significant thermal gradients occur when the FFC is in the horizontal position when the transfer stresses occur, which are much lower than the lifting and handling stresses; and (4) similar thermal gradients and stresses occur in the basket, and are already qualified. The maximum allowable stresses based on a conservative temperature of 750 °F are shown in the following table:

FFC Allowable Stresses Stress Category Maximum Allowable Stress (ksi) Tensile / Combined Min (S m; S y) = 15.5 Bending 1.5 x S m = 23.2 Shear 0.6 x S m = 9.3 All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 3.9.2-11 Conservative hand calculations demonstrate that maximum handling stresses meet the allowable stress criteria. The controlling stresses and comparison to allowable stresses are summarized below:

FFC Summary of Stresses Location Type of Stress Calculated Stress (ksi)

Allowable Stress (ksi)

Stress Ratio Lifting Bottom Lid (Loaded FFC) Bending (center) 11.9 23.2 0.51 Insertion using Bottom Lid (Empty FFC) Shear (threads) 1.1 9.3 0.12 FFC Liner (Loaded FFC)

Tension (Center) 1.9 15.5 0.12 FFC Liner (Loaded FFC)

Shear (Lifting Slots) 7.5 9.3 0.81 Based on the summary above, the FFC meets the normal allowable stress criteria for a conservative lifting and handling load of 1.5g. Therefore, the structural integrity and retrievability of the FFC is ensured.

3.9.2.2 EOS-89BTH Basket Structural Evaluation for Normal/Off-Normal Loads The basis for the fuel compartment allowable stress values is the ASME Code,Section III, Subsection NG (Reference [3.9.2-1]), as given in Chapter 8.

3.9.2.2.1 General Description The EOS-89BTH DSCs consists of a shell assembly that provides confinement and shielding, and an internal basket assembly that locates and supports the FAs.

The basket is made up of interlocking slotted plates to form an egg-crate type structure. The egg-crate structure forms a grid of 89 fuel compartments that house boiling water reactor (BWR) SFAs. A typical stack-up of grid plates is composed of a structural steel plate, an aluminum plate for heat transfer and a

neutron absorber plate (neutron poison) for criticality. The DSC shell and basket assemblies are detailed in drawings in Section 1.3.2.

The descriptions in Section 3.9.2.1.1 of the transition rails and basket are also applicable to the EOS-89BTH DSC.

3.9.2.2.2 Key Dimensions and Materials The key basket dimensions and materials are per Drawings EOS01-1020-SAR and EOS01-1021-SAR Section 1.3.2.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 3.9.2-25 3.9.2.3A NUHOMS EOS-37PTH Type 4 Basket Evaluation The NUHOMS EOS-37PTH Type 4 (staggered plate) basket can accommodate up to a maximum of eight damaged fuel assemblies and up to a maximum of four loaded FFCs in designated basket compartments. The detailed description to the Type 4 Basket is discussed in Chapter 1.

3.9.2.3A.1 General Description The primary design change to EOS-37PTH Type 4 Basket is a modification to stagger the alignment of the steel, aluminum, and poison basket plates to ensure no continuous gaps across the compartments. With the addition of end caps for damaged fuel and a top lid for FFCs, the EOS-37PTH Type 4 Fuel Basket ensures that fuel is confined within the fuel compartment. 3.9.2.3A.2 Dimensions and Materials The change to the NUHOMS EOS-37PTH Type 4 Basket is accomplished by using aluminum plates that are 1 inch shorter than the steel/poison basket plates at the bottom of the basket assembly. The overall length, thickness or dimensions used in the structural evaluations (Section 3.9.2.1 and Section 3.9.2.3) remains same for the Type 4 Basket. Similarly, the materials in the EOS-37PTH Type 4 Basket are consistent with the structural analysis in Section 3.9.2.1 and Section 3.9.2.3. The key basket dimensions and materials are per Drawing EOS01-1010-SAR, as provided in Section 1.3.1. 3.9.2.3A.3 Temperature Thermal analyses to support the EOS-37PTH Type 4 Basket design are provided in Chapter 4, Appendix 4.9.6. The maximum bounding temperature for Type 4 Basket is 671 °F for the bounding HLZC 4 under the normal conditions (Chapter 4, Figure 4.9.6-4). The temperatures on the EOS-37PTH Type 4 basket is lower compared to the temperature of 798 °F (Figure 3.9.2-10) used in the structural analyses. The thermal analyses in Section 3.9.2.1 utilized a bounding steeper gradient and therefore envelop the EOS-37PTH Type 4 Basket thermal results. 3.9.2.3A.4 Fuel Weight The damaged or failed fuel weights are considered to be less than or equal to intact fuel weight for the pressurized water reactor PWR FA. Therefore, it is considered to be bounded.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 3.9.2-26 3.9.2.3A.5 Reconciliation The design change in the EOS-37PTH Type 4 Basket is a modification to stagger the alignment of the steel, aluminum, and poison basket plates. This change allows damaged, failed fuel or intact fuel assemblies to be loaded in an EOS-37PTH Type 4 Basket. Temperature distribution in the EOS-37PTH Type 4 Basket is bounded by the original analysis for Type 1 through 3. There are no changes to overall length, thickness or other structural dimensions of used in the structural evaluations. Therefore, no further analysis is required. The structural evaluation presented in Section 3.9.2.1 and Section 3.9.2.3 remains valid for EOS-37PTH Type 4 Basket.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 3.9.2-34 3.9.2-3 AREVA TN Technical Report, "Evaluation of Creep of NUHOMS Basket Aluminum Components under Long Term Storage Conditions", E-25768, Rev. 0 (Structural Integrity Associates, Inc. File No. TNI-20Q-302, Rev. 0).

3.9.2-4 NUREG/CR-1815, "Recommendations for Protecting Against Failure by Brittle Fracture in Ferritic Steel Shipping Containers Up to Four Inches Thick," U.S.

Nuclear Regulatory Commission, June 1981.

3.9.2-5 [ ] 3.9.2-6 American Society of Mechanical Engineers, "ASME Boiler and Pressure Vessel Code,"Section III, Division 1, Subsection NF, 2010 Edition with 2011 Addenda.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 4-1 4. THERMAL EVALUATION NOTE: For HLZCs 1 through 3, the basket types directly co rrelate to the Heat Load Zone Configurations (HLZCs), throughout this chapter, basket types are directly referred to by the HLZC.

For HLZCs 4 through 9, the basket types do not directly correlate to the HLZC. A summary of th e loading configuration for HLZCs 4 through 9 is presented below. A description of the various basket assembly types is presented in Chapter 1, Section 1.1.

The thermal evaluation described in this chapter is applicable to the NUHOMS EOS System that includes an EOS-37PTH or EO S-89BTH dry shielded canisters (DSCs) loaded inside the EOS-TC108, EOS-TC125 or EOS-TC135 transfer cask (TC) and the EOS horizontal storage module (HSM) or EOS-HSMS. With respect to thermal evaluations, the EOS-HSM and EOS-HSMS are identical; therefore, when the EOS-HSM is referred to in this chapter, the analysis is applicable to both the EOS-HSM and EOS-HSMS. A fl at plate support structure (FPS) is an option for the medium length EOS-HSM/HSMS, which allo ws a DSC support structure to be built up from a flat plate. This option is re ferred to as the EOS-HSM-FPS or EOS-HSMS-FPS. A summary of the EOS-37PTH and EOS-89BTH DSC configurations analyzed in this chapter is shown below:

DSC Type Basket Assembly Type or Heat Load Zone Configuration (HLZC) Max. Heat Load (kW) Transfer Cask Storage Module EOS-37PTH 1 50.00 EOS-TC125/ EOS-TC135 EOS-HSM/ EOS-HSMS/ EOS-HSM-FPS/ EOS-HSMS-FPS 2 41.80 EOS-TC125/ EOS-TC135/ EOS-TC108 3 36.35 EOS-89BTH 1 43.60 EOS-TC125 2 41.60 EOS-TC125/ EOS-TC108 3 34.44 Note 1: Basket Type 5 can only accommodate Intact FAs. Damaged FAs or loaded failed fuel canisters (FFCs) allowed per HLZC 8 shall only be loaded in Basket Type 4L. DSC Type Basket Assembly Type Heat Load Zone Configuration (HLZC) Max. Heat Load (kW) Transfer Cask Storage Module EOS-37PTH 4L/5 4 50.00 EOS-TC125/ EOS-TC135 EOS-HSM/ EOS-HSMS/ EOS-HSM-FPS/EOS-HSMS-FPS 4L/5 5 41.00 4L 6 46.00 4H 7 50.00 NUHOMS MATRIX (HSM-MX) 4L/5 8(1) 46.40 4L/5 9 37.80 EOS-89BTH 3 3 34.44 EOS-TC125/ EOS-TC108 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-1 Appendix 4.9.6 is newly added for Amendment 1. 4.9.6 THERMAL EVALUATION OF EOS-37PTH DSC FOR HLZC 4 THROUGH HLZC 9 This appendix evaluates the thermal performance of the EOS-37PTH Dry Shielded Canister (DSC) for normal, off-normal, and accident conditions with

Heat Load Zone Configurations (HLZCs) 4 through 9. For HLZCs 4 through 6, this appendix presents the thermal evaluation for both storage and transfer operations. For HLZCs 7 through 9, this appendix only presents the thermal evaluation for transfer operations. Storage evaluation for HLZCs 7 through 9 is

presented in Chapter A.4.

Thermal Evaluation of EOS-37PTH DSC for HLZCs 4, 5 and 6 4.9.6.1For HLZCs 4 and 5, only intact fuel assemblies (FAs) are allowed. For HLZC 6, damaged FAs or failed fuel canisters (FFCs) can be loaded along with intact FAs. A summary of the EOS-37PTH DSC configurations analyzed in this

section is shown below.

DSC Type Basket Assembly Type Heat Load Zone Configuration (HLZC) Max. Heat Load (kW) Transfer Cask Storage Module EOS-37PTH 4L/5 4 50.00 EOS-TC125/

EOS-TC135 EOS-HSM/ EOS-HSMS/ EOS-HSM-FPS/ EOS-HSMS-FPS 4L/5 5 41.00 4L 6 46.00 HLZCs 4 and 5 evaluated in this section can be loaded in an EOS-37PTH DSC equipped with either Basket Assembly Type 4L or 5. HLZC 6 shall only be loaded on Basket Assembly Type 4L as discussed in Chapter 1, Section 1.1 since it has the capability to store damaged FAs and FFCs. The various basket assembly types within the EOS-37PTH DSC are described in Chapter 1, Section 1.1 and the various system configurations allowed for these basket assembly types are listed in Table 1-2. Section 4.9.6.1.1 presents a discussion on the differences in the thermal performance between the different basket

types. Based on the discussion in Section 4.9.6.1.1, both of these basket assembly variants have identical thermal performance. Section 4.9.6.1.2 presents descriptions of HLZCs 4, 5 and 6. Section 4.9.6.1.3 presents the evaluation of HLZCs 4, 5 and 6 with intact FAs. Sections 4.9.6.1.5 and 4.9.6.1.6 present the evaluation of HLZC 6 with damaged FAs and FFCs , respectively.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-5 Appendix 4.9.6 is newly added for Amendment 1.

4.9.6.1.2 Description of HLZCs 4, 5, 6 HLZCs 4, 5 and 6 are shown in Figure 1D, Figure 1E and Figure 1F of [4.9.6-1], respectively. HLZC 4 with a maximum heat load of 50 kW, HLZC 5 with a maximum heat load of 41.0 kW, and HLZC 6 with a maximum heat load of 46.0 kW are evaluated. Only intact FAs can be loaded in HLZC 4 and HLZC

5. As shown in Figure 1F of [4.9.6-1], HLZC 6 can accommodate up to eight damaged FAs, or up to four FFC s, along with intact FAs. It should be noted that damaged FAs and FFCs shall not be stored in the same DSC. As shown in Figure 1D of [4.9.6-1], HLZC 4 maintains the maximum heat load of the DSC at 50 kW similar to HLZC 1 (Figure 1A of [4.9.6-1]) but reduces the maximum heat load per FA to 1.625 kW from 2.0 kW in HLZC 1. To accommodate FAs with decay heat loads greater than 1.625 kW, an additional

HLZC is evaluated. As shown in Figure 1E of [4.9.6-1], HLZC 5 can accommodate FAs up to 2.4 kW. The maximum heat load per DSC for HLZC 5 is limited to 41.0 kW.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-15 Appendix 4.9.6 is newly added for Amendment 1.

4.9.6.1.5.4 Results and Conclusions Table 4.9.6-9 shows the maximum temperatures of the intact fuel cladding along with the maximum and average temperatures for the various components within the EOS-37PTH DSC and the EOS-TC125 for the bounding transfer accident condition with eight damaged FAs. It also compares them to the design basis evaluation from Section 4.5 with intact FAs. As shown in Table 4.9.6-9, the maximum temperatures for fuel cladding and basket plates increase. However, the maximum fuel cladding temperature remains below the allowable temperature limits of 1058 °F. There are no temperature limits for

the basket plates. To evaluate the impact on internal pressure, the average helium temperature is calculated using the approach presented in Section 4.7.1.2 accounting for the changes due to the damaged FAs turning into rubble at the bottom of the DSC during accident condition. The average helium temperature for the bounding accident condition is 633 K for the short DSC cavity. This is lower than the average helium temperature of 653 K (Table 4-45) used to determine the maximum internal pressure for the bounding hypothetical accident condition with intact FAs. Therefore, the maximum internal pressure during the bounding accident condition with damaged FAs are bounded by the evaluation performed with intact FAs listed in Table 4-45. Since the temperature criteria along with the internal pressure criteria are satisfied, no further evaluations are required to load damaged FAs in the EOS-37PTH DSC with HLZC 6. Figure 4.9.6-7 shows the temperature

contours for the EOS-37PTH DSC with HLZC 6 in the EOS-TC125 with 29 intact/eight damaged FAs during accident transfer condition.

4.9.6.1.6 Evaluation for FFCs in HLZC 6 HLZC 6 can accommodate a combination of intact FAs along with FFCs. It can be loaded with up to four FFCs as noted in Section 4.9.6.1.2. This section presents the thermal evaluation of the EOS-37PTH DSC with Basket Type 4L

for HLZC 6 with intact FAs and FFCs during storage and transfer conditions.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final SafRev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-16 Appendix 4.9.6 is newly added for Amendment 1.

4.9.6.1.6.1 Description of Load Cases 4.9.6.1.6.2 Ambient Operating Conditions All ambient operating conditions are identical to those described in Section 4.5.1 for LC 1.

4.9.6.1.6.3 CFD Modeling All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-17 Appendix 4.9.6 is newly added for Amendment 1.

4.9.6.1.6.4 Results and Conclusions Table 4.9.6-10 shows the maximum temperatures of fuel cladding and various components for the bounding normal and off-normal transfer conditions based

on HLZC 6 with four FFCs. It also compares the maximum temperatures with the results from HLZC 4 evaluated in Section 4.9.6.1.4. As shown in Table 4.9.6-10, the maximum fuel cladding temperature for the intact FAs is 701 °F, and remains below the allowable limit of 752 °F. In addition, the maximum temperatures determined for HLZC 6 with FFCs are lower compared to that of HLZC 4. This is because a comparison of HLZC 4 in Figure 1D of [4.9.6-1], and HLZC 6 in Figure 1F of [4.9.6-1] shows that both HLZCs have identical zoning and that HLZC 6 is a subset of HLZC 4.

Both the total heat load of the DSC and the heat load of each individual FA within HLZC 6 are bounded by HLZC 4. Therefore, the time limits mentioned in Item A of Section 4.9.6.1.4.4 are also applicable for transfer operations of

HLZC 6 with FFCs. Figure 4.9.6-8 shows the temperature contours of the EOS-TC125 loaded with

the EOS-37PTH DSC based on HLZC 6 with FFCs. To evaluate the impact on internal pressure, the average helium temperature is calculated using the approach presented in Section 4.7.1.2 accounting for the

changes due to the FFCs. For the bounding normal condition at 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months , the average helium temperature within the DSC cavity is 517 °F (543 K) and is lower compared to the design basis value of 557 °F (565 K) (see Table 4-45)

used to evaluate the internal pressure. Therefore, it is concluded that there is no impact on the internal pressure for normal and off-normal conditions.

Since the FFCs are conservatively modeled as helium for normal and off-normal conditions, no other changes are expected for accident conditions within the FFCs. Therefore, the maximum accident temperatures determined for HLZC 4 in Section 4.9.6.1.4 will remain bounding for HLZC 6, and no further

evaluation is required. Similar to the transfer conditions, the maximum temperatures for storage operations with HLZC 4 will bound HLZC 6, since the same DSC configuration is considered for storage. Therefore, no further evaluations are

required for storage operations.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-18 Appendix 4.9.6 is newly added for Amendment 1. Based on this discussion, all the temperature criteria along with the internal pressure criteria are satisfied for storage of the EOS-37PTH DSC with HLZC 6

with intact FAs and FFCs. Thermal Evaluation of EOS-37PTH DSC for HLZCs 7, 8, and 9 4.9.6.2 HLZCs 7, 8, and 9 are shown in Figure 1G, Figure 1H, and Figure 1I of [4.9.6-1], respectively. For HLZCs 7 and 9, only intact FAs are allowed. For HLZC 8, damaged FAs or FFCs can be loaded along with intact FAs. A summary of the EOS-37PTH DSC configurations for HLZCs 7 through 9 is

shown below:

DSC Type Basket Assembly Type Heat Load Zone Configuration (HLZC) Max. Heat Load (kW) Transfer Cask Storage Module EOS-37PTH 4H 7 50.00 EOS-TC125/

EOS-TC135 HSM-MX 4L/5 8 (1) 46.40(2)4L/5 9 37.80 Note: 1. Basket Type 5 can only accommodate intact FAs. Damaged FAs or FFCs allowed per HLZC 8 shall only be loaded in Basket Type 4L. 2. The maximum decay heat per DSC is limited to 41.8 kW when a damaged FA or failed fuel is loaded. Storage Operations Thermal evaluation for HLZCs 7 through 9 for storage in the HSM-MX is presented in Chapter A.4.

Transfer Operations A comparison of HLZC 7 in Figure 1G of [4.9.6-1] with HLZC 4 in Figure 1D of [4.9.6-1] shows that the maximum heat loads in the inner zones (Zones 1 and

2) for HLZC 7 are lower than HLZC 4. Based on the study in [4.9.6-2],

maximizing the heat loads of the inner zones is conservative. In addition, HLZC 7 is only permitted in Basket Assembly Type 4H, whereas Basket Assembly Type 4L/5 is considered in Section 4.9.6.1.4 to evaluate transfer operations for HLZC 4. Basket Type 4H has a higher thermal performance compared to Basket Assembly Type 4L/5 based on the discussion in Section 4.9.6.1.1. Based on this discussion, the thermal evaluation of HLZC 4 in Section 4.9.6.1.4 for transfer operations is bounding for HLZC 7, including the transfer time limits.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-19 Appendix 4.9.6 is newly added for Amendment 1. The maximum heat load per DSC for HLZC 8 is limited to 46.4 kW, which is lower compared to the maximum heat load of 50 kW for HLZC 4. In addition, while only loading intact FAs, the heat loads in each zone of HLZC 8 are bounded by HLZC 4. Based on this discussion, the thermal evaluation of HLZC 4 in Section 4.9.6.1.4 for transfer operations is bounding for HLZC 8, including the transfer time limits while loaded with intact FAs. In addition, the maximum heat load for HLZC 8 while loaded with damaged or FFCs is limited to 41.8 kW compared to 46.0 kW for HLZC 6. Therefore, the thermal evaluation presented for HLZC 6 in Section 4.9.6.1.5 with damaged

FAs, and Section 4.9.6.1.6 with failed fuel remains bounding for HLZC 8. Similarly, the maximum heat load per DSC for HLZC 9 is limited to 37.80 kW, which is lower compared to the maximum heat load of 41.0 kW for HLZC 5.

In addition, the maximum heat load per FA within zone 3 of HLZC 9 is reduced to 2.0 kW compared to 2.4 kW in HLZC 5. Since the total heat load per DSC and the maximum heat load per FA are lower, the thermal evaluation of HLZC 5 in Section 4.9.6.1.4 for transfer operations is bounding for HLZC 9, including the transfer time limits while loaded with intact FAs. Time limits for transfer operations of the EOS-37PTH DSC with HLZCs 7, 8, and 9 are listed in Table 4.9.6-7.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-30 Appendix 4.9.6 is newly added for Amendment 1.

Table 4.9.6-10 Maximum Component Temperatures of EOS-37PTH DSC for HLZC 6 with Four FFCs Transfer Conditions Normal/Off-normal, Hot, Indoor, Transient, No Air Circulation DSC EOS-37PTH DSC Heat Load (kW) 50 44.3 FA Type 37 Intact 33 Intact/ 4 Failed T (=THLZC6-THLZC4) HLZC 4 (1) 6 Component (2) Temperature (°F )

Fuel Cladding 729 701 -28 Basket Plate 671 646 -25 Transition Rail 547 522 -25 DSC Shell 480 459 -21 Lead ( Gamma Shield) 311 297 -14 Bottom Neutron Shield (Average) 223 222

-1 Neutron Shield (Average) 210 204

-6 Notes: (1) Temperatures are obtained from Table 4.9.6-5. (2) All temperatures are reported at 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months .

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-46 Appendix 4.9.6 is newly added for Amendment 1.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. TBD, TBD August 2018 Revision 2 72-1042 Amendment 1 Page 4.9.6-47 Appendix 4.9.6 is newly added for Amendment 1.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 5-2 Confinement Boundary 5.1 The EOS-37PTH and EOS-89BTH DSCs are high integrity stainless steel or duplex steel welded vessels that provide confinement of radioactive materials, encapsulate the fuel in a helium atmosphere, and provide biological shielding dur ing DSC closure and transfer and storage operations. The DSCs are designed to maintain confinement of radioactive material within the limits of 10 CFR 72.104(a), 10 CFR 72.106(b) and 10 CFR 20 under normal, off-normal, and credible accident conditions. Chapter 3 and

associated appendices conclude that the design, including the helium atmosphere within the DSC, will adequately protect the spent fuel cladding against degradation that might otherwise lead to gross ruptures during storage. The design ensures that

fuel degradation during storage will not pose operational safety problems with respect to removal of the fuel from storage. The confinement boundary is shown in Figure 5-1. Because confinement is provided by the "leaktight" DSC, storage of damaged and failed fuel does not affect radioactive material release from the DSC. The DSC cylindrical shell, the inner top cover and inner bottom cover form the confinement bounda ry for the spent fuel. The drain port cover, vent plug and welds are also incl uded in the confinement boundary. The outer top cover plate is an attachment to the confinement boundary that provides bearing to help support the inner top cover plate, a nd is therefore subject to ASME Code Subsection NB per ASME Figure NB-1132.2-3 note 6. The outer bottom cover plate is not needed to support the inner bottom c over plate under design pressure and is not in the component support path. It is thus outside ASME Code jurisdiction per ASME Figure NB-1132.2-2 note 5 and NB-2190(b). The dimensions and material descriptions for the confinement boundary assemblies and the redundantly welded barriers are discussed in Chapter 1. The components important-to-safety are identified in Chapter 2.

For damaged fuel assemblies, top and bottom end caps are provided to contain any potential fuel debris in the fuel compartment.

Failed fuel shall be stored in a failed fuel canister (FFC). The end caps fit snugly into the top and bottom of the fuel compartment. They are held in place by the fuel compartments and the inner bottom cover plate and the top shield plug duri ng transfer and storage. The end caps and FFCs have multiple through holes to permit unrestricted flooding and draining of the fuel compartments.

5.1.1 Boundary

Definition/Design Features The cylindrical shell to bottom cover plate welds are made during fabrication of the DSCs, and are fully compliant with ASME Section III, Subsection NB. The welds between the cylindrical shell and inner top cover (including drain port cover and vent plug welds) are made after fuel loading. These welds are designed, fabricated, inspected, and tested using alternatives to the ASME code specified in Section 4.4.4 of the Technical Specifications [5-3].

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 6-2 6.1 Discussions and Results The following is a summary of the methodology and results of the shielding analysis of the EOS system. More detailed information is presented in the body of the chapter. The EOS-37PTH DSC stores up to 37 PWR FAs, while the EOS-89BTH stores up to 89 BWR FAs. Each EOS-DSC is configured into heat load zones in order to optimize the system performance for both thermal and shielding considerations.

Nine heat load zoning configurations (HLZCs) are available for the EOS-37PTH DSC, and three HLZCs are available for the EOS-89BTH DSC. The HLZCs are defined in the Technical Specifications (TS), Figure 1A through Figure 2 [6-11].

Fuel to be stored is limited by the decay heat and minimum cooling times defined in the Technical Specifications. The EOS-37PTH DSC is authorized to store up to eight damaged FAs or four FFCs using HLZC 6 or HLZC 8. Damaged and failed fuel shall not be present in the same DSC. Source Terms The ORIGEN-ARP module of the Oak Ridge National Laboratory (ORNL)

SCALE6.0 code package [6-1] is used to develop reasonably bounding gamma and neutron source terms.

[] Control components (CCs) are allowed to be stored within a PWR FA. Examples of CCs include burnable poison rod assemblies (BPRAs) and thimble plug assemblies.

Control components typically have a Co-60 source because of its light element activation, which contributes substantially to the dose rates. The CC source term is provided in Table 6-37. CCs should be limited as follows:

All FAs: 308 Ci Co-60 per CC in the active fuel region

Inner FAs: 63.0 Ci Co-60 per CC in the combined plenum/top region

Peripheral FAs: 24.3 Ci Co-60 per CC in the combined plenum/top region The inner and peripheral FAs are defined in Figure 6-1 and are applicable to all PWR HLZCs. All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 6-3 BWR fuel does not include CCs other than the fuel channel, which is conservatively included in the source term. The BWR fuel channel is fabricated from zirconium alloy and does not require a Co-60 limit because the contribution to the source term from the fuel channel is negligible.

Dose Rates The Monte Carlo transport code, MCNP5 [6-5], is used to compute dose fields around the EOS-TCs and EOS-HSM using detailed three-dimensional models for the following normal configurations:

EOS-37PTH DSC inside the EOS-TC108

EOS-37PTH DSC inside the EOS-TC125/135

EOS-37PTH DSC inside the EOS-HSM-Short

EOS-89BTH DSC inside the EOS-TC108

EOS-89BTH DSC inside the EOS-TC125/135

EOS-89BTH DSC inside the EOS-HSM-Medium The change on this page is related to Enclosure 3 Changes Not Associated with the RSIs, Change 2.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 6-9 The EOS-DSC baskets are zoned by heat load. Heat load zoning allows hotter FAs, which generally have larger neutron and gamma source terms, to be placed in the inner

zones and be shielded by FAs in the outer zone. The EOS-TC108 and EOS-TC125/135 have different heat load zone configurations because the EOS-TC125/135 is more heavily shielded than the EOS-TC108 and can therefore be

loaded with stronger sources.

Nine HLZCs are available for the EOS-37PTH DSC and three HLZCs are available for the EOS-89BTH DSC. These HLZCs are defined in the TS, Figure 1A through Figure 2 [6-11]. All HLZCs may be transferred in the EOS-TC125/135, while the EOS-TC108 is limited to PWR HLZCs 2 and 3 and BWR HLZCs 2 and 3. The EOS-HSM may store PWR HLZCs 1 through 6 and all BWR HLZCs. The bounding HLZCs are used for dose rate analysis. Dose rates are generally larger for higher heat loads, and radial dose rates are dominated by fuel in the peripheral regions. For BWR fuel, it is determined by inspection that HLZC 1 is bounding for the EOS-TC125/135 and HLZC 2 is bounding for the EOS-TC108. For PWR fuel, it is also determined by inspection that HLZC 2 is bounding for the EOS-TC108. For PWR fuel in the EOS-TC125/135, the bounding HLZC cannot readily be determined by inspection, although the nine HLZCs may be reduced to three candidates based on head load considerations. HLZC 4 has the largest total heat load in the peripheral zone, HLZC 1 has a large heat load in an inner zone, and HLZC 5 has the largest heat load per fuel assembly. Therefore, each of these HLZCs is examined explicitly.

Based on MCNP scoping calculations, HLZC 4 bounds HLZC 1, and HLZC 4 and HLZC 5 result in similar peak dose rates for the EOS-TC125/135 and EOS-HSM. However, HLZC 4 results in larger average dose rates on the EOS-TC125/135 side surface compared to HLZC 5 because HLZC 4 has the largest heat load in the peripheral zone. Therefore, HLZC 4 is used in design basis PWR calculations for the EOS-TC125/135 and EOS-HSM. Source terms for HLZC 4 are derived for 1.0 kW/FA in Zone 1 and 1.625 kW/FA in Zones 2 and 3 for a total DSC heat load of 52.0 kW. This bounds the maximum DSC heat load of 50.0 kW.

Note that up to eight damaged PWR fuel assemblies or up to four FFCs are authorized for HLZC 6 and HLZC 8. Source terms are also developed for a damaged/failed fuel HLZC that bounds both HLZC 6 and 8. These source terms are derived for 1.0 kW/FA in Zone 1, 1.5 kW/FA in Zone 2, 1.5 kW/FA for intact fuel in Zone 3, and 0.85 kW/FA for failed fuel in Zone 3. The methodology for developing damaged/failed fuel source terms is the same as used for developing intact fuel source terms.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 6-26 Damaged or Failed Fuel, Normal and Off-Normal Conditions Damaged or failed fuel may be tranferred in the EOS-37PTH DSC and EOS-TC125/135 using HLZC 6 or 8. Up to eight damaged fuel assemblies may be loaded in Zone 2, or up to four failed fuel canisters (FFCs )in Zone 3. Damaged and failed fuel may not be present in the same DSC. Damaged or failed fuel is not authorized for storage in the EOS-89BTH DSC or transfer in the EOS-TC108.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 6-27 Accident Conditions Accident models are also developed for the four transfer configurations. In the accident models, the water neutron shield, neutron shield panel, and borated polyethylene bottom neutron shield are replaced with void, and the accident source terms are used. The dose rate is calculated at a distance of 100 m from the EOS-TC.

Ground is modeled to account for ground scatter at large distances.

6.3.3 MCNP Model Geometry for the EOS-HSM Detailed EOS-HSM MCNP models are developed for the following two

configurations:

EOS-HSM-Short with EOS-37PTH DSC

EOS-HSM-Medium with EOS-89BTH DSC The EOS-37PTH DSC and EOS-89BTH DSC models developed in Section 6.3.2 are used in the EOS-HSM models. Consistent with the EOS-DSC models, the Z-axis in the EOS-HSM models is along the length of the EOS-DSC. Because the DSC cavity has been reduced in length to match the length of the fuel, the EOS-37PTH DSC model is shorter than the EOS-89BTH DSC model. Short, medium, and long versions of the EOS-HSM may be used, depending on the length of EOS-DSC to be stored.

The EOS-HSM modeled is the smallest EOS-HSM that fits the EOS-DSC. Therefore, the EOS-HSM-Short is modeled with the EOS-37PTH DSC and the EOS-HSM-Medium is modeled with the EOS-89BTH DSC.

The EOS-HSM features two DSC support structure designs. The original design utilizes I-beams, while an alternate design utilizes a flat plate system. These options do not affect the bulk shielding provided by the EOS-HSM, and the I-beam supports are represented in the MCNP models.

PWR source terms (without CCs) are provided in Table 6-17 through Table 6-19, and the CC source provided in Table 6-37 is added to these PWR source terms for all FAs.

BWR source terms are provided in Table 6-27 through Table 6-29. For the active fuel

regions, an axial source distribution is applied per Table 6-30 and Table 6-31 for PWR and BWR fuel, respectively. For the top nozzle, plenum, and bottom nozzle regions, the source is evenly distributed throughout the region.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-1 7. CRITICALITY EVALUATION NOTE: The referenced basket types throughout this chapter are based on the boron content in the poison plates. The term "basket types" in this chapter differs from the definition of the basket types in Chapter 1. The correlations between the basket types used in this chapter and the basket types identified in Chapter 1 are clarified below:

Basket Type Identification in Chapter 1 and Technical Specifications

[7-8] Basket Type Identification in Chapter 7 EOS-37PTH A1/A2/A3/A4H/A4L/A5 A B1/B2/B3/B4H/B4L/B5 B EOS-89BTH A1/A2/A3 M1-A B1/B2/B3 M1-B C1/C2/C3 M2-A The design criteria for the NUHOMS EOS System dry shielded canisters (DSCs) require that the fuel loaded in the EOS-37PTH and EOS-89BTH DSCs remain subcritical under normal, off-normal and accident conditions as defined in 10 CFR Part 72. The criticality analyses performed to demonstrate that these DSCs loaded with intact, damaged or failed fuel in the EOS-37PTH DSC, or loaded with intact fuel in the EOS-89BTH DSC satisfy the stated requirements are presented in this chapter. Failed fuel shall be loaded into a failed fuel canister (FFC) and include failed fuel assemblies (FAs), rods, rod segments, pellets, and debris.

The DSCs consist of a shell assembly, an internal basket assembly, and extruded aluminum open section transition rails that provide the transition to a cylindrical exterior surface to match the inside surface of the shell. The EOS-37PTH DSC is designed to store and transport up to 37 pressurized water reactor (PWR) FAs with or without control components (CCs) while the EOS-89BTH is designed to store and transport up to 89 boiling water reactor (BWR) FAs with and without channels. The DSCs are of variable length to match the length of the fuel and CCs, as applicable, to be stored. The basket is composed of interlocking slotted plates to form an egg-crate type structure. The egg-crate structure forms a grid of 37 or 89 fuel compartments that house the spent fuel assemblies (SFAs). The egg-crate structure is composed of steel alloy, aluminum alloy, and poison plates.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-3 7.1 Discussion and Results This section presents a general description of system application and criticality model for each DSC. The maximum allowable fuel enrichments as a function of basket type are specified for BWR and PWR fuel. Additionally, the minimum soluble boron concentrations (ppm) for the PWR fuel are also presented for each basket type. The results of the evaluations demonstrate that the maximum calculated keff , including statistical uncertainty, are less than the upper subcritical limit (USL) determined from a statistical analysis of benchmark criticality experiments. The statistical analysis procedure includes a confidence band with an administrative safety margin of 0.05.

EOS-37PTH The EOS-37PTH DSC consists of a shell assembly, which provides confinement and shielding, and an internal basket assembly, which locates and supports the PWR FAs.

A detailed description of the DSC and Basket is found in Chapter 1, Section 1.2.1.1. The FAs evaluated for storage in the EOS-37PTH DSC are considered intact , damaged, or failed. The authorized FAs are presented in Chapter 2. The payload of the EOS-37PTH DSC may include CCs that are contained within the FA. The authorized CCs are listed in Chapter 2. Reconstituted fuel assemblies with replacement rods that displace an equal amount of water as the original rods are also authorized for storage and are bounded by the intact fuel, for criticality purposes.

Also, a below capacity loading or short-loading as shown in Figure 7-13, is allowed for storage in the EOS-37PTH DSC. A maximum of 37 intact FAs can be stored in the EOS-37PTH DSC. In addition, a maximum of eight damaged FAs or four FFCs loaded with failed FAs or failed fuel debris, balanced with intact FAs, can be accommodated in the EOS-37PTH DSC. The loading plans are shown in Figures 1F and 1H of the Technical Specifications [7-8]. All failed fuel shall be stored in an FFC. Secondary containers, such as rod storage baskets, shall be placed in an FFC. No credit is taken for the FFC or any secondary containers, although all secondary containers must be designed to allow drainage.

The criticality analysis performed uses the most reactive configuration for intact fuels to determine the maximum allowable enrichment of 37 intact fuels stored in the EOS-37PTH DSC for each FA class, as a function of soluble boron and basket type, with and without CCs. The results are presented in Table 7-3.

Additionally, the most reactive configuration between damaged and failed fuels is used to determine the maximum allowable enrichment of up to eight damaged fuels or four failed fuels stored in the EOS-37PTH DSC with intact fuels, for each FA class, as a function of soluble boron and basket type, with and without CCs. The results are presented in Table 7-51.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-5 7.2 Package Fuel Loading EOS-37PTH The EOS-37PTH DSC is designed to accommodate the FAs listed in Chapter 2. Since the assemblies listed represent a wide range of fuel types and configurations, it is demonstrated first that the most reactive case is obtained for each fuel class. In this context, the fuel class is defined as a set of fuel assembly designs with the same array size and rod pitch or rod outer diameter. The most reactive case for each class is used to determine the maximum allowable enrichments for intact, damaged, and failed fuel. The payload of the EOS-37PTH DSC may include CCs that are contained within the FA. The authorized CCs are listed in Chapter 2. The only change to the package fuel loading required to evaluate the addition of the CCs is to replace the borated water in the water holes with CC materials. Since the CCs displace the borated moderator in the assembly guide and/or the instrument tubes, an evaluation is performed to determine the potential impact of the storage of CCs that extend into the active fuel region on the system reactivity. CCs that extend into the active fuel regions, such as burnable poison rod assemblies (BPRAs), control rod assemblies (CRAs), axial power shaping rod assemblies (APSRAs), control element assemblies (CEAs), and neutron source assemblies (NSAs) are conservatively assumed to exhibit the neutronic properties of 11 B 4C (no credit taken for B-10 content). Since the criticality analysis models simulate only the active fuel height, any CC that is inserted into the FA in such a way that it does not extend into the active fuel region is considered as authorized for storage without adjustment to the soluble boron content or initial enrichment, as required for CCs that extend into the active fuel region.

EOS-89BTH The EOS-89BTH DSC is designed to accommodate the FAs listed in Chapter 2. Since the assemblies listed represent a wide range of fuel types and configurations, a representative FA is determined by comparing keff values for the FAs listed, with and without various thicknesses of channels. The representative FA is used to obtain the maximum allowable enrichment as a function of basket type. The maximum allowable enrichment is obtained using the GNF2 10x10 FA, except for the KKL-BWR 11/16 and SVEA-96Opt2 FAs, classified with a BWR fuel identification of ABB-10-C, in Table 7-39. The maximum allowable enrichment requirements for these two assembly designs are also specified in Table 7-4.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-6 7.3 Model Specification The following sections describe the physical models and materials of the EOS-37PTH and EOS-89BTH DSCs as loaded and transferred in the EOS transfer casks (TCs) (i.e.,

EOS-TC108, -TC125 or -TC135) used for input to KENO V.a. module of the CSAS5 sequence of SCALE 6.0 [7-1] to perform the criticality evaluation. The reactivity of the canister under storage conditions is bounded by the EOS-TC analysis with a zero internal moderator density case, which bounds the storage conditions in the horizontal storage module (HSM) because: (1) the canister internals are always dry (purged and backfilled with helium) while in the HSM, and (2) the EOS-TC contains materials such as steel and lead, which provide close reflection of fast neutrons back into the basket, while the HSM materials (concrete) are much further from the sides of the DSC and thereby tend to reflect thermalized neutrons back to the canister, which are absorbed in the canister materials, reducing the system reactivity.

7.3.1 Description

of Criticality Analysis Model EOS-37PTH The EOS-TC and DSC are explicitly modeled using the appropriate geometry options in the KENO V.a module, of the CSAS5 sequence of SCALE 6.0. Several models are

developed to evaluate the fabrication tolerances of the DSC, FA type and physical conditions (intact, damaged, and failed), assembly location, initial enrichment, fixed poison loading, soluble boron concentration, and storage of CCs with the fuel.

The criticality evaluation is performed using a basket section equivalent to the active fuel height with periodic axial boundary conditions, which effectively makes the model infinitely tall. The key basket dimensions utilized in the calculation are shown

in Table 7-5. The basic KENO model, with a length equivalent to the active fuel height, is modeled with periodic boundary conditions axially, and reflective boundary conditions radially. The axial section essentially models an infinite active fuel height DSC. The model does not explicitly include the water neutron shield; however, the infinite array of casks without the neutron shield is conservatively modeled with unborated water between the casks and in the TC/DSC annulus. For the purpose of storage, the configuration is not expected to encounter any regions containing fresh water once the FAs are loaded. Therefore, this hypothetical configuration that models an infinite array of casks in close reflection is conservative.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-12

7.4 Criticality

Calculation This section describes the various criticality evaluations carried out for the NUHOMS EOS System DSCs. The analyses are performed with the CSAS5 module of the SCALE 6.0 code system. The most reactive configuration for each DSC is determined with consideration of fabrication tolerances, FA location, and basket dimensions important to criticality. A series of calculations is performed to determine the relative reactivity of the various FA designs to determine the most reactive assembly type. Additional analyses are performed to determine the relative reactivity of the various damaged and failed fuel configurations for the EOS-37PTH DSC. Finally, the maximum allowable enrichment for the minimum required criticality control mechanism, which is soluble boron and basket type for PWR FAs, and basket type for BWR FAs, is determined for the respective authorized loadings. EOS-37PTH

[ ] All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-13

[ ] EOS-89BTH

[] 7.4.1 Calculational Method 7.4.1.1 Computer Codes The CSAS5 control module of SCALE 6.0 [7-1], is used to calculate the effective multiplication factor (keff) of the fuel in the TC (bounds fuel in HSM). The CSAS5 control module allows simplified data input to the functional modules BONAMI, NITAWL, and KENO V.a. These modules process the required cross sections and calculate the keff of the system. BONAMI performs resonance self-shielding calculations for nuclides that have Bondarenko data associated with their cross

sections. NITAWL applies Nordheim resonance self-shielding correction to nuclides having resonance parameters. Finally, KENO V.a calculates the k eff of a three-dimensional system. Enough neutron histories are run so that the standard deviation is below 0.0010 for all calculations.

7.4.1.2 Physical and Nuclear Data The physical and nuclear data required for the criticality analysis include the FA data

and cross section data as described below. The pertinent data for criticality analysis for each FA evaluated in the EOS-37PTH DSC and EOS-89BTH DSC are listed in Chapter 2. The criticality analysis uses the

44-group cross section library built into the SCALE 6.0 system. Oak Ridge National

Laboratory used ENDF/B-V data to develop this broad-group library, specifically for the criticality analysis of a wide variety of thermal systems.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-14 7.4.1.3 Bases and Assumptions

[]The following assumptions are employed in the criticality calculations.

EOS-37PTH and EOS-89BTH Fresh fuel is assumed. No credit is taken for fissile depletion, fission product poison, or burnable absorbers. For intact fuels, fuel rods are filled with full density fresh water in the pellet-clad gap. The neutron shield and steel neutron shield jacket (outer skin) of the cask are conservatively removed and infinite arrays of casks are pushed close together with external moderator (unborated water) in the interstitial spaces. The MMC poison plates are modeled with minimum specified B-10 content required for safety. Temperature is 20 °C (293K). All steel and aluminum alloys of the basket structure are modeled as SS304 and aluminum, respectively. While these compositions, which are provided in the SCALE 6.0 standard composition library, have small differences with compositions of the various steels and aluminum, they have negligible effect on the results of the calculation. All zirconium-based materials in the fuel are modeled as Zircaloy-4 for PWR and Zircaloy-2 for BWR fuel evaluations. The small differences in the composition of the various clad/guide compartment materials have negligible effect on the results of the calculations. Omission of grid plates, spacers, and hardware in the FA. No integral burnable absorbers, such as gadolina, erbia or any other absorbers, are included. The fuel rods are modeled assuming a stack density of 97.5% theoretical density with no allowance for dishing or chamfer in the fuel rod model, which conservatively bounds the total fuel content in the FA authorized for storage.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-15 EOS-37PTH Only Non-fuel assembly hardware that extends into the active fuel regions, such as BPRAs, CRAs, APSRAs, CEAs, and NSAs, are conservatively assumed to exhibit the neutronic properties of 11 B 4 C (no credit taken for B-10 content). There is negligible neutron absorption from any of this hardware and it is collectively

referred to as CCs. Water in the EOS-37PTH DSC cavity contains soluble boron at optimum density.

The soluble boron is mixed with the moderator. By varying the moderator density from 50% to 100% of full density, the density of water at which the reactivity is maximized is determined. The maximum planar average initial fuel enrichment is modeled as uniform everywhere throughout the assembly. Natural uranium blankets and axial or radial enrichment zones are modeled as enriched uranium at the planar average initial enrichment. The portion of the DSC corresponding to the axial length of the active fuel is modeled for the criticality analysis. The axial ends of the DSC are not modeled.

In addition, the damaged and failed FA criticality calculations also employ the following assumptions for the EOS-37PTH DSC: Single-ended shear assumes one row of fuel rods is displaced to a new location. Double-ended shear assumes that the selected sheared row displaced with a single-ended shear is further split axially to result in an "extra" row of fuel rods. Bent or bowed fuel rods assume that the fuel is intact but that the rod pitch is allowed to vary from its nominal fuel rod pitch. Fuel assembly lattices with less fuel rod assume missing fuel rods. Full fuel rod lattices assume that guide and instrument tubes are replaced with fuel rods (failed fuel assumption). De-cladded fuel rods assume severe cladding damage (failed fuel assumption). No credit is taken for FFCs (failed fuel assumption). Both damaged and failed FAs are modeled as failed (total of 12), which is highly conservative because damaged and failed fuel cannot be stored in the same DSC. The following assumptions are employed in the criticality evaluation for failed FA debris in the EOS-37PTH DSC: No credit is taken for FFC or any secondary containers. A total of four failed fuel locations is considered; remaining locations are modeled with intact fuel, see Figure 7-25. A range of pellet diameters (0.6 to 1.0 inches) and array sizes (8x8, 9x9, 10x10) is considered until the peak reactivity is identified.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-16 EOS-89BTH Only Only one section of height (12 in.) equal to one egg-crate section of the basket is modeled with periodic boundary conditions at the axial boundaries (top and bottom) and reflective boundary conditions at the radial boundaries (sides) to represent infinite long FAs an infinite arrays of package. From a criticality standpoint, modeling a repetitive egg-crate section with periodic axial boundary

conditions or a full active fuel length with periodic axial boundary conditions (EOS-37PTH) that results in an infinite axial length are not different. For intact fuel, the pins are modeled assuming the maximum lattice average enrichment uniformily everywhere in the lattice. Natural uranium blankets, gadolinia, integral fuel burnable absorber (IFBA), erbia, or any other burnable absorber rods and axial or radial enrichment zones are modeled as uranium with the maximum lattice average enrichment. Water density is at optimum internal and external moderator density. It is assumed that the fuel rod outer diameter varies by inch for this evaluation.

7.4.1.4 Determination of keff The Monte Carlo calculations performed with CSAS5 (KENO V.a) use a flat neutron starting distribution. The total number of histories traced for each calculation is at least 800,000. This minimum number of histories is sufficient to achieve source convergence and produce standard deviations of less than 0.0010. The maximum keff for the calculation is determined with the following formula:

keff = k keno + 2keno All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-17 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-24 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-26 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-27 E. Determination of the Maximum Failed Initial Enrichment for Each Assembly Class A maximum of eight damaged fuels or four failed fuels balanced with intact fuels can be accommodated in the EOS-37PTH DSC, as shown in Figures 1F and 1H of the Technical Specifications

[7-8]. For criticality analyses, a single and conservative loading plan is considered to cover both damaged and failed FA loadings, as shown in the KENO model plot Figure 7-24. The most reactive configuration determined in Section 7.4.2.D.3 is considered for the 12 failed FAs in the loading. Failed fuel debris is addressed separately in Section 7.4.2.F.

The maximum allowable planar average initial enrichment of failed FAs balanced with intact FAs, for each FA class, as a function of basket assembly type (poison plate loading) and soluble boron concentration is documented in Table 7-51 with and without CCs. The maximum allowable enrichment determined for the loading of 37 intact FAs in Section 7.4.2.C applies to the intact FAs when determining the maximum allowable enrichments for the failed FAs in the loading plan shown in Figure 7-24. The failed design basis KENO model is used for each FA class evaluation. No credit is taken for burnup. The internal moderator density between 50% and 100% is varied to determine the peak reactivity for the specific configuration.

The EOS-37PTH DSC/EOS-TC model for this evaluation differs from the actual design and loadings as shown in the Technical Specification Figure 1F and Figure 1H [7-8] in the following ways: The B-10 content is at the minimum required for reactivity control for each basket assembly type, Failed FAs are loaded in 12 fuel compartments, The neutron shield and the neutron shield jacket (outer skin) of the EOS-TC are conservatively removed and EOS-TC pushed together with fresh water between the casks, The dimensions with limiting fabrication tolerances, as determined by the evaluations described in this section, are modeled. Two different fixed poison loadings (Basket Types A and B) are analyzed in the criticality calculations as listed in Table 7-1. The soluble boron concentration is varied from 2000 ppm to 2500 ppm (2600 ppm for the BW 15x15 FA class). The maximum analyzed initial enrichment is 5.0 wt. % U-235.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-29 As the failed FA configuration bounds the various damaged FA configurations, the maximum allowable planar average initial enrichments determined above are applicable for the loading of up to four failed FAs balanced with intact FAs, or for the loading of up to eight damaged FAs balanced with intact FAs. In addition, considering the conservatisms that have been used to create the failed design basis KENO model (i.e., guide tube locations filled with fuel rods or de-cladded fuel rods), damaged or failed FAs can be loaded either with or without CCs.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-30 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-31 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-36 H. Determination of the Maximum Initial Enrichment for BWR Fuel Assemblies The design basis KENO model with the GNF-2 fuel assembly design is employed to determine the maximum allowable initial enrichment for the three allowable fixed poison loadings. The KENO model employed herein incorporates the bounding modeling features evaluated in the previous evaluations and also is consistent with the actual design dimensions as discussed in the Section 7.3.1.

The results of the criticality analyses are shown in Table 7-43. These results demonstrate that the maximum keff of the system remains below that USL with a maximum enrichment of 4.80 wt. % U-235. As described in the MRF analyses, separate enrichment limits are determined for the ABB-10-C type BWR fuel assemblies and also shown in Table 7-43. These results indicate that the maximum allowable enrichment is reduced by 0.25 wt. %

U-235 for the Type M1-A and Type M1-B poison loading and by 0.20 wt. % U-235 for the Type M2-A poison loading compared to that for the GNF-2 fuel assembly.

7.4.4 Criticality

Results In Table 7-44, a summary of the bounding scenarios that exist for both the

EOS-37PTH and EOS-89BTH are presented. These are: dry storage condition, applicable to the DSC and placed in the EOS-HSM, normal loading or unloading operation where the DSC is in the fuel pool with 100% internal moderator density, and condition where the internal moderator density is at the optimum calculated for maximum reactivity.

For the EOS-37PTH , loading of intact fuels only, the most reactive case for the normal loading or unloading condition is calculated for the CE 15x15 class FA with 4.75 wt. % U-235, Type B basket, without CCs and 2000 ppm of soluble boron 100% internal moderator density, which is also the most optimum density. For the dry storage condition, this CE 15x15 case is modified by changing the internal and external moderator density to air, because this results in a bounding dry condition scenario.

For the EOS-37PTH, loading of damaged or failed fuels balanced with intact fuels, the most reactive case for the normal loading or unloading condition is calculated for the WE 17x17 class FA with 4.85 wt. % U-235 for intact fuels and 4.85 wt. % U-235 for failed fuels, (Basket Type B, without CCs and 2300 ppm of soluble boron 90% internal moderator density).

For the EOS-89BTH the most reactive case for the normal loading or unloading condition is calculated for the GNF2 FA with 4.80 wt. % U-235, Type M2-A basket and 100% internal moderator density, which is also the optimum density. For the dry storage condition, this GNF2 case is modified by changing the internal and external moderator density to air as this results in a bounding dry condition scenario.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-37 The criterion for subcriticality is that: k keno + 2keno < USL where USL is the upper subcriticality limit established by an analysis of benchmark criticality experiments. From Section 7.5 the USL for the EOS-37PTH DSC is 0.9404 while the USL for the EOS-89BTH DSC is 0.9418. From Table 7-44, the most reactive case determined for PWR intact fuel storage only is: k keno + 2keno = 0.9371+2*0.0007=0.9385 < 0.9404, From Table 7-44, the most reactive case determined for the storage of a maximum of up to eight damaged PWR FAs or up to four FFCs containing failed PWR fuel balanced with intact PWR FAs:

k keno + 2 keno = 0.9370+2*0.0007=0.9384 < 0.9404, From Table 7-44, the most reactive case determined for BWR fuel storage is:

k keno + 2keno = 0.9382+2*0.0008=0.9398 < 0.9418.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-105 Table 7-43 Determination of Minimum Poison Loading Requirement Basket Type Enrichment (wt% of U-235)

B-10 Content (mg/cm 2) kkeno keno k eff All Fuel Except ABB-10-C MMC 4.1 29.4 0.9343 0.0008 0.9359 4.45 37.2 0.9369 0.0009 0.9387 BORAL 4.8 45.0 0.9382 0.0008 0.9398 ABB-10-C Fuel MMC 3.85 29.4 0.9271 0.0008 0.9287 4.25 37.2 0.9329 0.0009 0.9347 BORAL 4.55 45.0 0.9347 0.0008 0.9363 Table 7-44 Criticality Results EOS-37PTH: Regulatory Requirements for Storage Configuration k keno keno k eff Dry Storage (Bounded by infinite array of undamaged storage casks) for intact fuel assemblies 0.6203 0.0003 0.6209 Normal Loading and Unloading Conditions (Optimum Moderator Density) for intact fuel assemblies 0.9371 0.0007 0.9385 Normal Loading and Unloading Conditions (Optimum Moderator Density) for damaged and failed fuels balanced with intact fuels 0.9370 0.0007 0.9384 USL = 0.9404 EOS-89BTH: Regulatory Requirements for Storage Configuration k keno keno k eff Dry Storage (Bounded by infinite array of undamaged storage casks) 0.5187 0.0003 0.5193 Normal Loading and Unloading Conditions (Optimum Moderator Density) 0.9382 0.0008 0.9398 USL = 0.9418 The change on this page is related to Enclosure 3 changes not associated with any RSI, Change 3.

NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-146 Table 7-80 EOS-37PTH - Failed Fuel Debris Sensitivity Evaluation - BW 15x15 Assembly Class (4 Pages) Case Description kkeno keno k eff Array size: 10x10, Fissile Rods Diameter= 0.8 inch Pitch =2.1 inches, IMD 80 % 0.9268 0.0008 0.9284 Pitch =2.2 inches, IMD 90 % 0.9296 0.0007 0.9309 Pitch =2.2250 inches, IMD 70 % 0.9183 0.0008 0.9199 Pitch =2.2250 inches, IMD 80 % 0.9273 0.0007 0.9287 Pitch =2.2250 inches, IMD 90 % 0.9306 0.0007 0.9319 Pitch =2.2250 inches, IMD 100 % 0.9298 0.0008 0.9313 Pitch =2.2250 inches, IMD 90 %, 1 missing rod 0.9298 0.0007 0.9312 Pitch =2.2250 inches, IMD 90 %, 2 missing rods 0.9312 0.0006 0.9325 Pitch =2.2250 inches, IMD 90 %, 4 missing rods 0.9312 0.0007 0.9325 Pitch =2.2250 inches, IMD 90 %, 6 missing rods 0.9297 0.0007 0.9310 Array size: 10x10, Fissile Rods Diameter= 0.70 inch Pitch =2 inches, IMD 90 % 0.9257 0.0007 0.9272 Pitch =2.15 inches, IMD 90 % 0.9301 0.0009 0.9318 Pitch =2.2 inches, IMD 70 % 0.9200 0.0007 0.9214 Pitch =2.2 inches, IMD 80 % 0.9280 0.0007 0.9294 Pitch =2.2 inches, IMD 90 % 0.9317 0.0007 0.9331 Pitch =2.2 inches, IMD 100 % 0.9304 0.0008 0.9319 Pitch =2.2250 inches, IMD 90 % 0.9305 0.0007 0.9319 Pitch =2.2 inches, IMD 100 %, 1 missing rod 0.9312 0.0008 0.9327 Pitch =2.2 inches, IMD 100 %, 2 missing rods 0.9315 0.0007 0.9328 Pitch =2.2 inches, IMD 90 %, 4 missing rods 0.9305 0.0007 0.9319 Pitch =2.2 inches, IMD 90 %, 6 missing rods 0.9286 0.0007 0.9300 Array size: 10x10, Fissile Rods Diameter= 0.60 inch Pitch =2.0 inches, IMD 90 % 0.9268 0.0008 0.9284 Pitch =2.15 inches, IMD 90 % 0.9290 0.0007 0.9304 Pitch =2.2 inches, IMD 70 % 0.9201 0.0007 0.9215 Pitch =2.2 inches, IMD 80 % 0.9287 0.0007 0.9302 Pitch =2.2 inches, IMD 90 % 0.9299 0.0009 0.9316 Pitch =2.2 inches, IMD 100 % 0.9283 0.0007 0.9296 Pitch =2.2250 inches, IMD 90 % 0.9295 0.0007 0.9309 Pitch =2.2 inches, IMD 90 %, 1 missing rod 0.9295 0.0007 0.9309 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-147 Table 7-80 EOS-37PTH - Failed Fuel Debris Sensitivity Evaluation - BW 15x15 Assembly Class (4 Pages) Case Description kkeno keno k eff Pitch =2.2 inches, IMD 90 %, 2 missing rods 0.9288 0.0007 0.9302 Pitch =2.2 inches, IMD 90 %, 3 missing rods 0.9263 0.0007 0.9278 Pitch =2.2 inches, IMD 90 %, 4 missing rods 0.9262 0.0010 0.9282 Array size: 9x9, Fissile Rods Diameter= 0.9 inch Pitch =2.3 inches, IMD 100 % 0.9270 0.0007 0.9284 Pitch =2.4 inches, IMD 90 % 0.9284 0.0007 0.9298 Pitch =2.4722 inches, IMD 70 % 0.9189 0.0008 0.9204 Pitch =2.4722 inches, IMD 80 % 0.9268 0.0007 0.9281 Pitch =2.4722 inches, IMD 90 % 0.9306 0.0006 0.9318 Pitch =2.4722 inches, IMD 100 % 0.9279 0.0006 0.9292 Pitch =2.4722 inches, IMD 90 %, 1 missing rod 0.9305 0.0007 0.9319 Pitch =2.4722 inches, IMD 90 %, 2 missing rods 0.9292 0.0007 0.9306 Pitch =2.4722 inches, IMD 90 %, 3 missing rods 0.9299 0.0008 0.9314 Pitch =2.4722 inches, IMD 90 %, 4 missing rods 0.9286 0.0008 0.9301 Array size: 9x9, Fissile Rods Diameter= 0.75 inch Pitch =2.1 inches, IMD 90 % 0.9256 0.0007 0.9271 Pitch =2.3 inches, IMD 90 % 0.9298 0.0008 0.9314 Pitch =2.4 inches, IMD 90 % 0.9303 0.0007 0.9316 Pitch =2.4722 inches, IMD 70 % 0.9211 0.0008 0.9226 Pitch =2.4722 inches, IMD 80 % 0.9278 0.0007 0.9292 Pitch =2.4722 inches, IMD 90 % 0.9309 0.0007 0.9323 Pitch =2.4722 inches, IMD 100 % 0.9326 0.0009 0.9343 Pitch =2.4722 inches, IMD 90 %, 1 missing rod 0.9305 0.0008 0.9320 Pitch =2.4722 inches, IMD 90 %, 2 missing rods 0.9302 0.0007 0.9315 Pitch =2.4722 inches, IMD 90 %, 3 missing rods 0.9307 0.0007 0.9321 Pitch =2.4722 inches, IMD 90 %, 4 missing rods 0.9291 0.0008 0.9306 Array size: 9x9, Fissile Rods Diameter= 0.65 inch Pitch =2.1 inches, IMD 90 % 0.9255 0.0007 0.9270 Pitch =2.3 inches, IMD 90 % 0.9268 0.0007 0.9281 Pitch =2.4 inches, IMD 90 % 0.9283 0.0007 0.9296 Pitch =2.4722 inches, IMD 70 % 0.9167 0.0008 0.9183 Pitch =2.4722 inches, IMD 80 % 0.9260 0.0008 0.9277 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-148 Table 7-80 EOS-37PTH - Failed Fuel Debris Sensitivity Evaluation - BW 15x15 Assembly Class (4 Pages) Case Description kkeno keno k eff Pitch =2.4722 inches, IMD 90 % 0.9294 0.0007 0.9307 Pitch =2.4722 inches, IMD 100 % 0.9277 0.0007 0.9292 Pitch =2.4722 inches, IMD 90 %, 1 missing rod 0.9275 0.0007 0.9288 Pitch =2.4722 inches, IMD 90 %, 2 missing rods 0.9284 0.0007 0.9297 Pitch =2.4722 inches, IMD 90 %, 3 missing rods 0.9261 0.0007 0.9276 Pitch =2.4722 inches, IMD 90 %, 4 missing rods 0.9267 0.0007 0.9282 Array size: 8x8, Fissile Rods Diameter= 1 inch Pitch =2.6 inches, IMD 90 % 0.9272 0.0007 0.9286 Pitch =2.7 inches, IMD 90 % 0.9300 0.0007 0.9314 Pitch =2.7813 inches, IMD 70 % 0.9189 0.0007 0.9202 Pitch =2.7813 inches, IMD 80 % 0.9266 0.0007 0.9280 Pitch =2.7813 inches, IMD 90 % 0.9306 0.0007 0.9321 Pitch =2.7813 inches, IMD 100 % 0.9307 0.0007 0.9321 Pitch =2.7813 inches, IMD 90 %, 1 missing rod 0.9305 0.0007 0.9320 Pitch =2.7813 inches, IMD 90 %, 2 missing rods 0.9288 0.0007 0.9303 Pitch =2.7813 inches, IMD 90 %, 3 missing rods 0.9295 0.0007 0.9309 Pitch =2.7813 inches, IMD 100 %, 4 missing rods 0.9277 0.0008 0.9293 Array size: 8x8, Fissile Rods Diameter= 0.9 inch Pitch =2.4 inches, IMD 90 % 0.9265 0.0008 0.9280 Pitch =2.6 inches, IMD 90 % 0.9279 0.0007 0.9292 Pitch =2.7 inches, IMD 90 % 0.9299 0.0008 0.9315 Pitch =2.7813 inches, IMD 70 % 0.9204 0.0007 0.9217 Pitch =2.7813 inches, IMD 80 % 0.9303 0.0007 0.9318 Pitch =2.7813 inches, IMD 90 % 0.9305 0.0007 0.9319 Pitch =2.7813 inches, IMD 100 % 0.9300 0.0007 0.9313 Pitch =2.7813 inches, IMD 90 %, 1 missing rod 0.9324 0.0007 0.9338 Pitch =2.7813 inches, IMD 90 %, 2 missing rods 0.9297 0.0008 0.9313 Pitch =2.7813 inches, IMD 90 %, 3 missing rods 0.9299 0.0007 0.9313 Pitch =2.7813 inches, IMD 90 %, 4 missing rods 0.9296 0.0008 0.9312 Array size: 8x8, Fissile Rods Diameter= 0.75 inch Pitch =2.4 inches, IMD 90 % 0.9243 0.0007 0.9257 Pitch =2.6 inches, IMD 90 % 0.9273 0.0007 0.9286 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-149 Table 7-80 EOS-37PTH - Failed Fuel Debris Sensitivity Evaluation - BW 15x15 Assembly Class (4 Pages) Case Description kkeno keno k eff Pitch =2.7 inches, IMD 90 % 0.9283 0.0006 0.9295 Pitch =2.7813 inches, IMD 70 % 0.9196 0.0007 0.9209 Pitch =2.7813 inches, IMD 80 % 0.9253 0.0008 0.9268 Pitch =2.7813 inches, IMD 90 % 0.9283 0.0007 0.9296 Pitch =2.7813 inches, IMD 100 % 0.9273 0.0007 0.9288 Pitch =2.7813 inches, IMD 90 %, 1 missing rod 0.9283 0.0007 0.9296 Pitch =2.7813 inches, IMD 90 %, 2 missing rods 0.9268 0.0007 0.9282 Pitch =2.7813 inches, IMD 90 %, 3 missing rods 0.9264 0.0010 0.9284 Pitch =2.7813 inches, IMD 90 %, 4 missing rods 0.9262 0.0007 0.9276 All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-150 Table 7-81 EOS-37PTH - Maximum Uranium Mass per FFC, Failed Fuel Debris Analysis Fissile Rods Diameter Maximum Uranium Mass 10x10 array size 0.8 inch 1104 kg 0.6 inch 621 kg 9x9 array size 0.9 inch 1132 kg 0.6 inch 503kg 8x8 array size 1 inch 1104 kg 0.6 inch 397 kg Note: This table presents the as-modeled uranium masses in the failed fuel debris models. The MTU limits for an FFC containing failed fuel are defined in Chapter 2, Table 2-4b.

All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-176 Figure 7-25 Criticality Analysis Model for Failed Fuel Debris Loading in the EOS-37PTH DSC All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 7-177 Figure 7-26 Keff Variation for Failed Fuel Assembly Debris Models All Indicated Changes are in response to Crit-Shield 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 9-4 Note: Verify that a TC spacer of appropriate height is placed inside the TC to provide the correct airflow and interface at the top of the TC during

loading, drying, and sealing operations for DSCs that are shorter than the

TC cavity length.

6. Verify specified lubrication of the TC rails.

7. Examine the DSC for any physical damage that might have occurred since the receipt inspection was performed. The DSC is to be cleaned and any loose debris removed. 8. Record the DSC serial number that is located on the grapple ring. Verify the DSC type and basket type against the DSC serial number. Verify that the DSC is appropriate for the specific fuel loading campaign per the criteria specified in

Section 2.1 (EOS-37PTH DSC) or Section 2.2 (EOS-89BTH DSC) of the

Technical Specifications [9-5].

9. Using a crane, lower the DSC into the TC cavity by the internal lifting lugs and rotate the DSC to match the TC and DSC alignment marks. 9a. If damaged FAs or loaded failed fuel canisters (FFCs) are included in a specific loading campaign, verify that the appropriate basket type is used and place the required number of bottom end caps provided for damaged fuel or FFCs into the cell locations per Technical Specification 2.1. Optionally, this step may be performed at any prior time. 9b. Verify that the bottom fuel assembly spacers, if required, are present in the fuel cells. Optionally, this step may be performed at any prior time.

10. Fill the TC/DSC annulus with clean water. Place the inflatable seal into the upper TC liner recess and seal the TC\DSC annulus by pressurizing the seal with compressed air. Note: A TC/DSC annulus pressurization tank filled with clean water is connected to the top vent port of the TC via a hose to provide a positive head above the level of water in the TC/DSC annulus. This is an optional arrangement, which provides additional assurance that contaminated water from the fuel pool will not enter the TC/DSC annulus, provided a positive head is maintained at all times.

11. Fill the DSC cavity with water from the fuel pool or an equivalent source that meets the requirements of Section 3.2.1 of the Technical Specifications [9-5] for

boron concentration, if applicable.

12. Place the top shield plug onto the DSC. Examine the top shield plug to ensure a proper fit. Optionally, the top shield plug, once fitted, may be removed and disconnected from the yoke. It may be installed later, once the DSC is loaded and prior to removing it from the pool.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 9-6 the loading plan. All fuel movements from any rack location are performed under strict compliance of the fuel movement schedule.

- If loading damaged/failed fuel, verify that the required number of bottom end caps for damaged fuel or FFCs for failed fuel are installed in appropriate fuel compartment tube locations before fuel load.

6. Prior to loading of a FA and CC, if applicable, into the DSC, the identity of the assembly and CC, if applicable, is to be verified by two individuals using an underwater video camera or other means. Verification of CC identification is optional if the CC has not been moved from the host FA since its last verification.

Read and record the identification number from the FA and CCs, if applicable, and check this identification number against the DSC loading plan, which indicates which FAs and CCs, if applicable, are acceptable for dry storage.

7. Position the FA for insertion into the selected DSC storage cell and load the FA. Repeat Steps 6 and 7 for each FA loaded into the DSC. After the DSC has been fully loaded, check and record the identity and location of each FA and CCs, if applicable, in the DSC.

If loading damaged FAs, place top end caps over each damaged FA placed into the basket. If loading failed fuel, place top end caps over each FFC placed into the basket.

8. After all the FAs and CCs, if applicable, have been placed into the DSC and their identities verified, position the lifting yoke and the top shield plug and lower the

shield plug onto the DSC. CAUTION: Verify that all the lifting height restrictions as a function of temperature specified in Section 5.2.1 of the Technical Specifications [9-5] can be met in the following steps that involve lifting of the TC.

9. Visually verify that the top shield plug is properly seated onto the DSC.

10. Position the lifting yoke with the TC trunnions and verify that it is properly engaged. 11. Raise the TC to the pool surface. Prior to raising the top of the TC above the water surface, stop vertical movement.

12. Inspect the top shield plug to verify that it is properly seated onto the DSC. If not, lower the TC and reposition the top shield plug. Repeat Steps 8 to 12 as necessary.

13. Continue to raise the TC from the pool and spray the exposed portion of the TC with clean water until the top region of the TC is accessible.

14. Disengage the rigging cables from the top shield plug and remove the eyebolts.

15. Drain any excess water from the top of the DSC shield plug back to the fuel pool.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 9-17

10. Operate the ram grapple and engage the grapple arms with the DSC grapple ring.

11. Recheck all alignment marks and ready all systems for DSC transfer. CAUTION: The time limits for the unloading of the DSC should be determined using the heat loads at the time of the unloading operation and the methodology presented in Sections 4.5 and 4.6 before pulling the DSC out of the

EOS-HSM. 12. Activate the ram to pull the DSC into the transfer TC.

13. Disengage the ram grapple mechanism so that the grapple is retracted away from the DSC grapple ring.

14. Retract and disengage the ram system from the TC and move it clear of the TC. Remove the TC restraints from the EOS-HSM. 15. Using the skid positioning system, disengage the TC from the EOS-HSM access opening. 16. Bolt the TC cover plate into place, tightening the bolts to the required torque in a star pattern.

17. Retract the vertical jacks and disconnect the skid positioning system.

18. Ready the trailer for transfer.

19. Replace the EOS-HSM door and DSC axial restraint on the EOS-HSM. 9.2.2 Removal of Fuel from the DSC Note that the EOS-37PTH DSC will provide the retrievability function for damaged and FFCs per ISG-2, Revision 2. However, if it is necessary to remove fuel from the DSC, intact and damaged fuel can be removed in a dry transfer facility or the initial fuel loading sequence can be reversed and the plant's spent fuel pool utilized. Procedures for wet unloading of the DSC are presented here. Dry unloading procedures are essentially identical up to the removal of the DSC vent plug and drain

port cover. CAUTION: Monitor the applicable time limits determined for the unloading operation in Step 11, Section 9.2.1 above , or Step 16 of Section A.9.2.1, until the TC/DSC Annulus is filled with water in Step 12 of Section 9.2.2. If the time limits for unloading cannot be met, initiate forced cooling.

1. Transfer the loaded TC from the ISFSI to inside the plant's fuel or reactor building along the designated transfer route.

All Indicated Changes are in response to Materials 1 NUHOMS EOS System Updated Final Safety Analysis Report Rev. 1, 01/18 August 2018 Revision 2 72-1042 Amendment 1 Page 9-20

25. Position the TC lifting yoke and engage the TC lifting trunnions, install eyebolts or other lifting attachment(s) into the shield plug, and connect the rigging cables to the eyebolts/lifting attachment(s).

26. Move the scaffolding away from the TC as necessary.

27. Lift the TC just far enough to allow the weight of the TC to be distributed onto the yoke lifting arms. Verify that the lifting arms are properly positioned on the

trunnions.

28. Optionally, secure a sheet of suitable material to the bottom of the TC to minimize the potential for ground-in contamination. This may also be done prior to initial placement of the TC in the designated area.

29. Prior to the TC being lifted into the fuel pool, the water level in the pool should be adjusted as necessary to accommodate the TC/DSC volume, as necessary.

30. Position the TC over the TC loading area in the spent fuel pool.

31. Lower the TC into the pool. As the transfer TC is being lowered, the exterior surface of the TC should be sprayed with clean water.

32. Lower the TC into the fuel pool leaving the top surface of the TC above the surface of the pool water. Verify correct connections of the annulus seal and

annulus/neutron shield tank, if used.

33. Disengage the lifting yoke from the TC and lift the shield plug from the DSC.

34. Remove the fuel from the DSC. Note: Special attention should be given to unloading the FAs (especially for boiling water reactor (BWR fuel) to wait until any loose particles have settled and slowly move the FAs to minimize fuel crud dispersion in the

spent fuel pool. The dry TC reflood process, during unloading of BWR fuel, has the potential to disperse crud into the pool and become airborne, creating airborne exposure and personnel contamination hazards. If the DSC contains damaged fuel: a. remove the top end caps. b. remove the fuel using the standard fuel handling procedures.

If the DSC contains failed fuel: a. remove the FFC top lid. b. lift and remove the FFC from the DSC.

All Indicated Changes are in response to Materials 1

v t e Letter Sequence Other
EPID:L-2018-LLA-0043, Package: Acceptance Review of Tn Americas LLC Application for Certificate of Compliance No. 1042, Amendment No. 1 to Nuhoms Eos System (Docket No. 72-1042, CAC No. 001028, EPID: L-2018-LLA-0043) - Request for Supplemental Information (Approved, Closed)
Initiation Request, Request, Request, Request, Request, Request Acceptance, Acceptance, Acceptance, Acceptance, Acceptance Supplement Administration Questions 21 December 2018 21 December 2018 14 January 2019 29 January 2019 29 January 2019 3 May 2019 23 May 2019 12 June 2019 Answers Results Approval Other: ML18144A087, ML18255A093, ML18255A094, ML18255A096, ML18255A097, ML18255A098, ML18255A101, ML18255A102, ML19177A014, ML20136A049, ML20136A050, ML20136A051
MONTHYEAR2019-01-14 [Table View]

ML18255A101