ML23348A306
| ML23348A306 | |
| Person / Time | |
|---|---|
| Site: | HI-STORM 100 |
| Issue date: | 12/14/2023 |
| From: | Holtec |
| To: | Office of Nuclear Material Safety and Safeguards |
| Shared Package | |
| ML23348A301 | List: |
| References | |
| 5021073, CoC No. 1040 | |
| Download: ML23348A306 (1) | |
Text
Attachment 4 to Holtec Letter 5021073
1.1 INTRODUCTION
HI-STORM UMAX is a dry, in-ground spent fuel storage system consisting of any number of Vertical Ventilated Modules (VVM) each containing one canister. The HI-STORM UMAX is designed to be fully compatible with all HI-TRAC transfer casks and multi-purpose canisters (MPC) presently certified under USNRC Docket No. 72-1014 and 72-1032. Safety analyses documented herein treat all MPCs listed in Table 1.2.1. However, as would be expected, the largest canisters, i.e., those licensed in the HI-STORM FW docket are governing in terms of structural and thermal margins. These largest canisters, namely MPC-37 and MPC-89 are termed Licensing Basis MPCs and the certification request for storage in HI-STORM UMAX is limited to these MPCs only. For completeness, the permissible contents from the HI-STORM FW docket are excerpted in Chapter 2 herein and also reproduced in the Technical Specification applicable to the CoC. The safety analyses summarized in this FSAR are intended to demonstrate that the HI-STORM UMAX System can safely store PWR or BWR fuel assemblies, in the MPC-37 or MPC-89, respectively. The MPC is identified by the maximum number of fuel assemblies it can contain in the fuel basket. As presently licensed in the HI-STORM FW docket, the standard MPC external diameters are identical to allow the use of a single overpack design; however the height of the MPC is varied to accord with the SNF to be loaded.
The HI-STORM UMAX Version B VVM is a variant of the HI-STORM UMAX design with its own licensing drawing listed in Section 1.5. Version B utilizes an enhanced HI-STORM UMAX closure lid design and includes optional seismic restraint features, for use if needed to meet structural requirements for design-basis site earthquakes. The optional seismic restraint features are referred to as MSE (Most Severe Earthquake) features. The HI-STORM UMAX Version B accepts the same MPCs and fuel types as the standard HI-STORM UMAX and the basic structural, shielding, and thermal-hydraulic characteristics remain unchanged. Hereafter in this FSAR, reference to HI-STORM UMAX is construed to also apply to the HI-STORM UMAX Version B variant. Where necessary, the text distinguishes among the different overpack designs.
The HI-STORM UMAX Version B1 and Version B2 are variants of the HI-STORM UMAX design with their own licensing drawing listed in Section 1.5. Version B1 and Version B2 are similar to Version B, with the vent sizes being the only difference between them. Version B1 and Version B2 utilize thermally qualified different heat loads which can be found in Chapter 2.
Similar to Version B, Version B1 and Version B2 both include optional seismic restraint features referred to as MSE (Most Severe Earthquake) features. Version B1 and B2 accept MPC-37 and MPC-37 Type 1 for the MPC type, as well as 16x16 A for the fuel type. Hereafter in this FSAR, reference to HI-STORM UMAX is construed to also apply to the HI-STORM UMAX Version B1 and B2 variants.
The MPC is an integrally welded pressure vessel designed to meet the stress limits of the ASME Boiler and Pressure Vessel Code,Section III, Subsection NB [1.1.1]. The MPC defines the Confinement Boundary for the stored spent nuclear fuel assemblies. Regardless of the storage cell count, the construction of the MPC is fundamentally the same; the basket is a honeycomb structure comprised of cellular elements. This is positioned within a circumscribing cylindrical canister shell. The egg-crate construction and cell-to-canister shell interface employed in the MPC basket impart the structural stiffness necessary to satisfy the limiting load conditions HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 1-9 to Holtec Letter 5021073 1.5 FIGURES AND DRAWINGS The licensing drawing for the HI-STORM UMAX System, pursuant to the requirements of 10CFR72.24(c)(3), is provided in this section. The material list on the licensing drawing contains sufficient information to articulate major design features and general operational characteristics of UMAX. Further, it is intended to serve as the control information to guide the preparation of the documents required to manufacture the components under Holtecs Quality Assurance Program. Holtecs Quality Assurance Program requires that the entire array of manufacturing documents must remain in complete conformance with the Licensing Drawing Package at all times.
The MPC and HI-TRAC drawings listed below are excerpted from the HI-STORM FW docket.
Drawing Package Description Revision Number 8446 HI-STORM UMAX Canister 22 Storage System 10017 HI-STORM UMAX Version Proposed Rev 7 B Canister Storage System 6514 HI-TRAC VW - MPC-37 15 6799 HI-TRAC VW - MPC-89 11 6505 MPC-37 ENCLOSURE 29 VESSEL 6506 MPC-37 FUEL BASKET 16 6512 MPC-89 ENCLOSURE 31 VESSEL 6507 MPC-89 FUEL BASKET 16
[PROPRIETARY DRAWINGS WITHHELD IN ACCODRDANCE WITH 10 CFR 2.390]
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 1-39 to Holtec Letter 5021073 Table 3.1.13 KEY INPUT DATA FOR FINITE ELEMENT MODEL OF HI-STORM UMAX VVM Item Value Overall height of HI-STORM UMAX VVM
[PROPRIETARY INFORMATION WITHHELD IN (including Closure lid) from bottom of SFP to ACCORDANCE WITH 10 CFR 2.390]
top of ISFSI pad Height of CEC shell cavity including the top [PROPRIETARY INFORMATION WITHHELD IN surface of the flange ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Height of top lid above top of grade ACCORDANCE WITH 10 CFR 2.390]
Inside diameter of HI-STORM UMAX storage [PROPRIETARY INFORMATION WITHHELD IN cavity (CEC shell) (See Note 1) ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Outside diameter of Closure Lid ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN CEC shell thickness ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Thickness of CEC flange ACCORDANCE WITH 10 CFR 2.390]
Lifting rib (in the Closure Lid outlet pipe) [PROPRIETARY INFORMATION WITHHELD IN thickness ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN CEC Baseplate thickness ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Material of construction ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Ref. temperature for material properties ACCORDANCE WITH 10 CFR 2.390]
[PROPRIETARY INFORMATION WITHHELD IN Concrete density(reference) ACCORDANCE WITH 10 CFR 2.390]
Notes
- 1. UMAX System may have an MPC with increased shell thickness with corresponding increased MPC outside diameter and UMAX storage cavity inside diameter. Such systems are equivalent to or bounded by the existing structural analysis for the UMAX VVM listed in this table.
The ISFSI Pad may have a dry density of 135 lb/ft,3 and the SFP may have a dry density of 120 lb/ft3; however, using 150 lb/ft3 as a reference dry density for all of the concrete is conservative.
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 3-29 to Holtec Letter 5021073 Table 3.4.9 BOUNDING STRESS AND BUCKLING ANALYSIS RESULTS OF THE SHELL DURING MPC TRANSFER OPERATION Calculated Value Allowable Limit Item Safety Factor ksi ksi Compressive Stress of Compression: 156.87 9.38 1.698 CEC Shell Buckling: 239.752.4 141.28.7 HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 3-77 to Holtec Letter 5021073 CHAPTER 4: THERMAL EVALUATION 4.0 OVERVIEW HI-STORM UMAX is an underground vertical ventilated module (VVM) with openings for air ingress and egress and internal air flow passages for ventilation cooling of loaded MPC. The licensing drawing package for the HI-STORM UMAX is provided in Section 1.5. Thermal design requirements are presented in Section 2.5. The analyses summarized in this chapter focus on the governing canisters out of the population of MPCs listed in Table 1.2.1. This chapter, however, supports the certification of only MPC-37 and MPC-89 at this time. The analyses reported for smaller canisters are for reference purposes only.
Section 1.2 provides a summary description of the HI-STORM UMAX system. The MPC types considered for evaluating storage in HI-STORM UMAX VVMs are listed in Table 1.2.1. In this chapter, compliance of HI-STORM UMAX systems thermal performance to 10CFR72 requirements for storage at an ISFSI using 3-D thermal simulation models is established. The analyses consider passive rejection of decay heat from the stored SNF assemblies to the environment under normal, off-normal, and accident conditions of storage. In particular, the thermal margins of safety for long-term storage of both moderate burnup (up to 45,000 MWD/MTU) and high burnup spent nuclear fuel (greater than 45,000 MWD/MTU) in the HI-STORM UMAX system are quantified. The HI-STORM UMAX deploys MPCs and HI-TRAC transfer casks that have been previously certified in HI-STORM FW FSAR and CoC (USNRC Docket 72-1032). Safe thermal performance during fuel loading, unloading and on-site transfer operations, collectively referred to as short-term operations utilizing the HI-TRAC VW transfer cask for MPC-37 and MPC-89 is also evaluated. The cases of normal, off-normal and accident conditions of storage, enumerated in Chapter 2 are also evaluated for the MPC designs in Table 1.2.1 to establish an acceptable safety case for their long term storage in the HI-STORM UMAX VVMs.
As described in Chapter 1, two different versions of HI-STORM UMAX design are available -
standard and Version B. HI-STORM UMAX Version B further has two variants namely Version B1 and Version B2. Version B1 and Version B2 are similar to Version B with the inlet air vent sizes being the only difference between them. The design details of all the HI-STORM UMAX designs are shown in the licensing drawing package (Section 1.5). The design details are shown in the licensing drawing package (Section 1.5). Thermal evaluations of both design versions are performed to demonstrate safety in this chapter. Unless stated, thermal evaluations in this chapter are based on the standard HI-STORM UMAX design.
The thermal evaluation of HI-STORM UMAX follows the guidelines of NUREG-1536 [4.0.1] and ISG-11 [4.0.2]. These guidelines provide specific limits on the permissible maximum cladding temperature in the stored commercial spent fuel (CSF)
- and other Confinement Boundary components, and on the maximum permissible pressure in the confinement space under certain
- Defined as nuclear fuel that is used to produce energy in a commercial nuclear reactor (See Glossary).
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-1 to Holtec Letter 5021073 Rev 3 limits are satisfied with comfortable margins.
The maximum peak cladding temperature results for MPC-37, MPC-89 and MPC-32, reported in Table 4.1.2, show that MPC-37 with short fuel under Heat Load Chart 1 produces the highest PCT.
Therefore, MPC-37 with short fuel under Heat Load Chart 1 fulfills the criterion for designation as the governing thermal configuration. This governing thermal configuration is used to perform the thermal safety analyses that are reported in the subsequent sections in this chapter.
As described in Section 4.0, two different versions of HI-STORM UMAX design are available -
standard and Version B. All the above thermal evaluations to determine the governing MPC and heat load pattern are performed using the standard design. To determine the bounding version of the UMAX, the governing MPC and heat load pattern are adopted i.e. MPC-37 with the short fuel under Heat Load Chart 1. The maximum peak cladding temperature results are reported in Table 4.1.3 for both UMAX design versions. The results demonstrate that both UMAX designs versions produce the same PCT. HI-STORM UMAX Version B has two variants with different inlet air vent sizes. Thermal evaluations are performed explicitly for HI-STORM UMAX Version B1 and Version B2 containing MPC-37 and MPC-37 Type 1 with 16x16A fuel. The PCT for design variants Version B1 and Version B2 are bounded by the UMAX standard design as reported in Table 4.1.3.
In this FSAR, the standard design version is adopted to perform all the licensing basis calculations to establish safety for HI-STORM UMAX System.
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-6 to Holtec Letter 5021073 Table 4.1.3 PEAK CLADDING TEMPERATURE RESULTS FOR DIFFERENT HI-STORM UMAX DESIGN VERSIONS**
Temperature UMAX Versions oC (oF)
Standard 367 (693)*
Version B 367 (693)
Version B1 348 (659)
Version B2 289 (552)
Version B1 (with MPC-37 Type 1) 331 (628)***
- The PCT results tabulated herein are for normal storage condition of HI-STORM UMAX design versions under quiescent (no wind) conditions.
UMAX Standard and Version B designs are loaded with short MPC-37 under Heat Load Chart 1. UMAX Version B1 and Version B2 are loaded with MPC-37 and MPC-37 Type 1 containing 16x16A fuel under heat loads defined in Table 2.1.13, Table 2.1.13, Table 2.1.14 and Table 2.1.16.
- Standard version is adopted to perform all the licensing basis calculations for HI-STORM UMAX System in this safety report.
- The PCT result for Version B2 loaded with MPC-37 is bounded by Version B1, therefore, only Version B1 loaded with MPC-37 Type 1 is reported herein.
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-9 to Holtec Letter 5021073 4.4 THERMAL EVALUATION FOR NORMAL CONDITIONS OF STORAGE The HI-STORM UMAX System thermal evaluation is performed in accordance with the guidelines of NUREG-1536 [4.0.1] and ISG-11 [4.0.2]. Table 1.2.1 lists the canister types and their host dockets where their thermal qualifications are performed. The candidate canisters and the heat load charts are identified and summarized in Table 4.1.1. These candidate thermal configurations, as mentioned in Section 4.1, are analyzed using the FLUENT model described below to identify the governing thermal configuration, defined as the one that yields the highest PCT.
[
PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390
]
4.4.1 FLUENT Thermal Model The thermal analysis model for the HI-STORM UMAX system utilizes the MPC models for MPC-37 and MPC-89 described in reference [4.1.2] and that for MPC-32 described in [4.1.1]. The effective properties of the fuel storage cells used in the thermal analysis of MPC-37 and MPC-89 in the HI-STORM UMAX System are conservatively 10% lower than those reported in the HI-STORM FW FSAR [4.1.2]. A geometrically accurate 3D thermal model of the HI-STORM UMAX VVM is constructed in the manner of HI-STORM 100U in Docket number 72-1014 for analysis. The VVM closure lid, inlet and outlet duct, the inner and outer annulus, the U-turn and the air plenum above the MPC are explicitly modeled.
The airflow through the cooling passages of the VVM is modeled [PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390] recommended in the Holtec-proprietary benchmarking report [4.4.1]. This is the same modeling approach as used in docket numbers 72-1014 and 72-1032. The underside of the VVM Support Foundation Pad is assumed to be supported on a subgrade at an isothermal surface temperature (see Table 4.1.1). The VVM thermal models are constructed using the same modeling platform used for aboveground analysis (FLUENT version 6.3 or FLUENT version 18.1).
[
PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390
]
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-19 to Holtec Letter 5021073 4.4.4.2 Evaluation of HI-STORM UMAX Version B Design
[
PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390
]
4.4.5 Maximum Internal Pressure in the MPC The MPC is initially filled with dry helium after fuel loading and drying prior to installing the MPC closure ring. In the MPC host docket (72-1014), the different helium backfill pressure specifications are allowed according to the different CoC amendments. For each type of MPC in Docket 72-1014, the specification of helium backfill pressure for HI-STORM UMAX System envelop all allowed specifications defined in the MPC host docket. The helium backfill pressure for the MPCs authorized to be stored in HI-STORM UMAX are presented in Table 4.4.6.
To provide additional helium backfill range for less than design basis heat load, the following Sub-Design-Basis (SDB) heat load scenarios are allowed for MPC-37 and MPC-89:
(i) MPC-37 under 90% of Heat Load Chart 1 (see Table 4.4.3)
(ii) MPC-89 under 90% of Design Heat Load (see Table 4.4.4)
(iii) MPC-37 under threshold heat load (see Table 4.4.5)
(iv) MPC-89 under threshold heat load (see Table 4.4.5)
The storage cell and MPC heat load limits under the 90% of Design Heat Load scenarios mentioned above are obtained by multiplying 0.9 to the individual storage cell of design heat load, and HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-24 to Holtec Letter 5021073 4.6 OFF-NORMAL AND ACCIDENT EVENTS The safety evaluation of off-normal and accident conditions described in Section 2.5 is presented in this section. Thermal analysis of the HI-STORM UMAX System is performed for the governing thermal configuration, i.e. MPC-37 with short fuel under heat load Chart 1, identified by the analysis in Section 4.1.
4.6.1 Off-Normal Events 4.6.1.1 Off-Normal Environmental Temperature To evaluate the effect of off-normal weather conditions, an off-normal ambient temperature (Table 2.3.6) is postulated to persist for a sufficient duration to allow the HI-STORM UMAX system to reach steady state conditions. Because of the large mass of the HI-STORM UMAX system, with its corresponding large thermal inertia and the limited duration for the off-normal temperatures that arise in real life, this assumption is conservative. Starting from a baseline condition evaluated in Section 4.4 (normal ambient temperature and limiting fuel storage configuration) the temperatures of the HI-STORM UMAX system are conservatively assumed to be elevated by the difference between the off-normal and normal ambient temperatures. The HI-STORM UMAX extreme ambient temperatures computed in this manner are reported in Table 4.6.1. The co-incident MPC pressure is also computed (Table 4.6.5) and compared with the off-normal design pressure (Table 2.3.5), which shows a positive safety margin. The results are confirmed to be below the corresponding limits in Chapter 2.
4.6.1.2 Partial Blockage of Air Inlets The HI-STORM UMAX system is designed with debris screens installed on the inlet and outlet openings. These screens ensure the air passages are protected from entry and blockage by foreign objects. However, as required by the design criteria presented in Chapter 2, it is postulated that the HI-STORM UMAX air inlet vents are 50% blocked*. The resulting decrease in flow area increases the flow resistance of the inlet ducts. The effect of the increased flow resistance on fuel temperature is analyzed assuming that steady state conditions have been reached for the governing thermal configuration established by a series of thermal analyses in Section 4.4 in the foregoing. The computed temperatures and pressures are reported in Tables 4.6.1 and 4.6.5 respectively. The results are confirmed to be below the allowable limits for both internal pressure and temperature limits presented in Tables 2.3.5 and 2.3.7 respectively.
4.6.1.3 Off-Normal Pressure This event is defined as a combination of (a) maximum helium backfill pressure permitted, (b) 10% fuel rods rupture, (c) governing thermal configuration, and (d) normal ambient temperature
- The off-normal condition with partial blockage of air inlet vents is not applicable to HI-STORM UMAX Version B2 design as it has 100% blocked inlet vents.
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-59 to Holtec Letter 5021073
[4.2.13] Hagrman, Reymann and Mason, MATPRO-Version 11 (Revision 2) A Handbook of Materials Properties for Use in the Analysis of Light Water Reactor Fuel Rod Behavior, NUREG/CR-0497, Tree 1280, Rev. 2, EG&G Idaho, August 1981.
[4.2.14] Effective Thermal Conductivity and Edge Conductance Model for a Spent-Fuel Assembly, R. D. Manteufel & N. E. Todreas, Nuclear Technology, 105, 421- 440, (March 1994).
[4.2.15] Aluminum Alloy 2219 Material Data Sheet, ASM Aerospace Specification Metals, Inc.,
Pompano Beach, FL.
[4.4.1] Identifying the Appropriate Convection Correlation in FLUENT for Ventilation Air Flow in the HI-STORM System, Revision 1, Holtec Report HI-2043258, Holtec International, Marlton, NJ, 08053.
[4.4.2] Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer, ASME V&V 20-2009.
[4.4.3] FLUENT Computational Fluid Dynamics Software, Fluent, Inc., Centerra Resource Park, 10 Cavendish Court, Lebanon, NH 03766.
[4.4.4] The TN-24P PWR Spent-Fuel Storage Cask: Testing and Analyses, EPRI NP-5128, (April 1987).
[4.4.5] [
PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390
]
[4.4.6] Performance Testing and Analyses of the VSC-17 Ventilated Concrete Cask, EPRI TR-100305, (May 1992).
[4.4.7] Procedure for Estimating and Reporting of Uncertainty due to Discretization in CFD Applications, I.B. Celik, U. Ghia, P.J. Roache and C.J. Freitas (Journal of Fluids Engineering Editorial Policy on the Control of Numerical Accuracy).
[4.4.8] [PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390]
[4.4.9] FRAPCON-3: Modifications to Fuel Rod Material Properties and Performance Models for High-Burnup Application, D. D. Lanning, C. E. Beyer and C. L. Painter, NUREG/CR-6534, Volume 1, PNNL-11513.
[4.4.10] [PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390]
[4.4.11] [PROPRIETARY INFORMATION WITHHELD IN ACCORDANCE WITH 10 CFR 2.390]
HOLTEC INTERNATIONAL COPYRIGHTED MATERIAL HI-2115090 Proposed Rev. 87 4-76