ULNRC-06911, Updated 10 CFR 72.30 to Status of ISFSI Decommissioning Funding Plan
| ML24353A226 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 12/18/2024 |
| From: | Ameren Missouri, Union Electric Co |
| To: | Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML24353A223 | List: |
| References | |
| ULNRC-06911 | |
| Download: ML24353A226 (1) | |
Text
Updated Callaway Energy Center 10 CFR 72.30 ISFSI Decommissioning Funding Plan Attachment to ULNRC-06911
Prepared by Ameren Missouri 8315 County Road 459 Steedman, MO 65077 Information supplied by Ameren Services Updated Callaway Energy Center 10 CFR 72.30 ISFSI Decommissioni ng F unding Plan
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 2
Table of Contents BACKGROUND AND INTRODUCTION 3
SPENT FUEL MANAGEMENT STRATEGY 3
ISFSI DECOMMISSIONING STRATEGY 5
ISFSI DESCRIPTION 5
KEY ASSUMPTIONS / ESTIMATING APPROACH 6
COST ESTIMATE 8
FINANCIAL ASSURANCE 9
TABLE 1 SIGNIFICANT QUANTITIES AND PHYSICAL DIMENSIONS 12 TABLE 2 ISFSI DECOMMISSIONING COSTS AND WASTE VOLUMES 13
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 3
Background and Introduction The Nuclear Regulatory Commission (NRC) issued its final rule on Decommissioning Planning on June 17, 2011, [1] with the rule becoming effective on December 17, 2012. Subpart 72.30, Financial assurance and recordkeeping for decommissioning, requires that each holder of, or applicant for, a license under this part must submit for NRC review and approval a decommissioning funding plan that contains information on how reasonable assurance will be provided that funds will be available to decommission the Independent Spent Fuel Storage Installation (ISFSI).
In accordance with the rule, a detailed cost estimate is provided herein for decommissioning the ISFSI at Callaway Energy Center (Callaway) in an amount reflecting:
- 1. The work to be performed by an independent contractor,
- 2. An adequate contingency factor, and
- 3. Release of the facility and dry storage systems for unrestricted use, as specified in 10 CFR Part 20.1402 The following are also provided herein:
- 1. Identification of the key assumptions contained in the cost estimate, and
- 2. The volume of onsite subsurface material containing residual radioactivity, if any, that will require remediation to meet the criteria for license termination.
Spent Fuel Management Strategy The operating license for Callaway, renewed on March 6, 2015, is set to expire on October 18, 2044.
Approximately 3,782 spent fuel assemblies are currently projected to be generated over the life of the plant. Because of the breach by the Department of Energy (DOE) of its contract to remove fuel from the site, an ISFSI has been constructed with spent fuel planned to be transferred to the dry storage 1
U.S. Code of Federal Regulations, Title 10, Parts 20, 30, 40, 50, 70 and 72 "Decommissioning Planning," Nuclear Regulatory Commission, Federal Register Volume 76, Number 117 (p 35512 et seq.), June 17, 2011.
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 4
modules located at the ISFSI, to support continued plant operations. The ISFSI is operated under a Part 50 General License (in accordance with 10 CFR 72, Subpart K[2]).
Completion of the ISFSI decommissioning process is dependent upon the DOEs ability to remove spent fuel from the site. DOEs repository program assumes that spent fuel allocations will be accepted for disposal from the nations commercial nuclear plants, with limited exceptions, in the order in which it was discharged from the reactor.[3]
In January 2013, the DOE issued a report, Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste, in response to the recommendations made by the Blue Ribbon Commission on Americas Nuclear Future and as a framework for moving toward a sustainable program to deploy an integrated system capable of transporting, storing, and disposing of used nuclear fuel...[4] The report stated, [W]ith the appropriate authorizations from Congress, the Administration currently plans to implement a program over the next 10 years that: [A]dvances toward the siting and licensing of a larger interim storage facility to be available by 2025 that will have sufficient capacity to provide flexibility in the waste management system and allows for acceptance of enough used nuclear fuel to reduce expected government liabilities; Based upon DOEs latest strategy, Ameren Missouri believes that one or more monitored interim storage facilities could be put into place within a reasonable time. Ameren Missouris current spent fuel management plan for the Callaway spent fuel is based in general upon the spent fuel being fully removed from the Callaway site by 2050. The estimates described in this analysis were developed based on this assumption that DOE would remove spent fuel from the site by 2050, thus allowing decommissioning of the ISFSI to proceed.
Ameren Missouris position is that the DOE has a contractual obligation to accept the spent fuel earlier than the projections set out above consistent with its contract commitments. No assumption made in this study should be interpreted to be inconsistent with this position.
2 U.S. Code of Federal Regulations, Title 10, Part 72, Subpart K, General License for Storage of Spent Fuel at Power Reactor Sites.
3 U.S. Code of Federal Regulations, Title 10, Part 961.11, Article IV - Responsibilities of the Parties, B. DOE Responsibilities, 5.(a) DOE shall issue an annual acceptance priority ranking for receipt of SNF and/or HLW at the DOE repository. This priority ranking shall be based on the age of SNF and/or HLW as calculated from the date of discharge of such materials from the civilian nuclear power reactor. The oldest fuel or waste will have the highest priority for acceptance, except as 4
Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste, U.S. DOE, January 11, 2013.
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 5
ISFSI Decommissioning Strategy At the conclusion of the spent fuel transfer process the ISFSI will be promptly decommissioned (similar to the power reactor DECON alternative).
For purposes of providing an estimate for a funding plan, financial assurance is expected to be provided on the basis of a prompt ISFSI decommissioning scenario. In this estimate the ISFSI decommissioning is considered an independent project, regardless of the decommissioning alternative identified for the nuclear power plant.
ISFSI Description The Callaway ISFSI is based upon Holtec Internationals (Holtec) HI-STORM UMAX underground system for the dry storage of used nuclear fuel. In this system, spent fuel is stored in a multi-purpose container (MPC) and placed within an underground vertical ventilated module (VVM). The ISFSI pad is designed for 48 VVMs, although all the cells may not be needed, depending upon DOE performance.
In addition to the spent fuel stored at the ISFSI, there is projected to be five additional modules used for Greater-than-Class-C (GTCC) waste storage. The multi-purpose containers used for this GTCC waste canister are also expected to be transferred to the DOE at the same time as the spent fuel transfer.
The key constituent of a HI-STORM UMAX VVM is the Cavity Enclosure Container (CEC). The CEC is a closed bottom, open top, thick-walled cylindrical vessel that has no penetrations or openings. The closure lid completes the physical embodiment of the HI-STORM UMAX VVM once the loaded MPC is placed inside the CEC. The closure lid is a steel structure filled with plain concrete and is designed to protect the VVM from the impact of design basis missiles as well as to provide an inlet and outlet for air flow.
The wall thickness of the welded steel CEC is approximately 3/4 inches. The CEC rests on a foundation pad with a thickness of 2 feet 9 inches, approximately 16 feet 11 inches below the grade-level ISFSI pad.
A divider shell divides the CEC into an inlet flow downcomer and an outlet flow passage. It is a vertical cylindrical shell concentrically situated in the CEC and is not attached to the CEC, which allows its convenient removal for decommissioning.
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Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 6
All exposed surfaces of the CEC are made from ferritic steels that are painted and protected from corrosion. The inside surface of the CECs and the divider shells is protected by paint. In addition, one side of the divider shell is further protected by insulation.
The VVMs are surrounded by controlled low-strength material (CLSM), a self-compacted, cementitious material.
A reinforced concrete slab (ISFSI pad) surrounds the upper portion of the CEC and extends to the underside of the CEC Flange. The ISFSI pad provides robust support for a loaded transporter and enables rainwater to flow away from the storage array. The concrete ISFSI pad is approximately 2 feet 6 inches thick.
Ameren Missouris current spent fuel management plan for the Callaway spent fuel would result in all 48 MPCs being placed at the ISFSI by the year 2044, excluding GTCC.
The storage modules used for the GTCC canisters (estimated quantity of 5) are not expected to have any interior contamination or residual activation and can be reused or disposed of by conventional means after a final status survey.
Table 1 provides the significant quantities and physical dimensions used as the basis in developing the ISFSI decommissioning estimate.
Key Assumptions / Estimating Approach The decommissioning estimate is based on the configuration of the ISFSI expected after all spent fuel and GTCC material has been removed from the site. The configuration of the ISFSI is based on the station operating until the end of its current license (2044) and the DOEs spent fuel acceptance assumptions, as previously described.
The dry storage vendor, Holtec, does not expect the VVMs to have any interior or exterior radioactive surface contamination.[5] It is expected that this assumption would be confirmed as a result of good radiological practice of surveying potentially impacted areas after each spent fuel transfer campaign.
Any neutron activation of the steel and concrete is expected to be extremely small.[6] This assumption is adopted for this analysis.
5 Final Safety Analysis Report for the HI-STORM UMAX Canister Storage System, FSAR Report No. HI-2115090, Rev. 1, at page 2-120.
6 Ibid.
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Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 7
The decommissioning estimate is based on the conservative premise that a small percentage of the VVMs would contain very low levels of neutron-induced residual radioactivity that would necessitate remediation at the time of decommissioning. As an allowance, 6 of the 48 MPCs are assumed to be affected, i.e., contain residual radioactivity. The allowance quantity is based upon the number of MPCs required for the final core off-load (i.e., 193 offloaded assemblies/unit, 37 assemblies per MPC) which results in a total of 6 VVMs that contain residual radioactivity. It is assumed that these are the final VVMs offloaded; consequently, they have the least time for radioactive decay of the neutron activation products.
It is not expected that there will be any residual contamination left on the concrete ISFSI pad. It is expected that this assumption would be confirmed as a result of good radiological practice of surveying potentially impacted areas after each spent fuel transfer campaign. Therefore, it is assumed for this analysis that the ISFSI pad will not be contaminated. As such, only verification surveys are included for the pad in the decommissioning estimate.
The ISFSI storage modules were constructed in the original Callaway unit 2 excavation, after the non-usable sediment was removed and replaced with clean fill. The clean fill was obtained from a borrow pit and suppliers located outside of the Owner Control Area and not radiologically affected by plant Operations. It is assumed that there is no subsurface soil in the proximity of the ISFSI containing residual radioactivity that will require remediation to meet the criteria for license termination.
Costs are reported in 2023 dollars and based upon the triennial decommissioning analysis prepared for Callaway in September, 2023.[7]
Decommissioning is assumed to be performed by an independent contractor. As such, essentially all labor, equipment, and material costs are based on national averages, i.e., costs from national publications such as R.S. Means Building Construction Cost Data (adjusted for regional variations),
and laboratory service costs are based on vendor price lists. Ameren Missouri, as licensee, will oversee the site activities. The estimate includes Ameren Missouris labor and overhead costs.
Low-level radioactive waste packaging, transport and disposal costs are based on rates consistent with the most recently developed decommissioning cost estimate.
Contingency has been added at an overall rate of 25% to the license termination tasks. This is consistent with the contingency evaluation criteria referenced by the NRC in NUREG-1757.[8]
7 Decommissioning Cost Analysis for the Callaway Energy Center, TLG Services, Inc. Document A22-1819-001, Rev. 0, dated September 2023.
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Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 8
The estimate is limited to costs necessary to terminate the ISFSIs NRC license and meet the 10 CFR 20.1402 criteria for unrestricted use. Disposition of released material and structures is outside the scope of the estimate.
The effects, if any, since the last submittal of the ISFSI decommissioning funding plan of the following events listed in 10 CFR 72.30 (c) (1)-(4) have been specifically considered in the decommissioning cost estimate:
(1) Spills of radioactive material producing additional residual radioactivity in onsite subsurface material: There have been no spills at the ISFSI.
(2) Facility modifications: There have been no facility modifications in the past three years that affect the decommissioning cost estimate.
(3) Changes in authorized possession limits: There are no changes in authorized possession limits that affect the decommissioning cost estimate.
(4) Actual remediation costs that exceed the previous cost estimate: No actual remediation costs have been incurred, so no actual remediation costs exceed the previous cost estimate.
Cost Estimate The estimated cost to decommission the ISFSI and release the facility for unrestricted use is provided in Table 2. The cost has been organized into three phases, including:
An initial planning phase - empty VVMs are characterized and the specifications and work procedures for the decontamination (MPC support structure removal) developed.
The remediation phase - residual radioactivity is removed. The empty VVMs are used as waste containers, transported to the low-level waste site, and disposed of at low-level waste.
The final phase - license termination surveys and independent surveys are completed, and an application for license termination submitted.
8 Consolidated Decommissioning Guidance - Financial Assurance, Recordkeeping, and Timeliness, U.S. Nuclear Regulatory Commissions Office of Nuclear Material Safety and Safeguards, NUREG-1757, Volume 3, Revision 1, February 2012
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 9
In addition to the direct costs associated with a contractor providing the decommissioning services, the estimate also contains costs for the NRC (and NRC contractor to perform the verification survey),
Ameren Missouris oversight staff, site security (industrial), and other site operating costs.
For estimating purposes it should be conservatively assumed that all license termination expenditures will be incurred in year 2050, following all spent fuel removal.
Financial Assurance This section describes the methodology by which Ameren Missouri is providing financial assurance for decommissioning the ISIFI at the end of its useful life.
ISFSI operations at Callaway are required due to the DOEs) failure to remove spent nuclear fuel from the Callaway Energy Center in a timely manner pursuant to a written agreement. The costs for management of the spent fuel are costs for which the DOE is responsible under federal law and the Standard Contract.
It is uncertain as to whether the DOE will actually provide reimbursement for the ISFSI decommissioning costs, and if such reimbursement is provided, when it will occur.
Consequently, Ameren Missouri intends to provide financial assurance for the ISFSI decommissioning utilizing the External Sinking Fund methodology, as described in the following CFR paragraphs:
10 CFR 72.30(e) states (in part):
(e). Financial assurance for decommissioning must be provided by one or more of the following methods:
(5)
In the case of licensees who are issued a power reactor license under part 50 of this chapter or ISFSI licensees who are an electric utility, as defined in part 50 of this chapter, with a specific license issued under this part, the methods of 10 CFR 50.75(b), (e), and (h), as applicable. In the event that funds remaining to be placed into the licensees ISFSI decommissioning external sinking fund are no longer approved for recovery in rates by a competent rate making authority, the licensee must make changes to provide financial assurance using one or more of the methods stated in paragraphs (1) through (4) of this section.
As Ameren Missouri has been issued a power reactor license and is an electric utility, it meets the foregoing criteria and consequently is utilizing the External Sinking Fund method of providing financial assurance for decommissioning the ISFSI, as defined in 10 CFR 50.75(e)(1)(ii). This is also
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 10 the financial assurance method that Ameren Missouri currently uses for the Callaway Energy Center Part 50 license termination.
Separate, segregated sub-accounts have been established within the external sinking fund to segregate the ISFSI decommissioning funding from the plant decommissioning funding.
Missouri regulations, cited below, require the triennial filing of updated decommissioning cost estimates and associated funding levels required for decommissioning funding assurance. Missouri regulations also provide for the changing of rates charged to ratepayers to recover any changes in funding levels necessitated by the triennial decommissioning cost estimate updates.
20 CSR 4240-20.070 Decommissioning Trust Funds (4)
Every three (3) years, utilities with decommissioning trust funds shall perform and file with the commission cost studies detailing the utilities latest cost estimates for decommissioning their nuclear generating unit(s) along with the funding levels necessary to defray these decommissioning costs.
These studies shall be filed along with appropriate tariff(s) effectuating the change in rates necessary to accomplish the funding required. In addition, the commission, at any time for just cause, may require a utility to file an updated decommissioning cost study, funding requirement, and associated tariff(s).
and (9)
Upon the filing of the appropriate tariff(s) as set forth in this rule, the commission shall establish a schedule of proceedings which shall be limited in scope to the following issues:
(A)
The extent of any change in the level or annual accrual of funding necessary for the utilitys decommissioning trust fund; and (B)
The changes in rates which would reflect any change in the funding level or accrual rate.
To comply with the foregoing Missouri regulations, Ameren Missouri prepares an updated site-specific decommissioning cost estimate for the Callaway Energy Center every three (3) years and files this estimate and an updated funding level analysis with the Missouri Public Service Commission (MPSC).
The site-specific estimate includes radiological license termination expenses, non-radiological site restoration expenses and spent fuel management expenses. The funding level analysis is based on this total decommissioning cost estimate amount. Although the external sinking fund described in 10 CFR 50.75 is for radiological decommissioning costs only, to the extent that the fund balance exceeds costs required for Part 50 radiological decommissioning, excess funds would be available for non-radiological site restoration expenses and spent fuel management expenses.
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 11 The most recent triennial update filing was made with the MPSC on December 1, 2023.
As part of this December 1, 2023, MPSC filing, Ameren Missouri had a decommissioning cost estimate for the ISFSI prepared by the same firm that prepared the cost estimate for the Callaway Energy Center decommissioning. The estimated cost for radiological decommissioning of the ISFSI and release of the facility for unrestricted use is $10,556,000 (2023$). This estimate projects that license termination of the ISFSI will take place in 2050. As of December 2024, this filing is currently under review by the Missouri Public Service Commission. therefore the February 9, 2021 stipulation agreement remains in effect.
On February 9,
- 2021, Ameren Missouri and the MPSC Staff entered into a
"Non-Unanimous Stipulation and Agreement" regarding the cost estimates for decommissioning of the plant and ISFSI and the associated funding levels of the nuclear decommissioning trust fund. The MPSC approved the "Non-Unanimous Stipulation and Agreement" in an Order issued February 24, 2021.9 Based on the approved cost estimate and funding plan, Ameren Missouri is making annual contributions of $516,379 to the segregated ISFSI sub-accounts of the external sinking fund.
This funding level commenced as of January 1, 2021, and remains in effect until the next approval by the MPSC.
Ameren Missouri will refund to Missouri ratepayers any DOE reimbursement amounts received for costs of decommissioning the ISFSI whereby Ameren Missouri previously collected those decommissioning costs from Missouri ratepayers as Missouri rate tariffs.
As 10 CFR 72.30 (c) states, in part:
(c)
At the time of license renewal and at intervals not to exceed 3 years, the decommissioning funding plan must be resubmitted with adjustments as necessary to account for changes in costs and the extent of contamination.
To comply with this requirement, Ameren Missouri obtains updated site-specific decommissioning cost estimates for the ISFSI concurrently with updated plant decommissioning cost estimates and files both on a triennial basis with the MPSC, along with updated funding level analyses, as required by Missouri regulations. The next filing will be made by September 1, 2026, (and then every three (3) years thereafter). Concurrent with these MPSC filings, updated ISFSI cost estimates and funding level analyses are submitted to the NRC in accordance with 10 CFR 72.30(c).
9 Copies of the ISFSI decommissioning cost estimate, the "Funding Adequacy Analysis," the "Non-Unanimous Stipulation and Agreement" and the February 24, 2021 MPSC Order are available on request.
Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 12 Table 1 Significant Quantities and Physical Dimensions ISFSI Pad Item Length (feet)
Width (feet)
Depth (feet)
Residual Radioactivity ISFSI Pad 157.5 143.5 2.5 No ISFSI HI-STORM UMAX Item Value Notes (all dimensions are nominal)
Cavity Enclosure Container Inside Height (inches) 181 Cavity Enclosure Container Inside Diameter (inches) 86 Quantity (total) 53 Spent Fuel (43) + GTCC (5)
Quantity (with residual radioactivity) 6 Equivalent to the number of VVMs used to store last complete core offload)
Potentially Activated Steel and Concrete (pounds) 847,767 Misc. Low-Level Radioactive Waste (pounds) 3,289 Low-Level Radioactive Waste (cubic feet) 13,299 Excluding transfer cask Low-Level Radioactive Waste (packaged density) 75 Average weight density Other Potentially Impacted Items Item Value Notes Number of VVMs used for GTCC storage 5 No residual radioactivity
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Ameren Missouri: December 2024 10 CFR 72.30 ISFSI Decommissioning Funding Plan, Revision 3 13 Table 2 ISFSI Decommissioning Costs1 and Waste Volumes Costs (thousands, 2023 dollars)
Waste Volume Person-Hours Removal Packaging Transport Disposal Other Total Cubic Feet Craft Oversight and Contractor Decommissioning Contractor Planning (characterization, specs and procedures) 280 280 1,048 Remediation (activated metal removal) 684 154 166 3,547 4551 14,077 7,706 License Termination (radiological surveys) 1,588 1588 9,866 Subtotal 684 154 166 3547 1,868 6418 14,077 17,572 1,048 Supporting Costs NRC and NRC Contractor Fees 572 572 1,153 Insurance 144 144 Property Taxes 39 39 Plant Energy Budget 13 13 Corporate A&G 329 329 Security (industrial) 557 557 4,958 Ameren Missouri Oversight 372 372 3,761 Subtotal 2026 2026 9,872 Total (w/o contingency) 684 154 166 3547 3894 8444 14,077 17,572 10,920 Total (w/25% contingency) 854 193 208 4433 4,867 10,556 Note 1: For funding planning purposes costs can be assumed to be incurred in 2050
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