Nuclear Decommissioning

9 Months Ended

Sep. 30, 2024

Asset Retirement Obligation Disclosure [Abstract]

Nuclear Decommissioning Asset Retirement Obligations

We have a legal obligation to decommission our nuclear power plants following the permanent cessation of operations. See Note 10 — Asset Retirement Obligations of our 2023 Form 10-K for additional information regarding AROs and the financial statement impact of changes in estimate.

The following table provides a rollforward of the nuclear decommissioning AROs reflected in the Consolidated Balance Sheets from December 31, 2023 to September 30, 2024:


Balance as of December 31, 2023(a)	$	13,891
Net decrease due to changes in, and timing of, estimated future cash flows	(2,275)
Accretion expense	488
ARO transferred to Liabilities held for sale	(22)
Costs incurred related to decommissioning plants	(21)
Balance as of September 30, 2024(a)	$	12,061

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(a)Includes $14 million and $30 million as the current portion of the ARO as of September 30, 2024 and December 31, 2023, respectively, which is included in Other current liabilities in the Consolidated Balance Sheets.

During the nine months ended September 30, 2024, the net $2,275 million decrease in the ARO for the changes in the amounts and timing of estimated decommissioning cash flows was driven by multiple adjustments, including the following:

•Net decrease of approximately $2,940 million due to changes in assumed retirement dates for various plants, including Braidwood, Byron, Calvert Cliffs, FitzPatrick, LaSalle, Limerick, NMP Unit 2, Quad Cities, and Crane.

•A decrease of approximately $138 million related to a change in assumed timing of DOE acceptance of SNF.

•An increase of approximately $803 million due to an increase in cost escalation rates and lower discount rates.

The 2024 ARO update resulted in a decrease of $78 million in Operating and maintenance expense for the three and nine months ended September 30, 2024 in the Consolidated Statements of Operations and Comprehensive Income. The 2023 ARO update resulted in a decrease of $68 million in Operating and maintenance expense for the three and nine months ended September 30, 2023 in the Consolidated Statements of Operations and Comprehensive Income.

NDT Funds

We had NDT funds totaling $17,798 million and $16,398 million as of September 30, 2024 and December 31, 2023, respectively. As of September 30, 2024, $104 million of the NDT funds were current and included in Other current assets in the Consolidated Balance Sheets. As of December 31, 2023, none of the NDT funds were reflected in Other current assets. See Note 16 — Supplemental Financial Information for additional information on activities of the NDT funds.

Accounting Implications of the Regulatory Agreement Units

See Note 1 — Basis of Presentation and Note 10 — Asset Retirement Obligations of our 2023 Form 10-K for additional information on the Regulatory Agreement Units.

The following table presents our noncurrent payables to ComEd, PECO, CenterPoint, and AEP Texas reflected as Payables related to Regulatory Agreement Units in the Consolidated Balance Sheets as of September 30, 2024 and December 31, 2023:


	September 30, 2024		December 31, 2023
ComEd	$	3,983	$	2,955
PECO	338		278
CenterPoint	375		338
AEP Texas	132		117
Payables related to Regulatory Agreement Units	$	4,828	$	3,688

NRC Minimum Funding Requirements

NRC regulations require that licensees of nuclear generating facilities demonstrate reasonable assurance that funds will be available in specified minimum amounts for radiological decommissioning of the facility at the end of its life.

In March 2024, we filed our annual decommissioning funding status report with the NRC for our shutdown units, including Zion Station, which was transferred back to us in November 2023. The status report demonstrated adequate decommissioning funding assurance as of December 31, 2023 for all our shutdown units except for Peach Bottom Unit 1. Financial assurance for decommissioning Peach Bottom Unit 1 is provided by collections from PECO customers. Additionally in March 2024, STPNOC filed the decommissioning funding status report for STP. The status report demonstrated adequate funding assurance as of December 31, 2023. See Note 10 — Asset Retirement Obligations of our 2023 Form 10-K for additional information.