Asset Retirement Obligations and Accrued Environmental Costs

9 Months Ended

Sep. 30, 2024

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations and Accrued Environmental Costs

9. Asset Retirement Obligations and Accrued Environmental Costs

	Successor
	September 30, 2024		December 31, 2023
Asset retirement obligations	$	495	$	464
Accrued environmental costs	22		23
Total asset retirement obligations and accrued environmental costs	517		487
Less: asset retirement obligations and accrued environmental costs due within one year (a)	42		18
Asset retirement obligations and accrued environmental costs due after one year	$	475	$	469

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(a)Presented as “Other current liabilities” on the Consolidated Balance Sheets.

Asset Retirement Obligations

The changes of the ARO carrying value were:

	ARO Rollforward
Carrying value, December 31, 2023 (Successor)	$	464
Obligations settled	(9)
Accretion expense	40
Carrying value, September 30, 2024 (Successor)	$	495

Supplemental information for the ARO:

	Successor
	September 30, 2024		December 31, 2023
Supplemental Information
Nuclear (a)	$	234	$	214
Non-Nuclear (b)	261		250
Carrying value	$	495	$	464

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(a)Obligations are expected to be settled with available funds in the NDT at the time of decommissioning. See Note 12 for additional information on the NDT.

(b)Certain obligations are: (i) partially supported by surety bonds, some of which have been collateralized with cash and (or) LCs; or (ii) partially prefunded under phased installment agreements.

As a result of environmental regulations issued by the EPA or other rule-making entities, the Company may be required to revise and (or) recognize new AROs. See “Environmental Matters” in Note 10 for additional information. See “Talen Montana Financial Assurance” in Note 10 for information on Talen Montana’s requirement to provide financial assurance for certain environmental decommissioning and remediation liabilities related to Colstrip.