ASSET RETIREMENT OBLIGATIONS (Tables)

3 Months Ended

Mar. 31, 2024

Asset Retirement Obligation [Abstract]

Summary of Asset Retirement Obligations

The following is a summary of our asset retirement obligations:

(In millions)	March 31, 2024		December 31, 2023
Asset retirement obligations1	$	510	$	459
Less: current portion	61		15
Long-term asset retirement obligations	$	449	$	444
1 Includes $263 million and $259 million related to our active operations as of March 31, 2024 and December 31, 2023, respectively.

Schedule of Change in Asset Retirement Obligation

The following is a roll-forward of our asset retirement obligations:

(In millions)	2024		2023
Asset retirement obligations as of January 1	$	459	$	520
Accretion expense	5		8
Revision in estimated cash flows	48		—
Remediation payments	(2)		(4)
Asset retirement obligations as of March 31	$	510	$	524