Asset Retirement Obligations

6 Months Ended

Mar. 31, 2023

Asset Retirement Obligation Disclosure [Abstract]

During the six months ended March 31, 2023, TVA's total asset retirement obligations ("ARO") liability decreased $26 million as a result of settlements related to retirement projects that were conducted during the period, partially offset by periodic accretion. The nuclear and non-nuclear accretion amounts were deferred as regulatory assets. During the six months ended March 31, 2023, $94 million of the related regulatory assets were amortized into expense as these amounts were collected in rates. See Note 8 — Regulatory Assets and Liabilities. TVA maintains investment trusts to help fund its decommissioning obligations. See Note 14 — Fair Value Measurements — Investment Funds and Note 20 — Contingencies and Legal Proceedings — Contingencies — Decommissioning Costs for a discussion of the trusts' objectives and the current balances of the trusts.


Asset Retirement Obligation Activity
	Nuclear		Non-Nuclear		Total
Balance at September 30, 2022	$	3,643	$	3,519	$	7,162	(1)
Settlements	—		(122)		(122)		(2)
Revisions in estimate	6		(27)		(21)


Accretion (recorded as regulatory asset)	82		35		117

Balance at March 31, 2023	$	3,731	$	3,405	$	7,136	(1)

Notes

(1) Includes $270 million and $275 million at March 31, 2023, and September 30, 2022, respectively, in Current liabilities.

(2) Settlements include the change in asset retirement obligation project accruals included in Accounts payable and accrued liabilities of ($72) million.