XML 49 R15.htm IDEA: XBRL DOCUMENT
v3.19.1

Asset Retirement Obligations | 6 Months Ended
--- | ---
Mar. 31, 2019
Asset Retirement Obligation Disclosure [Abstract] |
Asset Retirement Obligations | Asset Retirement Obligations During the six months ended March 31, 2019, TVA's total asset retirement obligations ("ARO") liability increased $198 million as a result of revisions in estimates and periodic accretion, partially offset by settlement activity from ongoing ARO projects at TVA facilities. The nuclear and non-nuclear accretion amounts were deferred as regulatory assets. During the six months ended March 31, 2019, $72 million of the related non-nuclear regulatory assets were amortized into expense as these amounts were collected in rates. See Note 7. TVA maintains investment trusts to help fund its decommissioning obligations. See Note 15 — Investment Funds and Note 19 — Contingencies — Decommissioning Costs for a discussion of the trusts' objectives and the current balances of the trusts.
Asset Retirement Obligation Activity(1)
| Nuclear |  | Non-Nuclear |  | Total
Balance at September 30, 2018 | $ | 2,989 |  |  | $ | 1,790 |  |  | $ | 4,779 |
Settlements | — |  |  | (42 | ) |  | (42 | )
Revisions in estimate | — |  |  | 136 |  |  | 136 |
Additional Obligation | 14 |  |  | — |  |  | 14 |
Accretion (recorded as regulatory asset) | 67 |  |  | 23 |  |  | 90 |
Balance at March 31, 2019 | $ | 3,070 |  |  | $ | 1,907 |  |  | $ | 4,977 |
Note (1) The current portion of ARO in the amount of $102 million and $115 million is included in Accounts payable and accrued liabilities at March 31, 2019, and September 30, 2018, respectively. As a result of recent experience in completing settlements at certain facilities, the revisions in non-nuclear estimates increased $103 million primarily due to expected costs for asbestos abatement activities across TVA's fossil fleet. In addition, TVA approved a change in the preferred closure method for the Allen West Impoundment from closure in place to closure by removal, which resulted in a cost increase of $33 million.

X
- References No definition available. + Details
Name: | us-gaap_AssetRetirementObligationDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -URI http://asc.fasb.org/subtopic&trid=2175671 + Details
Name: | us-gaap_AssetRetirementObligationDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration