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Research and Development | 9 Months Ended
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Jun. 30, 2025
Research and Development [Abstract] |
Collaborative Arrangement Disclosure | 20. Collaborative Arrangement In 2023, TVA, Ontario Power Generation, BWRX TCA sp. z.o.o., and GE Hitachi Nuclear Energy ("GEH") entered into a multi-party collaborative arrangement to advance the global deployment of the GEH BWRX-300 small modular reactor. GEH is responsible for standard design development. Under the agreement, TVA will contribute up to $93 million for design costs incurred by GEH through 2026. At the time feasibility is determined, TVA will have the right to use the design and may receive additional economic benefits. Payments pursuant to the agreement are recorded as research and development expense, which is reflected as Operating and maintenance expense on TVA's Consolidated Statement of Operations in the period incurred. TVA recorded no expenses related to this agreement for the three months ended June 30, 2025 and $12 million of expenses for the three months ended June 30, 2024. TVA recorded $10 million and $29 million of expenses related to this agreement for the nine months ended June 30, 2025 and 2024, respectively. TVA also had a $6 million letter of credit posted under this arrangement at June 30, 2025.

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- Definition The entire disclosure for collaborative arrangements in which the entity is a participant, including a) information about the nature and purpose of such arrangements; b) its rights and obligations thereunder; c) the accounting policy for collaborative arrangements; and d) the income statement classification and amounts attributable to transactions arising from the collaborative arrangement between participants. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 808 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479402/808-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 808 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479402/808-10-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Topic 808 -Publisher FASB -URI https://asc.fasb.org/808/tableOfContent + Details
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