XML 85 R29.htm IDEA: XBRL DOCUMENT

Research and Development	12 Months Ended
Research and Development	Sep. 30, 2025
Research and Development [Abstract]
Collaborative Arrangement Disclosure	22. Collaborative Arrangement In 2023, TVA, Ontario Power Generation, BWRX TCA sp. z.o.o., and GE Vernova Hitachi Nuclear Energy ("GVH") entered into a multi-party collaborative arrangement to advance the global deployment of the GVH BWRX-300 small modular reactor. GVH is responsible for standard design development. Under the agreement, TVA will contribute up to $93 million for design costs incurred by GVH 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 Statements of Operations in the period incurred. TVA recorded $11 million and $41 million of expenses related to this agreement for the years ended September 30, 2025 and 2024, respectively. TVA also had a $6 million letter of credit posted under this arrangement at September 30, 2025.