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Commitments and Contingencies - Table (Details) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2025 USD ($) megawatts | Sep. 30, 2024 USD ($) | Sep. 30, 2023 USD ($)
Obligations |  |  |  |
Megawatts provided under transmission obligations | megawatts |  | 3,750 |  |
Accrual for Environmental Loss Contingencies, Gross |  | $ 8 | $ 15 |
Estimated future decommissioning cost | [1] | $ 10,414 | 10,806 | $ 7,489
Remaining terms of the transmission obligations, high end of range |  | 6 years |  |
Nuclear |  |  |  |
Obligations |  |  |  |
Estimated future decommissioning cost |  | $ 3,976 | $ 3,814 | $ 3,808
[1] | (1) Includes $313 million and $283 million at September 30, 2025 and 2024, respectively, in Current liabilities.

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