CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 1,597	$ 523	$ 521
Cash flows from operating activities
Net income (loss)	1,360	1,135	500
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation and amortization (including amortization of debt issuance costs and premiums/discounts)	2,293	2,160	2,235
Amortization of nuclear fuel cost	308	364	371
Non-cash retirement benefit expense	148	138	241
Amortization of Regulatory Asset	63	71	31
Changes in current assets and liabilities
Accounts receivable, net	(209)	(16)	301
Inventories and other current assets, net	(56)	(70)	(83)
Accounts payable and accrued liabilities	61	44	(1)
Accrued interest	67	8	(1)
Pension contributions	(310)	(304)	(306)
Asset Retirement Obligation, Cash Paid to Settle	(258)	(283)	(327)
Other, net	(143)	(102)	(89)
Net cash provided by operating activities	3,324	3,003	2,872
Cash flows from investing activities
Construction expenditures	(4,457)	(3,281)	(2,526)
Nuclear fuel expenditures	(224)	(294)	(273)
Acquisition of leasehold interests in combustion turbine assets	0	0	155
Purchases of investments	(48)	(52)	(51)
Payments to Acquire Loans Receivable	0	4	7
Loans and other receivables
Repayments	12	6	8
Other, net	56	34	10
Net cash used in investing activities	(4,661)	(3,591)	(2,994)
Long-term debt
Issues of power bonds	3,967	991	992
Redemptions and repurchases of power bonds	(1,022)	(1,022)	(29)
Payments on debt of variable interest entities	(41)	(35)	(39)
Short-term debt issues (redemptions), net	(1,166)	734	(740)
Finance Lease, Principal Payments	82	76	56
Financing costs, net	(30)	(5)	(4)
Other, net	(15)	3	(1)
Net cash (used in) provided by financing activities	2,411	590	123
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		2	1
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	1,074
Proceeds from Issuance of Debt	$ 800	$ 0	$ 0