DOE orders Centralia Unit 2 availability for 90 days at TransAlta (TAC)

Rhea-AI Filing Summary

TransAlta Corporation filed a report as a foreign private issuer. The filing references an exhibit describing that the Department of Energy has mandated that Centralia Unit 2 remain available for operation for 90 days. The report is signed on behalf of TransAlta by Joel Hunter, Executive Vice President Finance and Chief Financial Officer.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of December 2025

Commission File Number: 001-15214

TransAlta Corporation
(Translation of registrant's name into English)

Suite 1400, 1100 – 1st Street S.E., Calgary, Alberta, T2G 1B1
(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F [   ]      Form 40-F [ X ]

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

		TransAlta Corporation
		(Registrant)
Date: December 17, 2025		/s/ Joel Hunter
		Joel Hunter
		Executive Vice President Finance and Chief Financial Officer

EXHIBIT INDEX

Exhibit Number		Description
99.1		Department of Energy Mandates Centralia Unit 2 Remain Available for Operation for 90 Days

FAQ

What key event involving TransAlta (TAC) is referenced in this Form 6-K?

The filing references an exhibit stating that the Department of Energy has mandated that Centralia Unit 2 remain available for operation for 90 days.

Which government body issued the mandate related to Centralia Unit 2 for TransAlta (TAC)?

The mandate was issued by the Department of Energy, as described in the exhibit referenced in the filing.

How long must Centralia Unit 2 remain available for operation according to the mandate affecting TransAlta (TAC)?

Centralia Unit 2 is mandated to remain available for operation for 90 days.

Who signed the December 2025 Form 6-K on behalf of TransAlta (TAC)?

The report was signed by Joel Hunter, Executive Vice President Finance and Chief Financial Officer of TransAlta Corporation.

What type of SEC report did TransAlta (TAC) file for December 2025?

TransAlta filed a Form 6-K report of a foreign private issuer under the Securities Exchange Act of 1934.