Nuclear Decommissioning Trust Fund Investments

12 Months Ended

Dec. 31, 2011

Nuclear Decommissioning Trust Fund Investments

NOTE 9 – NUCLEAR DECOMMISSIONING TRUST FUND INVESTMENTS

Ameren Missouri has investments in debt and equity securities that are held in a trust fund for the purpose of funding the decommissioning of its Callaway energy center. See Note 10 – Callaway Energy Center for additional information. We have classified these investments as available for sale, and we have recorded all such investments at their fair market value at December 31, 2011, and 2010.

Investments in the nuclear decommissioning trust fund have a target allocation of 60% to 70% in equity securities, with the balance invested in debt securities.

The following table presents proceeds from the sale of investments in Ameren Missouri's nuclear decommissioning trust fund and the gross realized gains and losses resulting from those sales for the years ended December 31, 2011, 2010, and 2009:

	2011		2010		2009
Proceeds from sales	$	199	$	256	$	380
Gross realized gains		5		5		5
Gross realized losses		4		4		10

Net realized and unrealized gains and losses are deferred and recorded as regulatory assets or regulatory liabilities on Ameren's and Ameren Missouri's balance sheets. This reporting is consistent with the method used to account for the decommissioning costs recovered in rates. Gains or losses associated with assets in the trust fund could result in lower or higher funding requirements for decommissioning costs, which are expected to be reflected in electric rates paid by Ameren Missouri's customers. See Note 2 – Rate and Regulatory Matters.

The following table presents the costs and fair values of investments in debt and equity securities in Ameren Missouri's nuclear decommissioning trust fund at December 31, 2011 and 2010:

Security Type	Cost			Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
2011:
Debt securities	$	114		$	7	$	(a	)	$	121
Equity securities		145			101		12			234
Cash		3			—		—			3
Other(b)		(1	)		—		—			(1	)
Total	$	261		$	108	$	12		$	357
2010:
Debt securities	$	104		$	4	$	1		$	107
Equity securities		141			95		8			228
Cash		1			—		—			1
Other(b)		1			—		—			1
Total	$	247		$	99	$	9		$	337

(a) Amount less than $1 million.

(b) Represents payables relating to pending security purchases, net of receivables related to pending securities sales and interest receivables.

The following table presents the costs and fair values of investments in debt securities in Ameren Missouri's nuclear decommissioning trust fund according to their contractual maturities at December 31, 2011:

	Cost		Fair Value
Less than 5 years	$	57	$	59
5 years to 10 years		34		36
Due after 10 years		23		26
Total	$	114	$	121

We have unrealized losses relating to certain available-for-sale investments included in our decommissioning trust fund, recorded as regulatory assets as discussed above. Decommissioning will not occur until the operating license for our nuclear facility expires. Ameren Missouri submitted a license extension application to the NRC to extend the Callaway energy center's operating license to 2044. The following table presents the fair value and the gross unrealized losses of the available-for-sale securities held in Ameren Missouri's nuclear decommissioning trust fund. They are aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position at December 31, 2011:

	Less than 12 Months					12 Months or Greater						Total
	Fair Value		Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Debt securities	$	7	$	(a	)	$	(a	)	$	(a	)	$	7	$	(a	)
Equity securities		18		4			8			8			26		12
Total	$	25	$	4		$	8		$	8		$	33	$	12

(a) Amount less than $1 million.

Union Electric Company [Member]

Nuclear Decommissioning Trust Fund Investments

NOTE 9 – NUCLEAR DECOMMISSIONING TRUST FUND INVESTMENTS

Ameren Missouri has investments in debt and equity securities that are held in a trust fund for the purpose of funding the decommissioning of its Callaway energy center. See Note 10 – Callaway Energy Center for additional information. We have classified these investments as available for sale, and we have recorded all such investments at their fair market value at December 31, 2011, and 2010.

Investments in the nuclear decommissioning trust fund have a target allocation of 60% to 70% in equity securities, with the balance invested in debt securities.

The following table presents proceeds from the sale of investments in Ameren Missouri's nuclear decommissioning trust fund and the gross realized gains and losses resulting from those sales for the years ended December 31, 2011, 2010, and 2009:

	2011		2010		2009
Proceeds from sales	$	199	$	256	$	380
Gross realized gains		5		5		5
Gross realized losses		4		4		10

Net realized and unrealized gains and losses are deferred and recorded as regulatory assets or regulatory liabilities on Ameren's and Ameren Missouri's balance sheets. This reporting is consistent with the method used to account for the decommissioning costs recovered in rates. Gains or losses associated with assets in the trust fund could result in lower or higher funding requirements for decommissioning costs, which are expected to be reflected in electric rates paid by Ameren Missouri's customers. See Note 2 – Rate and Regulatory Matters.

The following table presents the costs and fair values of investments in debt and equity securities in Ameren Missouri's nuclear decommissioning trust fund at December 31, 2011 and 2010:

Security Type	Cost			Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
2011:
Debt securities	$	114		$	7	$	(a	)	$	121
Equity securities		145			101		12			234
Cash		3			—		—			3
Other(b)		(1	)		—		—			(1	)
Total	$	261		$	108	$	12		$	357
2010:
Debt securities	$	104		$	4	$	1		$	107
Equity securities		141			95		8			228
Cash		1			—		—			1
Other(b)		1			—		—			1
Total	$	247		$	99	$	9		$	337

(a) Amount less than $1 million.

(b) Represents payables relating to pending security purchases, net of receivables related to pending securities sales and interest receivables.

The following table presents the costs and fair values of investments in debt securities in Ameren Missouri's nuclear decommissioning trust fund according to their contractual maturities at December 31, 2011:

	Cost		Fair Value
Less than 5 years	$	57	$	59
5 years to 10 years		34		36
Due after 10 years		23		26
Total	$	114	$	121

We have unrealized losses relating to certain available-for-sale investments included in our decommissioning trust fund, recorded as regulatory assets as discussed above. Decommissioning will not occur until the operating license for our nuclear facility expires. Ameren Missouri submitted a license extension application to the NRC to extend the Callaway energy center's operating license to 2044. The following table presents the fair value and the gross unrealized losses of the available-for-sale securities held in Ameren Missouri's nuclear decommissioning trust fund. They are aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position at December 31, 2011:

	Less than 12 Months					12 Months or Greater						Total
	Fair Value		Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Debt securities	$	7	$	(a	)	$	(a	)	$	(a	)	$	7	$	(a	)
Equity securities		18		4			8			8			26		12
Total	$	25	$	4		$	8		$	8		$	33	$	12

(a) Amount less than $1 million.