ComEd 2006 Annual Report Download - page 240

Exelon Corporation and Subsidiary Companies
Exelon Generation Company, LLC and Subsidiary Companies
Commonwealth Edison Company and Subsidiary Companies
PECO Energy Company and Subsidiary Companies
Combined Notes to Consolidated Financial Statements—(Continued)
(Dollars in millions, except per share data unless otherwise noted)
Nuclear Decommissioning Trust Fund Investments (Exelon and Generation)
Investments as of December 31, 2006 and 2005. Exelon and Generation classify investments in
trust accounts for decommissioning nuclear plants as available-for-sale and estimate their fair value
based on quoted market prices for the securities held in decommissioning trust funds. These
investments are held to fund Generation’s decommissioning obligation for its nuclear plants.
Decommissioning expenditures are expected to occur primarily after the plants are retired. See Note
13—Asset Retirement Obligations for further information regarding the decommissioning of
Generation’s nuclear plants.
The following tables show the fair values, gross unrealized gains and losses and amortized cost
bases of the securities held in these trust accounts as of December 31, 2006 and 2005:
December 31, 2006
Amortized
Cost
Unrealized
Gains
Unrealized
Losses
Estimated
Fair Value
Cash and cash equivalents .......................... $ 36 $ — $— $ 36
U.S. Treasury obligations and direct obligations of U.S.
government agencies ............................ 990 36 — 1,026
Federal agency mortgage-backed securities ........... 767 6 — 773
Commercial mortgage-backed securities .............. 82 1 — 83
Corporate bonds .................................. 306 7 — 313
Other debt securities ............................... 137 — — 137
Marketable equity securities ......................... 2,810 1,237 — 4,047
Total available-for-sale securities ..................... $5,128 $1,287 $— $6,415
December 31, 2005
Amortized
Cost
Unrealized
Gains
Unrealized
Losses
Estimated
Fair Value
Cash and cash equivalents .......................... $ 80 $— $— $ 80
U.S. Treasury obligations and direct obligations of U.S.
government agencies ............................ 958 37 (3) 992
Federal agency mortgage-backed securities ........... 684 3 (6) 681
Commercial mortgage-backed securities .............. 53 1 (1) 53
Corporate bonds .................................. 303 10 (4) 309
Other debt securities ............................... 58 — (1) 57
Marketable equity securities ......................... 2,762 683 (32) 3,413
Total available-for-sale securities ..................... $4,898 $734 $(47) $5,585
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