<p>Contact: Ralph DeSantis FOR IMMEDIATE RELEASE Three Mile Island Generating Station 717-314-3850 (mobile) 717-948-8930 (office) [email protected]</p><p>Three Mile Island Offline for Electrical System Repairs </p><p>LONDONDERRY TWP, PA. (May 6, 2015) – Operators removed Three Mile Island Unit 1 from service earlier today to repair an electrical component that powers one of the unit’s control rods. This repair cannot be performed while the plant is generating electricity. </p><p>During the course of shutting down the plant, a valve opened allowing steam to be released to the atmosphere. The steam release was audible to nearby residents. </p><p>Three Mile Island Generating Station is located approximately 12 miles south of Harrisburg. The plant generates enough carbon-free electricity for 800,000 homes.</p><p>###</p><p>Exelon Corporation (NYSE: EXC) is the nation’s leading competitive energy provider, with 2014 revenues of approximately $27.4 billion. Headquartered in Chicago, Exelon does business in 48 states, the District of Columbia and Canada. Exelon is one of the largest competitive U.S. power generators, with approximately 32,500 megawatts of owned capacity comprising one of the nation’s cleanest and lowest-cost power generation fleets. The company’s Constellation business unit provides energy products and services to more than 2.5 million residential, public sector and business customers, including more than two-thirds of the Fortune 100. Exelon’s utilities deliver electricity and natural gas to more than 7.8 million customers in central Maryland (BGE), northern Illinois (ComEd) and southeastern Pennsylvania (PECO). Follow Exelon on Twitter @Exelon.</p>