plans to retire its"economically challenged" Clinton and Quad Cities nuclear plants if Illinois lawmakers do notpass adequate legislation and Quad Cities does not clear the 2019-2020PJM InterconnectionLLC capacity auction.

Theretirements would occur on June 1, 2017 and June 1, 2018, respectively, Exelon Presidentand CEO Christopher Crane said in the company's May 6 earnings release.

Thenews came after Exelon GenerationCo. LLC, CommonwealthEdison Co. and other Illinois stakeholders unveiled a new bill May5 that seeks to secure the future of "at-risk nuclear plants." Theso-called Next Generation Energy Plan includes a provision to introduce a ZeroEmission Standard that will "make Illinois one of the first states to recognizethe zero-carbon benefits of nuclear power."

Exelonhad deferred retirement decisions on the facilities in order to participate inthe 2016-2017 MISO primary reliability auction and the 2019-2020 PJM capacityauction. Exelon also hoped to provide Illinois policymakers with additionaltime to consider reforms and for MISO to consider market design changes toensure long-term power system reliability in southern Illinois.

WhileClinton has cleared the MISO primary reliability auction, the resulting capacityprice is insufficient to cover cash operating costs and a risk-adjusted rate ofreturn to shareholders, Exelon said.

Theresults of the 2019-2020 PJM capacity auction will be available on May 24.