Exelon officials said they have begun taking necessary steps to shut down the two plants. Those will include notifying the Nuclear Regulatory Commission of the shutdowns within the next 30 days, terminating capital investment projects required for long-term operation of the plants and canceling fuel purchases and outage planning.

Exelon left open the slim possibility Thursday the closure decision could be reversed if talks move in a positive direction.

“The decision can be reversed but only in narrow circumstances, and week by week, a reversal becomes more and more difficult," said spokesman Brett Nauman. "As we have stated previously, legislation would have to be sufficient from an economic standpoint to warrant continued operation of the plant and in a time frame that would allow a reversal.”

Nauman said the company will “continue working with stakeholders to reach a viable path forward for these important assets as long as possible while staying on the planned closure timeline."

Crane's email to employees with the news on Thursday, obtained by The Associated Press, included a plea that workers call a listed telephone line and record a message for Gov. Bruce Rauner and lawmakers in favor of the legislation.