Clinton Power Station operators manually took the unit offline Friday morning, after observing low hydraulic pressure on the control system that regulates the speed on the main turbine.
The main turbine is the machine that drives the generator, which produces electricity at the station and is on the non-nuclear side of the plant.
Clinton operators are looking into the cause of the low pressure and will make any necessary repairs prior to returning the unit to service.
The unit shutdown will not affect electrical service to customers.
Clinton Power Station is about six miles east of Clinton, IL. The plant produces 1,078 megawatts, enough electricity for about one million homes.
The power station began service on April 24, 1987.
The station has a single General Electric generation II boiling water reactor. The reactor design is a BWR-6 with a Mark III containment structure. The present reactor operating license will expire September 29, 2026.
After less than a decade of operation, the plant’s original owner, Illinois Power, had to close it in 1996 following technical problems. The company decided it was not economical to own and operate only one nuclear generating station in the deregulated market, so they kept it shut down while looking for an interested buyer.
Exelon Corp. bought it for $40 million, with the purchase including the fuel in the reactor vessel and responsibility of all the radioactive waste in the spent fuel storage pool.