Honestly, threatening to shutdown early due to financial problem. I find it implausible all these equipment problems aren't coming from plant budget problems.
Any scram or LOOP with big equipment problems always puts a tremendous burden on the control room people. Safety is a scram or LOOP without equipment problems.
So here we sit, as example with recent Pilgrim, River Bend and Waterford plant scams and LOOPs with equipment breakdowns and bad employee responses...I think this all is a result of profound industry financial problem.
Calvert Cliffs nuclear plant at risk for ‘early retirement,’ report says
By Christopher GoinsChris@marylandreporter.com
Calvert Cliffs nuclear power plant on the Chesapeake Bay in Lusby (photo by NRCGov on Flickr)
Calvert Cliffs Nuclear Power Plant was listed as one of almost 40 nuclear reactors across the U.S. that is at risk of closing early, according to a new report from the Institute for Energy and the Environment at Vermont Law School.
The lone commercial nuclear power plant in Maryland might be on its way to early retirement for primarily economic reasons, the report’s author said. No dates were given for any reactors on the list and the author insists he’s not making predictions.
A spokeswoman for Constellation Energy Nuclear Group, the owner of Calvert Cliffs, said in response to the report that there are no plans to retire the plant early. The company brags on its website that the plant got a 20-year extension of its license in 2000 after replacing the steam generators.
“It usually takes a precipitator to create the crisis,” said Mark Cooper, a senior fellow for economic analysis at the Vermont school’s energy institute. “Calvert Cliffs (reactors) have had some history of liability issues or safety issues and outages issues. It’s one of these reactors where the economic context is not very bright,” said Cooper. “And then the question is does something come along to put it off the edge?”
NRC Sends Special Inspection Team to Calvert Cliffs Nuclear Plant
The Nuclear Regulatory Commission has begun a special inspection at the Calvert Cliffs nuclear power plant to review issues during the unplanned shutdown of both reactors on April 7. The plant, which is operated by Exelon, is located in Lusby, Md.
Calvert Cliffs, like all nuclear power plants, transmits power to the grid but also receives power back for operational purposes. A grid disturbance due the failure of a transmission line in Southern Maryland on April 7th caused both Calvert Cliffs reactors to automatically shut down as designed.
Following the grid disturbance, one of Unit 2’s emergency diesel generators (which provide power to safety systems when off-site power is lost) started, but tripped after 11 seconds. This same diesel generator failed to start in 2010 after a loss of off-site power. In addition, one of three saltwater pumps on Unit 2 failed to automatically restart when power switched to the emergency diesel generators. Per procedure, operators manually started the pump, which provides cooling water to certain plant equipment.
“While there was no impact on public health and safety, the issues with the emergency diesel generator and the saltwater pump warrant a closer look,” said Dan Dorman, NRC Region I Administrator.
The three-member team that arrived on-site today is tasked with developing a sequence of events; reviewing and assessing equipment response to the event; reviewing operator performance; and assessing the effectiveness of Exelon’s response to this event.
From the 2010 NRC AIT inspection: Run to failure philosophy on DG Relay
An inspection report documenting the team’s findings will be issued within 45 days of the end of the inspection.
Preliminary White: The NRC identified an apparent violation of Technical Specification
5.4.1 for the failure of Constellation to establish, implement, and maintain preventive maintenance requirements associated with safety related relays. The team identified that Constellation did not implement a performance monitoring program specified by the licensee in Engineering Service Package (ES2001 00067) in lieu of a previously established (in 1987) 1 O-year service life replacement PM requirement for the 28 EDG T3A time delay relay. As a consequence, the 26 EDG failed to run following a demand start signal on February 18, 2010. Following identification of the failed T3A relay, it was replaced and the 28 EDG was satisfactorily tested and returned to service. In addition, time delay relays used in the 1 Band 2A EDG protective circuits, that also exceeded the vendor recommended 1 O-year service life, were replaced. Constellation entered this issue, including the evaluation of extent-of-condition, into the corrective action program.
Rain Reboots At Calvert Cliff
During a winter storm on January 21, 2014, the Unit 2 reactor at the Calvert Cliffs nuclear plant in Maryland automatically shut down from full power. That event should not have cascaded to cause the Unit 1 reactor to also shut down, but it did.
At 9:25 pm on January 21, 2014, both of the pressurized water reactors (PWRs) at Calvert Cliffs were operating at full power. In PWRs, the heat produced by atoms splitting in the reactor core warms water to over 500°F. High pressure keeps this water from boiling as it leaves the reactor vessel and flows through tubes within the steam generator. Heat conducted through the thin metal walls of the tubes boils water. The pressurized water exits the steam generator and returns to the reactor vessel to be reheated. Steam flows from the steam generators through a turbine to generate electricity.
When a reactor is operating at steady state, the energy produced by the reactor core is balanced by the energy carried away in the steam leaving the steam generators.
Our Takaway
Weather caused water intrusion that shorted an electrical circuit, tripping one reactor. A design flaw allowed a ripple effect that tripped a second reactor at the plant.
It happened on January 21, 2014, as described above. It also happened on February 18, 2010 as described in UCS’s first annual report on the NRC and nuclear plant safety.
Each time it happened, the NRC dispatched a special inspection team to investigate. The NRC’s SIT for the 2010 happening found that the owner violated federal regulations by failing to properly correct conditions revealed by water intrusion events in August 2009 and July 2008.
The NRC’s SIT for the 2014 event found no federal regulations to have been violated. Apparently not even the one violated in 2010 due to recurring water intrusion events and inadequate fixes although this one also involved water intrusion.
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