Following a two-and-a-half year shutdown, Omaha Public Power District (OPPD) is ready to heat up Fort Calhoun’s reactor coolant system to inspect for any leaks. Heat-up is not the same as restarting the plant. The plant has been shut down since April 2011 for a refueling outage. The outage was extended due to historic Missouri River flooding followed by an electrical fire and other restart complications.
Fort Calhoun Station is heating up the reactor coolant system to ensure that the pipes carrying high pressure water or steam do not have leaks. Rather than heating up the reactor using the fission process, OPPD will use the reactor coolant pumps to heat up water and get steam flowing through the system. NRC inspectors are on site to observe licensee activities as well as perform independent inspections to ensure there are no leaks.
In early October, OPPD submitted a license amendment request seeking NRC permission to use a different methodology to evaluate high-pressure pipe breaks. OPPD has to demonstrate that if a high pressure pipe ruptures, that it would not negatively impact nearby equipment.
On Oct. 25, after reviewing public comments and additional information provided by the licensee, NRC approved this license amendment. OPPD did plant modifications and has performed calculations that show a potential pipe rupture will not affect nearby equipment. NRC inspectors are independently verifying the licensee’s analysis and modifications.
In addition, the staff has finalized its review of OPPD’s request to be exempt from the NRC’s fatigue rule which sets work hour limits in support of plant heat-up activities. The NRC’s fatigue rule puts limits on certain workers’ weekly hours to protect against fatigue. For example, during a refueling outage, a worker is allowed to work up to 72 hours every week versus an average of 54 hours over six weeks.
Before the NRC issued the exemption, the staff ensured that workers will have sufficient time to rest prior to working additional hours in support of the heat-up activities.
In addition, the NRC is continuing independent review of the remaining restart checklist items.
Next steps include preparations for the next public meeting whereby staff will update the public on NRC’s oversight status. No decision about restart will be made at that meeting.
U.S. NRC Blog 