BERWICK —Talen Energy has notified the U.S. Nuclear Regulatory Commission (NRC) that both units at the Susquehanna Nuclear Power Plant are now in compliance with a post-Fukushima order.
The 2011 Fukushima accident in Japan, which followed an earthquake and tsunami, disabled the plants’ ability to cool their reactor cores, causing heat and pressure to build within the concrete containment buildings that surround the reactors.
This buildup eventually damaged the buildings and made it easier for radioactive material to reach the environment.
The NRC issued an order on March 12, 2012, requiring all U.S. nuclear power plants with the Fukushima-style containment design to install what are known as reliable hardened containment (building) vents. It applies to the owners of boiling-water Mark 1 and 2 reactors; Susquehanna is home to Mark 2 reactors.
The containment structures at the plant house the reactors. For each plant, the company had to install a hardened vent from the plant’s dry well — the enclosed area around the reactor, and from the wet well — the large reservoir of cooling water at the base of the reactor building.
This not only helps preserve the integrity of the containment building, but can also help delay reactor core damage or melting.
After issuing the order, additional NRC evaluations examined the benefits of venting after reactor core damage occurs.
In June 2013, the NRC modified the order to ensure those vents will remain functional in the conditions following reactor core damage.
The NRC considered revising its regulations through the rule-making process to include strategies for filtering or otherwise confining radioactive material that gets released as a reactor core is damaged.
In August 2015, the Commission directed the staff not to proceed further with the rule-making.
Now that Talen has notified the NRC of the installation of the vents and associated actions, including training for operators who would use them, the agency’s staff will need to complete reviews of the changes.
Talen Energy is one of the largest independent power producers in the United States and the company purchased the Susquehanna Nuclear Power Plant from PPL April 2015. NRC spokesman Neil Sheehan said Talen was subsequently acquired by Riverstone Holdings, a separate license transfer approved in November 2016.
Reach Bill O’Boyle at 570-991-6118 or on Twitter @TLBillOBoyle.