The Tennessee Valley Authority has asked the Nuclear Regulatory Commission (NRC) for a license amendment to allow an extended power uprate (EPU) for the three nuclear power reactors at Brown Ferry Nuclear Plant. This would amend its already-licensed steady-state reactor core levels and allow a power level increase of approximately 20 percent for all three units, according to an environmental group that is opposed.
BEST/MATRR, a Scottsboro-based chapter of Blue Ridge Environmental Defense League, alleges that TVA "has presented analyses that under-predicts the reaction of zirconium and steam that would occur in a loss-of-coolant accident at higher temperatures."
The organization is asking NRC to deny the TVA request since granting it "increases the safety risk to the public and employees. "
The group said, " The request comes despite questions about when and at what temperatures zirconium melting of fuel rod cladding occurs that will cause steam and hydrogen buildup* much as was seen in the Fukushima Daiichi meltdowns of 3 reactors in 2011. Actual tests showed that computer models underestimated the temperature levels. BEST/MATRR contends that allowing implementation of this amendment greatly increases the risk of a radioactive accident with a hydrogen explosion and also forces an increase in daily radionuclide venting to the air outside the reactor’s containment building."
Garry Morgan of BEST/MATRR said, “Zircaloy, a zirconium alloy, composes the thin cladding around the fuel rods holding the fissionable uranium. NRC should seek to reduce, not increase, the risk of loss of coolant that will melt the fuel rods leading to meltdown and released radiation.
“The extra strain using this high burnup fuel is unnecessary and unacceptable given the safety history of this type of Westinghouse reactors at Browns Ferry.”
He said the Mark II Westinghouse reactor "is like the ones at Fukushima that melted down in 2011."