By Frank Mand
Feb. 9, 2015
PLYMOUTH – It hasn’t been a good two weeks for Pilgrim Nuclear Power Station, but Wednesday the plant announced the successful and uneventful completion of its first “dry fuel program” – the transfer of 204 spent fuel assemblies from the pool inside the reactor building to three dry cask storage units.
According to Lauren Burm, senior communication specialist for Entergy at Pilgrim Station, the third and final cask for this program was safely placed on the pad Feb. 4.
The transfer process actually takes place within the reactor, more than 100 feet above the ground floor and, once an individual cask is filled, the cask is lowered to the ground and maneuvered out onto a concrete pad just north of the reactor building.
The three casks that make up a program – each of which hold 68 assemblies – are located in what Burm called “a highly secure fenced in area located 23 feet above sea level” and checked daily by Pilgrim staff as well as monitored by plant security around the clock.
Pilgrim’s dry cask program was approved and monitored by the NRC. The storage containers are NRC licensed and tested, designed to withstand a variety of extreme scenarios, ranging from tornadoes, accidents and severe weather to earthquakes and terrorist attacks.
Burm said that Pilgrim anticipates loading three additional casks every two years, which will allow the continued use of the pool inside the reactor for the foreseeable future.
Without offloading these 204 spent fuel assemblies every other year the pool would soon reach its maximum capacity. Originally designed for less than 1,000 spent fuel assembles – with the expectation that the federal government would develop a permanent repository for nuclear waste – the pool at Pilgrim now holds more than 3,000.
Critics say the main benefit of dry cask storage for a plant like Pilgrim is that it gets the assemblies out of the pool inside the reactor building. But Entergy’s plan is to remove fuel assemblies in the pool during non-refueling years only (every other year).
Since the company will add another 150 assemblies to the pool during every refueling year (fuel assemblies must spend at least five years in the pool to cool down), the net reduction in assemblies stored within the pool will be approximately 50 fuel rod assemblies every two years.
By the time the plant’s license expires, the assemblies in the pool will only have been reduced by 500, leaving 2,700 still in the pool in 2032.
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