How to refuel nuclear power plants during a pandemic?

Every spring, nearly 1,000 experts from across the United States move down to the Palo Verde Nuclear Power Station near Phoenix, Arizona, to refuel one of the three major nuclear reactors. As the largest power plant in the United States, Palo Verde provides electric power to over 4 million Southwestern residents. The process was inherently labor-intensive and took months to complete, so the reactor experts had to redraw the refueling plan during the pandemic.

It is expected that the Palo Verde nuclear power facility will receive new fuel in early April (the exact time is kept secret), but the preparation process has started months ago. The uranium (uranium) fuel began shipping to the nuclear reactor last fall, using a pickup truck that caught little attention. On the wagon are bundles weighing half a ton of 3.6-meter-high and 15-centimeter uranium rods.

This special shipment arrived at the power plant just before the SARS-CoV-2 virus began to spread. The biggest difference between the pre and post-season refueling plan is the size of operation. ' We have reduced our workload to a level sufficient to maintain operations for the next 18 months without affecting the plant's production capacity ,' said Greg Cameron, one of the directors of the nuclear power plant. by Palo Verde, said.

All three reactors are housed in concrete chambers, almost independently from the rest. This allows the plant to maintain an energy flow of up to 4 million people even when a reactor needs refueling. Every year and a half, the furnace will need to refill uranium and replace about 1/3 of its old reactor core.

It is possible to compare the refueling of the furnace with playing Jenga underwater. The oldest used uranium rods were extracted and placed in a storage tank, soaked for several years to cool before they were delivered to storage. Because the amount of energy that a uranium bar produces decreases over time, the amount of fuel left in the reactor is rubbed to regulate the heat, before the specialist can put in the new uranium bar.

The whole process is done by a giant gripper, similar to the device you see in the stuffed animal picker. They ensure uranium rods do not leave the water, preventing radiation from escaping and overheating the fuel rods.

Refueling the nuclear reactor takes nearly a month, requiring the help of hundreds of electrical specialists, welders and many other nuclear experts. However, there are still side jobs that can be cut, such as upgrading the reactor or monitoring work that can only be done when the reactor is turned off. During this pandemic, maintenance of the furnace will be at a minimum, sufficient for the oven to operate safely until the next refueling, Fall 2021.

In addition to halving the number of workers needed in the refueling phase, Palo Verde's nuclear power plant steering committee also left most of its staff working remotely, leaving only the operator room operator and the operators. other essential labor. In the yard, health professionals carefully examine the people in and out of the reactor area.

Not only Palo Verde, many other nuclear reactors in the United States also have a refueling schedule before June, and must apply similar measures to reduce personnel. Refueling and changing the plan to respond to a pandemic is of utmost importance at this time, when people need a more stable grid than ever.