We are pleased to announce that Holtec’s engineers have succeeded in designing SMR-160 into a “walk-away” safe nuclear power plant, which means that if a calamity were to strike – similar to the tsunami that devastated Fukushima ̶ the plant will passively (without human intervention) switch to and remain in a safe shutdown and cooled configuration for an unlimited period. Faced with an extenuating event, the reactor will automatically shut down and all of the plant’s fuel – both in the reactor and the spent fuel pool ̶ will remain in a safely cooled state without the need for electric power. Unlike its peers, which all have limited duration coping periods, requiring water make-up after a specific number of hours or days, the SMR-160 plant is designed to remain passively cooled indefinitely, without requiring any operator activity.
Postulating an accident leading to a sudden breach in a pressurized reactor coolant line (known as LOCA in nuclear parlance), a break in a main steam line, or a sudden station blackout, the SMR-160 plant would readily and passively respond to any of these events without any loss of its cooling capacity or risk of release radioactivity or any other adverse effect on the surrounding environment.
As a first line of defense, SMR-160’s designers have eliminated the single largest plant vulnerability ̶ large piping ̶ entirely from the reactor coolant system and containment building through creative designs. The largest high-pressure pipe in the plant is eight inches in diameter!
A second transformative design innovation leverages gravity combined with conduction heat transfer ̶ two unfailingly reliable phenomena in nature – to facilitate all necessary heat removal from the plant’s nuclear fuel, and subsequent expulsion of heat to the atmosphere. The result is a gravity-driven heat rejection system that keeps the nuclear fuel and the containment and its internals cool for as long as necessary.
Patents on the innovative design features that underlie the inherent safety and stability of the SMR-160 plant have been filed with the USPTO.
“Unconditional walk-away safety, affordable capital, and operational costs are mandatory elements of a viable nuclear power product for the new energy generation landscape. Making SMR-160 a reliable steward of the environment has been central to our development effort, and I’m pleased to say we’ve successfully achieved our mission”, says Tom Marcille, Holtec’s VP of Reactor Technologies.