But the Defense Department's own Explosives Safety Board quietly refused to give the Navy outright permission to build it. The Navy is building it anyway, now months into construction, giving itself approval by using an uncommon maneuver.
To be clear, the concern is not about a nuclear explosion. But the Safety Board found an unacceptable risk because the new wharf is adjacent to an existing wharf already handling nuclear missiles each containing enormous explosive power from volatile rocket fuel.
The Trident nuclear submarine is an awesome, complex machine. The Trident fleet carries about half the U.S. thermonuclear arsenal, up to 24 missiles in each atomic-powered sub with nearly 100 warheads.
At the Bangor submarine base on Hood Canal, they're serviced at several docks that can be seen in satellite images on common internet map sites.
Heavily censored and rarely seen navy documents obtained by the KOMO 4 Problem Solvers show massive cylinders that carry nuclear missiles being safely loaded and unloaded on subs during maintenance under a protective roof inside the existing explosives handling wharf. The Navy says as D-5 missiles age, upgrades extend their lives.
To handle that added work, construction is already underway on the second wharf so nuclear missiles from two subs could handled side by side at the same time. Permission to build that second wharf comes from the Department of Defense Explosives Safety Board in Alexandria, Virginia created solely to prevent military disasters.
The Board flat out rejected the second wharf, according to court documents, in part, because the Navy would not study the risk of a chain reaction explosion while loading two subs at two adjacent wharfs.
The Navy privately fired back.
"There are no new increased risks," said a Navy memo, that the Safety Board hasn't previously approved at other bases for "three decades."
The sub base is shrouded in secrecy, but activists think the risks to the public should be publicly discussed.
"I think a study would find that a detonation at one wharf would cause a detonation at the second wharf," said anti-nuclear activist Glen Milner.
His group "Ground Zero" filed a lawsuit hoping to stop construction. As part of the lawsuit, the Navy released documents that reveal what Milner calls this "raging debate" within the military.
One heavily redacted memo, signed by Assistant Secretary of the Navy Jackalyne Pfannenstiel, gives itself permission using a legal method called "secretarial certification," "accepting the risk," "permitting construction" of the wharf.
In other words, if there's a calamity, the Navy takes the blame.
"I would say, the greater the danger to the public," Milner said, "the less likely the navy is going to inform the public of that danger."
The Explosives Safety Board did not return inquiries from the Problem Solvers. And Navy brass at Bangor declined comment citing the on-going lawsuit.
It's important to remember the issue is not about nuclear explosions. But the equivalent explosive power in the rocket fuel inside each missile is 155,000 pounds of TNT. If both full subs explode, the equivalent power is 7.44 million pounds of TNT.
Video purporting to show the power of just one less potent, outdated Trident missile being destroyed sends overpowering shock waves across a wide expanse of desert.
Remember, there can be 24 in each sub. And 85% of the weight of each missile is highly explosive fuel, according to the Bulletin of the Atomic Scientists, a nuclear watchdog group.
A Navy map acknowledges that risk. It identifies a large danger zone around the wharf, should an explosion in one rocket ignite all the others on just one sub. Critics are suspicious because the danger zone goes right to the edge of the Bangor base whose boundaries were drawn years before the explosive power of the missiles were even designed.
The lawsuit claims "the Navy concealed known dangers" about a second wharf, which the Navy denies in court papers.
Milner believes the Navy lied.
"Oh, of course they did," he said. "I mean, they told the public all along that there's no new risk here. What they've done is they've double the amount of explosives. And they've doubled the number of times that missiles are being handled."
The Navy has said its 30-year safety record at Bangor is top notch.
Milner acknowledges the chance of one exploding missile igniting 47 others.
"I think that's true. But every time it's handled, the greater the likelihood of an accident."
While this is not about a nuclear detonation, a mishandled missile that explodes could release radioactive plutonium, says Ground Zero, potentially reaching population centers - whichever way the wind is blowing.
The new explosives handling wharf will cost $715 million and be finished in three years.