From the many studies I’ve read, the costs of conventional versus nuclear power tend to be a wash when all the pertinent factors are included. For that reason, ComNavOps is ambivalent on the issue. I have a slight leaning towards conventional power, not for any cost reasons but for the damage control aspects and repairability in battle. But, I digress …
The point of this post is not to settle the issue but to offer one semi-relevant data point.
One of the major costs for a nuclear carrier is the mid-life Refueling and Complex Overhaul (RCOH). Costs seem to run around several billion dollars, if the Navy is to be believed. Common sense, however, suggests that this kind of oft cited cost is not true. Unfortunately, we have no itemized breakdown of the refueling costs to look at. Remember that carrier refueling is always combined with a massive overhaul effort, the total of which is the cited cost but no one knows how much of the cost is direct nuclear refueling costs and this leads, inevitably to a large part of the ambiguity about nuclear refueling costs.
Well, here’s a related data point. It’s the SSBNs which also undergo a mid-life refueling overhaul (Engineered Refueling Overhaul – ERO). As an example, the USS Louisiana (SSBN-743) is currently at the start of a 2-1/2 year refueling overhaul at Puget Sound Naval Shipyard.
The project is expected to finish in 2022 and will take approximately 729,000 man-days to complete with a cost of around $400 million. (1)
Note that the $400M includes both conventional overhaul work and the nuclear refueling work. The non-nuclear refueling portion of the work – the overhaul portion – will include hull/tank preservation, a modernized reverse osmosis system, and modifications to accommodate female crew. Thus, the nuclear refueling costs are something less than $400M. The overhaul work does not seem terribly extensive or complex so I’d venture a guess that the nuclear portion of the costs is, perhaps, $300M.
That cost, $400M, is immensely less than the RCOH cost of multiple billions of dollars. Why the enormous cost discrepancy?
One major reason is the sheer scope of the overhaul work – work that has nothing to do with the nuclear refueling.
During the dry dock phase of the RCOH, George Washington underwent significant upgrades and repair work both inside and outside the ship. In addition to defueling and refueling its power plant, Newport News shipbuilders have re-preserved approximately 600 tanks and replaced thousands of valves, pumps and piping components.
On the outside, they performed major structural updates to the island, mast and antenna tower; upgraded all aircraft launch and recovery equipment; painted the ship’s hull, including sea chests and freeboard; updated the propeller shafts, and installed refurbished propellers.
During the next phase of the complex engineering and construction project, shipbuilders will finish up the overhaul and installation of the ship’s major components and test its electronics, combat and propulsion systems before the carrier is redelivered to the navy. This period also will be dedicated to improving the ship’s living areas, including crew living spaces, galleys and mess decks. (2)
It is obvious from that brief description of the non-nuclear overhaul work that the scope and, therefore, cost is enormous.
What is the split between overhaul and nuclear refueling cost for a carrier RCOH? Is it 50% each? Is it 90% nuclear? Is it 90% overhaul? Unfortunately, I’ve never seen even a crude breakdown of the cost split and that leads to the aforementioned arguments and suspect data.
On the surface of it, the SSBN ERO cost suggests that the actual nuclear refueling cost is not the major portion of the carrier RCOH and that the overhaul work is, instead, the major portion. I would go so far as to venture a guess that the overhaul cost is on the order of 70% of the total RCOH cost. If that’s even remotely correct, that drastically alters the financial arguments that are typically used to debate the nuclear power question.
Of course, a submarine ERO and a carrier RCOH are not directly comparable, even for the nuclear refueling portion of the work. A carrier’s immense size means that the reactor is buried much deeper in the vessel and access is more difficult. A carrier presumably has larger reactors and two of them as opposed to the single reactor in a submarine. And so on. Presumably, those factors add to the nuclear refueling cost but how much they add to the cost is unknown. I would guess, perhaps, a 10%-20% premium?
The takeaway from the submarine ERO is that nuclear refueling costs are not inherently obscenely expensive which is the impression so many critics of nuclear power would have us believe.
As I said, this post makes no attempt to settle the nuclear versus conventional power debate. It only adds a related data point to help guide discussions.
(1)navaltoday.com website, “Ballistic missile submarine USS Louisiana docks for refueling overhaul”, 17-Sep-2019,https://navaltoday.com/2019/09/17/ballistic-missile-submarine-uss-louisiana-docks-for-refueling-overhaul/
(2)navaltoday.com website, “USS George Washington undocks during nuclear refueling overhaul”, 1-Oct-2019,https://navaltoday.com/2019/10/01/uss-george-washington-undocks-during-nuclear-refueling-overhaul/