Friday, May 25, 2007

US Navy Goes Nuclear

The fiscal year 2008 defense authorization bill (official text and its status) was passed by the House in mid-May 2007 on a vote of 58 to 0.

There are two very import issues in the bill.

First, it seeks to increase the DOD renewable energy purchases from the current level of 9% to at least 25% in 2025. I see that many people already jumped on that. No, it is not on renewable energy for mobility. It is renewable energy for DOD electricity need. So, to put headline like Pentagon goes green is unjustified. Pentagon only tries to go green by purchasing some of it electricity produced from renewables. If you buy your electricity from the grid is there any way to know whether the electricity powering your devices at home is generated from renewables or from coal?

Besides that the Bill talks about energy conservation but they all refer to electricity. That is why the text should have been worded as electricity conservation. How about energy efficiency? Well, the text talks about efficient light bulbs. Moreover, the Bill authorizes (or gives away) millions of dollars for energy conservation assistance or advise (so called energy projects and efforts). Good for private companies.

Second, the Bill suggests the US Navy go nuclear, which was the subject of my post in the first place.

More specifically, the House Committee requires that all new ship classes of submarines, aircraft carriers, cruisers, battleships, or other large surface combatants whose primary mission includes protection of carrier strike groups, expeditionary strike groups, and vessels comprising a sea base cruisers are built with integrated nuclear power systems, unless the Secretary of Defense determines it is not in the national interest to do so. (See the Section 1012 in the official text)

The term ‘‘integrated nuclear power system’’ means a ship engineering system that uses a naval nuclear reactor as its energy source and generates sufficient electric energy to provide power to the ship’s electrical loads, including its combat systems and propulsion motors.

Now, let me look at the very recent past on Navy going nuclear:

In a DefenseNews article (Taylor Urges Larger, Nuclear Fleet) in January 2007 the following was reported:

The future U.S. surface fleet should be bigger than it is today and it should be nuclear powered, according to Rep. Gene Taylor, D-Miss., the new chair of the U.S. House Armed Services Committee (HASC) seapower and expeditionary forces subcommittee.
While ground vehicles and aircraft will always rely on conventional power sources, surface vessels are big enough to support nuclear reactors, Taylor said.

Taylor urged that the future surface fleet be nuclear-powered, in part, because of America’s dependence on foreign oil. He also noted the vulnerability of conventionally-powered surface fleet in a time of war, while American submarines and aircraft carriers have nearly unlimited endurance due to their nuclear propulsion.

The best background on Navy Nuclear program is provided (as usual) by Ronald O’Rourke in a CRS paper on April 2, 2007 (Navy Nuclear-Powered Surface Ships: Background, Issues, and Options for Congress)

Here are some important parts of his report:

There has been increasing interest in expanding the use of nuclear power to a wider array of Navy surface ships, especially the Navy’s planned CG(X) cruiser. The Navy wants to procure the first CG(X) in FY2011, and is currently studying design options for the ship, including the use of nuclear power.

In assessing whether the CG(X) or other future Navy surface ships should be nuclear-powered, Congress may consider a number of issues, including cost, operational effectiveness, ship construction, ship maintenance and repair, crew training, ports calls and forward homeporting, and environmental impact.

Most military ships and large commercial ships are conventionally powered (oil), meaning that they burn a petroleum-based fuel, such as marine diesel, to generate power for propulsion and for operating shipboard equipment. Some military ships are nuclear-powered,[1] meaning that they use an on-board nuclear reactor to generate power for propulsion and shipboard equipment.

Nuclear Power for a Surface Combatant eliminates the need for the ship to periodically refuel during extended operations at sea, and hence overcome all the negative effects of refueling.

The Navy’s nuclear propulsion program began in 1948.[2] The Navy’s first nuclear-powered ship, the submarine Nautilus (SSN-571), was commissioned into service on September 30, 1954, and went to sea for the first time on January 17, 1955. The Navy’s first nuclear-powered surface ships, the cruiser Long Beach (CGN-9) and the aircraft carrier Enterprise (CVN-65), were commissioned into service on September 9, 1961, and November 25, 1961, respectively.

As of the end of FY2006, the Navy’s nuclear-powered fleet included all 73 of its submarines and 10 of its 11 aircraft carriers.[3] The Navy’s combat submarine force has been entirely nuclear powered since 1990. The planned retirement of the Navy’s last remaining conventionally powered aircraft carrier in 2008 is to give the Navy an all-nuclearpowered carrier force by 2008.

The Navy in the past built and operated nine nuclear-powered cruisers (CGNs).

The Navy’s planned 313-ship fleet calls for a total of 19 CG(X)s. The Navy has stated that it wants to equip the CG(X) with a powerful radar capable of supporting ballistic missile defense operations. The Navy has testified that this radar is to have a power output of 30 or 31 megawatts, which is several times the power output of the main radar on the Navy’s existing cruisers and destroyers. This suggests that in terms of power used for radar operations, the CG(X) might use substantially more energy over the course of its life than the Navy’s existing cruisers and destroyers. As discussed later in this report, a ship’s life-cycle energy use is a factor in evaluating the economic competitiveness of nuclear power compared to conventional power.

Since the two fuel cores for an aircraft carrier cost about $660 million in constant FY2007 dollars, the cost of a single fuel core for a CG(X) might be about $330 million in constant FY2007 dollars.

The newly calculated life-cycle cost break-even cost-ranges, which supercede the break-even cost figures from the 2005 NR quick look analysis, are as follows:

— $210 per barrel to $670 per barrel for a small surface combatant;
— $70 per barrel to $225 per barrel for a medium-size surface combatant; and
— $210 per barrel to $290 per barrel for an amphibious ship. In each case, the lower dollar figure is for a high ship operating tempo, and the higher dollar figure is for a low ship operating tempo.

At a crude oil cost of $74.15 per barrel (which was a market price at certain points in 2006), the life-cycle cost premium of nuclear power is:

— 17% to 37% for a small surface combatant;
— 0% to 10% for a medium sized surface combatant;
— 7% to 8% for an amphibious ship.

The Navy has stated a preference for basing the design of the CG(X) on the design of its new DDG-1000 class destroyer, which is a conventionally powered ship. The Navy estimates that follow-on DDG-1000 destroyers will cost an average of about $1.9 billion each to procure in constant FY2007 dollars.

Future Oil Prices. Views on potential future oil prices vary. Some supporters of using nuclear power for the CG(X) and other future Navy surface ships, such as Representatives Gene Taylor and Roscoe Bartlett, the chairman and ranking member, respectively, of the Seapower and Expeditionary Forces Subcommittee of the House Armed Services Committee, believe that oil in coming decades may become increasingly expensive, or that guaranteed access to oil may become more problematic, and that this is a central reason for making the CG(X) or other future Navy surface ships nuclear-powered.

I am not a nuclear engineer. The question that bothers me is the following. If a missile hits a nuclear powered surface ship what happens to the reactor? And how about the contamination?

[1] U.S. Navy nuclear-powered ships use pressurized water reactors (PWRs) that are fueled
with highly enriched uranium.
[2] The first director of Naval Reactors office was Admiral Hyman Rickover, who is often referred to as the father of the nuclear Navy.
[3] The Navy’s last remaining conventionally powered carrier is the Kitty Hawk (CV-63), which was procured in FY1956 and entered service in 1961. In 2008, it is scheduled to be retired and replaced by the new aircraft carrier George H. W. Bush (CVN-77), which was procured in 2001.

Tags: Nuclear, US Navy, Military Oil Consumption, Department of Defense




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