First deployment of a U.S. nuclear-powered aircraft carrier in Japan

by Koji Yamamoto, Senior Staff Writer

The USS George Washington, a U.S. Navy Nimitz-class nuclear-powered aircraft carrier, arrived at the Navy’s base in Yokosuka, Kanagawa Prefecture, on September 25. This is the first time a nuclear-powered vessel has made its home port in Japan. The carrier-based aircraft are scheduled to be relocated to the U.S. Marine Corps Air Station in Iwakuni by 2014, which will have a major impact on the base there. This report examines the differences between the George Washington and conventionally powered carriers that have been stationed in Japan in the past as well as the ship’s safety and its future operations in Japan.

Features: Details remain a military secret

On the morning of September 25 a file folder was distributed to the members of the news media who were awaiting the arrival in Yokosuka of the George Washington. Along with greetings from Donald Winter, Secretary of the Navy, and Thomas Schieffer, U.S. ambassador to Japan, there was a pamphlet describing the ship.

It included facts such as where the ship was built, the length of the flight deck and the number of screws. The only references to the fact that it is a nuclear-powered carrier were the descriptions of the ship’s class (nuclear-powered aircraft carrier) and its method of propulsion (two nuclear reactors), indicating that more than 50 years after the 1955 launch of the USS Nautilus, the U.S. Navy’s first nuclear submarine, details remain a military secret.

For the most part, the differences between conventional carriers and nuclear-powered carriers were simply summed up in the fact that the latter have two nuclear reactors.

Because a nuclear-powered carrier seldom needs to refuel, it does not need large fuel tanks. The space that is freed up as a result can be used to carry fuel for the Aegis and other destroyers that accompany the ship as part of the carrier strike group and fuel for the carrier-based aircraft as well as missiles, bombs and other munitions.

On the home page for the U.S. naval forces in Japan, their commander, Rear Admiral James Kelly, said of the George Washington, “A Nimitz-class carrier can sustain crisis or combat operations for at least twice as long as an oil fuel-powered carrier due to its increased capacity for aviation fuel and weapons storage.”

At first glance the nuclear reactors seemingly have nothing to do with the takeoff and landing of aircraft from the flight deck, but in fact they have a major impact on those operations.

Steam is used when an aircraft is launched using the catapult and when the brake on the arresting wire is applied when an aircraft is caught by its tailhook upon landing. On conventional carriers, steam is produced by boilers that burn fuel, but on a nuclear-powered carrier plenty of steam can be obtained from the fission reaction. As a result, according to the pamphlet that was distributed, two aircraft can be launched and one can land every 37 seconds during the day, while at night this can be done every 60 seconds.

This feature of nuclear power makes it militarily the optimal energy source for submarines, which must remain underwater for long periods of time, as well as aircraft carriers. For this reason the U.S. Navy currently has more than 80 nuclear-powered ships, including 10 aircraft carriers.

Safety: Radiation leaks generate protests

With the deployment of the first nuclear-powered ship to Japan, safety has become the biggest concern of local residents and others.

The U.S. government is well aware that as the only country to have suffered atomic bombings Japan is touchy with regard to nuclear-powered vessels. As a result, in 2006, prior to the deployment of the George Washington to Yokosuka, the U.S. government issued a fact sheet on the safety of its nuclear-powered warships.

It stressed the safety of the ships, including the following points: 1) “The hull is a high-integrity structure designed to withstand significant battle damage. Reactor compartments are located within the central, most protected section of the ship.” 2) “The average power level of reactors on nuclear-powered aircraft carriers over the life of the ship is less than 15% of their full rated power, and reactors are normally shut down shortly after mooring.” 3) “U.S. nuclear powered warships have safely operated for more than 50 years without experiencing any reactor accident or any release of radioactivity that hurt human health or had an adverse effect on marine life.”

However, in early August, prior to the deployment of the George Washington, it was revealed that over a period of two years water with trace amounts of radioactivity had been leaking from the USS Houston, a nuclear submarine that made port calls in Yokosuka, Sasebo in Nagasaki Prefecture and White Beach in Uruma, Okinawa, during that time. Though only trace amounts, it was the first time the U.S. Navy disclosed the leakage of radiation in Japan, and the local governments affected lodged strong protests. This cast a shadow on the ship’s safety, which should be ironclad, so the efforts of the U.S. government and the navy to reassure the public were seemingly for naught.

It was also disclosed that the May 22 onboard fire that delayed the deployment of the George Washington to Yokosuka by one month was caused by smoking in violation of the ship’s rules. This exacerbated concerns about the “quality” of the ship’s crew.

In anticipation of the deployment of the George Washington, Kanagawa Prefecture and the City of Yokosuka increased from four to 10 the number of radiation monitoring posts near the base. Under the basic premise that the safety of local residents must be assured, they have undertaken strict monitoring for radiation leaks.

Operations: Situation in the Far East is key

With the deployment of the nuclear-powered carrier in Japan, its domestic operations have become the focus of attention. The USS Kitty Hawk, which was stationed in Yokosuka prior to the George Washington, made a friendly port call in Muroran in Hokkaido in October 2007 for refueling as well as rest for the crew and goodwill interactions with the local people. Will the George Washington make similar port calls to civilian ports?

With regard to this point, in an earlier diplomatic memorandum, the U.S. government clearly stated that the port calls of nuclear-powered warships are limited to Yokosuka, Sasebo and White Beach.

After the ceremony welcoming the George Washington to Yokosuka, Rear Admiral Richard B. Wren, commander of the Carrier Strike Group 5, held a press conference. When asked about the possibility of port calls at civilian ports, he simply said the George Washington might call at ports that had previously been visited by nuclear-powered vessels.

However it must be remembered that this memorandum was written in 1964, long before the deployment of the nuclear-powered carrier. Furthermore, this permanent deployment is completely different from the brief port calls that have been made since nuclear submarines first began making port calls in Japan in 1964, which were intended to offer the crew rest and to re-supply the ship.

Will this rule limiting the aircraft carrier, which is essential for the U.S. Navy’s mobilization force, to three ports continue to be adhered to even in the event of an emergency just because of the difference in its method of propulsion? And will preliminary inspections be made in preparation for such an emergency? There is growing skepticism in this regard.

After the landing base for the carrier’s aircraft is changed from the Navy’s Atsugi base in Kanagawa Prefecture to the Marine Corps Air Station in Iwakuni, many personnel working with the carrier-borne aircraft squadron will have to travel whenever the ship leaves or enters port.

Even if the situation changes, can the Japanese government and the U.S. naval forces in Japan state with certainty that the memorandum issued more than 40 years ago will still be complied with? If tensions should heighten in the Far East, it is possible the George Washington may expand its operations to include at the very least the Japan Sea side of the Chugoku Region and the coastal waters relatively near the base in Iwakuni.

(Originally published on October 19, 2008)

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