Đôi nét về CNQP Nhật Bản

Đôi nét về công nghệ quốc phòng Nhật Bản

Âm thầm, lặng lẽ, không phô trương, nhưng công nghiệp quốc phòng Nhật Bản được xem là hàng đầu trong khu vực châu Á.

 Trước và trong chiến tranh thế giới thứ 1 và thứ 2, công nghiệp quốc phòng Nhật Bản được đánh giá thuộc loại hàng đầu thế giới và ngang ngửa với Mỹ.


Khi đó, các loại máy bay chiến đấu như Aichi-D3A, A6M Reisen (Zero), Ki-45... và đặc biệt, thiết giáp hạm Yamoto được xem là chiến hạm hàng đầu thế giới lúc đó.

19/03 N-mishap team ready to depart from U.S.

Satoshi Ogawa / Yomiuri Shimbun Correspondent

WASHINGTON--The U.S. Defense Department is preparing to dispatch an expert team trained to operate in areas contaminated with radiation, should the situation deteriorate at the Fukushima No. 1 nuclear power plant, it was learned Thursday.

Adm. Robert Willard, commander of the U.S. Pacific Command, told a press conference that 450 members of the team were "making preparations" for a dispatch order to Japan.

Willard also said another team comprising nine nuclear experts left for Japan on Thursday as an advance group. This group is trained to deal with terrorist activities involving nuclear arms and related problems on the U.S. mainland, he said.

According to the Pentagon Web site, the advance group is called the damage evaluation and management squad and is meant to be mobilized first after attacks or accidents involving chemical or biological agents, or radioactive or other nuclear substances.

He said the advance squad is capable of managing radiation and will be ready to provide a range of assistance if requested. It will assess what U.S. military forces would be necessary if the dangerous situation at the nuclear plant does not improve or if there is a massive accident that disperses high-level radiation.

The squad also can assist with search and rescue operations, and support decontamination, medical services, aviation, telecommunication and logistic activities, the Web site says.

However, it has no expert knowledge about the functioning of nuclear reactors.

The team also will advise Japan's Self-Defense Forces at the locations of radiation leaks at the Fukushima nuclear power facility, Willard said.

Willard said he will visit Japan from Saturday to consult with SDF officers about steps to prevent the crisis from deteriorating further.

(Mar. 19, 2011)

22/03 Reactor cooling efforts continue

The Daily Yomiuri

Tokyo Electric Power Co. stepped up efforts Monday to restore electricity at a reactor at a quake-hit nuclear power plant while firefighters and Self-Defense Forces personnel continued spraying water to cool down two other overheating reactors at the complex.

But in a worrying development, gray smoke was seen rising near the temporary fuel storage pool of the No. 3 reactor at the Fukushima No. 1 nuclear power plant at about 3:55 p.m. TEPCO immediately suspended all restoration work and ordered its workers to evacuate the site.

The Nuclear and Industrial Safety Agency said earlier in the afternoon the functions of the No. 2 reactor's central control room air conditioning system and some reactor instruments might be restored within the day.

A TEPCO inspection found that to supply electricity to the No. 2 reactor's central control room, some instruments, such as the backup water system motor and a power-supply unit, needed to be repaired or replaced.

It is expected to take several days to restore the reactor's cooling system, officials said.

The development came a day after TEPCO confirmed electricity had reached the switchboard-cum-transformer at the reactor's turbine building.

TEPCO workers also continued efforts to send electricity from the No. 2 reactor to the No. 1 reactor, and lay cables to the Nos. 3 and 4 reactors. However, work to lay cables to the Nos. 3 and 4 reactors was reportedly running into trouble because of debris from previous explosions and high radiation levels.

Electricity also reached the switchboard of the No. 5 reactor at about 11:30 a.m., and switched the reactor power source from an emergency generator to an outside power source about 90 minutes later, making it technically possible to send electricity to the No. 6 reactor, TEPCO officials said.

Electricity at the Nos. 5 and 6 reactors had been supplied by emergency diesel-powered generators.

At the Nos. 5 and 6 reactors, temperatures reportedly have stabilized at 100 C or lower. Water temperatures in the two reactors' nuclear fuel storage pools also declined to normal levels of 39.5 C and 32 C, respectively, as of 5 a.m. Monday, TEPCO said.

Experts warned the rain might temporarily raise radiation levels in the area because radioactive material that had floated in the air might fall to the ground.

3,700 tons of water sprayed

Meanwhile, a special squad of the Tokyo Fire Department and other firefighters blasted about 1,130 tons of water into the No. 3 reactor's nuclear fuel storage pool for about 6-1/2 hours until 4 a.m. Monday. It was the Tokyo firefighters' third spraying operation at the plant.

The combined amount of water blasted on the No. 3 reactor, including that sprayed by the SDF, reached 3,700 tons by Monday morning, officials said.

The SDF sprayed water on the fuel storage pool of the No. 4 reactor for about two hours starting at about 6:40 a.m. Monday.

The water-spraying operations to date likely have raised water levels in the nuclear fuel storage pools and decreased water temperatures, gradually lowering radiation levels from damaged nuclear fuel rods.

If workers are able to maintain the fuel storage pool water levels, the next focus would be to try to restore electricity from outside to the Nos. 1 to 3 reactors, so as to constantly cool the reactors using their own cooling systems.

Currently, workers are injecting pumped seawater into the reactor pressure vessels in each reactor core.

(Mar. 22, 2011)