LEAD: ADSF aircraft dispatched to check radioactivity in skies over Japan+

TOKYO, May 25 Kyodo -
The Defense Ministry dispatched aircraft Monday night to take air samples from
the sky over Japan to see if any radioactive material has been emitted into the
air following North Korea's claim that it conducted a second nuclear test, the
ministry said.

In the afternoon, Defense Minister Yasukazu Hamada called an emergency meeting
with senior officials of the ministry and the Self-Defense Forces to collate
information gathered on the North's declared nuclear test.
''Make sure you do what you should do as members of the Defense Ministry, such
as the analysis of information and the collection of dust in the air,'' Hamada
was quoted by Vice Defense Minister Kohei Masuda as telling the meeting.
Air Self-Defense Force T-4 training aircraft, equipped with a dust collector
that looks like an external fuel tank, were dispatched from the ASDF bases in
Aomori, Ibaraki and Fukuoka prefectures, the ministry said, adding that more
flights are expected in the coming days.
The samples, which will be gathered on specific flight routes 10 kilometers
above sea level, will be analyzed by a government-affiliated laboratory to see
if any radioactive material would be found that backs up Pyongyang's claim of
its second underground nuclear test, the ministry said.
T-4s were used on a similar mission last time the North conducted a nuclear
test in October 2006. No radioactive materials that suggested the test were
found then, according to the ministry.
Meanwhile, Masuda suggested that North Korea appeared to have followed through
on its threat late last month to take ''defensive measures'' unless the U.N.
Security Council apologizes for condemning its April 5 rocket launch, suspected
to be a cover for long-range ballistic missile testing.
''We need to carefully monitor and keep track of (North Korean) movements in
thinking about national security and the defense of our country,'' Masuda told
a news conference.
North Korea's official Korean Central News Agency said Monday that the country
''successfully conducted one more underground nuclear test'' and that the
results ''helped satisfactorily settle the scientific and technological
problems arising in further increasing the power of nuclear weapons.''
Pyongyang also test-fired three short-range missiles toward the Sea of Japan on
Monday, South Korean Defense Minister Lee Sang Hee said.
==Kyodo