Nuclear ban monitoring expands since N.Korea test

VIENNA (Reuters) - Nuclear test-ban monitoring has expanded its global reach since last year when North Korea detonated an atomic device, a senior international official said on Tuesday.

The reclusive Stalinist state marked the first anniversary of the test as "a great miracle" for all Koreans. The detonation sparked worldwide alarm and a North Korean deal with five powers to disable nuclear facilities in exchange for major energy aid.

Around 20 seismic stations set up under the Comprehensive Nuclear Test Ban Treaty (CNTBT) detected the North Korean blast, and a station in northern Canada equipped with special radionuclide noble gas-monitoring technology verified its nuclear nature.

"Although completed only partially and operating in test mode, the system proved its worth and its future potential," the executive secretary of the Vienna-based CTBT organization said in a statement.

"The North Korean test, as disconcerting as it was, turned out to be a validation of the verification system. This bodes well for the CTBT's verifiability," Tibor Toth said.

The number of stations able to pinpoint nuclear test blasts underground, undersea or in the air had since grown by almost 20 percent to 213, with an overall goal of 337.

"(The test) refocused the attention of the international community on the relevance of the CTBT as a key disarmament and non-proliferation instrument," said Toth.

However, the 1996 treaty has not yet taken legal force.

While the accord has been ratified by 140 countries in all, 10 more with nuclear capabilities -- including the United States and China -- must follow suit to transform the CTBT from an informal moratorium into a binding document.