Question: When did the north korean nuclear program start?

Disambiguated questions and answers:
context: No context provided
question: When did the Phase I of the North Korean nuclear program start?|In what year did the North Korean nuclear program start getting training for scientists?
short_answers: 1956
context: North Korea showed an interest in developing nuclear weapons since the 1950s. The nuclear program can be traced back to about 1962, when North Korea committed itself to what it called "all-fortressization", which was the beginning of the hyper-militarized North Korea of today. In 1963, North Korea asked the Soviet Union for help in developing nuclear weapons, but was refused. The Soviet Union agreed to help North Korea develop a peaceful nuclear energy program, including the training of nuclear scientists. Later, China, after its nuclear tests, similarly rejected North Korean requests for help with developing nuclear weapons.
question: When did the North Korean nuclear program start (with its "all-fortressization" initiative)?
short_answers: 1962
wikipage: North Korea and weapons of mass destruction
context: Soviet engineers took part in the construction of the Yongbyon Nuclear Scientific Research Center and began construction of an IRT-2000 research reactor in 1963, which became operational in 1965 and was upgraded to 8 MW in 1974. In 1979, North Korea began to build a second research reactor in Yongbyon, as well as an ore processing plant and a fuel rod fabrication plant.
question: When did North Korean start building a nuclear reactor?
short_answers: 1963
wikipage: North Korea and weapons of mass destruction
context: On October 9, 2006, North Korea demonstrated its nuclear capabilities with its first underground nuclear test, detonating a plutonium based device with an estimated yield of 0.2–1 kilotons. The test was conducted at Punggye-ri Nuclear Test Site in North Hamgyong Province, and U.S. intelligence officials later announced that analysis of radioactive debris in air samples collected a few days after the test confirmed that the blast had taken place. The UN Security Council condemned the test and announced the imposition of Resolution 1874.
question: When did the North Korean nuclear test start?
short_answers: 2006
October 9, 2006
wikipage: North Korea and weapons of mass destruction

Long-form answers:
knowledge: content: The North Korean nuclear program can roughly be divided into four phases.
wikipage: Timeline of the North Korean nuclear program
content: The nuclear program can be traced back to about 1962, when North Korea committed itself to what it called "all-fortressization", which was the beginning of the hyper-militarized North Korea of today.
wikipage: North Korea and weapons of mass destruction
content: Soviet engineers took part in the construction of the Yongbyon Nuclear Scientific Research Center[15] and began construction of an IRT-2000 research reactor in 1963, which became operational in 1965 and was upgraded to 8 MW in 1974.
wikipage: North Korea and weapons of mass destruction
content: On October 9, 2006, North Korea announced it had successfully conducted its first nuclear test.
wikipage: North Korea and weapons of mass destruction
long_answer: The North Korean nuclear program can roughly be divided into four phases. The Phase I of the North Korean nuclear program, in which North Korean nuclear program started getting training for scientists began in 1956. The nuclear program can be traced back to about 1962, when North Korea committed itself to what it called "all-fortressization". North Korean began construction of an IRT-2000 research reactor in 1963 and on October 9, 2006, North Korea announced it had successfully conducted its first nuclear test.