U.S. Demands N. Korea’s Nuclear History : Asia: Washington wants to learn how much plutonium may have been made. It also insists the North get a new reactor from the South. Pyongyang is not cooperating.

In an attempt to alleviate Japanese and South Korean uneasiness, Robert L. Gallucci, America’s chief negotiator with North Korea, declared here Wednesday that the United States will insist that North Korea clarify the history of its nuclear development as part of any Washington-Pyongyang agreement.

He also offered an unqualified assurance that the United States will insist on North Korea accepting a South Korean light-water reactor as the only “politically, economically and technologically feasible” replacement for two gas graphite reactors that North Korea is building.

In its public statements, North Korea has so far rejected both demands.

Gallucci made the statements in separate news conferences at the U.S. Embassy and the Japan National Press Club.

In July, President Kim Young Sam of South Korea and Prime Minister Tomiichi Murayama of Japan agreed that the two nations will insist on a clarification of North Korea’s past nuclear record as a prerequisite to cooperating with any agreement the United States might work out with North Korea.

Officials of both nations have expressed fears that the United States might drop attempts to learn how much plutonium North Korea may have produced in the past--suspicions range up to 22 pounds--in favor of stopping future North Korean production of more than 350 pounds of plutonium a year through reprocessing of spent fuel from the two new reactors.

Gallucci, however, declared that “the United States certainly would not cooperate in . . . the supply of any significant nuclear equipment” if North Korea does not make clear “what happened in the past” by submitting to special inspections, Gallucci said.

The United States, he said, would be flexible about when, during the process of implementing an overall agreement, North Korea would allow the special inspections.

But “it is inconceivable that the United States, Japan or South Korea would tolerate an indefinite failure to resolve the historical question,” he said.

Gallucci said the United States is also concerned about the continuing construction of the two reactors that “would produce hundreds of kilograms a year--eventually thousands of kilograms over 10 years--of plutonium. The strategic significance of these reactors . . . as components of a nuclear weapons program . . . is quite large.”

The two reactors combined, he said, could enable North Korea to produce more than 160 kilograms, or more than 350 pounds, of plutonium annually.

The ambassador-at-large said he was aware that North Korea has sounded out “countries other than South Korea” about a light-water reactor as a substitute for the gas graphite reactors it has offered to scrap as a part of an overall agreement with the United States.

But “after quite a bit of work and consultations with other governments,” the United States now believes, he said, that “the only technically, politically and financially viable model would be one in which South Korea played a central role, both in financing and construction.”

Although other countries, such as Japan, would contribute to the $4-billion, 2,000-megawatt light-water reactor, South Korea would provide a major share of what is expected to be an interest-free loan to North Korea to build the reactor, Gallucci said.

South Korean technicians would also take part in construction of the reactor, he said. So far, North Korea, which maintains one of the world’s most closed societies, has refused to allow South Koreans to come into widespread contact with its citizens.