OK…just to continue the hijack a bit, when I looked at your cite a bit furter and saw who it was put out by I decided to google a bit more…
A couple more relevant points
Wiki…
“Anti-nuclear sentiment had triggered the election of 1984. In the context of a global nuclear free movement caused by mounting Cold War tensions between the United States and the Soviet Union, visits to New Zealand by US navy ships caused publicity and protest. In June 1984 Labour MP Richard Prebble introduced a bill (one of a series since the 1970s) to ban nuclear armed and powered ships, as well as nuclear reactors and waste. The National government at the time had a majority of one, and MP Marilyn Waring crossed the floor to support the nuclear free legislation. Prime Minister Robert Muldoon claimed that Waring’s “feminist anti-nuclear stance” threatened his ability to govern, and called a snap election. After winning the election Labour entered office with the intention of declaring New Zealand nuclear free; the party had proposed to renegotiate the ANZUS treaty to incorporate a nuclear free nation. The critical moment in relations with the US came when in 1985 when New Zealand refused a request from the destroyer USS Buchanan (DDG-14) on the grounds that it was capable of carrying nuclear weapons. New Zealand was subsequently ejected from the American Alliance”
and
Auckalnd University
"In July 1984 a newly elected Labour government implemented a policy which dissociated New Zealand’s military establishment from the nuclear component of the then-Cold War confrontation. In 1987 the New Zealand Nuclear Free Zone, Disarmament and Arms Control Act was passed, giving legal force to the policy. Although the passage of the Act was regarded by the United States as a near-hostile action on the part of New Zealand, none of its three explicit purposes would have been expected intrinsically to evoke international controversy. These purposes are:
(i) to establish a Nuclear Free Zone in New Zealand,
(ii) to promote and encourage an effective contribution by New Zealand
to international disarmament and arms control,
and (iii) to implement locally a number of treaties to which New Zealand is
party, specifically, the Partial Test Ban Treaty, the Nuclear Non-
Proliferation Treaty, the Sea-bed Treaty, the Biological Weapons
Convention and the Treaty of Rarotonga (which created the South
Pacific Nuclear Free Zone)."
Bear in mind this was around the time of Rainbow Warrior bombing, which was tied to Nuclear Bomb testing in the Pacific by the French. I may be conflating the issues a little.
I certainly remember the BOMB part getting much more play than the power part - so much so that I was surprised to find the ban on power is included in the original act.,
Butr going by those two sources, non-proliferation was a major driver of the legislation. Nuclear power is a much smaller issue for New Zealand, and I would have thought if that was the only issue, then an accomodation would have been made.