With White House approval, the Department of Energy has begun the transfer to other nuclear weapons projects the funds originally earmarked for testing and production of neutron weapons this fiscal year.

Should President Carter eventually decide to build the controversial new generation of tactical nuclear weapons, the shift of funds now under way could postpone, probably until 1979, a start on production.

"We did not expect this long a delay in the neutron decision," a DOE official said last week after noting that almost half of fiscal 1978 has gone by.

By law, COngress has 45 days to debate and vote once a Carter neutron production decision is made. Although no reversal of the president is expected, the congressional debated would delay implementation of the order.

A State Department source said last week he expected a Carter neutron decision by mid-April "so the matter will be debated by Congress and out of the way" by the end of May when a NATO summit meeting is scheduled to take place in Washington.

Carter, however, has yet to make a production decision, although one was first promised for last August.

For six months, administration officials have been consulting and negotiating with North Atlantic Treaty Organization allies on whose soil the neutron would be deployed.

Though Congress has debated and approved production of the weapons, no western European country has approved them. The Netherlands, has approved them. The Netherlands, the only country whose parliament voted on the issue turned them down.

The proposed neutrin 8-inch artillery shells and Lance missile warheads have thus become a political problem within NATO. At the same time, The Soviet union has tried to make neutron weapons an international issue.

Nuclear shells and warheads noe deployed in Europe destroy targets such as tanks and fortifications primarily through heat and blast. Neutron weapons, on the other hand, are designed to kill ot incapacitate enemy troops, primarily by radiation.

Proponents say neutron weapons would be more credible deterrents Europe. The reasoning is that, because they produce less blast and heat, they would cause less adjacent to a battlefield. Thus, proponents argue, they would be more likely to be used in a crisis than would be bigger, more destructive nuclear warheads and bombs now in Europe.

Opponents counter that neutron shells thus lower the nuclear threshold - the level at which nuclear weapons would first be used.

Last December, West German Chancellor Helmut Schmidt Proposed that the United States attempt to use neutron weapons as a bargaining chip with the Soviets - perhaps for a reduction in the number of new mobile intermediate-range Soviet missiles, the SS20 class.

Under Schmidt's plan, negotiations would take place during the two years between the time neutron weapon on production began and the time shells and warheads were ready for deployment.

Schmidt's suggestion came in part because key elements in his ruling Socialist Party strongly opposed deployment of neutron weapons on West German soil.

His idea is among several proposals being discussed in the Carter administration and with other NATO governments.

But it has several problems, assording to Carter aides.

TH main one if that it would require the president to make his production decision alone without the NATO allies publicly giving their support to the decision.

Carter, according to aides, has maintained during the current negotiations that the allies must join with him in making the production decision.

Some Carter aides are proposing that production be delayed while disarmament avenues with the Soviets are explored.

While talks go on, production problems grow.

Before the neutron 8-inch shell can be built, DOE has to construct $45 million in special facilities for its fabrication. The $23 million in fiscal 1978 monwy for that project has been put into another program.

The Lance neutron warhead was originally proposed because the last Lance regular nuclear warhead was originally proposed because the last Lance regular nuclear warheads were just being produced! The neutron versions were to fit on the end of that production run.

With the delay, however, Lance production has ended, according to DOE officials, and the assemble lines have shut down. To reestablish them just for the limited number of Lance neutron warheads presents a costly problem - one that may rule out any neutron Lance.