The Pentagon plans to build so many new strategic and tactical nuclear weapons for the 1980s Congress has been told that the United States will have to increase its production of weapons-grade plutonium.

Though these weapons programs grew under the Nixon and Ford administrations, the decision on whether or not to increase plutonium production will be President Carter's probably this fall.

He has talked to the Soviet Union about cutting back on nuclear weapons, but said last week if negotiations fail, the United States will have to do what it considers necessary for its security.

Yet President Carter has called on other countries to limit production of plutonium, the daily explosive element used in making nuclear bombs.

"We need more plutonium in the mid-80s . . . than we have now," Maj. Gen. Joseph K. Bratton, director of the Military Application, told a closed session of a House Armed Services subcommittee on April 27.

Nuclear weapons systems now in the research and development stages, "when added to the other new systems which have been approved," Bratton said. ". . . simply build up the cumulative requirement for plutonium even when taking into account the dismantling and retirement of weapons w* hich will return some plutonium back into the system."

As a first step in increasing plutonium production, Bratton proposed converting a nuclear reactor at Richland, Wash., from production of fuel-grade plunium to weapons-grade.

When a committee member noted that step might be inconsistent with Carter's April 7 statement calling for limits on plutonium production, Rep. Charles H. Wilson (D-Calif.) responded. "The President's statement is as inconsistent as my golf scores, so I think perhaps we should go ahead and produce this plutonium."

"I agree," Rep. Samuel S. Stratton (D-N.Y.) then said.

Almost all the new U.S. production of weapons-grade plutonium now takes place at Savannah River, S.C.

The Richland N-reactor presently produces "reactor fuel-grade plutonium," according to ERDA officials, which would be used to start the Clinch River breeder reactor, if that is ever completed.

Some N-reactor plutonium is also mixed with Savannah River plutonium to make a weapons-grade materials.

The N-reactor also produces $20 million worth of steam which is sold each year to the Pacific Northeast River Basins Commission. The commission uses it to power generators that turn out 4 per cent of the electric power in that area.

Bratton said last week that the $12 million needed to convert the Richland reactor will be requested in the ERDA fiscal 1979 budget, which is now undergoing review.

In his April presentation to the Armed Services subcommittee. Bratton said the following nuclear weapons programs will require the plutonium production increase.

Trident I warheads. The Trident is a sub-marine-launched long-range missile that will have several types of multiple warheads, each with 14 or more separately targeted hydrogen bombs. The SE have been approved for production.

The W-78 warheads, designed for Minuteman II land-based long-range missile. Called the Mark 12-A, it is said to be more accurrate than present Minuteman wareheads and carries three hydrogen bombs. Production is approved.

The W-79. 8-inch neutron artillery projectile.This is one of two neutron weopons approved by the Ford administration. That decision is now being reviewed by the President. Production is expected, through how many will be built is classified. There are 450 8--inch tubes in Europe.

The W-80 warheads, designed to be common for the cruise missiles and short range attack missile (SRAM-B). The SRAM-B was designed primarily for the B-1 is expected by Bratton and others to lead to more nuclear W-80 warheads than originally planned. Production is approved, though numbers may change.

The W-70-3, the neutron warhead for the 56-mile-range Lance missile. Here again, the President must make his decision, but production is expected to be approved. Numbers will be limitted, since only the last of three versions of the Lance warhead is involved...

The B-61 bomb, three versions of which have been approved for production with different yields. They are for use by tactical fighter bombers. Present bombs have yields said to range from less than a kiloton to a megaton.

The B-77 bomb. Designed primarily for delivery by the B-1. Pentagon and ERDA officials say they want it built despite the B-1 cancellation can be delivered by the B-52, the F-111 and some Navy and Air Force fighter-bombers. The B-77 is built with a new insensitive high explosive that allows the bomb to be dropped from a plane flying at supersonic speeds several hundred feet off the ground and yet not explode even though it hits a cement building. The delay in explosion is needed to permit the plane to be out of the affected area when the bomb goes off.

The X missile, a warhead for the M-X system, designed to be a follow on system to the land-based Minuteman. Still in development, currentplans forcast 12 to 14 hydrogen bombs per missile, each with enough power to destroy a Soviet launching silo.

The Trident II, the submarine-launched version of the M-X. Also in development.

The neutron 8-inch artillery projectile is expected to replace older nuclear shells now in the inventory. The B-61 bombs are also planned as replacement for older bombs.

But, according to Bratton, "the additional Trident missiles and the SRAM's and cruise missiles . . . are not really replacing anything in kind. [They] are an add-on to the stockpile."

Bratton told the House subcommittee that ERDA had requested the $12 million o begin converting the Richland N-reactor to weapons-grade plutonium last year, but the Ford Office of Management and Budget turned it down.

"The rationale used in OMB was to defer the action one year," Bratton said.

In a recent interview Bratton said it was "prudent" to expand plutonium production as "a hedge against that unknown" in terms of weapons President Carter will approve for production in coming years.

He said the M-X and Trident II in particular, would put heavy demands on plutonium needs.

If some of the weapons he listed went ot production, Bratton said he thought a second reactor now on standby at Savannah River would have to be put back production.

"These are long lead-time decision," Bratton said, but added that they would be before the President shortly in the form of the annual nuclear testing and stockpile program. Under law, the President must personally approve all testing, production and deployment of nuclear weapons.