Secretary of Defense Richard B. Cheney will meet with directors of the three U.S. nuclear weapons laboratories today to discuss their safety concerns about nuclear-tipped short-range missiles carried by strategic aircraft on war "alert," spokesmen for the Department of Defense and the Department of Energy announced yesterday.

The meeting was set a day after the Pentagon announced it would not decide until later this summer whether to withdraw the Short-Range Attack Missile-As, or SRAM-As, from service on alert B-1, B-52, and FB-111 bombers and store the missiles, as the directors unanimously advised in congressional testimony earlier this week.

The scientists are concerned that the weapons could explode in an accidental aircraft fire, dispersing dangerously radioactive materials from the core of the W-69 nuclear warhead carried aboard each missile.

Secretary of Energy James D. Watkins, who earlier this year insisted that President Bush be told of the SRAM-A safety problems, will accompany the lab directors, the spokesmen announced. His agency manages the design of nuclear weapons at the laboratories in Albuquerque, N.M., Los Alamos, N.M., and Livermore, Calif.

"If there is new information about the SRAM-A, I want to hear it," Cheney said through his spokesman, Pete Williams.

Speaker of the House Thomas S. Foley (D-Wa.), who has an Air Force base equipped with "alert" B-52 aircraft in his district, said he telephoned Cheney on Thursday to request that Cheney give the lab directors' recommendations "his highest consideration."

"Although extraordinary precautions have been taken to ensure the safety of the SRAM missile, this week's cautionary testimony by top nuclear weapons designers reminds us that even the highest nuclear weapons standards can be improved," Foley said. Cheney called Foley yesterday to inform him of the plan for an immediate high-level review, a spokesman for Foley said.

Sen. J. James Exon (D-Neb.), who has the Strategic Air Command headquarters in his state, and Rep. John Spratt (D-S.C.), chairman of a special House panel on defense nuclear facilities, have said they favor withdrawing the SRAM-As from "alert" aircraft.

The Pentagon meeting today will include senior officials of the Air Force, which last year altered some procedures to diminish the risk of fires aboard "alert" strategic aircraft ready for takeoff on short notice.

Williams had earlier said the lab directors were presenting their "personal opinions" on more than just the scientific questions associated with the safety of the SRAM-As. Another senior defense official, who insisted on anonymity, criticized Undersecretary of Energy John Tuck for indicating in congressional testimony that the weapons would probably be withdrawn after a special SRAM safety study is concluded this summer.

The Defense Department has taken the position that no decision should be made until the study is complete and the safety risks have been weighed against the military value of keeping SRAMs on alert bombers.

Several DOE officials and independent sources yesterday said DOD nuclear weapons safety standards do not specifically bar weapons such as the SRAM from dispersing radioactive materials. The DOD standards require that nuclear weapons not be inadvertently fired or launched, and that any accidental explosion not produce a nuclear yield.

"This is why the department was able to assert that the SRAM weapon meets its current safety standards," one source said, referring to a statement by Williams.

DOE, in contrast, is required by its nuclear weapons safety standard "to assure that everything practicable has been done" to prevent an accidental explosion of the volatile component surrounding the nuclear materials at the core of a warhead, resulting in a dangerous dispersal of the materials even in the absence of a nuclear yield.

The laboratory directors have been concerned for more than a year about this possibility, officials said, based on extensive statistical analysis of the likelihood of accidental aircraft fires.