AIKEN, S.C. (AP) _ A small crack has been discovered in a cooling pipe at a reactor at the Savannah River Plant nuclear facility, but it should not affect next summer's scheduled restart of the reactor, Energy Department officials said Saturday.

Len Sjostrom, the Department of Energy's acting assistant manager for reactor operations, said that the crack in the 4-inch pipe occurred in a weld area where two pipes join, the Augusta (Ga.) Chronicle reported in Sunday's editions.

The pipe supplies cooling water to reactor control rods, which are raised and lowered within the reactor vessel to control the fission process.

Sjostrom said the crack was detected Friday by ultrasonic tests during a routine check of the reactor's piping. He said he thought this was the first crack found in the reactor's piping this year.

All three SRP reactors - known as the K, L and P reactors - have been shut down since summer for safety upgrades and maintenance. They are the nation's only source of tritium, a radioactive gas used to boost the power of nuclear weapons.

Because tritium decays 5.5 percent annually, some federal officials say the nation could face forced reductions in nuclear weapons unless the reactors are restarted soon.

In Washington, Richard W. Starostecki, the Energy Department's deputy assistant secretary for safety, health and quality assurance, said he was sending a team of experts to the weapons plant next week to assess the situation, The New York Times reported in Sunday's editions.

Sjostrom said replacing the pipe would not delay restart ''because we have the time to do it ... and especially because it's a smaller pipe.''

The K Reactor crack was discovered the same day Energy Department officials said a separate crack found earlier in the L Reactor presented no major safety problems and could have been caused by nearby welding.

Sections of pipe are replaced when a crack penetrates more than 50 percent of a pipe wall's thickness, or covering more than 20 percent of the pipe's circumference.

The L Reactor pipe was removed under that rule, and the pipe in the K reactor found cracked Friday will be replaced even though it does not meet the criteria, the Augusta paper reported.