Soviet military reservists who were called to duty in the Carpathian region bordering Poland when the Polish crisis erupted last August have been returned to civilian status subject to quick reactivation, reliable sources said today.

The accounts reaching here, believed credible by informed Western sources, assert that deactivation of reservists in the region began in mid-December and that almost all are now back at their normal civilian jobs.

The sources say, however, that factories and other places of work in the strategic military district in the western Ukraine have recieved special instructions to keep the reserves near at hand in case they are to be called up again.

The sources say this is one of various measures taken by Soviet authorities following the August call-up, which these accounts say was marked by extraordinary confusion, disorder and wholesale desertions by reservists from mustering points and bivouacs. The sources assert that the initial activation was so unsuccessful that it has led to the dismissal of senior staff reservists responsible for reserve readiness in the Carpathian region.

A Soviet Foreign Ministry spokesman last December denied that reservists had been called up in Carpathia or any of the 15 other Soviet military spokesman was not available for comment tonight.

Western sources here said the reported activation in mid-August was consistent with irregularities seen in Soviet troop rotation patterns. They said the reports of deactivation also sounded consistent with more recent indications of Soviet military readiness along the Polish frontier.

Western sources here still consider general Soviet military readiness along the Polish border to be high, despite the reported deactivation of reserves, who would be used in general support capacities in any use of force. Some informed foreign sources believe the Soviets reached a peak of readiness in mid-December but that regular forces in the border areas have now been placed in a slightly lower state of readiness.

The Soviet sources said discipline among the reserves, who were said to have been told only that they were being called for "retraining," was a major problem from the beginning. These sources alleged that the reservists, with families and friends nearby, melted away from their duties in numbers so large that punishment became impossible.

They cited persistent insubordination, low morale and poor performance as major problems. These were said to have been major factors leading to the order to disband.

Even the deactivation, they said was marked by confusion and disorganization. One unit, they asserted, was assembled and moved three times in the last three days before being released from duty.

The call-up frustrated factory and plant managers who lost parts of their work force, adding to the general unhappiness and confusion, the sources said. There is now way to independetly verify any of these reports. The Carpathian region is generally closed to foreigners.

The Soviet military paper, Red Star, has for more than a year emphasized in articles the need for better discipline and orderliness in the ranks, leading the Western sources to speculate that the accounts of insubordination and other troubles with the reservists' performance seems plausible.

The Soviet sources said that a general tightening up of regulations for reservists is now being imposed in the region, making it virtually impossible for reservists to obtain medical excuses or requests from their bosses to be excused from any future call-up.

It is not known here whether the accounts from Carpathis are reflective of the situation in the two other principal Soviet border military districts of Byelorussia and the Baltics.