LESS THAN STANDARD SEPARATION WHEN MLT Y IS DESCENDED THROUGH THE ALT OF MLT X WITH INSUFFICIENT LATERAL SEPARATION.

Narrative

NUMEROUS DEPS (XXX AIRLINES) DEPARTED RDU (RWY 23) MAKING WIDE LEFT TURNS CLBING TO FL230 AND ABOVE. TFC WAS INBND RDU VIA ARGAL INTXN V66 AND VIA OXFORD INTXN V3. A FELLOW CTLR PASSING BY DECLINED HIS BREAK AND OFFERED ASSISTANCE. I GLADY ACCEPTED AS IT STARTED TO GET BUSY. SMT Z REQUESTED CLRNC AND DEPARTED RWY 1 WBOUND TO CLT CLBING TO 12000'. SMT Z WAS GIVEN A VECTOR NWBOUND TO REMAIN CLR OF TFC INBND FROM THE SW AT 4000'. MLT X WAS GIVEN REROUTE AWAY FROM HEAD ON ACR DEPS VIA TYI V213 WALLO V56 FAY-FBG. GSB ECHO MOA WAS ACTIVE UP TO FL200 (ACROBATIC AREA SE OF RDU SW TO TYI). 2 MLT'S WERE INBND TO GSB VIA RDU HDG 090 DEGS RADAR VECTOR CLR OF TFC AND DIRECT GSB; ONE AT 16000' AND ONE AT 23000' (MLT Y). ALL THE ACFT BEING HANDLED AT THIS TIME; WITH THE EXCEPTION OF A FEW; WERE CLBING AND DSNDING (16 AT THE TIME OF THE INCIDENT; PROBABLY MORE BEFORE) ON A SCOPE WITH A 60 MI RANGE (DIAMETER). NEEDLESS TO SAY; IT BECAME VERY BUSY AND VERY HECTIC. REQUIRED A CONSIDERABLE AMOUNT OF COORD AND SEP. SMT Z WAS KEPT IN CONSTANT VIGILANCE CLBING IN THE FACE OF ACR JET DEPS REQUIRING CONTINUAL COORD WITH RDU APCH CTL. DURING THIS TIME I REMEMBER SAYING AFTER TURNING MLT Y TO HDG 120 DEGS; 'I HAVE A CLR SHOT; I'M DSNDING HIM TO 11000'.' OUR ATTN WAS DIRECTED BACK TO SMT Z AND MLT Y DSNDED APPROX 2 MI IN FRONT OF MLT X AT 16000'. THEY SAY THE C/A WENT OFF; I DID NOT SEE IT.