A TRACON controller reported vectoring an aircraft off their approach to avoid unidentified VFR traf...

Narrative:

Aircraft X was direct wuvon descending to 4;000 to intercept the final approach course to eventually get the field in sight and cleared for a visual approach. Aircraft Y was about 5 miles in trail direct frnny going slightly faster than aircraft X. As aircraft X was approaching the final; I observed that there was an unidentified VFR aircraft at their 11 o'clock northeast bound climbing out of 3;300 feet. I instructed aircraft X to amend their altitude to 4;500 for traffic. VFR traffic and aircraft X were going to merge so I turned aircraft X to go behind the traffic. This in turn caused aircraft X at 4;500 to cross the path of aircraft Y who was level at 5;000.in the process of recovering separation between aircraft X and aircraft Y; aircraft X descending to 5;000 may have penetrated niles airspace. Aircraft X was turned to a heading of 340 to continue their descent and away from niles airspace.I should have just turned aircraft X northbound; climbed and possibly resequenced them when the VFR target further became a factor. With aircraft Y 5SM in trail and keeping his speed at a higher velocity; it would have been the easiest option.

Original NASA ASRS Text

Title: A TRACON Controller reported vectoring an aircraft off their approach to avoid unidentified VFR traffic lost required spacing with the arriving in trail traffic.

Narrative: Aircraft X was direct WUVON descending to 4;000 to intercept the final approach course to eventually get the field in sight and cleared for a visual approach. Aircraft Y was about 5 miles in trail direct FRNNY going slightly faster than Aircraft X. As Aircraft X was approaching the final; I observed that there was an unidentified VFR aircraft at their 11 o'clock northeast bound climbing out of 3;300 feet. I instructed Aircraft X to amend their altitude to 4;500 for traffic. VFR traffic and Aircraft X were going to merge so I turned Aircraft X to go behind the traffic. This in turn caused Aircraft X at 4;500 to cross the path of Aircraft Y who was level at 5;000.In the process of recovering separation between Aircraft X and Aircraft Y; Aircraft X descending to 5;000 may have penetrated Niles airspace. Aircraft X was turned to a heading of 340 to continue their descent and away from Niles airspace.I should have just turned Aircraft X northbound; climbed and possibly resequenced them when the VFR target further became a factor. With Aircraft Y 5SM in trail and keeping his speed at a higher velocity; it would have been the easiest option.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1491237
Time
Date	201710
Local Time Of Day	1201-1800
Place
Locale Reference	OAK.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Widebody Transport
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Airspace Violation All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

A TRACON controller reported vectoring an aircraft off their approach to avoid unidentified VFR traffic lost required spacing with the arriving in trail traffic.