"required upon" is a correct and usable phrase in written English.
You can use it to express something that must be done at a certain time or upon certain conditions being met. For example, "Payment is required upon delivery of the goods."
Please include your name, address and daytime telephone number (required); upon request, names may be withheld in print.
Some 145 cardinals gathered on the first day of meetings required upon the end of a papacy — usually by death, but in this rare case, resignation.
Other reported components include a 500GB internal hard drive (mostly for installing games, which is now said to be required upon a game's first launch), as well as a Blu-ray drive.
The results of the present study clearly show that action was required upon hydrocortisone-induced glycemic variability, as the total number of blood glucose level measurements were almost three times as many as in patients not receiving hydrocortisone treatment.
This elastic feature was also observed in the simulations starting from the apo form which suggests low free energy barrier between the two conformations and small compensation required upon binding.
The station parking lot contains 170 spaces, with payment required upon entering for daily use and a permit required for monthly use.
Forecasting the geomagnetic field requires, upon accurate observations at or above the Earth's surface, understanding the physics occurring within the Earth's outer core over millennial to interannual time-scales.
has declared an equivalent number of square miles off limits to Russians - even though it required drawing upon 32 counties in Kansas.
After fierce debate, residents decided to abandon rules that required them, upon moving, to sell their shares back to the cooperative at the original price.
A statement from her management said: "Danielle sustained a serious wound to her back which required stitches upon arrival at hospital".
One patient in the II developed acute kidney and required hemodialysis upon discharge from the hospital.
