Ultra-Low Energy technology, which was also presented in Stamicarbon symposium 2012 as 5XX design, is successfully implemented in two grass-root plants in China) in 2017 and 2018 for a similar 2334 MTPD urea plant capacity. The start-ups of these plants are scheduled in Nov. 2020 and March 2021 respectively. This paper highlights the experiences related to the design of the Ultra-Low Energy plant along with an emphasis on the special pool reactor design with dual bundle (steam and carbamate). The Ultra-Low Energy technology for a melt plant with prilled product results in the steam consumption (23 bara, 330 ºC) ≤ 558 kgsteam/tonproduct compare to traditional Urea 2000plus® process ≤ 868 kgsteam/tonproduct.