We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date .
The observations were obtained at 450 ~ { } \micron and 850 ~ { } \micron with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey .
The emission at 850 ~ { } \micron peaks at 40 \arcsec with hints of a second peak seen at \sim 20 \arcsec .
The emission can be traced out to a radius of 56 \arcsec at a 3 \sigma level .
The outer peak observed at 850 ~ { } \micron aligns well with the peak observed at Herschel/PACS wavelengths .
With the help of spectral energy distribution fitting and radiative transfer calculations of multiple-shell models for the circumstellar envelope , we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope .
We determine a total shell dust mass of ( 2.0 \pm 0.3 ) \times 10 ^ { -5 } M _ { \odot } and established that the thermal pulse which gave rise to the detached shell occurred 3500 \pm 500 years ago .