Orbital Period Changes in Recurrent Nova T Corona Borealis Prove That It Is Not a Type Ia Supernovae Progenitor

T Corona Borealis (T CrB) is a recurrent nova and a symbiotic star that is commonly highlighted as the best case for being a progenitor of a Type Ia supernova (SNIa) within the framework of single-degenerate models. This exemplar can be tested by measuring whether the white dwarf (WD) mass (MWD) is increasing over each eruption cycle. This is a balance between the mass ejected during each nova event (Mejecta) and the mass accreted onto the WD between the nova events (Maccreted). I have used all 206 radial velocities from 1946--2024 to measure the orbital period just after the 1946 eruption to be Pₚₒₛₜ=227.6043 days, while the steady orbital period change (Ṗ) is ($-$3.1±1.6)×10⁻⁶. I have used my full 213,730 magnitude B and V light curve from 1842--2025 to measure the times of maximum brightness in the ellipsoidal modulations to construct the $O-C$ from 1866--1946. I fit the broken parabola shape, to find the orbital period immediately before the 1946 eruption to be Pₚᵣₑ=227.4586 days. The orbital period changed by $ΔP$=$+$0.146±0.019 days. With Kepler's Law, conservation of angular momentum, and the well-measured binary properties, the ejecta mass in 1946 is 0.00074±0.00009 M_. Maccreted is reliably measured to be 1.38×10⁻⁶ M_ from the accretion luminosity. Mejecta is larger than Maccreted by 540×, so MWD is { decreasing} every eruption cycle. T CrB can never become a SNIa.