TERRACE BAY, Ont. — The operator of the pulp mill at Terrace Bay has quietly set aside its plan to convert the facility to produce dissolving grade pulp for manufacturing rayon. AV Terrace Bay’s parent company, India-based Aditya Birla Group, is betting that – at least for now – continuing to make northern bleached softwood kraft (NBSK) pulp is more likely to ensure the mill’s long-term stability. When it acquired the mill in 2012, Aditya Birla planned to spend $250 million over two years on a conversion from production of NBSK. But in a statement issued this week, the company said “given the current market conditions of dissolving grade pulp, there is no immediate plan to convert the mill.”  Nonetheless,  AV Terrace Bay is still spending significant sums on upgrades.