Poland’s biggest oil refiner PKN Orlen is calculating losses related to tainted Russian oil supplies and will submit its claims within weeks, the chief executive said on Friday. Russia halted oil supplies through its Druzhba export pipeline in April after the discovery of excessive levels of organic chloride, which can damage refinery equipment. Supplies of clean oil to Poland partially resumed in June. “We are calculating our losses when it comes to claims resulting from the worse quality of oil. When we calculate this within weeks, we will present our claims,” CEO Daniel Obajtek told reporters. “We will submit our claims to the suppliers,” he said, adding that other refineries were making similar calculations which included determining the cost of any related shutdowns. […]