Toshiba Corp’s claim that it is owed $2.15 billion by Chicago Bridge & Iron Co NV (CB&I) hinges on how an independent auditor will calculate the net working capital of a U.S. nuclear power plant construction business that CB&I sold to Toshiba’s Westinghouse unit last year. WHAT IS NET WORKING CAPITAL? Net working capital is a measure of the financial strength of a business, defined as its current assets minus its current liabilities.