Project Duration

Hello Sir, Just a quick question in relation to project duration. Would I be right in saying that similarly to Macaulay Duration, would dividing the project duration by the WACC used to calculate NPV give a modified duration for a project i.e. an indication of how sensitive the NPV of a project is to increases in rises in cost of debt or shareholders required rate of return? and in turn could this be used to calculate IRR? Thanking you, John