Document: NRC Regulatory Guide
Document ID: e7cef6d0-2869-4d77-9a08-126120ae6043
Document Type: regulatory_guide
Title: Fuel Oil Systems for Emergency Power Supplies + HISTORY – HISTORY 06/2012 – DG-1282 , Proposed Revision 2 Prior to the issuance of DG-1282, RG 1.137 was entitled "Fuel –Oil Systems for Standby Diesel Generators (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1210/ML121090447.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.137
CFR Part: 
CFR Title: 

Content:
ue to general, pitting, crevice and microbiologically-influenced corrosion (MIC) and fouling that leads to corrosion of the fuel tank internal surfaces. 13.10. The NRC does not regulate emissions from emergency power supply drivers and consequently does not provide specific guidance for the level of sulfur in the fuel oil. However if ULSD grade (S15) of fuel oil is used, the oil stored in the fuel oil supply tank, and the oil to be used for filling or refilling the supply tank, should meet the requirements of ASTM D975-11 (the use of ASTM D975-92 and earlier editions does not address ULSD fuel) and the diesel generator or gas turbine manufacturer’s requirements. The process used to reduce sulfur may also change other properties of diesel fuel. The potential changes are expected to include lower energy content (of the order of 1% to 2%), different cetane number, greater tendency to form particulates in storage, lower lubricity, and reduced compatibility with gaskets, seals, and engine lubricating oil. NRC Information Notice IN 2006-22, “New Ultra-Low Sulfur Diesel Fuel Oil Could Adversely Impact Diesel Engine Performance” (Ref. 23), describes some of the properties of ULSD fuel and the potential effects on engine performance. Licensees should be aware of the potential impacts of ULSD and verify the quality and compatibility of the fuel in accordance with ASTM D975-11 and the supplements listed in this section. 13.11. Biologically based diesel fuels (also known as “biodiesel”), of any concentration, should be used with caution because of the uncertainty about the chemical and physical properties of the formulations and their potential impact on diesel performance and fuel oil system components. This includes ethanol-fortified grades. ASTM D975-11 considers blends with up to 5% biodiesel not to be a biodiesel grade. Therefore, licensees should not assume that purchased diesel fuel is free of any biodiesel without verification by the supplier before adding new