Information Notice 1996-67, Vulnerability of Emergency Diesel Generators to Fuel Oil/Lubricating Oil Incompatibility

Vulnerability of Emergency Diesel Generators to Fuel Oil/Lubricating Oil Incompatibility

ML031050485
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	12/19/1996
From:	Martin T Office of Nuclear Reactor Regulation
To:
References
IN-96-067, NUDOCS 9612160113
Download: ML031050485 (7)

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UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 December 19, 1996 NRC INFORMATION NOTICE 96-67: VULNERABILITY OF EMERGENCY DIESEL

GENERATORS TO FUEL OIL/LUBRICATING OIL

INCOMPATIBILITY

Addressees

All holders of operating licenses or construction permits for nuclear power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert

addressees to a recent finding involving degradation of the power block assembly of two

emergency diesel generators caused by an incompatibility of the lubricating oil with fuel oil

with a low sulfur content. It is expected that recipients will review the information for

applicability and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this notice do not constitute NRC requirements; therefore, no

specific action or written response is required.

DescriDtion of Circumstances

In December 1995, during preoperational testing of a new safety-related emergency diesel

generator (EDG), test engineers for the licensee, Baltimore Gas and Electric Company

(BGE), at the Calvert Cliffs Nuclear Power Plant, noted sporadic spikes in crankcase

pressure and lubricating oil seeping out from the crankshaft seal. The engine was shut down

and BGE conducted a boroscopic inspection of the unit. One cylinder showed indications of

abnormal wear. The cylinder liner, piston, and piston rings were removed for analysis and

replaced with a spare set. The testing program resumed, with normal crankcase parameters

being indicated.

The test program for the safety-related EDG was completed on January 8, 1996. Several

days later, during a scheduled 2-year maintenance inspection, BGE found four cylinders with

heavy carbon-like deposits on the pistons and behind the piston rings and evidence of

abnormal scuffing on the cylinder liners. On further inspection, all the cylinders exhibited

some degree of similar degradation, including the replacement cylinder. BGE then inspected

a second new EDG that had been installed as a backup power supply in 1995 for station

blackout. One cylinder on the station blackout engine exhibited degradation similar to that of

the safety-related EDG. Upon disassembly, excessive carbon deposition was found in all

cylinders.

9612160113 G96R 7-00 9614?

IN 96-67 December 19, 1996 Discussion

Calvert Cliffs Nuclear Power Plant comprises two Combustion Engineering reactors with three

EDGs, one dedicated to each unit and the third a "swing" EDG, that automatically loads onto

the accident unit. In 1989, BGE initiated a modification to upgrade Calvert Cliffs emergency

electrical system and meet the requirements of the station blackout rule. The modification

included the installation of one safety-related EDG (giving each unit two dedicated EDGs)

and one nonsafety-related EDG capable of powering any of the four safety-related 4-kV

emergency electrical buses (for station blackout purposes). The new EDGs are basically

identical, each with two engines in tandem with the generator between the engines. The

EDGs were manufactured by Societ6 Alsacienne de Constructions M6chaniques de Mulhouse

(SACM) and have a nominal continuous rating of 5400 kW.

When the cylinder degradation was found, BGE assembled a root cause analysis team, which

included persons with recognized industry expertise. The team developed three potential

causes for the diesel power block degradation: components not to design specifications, improper operation of the engines, and lubricating oilfuel oil incompatibility. The first

possibility was ruled out by metallurgical and dimensional analysis and the second from

discussions with SACM and other operators of SACM diesel generators. The team

concluded that the lubricating oil used was incompatible with low sulfur content fuel.

The BGE team found that lubricating oil compatibility depends, in part, on the type of fuel

being burned, as the lubricating oil contains an additive package that neutralizes the products

of combustion, most importantly sulfuric acid, to prevent engine corrosion. The lubricating oil

originally selected was an American Petroleum Institute (API) CD-grade synthetic oil. For the

fuel oil used in the engines at that time, the specification was that the sulfur content was not

to exceed 0.30 percent. In early 1995, the supplier of fuel oil to Calvert Cliffs switched to

fuels with sulfur contents of 0.05 percent or less in order to meet new Environmental

Protection Agency requirements intended to reduce sulfuric acid emissions. With the

reduced amount of sulfur, there would be more unreacted additive in the lubricating oil, resulting in the formation of deposits when some of the oil was bumed. These deposits built

up behind the piston rings, forcing the rings to extrude and come into contact with the

cylinder liner wall, resulting in scuffing.

After the problem was identified, BGE rebuilt the safety-related EDG with new cylinder liners, pistons, and piston rings. On the basis of the findings of the root cause analysis team, the

safety-elated EDG was supplied with a different lubricating oil, which is an API CG-4 grade

mineral-based oil. A series of acceptance tests were then run to validate the root cause.

The safety-related EDG was inspected after test runs totaling about 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> and no

abnormal conditions were found. The station blackout EDG was then refurbished, tested, and inspected, and the results were identical to those for the safety-related EDG.

Another characteristic of synthetic lubricating oil was identified during the review of this event.

Synthetic oils contain diester additives required to improve solubility of oil additives. In diesel

IN 96-67 December 19, 1996 engines with low oil sump temperatures, water may accumulate in the sump because the

temperature is too low to vaporize it. This water might cause hydrolysis of the diesters and

the resulting acids would react with calcium in the additive to form insoluble compounds

(soaps). These compounds may clog filters and degrade performance of a diesel engine.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please refer to the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Kirke Lathrop, Region I

(410) 586-2626 Email: hkl@nrc.gov

Krzysztof Parczewski, NRR

(301) 415-2705 Email: kip@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

KI %&

Attachment

IN 96-67 December 19, 1996 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

96-66 Recent Misadministrations 12/13/96 All U.S. Nuclear

Caused by Incorrect Cali- Regulatory Commission

brations of Strontium-90 Medical Use Licensees

Eye Applicators authorized to use

strontium-90 (Sr-90)

eye applicators

96-65 Undetected Accumulation 12/11/96 All holders of OLs

of Gas in Reactor Coolant or CPs for nuclear

System and Inaccurate power reactors

Reactor Water Level

Indication During Shutdown

96-64 Modifications to Con- 12/10/96 All holders of OLs

tainment Blowout Panels or CPs for nuclear

Without Appropriate reactors

Design Controls

96-63 Potential Safety Issue 12/05/96 All U.S. Nuclear

Regarding the Shipment Regulatory Commission

of Fissile Material licensees authorized

to possess special

nuclear material in

unsealed quantities

greater than a critical

mass

96-62 Potential Failure of the 11/20/96 All holders of OLs

Instantaneous Trip Function and CPs for nuclear

of General Electric RMS-9 power plants

Programmers

96-61 Failure of a Main Steam Safety 11/20/96 All holders of OLs or

Valve to Reseat Caused by an CPs for nuclear power

Improperly Installed Release reactors

Nut

OL = Operating License

CP = Construction Permit

IN 96-67 December 19, 1996 engines with low oil sump temperatures, water may accumulate in the sump because the

temperature is too low to vaporize it. This water might cause hydrolysis of the diesters and

the resulting acids would react with calcium in the additive to form insoluble compounds

(soaps). These compounds may clog filters and degrade performance of a diesel engine.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please refer to the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

original signed by

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Kirke Lathrop, Region I

(410) 586-2626 Email: hkl@nrc.gov

Krzysztof Parczewski, NRR

(301) 415-2705 Email: kipenrc.gov

Attachment: List of Recently Issued NRC Information Notices

Tech Editor reviewed 11/13/96 A*aC4't J-- 6J cZ'JAcC4Lr

DOCUMENT NAME: 96-67.IN *SEE PREVIOUS CONCURRENCES

OFFICE Contacts C/EMCB:DE C/PECB:DRPM D/DRPl l

NAME KLathrop* JStrosnider* AChaffee* TM

KParzewski*

II5 DATE 11/21/96 111/21/96 12/12/96 120Y96 UOicial Kecord Copy r PD C)

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10 A-'J6

IN 96-xx

December xx, 1996 engines with low oil sump temperatures, water may accumulate in the sump because the

temperature is too low to vaporize it. This water might cause hydrolysis of the diesters and the

resulting acids would react with calcium in the additive to form insoluble compounds (soaps).

These compounds may clog filters and degrade performance of a diesel engine.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please refer to the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Kirke Lathrop, Region I

(410) 586-2626 Email: hkl@nrc.gov

Krzysztof Parczewski, NRR

(301) 415-2705 Email: kip@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

Tech Editor reviewed 11/13/96 DOCUMENT NAME: G:JRT\EDG.INS *SEE PREVIOUS CONCURRENCES

OFFICE Contacts C/EMCB:DE C/PECB:DRPM

KLathrop* JStrosnider* AChaffee TMzinl

NAME

KParzewski* lI _

DATE 11/21/96 11/21/96 1.Vlt/96 124096 MIciaal Kecora C.opy

M  ;&M-.)

rAc0

4 IN 96-xx

November xx, 1996 abnormal conditions were found. The station blackout EDG was then refurbished, tested and inspected, with identical results as the safety-related EDG.

Another undesirable characteristic of synthetic lubricating oil was identified

during the review of this event. Synthetic oils contain diester additives

required to improve solubility of oil additives. In diesel engines with low

oil sump temperatures, water may accumulate in the sump because the temperature

is too ow to vaporize it. This water may cause hydrolysis of the diesters and

the resulting acids react with calcium in the additive to from insoluble

compounds (soaps). These compounds may clog filters and degrade performance of

a diesel engine.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please refer to

the technical contact listed below or the appropriate Office of Nuclear Reactor

Regulation (NRR) project manager.

Thomas T. Martin, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Kirke Lathrop, RI

(410) 586-2626 Internet:hkl@nrc.gov

Krzysztof Parczewski, NRR

(301) 415-2705 Internet:kip@nrc.gov

Attachment:

1. List of Recently Issued NRC Information Notices

Tech Editor reviewed 11/13/96 47 DOCUMENT NAME: G:\JRT\EDG.INS 1 OFFICE Contacts C/EMC E .DC/PECB:DRPM D/D

___

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__

KLathro'p/A'

KParzewsk iV F._

AChaffee

_ _ _ _ _ _ _

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_ _ _ _

DATE 11/h3/96 11/P.J/96 11/ /96 1+/-/93/96 Official Record Copy

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