ML18092B435

Responds to Violations Noted in Insp Repts 50-272/86-23 & 50-311/86-23.Corrective Actions:Attachment B-2 Revised to Correct Misinterpretation of Grease Clogged Drains.Revised Attachment B-2 Encl

ML18092B435
Person / Time
Site:	Salem
Issue date:	02/13/1987
From:	MCNEILL C A Public Service Enterprise Group
To:	HEISHMAN R F NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
GL-86-015, IEB-84-44, NLR-N87017, NUDOCS 8702260252
Download: ML18092B435 (7)

See also: IR 05000272/1986023

Text

' . * Corbin A. McNeill, Jr. Public Service Electric and Gas Company Public Service Electric and Ga? Company P 0. Box236. Hancocks Bridge. i\JJ 08038 609 339-4;300

V:ce Pres*cen:

• February 13, 1987 NLR-N87017

United States Nuclear Regulatory

Commission

Document Control Desk Washington, DC 20555 Attention:

Mr. Robert F. Heishman, Chief Vendor Programs Branch Division of Quality Assurance

Gentlemen:

Vendor and Technical

Training Center Programs Off ice of Inspection

and Enforcement

NRC INSPECTION

50-272/86-23

AND 50-311/86-23

REVISED RESPONSE TO INSPECTION

REPORT SALEM

STATION DOCKET NOS. 50-272 AND 50-311 meeting was held on

3, 1987 at NRC Region I to discuss our responses

to those Salem EQ inspection

findings subject to the 10CFR50.49

enforcement

criteria delineated

in Generic Letter 86-15. During the meeting, NRC staff representatives

were notified of changes to our previous responses (dated November 7, 1986 and December 15, 1986) to the subject inspection

report. Those changes are being formally submitted

by this letter and its attachment.

We first request that our previous response to Potential

Enforcement/Unresolved

Item 50-272/86-23-03:

50-311/86-23-03

regarding

the qualification

of Rockbestos

EPR and Coaxial cahle be withdrawn.

An in-depth review of our November 7_, 1986 response to this finding was performed

by PSE&G prior to the meeting at NRC Region I. The results of the review determined

that although PSE&G EQ personnel

were knowledgeable

of the additional

tests which substantiated

the results of the questionable

Rockbestos

test reports noted in IE Information

Notice 84-44, these test reports had not been formally analyzed and referenced

in the Rockbestos

EQ file. As such, the inspection

finding in this area is not disputed.

The review of the response to Potential

Enforcement/Unresolved

Item 50-272/86-23-04:

50-311/86-21-04

also uncovered

certain *discrepancies

in the information

presented

with regard to the Limitorque

gear case grease reliefs. Correction

of these

Q * . ' * * Document Control Desk 2 2/13/87 discrepancies

does not alter our position that tha grease reliefs were not required for the operability

of the Limitorque

operators

in containment

under Salem plant-specific

post-accident

conditions.

The statement

in Attachment

B-2 to the November 7, 1986 letter with regard to the reasons for the clogging of the drains in FIRL Test Report F-C3441 were misinterpreted

in that the drains were clogged with grease which had come out of the grease relief valve after the flooding of the test chamber. The grease actually came out of the relief valve prior to the flooding of the chamber. The grease used was not identified.

This misinterpretation

does not alter the overall analysis performed

on the subject item and has been corrected

in the "Revised Attachment

B-2." The grease referred to in the November 7, 1986 submittal, Mobil Grease 28, is used in the intermittent

gear box (not the main gear box) and is valid for that application.

The intermittent

gear box has no grease relief valve. The grease used in the main gear box is EXXON Nebula EPO or EPl. Although it is not a synthetic

lubricant

like Mobil

28, it has been evaluated

and the results indicate that it would perform in a manner similar to that presented

for Mobil Grease 28. Analysis of the in-containment

post-accident

conditions

with respect to the warming of the gear box and the subsequent

expansion

of the grease have indicated

that appreciable

expansion

would not occur and that the

compartment

would not be breached.

Also, the statement

in the November 7, 1986 submittal

with regard to "appreciable

expansion" of the grease only occurring

afier reaching the dropping point should not have been interpreted

to mean that no expansion

occurs until the dropping point is reached. It is understood

that expansion

will begin to occur upon the initial warming of the grease. To avoid any confusion, this statement

has been withdrawn.

A Revised Attachment

B-2 is provided with this letter. Please contact Mr. Bruce Preston at 609-339-5129

with any questions

you may have* Your cooperation

in this matter is appreciated.

Sincerely, Attachment

Document Control Desk C Mr. D. C. Fischer Licensing

Project Manager Mr. T. J. Kenny Senior Resident Inspector

Dr. T. E. Murley Regional Administrator

Region I 3 2/13/87 -I

Revised Attachment B -2 A potential

enforcement

item was identified

by the NRC related to the absence of gear box grease reliefs on Limitorque

actuators

located in containment.

The

is that the gear box grease reliefs must be provided in the plant installation

since they were installed

in the Limitorque

actuators

subjected

to the LOCA/MSLB

test simulation.

It is verbally stated by Limitorque

that the relief valve provides for relief of grease and the pressure build-up which occurs due to thermal expansion

at prolonged

elevated temperatures.

However, Limitorque

also states in Report

pages 14 and 15, that "Limitorque

actuators

for Nuclear Plant applications

are designed to operate in normal and accident conditions

without depending

on absolute sealing. In fact, the ambient is not absolutely

restricted

from entering the actuator.

The seals, are of no importance

for qualification

and, therefore, require no consideration

for the qualification".

Mr. J. Drab of Limitorque

stated in a telephone

conversation

with Ms. B. Horst of PSE&G on April 9, 1986, as documented

in the Record of Verbal Discossions, "They are not an EQ

and their absence does not adversely

affect the qualification

status of Limitorques", Mr. Drab and Limitorque

have subsequently

refused to issue this statement

in a signed letter. In FIRL test report F-C3441 prepared for Limitorque (used in their BWR Containment

Report-60376A), it was identified

that flooding of the test chamber occurred from a build up of steam condensate

when the test chamber condensate

trap became clogged. This was attributed

to a grease build up in the trap caused by grease that had evidently

come out of the relief valve during the test. The test was stopped during the fifth day. Prior to the test discontinuation, the specimen had been subjected

to 2, three hour transients

at +340°F, 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> at +320°F and 4 1/2 days at +250°F. The Salem plant temperature

profile for a Main Steamline

Break (MSLB) shows a peak temperature

of 347°F for 72 seconds, droppinq to approximately

260°F in less than 5 minutes. For a LOCA, a peak temperature

of 268°F is reached and maintained

for 12 1/2 minutes. Within 30 minutes the temperature

will fall below 250°F. Each of these accidents

produces a peak pressure of 43.2 psig for 170 minutes. Therefore, an external positive pressure is maintained

for the duration of the temperature

transient

minimizing

the pressure differential

due to possible internal pressure buildup. da8/l

'< ' .. The Superheat

Temperature

Test Report #B0027 was performed

to determine

the internal temperatures

of components

in the Limitorque

valve actuators

due to superheat

ambient temperatures.

It illustrates

that exposure of the actuator to high environmental

temperatures

for short durations

of time will not raise internal unit temperatures

to an equal state. It was demonstrated

by analysis that an*ambient

temperature

of 492°F in excess of 17 minutes would only result in a maximum internal temperature

of 315°F for the electrical

switch compartment

components

and motor windings.

Actual testing indicates

that an ambient temperature

of 385°F was reached at 186 minutes and at this time the temperature

inside the motor was only 282°F. It can therefore

be concluded

that the effects of high ambient temperatures

over a short time period will not result in excessively

high internal temperatures.

As such, excessive

internal pressure will not result. The grease utilized for lubrication

of the intermittent

gear box in the Limitorques

at Salem is Mobil Grease 28. This. is a synthetic

lubricant

exhibiting

high pressure characteristics

at temperatures

in excess of 350°F. This grease has a dropping point of approximately

500°F, which precludes

its changing to a liquid state even under superheat

conditions.

The main gearbox utilizies

a calcium complex base grease manufactured

by Exxon and known as Nebula EPl (or EPO). This grease can be used for applications

up to 400°F, it contains an Extreme Pressure (EP) additive to help increase the film strength of the oil, and has a dropping

of approximately

500°F. The EPl grease exhibits similar characteristics

to the Mobil 28 grease and both types of grease are approved by Limitorque

for in-containment

applications

in the operators.

In Test Report B0003, an actuator containing

Nebula EPl gearbox grease was exposed to a sustained

temperature

of 250°F for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Grease relief valves were not installed

on this actuator as Limitorque

evidently

determined

that exposure to 250°F and 25 psig during an accident test was not sufficient

to justify their usage ** The test unit actuator was a SMB-0 type, which is rather small, containing

approximately

9.5 pounds of gearbox grease. Larger actuat9rs

contain up to 75 pounds of grease (SMB-4 or 5 type). Given the small size of the test unit, it can be deduced that maintaining

the temperature

at 250°F for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> will bring .the entire unit to therma1 equilibrium, including

the gearbox grease. It can therefore

be determined

that EPl type grease can be heated to 250°F and will not expand to any degree that would require the use of a grease relief on the actuator.

da8/2

... * By utilizing

the Salem accident profile for temperature

and pressure for worst case Main Steam Line Break (MSLB) and Loss-of -Coolant Accident (LOCA), it can be determined

by analysis that exposure to either condition

inside containment

will not cause the gearbox grease to exceed 250°F. This is due to the fact that the maximum LOCA temperature

of 268°F is reached in approximately

4 minutes following

the start of the accident, after which the temperature

slowly begins to decrease.

Thirty minutes following

the start of the event the temperature

has fallen below 250°F. As is evident, the time duration is not sufficient

to heat the grease above 250°F. During the MSLB event, a maximum temperature

of 347°F is *reached in approximately

100 seconds. This temperature

is maintained

for 72 seconds, after which the temperature

rapidly begins to decrease.

Thirty minutes following

the start of the event the temperature

falls below 250°F. Again the time duration at the temperature

above 250° is not sufficient

to heat the grease above 250°F. The characteristics

of the grease would be a factor in determining

the necessity

of grease reliefs on the gear case housing. Since the greases utilized during the qualification

tests were not identified, a correlation

of actual parameters

cannot be made. However, a temperature

resistant

grease such as the Nebula EPl appears to have been used. As proven by test, the internal temperature

of the operator, even un-der superheated

ambient conditions, would not cause the internal temperature

to exceed saturated

conditions.

This temperature

is well within the design limits of the specified

grease and would not be cause for it to exhibit appreciable

expansion.

A pressure buildup sufficient

to breach tbe switch compartment

is not possible under the Salem Station postulated

accident conditions

and therefore

grease relief plugs are not required to maintain operability

of the valve. It should be noted that PSE&G's position was, and still is, that a determination

to not use grease reliefs was made from all known and available

information.

Based on the verbal information

from Limitorque, the Salem PWR specific accident profiles and knowledge

of the data in the test report; it was determined

that the grease relief valves were not necessary;

would not prevent the valves from performing

their safety function;

and their absence would not be in violation

of the qualification

status of the actuators.

da8/3

. For information

purposes, at the time of the inspection, there *were 7 in-containment

class lE actuators

in Salem Unit 1 that were identified

by Station QA personnel

as not having grease . relief valves. Salem Unit 2 had grease relief valves installed

on all in-containment

actuators.

In accordance

with the recommendation

to. utilize grease reliefs as good engineering

practice, grease reliefs are now installed

on all in-containment

actuators

at Salem. da8/4