ML20003A935

Forwards LER 80-025/03L-0

ML20003A935
Person / Time
Site:	Oconee
Issue date:	01/30/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML16148A406	List: ML16148A405 ML20003A935
References
NUDOCS 8102100091
Download: ML20003A935 (3)

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O DlJKE POWER COMPANY Powen UtJttonwo 422 Socin Cnuncu Sruzer.CRAH14TTz N. C. 2a24a WI L LI Ae4 Q. PA R M E R, J R, s,ec a.cs.oco, rc. c..e c: .c. 7:4 sec. a oove-o=

January 30, 1981 m-4:n Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket No. 50-270

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-270/90-25. This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1.b(2), which concerns operation in a degraded mode permitted by a limiting condition for operation, and describes an incident which is con-sidered to be of no significance with respect to its effect on the health and safety of the public.

Very truly yours,

, & d' William O. Parker, Jr.

JLJ:pw Attachment ec: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Center.

U. S. Nuclear _ Regulatory Commission P.-0. Box 10412 Washington, D. C. 20555 Palo Alto, California 94303 007 s

/I 81020100% Q

O DUKE POWER COMPANY CCONEE UNIT 2 Report Number: R0-270/80-25 Report Date: January 30, 1981 Occurrence Date: December 17, 1980 Facility: Oconee Unit 2, Seneca, South Carolina Identification of Occurrence: High Pressure Injection Pump Inoperable De to Upper Motor Bearing Failure -

Conditions Prior to Occurrenc . -99% FP Description of Occurrence: At 1718 on December 16, 1980, the "2B" High Pressure Injection (HPI) pump was removed from service in order to change the oil, due to increasing temperatures on the upper motor bearing. When.

the oil was changed, an improper oil level was lef t in the top oil pot, thus resulting in the motor becoming inoperable. The 2B HPI pump was de-clared inoperable at 1330 on December 17, 1980. On four consecutive test runs after the oil change, the motor indicated high upper bearing temperatures The inoperability of the 2B.HPI pump constitutes operation in a~ degraded mode per Technical Specification 3.3.1.c(2) and is thus reportable . pursuant to Technical Specification 6.6.2.1.b(2)

Before repair of "2B" HPI Motor on December 18, 1980, numerous problems have been encountered with the temperatures of the upper bearing assembly.

These temperatures were considered to be high to the extent that all other motors operating at the same time were considerably cooler on the upper bearing assembly. The range in temperature has reached as much as 30 to 35 degrees higher than the other operating motors. Upper bearing assemblies, thermocouples, and upper oil pots have been changed on the motor with problems still re-occurring. The pattern seems to be as follows: The temperature. gradually increases over a period of two weeks to a month's time until it is.in the

- 200 F. range. The motor is then shutdown, the oil changed, and then re-started resulting in initial lower upper bearing temperatures for several days followed by the same gradual increase of bearing temperatures again.

As has already been mentioned, thermocouples have been changed and were changed during the last motor repairs. There are no known abnormalities in the bearing assemblies.or in the coolers which remove heat from the upper oil pot. .It should be pointed out that cooling water _ flaw is not as much as the design of the motor calls for; however,.there is no indi-cation that this has-hurt the motors because there are other HPI motors.

which are presently running in this state without these abnormally high upper bearing ter.peratures. Much of the cooling water piping system has been changed to"a different ~ type of metal, but there'still exist some carbon steel pipe in the system. lit is believed that there is rust 11n this pipe' causing restrictions in the cooling water flow and possibly even flaking.to break loose and cause further restrictions. ,As for temperatures now being experienced on this motor, abnormally low cooling water temperatures may be the answer. Present plans. call for a change out of1the existing HPI motor when the spare motor is. finished with its reassembly.

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a DUKE POWER COMPANY OCONEE NUCLEAR STATION Report Number: R0-270/80-25 January 30, 1981 Page 2 Apparent Cause of Occurrence: Sight glasses are different on the different HPI motors. There is no procedure for replacing oil in motors. The level of oil that can actually be seen in the sight glass varies, depending on whether it is an upper or lower pot and with the type of sight glass that is installed. The personnel involved were confused between what the oil levels should be in the upper pot sight and in the lower pot sight glass.

It was revealed that the levels vary not only between the upper and lover -

pots, but also between motors.

The cause of the high upper motor bearing temperatures is not exactly known.

This may be due to restricted cooling water flow.

Analysis of Occurrence: With the unit at full power, Technical Specification.

3.3 requires all three HPI pumps to be operable in the event that emergency core cooling is needed. If one HPI pump is inoperable,Lthe pump must be

~cstored to operability within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or the unit must be reduced to below-00% FP. During the period of the inoperability of the 2B HPI pump, both-the 2A and 2C HPI pumps were operable, as well as all other ECC systems.

In addition, the HPSW was available to supply the coolers if required to do so. The 23 RPI pump was returned to service well within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period allowed. Thus, this incident was of no significance with respect.to safe operation, and the health and safety of the public were not affected.

Corrective Action: The personnel involved have been-instructed not to per-form actions they know are not correct, but-to pursue this with higher levels of management.

This incident will be reviewed by appropriate personnel.

A method clear: to everyone of determining the proper level of oil in sight glasses will be initiated.

The motor will continue to be observed closely by appropriate personnel to insure that the high temperature problem in the upper bearing does not re'CCur.

A station modification to correct the cooling water problem wil1~be completed-

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as soon as possible. The HPI pump motor will be reviewed to-see if standard-ization can be achieved. Depending on the results of the evaluation, other motors will be reviewed.

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