05000409/LER-1983-001, Forwards LER 83-001/03L-0 & Updated LER 82-020/03X-1. Detailed Event Analysis Encl

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Forwards LER 83-001/03L-0 & Updated LER 82-020/03X-1. Detailed Event Analysis Encl
ML20204F560
Person / Time
Site: La Crosse File:Dairyland Power Cooperative icon.png
Issue date: 04/21/1983
From: Linder F
DAIRYLAND POWER COOPERATIVE
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20204F564 List:
References
LAC-9042, NUDOCS 8305020146
Download: ML20204F560 (3)
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LER-2083-001, Forwards LER 83-001/03L-0 & Updated LER 82-020/03X-1. Detailed Event Analysis Encl
Event date:
Report date:
4092083001R00 - NRC Website
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text

. ..

D DA/RYLAND h [k COOPERAT/VE P.O BOX 817 2615 EAST AV SOUTH

  • LA CROSSE. WISCONSIN 54601 (608) 788-4000 April 21, 1983 In reply, please refer to LAC-9042 DOCKET No. 50-409 Mr. James G. Keppler, Regional Director U. S. Nuclear Regulatory Commission Directorate of Regulatory Operations Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137

SUBJECT:

DAIRYLAND POWER COOPERATIVE LA CROSSE BOILING WATER REACTOR (LACBWR)

PROVISIONAL OPERATING LICENSE NO. DPR-45 REPORTABLE OCCURRENCE No. 83-01

REFERENCES:

(1) LACBWR Technical Specifications, Section 6,.9.1.9.c (2) LACBWR Technical Specifications, Section 4.2.2.14 I

Dear Mr. Keppler:

In accordance with Reference 1, this is to inform you of observed inadequacies in the implementation of administrative or procedural controls which reduced the degree of redundancy provided in a reactor protective system.

Reference 2 states that the high pressure core spray system shall provide water to the fuel elements whenever a reactor low water level scram is generated, except at times during which the reactor vessel head is removed, during injection of boron solution, or during performance of specified tests.

l At 0220 on March 25, 1983, a reactor low water level scram occurred. The operators observed that the 1A High Pressure Core Spray (HPCS) Pump started and supplied water to the reactor, but the IB HPCS Pump was not running.

Troubleshooting demonstrated that the breaker would trip open almost yjf', - immediately after it was closed due to an erroneous ground fault indication.

1 Inspection revealed that a current transformer (CT) in the trip device had been installed backwards. This condition resulted in the trip setpoint being reached when the IB HPCS pump motor was loaded.

8305020146 830421 iDRADOCK05000g; APR 251983 WP-6.8 g L

Mr. James G. Keppler, Regional Director April 21, 1983 U. S. Nuclear Regulatory Commission LAC-9042 A review of maintenance records showed that the CT had probably been improperly installed during the preventive maintenance performed on the breaker August 31, 1982. The pump had been successfully run approximately 38 times since the preventive maintenance, but the highest reactor pressure during these runs was about 57 psig. The motor current required at the lower reactor p'ressures was not sufficient to cause the breaker ground fault trip setpoint to be reached, while the additional motor current needed with the reactor at operating pressure did cause the breaker to trip due to the improperly installed CT.

The ground fault trip devices on other Allis Chalmers LA 600A breakers in the

! Diesel Building 480V Essential Switchgear were checked. The CT's were properly installed in the other breakers. The reversed CT in the IB HPCS pump breaker trip device was reinstalled correctly. The IB HPCS pump was satisfactorily tested.- Included in the testing was verification that the pump would start on a low water level signal.

I&E Procedure No. 74-06, " Maintenance Inspection of 480V Breakers" is being

, revised to include a check of the CT polarity before reinstalling the breaker 1

following maintenance. This action should prevent reoccurrence of this incident.

f The possibility of removing the ground fault trip device was examined. Since the ground fault trip device (with a setpoint of 40A, 50% of overload setpoint) in the LA 600A breaker functions as a protector, not an interrupter, it was decided to maintain the ground fault protection.

A Licensee-Event Report (

Reference:

Regulatory Guide 1.16, Revision 4) is enclosed for this incident. In addition, an updated LER is enclosed for RO ,

82-20.

If there are any questions, please contact us.

Very truly yours, DAIRYLAND POWER COOPERATIVE

/$$$

Frank Linder, General Manager FL:LSG:eme Enclosures cc: Document Control Desk Institute of Nuclear Power Operations NRC Resident Inspector WP-6.8 . . . - - . - - - - - . _ . . - _ . - - .. . . _ - - . - . ~ - , - ,-- . - . - -.

a Mr. James G. Keppler, Regional Director April 21, 1983 U. S. Nuclear Regulatory Commission LAC-9042 Distribution List For Reportable Occurrence No-83-01 SRC: Thie Levine Manion Gasser Milos Taylor Steele Ross Tremmel Marose Nestingen ORC (Ltd): Parkyn Nowicki/ Gray Rybarik/Lange <

Brimer Zibung Towsley Raffety/Bronk Goodman Boyd Kelley/SS (2)

Wery FILES: R-Sh N-10 T-Sn Rdg T.L. R0 Notebook NRC Resident Inspector INP0' Records Center

! Suite 1500 1100 Circle 75-Parkway Atlanta, Ga. 30339 Document Control Desk (1)

U. S. Nuclear Regulatory Commission Washington, D. C. 20555 (3 to Keppler)

WP-6.8

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