05000409/LER-1982-007, Forwards LER 82-007/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-007/03L-0.Detailed Event Analysis Submitted

ML20054G771
Person / Time
Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	06/14/1982
From:	Linder F DAIRYLAND POWER COOPERATIVE
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20054G772	List: 05000409/LER-1982-007, Forwards LER 82-007/03L-0.Detailed Event Analysis Submitted 05000409/LER-1982-007-03, /03L-0:on 820515,during Refueling Outage,Buses 1A & 1B Were Supplied by 1A & 1B Emergency Diesel Generators for 12 Minutes.Caused by Undervoltage Relay Breaker Opened During Troubleshooting of Dc Ground
References
LAC-8349, NUDOCS 8206220285
Download: ML20054G771 (2)

LER-1982-007, Forwards LER 82-007/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
4091982007R00 - NRC Website

text

,.

DlDA/RYLAND [S/((M[COOPERA7/VE

• PO BOX 817 2615 EAST AV SOUTH. LA CROSSE. WISCONSIN 54601

(%8) 7M4%0 June 14, 1982 In reply, please refer to LAC-8349 DOCKET N0. 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 N0. DPR-45 REPORTABLE OCCURRENCE NO. 82-07

REFERENCES:

(1)

LACBWR Technical Speci fi cati ons,

Section 6.9.1.9.b.

(2)

LACBWR Technical Speci fi cat i ons,

Section 4.2.3.2.2.

Dear Mr. Keppler:

In accordance with Reference 1, this report is notification of a procedural inadequacy which led to operation in a degraded mode permitted by a limiting condition for operation.

Reference 2 requires that specified AC electricel buses be operable and energized from sources of power other than a diesel generator, but aligned to an operable diesel generator.

At 0346 on May 15, 1982, with the plant in Operating Condition 5, Refueling, a Reactor Plant 125 V DC Ground Alarm (A9-3) was received.

The annunciator response procedure was followed.

In following the procedure, the undervoltage relay breaker for 1A and 1B 480 V AC Buses was opened.

Opening this breaker caused the 1A and 18 480 V Main Feed Breakers (452 M1A and 452 M1B) to trip.

The 1A and 1B Emergency Diesel Generators started and assumed the essential loads.

The electrical systems were returned to normal at 0358 and the diesel generators were secured.

The Action statement of Reference 2 was followed.

hohk5 20614 R

S 0 000409 WP6 g tg @2

[ L L :u

.o Mr. James G. Keppler, Regional Director June 14, 1982 U. S. Nuclear Regulatory Commission LAC-8349 Although the annunciator response procedure specified that the undervoltage relay breaker should not be opened during plant operation, it did not state what actions would occur if it was opened with the plant shutdown.

Consequently, the diesel generators were brought into operation unexpectedly.

The procedure will be modified to provide more guidance.

The 125 V DC ground was tracked to a position indication limit switch installed on one of the Forced Circulation Pump Discharge Bypass Valves.

As a result of maintenance, moisture had entered the switch. The switch was dried and covered with plastic to prevent reoccurrence.

A Licensee Event Report (Reference:

Regulatory Guide 1.16, Revision

4) is enclosed.

If the_re are any questions regarding this submittal, please contact us.

Ve ry truly you rs,

DAIRYLAND POWER COOPERATIVE hW A

Frank Linder, General Manager FL:LSG:eme Attachment cc:

Document Control Desk U.

S. Nuclear Regulatory Commission Washington, D. C.

20555 NRC Resident Inspector INP0 WP1