ML20024C983
| ML20024C983 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 07/08/1983 |
| From: | Linder F DAIRYLAND POWER COOPERATIVE |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20024C978 | List: |
| References | |
| LAC-9195, NUDOCS 8307210253 | |
| Download: ML20024C983 (3) | |
Text
-
m.
~'*
COOPERA T/VE
- P.O. BOX 817 2615 EAST AV SOUTH
- LA CROSSE. WISCONSIN S4601 (608) 788 4 000 July 8, 1983 In reply, please refer to LAC-9195 DOCKET N0. 50-409 Mr. James G. Keppler, Regional Administrator
~
U. S. Nuclear Regulatory Commission Directorate of Regulatory Operations Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137
SUBJECT:
DAIRYLAND POWER COOPERATIVE LA CROSSE B0ILING WATER REACTOR PROVISIONAL OPERATING LICENSE NO. DPR-45 IE INSPECTION REPORT 50-409/83-05
REFERENCES:
(1) NRC Letter, Shafer to Linder, dated June 17, 1983 (2) DPC Letter, Linder to Keppler, LAC-9042, dated April 21, 1983
Dear Mr. Keppler:
This letter constitutes the written statement required in reply to the March 1 through May 15, 1983 Inspection Report (Reference 1), which was received June 21, 1983. The Notice of Violation listed one item of noncompliance.
NRC Item Technical Specification 6.8.1 requires written procedures be established, implemented and mintained covering the activities recommended in Appendix "A" of Regulatory Guide 1.33, Revision 2.
Section 9 of Appendix "A" of Regulatory Guide 1.33, Revision 2, requires procedures for performing mintenance that can affect the performance of cafety-related equipment.
Allis Chalmere instruction mnual for Type IA-600A Breaker states in part, "The tripping transformere on the upper connectors of the circuit breakers are mounted with the polarity mrke facing the breaker panel. The tripping transformer on the lover connector is wunted with the polarity mrk' facing away from the breaker panet".
l WP-6.4 -
8307210253 830715 Jyg pDRADOCK-050000
Mr. James G. Keppler, Regional Administrator July 8,1983 U. S. Nuclear Regulatory Commission LAC-9195 Contm ry to the above, on August 31,1982, m1intenance me performed on the No.1B High Pressure Core Spmy (HPCS) pump breaker per Maintenance Procedure I&E 74-06, Issue "O".
This procedure did not include the Attis Chalmere recommended instruction for proper instattation of current tripping t nneformers and the tower transformer m e instatted backwarde with its polarity mark facing the breaker panet in lieu of facing away from the breaker panet. This improper instattation meutted in the premature tripping of the No.1B HPCS pump breaker during a mactor too mter levet eenm which occurred at 0220 on March 25, 1983.
This is a Severity Level IV violation (Supplement I).
DPC Response Corrective Action Taken and Results Achieved A full account of the circumstances involved in this incident is contained in Reference 2, which was Reportable Occurrence No. 83-01.
The reversed current transformer (CT) in the 1B High Pressure Core Spray Pump breaker trip device was reinstalled correctly. The pump was tested with satisfactory results on March 25, 1983.
The 1A HPCS Pump was operable, started automatically and supplied water to the reactor vessel during the low water level scram on March 25, 1983. Only one pump is required to provide adequate core cooling.
Between August 31, 1982 and March 25, 1983, the IB HPCS Pump had been successfully run approximately 38 times. The highest reactor pressure during these runs was about 57 psig.
The motor current required at the lower reactor pressures was not sufficient to cause the breaker ground fault trip setpoint to be reached.
During the design basis Maximum Credible Accident (MCA) at LACBWR, the reactor and Containment Building pressures are expected to quickly reach about 48 psig.
l As demonstrated by the successful runs of the IB HPCS pump at reactor pressures < 57 psig, a breaker ground fault trip would not have been expected to prevent the pump from running if an MCA had occurred while the current transformer was incorrectly installed.
Thus, both HPCS pumps would have been available for mitigation of an MCA.
l Corrective Action Taken to Avoid Further Noncompliance l
The ground fault devices on other Allis-Chalmers LA-600A breakers in the Diesel Building 480V Essential Switchgear were checked on March 25, 1983. The CT's were properly installed in these breakers.
I&E Procedure No. 74-06,
" Maintenance Inspection of '480V Breakers" was revised to include a check of l.
the CT polarity before reinstalling the breaker following maintenance. The revised procedure was reviewed by the Operations Review Committee and approved by the, Plant Superintendent on April 13, 1983. These actions should preclude reoccurrence of this incident.
WP-6.4~ _
Mr. James G. Keppler, Regional Administrator July 8,1983 U. S. Nuclear Regulatory Commission LAC-9195 Date Full Con.plianca Achieved April 13,1983 If there are any questions, please contact us.
Sincerely, DAIRYLAND POWE COOPERATIVE h
Frank Linder, General Manager FL:LSG:eme WP-6.4 3-
~ ;_ ;*.; g - ; ;_ y.,; ; r. ;,.y, ; s,
s,.
_ ; - _ " ;-.. _ e..
'; q.:. s ;.;;*. ;
..o r_.
- r -
.. -y :..;. -
p
_