ML20078A267
| ML20078A267 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/06/1983 |
| From: | Diederich G COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 8309230005 | |
| Download: ML20078A267 (2) | |
Text
/^N Commonwealth Edison 4
[
-') LaSalle County Nuclar Stition r
7 Marseilles, Illinois 61341
$- g Rural Routa #1, Box 220 o
( j-y Telephone 815/357 6761 September 6,1983 FihNCIPAL STAFF RA N dNF 1/
0/RA \\ :3CS /
A /R A V;g CPRP
$0 Zim
/%N James G. Keppler din 5F/
\\
Regional Administrator DE /
K Region 111 MI/
\\
U.S. Nuclear Regulatory Commission 9L FILE
)
799 RooseveIt Road Glen Ellyn, IL 60137
Dear Sir:
This Special Report is being submitted in accordance with LaSalle County Nuclear Station Technical Speci fication 3.5.1.1, concerning ECCS actuation and injection into the reactor coolant system.
On July 18,1983, the -22 VDC power supply to the EHC system was lost due to tioubleshooting being done on the EHC system. The loss of the -22 VDC supply caused feedback to the Bypass Valve Position Unit to be lost. This loss of feedback caused all five main turbine bypass valves to go open caus-Ing alterations in reactor water level which caused the following trips:
a.
Motor Driven Reactor Feedwater Pump high reactor water level trip.
High level was due to swell from sudden opening of the bypass
- valves, b.
Reactor Portector System actuation at low reactor water level,
+12.5".
The drop in level was due to loss of the MDRFP.
c.
HPCS, RCIC, and PCIS initiations at low reactor water level,
-50".
HPCS and RCIC pumps restored reactor pressure vessel level. Upon reactor water level restoration the HPCS pump was secured and the RCIC pump was used to control level.
The total accumulated actuation cycles of the HPCS system into the reactor coolant system is three cycles to date. The individual fatigue usage factor for the HPCS nozzle following the HPCS initiation of July 18, 1983 has been determined to be 0.01428 The total HPCS nozzle fatigue usage factor as of July 18,1983 is 0.043973.
8309230005 030906 PDR ADOCK 05000373 SEP 19 gy g,f eDn tj0
0 e
s.
If there are any questions concerning this Special Report, contact J Renwick, LSCS Technical Staf f Supervisor.
G. J. Diederhch p
- Superintendent g
i LaSalle County Station GJD/GW/rg Encl.
cc:
Director of Inspection & Enforcement Director of Management Information & Program Control U, S. NRC Docunent Managenent Branch INPO-Records Center File /NRC l
i t
t i
[
.m.._