ML20168A553
| ML20168A553 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1975-062-00 | |
| Download: ML20168A553 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
104817 Date:
July 29, 1975
Title:
All ADS Valves Inadvertantly Opened at Hatch 1 The failure sequence was:
- 1. The HPCI system was found to be inoperable.
This required surveillance on the ADS system.
- 2. Due to improper use of procedures all the ADS valves were inadvertently opened for 90 seconds.
- 3. The valves were shut by the operator and RCIC was used to recover the reactor water level.
Corrective action:
- 1. All relief valve piping was inspected.
- 2. The procedures were rewritten.
Design purpose of failed system or component:
No component was failed.
Unavilablit of ystm pe WAH 140:*
Unavailability of systoemt per WASH 1400:-
Unavailabilities are in units of per demand D-1.
Failure rates are in units of per hour HR7 1.
Due to HPCI Inoperability, All ADS Valves Were Inadvertently Operator Closes RCIC Provides Inadequate Potential ADS Surveillance was IOpened Due to Inproper Use of ADS Valves Core Cooling Severe Underway Surveillance Procedures Core Damage No No, LPCI/CS operable No, LPCI/CS operable No NSIC 104817 -
Actual Occurrence of All ADS Valves Opened Inadvertently at Hatch 1
Inadvertent ADS Reactor Operator Closes ADS RCIC/HPCI ADS Valves LPCI/CS Long Term Initiation Scram Valves Above LPCI/CS Adequate Success-Success Core Cool-Operating Pressure fully ing Re-opened Potential Severe Core Damage No Ye!
NSIC 104817 -
Sequence of Interest for all ADS Valves Opened Inadvertently at Hatch 1
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER: 104817 DATE OF LER:
August 8, 1975 DATE OF EVENT: July 29, 1975
ýYSTEM INVOLVED:
ADS COMPONENT INVOT. -nt Valves CAUSE:
Operator Error SEQUENCE OF INTEREST:
Inadvertent ADS Actuation ACTUAL OCCURRENCE: All ADS valves inadvertently opened REACTOR NAME: Hatch 1 DOCKET NUMBER:
50-321 REACTOR TYPE:
BWR DESIGN ELECTRICAL RATING: 777 itWe REACTOR AGE:
0.96 yr VENDOR:
General Electric ARCHITECT-ENGINEERS:
Southern Services OPERATORS:
Georgia Power LOCATION:
1L miles-North of Baxley, GA DURATION:
N/A PLANT OPERATING CONDITION:
84% power SAFETY FEATURE TYPE OF FAILURE:
(a) inadequate perfornja.ce; (b) failed to start; (c) made inoperable; W(d) inadvertent operation DISCOVERY METHOD:
operator error during surveillance testing COMMENT: