ML20168A463
| ML20168A463 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1977-026-00 | |
| Download: ML20168A463 (4) | |
Text
PRECURSOR DESCRIPTION AND DATA NSIC Accession Number:
124222 Date:
March 28, 1977
Title:
Six Main Steam Relief Valves Fail to Lift Properly at Duane Arnold The failure sequence was:
- 1. During bench testing of six main stean relief valves failed to lift at the required pressure., four failed to open and the renamning two lifted at elevated pressures.
Corrective action:
The problem was being investigated., however at the time of this report the cause hadn't been resolved.
Design purpose of failed system or component:
The steam relief valves allow for pressure control.
Unavailability of system per WASH 1400:
Unavailability of component per WASH 1400:
- 1. 0 x 10-5./D Unavailabilities are In units of per demand D-1.
Failure rates are In units of per hour HR-1.
Bench Testing of 6 Main Four Valves Failed to Open Steam Relief Valves Was and Two Opened at Elevated Underway Setpoipts Potential Severe Core Damage No, refueling outage No NSIC 124222 -
Actual Occurrence of Six Main Steam Relief Valves Fail to Lift Properly at Duane Arnold
Loss of Reactor RCIC/HPCI Feedwater Subcritical
Response
Flow Adequate Automatic Depressurization System Operates LPCI or Long Potential CS Response Term Severe Adequate Core Core Cooling Damage No Yes No Yes Yes Yes Yes Sequence No.
2 3
5 6
NSIC 124222 -
Sequence of Interest for Six Main Steam Relief Valves Fail to Lift Properly at Duane Arnold
CATEGORIZATION OF ACCIDENT SEQUENCE PRECURSORS NSIC ACCESSION NUMBER:
124222 DATE OF LER:
April 2, 1977 DATE OF EVENT:
March 28, 1977 SYSTEM INVOLVED:
ADS COMPONENT INVOLVED:
Relief Valves CAUSE:
Unknown SEQUENCE OF INTEREST:
LOFW ACTUAL OCCURRENCE:
Six Main Steam Relief Valves Fail to Lift Properly at Duane Arnold.
REACTOR NAM4E:
Duane Arnold.
DOCKET NUMBER:
331 REACTOR TYPE:
BWR DESIGN ELECTRICAL RATING:
.821 lMWe REACTOR ACE:
3.0 yr VENDOR:
G.E.
ARCHITECT-ENGINEERS:
Bechtel OPERATORS:
Iowa Electric Power and Light LOCATION:
Cedar Rapids, Iowa DURATION:
4883 (a) hours PLANT OPERATING CONDITION: 0 SAFETY FEATURE TYPE OF FAILURE:
(al inadequate performance; (b) failed to start; 0
made inoperable; (d) ___________
DISCOVERY METHOD:
Surveillance Testing COMMENT:
Four valves failed to open during bench test.