ML20168A730
| ML20168A730 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1979-068-00 | |
| Download: ML20168A730 (4) | |
Text
November 28, 1979 Safety Injection Pump Fails at Salem 1 ure sequence was:
the reactor in cold shutdown, High Pressure Safety Injection Pump No. 12 started to refill an accumulator.
pump breaker tripped when the pump started.
stigation revealed the impeller locknuts on the pump had loosened, lting in worn spacer sleeves and a bent impeller.
her investigation revealed the impeller lock nuts on the other High sure Injection Pump were also loose, as were the lock nuts on one pump he other unit.
ve action:
damaged rotating element was temporarily replaced with one from a pump ther unit. The lock nuts were secured using Locktite.
urpose of failed system or component:
high pressure injection pumps provide the source of high pressure injec-for loss of coolant accident mitigation.
bility of system per WASH 1400:
- High Pressure Injection (2 of 3 pumps):
1.2 x 10 2 bility of component per WASH 1400:
- Pump, failure to start: 1 x 10 3 '/D availabilities are in units of per demand D-1 Failure rates are in per hour HR-1 .
Reactor in No. 12 Safety Injec- Impeller Lock Nuts Potential Cold tion Pump Fails to Loose on No. 11 Severe Shutdown Deliver Flow Due to Safety Injection Core Damage Loose Impeller Lock Pump Nuts Resulting in Worn Spacer Sleeves and a Bent Impeller Shaft
¶ No No
- reactor in cold shutdown plus no LOCA No NSIC 154286 - Actual Occurrence for Safety Injection Pump Fails at Salem 1
LOCA Trip Feedwater and Secondary Heat Removal
{Injection Pressure Recirculation and LPR/HPI C2ross-Connect Severe Core Damage No.
2 3
4 5
6 7
NSIC 154286 - Sequence of Interest for Safety Injection Pump Fails at Salem 1
SION NUMBER: 154286 R: December 20, 1979 ENT: November 28, 1979 OLVED: High Pressure Injection INVOLVED: High Pressure Injection Pumps ose Impeller Lock Nuts INTEREST: Small LOCA URRENCE: Failure of ome pumip to deliver flow and loose lock nuts on the other pump while in cold shutdown.
E: Salem 1 ER: 50-272 E: PWR TRICAL RATING: 1090 MW,
- 3.0 yr stinghouse NGINEERS: PSE&G Public Service Electric & Gas Co.
20 niles south of Wil-mington, DE 360(a) hours TING COND)ITION: cold shutdown URE TYPE OF FAILURE: (a) inadequate performance; (b) failed to start; C>made inoperable; (d) ___________
ETHOD: pump breaker tripped after pump was started.
igh Pressure Injection Pump No. 22 for Salem 2 was also found to have loose impeller locknuts. Pump 21 for Salem 2 was found to have its lock nuts secured with setscrews. The pump vendor recommended against this and the pump rotating elements were returned to the pump vendor for rework.