ML20168A721
| ML20168A721 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 06/16/2020 |
| From: | Christopher Hunter NRC/RES/DRA/PRB |
| To: | |
| Littlejohn J (301) 415-0428 | |
| References | |
| LER 1977-002-00 | |
| Download: ML20168A721 (4) | |
Text
arch 9, 1977 Both ANW Pumps Unavailable at Rancho Seco ure sequence was:
the reactor at 100% power, AFW pump P-318 was tested prior to ving ANW pump P-319 from service for breaker maintenance.
pump P-318 was shut down, the manual/overspeed trip was not erly reset. This resulted in both ANW pumps being unavailable seven hours.
ve action:
pump trip was correctly reset, the pump was tested, and returned ce.
urpose of failed system or component:
auxiliary feedwater system provides steam generator cooling in the e maim feedwater system Is unavailable.
bility of system per WASH 1400: *ANW (start + 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />): 3.7 x 10-5 3
bility of component per WASH 1400: *Pump, failure to start: 1 x 10- /D navailabilities are In units of per demand D-1. Failure rates are In 1
per hour HR- .
ctor at AN Pump P-318 Pump P-318 Pump P-3l9 Potential
% Power Tested Prior to Incorrectly Removed From Severe Removing ANW Reset Follow- Service for Core Pump P-319 From ing Shutdown Maintenance Damage Service for Maintenance No - No loss of feedwater plus manual start of P-318 still possible NSIC 123118 - Actual Occurrence for Both ANW Pumps Unavailable at Rancho Seco
No 1 No 2 Yes 3
-Yes 4
.No 5
-No 6
-Yes 7
-Yes 8
-No 9
-No 10
-Yes 11
-Yes 12
-Yes 13 NSIC 123118 - Sequence of Interest for Both AFW Pumps Unavailable at Rancho Seco Use of HPI following failure of AFW not included in operating procedures.
Operator action required for degraded
NUMBER: 123118 March 9, 1977 February 18, 1977 D: Auxiliary feedwater LVED: Auxiliary feedwater pump erly reset mamual/overspeed trip mechanism TEREST: Loss of main feedwater NCE: Unavailability of both auxiliary feedwater pumps while at power Ramcho Seco 312 PWR CAL RATING: 918 MWe 2.4 yr NEERS: Bechtel cramento Municipal Utility District miles SE of Sacramento, California hours G CONDITION: 100% power TYPE OF FAILURE: (a) inadequate performance; (b) failed to start; (9made inoperable; (d)___
OD: operator observation