ML13150A171
| ML13150A171 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/19/2013 |
| From: | Lin A Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation |
| Warren Lyon | |
| References | |
| Download: ML13150A171 (6) | |
Text
Loss of Core Cooling Loss of Core Cooling During RCS Mid-Loop on April 10, 1987 Resulted in RHR Pump Cavitaion Resulted in RHR Pump Cavitaion NRC Meeting On Vortexing A
il 18 2013 Anderson Lin Diablo Canyon Power Plant April 18, 2013 y
(805) 545-4286 Axle@pge.com
RCS / RHR Suction Layout RCS / RHR Suction Layout
- Hot Leg centerline 1070
- Hot Leg centerline 107 0
- Bottom of S/G Inlet 108-2
- Bottom of the 14 RHR suction inverted U high point 106-11" 1082 107 1082 10611 Fr = 1.0 Fr 1.0
Event on April 10, 1987
- First Unit 2 Refueling
- 2043 An engineer open a containment penetration valve for local leak rate testing penetration valve for local leak rate testing which resulted draining the RCS inventory 2123 RHRP 2 2 it t d th h t ff
- 2123 RHRP 2-2 cavitated, then shutoff.
RHRP 2-1 started, cavitated, then secured
- 2203 Vented both RHR pumps
- 2241 Refilled from RWST
- 2254 RHRP 2-2 restarted successfully
RCS / RHR Suction Layout 10611 Gas Accumulation at the high point 10611 1066
RCS / RHR Suction Layout 10611 106 11 1066 Once the high point siphon was broken, its downstream water was pump out by the pump
Current RCS Vacuum Refill Figure 1: Unit 2 Lowest Allowable RCS Vacuum Pressure (with Assumed Uncertainties)
RVLIS & UT @ 1078 4.0 120 Indicated Operating Range 3.0 3.5 e (psia) 115 110 105 100 2.5 RCS Pressure 95 90 85 80 70 75 2.0 70 1.5 1300 1325 1350 1375 1400 1425 1450 1475 1500 1525 1550 1575 1600 1625 1650 1675 RHR Indicated Flow rate (gpm)
Fr = 0.44 Fr = 0.57