ML101260148

April 2010 River Bend Station, NRC Initial License Examination Analysis, April 21, 2010

ML101260148
Person / Time
Site:	River Bend
Issue date:	04/21/2010
From:	NRC Region 4
To:
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Download: ML101260148 (3)

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April 2010 River Bend Station NRC Initial License Examination Analysis April 21st , 2010 Question Analysis 8 Both C & D are incorrect because of the stable lAS Question Valid pressure with only 1 IAS/l SAS compressor in operation.

At 113 psig SAS-AOV134 will open, if pressure lowered to 110 psig then SAS-AOV133 would close.

10 A fuel bundle is 14 feet long in order to clear the RPV Question Valid flange during refueling operations with 8.5 feet of water shielding above would require 23 feet above the flange.

The flange at +200inches and the TAP at -162 converts to a little over 30 feet from TAP to flange.

12 SRV initial opening pressure is 1133 psig, at that Question Valid pressure the superheated steam at Atmospheric pressure is -285 degF, at 450 psig the temperature is -330 degF.

13 Suppression Pool level of 19' 11" and 140 degF lie within Question Valid the SAFE region of EOP-002. HCTL below 800 psig.

SOP-0031 P&L 2.5 has several statements about exceeding 5800 gpm Service Water Flow (Normal or Standby). P&L 2.4.5 states that shell side flow can not exceed 5550 gpm which is the RHR flow side.

20 Reactive power (VAR) required is a function of the load Question Valid on the grid. With the loss of other units the same reactive component is still required and must be supplied by the remaining unit(s). So reactive load supplied by RBS will increase. In Auto the voltage regulator will attempt to maintain the same generator terminal voltage, to supply a higher output voltage, the magnetic field in the stator must be strengthened. To raise the magnetic field the current must be raised.

28 With control transferred to the Remote Shutdown panel Question Valid all logic circuits in the MCR would be bypassed. All actions would be manual and would require operator action to change the configuration.

29 CCP-MOVI6A provides cooling to the Safety Related Question Valid

'A' Loop components for RHR 'A' pump and Fuel Pool Cooling Hx 'A', RWCU and Recirc pumps would not be affected.

April 2010 River Bend Station NRC Initial License Examination Analysis April 21 st ,2010 32 In Mode 3, you would be in the Operating section of Question Valid Tech. Spec. so B & D are incorrect, since this involves a single component supplied by a single breaker the remainder of the bus can met it operability requirements, only the individual HPCS pump would be inoperable.

36 108/125 generates an IRM Alarm Upscale signal which Question Valid generates a Rod Block in RC&IS. A signal of 120/125 is required to generate a RPS trip signal.

37 Only SRM Rod block signals are INOP, Downscale Question Valid

<3cps, Upscale>lOE5cps, and Retract permit <100cps.

Of the four SRM only 3 are on scale/operable. None of the 3 operable are above the Upscale trip or below the downscale trip. While the SRM's are not fully inserted the rod block is bypassed when the IRM's are range 3 or above. Placing the SRM switch in STANDBY removes the reference signal into the trip unit causing a Rod Block.

38 P680 and Back panel indications are supplied by a Question Valid common power source. The APRM cabinets are all supplied by 120VAC RPS power as is the RPS trip Logic. The APRM cabinets require 5, 20 & 24VDC which is supplied by a Power supply at the bottom of the APRM cabinet which must be reset to energize after a loss of power.

42 The ADS 'E' subchannel is energized however both Question Valid subchannels A &E are required to energize the Div 1 ADV valve logic. The logic train for the 'A' subchannel is incomplete, A LOCA signal has actuated the High Drywell pressure andlor Levell logic, the Level 3 logic has completed and closed in the only action which has not taken place is timing out of the 105 second timer between the subchannel 'A' logic and the K6A relay coil.

Because the 'E' subchannel is sealed in the Div 1 ECCS Pump Running logic has been made up.

43 In StartuplHot Standby the RPS Hi level signal is Question Valid bypassed by the K24 relay when the mode switch is not in RUN, no scram will result. CNM-FV104 will require manual operation since there is no level input; it is a manual flow control valve. With the Startup Feedwater valve open and able to supply 10% of rated flow the level will raise until something terminates the flow. In this case a high level 8 trip of the Feedwater Pumps

April 2010 River Bend Station NRC Initial License Examination Analysis April 21 st ,2010 47 The UPS has 3 sources of power the DC Battery bank, Question Valid the Rectifier supplied by an AC source and an Alternate AC source supplied thru a conditioning transformer. The AC supplied is the normal source of power to the UPS inverter, with the DC Battery bank operated at a lower voltage, so current flow is from the Rectifier. When the Rectifier is lost the voltage will lower until it is equal to the DC Battery bank at which point the current flow will seamlessly flow from the DC Batteries. The Static Switch only come into play when both the Rectifier and DC Battery sources or the Inverter which is a DC-AC converter fail to provide voltage, at which point the Static switch will transfer to the Alternate AC power source.

48 The correct power supply for E51-MOVF013 is ENB- Question Valid MCC1. ENB-MCCI supplies the power to several RCIC valves. ENB-PNL02A does not supply power to RCIC, and ENB-SWGIB and ENB-CHGRIB are Division 2 49 Normally DC buses are supplied by the Bus DC Charger. Question Valid On a loss of all AC power the loads will be carried by the batteries. Depending on the design load requirements, the Safety Related ENB bus are expected to last 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the non safety related DC bus only 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. If power is not expected back for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> the batteries are expected to be depleted. A Backup supply of DC power to the Buses and/or recharging the batteries will be required.

This function is met with the Station Blackout Diesel Generator supplying an ENB Bus DC charger.

51 Fire Protection headers in the Diesel Generator room Question Valid have temperature activated sprinkle heads, so no flow of water is expected, the valve is better described sa pre-action valve. There is no Diesel Generator trip circuit as part of the Fire Suppression! Detection system.

60 Tech Spec 3.6.1.9 LCO requires both subsystems in Question Valid Modes 1,2, & 3. 50%

67 Unescorted access to the Protected area requires PAT, Question Valid Drug Testing (initial and random) and Psychological testing (Initial MMPI & Behavioral Observation) 73 MON 028 ITEM command is used during STP-OOO-OOOI Question Valid for the operator to read sample No.1 flow. Per SOP-86.