Zach Stubby's Heavy Hitters - Miscellaneous Systems Part 1

Question 1

Safety Chilled Water Loads

Answer 1

→CCW pump room emergency fan coil units
→CCP room emergency fan coil units
→Spent fuel pool heat exchanger and pump room emergency fan coil units. Fan coil units are common equipment. Can be supplied from either unit.
→SI pump room emergency fan coil units
→Containment Spray pump room fan coil units
→RHR pump room emergency fan coil units
→Aux Feedwater pump room emergency fan coil units
→Electrical switchgear area emergency fan coil units*
→Uninterruptable Power Supply (UPS) FCUs (hurricane blowers)-Local HS controlled

Note: All EFCUs will start when their associated equipment starts for any reason except for Electrical switchgear units which start directly from SI or BO

Question 2

Safety Chiller Aux Oil Pump Start

Answer 2

→In auto starts first when chiller demanded to start, 30 secs after oil pump starts the chiller starts
→Oil pump shuts off 45 secs after chiller starts
→Auto starts on chiller trip

Question 3

What Cools Safety Chiller Condensers?

Answer 3

→Safeguards CCW cools condensers
→20-300 gpm
→control valve has an accumulator to continue operation for 30 minutes following loss of air

Question 4

Safety Chiller Auto Starts

Answer 4

→SI
→BO
→Associated Recirculation Pump starts

Question 5

Chiller Trips that do not require manual reset (chiller restarts when problem clears)

Answer 5

→LO chilled water temperature
→LO CCW flow
→LO chilled water flow

Question 6

Safety Chiller Anti-Recycle feature

Answer 6

Safety Chillers provided with “Anti-Recycle” feature that prevents chiller restart for 30 minutes after chiller S/D

bypassed on SI or BO restart

Question 7

Safety Chiller Normal Start Requirements

Answer 7

→Aux oil pump running (chiller won’t start until 30 secs after LO Pump starts)
→Chill Water Pump running
→Anti-Recycle timer timed out

Question 8

Chill Water Recirc Pump Auto Starts

Answer 8

→SI
→BO
→Start of train related CCW Pump
→Only Recirc pump 5 can be controlled from RSP
→300 gpm ea, P/S uEB3-1, uEB4-1

Question 9

Safety Chilled Water Surge Tank Makeup Sources, Which Valves Cycle?

Answer 9

→Partition plate splits out tank at 88% level
→HV-6719 (Demin Water) normally closed, HV-6720 (RMUW) normally open, no automatic operation for either valve
→Train related fill valves LV-6712 and LV-6713 open and closed based on tank level

Question 10

PV-4553/4552 (CCW Flow To Safety Chiller Condenser) Accumulator Sized For?

Answer 10

Control CCW flow to maintain chiller condenser pressure. Valves are air open and an air accumulator is provided which ensures operation for 30 minutes following loss of inst. air.

Question 11

Hot Gas Bypass Valve

Answer 11

Chiller has minimal load during normal ops (ΔT ≈ 10° F), so a hot gas bypass valve is installed to artificially load the chiller to ensure proper circulation of lube oil through system.

Otherwise, lube oil would drain to lower area of evaporator and remain there, starving the rest of the chiller for lubrication.

Works by cycling hot gas from discharge of compressor to evaporator HX.

Question 12

UPS Fan Coil Units
(Hurricane Blowers)

Controls

Answer 12

→locally controlled with manual handswitch
→SI - don’t get shunt tripped, so continue running
→BO - switches remain in start, so restart once power is restored

Question 13

System Limitations Before Compressor Start

Answer 13

→control power to compressor oil heaters must be energized for 12 hrs
OR
→oil temp >107° F for at least an hour
OR
→compressor oil was changed within the last hour

Question 14

Tech Spec 3.7.19

Answer 14

Two safety chilled water trains shall be operable in Modes 1-4

→one train inoperable, restore within 72 hrs or RICT; if not, Mode 3 in 6 hrs, Mode 5 in 36 hrs

→two trains inoperable, LCO 3.0.3 immediately

Question 15

Post Accident Instrumentation Design Basis Accidents: (3)

Answer 15

1. LOCA
2. Main Steam/Feed Line Break
3. S/G Tube Rupture

Question 16

Type A Variables permit the Control Room operating staff to…

Answer 16

→perform the diagnosis specified in the ERGs
→take the specified pre-planned manually controlled actions, for which no automatic control is provided, that are required for safety systems to accomplish their safety function in order to recover from the DBA, and
→reach and maintain a safe shutdown condition

Note: all of the Type A variables are required by the accident monitoring Tech Spec. The other variables may be required by other specifications, but not specifically for accident monitoring

Question 17

How is Post Accident Instrumentation labelled?

Answer 17

→all Category 1 (RG 1.97) instruments have black labels with white lettering, but not all Category 1 instruments are required by TS 3.3.3 (Modes 1-3)
→in other words, all PAM instrumentation (TS 3.3.3) has black labels with white lettering and are Category 1
→there are additional instruments that are category 1 and have a black label with white lettering

Question 18

List Type A Post Accident Instrumentation (14 items) and review others.

Answer 18

Question 19

Adverse Containment Values

Answer 19

→containment pressure >5 psig, or
→containment radiation >10^5 R/hr, or
→integrated containment radiation dose >10^6 rads (as determined by plant staff)
→Once declared, operators must continue using ADVERSE CONTAINMENT parameters unless integrated radiation dose is verified to be less than 10^6 rads.

Question 20

Post Accident Instrumentation Critical Safety Functions

Answer 20

→subcriticality (reactivity control)
→core cooling
→heat sink
→P - RCS integrity
→Z - containment integrity
→inventory (RCS)

Question 21

Tech Spec 3.3.3 PAM Instrumentation

Answer 21

→Modes 1-3
→PAM instruments must be operable