LOIT 2020 exam prep > Exam 3 prep > Flashcards

Exam 3 prep Flashcards

SI and EDG (56 cards)

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1
Q

State the ECCS Design Criteria

A

HOTCC is pnemonic.

    • Peak Cladding Temp not to exceed 2200F
  • Max Cladding Oxidation such that no one place exceeds 17% times the total cladding thickness
  • Maximum Hydrogen Generation shall not exceed 1% of the amount generated if all cladding surrounding fuel reacted
  • Core geometry good for core cooling
  • Capable of long term cooling
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2
Q

State the SDC system design criteria.

A
  • Used to reduce RCS temperature post shutdown from 350F to 135F in 27½ hours @ a maximum of 75F/hr cooldown rate
  • SDC cannot be used at temperatures > 350F
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3
Q

State the CS Design criteria

A
  • Prevent containment from exceeding design temp and pressure 60# & 300F
  • Reduce containment pressure from peak value to ½ peak value in 24 hours
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4
Q

What are the setpoints for SIAS?

CSAS?

With regard to SI system, what occurs on these signals?

A
  • SIAS (1837# PZR Wide range, 3# Containment Pressure Narrow Range)
    • ALL SI Pumps start
    • HPSI and LPSI Injection Valves Open
  • CSAS (8.5# Wide range)
    • CS header valves only auto open on CSAS, Containment Spray pumps will start
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5
Q

Why do we have to have a minimum RWT volume?

A
  • Provides 20 min of FULL SAFETY Injection Flow with a 10% margin
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6
Q

Which HPSI pump would you use to fill the SITs?

What would happen to SIT level if the HPSI pump is secured before closing the throttle fill valve?

A

B train HPSI pump.

SIT will drain to the RWT.

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7
Q

What is the rated flow of the HPSI pumps?

What is the HPSI pump shutoff head?

What is the minimum indicated HPSI flow?

A
  • Rated flow is ~ 850 GPM @ 1230 psia (Usually divided into the 4 loops)
  • Shutoff head is 1880 psia (This is an important concept to understand)
  • Minimum indicated HPSI flow is 75GPM!!!!!!!!!
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8
Q

Each HPSI pump has a normally open discharge valve. Downstream of this there are 4 RCS loop isolations. How are these isolations repositioned for injection?

A. They are normally open valves and do not require repositioning.

B. They are MOVs that are opened by the operator once HPSI flow has been established.

C. They are MOVs that are opened on a SIAS signal to provide injection flow path.

D. They are interlocked with the HPSI recirc miniflow valves and will open once the miniflow is closed.

A

C. These valves are MOVs that are opened on a SIAS signal to provide injection flow without operator action.

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9
Q

How long can the HPSI pump run at minimum flow?

At what GPM flow can the HPSI pump run unlimited?

A
  • 1 hour @ 85 gpm (miniflow), Unlimited @ 225 gpm
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10
Q

State the rated flow and shutoff head for the LPSI pumps.

A
  • Rated flow ~4300 GPM @ 150psia
  • Shutoff head is 210 psia
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11
Q

How long can the LPSI pump run at 100 GPM?

At 2400 GPM?

what flow range should be minimized and why?

A

1 hour

Unlimited run time

2500-3500 gpm.

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12
Q

State the Rated flow and shutoff head for the CS pumps.

A
  • Rated flow ~ 3890 gpm @ 220 psia (> 4350 gpm post accident)
  • Shutoff head is 290 psia.
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13
Q

What flow rate requires the CS pump run time to be limited to 1 hour?

What flow rate allows unlimited run time?

what is the rumble region of the CS pumps?

A

150 gpm

2100 gpm

1800-2800 gpm

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14
Q

What must be done on an inadvertent CSAS signal(no SIAS) to gain control and stop the running SI pumps?

A
  • No override capability will be present the CS pump
    • The pump handswitch will be taken to the stop position causing the pump to stop and the breaker to be anti-pumped.
    • The pump cannot be restarted until the CSAS is cleared or the control power to the breaker is cycled.
    • If the breaker is anti-pumped and a SIAS subsequently occurs, the operator can start the pump by taking the handswitch to the start position twice. The first“start” places the pump in override and clears the anti-pump. The second starts the pump.
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15
Q

How are the SIT outlet valves ensured to be open at normal operating conditions?

A
  • Outlet valves: Auto open signal @ 410 psia RCS OR SIAS signal
  • On startup, the valves are opened and breakers are opened and locked.
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16
Q

State the TS limits for the SITs.

A
  • Tech Specs:
    • Modes 1, 2, or Mode 3 & 4 RCS pressure ≥ 1837 psia
      • 28-72% NR, 600-625 psia, 2300-4400 ppm Boron
    • Modes 3 or 4 w/ RCS pressure < 1837 psia
      • 4 SITs WR 39-83% or 3 SITs WR 60-83%
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17
Q

SDC should be removed from service above what temperature?

Why?

What temperature must be met to run SDC for more than 4 days?

A

> 260F

to preclude ECCS steam void formation and SDC gas binding.

<135F

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18
Q

What RCS pressure and temperature limits prevent CS pump alignment to supply SDC?

A
  • Containment Spray Pumps must not be aligned when:
    • RCS Temp > 200F and RCS Press >250 psia
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19
Q

What is the SDC HX max warmup rate?

A

19F/minute.

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20
Q

Why must SDC warmup line flow get subtracted from LPSI loop flow transmitter?

A

because this flow is not entering the RCS and must be removed from RCS total flow.

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21
Q

How is purification flow throttled when SDC is aligned the the CVCS system?

A
  • Purification flow is also not read by SDC flow transmitters
    • Controlled by throttling BACKPRESSURE control valves or LPSI injection valves
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22
Q

What pressure is the LTOP relief set to?

Where does it relieve to?

What is a good first clue that a relief has lifted?

A

467 psia

relieve to the containment sumps.

Containment sump temperatures will go up.

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23
Q

When can SDC suction valves be opened?

If this pressure is exceeded will the SDC suction valves auto close?

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A
  • SDC suction valves cannot be opened when RCS pressure >385 psia
  • NO
24
Q

How is the SDC low flow alarm configured and is there a risk of not being alerted to a loss of SDC flow?

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A

The alarm logic has breaker inputs and will not alarm if the breaker trips open. This can go unnoticed if a SEIS alarm is already in and result in a silent loss of SDC.

25
What must be true to operate the SIC-653 and SID-654 valves?
Supplied from an inverter and connected to the DC buses, the associated battery charger must have the battery connected to operate them.
26
WHat happens on a RAS signal?
* Containment sump to pump suction valves **auto open** * Safety injection pump miniflows **auto close** * Preserves containment inventory & prevents RWT contamination LPSI **auto trips** to ensure **NPSH for HPSI and CS pumps**
27
What operator action must be performed on a RAS and how long does the operator have to complete it?
* OPERATOR ACTION required to close RWT suction valves from CR (within 3 minutes)
28
What is the purpose of the TSP baskets?
* In containment to RAISE pH of Containment water **to maintain Iodine in solution** * Also minimizes stress corrosion cracking of stainless & reduces hydrogen generation from corrosion of containment metals
29
State the ratings of the DG.
* Rated for **5500 KW continuous output** * Can go up to **6050 KW output for 2 hours**
30
What will auto start the DG?
CLASs * CSAS(only starts in test mode) * LOP * AFAS * SIAS
31
When is the soonest the DG is capable of receiving load after start?
10 sec.
32
How long after the normal stop signal will the DG run? What is it doing during this time period?
5 minutes. testing the emergency run solenoids.
33
What will happen if the DG is tied to offsite power, then experiences a LOP or SIAS signal?
The DG output Breaker opens.
34
What will occur if the DG is in cooldown mode and receives an emergency start signal?
* It will run in emergency mode **but** pneumatic air pressure will bleed off as the test mode trips will not reset
35
What is the TS limits for DG FOST?
* ≥ 80% * **Provides 7 days of continuous op @ 100% rated output** * \<71% must declare DG inop
36
State the Fuel Oil Day tank minimum and how long the DG will operate at full load.
* Minimum level 2.75ft or 550gal * **more than 84 min. of op @ full load**
37
What is the fuel oil usage rate in GPM?
6.5 GPM at full load.
38
When will the DG overspeed trip actuate to shut down the DG? Will it work with a loss of control air? what must be done following a O/S trip?
* **Overspeed trip:** * ONLY trip that works on a loss of control air * **660 RPM auto trips** * Butterfly valve must be reset manually
39
What will cause the DG essential AHU to start?
* DG essential AHU is SLAVED to the Essential exhaust fan **(when it starts so does the AHU)**
40
When do the DG essential exh fan and DG essential AHU shutdown?
* Both Units will continue to run until the DG is shutdown AND room temp is \< 110F
41
State the TS limits for crankcase oil level
* T.S. for crankcase oil * 2.5” \< 1” then the DG is INOP
42
How many consecutive starts are the air receivers rated for at 250psig normal operating pressure? What are the TS air pressures and what actions are required at each level?
* Normally @ **250 psig** * That’s good for **5 consecutive starts for an INDIVIDUAL receiver** * T.S. for air receiver * \<230#, \<185# then the DG is INOP * **\< 230 psig (LCO 3.8.3) – 48 hrs to restore** * **\< 185 psig (LCO 3.8.3) – DG is inoperable**
43
Can the DG start with the turning gear engaged?
NO. A local alarm will indicate that the TG is engaged.
44
Why is NON FAIL SAFE air essential to safe DG operation? How would one stop the DG with a loss of NON FAIL SAFE air.
Non fail safe air is necessary to safely shutdown the DG by stopping the flow of fuel oil with the Fuel oil safety shutoff valve, pressurizes the trip air system. The DG must be manually stopped by closing the O/S butterfly valve or manually activating the fuel shutoff linkage.
45
What are the DG emergency mode trips?
GLO * Generator Differential * Low Engine Oil Pressure * **1 of 4 switches actuated in Test Run/2 of 4 in Emergency Run** * **Bypassed for 20 seconds on S/U and during shutdown \< 540 RPM** * **​**Overspeed \>660 rpm
46
Why is the DG placed in override after an auto start?
* **Placing DG in override after auto-start:** * Speed control is RE-ESTABLISHED * Voltage control is RE-ESTABLISHED * Speed and voltage control selectable between “ISOCH” and “DROOP” * **3 DG output breaker trips are re-established** * Overcurrent, Neutral Voltage, Negative Sequence * Disables DGSS hard start * Output breaker **WILL NOT TRIP** on subsequent **SIAS, AFAS.** * **WILL TRIP on LOP** * Get override light on B01
47
When in override: What will clear the override signal? What will occur if a LOP is generated? How is override cleared following a LOP? What is the concern with override following an inadvertent CSAS?
* Following AFAS, SIAS, CSAS or any DGSS Module driven start, override will clear when **reset actions are complete or if a LOP is received on the bus**. * If a LOP is generated, the **override will automatically be cleared** (load shed pulse 1 second). * After LOP, override will c**lear when the diesel is shutdown with the normal supply breaker closed.** * Override after an inadvertent CSAS will keep the override relay contacts open **preventing the subsequent start on a SIAS/AFAS**, but upon a LOP the override relays are reset allowing the DG to restart.
48
What will auto close the DG supply breaker following a start?
DOLL * **D**G rated speed and voltage * **O**pen Normal and Alt supply breakers * **L**OP * **L**ockouts not present.
49
What must be met to manually close the DG supply breaker from the CR?
LADS * **L**ockouts not present on bus * **A**lt supply breaker only one open. * **D**G @ rated speed and voltage * **S**ynch check.
50
What will occur if a test mode trip occurs following a DG manual start from the BOP ESFAS cabinet?
* With run signal locked in from cabinet: If a test trip is received **fuel turns off** DG slows down to **\<280 RPM** then starting air is applied. **Depletes starting air receivers**
51
What trips are active if the DG is manually started from the BOP ESFAS cabinet?
* DG starts but **all TEST MODE TRIPS are active** * With run signal locked in from cabinet: If a test trip is received **fuel turns off** DG slows down to **\<280 RPM** then starting air is applied. **Depletes starting air receivers**
52
State the control power to the DG and what will happen if power is lost while the DG is running?
* **Class Control Power - PKA-D21, PKB-D22** * DG trips, must manually open output breaker to prevent motorizing * Non Class control power - NKN-D42, NKN-D43 * DG trip if in test. * Prevent startup from control room. * Will Auto start in emergency run or Local Sim pushbuttons
53
What will occur if a loss of control air occurs while the DG is running?
* **Overspeed trip only auto trip** * DG output breaker will trip, DG will continue to run if no overspeed
54
What interlocks must be met for an auto start in any mode?
LOGME * Low LO pressure reset. * Overspeed trip reset * Generator differential reset * Mode select switch not in off * Emergency stop p/b reset.
55
Placing SDC in service above what temperature shortens LPSI pump seal life?
300F
56
What is the max procedural HUR/CDR when on SDC?
\<19F/min
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