Power Operations

Question 1

When does the CR need to notify Chemistry during a Power Change? Why?

Answer 1

> 15% of RTP/Hour (9ZZ05)

NOTE: 9ZZ05 requires informing Chemistry during ANY power increase or decrease

TS 3.4.17, SR 3.4.17.2 - Verify I-131 (Minimize offsite dose, SGTR accident)

Question 2

What are the Required operator actions in response to Main Turbine Vibration?

Answer 2

Normal MT vibration is 5 Mils

Trip the Turbine IF:
1-Filtered vibration >10 mils, abrupt trend to 12 mils
2-Filtered >10 mils, slow to 12 mils after 15 mins

During downpower:
>2 mils - Stop downpower, reduce rate

Question 3

When should the Reactor be tripped during a Normal Plant power reduction with Planned Reactor shutdown?

Answer 3

1 - Sudden step increase in turbine vibrations of 2 mils

2 - Vibration has increased to 10 mils

Question 4

Monoblock rotors are susceptible to vibration based on what factors?

Answer 4

1 - Low Turbine Loading
2 - High Rates of Condenser vacuum change
3 - Main Condenser backpressure levels approaching 2”HgA
4 - Differential temperature across condenser section

Question 5

During Turbine startup, which shell is used for backpressure? What is maintained?

Answer 5

“C” shell

> 2” HgA and equal to or less than 4” HgA (as close to 4” as possible)

Max for “C” = <5” HgA

Question 6

MT can’t be operated for >1 hour when load is less than or equal to ___ with vacuum > than ____ HgA but less than or equal to ___

Answer 6

410 MW ; 4” ; 5”

Question 7

Turbine shall not be operated at less than ___ load with back pressure > ___

Answer 7

40% ; 5”

40OP-9MT02 also states that operation of MT in this condition may result in damage to MT

Question 8

How can we raise backpressure (less vacuum)?

Answer 8

Remove cooling tower fans and/or pumps from service

Question 9

Anytime a CW Pump operates, why do we have a sufficient number of Cooling Tower Fans in operation?

Answer 9

Ensures environmental license isn’t violated. Prevent spillage past concrete liner.

Question 10

Why is MT load reduced when FW Heaters are removed from service?

Answer 10

To prevent undue loading or overstressing of any turbine part.

Question 11

Why do we maintain correct DP across FW Econ Valves? And How?

Answer 11

Feed SGs during normal transients, Avoid excess DP causes valve oscillations, DP as low as possible to improve MW’s, at 100% maintain DP > 100#

BIAS the MFP speed controllers

Question 12

Per Appendix L of 40OP-9ZZ05, what is Monitored during CEA insertion or withdraw?

Answer 12

Reactor Power,
RCS Tavg,
CEA Group and subgroup deviations,
ASI

Question 13

Depressurizing the section of line between the FWPT discharge check valve and discharge valve prevents ___

Answer 13

Pressure Locking and potential Damage to discharge valves

Question 14

Why do we use the Generator capability curves (Appendix I, 40OP-9ZZ05)?

Answer 14

To maintain load, VARs and cooling within allowances to prevent generator overheat

Question 15

What are some of the factors that increase vibration susceptibility in Monoblock rotors?

Answer 15

LO Temps
Low Turbine Loading
High Rates of Power change
High rates of condenser vacuum change
Main condenser backpressure near 2" HgA
MSR Ops
Steam Drain Ops
Other thermal transients (steam to condenser)

Question 16

Operating all MSRs in same mode ensures Max Symmetrical Delta T on each LP turbine is maintained LESS than ___

Answer 16

50F

Question 17

PSCEA deviation will alarm a CWP when deviation is more than ___ inches

Answer 17

4.95”

Question 18

Max Generator cold gas temp at 75# is limited to ___

Generator terminal voltage limits are ___ to ___

Answer 18

48C

22.8 kV to 25.2 kV

Question 19

How long can we operate the Main Turbine if Exhaust Hood is between 200F and 225F?

Answer 19

15 minutes

Question 20

When power is < 70%, what is taken out of service? 60%? 50%?

Answer 20

70% - RPCB OOS “Auto Actuate OOS”
60% - Shutdown a MFWP
50% - Place SGN-HS-1189 in “Venturi” position

Question 21

When using Aux Spray during downpower, thermal shock occurs.

What must be determined for each cycle of main spray with < 4 RCP’s? And for Every cycle of Aux Spray?

Answer 21

Spray valve water differential temperature

Question 22

Power ascension max rate is ___ above 20%

This limit is changed to ___ above 40%

Answer 22

9. 5% per hour
10. 5% per hour initial after reload

NOTE: Monitor via JSCALOR (NKBDELT can be used)

Question 23

What is “Rapid Unloading”? And is it a Acceptable method?

Answer 23

1 to 3 minutes, by closing control valves quickly and tripping immediately thereafter

YES

Question 24

How do we maintain Operating ASI?

Answer 24

Boration and Dilution
CEA Movement (typically Groups 4 and 5) or PSCEA moves

Question 25

During power ascension with power >20%, ___ of full power ESI or as directed by Reactor Engineering

> 50%, ___ of full power ESI

Answer 25

+/- 0.05

+/- 0.01 (same with steady state)

Question 26

During power ascension or reduction, if ASI can’t be maintained ___ of full power ESI as directed by Reactor Engineering, and power is <70% (55% with COLSS OOS), then Group 4 CEA’s ___

Answer 26

+/- 0.05

May be inserted beyond the normal overlap limit

Question 27

What is NOT normally considered as an available method for ASI dampening?

Answer 27

CEA Withdrawal and Boration

Question 28

At EOC, Xenon oscillations are ___ and ASI oscillations become ___

Answer 28

More Extreme

Divergent

Question 29

When the bottom of the core has a HIGHER neutron flux than the top half of the core?

Answer 29

Negative Axial Offset exists

Axial Offset Anomaly - Caused likely by crud buildup on fuel assemblies in upper portion of reactor core

Question 30

If Power is shifted to the BOTTOM of the core, what happens?

Answer 30

Reduction in SDM and Increase in Local Peaking Factors

Question 31

The capability curve is limited by what?

Answer 31

Field Winding Temps
Armature Temps
Armature Core Temps

Question 32

If turbine vibration rapidly increases above setpoints, trip turbine and break vacuum at what setpoints?

Answer 32

<800 RPM - 8 mils

800-1400 RPM - 14 mils

1400-1800 RPM - 12 mils

NOTE: Breaking vacuum >1200 RPM may damage last stage buckets (LP)

Question 33

If downpowering due to loss of transmission lines, what is the time required for the evolution?

Answer 33

3 hours