RCP emergencies

Question 1

What is the potential damage associated with high motor or bearing temperatures on the RCPs?

Answer 1

Insulation breakdown causing internal faults which could lead to a RCP trip.

Bearing temperature results in failure and potential seizure.

Question 2

What actions should be taken if an upper thrust bearing temperature is 245F or more?

Answer 2

If >245F or more or > 520 amps, then trip the Rx, and turn off the affected RCP.

Consider starting the Lift Oil Pump to slow the rate of temperature rise.

Question 3

What will be the temperature response when Seal Inj is secured to an RCP?

Answer 3

Normal RCP HPSC inlet temp is ~100-110F

Securing Seal Inj will rise HPSC inlet temp to approx 200-220F will all other seal temperatures being normal.

Question 4

State the required TCAs associated with a loss of NC to RCPs.

Answer 4

From the time of the loss of NC, power must be reduced or cooling water isolated and the RCP shutdown within 30 minutes. This is to protect the motor and bearings from a loss of cooling to the lubricating oil, or motor assy bearing seizure may occur.

Question 5

State when seal damage can be experienced to an RCP in standby following a loss of Seal Inj and NC.

Answer 5

Seal damage could occur within 20 minutes. Should this occur and seal failure occur, the maximum RCS leakage from all three seals failed is ~17gpm per pump. If all three seals failed on all 4 RCPs that is a leak rate of ~68gpm and within the capacity of 2 CHPs.

Question 6

What is the normal seal pressures and approximate seal breakdown across the package?

Answer 6

Seal 1 inlet: 2230-2250psia

Seal 2 inlet: 1250-1300psia

Seal 2 outlet: 250-320psia

Question 7

What parameters would indicate an failed seal?

Answer 7

On a failed seal, that seal’s bleedoff flow would increase. Additionally, the d/p across that seal would go down and the remaining unaffected seals d/p would rise to account for the total pressure breakdown. Should Seal 2 outlet press exceed > 1700psia, then a Rx shutdown and secure the affected pump.

Question 8

Based on controlled bleedoff, determine if the RCP can continue to operate.

Answer 8

If CBO is >= 9.5 or <0.5, then:

Trip the Rx

Stop the affected RCPs

Isolate CBO.

Continue in SPTAs

Question 9

What seal conditions woudl neccessitate a reactor shutdown?

Answer 9

two failed seals on any RCP

Seal 2 outlet press > 1700psia

Seal 1 or seal 2 press drop is > 1700psid or more(indicates 2 failed seals.

CRS determines.