RRS malfunctions

what actions on CEDMCS will be taken on a failure of either Tcold, Tave, or Thot circuitry?

ensure CEDMCS is not in AS (place in standby)

In what way could a failure in RRS have an effect on COLSS?

if the failed instrument has failed within its normal range, it will affect COLSS

what happens if Tc or Th fails high with Tavg selected to avg

you will get an AWP, AMI, and PZR setpoint will go to max value

what happens if Tcold or Thot fails high on the selected channel (not in average)

AWP

CEA auto insertion (high rate)

PZR level will got to max setpoint

what happens if Tc or Th fails hi on the non selected channel

AWP only

what happens if Tc or Th fails low and Tavg is selected to average?

AMI

PZR level setpoint will lower,

letdown will increase

it Th fails high letdown will increase and also the CHP will stop

what happens if Tc or Th fails low on the selected channel (not in average)

PZR setpoint lowers (letdown increases and CHP stops

CEAS withdrawal demand (will move if not ARO)

depending on CEA position may cause CWP on DNBR, LPD or High Ppzr pre trips

what happens on Tc or Th failure hi regardless of selection

Prevents a SBCS QO block for group X valves on RX trip

Prevents runback demand on cutback

Max feed flow in RTO until NR reaches 51.9%

COLSS input is affected

RC loops temp Hi alarm and test panel lit

what happens if Tc or Th fails low regardless of selected channel

SBCS QO block for group X valves on a RX trip

Sends turbine runback demand to RPCS on cutback

no feed in RTO

COLSS input is affected

RRS test panel lit

Letdown will isolate on high temp

what happens on a TLI deviation?

TLI deviation greater than 5% will bring in AMI alarm and nothing else

what affect does TLI hi/lo failures have on SBCS master controller?

Rapid changes to SBCS master controller signal when in 1E control cause perturbations in DFCS which may result in a Rx trip

how do we determine the affected TLI instrument?

check the DVM. will read between 0-10V (8v=100% power)

what impact does movement of the TLI switch have on DFWCS

if DFWCS is in 1E movement of the switch can cause a Rx trip

what effect does a TLI hi failure cause on the plant if selected to average?

AMI

prevents SBCS QO permissive

No SBCS AMI permissive, no AMI until NI is less than 15%

SBCS sends continuous runback signal

what affect does a failed Hi TLI transmitter have when selected to the selected transmitter?

CEA auto withdrawal demand

Prevents SBCS QO permissive

no SBCS AMI until NI less than 15%

continuous runback signal on a cutback

no cutback signal sent on main turbine trip

what affect does a failed low TLI failure have when selected in average?

AWP

AMI

what happens on a TLI lo failure on the selected channel?

AWP

CEA high rate auto insertion demand

what happens on a TLI lo failure regardless of selected channel?

SBCS QO permissive generated for 10 seconds

TLI less than 15% generates SBCS AMI permissive

may cause RPCS TRBL annunciator

what happens on a TLI lo failure on a the unaffected channel

RRS test panel light only

what affect does a failed low NI failure have when selected to average?

AMI

what affect does a NI channel lo failure have when on selected channel?

AMI generated if SBCS failed to less than 15%

May cause CEA withdrawal

what happens on an NI channel failure Lo regardless of selected channel?

DWCS uses canned value for NI channels

DFWCS could go through valve swapover if the 2nd Ni fails low while one is in maintenance bypass (RX trip required if at high power)

what happens if Ni fails Hi when selected to average?

AMI

May see pulse rate to insert

what happens if NI fails HI when only selected to the failed detector?

May cause CEA insertion until rate of change power error goes away if CEDMCS is in AS mode

what happens on a NI channel Hi failure regardless of position?

Low power AMI can not be generated in SBCS

DFWCS uses canned NI value for ATUN

if at low power with one NI detector failed and in Maintenace a second NI failing high will cause swapover to occur and transfer to 3E control