PZR/PRT Flashcards
State the functions on the pressurizer
H- Holds and maintains coolant pressure during stead state operation, preventing bulk boiling enabling coolant to remove core heat
E- Establishes normal operating pressure during startup
L- Limits the pressure changes caused by thermal expansion and contraction during plant transients to acceptable values
P- Prevents reactor coolant system from exceeding the safety limit value 2735#
State the transients that the Pressurizer is designed to accommodate without causing a reactor trip
power increase or decrease of 5% per min with auto rod control
Instantaneous transients of +- 10% with auto rod control
Step load reduction of 50% of full power with auto rod control and steam dump operation.
State Normal Temp/Press for PZR
650F
2235#
State design pressure/ Safety valve set pressure
2485
State PZR HU/CDR
HU: 100F/HR
CD: 200F/HR
State Max spray water delta T
320F
State RCS connections for PZR surge and spray lines
Surge: Loops 3 Hot Leg
Spray lines: loops 1 and 3: PCV-455B/ PCV-455A
Aux spray from CS-V-185 (charging line)
State the functions of PZR spray bypass flow
Maintains the spray lines warm to prevent thermal stresses to spray lines and nozzle
Equalize boron concentration to prevent reactivity addition during outsurge
State how the PZR responds on an insurge
Steam Demand goes down
Less heat removed -> Cold leg temp increases
Tave increases -> RCS expands into PZR compressing bubble
PZR pressure rises above saturation and bubble condenses which lowers pressure
Large insurge may cause spray actuation
State how the PZR responds on an outsurge
Steam demand increases
More heat removed -> Cold leg temp decreases
Tave decreases -> RCS contracts and flows from PZR
PZR level decreases and bubble expands
Pressure drop causes liquid to flash to steam which increases pressure
Large outsurge may energize heaters
State methods used to limit temperature in the PRT
Flow enters the PRT through the sparger which is under water
PRT has a pump and HX which cools PRT contents, auto on <120F
Discuss N2 blanket in PRT
Prevents introduction of air to minimize corrosion of the tank
Prevents build up of explosive H2
Discuss PRT auto recirculation
PRT pump auto starts at 120F
Pump switch much be in auto and transfer switch must be in recirc
State T.S. 3.4.2.1 (RCS Safety Valves - Shutdown) LCO and Actions
A minimum of 1 PZR Code safety valve shall be OPERABLE with a lift setting of 2485# +- 3%
MODE: 4 and 5
With no PZR Code safety valve OPERABLE, immediately suspend all operations involving positive reactivity changes and place an OPERABLE RHR loop into operation in the shutdown cooling mode
State PRT rupture disk setting
91#
State T.S. 3.4.2.2 (RCS Safety Valves - Operating) LCO and Actions
All PZR Code safety valves shall be OPERABLE with a lift setting of 2485# +- 3%
MODES: 1,2, and 3
With one PZR Code safety Valve inoperable, either restore the inoperable valve to OPERABLE status within 15 minutes or be in at least HOT STANDBY within 6 hrs and in at least HOT SHUTDOWN within the following 6 hrs
State T.S. 3.4.3 (Pressurizer) LCO and Action
The PZR shall be OPERABLE with a water volume of less than or equal to 92% and at least two groups of PZR heaters each having a capacity of at least 150kW and capable of being powered from an emergency power supply
MODES: 1,2, and 3
b. With the PZR otherwise inoperable, fully insert all rods, place the Control Rod Drive System in a condition incapable of rod withdrawal, and be in at least HOT STANDBY within 6 Hrs and in HOT SHUTDOWN within the following 6 Hrs
State T.S. 3.4.4 (Relief Valves) LCO and Action
Both power-operated relief valves (PORVs) and their associated block valves shall be OPERABLE
MODE: 1,2 and 3
With one or both PORVs inoperable within 1 hr either restore the PORVs to OPERABLE status or close the associated block valves(s)
