Reactor Experiments Instructor: Prof. Kune Y. Suh T/A : Sang Hyuk Yoon Saturday, June 14, 2003 Composer : Team F

Contents Members and Malfunction Nuclear Power Plant System Drop of All Control Rod in CBA Turbine Trip FW Pump

Members of Team F Members of Team F Jeong, Won Chae Kim, Chan Soo Choi, Sang Gook Kim, Chan Soo Mun, Seung Hyeon Yoon, Ei Sung Lee, Yoon Jeong

Malfunction Choi, Sang Gook & Lee, Yoon Jeong A-1 Drop of All Control Rods in CBA Choi, Sang Gook & Lee, Yoon Jeong J-55 Turbind Trip Jeong, Won Chae & Yoon, Ei Sung L-67 FW Pump Trip Kim, Chan Soo & Mun Seung Hyeon

Power Plant System

Control Rod Choi, Sang gook Lee, Yoon Jeong

Control Rod Grid of the Control Rod GSSS

Control Rod control element drive mechanism CEA

Control Rod Methods to Control the Activity in Core Dilusion by Chemical and Volume Control System Boric acid is dissloved But the reaction is slow Using the Control Rods

Control Rod Function To control the reactivity of the core by quick putting and pulling out the control rod To solve the weak points of CVCS dilusion method

Control Rod Composition Totally 81 rods Shut Down group A,B Regulating Control group Part Strength Control group Control Element Drive Mechanism – Magnetic Forced Mechanism

Control Rod Composition Material of the toxic substance in rod - B4C Material of the cladding - Ni-Cr-Fe 652

Control Rod Control Rods Accidents 1. Ejection of the control rods Disorder of rod control equipment Mistake of operator Reactivity of the core increases Generation of Serious peak power Fuel damage, Trip

Control Rod Control Rod accident 2. Drop of all control rods in CBA Breaken equipment Interception of electricity Reactivity decreases Power generation decreases Pressure, Temperature, DNBR changes

Control Rod Net reactivity

Control Rod Average temperature of Primary loop

Control Rod Core coolant temperature

Control Rod Pressurizer pressure

Control Rod Steam generator Pressure

Control Rod DNBR

Control Rod Conclusion Drop of all control rods in CBA Output of whole core power decreases average temperature decreases reactivity increases(feedback effect) the reason of reactivity, DNBR movement According time goes, temperature and pressure decrease. The accident stops.

Turbine Jeong, Won Chae Yoon, Ei Sung

Turbine Function To convert the steam which is made in the steam generator to energy When the steam expands through the nozzle and blades of a turbine to a condenser, it rotates the rotor of the turbine blades, which links to the axis of the generator

Turbine Scene of Turbine Building inside

Turbine Scene of Turbine Building inside

Turbine Turbine

The system of the LP Turbine

The system of the HP Turbine

Turbine Causes of Turbine Trip Overload (Overspeed) Wearing the bearing Solenoid trip Low pressure of condenser The manual trip of turbine

Turbine Effects of the Turbine Trip Turbine Trip Steam dumped by ETS Pressure reduction The boiling point of the feed water is decreased The heat removed through the steam generator is decreased

Turbine Effects of the Turbine Trip The temperature of reactor coolant increase The reactivity of core decrease The sweeling of the water level in the Reactor DNB Melting down of core <<Serious Accident!!!>>

Turbine ETS (Emergecy Trip System) Interrupting the supply of steam and discharging it if turbine is tripped Functioning in mechanical or by the electrical signal from the detector

Turbine Anticipation Primary Loop Secondary Loop Temperature Increase Decrease Pressure

Temp. & Press. Incease in Steam Line Turbine Results Turbine Trip Turbine Load = 0 2nd Loop Flow Rate Dec. Feed Water Temp. Dec. Reaction for SAFE Heat Exchange Rate Dec. Water Level Dec. Pressure Inc. S/G Heat Transf. Rate Inc. Temp. & Press. Incease in Steam Line

Turbine Results Turbine Trip Turbine Load = 0

Turbine Results 2nd Loop Flow Rate Dec. Turbine Trip

Turbine Results Temp. of FW S/G Level S/G Prssure 2nd Loop Flow Rate Dec. Heat Exchange Rate Dec. Water Level Dec. Pressure Inc. S/G Feed Water Temp. Dec. Temp. of FW S/G Level S/G Prssure

Temp. & Press. Incease in Steam Line Steam Presssure from S/G Turbine Results Heat Exchange Rate Dec. Water Level Dec. Pressure Inc. S/G Temp. & Press. Incease in Steam Line Steam Presssure from S/G

Turbine Results Turbine Trip Cold Leg Temp. Inc. Reactivity Dec. 2nd Loop Flow Rate Dec. DNBR > 1.3 Heat Exchange Rate Dec. Water Level Dec. Pressure Inc. S/G Power Dec. SAFE Hot Leg Temp. Dec. Avg. Temp. Dec.

Turbine Results Cold Leg Temp. Reactivity Heat Exchange Rate Dec. Water Level Dec. Pressure Inc. S/G Cold Leg Temp. Inc. Reactivity Dec. Cold Leg Temp. Reactivity

Turbine Results Reactivity Dec. Power Dec. DNBR > 1.3 SAFE Relative Power DNBR

Turbine Results Avg. Temp. Dec. Hot Leg Temp. Dec. Power Dec. Avg. Temp. of Core

Feedwater Pump Kim, Chan Soo Mun, Seung Hyeon

Feedwater Pump Function Main feedwater system sends water to each steam generator(SG) Main feedwater pump circulates secondary water

Feedwater Pump

Feedwater Pump

Feedwater Pump

Feedwater Pump Scram of Indiviual Main Feedwater Pump 1. Lubricating Oil Low Pressure(0.62kg/cm2) 2. Turbine Overspeed(~4928RPM) 3. Condenser Low Vacuum Level(480.6mmHg) 4. Impellent Force Bearing Excess Abrasion 5. Low Inspiration Pressure(Lo-NPSH)(15.5kg/cm2)

Feedwater Pump Emegency Stop of All Main FW Pump 1. Safety Injection Signal 2. SG High Level 3. All condenser Pump Trip 4. Pump Release Header High Pressure

Feedwater Pump Identification of event and causes The loss of normal flow(LFW) event may be initiated by losing main feedwater pumps

Feedwater Pump Sequence of event and system Operation Decreasing water level and increasing pressure and temperature in the steam generator The RCS pressure and temperature rise. Reactor trip

Feedwater Pump Emergency Measure of the Accident Termination of main steam flow SG and Reactor Coolant System(RCS) pressurization Decrease in core heat rate

Feedwater Pump RCS becomes New Steady-state Condition Auxiliary feedwater Injection Cooldown by Operator

Feedwater Pump Analysis of Effects and Consequences Maximum RCS pressure and fuel integraty for the LFW is less than that for the loss of condenser vacuum event(LOCV) The initial Departure from nucleate boiling rate (DNBR) is the minimum DNBR The minimum DNBR remains above 1.30.

Feedwater Pump Conclusion The RCS pressure remains below 19.5MPa and the SG pressure remains below 9.6MPa Thus, ensuring fuel cladding and secondary system integraty [Assumtion] The only one pump would die.

Feedwater Pump S/G Generator #1

Feedwater Pump S/G Generator #2

Feedwater Pump S/G Generator #3

Feedwater Pump Average Temp. #1

Feedwater Pump Average Temp. #2

Feedwater Pump S/G Level Error Signal

Feedwater Pump DNBR