Student Operating Procedure Millstone Station Shutdown and Cooldown of SEE-THRU Nuclear Power Plant for Student Performance Approval Date: 10/4/2007 Effective Date: 10/4/2007
TABLE OF CONTENTS 1. PURPOSE...3 1.1 Objective...3 1.2 Discussion...3 1.3 Applicability...3 2. PREREQUISITES...4 2.1 General...4 3. PRECAUTIONS...5 3.1 Safety Precautions...5 3.2 General Precautions...5 3.3 Operating Limits...5 4. INSTRUCTIONS...6 4.1 Securing the Secondary Plant...6 4.2 Reactor Shutdown...7 4.3 Plant Cooldown and System Shutdown...10 2 of 11
1. PURPOSE 1.1 Objective This procedure provides instructions for the shutdown and cooldown of the SEE-THRU Nuclear Power Plant. Students under the instruction of a qualified instructor may use this procedure. 1.2 Discussion This procedure provides instructions to allow students to perform a shutdown and cooldown of the SEE-THRU Nuclear Power Plant. 1.3 Applicability This procedure is applicable for student operation of the SEE-THRU Nuclear Power Plant. 3 of 11
2. PREREQUISITES 2.1 General 2.1.1 The instructor has conducted a pre-job brief with all students for this activity. 2.1.2 Students have reviewed and understand the safety precautions, general precautions and SEE-THRU Nuclear Power Plant operating limits. 2.1.3 Students have reviewed the SEE-THRU Nuclear Power Plant layout and are cognizant of the locations of the major plant components, operating controls, local valves, pumps and instrumentation indicators. 4 of 11
3. PRECAUTIONS 3.1 Safety Precautions 3.1.1 Always operate the SEE-THRU Nuclear Power Plant with the containment plexiglass (cylinder and dome) and component plexiglass covers in place to prevent scalding from hot water or steam in the event of a primary or secondary plant leak or rupture. The containment and component covers must also be in place to prevent serious lacerations or other injuries from broken/flying glass should a glass component break. 3.2 General Precautions 3.2.1 When selecting RUN for any pump, select STOP immediately if there is an abnormal noise or if an abnormal noise develops during operation. 3.2.2 Do NOT run any pump at its shutoff head for an extended period of time. 3.2.3 Do NOT allow the condenser to pump empty because this will cause air binding of Condensate Pump - P4 and/or Feed Pump - P3. 3.2.4 When the reactor coolant system is solid (no steam bubble in pressurizer), a small change in temperature will result in a significant change in system pressure. 3.2.5 When operating Feedwater Regulating Valves FRV-FW1 and FRV-FW2, Reactor Vessel Vent Valve RC-15, and Pressurizer PORV Isolation Valve RC-22 in the closed direction, do NOT run them hard into their seat in order to prevent damage to the valves. 3.3 Operating Limits 3.3.1 Ensure that the following operating limits are not exceeded: a. Reactor coolant system pressure is maintained less than 23 psig b. Reactor temperature is maintained less than 275 F c. Pressurizer temperature is maintained less than 275 F d. Condenser water level is maintained greater than 1/3 full e. Containment temperature is maintained less than 180 F 5 of 11
4. INSTRUCTIONS 4.1 Securing the Secondary Plant 4.1.1 If feedwater heater is in operation, perform the following steps to shutdown feedwater heater: a. CLOSE valve Feedwater Supply MS5. b. CLOSE manual isolation valve MS-9. c. CLOSE valve Feedwater Heater Drain MS6. 4.1.2 If vacuum pump is in operation, perform the following steps to shutdown vacuum pump: a. STOP Vacuum Pump P5. b. OPEN manual isolation valve MS-13. c. CLOSE manual isolation valve MS-12. - End of Section 4.1-6 of 11
4.2 Reactor Shutdown 4.2.1 LOWER Reactor Power to 0 amperes. 4.2.2 When Turbine Speed lowers to 500 RPM, perform the following steps to shutdown the secondary plant: a. TURN the Turbine Generator Exciter control knob fully counterclockwise to its minimum position. b. SWITCH the Turbine Generator Exciter switch to OFF. c. OPEN valve Bypass-MS3 (Steam Dump to the Condenser). d. CLOSE valve TSV-MS4 (Steam to the Main Turbine). e. VERIFY Turbine Trip annunciator light is lit. 4.2.3 PRESS the Reactor Trip push button. 4.2.4 VERIFY Reactor Trip button red light is lit AND Reactor Trip alarm is lit. 7 of 11
s CAUTION s 1. When operating the Feedwater Regulating Valves FRV-FW1 and FRV- FW2, in the closed direction, be careful not to run them hard into the seat to prevent damaging the valves. 2. Proper water levels (approximately ½ to1 inch above the tube bundles) must be maintained while boiling is occurring in the secondary side of the steam generators 3. Do NOT allow the condenser to pump empty because this will cause air binding of Condensate Pump - P4 and/or Feed Pump - P3. 4.2.5 When boiling stops in the steam generator, perform the following: a. CLOSE Feedwater Regulating Valves FRV-FW1 for A S/G and FRV- FW2 for B S/G. b. STOP Feed Pump P3. c. STOP Condensate Pump P4. s CAUTION s Steps 4.2.6 through 4.2.7 must be performed quickly to prevent an automatic actuation of the Safety Injection System. 4.2.6 Perform the following to de-energize the pressurizer heaters: a. CLOSE valve Pressurizer Spray RC4 AND ALLOW pressurizer pressure to stabilize between 19 and 21 psig. b. PRESS F1 then F5 on the Master Display/Controller to display Pressurizer Control. c. PRESS F7 switch from Automatic to Manual pressure control mode. d. VERIFY Pressurizer Control is in MANUAL. e. PRESS F6 On the Master Display/Controller f. ENTER 0% (TYPE in 0 and depress the enter key) g. VERIFY 0% output is displayed. h. PLACE the Pressurizer Heater switch in the OFF position. i. PRESS F1 then F2 on the Master Display/Controller to display pressurizer water and reactor temperatures. 8 of 11
s CAUTION s When the reactor coolant system is solid (no steam bubble in pressurizer), a small change in temperature will result in a significant change in system pressure. 4.2.7 Perform the following steps to fill the reactor coolant system to a water solid condition: a. CLOSE manual valve RC-22 b. OPEN valve RC-5, Pressurizer PORV c. START Safety Inj Pump - P1. d. PLACE the Injection SI1 key switch to Bypass (key in horizontal position - ¼ turn clockwise). e. OPEN valve Injection SI1. NOTE Pressurizer pressure may lower to 8 to 10 psig and then stabilize between 10 and 15 psig when the reactor coolant system is water solid and valve RC-22 is closed. f. SLOWLY OPEN manual valve RC-22 and allow the pressurizer to gradually fill. - End of Section 4.2-9 of 11
4.3 Plant Cooldown and System Shutdown NOTE 1. Operation of valve RC-22 will require constant attention during the plant cooldown. 2. A slower cooldown rate will cause less stress on the plant components. 3. Opening manual valve RC-22 will provide a flowpath from the pressurizer to the quench tank/rwst. 4.3.1 THROTTLE manual valve RC-22 to MAINTAIN Pressurizer Pressure between 10 to 13 psig. 4.3.2 When reactor temperature reaches 150 F, perform the following: a. THROTTLE manual valve RC-22 to MAINTAIN Pressurizer Pressure at 5 psig. b. CLOSE valve Injection SI1. c. MONITOR Passive Accumulator Pressure gauge for lowering pressure. d. When Passive Accumulator pressure lowers to 3 psig, OPEN valve Injection SI1. e. THROTTLE manual valve RC-22 to maintain Pressurizer Pressure between 10 to 13 psig for the remainder of the cooldown. 4.3.3 WHEN pressurizer and reactor water temperatures are < 120 F, PERFORM the following: a. CLOSE valves Pressurizer PORV RC-5 and Injection SI1 simultaneously. b. FULLY OPEN manual valve RC-22 AND VERIFY Pressurizer Pressure remains stable. 10 of 11
4.3.4 Perform the following steps to stop reactor coolant system flow: a. STOP Reactor Coolant Pump P7. b. STOP Reactor Coolant Pump P6. c. STOP Safety Inj Pump - P1. d. CLOSE valve Flood SI2. 4.3.5 ADJUST water levels by using the associated fill and drain valves and pumps to achieve the following: Reactor - SOLID. Pressurizer - SOLID. Passive Accumulator - 2/3 FULL. Passive Accumulator - 0 psig. Condenser coils - COVERED. Steam Generator water levels - above FEED RING. 4.3.6 VERIFY the status of the following components: Pressurizer SURGE-RC3 = OPEN. Main Steam Isolation Valves MSIV-MS1 and MSIV-MS2 = OPEN. BYPASS-MS3 (Steam Dump to the Condenser) = OPEN. ALL OTHER main control board valves = CLOSE (green status lights). 4.3.7 STOP the Containment Air Recirculation Cooling (CARC) fan by turning the CARC control switch to the OFF position. 4.3.8 CLOSE valve Circ Water Reg CW1. 4.3.9 CLOSE the CIRC WATER THROTTLE VALVE to condenser. 4.3.10 TRIP the sump pump GFCI. 4.3.11 CLOSE the CIRCULATING WATER supply line VALVE on wall. 4.3.12 DEPRESS the Reactor, PZR, S/G, RWST, T/G, and COND push buttons to de-energize the display lighting. 4.3.13 TURN OFF main power on console. 4.3.14 TURN OFF main power wall switches. - End of Section 4.3-11 of 11