Standard Operating Procedure Number 1101 6/1/1965
Heatup from Cold Iron Condition
GENERAL PLANT STARTUP PROCEDURE
HEATUP FROM COLD IRON CONDITION
The purpose of this procedure is to indicate the steps to be followed in taking the plant from the cold iron condition to the condition of decay head removal. The normal startup from the decay heat removal condition will proceed according to SOP 1101, Part II.
- 1. The reactor plant system are approximately as follows:
- a. Average temperature of the primary system is less than 200F.
- b. Primary System, including pressurizer, is filled solid with water. Primary system pressure is being maintained by the operation of one buffer seal booster pump. SL-121V is in hand control and open.
[The significance of being filled solid with water may refer to the SL-1 accident, where a reactor which was only partially full accidently went prompt critical, killed three people, and the water hammer from the partially full vessel bounced the 26,000 pound reactor vessel off the ceiling].
- c. Decay heat is being removed by one pair of letdown coolers. Letdown flow is approximately 10 gpm.
[A letdown cooler is a water to water heat exchanger, cooled by CW water, which cools the normally 508F primary system water to about 115F before it goes into the purification system. When the reactor is shut down, the chain reaction stops, as does most of the heat output. However the decay products are not stable, and continue to decay on their own, and emit heat. Immediately after a shutdown, the maximum decay heat will be nearly 12 megawatts (this is an 80 megawatt (thermal) reactor), it will drop off quickly, to the point that it can be handled by a single letdown cooler at 10 gpm.]
- d. The Purification System is operating with one ion exchanger and one filter in service.
[The purification system removes anything which is not water from the primary system water. The neutron flux in the core does not affect water, however anything dissolved in it can be activated by the neutrons, and become radioactive. This reduces that radiation hazard.]
- e. The letdown flow is returned to the Primary System by the operation of a buffer seal booster pump. The buffer seal charge pumps are shut off.
- f. One primary pump is operating at half speed.
There are a total of four primary pumps, only a single one is needed to keep the coolant going through the core. If the PS is cool enough, and completely depressurized, a portable pump can also be rigged to circulate the primary coolant, and all four primary pumps may be shut down. See POS RC]
- g. The control Rod Drive Hydraulic System is in operation at approximately 3000 psi. The control rod drives are de-energized (But T1) with all control rods fully inserted with a scram signal present on the safety system.
[When the reactor is shut down, it is left with the scram signal asserted.]
- h. Other plant system are in operation or standby status according to SOP 1101, Part II, Pages 2-5 Item 2(e) through Item 5.
- 1. Record the water levels in the following tanks:
- a. Buffer seal surge tank SL-T1
- b. Waste storage tanks PD-T1 PD-T2 PD-T3 PD-T4 PD-T5 PD-T6
- c. Effluent Condensing Tank PR-T1
- d. Charge pump gland leak-off collection tanks.
- 2. Vent the pressurizer through WL-1V for approximately five minutes.
- 3. Vent the reactor vessel head.
- 4. Energize the pressurizer heater banks 4 and 5. (Do not exceed pressurizer heat up rate of 70F/hr.)
NOTE: at approximately 300F the pressurizer level will start to drop. This will first be noted by an increase in SL-T1 level.
- 5. Approximately one hour before the pressurizer level starts to decrease, energize desurger heaters for two charge pumps (Refer to SOP 2130).
[The desurgers are an expansion tank immediately after the SL charge pumps. The heaters boil the water in the desurger, to maintain a compressible bubble of steam in the desurger, to even out the pressure pulses from the pistons of the SL charge pumps.]
- 6. Manually control SL-T1 level by opening PD-32V to drain to PD-T2 and PD-T3 when the high level alarm (55") is reached, and closing PD-32V when the low level alarm (40") is reached.
[As the system's temperature increases, the volume of the water increases, and that overflow has to go somewhere. Specificly, PD-T2 and PD-T3.]
- 7. As the pressurizer water level approaches 30 inches, secure heater banks 4 and 5. Control pressurizer pressure and level intermittently with heater banks 1 and 2. (Use band 3 if more heat is required.) Maintain pressurizer level at approximately 30".
[The normal level of water in the pressurizer is 27 inches, with the top of the tank full of steam. The pressure in the system is controlled by heating the water in the pressurizer with electric heaters. So the hottest part of the system is the pressurizer, and that is the only bubble of gas in the primary system.]
- 8. Establish telephone communication between the Port Stabilizer Room and Control Room.
NOTE: When the correct desurger temperature has been reached, a charge pump may be cut on, with the precaution that the buffer seal header pressure be watched closely to prevent excessive pressure.
[The SL charge pumps are designed such that the water in the buffer seals leaks into the reactor vessel. The highest pressure in the system is immediately after the SL charge pumps. When the system is starting up, the PS pressure is far lower, and the charge pumps can over-shoot.]
- 9. Open SL-60V (SL-9V bypass) approximately one turn.
- 10. Open SL-9V.
[Valve SL-9V is the pressure regulation valve for the SL water, and designed to operate at 1750 psig or so. Right now the PS pressure is 55 psig, so the bypass valve is opened to keep the pressure of the SL water closer to PS pressure.]
- 11. Start one charge pump at half speed. (Refer to SOP 2130).
- 12. Slowly close SL-9V (unless header pressure increases too much) and place in AUTO.
- 13. Position SL-60V (bypass around SL-9V) to place the "D" chamber (right hand.scale on controller) in mid-scale position with SL-9V in AUTO.
- 14. Check primary pump flush flow. Adjust flow to between 0.5 to 0.75 gpm. (Do not actuate flush flow on PS-P1).
[Primary pump flush flow (from SL) is on when the temperature of the PS is to be changed more than 30F, or if the pump is off for more than 30 minutes. I believe it is intended to make sure that if pump seals are going to seep, the flow will be into the PS. PS-P1 does not have flush flow.]
Note: As the primary pressure increases, it will be necessary to throttle SL-60V in order to maintain the SL-9V controller "D" chamber reading in mid-scale position.
- 15. Adjust pressurizer pressure to approximately 55 psig. (300F).
- 16. Place SL-121V in AUTO. Adjust set point to hold level at approximately 30".
- 17. Vent non-operating primary pumps and run all four pumps at 1/2 speed.
- 18. Complete Primary system heat-up according to SOP 1101, Part II.
Note: Prior to heating Primary System, provide drainage from steam generator through surface blow line to blow down evaporator, main steam stop and bulkhead stop drains to bilge.
Startup from Decay Heat Removal Condition
This procedure as written sets forth the steps for starting up the plant. It is written in a fashion such that, for the assumed plant conditions, the steps are to be followed sequentially. There may frequently occur variations from these assumed conditions as the time of ant particular startup; accordingly, departure from the sequence as written my be authorized by the First Assistant Engineer to meet the needs and requirements which may exist at the time.
- 1. It is assumed that the reactor plant systems are operating in such a manner so as to remove decay heat.
- 2. The reactor plant systems are situated as follows:
- a. Average temperature of Primary System is above 100F.
- b. Primary system pressure being maintained above 55 psig.
- c. Decay heat is being removed by one pair of letdown coolers. Letdown flow rate is adequate to remove decay heat, 60 gpm max.
- d. The purification system is operating with one or two ion exchangers and filters in service. Two filters and two demineralizers are required for letdown flows exceeding 30 gpm. Refer to SOP #2140.
[The primary coolant is deionized water, the purification system consists of ion exchange resin beds, just like one can find in a water softener or laser cooling system, which will extract any ions from the water, followed by several filters to prevent the resin beads from getting into the primary system. There are three sets of ion exchangers and filters, normally two are used and one is standby, but a single is sufficient to operate the reactor.]
- e. The buffer seal system is operating as follows to return the letdown flow to the primary system by the combined flow through the buffer seals and the primary makeup line. Refer to SOP #2130.
[Makeup water is water added to a boiler to make up for losses elsewhere in the system.]
- 1. Buffer seal charge pumps operating as required to maintain SL-9V in its operating range. At low primary system pressures the bypass valve around SL-9V must be cracked to maintain SL-9V in its operating range even with one charge pump at half speed.
- 2. One booster pump operating.
[The SL system has two centrifugal booster pumps, which feed three reciprocating charge pumps, which get the water to in excess of 1750 psig, and inject it into the buffer seals around the control rod pass through on the reactor pressure vessel such that the water will leak into the reactor vessel. Generally one booster pump, and two charge pumps are operated, with the third charge pump in reserve (switched off).]
- 3. Selector stations for valves SL-9V in AUTO. SL-121V being operated in AUTO so as to maintain pressurizer level.
- 4. Controls of desurgers of two charge pumps set for temperature corresponding to charge pump discharge pressure. Refer to SOP #2130.
- f. Two primary pumps in each loop operating at half speed.
- g. Containment cooling system in operation. Refer to SOP #7110.
[The interior of the containment vessel is cooled by the CC subsystem, an air to water heat exchanger cooled by CW water. It intends to get the containment vessel down to 115F.]
- h. Containment access is under control of the health physics group.
- i. The reactor compartment ventilation system is operating normally. Refer to SOP #7100.
[The containment vessel is within the reactor compartment. A slightly negative air pressure is maintained in the reactor compartment, so air leaks in, instead of out.]
- j. The instrument air system is operating. Refer to SOP #3100.
- k. The hydrogen addition system is secured. For operation as required, refer to SOP #3111.
- l. The intermediate cooling system is in operation. Refer to SOP #3101.
- m. The shield water tank is filled to a point above the low level alarm setting.
- n. The radiation monitoring system is activated. Refer to SOP #3152.
- o. The nuclear instrumentation system is activated. Refer to Appendix C.
- p. The sampling system is lined up and in normal operation. Refer to SOP #3140.
- q. The following systems are lined up and in a standby status:
- 1. The Relief System. Refer to SOP #3120.
- 2. The Emergency Cooling System. Refer to SOP #3102.
- 3. Equipment Drain and Waste System. Refer to SOP #3130.
- 4. Gaseous Waste System. Refer to SOP 3150.
- 5. Soluble Poison System. Refer to SOP 3103.
- r. Control rod drive system energized (Bus C, and F) with all control rods fully inserted and a scream signal is present on the safety system, i.e., scram reset not reset (SOP #2101).
- 3. The steam plant systems are situated as follows:
- 4. The following auxiliary systems are in operation:
- 5. The electrical plant equipment is as follows. Refer to corresponding section of SOP #6100.
- a. Auxiliary Diesel generators are supplying power to the main switchboard.
- b. One AC-DC MG set and one DC-AC MG set are in operation. Refer to SOP's #6140 and #6141.
[MG is Motor Generator. At this time, the cheapest most reliable way to convert AC to DC and vice versa is a motor mechanically driving a generator.]
- c. Battery systems are assumed fully charged and in standby status.
[The nuclear instrumentation has its own independent battery bank, which will run it for 3 days.]
- d. The emergency diesel generator is in standby status. Refer to SOP's #6120 and ^110.
- e. Power is being supplied through the normal distribution channels to the operating equipment.
- f. All ABT's set for AUTO
- 1. Complete reactor system valve check, using Appendixes A and E.
- a. Area 1: Engine Room and Pump Rooms.
- b. Area 2: Port Stabilizer Room and cross-flooding passageway.
- c. Area 3: Sampling Room.
- d. Area 4: Upper Reactor Void Space.
- e. Area 5: Secondary Shield Area.
- f. Area 6: Containment Vessel.
- 2. Complete console checkoff list using Appendix B.
- 3. Check that technicians have completed or are working on the following:
- Appendix C- Nuclear Instrumentation and Safety System Pre-Critical Checkout.
- Appendix D- Pre-Startup Check List for Control Rod Drive System.
- Appendix F - High Temperature Safety System Checkout.
- Appendix G - Primary System High and Low Pressure Safety System Checkout.
- Appendix H - Checkout and Calibration of Radiation Monitoring System.
- 4. If entrance to the Containment Vessel has been made, check that all tools, gear, etc., have been checked and accounted for.
- 5. During startup, perform those periodic tests in the Reactor Plant Operating Manual, Volume I, Section III, deemed necessary by the First Assistant Engineer.
- 6. Maintain primary pump flushing flow on pumps to be operated, with the exception of PS-P1, which does not require flush water. Refer to SOP #2134.
- 7. Establish buffer seal flow. Open rot seal return flow stop valve SL-8V. Refer to SOP #2130.
NOTE: Buffer seal flow must continue for four (4) hours prior to moving any control rod when PS temperature is above 200F.
[Buffer seal water cools the O rings around the control rods. They are made of buna-N, and will be damaged above about 300F.]
- 8. Primary Pump, Primary Gate Interlock Check:
[This tests that the primary pumps will automaticly shut off if the valves in the primary system are closed. The startup checks exercise most if not all of the safety interlocks.]
- 9. Check PS-SL Differential Pressure Interlock.
- a. Place SL-9V controller in hand.
- b. Place one charge pump on half speed.
- c. Place non-operating charge pumps in the OFF position.
- d. Slowly reduce buffer seal charge pump discharge pressure.
- e. Check that SL-8V closes when the buffer seal pressure drops to within approximately 5 psig of the reactor pressure.
- f. Return system to normal.
- 10. Before starting heatup, check that the Boiler Circulation System is secured and ascertain that inter-connecting flexible couplings are disconnected.
[The letdown coolers may be configured to remove decay heat using a portable pump connected to fittings in the containment vessel, instead of the primary pumps. The pump and hoses must be disconnected before significant pressure is achieved. See POS RC ]
PRIMARY SYSTEM WARMUP:
NOTE: Temperature increase in the Primary System is limited to 35F per hour, and in the Pressurizer it is limited to 70 F per hour.
[If the system is warmed up too quickly, the metal on the inside of the various pressure vessels will expand more than the metal on the outside of the vessel and cause thermal stress. At 35F per hour, there is enough time for the pressure vessel walls to warm up through their entire thickness.]
- 1. Establish the pressure at 110 to 125 psig as follows:
- a. Position all five heater bank selector switches to ON. Check that indicating lights illuminate (1 and 2 GREEN; 3, 4, and 5 AMBER)
- b. Rotate slidewire on the console-select pressurizer level transmitter to less than 6". Check that the pressurizer heaters de-energize.
- c. Return pressurizer heaters to service. Select other pressurizer level transmitter, and repeat step (b).
- d. Return all pressurizer heaters to service.
- e. When primary system pressure reaches 110 to 125 psig, use spray flow (PE-1V to 3V in HAND) as required to maintain the pressure in this range. Surge line temperature cycles with a primary system to pressurizer temperature differential above 225F shall be avoided. Pressurizer level fluctuations will probably occur if either SL-121V or SL-9V are operated in manual, or if insufficient charge pump capacity is available. Level decrease is noted first by an increase in the surge line temperature.
- 2. If required, reduce main switchboard electrical load to allow for bringing two or three primary pumps on the line at full speed.
- 3. Start two or three primary pumps and bring to high speed. Follow SOP #2120.
- 4. Adjust letdown flow at the minimum required to maintain pressurizer level. Any additional letdown will impede plant warmup.
- 5. If required, and when boiler pressure will allow it, blow down boilers to operating level.
[Blowdown is intentionally venting steam or water from a boiler, to remove contaminants.]
- 6. Complete the CRDL checklist up to Step 40. See Appendix D.
- 7. Buffer seal surge tank drain valve PD-32V shall be manually controlled to maintain level in the SL surge tank.
- 8. Check that the Equipment Drain and Waste System is valved so that the expansion water will be directed to waste storage tanks PD-T2 and PD-T3 by valve PD-124V. Refer to SOP #3131.
- 9. When the primary system temperature reaches 180 - 200F, increase the pressurizer pressure in accordance with PS-09, PE-15, Figure II, Plant Operating Standards.
- 10. Buffer seal inlet pressure will increase as the Pressurizer pressure increases. The control dial setpoints of the operating desurgers must be reset during the pressure rise. Follow SOP #2130. Eventual setting will be 1830 psig.
[Nominal PS pressure is 1750 psig, 1830 psig keeps SL pressure above PS pressure.]
- 11. at 500 psig pressurizer pressure, vent the pressurizer through WL-1V. Letdown will have to be increased during this period to obtain the required vent flow. Vent for five minutes, or until the pressurizer temperature corresponds within 10F to saturation temperature for the pressure.
- 12. When Primary System temperature reaches 225F: Vent air from the steam drums and steam outlet lines by intermittently opening the manual bypass valves on the quick closing steam stop valves.
[The steam generators consist of a cylindrical tank mounted above a second U shaped tank. The two tanks are connected together with several vertical pipes (called downcomers). The U shaped tank has many U shaped stainless steel tubes carrying PS coolant. The water surrounding the tubes will boil, and steam will flow up the downcomers. The top tank is called the steam drum. See Steam Drum.]
- 13. When the primary system temperature reaches 240F reduce pumps to four at half speed.
- 14. Check the low pressure scram and alarms.
- a. Complete Appendix G.
- b. Increase pressurizer pressure high enough to reset all low pressure primary and pressurizer alarms. Record reset points.
- c. Drop the pressure low enough to trip both alarms and scram. Record the actuating pressure and compare scram setpoint with values in Appendix G. Do not spray with greater than 225F delta-T.
- 15. Resume pressurizing to 1735 psig.
- 16. Check that the operating desurger heater monitoring dials are set to the temperature corresponding to 1840 psig system pressure. (420F upper heater and 590F lower heater). Refer to SOP #2130.
- 17. Check that CW-39V bypass, CW-140V, is open. Use CW-39V to control purification temperature at 110F. maximum. In order to prevent flashing of CW water in PP coolers, outlet temperature will have to be less than 110F.
- 18. Complete "RMS Operational Checkout" Appendix H.
- 19. Complete "Nuclear Instrumentation Calibration Check" Appendix C.
- 20. Complete "Checkout of Safety System High Temperature Circuit," Appendix F.
- 21. Complete "CRDS Pre-startup check", Appendix D.
- 22. Check out remainder of non-nuclear scram circuits. These may be used to scram individual rods as required in Appendix D or they may initiate signal only as far as the alarm-scram panel No. 2.
- a. Rod drive hydraulic power supply.
- b. Rod test interlock.
- c. Check one scram-all scram (refer to Appendix D, page 7).
- d. Rod drive undervoltage.
- e. Low primary system flow.
- f. Pump monitor.
- (1) Requires one pump at half or full speed with Start-Run switch in START.
- (2) Requires one pump at full speed with Start-Run switch in RUN.
- (3) Check that Emergency Cooling System and Emergency Diesel Generator starts automatically following actuation of the pump monitor.
NOTE: IF there is an interruption in safety circuit continuity following any of the preceding checks, a complete operational recheck of the affected parts of the circuit shall be performed prior to startup.
- 23. Make final containment entry to check all equipment for leakage, including control rod drive structure for indications of oil leakage and boiler level instrumentation valves for steam and water leakage.
- 24. Secure the containment vessel airlock. Perform air test of air lock.
- 25. Perform CV inert procedure SOP #3163 concurrent with plant heatup, allowing sufficient time of complete inerting operation prior to reaching 400F primary system temperature and before withdrawing more than one control rod (except for App. D rod testing).
26. Clear and secure the secondary shield area.
- 27. Checkout of Rod Bottom Interlock:
- a. Stop starboard loop primary pumps and close reactor inlet valve in starboard loop.
- b. Withdraw the A Group rods 3 inches.
- c. Attempt to start either pump in the starboard loop.
- d. Insert the A Group rods to their lower limit.
- e. Restart starboard loop pumps at half speed.
- f. Repeat steps (a) through (e) for the port loop.
- 28. Check BF3 Interlock.
- 29. Have the chemist check to see that primary system water quality is as specified before bringing the reactor critical.
- 1. A final check of the nuclear instrumentation should be made as follows:
- a. Insure that power is on at the nuclear cabinets, that signal operator panels are reset, and that scram-alarm panel is clear.
- b. Start-Run switch is in START.
- c. Channels 1 and 2 count rate on-off switch is ON.
- d. Auto-Manual switch is in MANUAL.
- e. Observe count-rate meters in Channels 1,2,3 and 4. Normal rod withdrawal is allowed only if a counting rate greater than 1.5 cps exists in 1, 2, 3, or 4. If a count rate less than 1.5 cps exists refer to SOP #1152.
- 2. The following steam plant operation shall be performed while continuing plant heat-up:
- a. Start lube oil system. Refer to SOP #5130. The following trips shall be demonstrated:
- (1) Low Oil Pressure
- (2) H.P. Overspeed
- (3) L.P. Overspeed
- b. Start main engine turning, using shaft turning gear, Refer to SOP's #8153 and #8151.
- c. Raise vacuum on main engine.
[Vacuum refers to the main condenser. Since the condenser is going to condense all of the steam, and there is no air in the system, the pressure in the condenser will be below atmospheric pressure. The condensed steam will then be feed water, and is pumped back into the steam generator by the feed water pumps. Losses will be made up for by adding makeup water.]
- 1. Proceed with normal reactor startup by use of SOP #1104. For Sourceless Startup refer to SOP #1152.
- 2. Containment vessel inerting procedure must be completed before the primary system temperature exceeds 400F or if more than one control rod is withdrawn (except for App. D testing).
- 3. Continue plant heatup by use of reactor power. Adjust reactor power so that 35F/hr average limitation is not exceeded.
- 4. Maintain a check on steam generator drum levels. Add or blowdown water as required. (SOP #5100)
- 5. Within the following limitations and precautions, secondary steam loads may be added during the heatup.
- a. Reactor power must be greater than 1% F.P.
- b. Start-Run switch must remain in the "START" position until primary system temperature exceeds 490F.
- c. The reactor operator must be informed whenever the steam plant load is to be changed.
- d. A chemistry check of the DFT indicates satisfactory conditions for use in the main steam generators.
- e. The steam plant operator must exercise care whenever adding cold feedwater to the steam generators to prevent a sudden increase in reactor power.
- 6. Observing above limitations, a suggested sequence of adding secondary steam loads is as follows. Deviations from this sequence may be dictated by plant conditions at the time of startup.
- a. Warmup high pressure steam piping.
- b. Line up 150 lb. reducing station. Start L.P. steam generator and secure auxiliary boiler. (SOP #5111)
- c. Line up 26 lb. reducing station to head DFT.
- d. Line up 85 lb. reducing station.
- e. Place blowdown evaporator in service. (SOP #5100)
- f. Obtain and analyze boiler water samples.
- g. Line up and start auxiliary circulating system for either T.G. #1 or T.G. #2. (SOP #4142)
[T.G. is turbo generator, "turbo" just means turbine driven. The two turbo generators are rated at 1500 KW each, bus voltage is 450VAC three phase.]
- h. Line up and start auxiliary condensate system for either T.G. #1 or T.G. #2. (SOP #4141)
- i. Line up and start auxiliary air ejector for either T.G. #1 or T.G. #2. (SOP #4143)
- j. Place Quantichem into service (SOP #5142).
[Quantichem is a continuous water quality monitoring device. It checks for contaminants in the feed water, and monitors ph.]
- k. Check that DFT temperature is at least 212F.
- l. Start either T.G.#1 or #2. (SOP #4140)
- m. Start other T.G. in the same fashion, and secure auxiliary diesel generator.
- n. Start main feed pump and secure port feed pump, if desired. (SOP #4131)
- o. Place low pressure evaporator plant in service. (SOP #8170)
- 7. When the primary average temperature reaches 508F and the above equipment is in service, the plant is in normal "in port" operation.
- 8. Approximately one hour before the departure of the ship, switch the Start-Run switch from "Start" to "Run."
NOTE: Electrical load, along with 20% F.P. trip setting, will probably require to PS pumps operating at full speed rather than all four until Start-Run switch is changed to RUN.
- 9. Warm up main engine after informing reactor operator. (SOP #4101).
My text copyright 2020 Tommy Johnson, all rights reserved. I believe the Savannah documentation is property of
MARAD or the US government.