ML20212C795
| ML20212C795 | |
| Person / Time | |
|---|---|
| Site: | University of California-Davis |
| Issue date: | 10/07/1997 |
| From: | Richards W AIR FORCE, DEPT. OF |
| To: | Eresian W NRC |
| Shared Package | |
| ML20212C798 | List: |
| References | |
| NUDOCS 9710300187 | |
| Download: ML20212C795 (11) | |
Text
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DEPARTMENT OF THE AIR FORCE HEADQUARTERS SACRAW(NTO Alm LO0lsflCS CtNT(R(AFMC)
McCLtLLAN AIR FORCE BASE. CALIFORNIA 7 Oct 97 Shi-ALC/TI-l 5335 Price Avenue hicClellan AFB CA 95652-2504 hir. Warren Eresian U.S. Nuclear Regulatory Commission Mail Stop O-11-B 20 10555 Rockville Pike Rockville MD 20852-2738 Ref: Docket No. 50-607 Dear hir. Eresian The attachments are in response to your 22 Sep 97 letter,
Subject:
Request for Additional Information by the Oflice of Nuclear Reactor Regulation Related to the Application for an Operating License for the hicClellan AFB TRIGA Reactor, Docket No. 50 607.
Questions concerning these responses should be directed to Dr. Wade J. Richards, (916) 643-1024.
Sincerely cel.L.
WADE J. RihARD , Ph.D.
WS Chief, Nuclear Licensing and Operations 2 Attachments:
/
- 1. Questions and Responses 2, Appendix A ,
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l QUESTION It !
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Provide a complete physical description of the secondary cooling system and its mode of '
operation. This should include capacity, flow rate, delta T during normal operation, blow.
down volume and frequency, chemical treatment, evaporation rate, and makeup water source and volume.
1.0 PHYSICAL DESCRIPTION i
The secondary cooling system removes heat from the primary cooling system by circulating water through a plate type heat exchanger that transfers heat from the primary coolant to the secondary coolant. A cooling tower located outdoors at the northwest corner of the facility removes heat absorbed by the secondary water.
Secondary water is gravity fed from the bottom of the coolitig tower through an 8.0-in. diameter sch 40 suction pipe down to the se ondary pump. Discharge from the pump is through an 8,0-in, diameter sch 40 pipe that is direct 6d up onto the roof and later penetrates the west wall of the equipment room. Upon entering the building, the piping is reduced down to 6-in diameter piping and enters the top of the heat exchanger. On entering the heat exchanger, secondary coolant flows downward and across une side of a series of heat transfer plates to exit at the bottom on the opposite side. Primary coolant flowing on the otSer sides of the heat transfer plates removes the heat from the reactor tank. After exiting the heat exchanger, the heated secondary water returns to the cooling tower where this heat is dissipated to the atmosphere.
The normal mode of operation for the secondary cooling system is to be running continuously during normal reactor operation. Temperature controlis automatic and is described in section 1.3 below. Secondary system pressure is set by the throttling of valve SC 7 to ensure that the secondary system pressure leaving the primary to secondary heat exchanger is higher than the primary pressure entering the heat
- exchanger. The throttling of SC-7 also controls secondary system flow-rate.
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, ;. (g,; (4 ; y y Total secondary volume (est.) 2218 gallons The normal secondary system flow-rate is 900 (+/ 100) gpm Indicated.
Secondary system delta T during normal operation at 2 MW is 15 'F.
Tho main components of the secondary cooling system are listed below and described in Sections 1.1 through 1.5.
1.1 Primary to Secondary Heat Exchanger 1.2 Secondary Coolant Pump 1.3 Cooling Tower 1.4 Chemical Addition System 1.5 Piping and Miscellaneous Components 1
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1.1 PRIMARY TO SECONDARY HEAT EXCHANGER The primary to secondary heat exchanDer is an Armstrong model PFX 60 single pass, plate and frame, diagonal flow, radiator type heat exchanger. Prhnary coolant enters the bottom of the heat exchanger, flows upward and across one side of a series of heat transfer plates and exits at the top on the opposite side. Secondary coolant enters at the top of the heat exchanger, flows downward at:foss the other side of the plates and exits the heat exchanger at the bottom on the opposite side.
1.2 SECONDARY COOLANT PUMP The secondary coolant pump is a Myers brand, model ES 1250A, centrifugal purnp. It is driven by a Baldor 40 HP, 460 volt, 3 phase, and 60-hertz motor and rotates at 1760 RPM. This pump is capable of 1000 GPM at 100 f t. of head.
1.3 COOLING TOWER Heat transferred from the primary cooling system to the secondary is removed from the secondary by the cooling tower. The cooling tower (Baltimore Aircoil Co. BAC model 3586S) has the capacity to lower the temperature of 1000 GPM of recondary water from 101*F to 81*F. Secondary water intering at the side of the cooling
' tower flows through the Balance Clean Chamber / Strainer assembly up through the
- water distribution piping and into the Hot water distribution basins at each end on top of the tower. Water then flows down the wet deck (baffles) and into the sump. A ball float opens the make up water valve if the sump level gets too low. An ove low line is provided to drain to the cooling tower drain hysttn should the sump level get too bluh.
The fan in the cooling tower is belt driven by a 30 HP, single speed,1800 RPM,460 VAC, tetally enclosed air over fin motor, through a singlo shaft. Control of the cool'ng tower fan is by a thermocouple in the primary outlet piping from the heat exchanger.
When the water returning to the reactor tank exceeds 29'C (84'F) the cooling tower fan starts and air is drawn across the water flowing from the baffles to the sump.
When the nter returning to the reactor tank falls below 19'C (60'F) the cooling tower ian will stop. Automatic temperature controlis achieved through the use of a Chromalox model 3910 controller that has an adjustable set point with a preset dead-band of 10*f: (the current set-point is 2415'C).
Evaporation rate from the cooling tower is determined from the following equation provided by the cooling tower manufacturer; Evaporation rate = Water flow rate x Range (AT 'F) x .001
= 900 gpm x 15 'F x .001 ER = 13.5 gpm The makeup water source to the secondary system is the McClellan AFB $ eter supply (commonly called city water). As such, the volume of makeup water is essentially 2
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o unlimited. The flow rate of the makeup water supply is sufficient to maintain the desired cooling tower sump water level during full power operation while the chemical system blow-down (bleed) is in progress. This estimated flow rate is at least 25.5 gpm.
1.4 CHEMICAL ADDITION SYSTEM in cooling towers, cooling is accomplis' eci by evaporation of a portion of the process water as it flows through the tower. As this water evaporates, the impurities present in the supply water remain in the recirculating water. The concentration of the dissolved solids increases rapidly and can reach unacceptafi levels. in addition, airborne impurities are often introduced into the recirculating water, intensifying the problem, if these impurities are not effectively controlled, thay can cause scaling, corrosion, and sludge accumulations that reduce heat transfer officiency and increase system-operating costs.
The chemical and make-up systems replace the water lost through evaporation in the cooling tower as well as regulating the chemistry of the secondary water. Chemical control of the secondary water is designed to prevent scale deposits and algae growth in the secondary cooling equipment (pipes, cooling tower, pump, etc.), and includes a chemical metering pump and a chemical mix tank. Measuring the conductivity of the secondary wt.ter with a conductivity instrument monitors the amount of total dissolved solids in the secondary water. The maximum delred total dissolved solids is set on the locally mounted conductivity controller and whcn the set point is exceeded, a solenoid valve opens and dumps some secondary water to the industrial waste drainage system. As water is drained from the secondary, the coolirg tower sump level lowers and water from the makeup water system is automaticaly added. The controller also starts the chemical addition pump and tdds chemicals to the cooling tower. The addition pump will continue to operate until the conductivity falls below the predetermined set points on the conductivity controller control panel or it times out. In addition, periodically the cooling tower is completely drained, cleaned and refilled, which also results in lower conductivity values.
Secondary system blow-down flow-rate to the industrial waste (IW) system is approximately 12 gpm. Volume of secondary water discharged to IW system is not monitored. The frequency of blow downs to the iW system is also not monitored but is automat!cally controlled by the conductivity controller described above.
1.4.1 TREATMENT CHEMICALS The Secondary System uses 2 different chemicals for the control of impurities and algae growth.
For the prevention of the formation of hard scales (i.e. plated out silicates) on the internal surfaces of the secondary system, a mixture of sodium hydroxide and phosphoric acid is used. This chemical mixture usually arrives in 55-gallon polyethylene drums and is transferred to another 55-gal chemical addition tank for automatic use. This chemicalis called product 6324A and is supplied by the company CH2O International.
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- l For the control of alga growth and slime, a different compound (fquid) in used. This '
chemical is called Glutataldehyde (1,5 Pentanedial) under the brand name BioMax 15 and is also provided by CH2 O International. If renuired, this chemical is batch added to the coolir'g tower sump. Chemical additlos. are calculated following the label l gt.idelines.
1.6 PIPING AND MISCELLANEOUS COMPONENTS The secondary piping is 8 inch, galvanized steel to minimize corrosion. Flexible couplings installed throughout the system reduce piping stresses caused by mechanical shockr to the system. A "Y"-type strainer on the inlet of the secondary
, pump prevents foreign material from entstring and damaging the secondary puri.p and fouling the heat exchang.tr.
The main system valves, SC .1, 2, 4, and 7, are 6 in, flapper valves with manual-operators. Valves SC. 5 and 6 are 6 in. flapper valves with manual operetors. All these valves are made of galvanized stee'. All other components in the secondary system are either aluminum, stainless, or galvanized to minimize corrosion of senndary system components.
The Cooling Tower drtsin system consists of a 300 gallon poly tank connected to the cooling tower overflow line and the cooling tower drain line (SC 19) An internal float switch assembly (2 floats) is used to start /stop the drain pump (when in automatic) to pump down the tank into the in+1strial waste system.
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QUESTION 2: ,
Provide a description of the typical annual chemical usage at the facility. This sbould include a summary of any laboratory chemicals and reagents, cleaning supplies, blocides, and water treatments.
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. sodium hydroxide and phosphoric acid (secondary scale inhibitor) 2268 liters Buffer pH4 UM
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[6aTuffT212PJnWF9MehMMM5134 Buffer pH10 lPENM 6 liter M T E @ N " N E M E M iT f d 3tEWMMS
- leopropyl alcohol 4 liters n
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t QUESTION 3:
4 Describe the f acility water supply and the industrial waste system, e
The facility . sf eup water supply is provided by the McClellan Air Force Base weter system.
The industrial waste system on McClellan AFB consists of a complex series of underground pipes that go to the Base waste treatment plant.
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- 4. Provide an estimate of the annual volume and activity of solid rad w ute produced by the facility and describe its handling, storage, and transportation ofi 9e.
Response: See SAR Sections 11.1.1.3,11.2.1,.11.2.2,11.2.2.3 ard i 1.2.3.
- 5. Provide an estimate by radionuclide of the annual volume and activity ofliquid effluents produced by the facility.
Response: See SAR Section i1.2.2.2.
- 6. Provide an estimate of the expected release rates for gaseous efiluents from the facility.
Response: See SAR Section 11.1.1.1.4 and Appendix A.
- 7. Provide an estimate by radionuclide of the annual gaseous ellluents released from the facility.
Response: See SaR Section i1.1.1,4 cnd Appendix A (approximately 84 Ci/yr AR-41 based on IE-06 p Ci/mi stack release concentration).
- 8. Summarize the annual occupational radiation exposure at the facility.
ii;esconse: See SAR Section 11.1.5.6.1.
- 9. Provide a description of the facility health physics and environmental monitoring program.
Response: See SAR Sections 11.1.2 and 11.1.7.
- 10. Provide a detailed facility and site description.
Response: See SAR Chapter 2.0.
1 Question 11:
Provide a description of facility operation, including total hours of operation, hours of operation at full power, and number of kilowatt-hours per year.
- The facility is designed to operated twenty-four hours per day, seven days a week. At the present time the facility is operated twenty-four hours per day, five days a week.
- Total hours of operations as of 9-30 97 Total MW-HRS as of 9 30 97 12,352 8731 4
&l MNRC REACTOR HOURS OF OPERATION 1997 i:8"! ' '
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- 12. Briefly, provide the information required by 10 CFR 51.45, including environmental considerations, analysis, status of compliance, and any adverse information.
Response: See Appendix A l
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APPENDIX A i
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