ML14070A061
| ML14070A061 | |
| Person / Time | |
|---|---|
| Site: | 05000083 |
| Issue date: | 02/18/2014 |
| From: | Shea B Univ Of Florida, Gainesville |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML14070A061 (36) | |
Text
UFUNIVERSITY 9fCollege of Engineering PO Box 118300UF Training Reactor Facility Gainesville, FL 32611-8300 352-392-2104 bshea@ufl.edu February 18, 2014U.S. Nuclear Regulatory Commission 10 CFR 2.109(a)
New LicenseATTN: Document Control Desk UFTR Operating License R-56, Docket 50-83Washington, D.C. 20555-0001
Subject:
UFTR Responses to Request for Additional Information (ML113560528)
Attached are additional UFTR licensing basis documents in response to the RAIs datedJanuary 6, 2012. The attached documents include Chapters 1, 3, 5, 6, 8 and 11 of the FSAR.The UFTR licensing basis reconstitution efforts continue with remaining FSAR chapters andrevised Operator Requalification program to be submitted at a future date.This submittal has been reviewed and approved by UFTR management and by the ReactorSafety Review Subcommittee.
I declare under penalty of perjury that the foregoing and attached are true and correct to myknowledge.
Executed on February 18, 2014.Brian SheaReactor Managercc: Dean -College of Engineering Reactor Safety Review Subcommittee Facility DirectorReactor ManagerLicensing EngineerNRC Project ManagerThe Foundation for The Gator NationAn Equal Opportunity Institution CHAPTER 1THE FACILITY 1-2Rev. 0Rev. 0Rev. 0Rev. 0211 812014211 812014211 812014211 812014ChaPte r 1 V OWj, pag esRev. 0 2/18/2014 i
Rev. 0 2/18/2014 TABLE OF CONTENTSTHE FACILITY1.1 Introduction 1.2 Summary and Conclusions on Principal Safety Considerations 1.3 General Description 1.4 Shared Facilities and Equipm ent ----------------................
.......1.5 Comparison with Similar Facilities 1.6 S um m ary of O perations
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1.7 Compliance with the Nuclear Waste Policy Act of 1982 ----------
1.8 Facility Modifications and History1-11-11-1I-11-21-21-2...................-21-2LIST OF TABLES1-1 Brief Chronology of Key Dates and Events in UFTR History....... .1-2ii Rev. 0 2/18/2014 I The Facility1.1 Introduction This Safety Analysis Report (SAR) supports an application for license renewal to the U.S. Nuclear Regulatory Commission (NRC) by the University of Florida for the utilization of its modified Argonaut type reactor.The reactor is owned and operated by the University of Florida for the purpose of training and research including neutron irradiation services for a wide variety of scientific applications.
The reactor is known as the University ofFlorida Training Reactor (UFTR).The information and analyses presented show that the UFTR can continue to be operated at 100 kW (thermal) ratedpower without undue risk to the health and safety of the public.1.2 Summary and Conclusions on Principal Safety Considerations Possible failures or accident situations have been analyzed and discussed in Chapter 13, including the effects of arapid reactivity insertion, radioactive fission product release, and loss of coolant flow.The inherent safety of the UFTR is based on strong negative temperature and void coefficients combined withlimited excess reactivity which limit the peak power achievable, thus preventing fuel damage from crediblereactivity events.The operating power level of 100 kW results in a decay heat small enough that loss of cooling water does not resultin fuel damage.For the bounding case of the maximum hypothetical accident where fuel cladding is assumed to be removed, theresulting estimated doses to occupational workers and the general public are well within the annual limits given in10 CFR 20.1.3 General Description The main University of Florida campus is located in the Southwestern quadrant of the greater Gainesville areaapproximately one mile from the historic center of the city (University Avenue and Main Street).The Reactor Building is located on the main campus in the immediate vicinity of the College of Engineering and theCollege of Journalism.
The Nuclear Sciences Building is annexed to the Reactor Building.
The UFTR is owned and operated by the University of Florida under the NRC License Number R-56 (DocketNumber 50- 83). The UFTR is of the general type known as the Argonaut.
The reactor is heterogeneous in designusing low enriched uranium silicide-aluminum fuel elements in a two slab geometry.
Water is used as a coolant andalso as moderator.
The fuel is contained in MTR-type plates assembled in bundles.
The remainder of the moderator consists of graphite blocks which surround the boxes containing the fuel bundles and the water moderator.
Thebiological shield is made of cast-in place concrete with additional sections of removable concrete shielding.
Thereactor has an authorized maximum steady-state thermal power of 100 kW.Significant features of the reactor include:" four swinging-arm type control blades;° passive power excursion protection by primary coolant rupture disk; and" numerous irradiation facilities including horizontal and vertical beam ports, thermal column, shield tank,and pneumatic transfer system utilizing a horizontal throughport.
1-1 Rev. 0 2/18/2014 1.4 Shared Facilities and Equipment The UFTR is an integral part the Reactor Building and thus shares walls, water supplies, and main electrical supply.The ventilation
- systems, electrical distribution, and water distribution, are all separate.
1.5 Comparison with Similar Facilities The UFTR has been operated since 1959 so considerable safe operating experience is available for review.All similar Argonaut research reactors in the United States have been shutdown; they were located at the University of Washington, University of California at Los Angeles (UCLA), Iowa State University, and at Virginia Polytechnic Institute.
Of these, the UCLA R-I reactor design had the greatest similarity to the UFTR.1.6 Summary of Operations The UFTR utilization has been supported by a variety of usages including research and educational utilization byusers within the University of Florida as well as by other researchers and educators.
The Neutron Activation Analysis (NAA) Laboratory has favorably impacted on all areas of utilization from research projects using neutronactivation analysis to training and educational uses for students at all levels.UFTR energy generation is limited by a codified ALARA constraint on Argon-41 emissions.
The maximum annualaverage availability since the previous license renewal in 1982 was 91.5% for the period from September 1986 toAugust 1987.Shortly following conversion to low enriched fuel in 2006, the reactor entered a prolonged outage period. Reasonsfor this prolonged outage include; personnel
- turnover, primary piping replacement, security and facility
- upgrades, and license basis reconstitution in support of license renewal.Following completion of the prolonged outage, UFTR management expects to increase UFTR utilization back tohistoric highs while continuing to pursue opportunities for growth in existing and new program areas.1.7 Compliance with the Nuclear Waste Policy Act of 1982In accordance with U.S. Department of Energy (DOE) contract with the UFTR, the DOE retains title to the UFTRreactor fuel and is obligated to provide for its long-term disposal following return by the UFTR.1.8 Facility Modifications and HistoryThe UFTR has been operational since May 1959 when it was first licensed to operate at 10 kW. A brief chronology of the key dates and events in the history of the UFTR is given below.Table 1-1Brief Chronology of Key Dates and Events in UFTR HistoryDate EventMay 1959 Initial operating license issued. Licensed power limited to 10 kW.May 1959 Initial criticality of the UFTR.January 1964 Licensed power level increased to 100 kW.August 1982 Renewal of the operating license for 20 yearsJuly 2002 License renewal application submitted for new license.August 2006 Conversion to LEU1-2 CHAPTER 3DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND SYSTEMS Rev. 0 2/18/2014 Chapter 3 -Valid Pagesii3-13-2Rev. 0Rev. 0Rev. 0Rev. 02/18/2014 2/18/2014 2/18/2014 2/18/2014 Rev. 0 2/18/2014 TABLE OF CONTENTS3 DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND SYSTEMS 3-13.1 Design Criteria
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31--------------3-I 3.2 Meteorological Damage -.--------
--- 3--------------------------------------3-1 3.3 Water Damage ------------------------------------------------
3-13.4 Seismic Damage ----------
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23.5 Systems and Components
3-2ii Rev. 0 2/18/2014 3 DESIGN OF STRUCTURES, COMPONENTS, EQUIPMENT AND SYSTEMS3.1 Design CriteriaThe overall reactor building measures approximately 60 ft. by 80 ft. The current floor plan is primarily aimed for improving area utilization and control.
Some relatively minor alterations have been made to thefirst floor and the second floor of the UFTR building since its first license.
All building modifications andequipment additions were in conformance with the building codes in existence at the time. None of thesechanges is considered to impact reactor safety.The UFTR principal physical barrier to fission product release is the fuel cladding.
Because of the fuelmaterial and core design, the fuel and moderator temperature reactivity coefficients are negative assuringinherent protection.
Safe reactor operation is guaranteed by this inherently safe reactor design and bylimiting the installed excess reactivity.
Calculations presented in Chapters 4 and 13 demonstrate that thesafety limit on the temperature of the fuel will not be exceeded and that residual heat removal is notnecessary even under loss of coolant moderator.
The scenarios analyzed in Chapter 13 conservatively demonstrate that instrumented shutdown actions andbuilding confinement are not necessary to ensure that radiological doses will not exceed 10 CFR Part 20allowable limits.The UFTR coolant works at near ambient pressure and low temperatures.
The primary coolant systemtransfers the heat from the reactor to the heat exchanger.
The heat is removed by the secondary coolantsystem to the storm sewer with no mixing of water between the two systems.
The secondary system waterpressure is maintained slightly higher than the primary system. Any leakage from the secondary system tothe primary system will lead to an increase in the primary water resistivity which is detected by theconductivity cell located before the purification system. Integrity of piping is also checked through flowand level measurement instruments.
Electric power to UFTR is the same one that supplies the whole university.
The system is failsafe in designand electrical power is not needed for any active safety function.
The control blades are "fail-safe" in the sense that they will drop into the core by gravity in the event of aloss of power. The instrumentation and control systems provide a series of alarms, interlocks and reactortrips preventing the occurrence of operating situations that are outside the bounds of the normal operating procedures.
No control or safety system is required to maintain a safe shutdown condition.
3.2 Meteorological DamageStorm surges and seiches do not occur in Alachua County. Hurricane force winds and tornadoes have arelatively low probability of occurrence in Alachua County and since the UFTR is a self-protected andisolated low-power system with a low fission-product inventory, no further criteria were established for theUFTR structure.
3.3 Water DamageFrom accumulated experience at the UFTR site, it has been established that no flooding conditions willexist within the Reactor Cell from an accumulated precipitation of 8" of rainfall in a 24-hour period. In theunlikely event that the National Weather Service gives a significant probability of a hurricane or othersevere storm to produce an accumulated rainfall of more than 8 inches of rain in a 24-hour period, UFTRpersonnel will proceed according to an approved procedure for addressing potential (or actual) floodingconditions.
3-1 Rev. 0 2/18/2014 3.4 Seismic DamageAs stated in Chapter 2, Florida is a relatively inactive area for seismic activity and therefore no criteria forearthquakes have been established for the UFTR structure.
3.5 Systems and Components The UFTR does not have structures, components, or systems that are safety-related or important-to-safety in the same context as nuclear power plants. For the UFTR, a failure of the protection system or credibleevent does not have the potential for causing off-site exposures greater than the normal exposure limits of10 CFR Part 20. However, the UFTR structure was designed to withstand natural phenomena as previously discussed.
3-2 CHAPTER 5REACTOR COOLANT SYSTEMS Rev. 0 2/18/2014 Chapter 5 -Valid Pagesi Rev. 0 2/18/2014 ii Rev. 0 2/18/2014 5-1 Rev. 0 2/18/2014 5-2 Rev. 0 2/18/2014 5-3 Rev. 0 2/18/2014 5-4 Rev. 0 2/18/2014 i
Rev. 0 2/18/2014 TABLE OF CONTENTS5 REACTOR COOLANT SYSTEMS5.1 Sum m ary D escription
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5.2 Prim ary C oolant System --------------------------------------
5.3 Secondary Coolant System -----------------------------------
5.4 Primary Coolant Cleanup System5.5 Primary Coolant Makeup Water System5 .6 N -16 S h ield ing .....................
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5 ---------------
5 -1.................
5-15-25-25-2LIST OF FIGURES5.1 UFTR Primary Coolant Loop and Purification System..5.2 UFTR Secondary Water Cooling System ..........
5-35-4ii Rev. 0 2/18/2014 5 REACTOR COOLANT SYSTEMS5.1 Summary Description This chapter describes the UFTR cooling system and its various components.
Demineralized light water isused in the UFTR to moderate fast neutrons and to maintain low coolant temperatures when it's operating at or near rated power for extended periods.
During normal operation, this cooling is accomplished viaforced convection through the open primary system with waste heat disposed to the environment via thesecondary coolant system. Due to the simplicity of design and low power of the UFTR argonaut typereactor, this chapter is greatly simplified from what is required for a typical reactor.5.2 Primary Coolant SystemThe reactor primary coolant water flow path originates from the coolant storage tank through the heatexchanger to the bottom of the fuel boxes, upward past the fuel assemblies to overflow pipes and into aheader for return to the storage tank. This is shown schematically in Figure 5-1.The major components of the reactor coolant system include:* Coolant Storage Tank -The primary coolant is stored in the coolant storage tank that has acapacity of 200 gallons of water, approximately six (6) times the capacity of the reactor." Primary Coolant Pump -Rated at 65 gpm, the primary coolant pump draws suction from theprimary storage tank and circulates the water through the heat exchanger before delivering it to thefuel boxes. Normal flow is about 46-48 gpm. Flow from the coolant storage tank is controlled by aball valve in the pump discharge line." Heat Exchanger
-The heat exchanger is a 316 stainless steel water-to-water tube and shell heatexchanger, one pass on shell side and 4 passes on primary side, designated to circulate up to 250gpm of secondary water through the shell side and up to approximately 75 gpm of reactor coolantwater through the tube side for removal of up to 500 kW thermal.
The tubes are seal welded to thetubesheet to minimize leakage." Dump Valve -The Dump Valve is a solenoid-operated valve that opens automatically whenactuated by a demand or trip signal, allowing water in the fuel boxes to drain into the coolantstorage tank. Prior to reactor operation, the dump valve is shut and the primary coolant pump isstarted to supply the necessary moderation and cooling for full-power reactor operation.
" Core Water Level Indicator
-Core water level is indicated by sight glass. A level switch locatedwith the sight glass is wired to the reactor protection system actuating a reactor trip when thewater level in the core falls below the preset limit." Rupture Disk -A graphite rupture disk is designed to burst at approximately 2 psi above thenormal operating system pressure.
Should a pressure excursion occur, this diaphragm wouldrupture causing the water from the core to be drained into the equipment storage pit.5.3 Secondary Coolant SystemA schematic diagram of the secondary cooling system of the UFTR is shown in Figure 5-2. There are twosources of water for this secondary cooling system: the deep well used for most operations and the citywater line used as a back-up system during operation above I kW (thermal).
The well water is pumped by asubmersible, 10 horsepower pump.5-1 Rev. 0 2/18/2014 The deep well is approximately 238 ft deep with a casing diameter of 3" with the static water levelapproximately 87 ft. below grade. The well pump has approximately 200 gpm pumping capacity for thisarrangement.
The well water flows through a basket strainer then into the shell side of the heat exchanger and subsequently into the storm sewer.A flow-measuring instrument located on the input line for the heat exchanger monitors the secondary flowrate. At predetermined setpoints, dependent on the secondary water source and power level, warningsignals and trips are transmitted to the control room.Pressure of the secondary coolant system is maintained higher than the primary system to preventcontamination of secondary water, although secondary coolant is not required until I kW. The secondary coolant system is tested for radioactive contamination weekly according to written procedures.
5.4 Primary Coolant Cleanup SystemThe primary purification system loop is also shown in Figure 5-1. This loop is supplied with a separatepump allowing continuous purification flow. The flow of the primary coolant pump is sufficient tomaintain a flow through the purification loop when it is in operation.
The purification system is arranged to provide the reactor with continuous monitoring of the resistivity ofthe primary water. Nuclear type resin (H-OH; pH control; AMBERLITETM or equivalent) is used in thepurification system demineralizer.
An in-line resistivity bridge is set up to accept two conductivity cellsignals -one upstream of the demineralizer and one downstream.
5.5 Primary Coolant Makeup Water SystemDemineralized water is used as makeup to the primary coolant system and the shield tank through a hoseconnection.
The makeup system consists of demineralizers, connected to the city water system, filled withH-OH nuclear type resin.5.6 N-16 Shielding Portions of the primary coolant system that are subject to coolant flow are located in the primary equipment pit or, in the case of the fuel boxes, in the center of the core shielding structure.
For operation at I kW orabove, concrete block shielding is added to the top of the equipment pit. Entry into the equipment pit ispermitted no sooner than 15 minutes after shutdown from power operation to allow time for N-I 6 decay.5-2 Rev. 0 2/18/2014 No. 1-3 No. 4-6LEVEL INDICATOR DEMINERALIZER Figure 5-1 UFTR Primary Coolant Loop and Purification System.5-3 Rev. 0 2/18/2014 Plowmeter oatoValveBasketStrainerCheekValveTotalPlowReliefValveCity WaterSBackflow
[Figure 5-2 UFTR Secondary Water Cooling System5-4 CHAPTER 6ENGINEERED SAFETY FEATURES(The UFTR does not have any creditedEngineered Safety Features)
CHAPTER 8ELECTRIC POWER Rev. 0 2/18/2014 Chapter 8 -Valid Pagesi Rev. 0 2/18/2014 ii Rev. 0 2/18/2014 8-1 Rev. 0 2/18/2014 i
Rev. 0 2/18/2014 TABLE OF CONTENTS8 ELECTRICAL POWER SYSTEMS8.1 Normal Electrical Power Systems8.1.1 AC Power Systems ........8.1.2 DC Power Systems8.2 Emergency Electrical Power Systems ...8-18-1........
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8 18-1ii Rev. 0 2/18/2014 8 ELECTRICAL POWER SYSTEMSThe UFTR does not generate electric power. Since the UFTR does not generate electrical power, there is no impacton the power grid. The design of the UFTR ensures the reactor is safely shutdown under a complete loss of electrical power. There is no credible accident that would lead to the release of radioactivity in case of loss of power.8.1 Normal Electrical Power Systems8.1.1 AC Power SystemsDuring operation, the electric power requirements for the UFTR will be supplied by the offsite regional utilities servicing the University of Florida.
The facility requires power of 115 V-AC at 60 Hz for the reactor console andauxiliary equipment.
The facility also utilizes 230 V-AC and 480 V-AC at 60 Hz for various motors.A loss of electrical power drops out the scram relays and de-energizes the magnetic clutches to trip the reactor bydropping the control blades under gravity completely into the core. Therefore, there is no need to consider offsitesources of emergency power.Interruptions in power from the regional utilities system occur occasionally.
Although such trips associated with lossof power are bothersome from a training or research standpoint, such a loss of power has no bearing upon the safeoperation of the UFTR system.8.1.2 DC Power SystemsThe area radiation monitors and stack monitor are powered by 24 V-DC power supplies backed up with a "floating" battery pack. Emergency DC lighting is located in various locations throughout the reactor building and the reactorcell. Additionally, there are wall mounted rechargeable hand-held flashlights at various locations within the reactorbuilding and reactor cell.8.2 Emergency Electrical Power SystemsThe UFTR is connected to a Diesel Electric Generator located in the West fenced lot area of the facility.
The DieselGenerator provides backup electrical power for all reactor systems, including the radiation monitoring and physicalprotection
- systems, as well as emergency
- lighting, except for the primary coolant system dump valve. In this way allthe monitoring systems are supplied with electric power but the reactor cannot be operated.
No credit is taken for the back-up electrical Diesel Generator for safety analysis considerations.
For additional information on the Diesel Generator refer to Chapter 9.8-1 CHAPTER 11RADIATION PROTECTION AND WASTEMANAGEMENT Rev. 0 2/18/2014 Chapter 11 -Valid Pagesi Rev. 0 2/18/2014 ii Rev. 0 2/18/2014 11-1 Rev. 0 2/18/2014 11-2 Rev. 0 2/18/2014 11-3 Rev. 0 2/18/2014 11-4 Rev. 0 2/18/2014 11-5 Rev. 0 2/18/2014 11-6 Rev. 0 2/18/2014 11-7 Rev. 0 2/18/2014 11-8 Rev. 0 2/18/2014 11-9 Rev. 0 2/18/2014 11-10 Rev. 0 2/18/2014 i
Rev. 0 2/18/2014 TABLE OF CONTENTS11 RADIATION PROTECTION AND WASTE MANAGEMENT 11--A11.1 Radiation Protection -------------------------------------------- 11-111.1.1 Radiation Sources-------------------------------------- 11-111.1.1.1 Airborne Radiation Sources11-111.1.1.1.1 Occupational Exposure from Ar-4 ! DuringRoutine Reactor Operations
1 1-111.1.1.1.2 Estimated Annual Dose in the Unrestricted Area from Ar-41 Released During RoutineReactor Operations------------------------ 11-111.1.1.2 Liquid Radioactive Sources---------------------- ---11-411.1.1.3 Solid Radioactive Sources11-411.1.2 Radiation Protection Program ------- ...................-------------------------------
11-411.1.2.1 Organization of Radiation Control Staff and WorkingInterface with Operations Staff ----------------------------
11-511.1.2.2 Radiation Control Procedures11-511.1.2.3 Radiation Protection Training-
1-511.1.2.4 Audits11-511.1.2.5 Radiation Control Records11-511.1.3 ALARA Program ----------------------------------------
11-511.1.4 Radiation Monitoring and Surveying -------------------------- 11-611.1.4.1 Radiation Monitoring Equipment --------------------- 11-611.1.4.2 Instrument Calibration 11-611.1.4.3 Routine Monitoring ----- -----------
11-611.1.5 Radiation Exposure Control and Dosimetry.---------------------- 11-711.1.5.1 Shielding 11-711.1.5.2 Ventilation 11-711.1.5.3 Entry Control and Posting Requirements
1---- 1-711. 1.5.4 Protective Clothing-
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11-711.1.5.5 UFTR Occupational Radiation Levels11-811.1.5.6 Personnel Dosimetry ---------------------
11-811.1.6 Contam ination Control ..................11-811.1.7 Environmental Monitoring --------------------------------- 11-911.2 Radioactive Waste Management ------------------------------------- 11-911.2. Radioactive Waste Controls-------------------------------- 11-911.2. 1.1 Gaseous Waste Management 11-911.2.1.2 Liquid Waste Management ------------------------- 11-911.2.1.3 Solid W aste ..................
11-9LIST OF TABLESI1-1 Summary of the UFTR Release Point Data Taken During the October 2008Semiannual Ar-41 Surveillance Measurements 211-2 Wind Summary for January 1, 1980 to December 31, 2009 for the Gainesville Regional Airport as Reported by NOAA Online Climate Data (Ref 11-5) ------------
11-311-3 Maximum Expected Annual Dose in the Unrestricted Area from Ar-41 ReleasedDuring Routine Reactor Operations
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11-411-4 Radiation Monitoring Equipment
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11-611-5 Typical Gamma Radiation Levels in the Reactor Cell at Full-Power
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11-8References 11-10ii Rev. 0 2/18/2014 I1 RADIATION PROTECTION AND WASTE MANAGEMENT 11.1 Radiation Protection 11.1.1 Radiation Sources11.1.1.1 Airborne Radiation SourcesAs described in Chapter 9, the design of the reactor cell ventilation systems ensure that leakage andaccumulation of radioactive gases into the reactor cell is prevented by drawing air from the cell, throughthe reactor and out the exhaust stack.The only radioisotope of concern is the Argon-41 produced in the UFTR as a result of neutron activation ofthe Argon-40 in the air drawn in through the crevices in the concrete and the graphite reflector.
The othergaseous components of air are either too rare, have small activation cross sections, or produce activated products having half-lives too short to be of significance.
11.1.1.1.1 Occupational Exposure from Ar-41 During Routine Reactor Operations The only routine occupational exposure from Ar-41 occurs during performance of stack effluentsurveillance measurements involving manual grab samples of stack effluent.
This surveillance has asemiannual frequency and surveillance related exposures are kept ALARA and well within 10 CFR 20limits.11.1.1.1.2 Estimated Annual Dose in the Unrestricted Area from Ar-41 Released During RoutineReactor Operations Regulation 10 CFR 20.1101(d) imposes an ALARA constraint on airborne emissions of radioactive material to the environment such that the individual member of the public likely to receive the highest dosewill not be expected to receive a total effective dose equivalent (TEDE) in excess of 10 mrem per year fromthese emissions.
This constraint ensures that dose from airborne emissions make up no more than 10% ofthe 100 mrem per year limit of 10 CFR 20.1301(a)(1) and therefore this analysis will focus on ensuringcompliance with the ALARA constraint.
While, in principle, the dose resulting from the release of radionuclides to the atmosphere can bedetermined by environmental monitoring, at the low levels consistent with the limit of the constraint, it isnot reasonable to distinguish the portion attributable to UFTR Ar-41 emissions from that which is due tobackground radioactivity.
Therefore, an expected dose must be determined analytically.
To ensure compliance with the annual TEDE constraint of 10 CFR 20.1101(d),
the UFTR limits Ar-41produced by administratively limiting effective full-power hours of operation (EFPHs).
Periodicsurveillance measurements of the stack effluent are performed to determine instantaneous Ar-41concentration.
Based on this instantaneous concentration and stack release point parameters, a monthlyEFPH limit is calculated to ensure compliance with the annual TEDE constraint of 10 CFR 20.1101(d).
Prior to reactor operation, the cumulative EFPHs for the month are compared to this monthly limit toprevent exceeding the monthly limit.The air concentration at any point in the environment is an extremely complex function of the quantity ofthe radioactive material
- released, the configuration of the facility from which the material is released, thedistance from the point of the release to the locations of interest, the meteorological conditions, and variousdepletion processes which remove the radioactive material from the effluent plume as it moves from thepoint of release to the location of the receptor.
To avoid excessive conservatism which result in furtherconstraints on UFTR energy generation, this complexity necessitates the use of a computer code.Additionally, consistent with the low level specified by the ALARA constraint, the UFTR has determined that the effort and expense of implementing a detailed site specific environmental model are not practical orreasonable.
11-1 Rev. 0 2/18/2014 Diffusion and atmospheric turbulence are the primary processes acting to reduce the Ar-41 concentrations in the plume. The degree of dilution resulting from atmospheric turbulence and diffusion depends upon thestability of the atmosphere, the joint frequency distribution of wind speed and direction, and the distancefrom the point of release to the location of the receptors.
Additional factors that influence dilution includethe height at which the release occurs, the rise of the effluent plume due to the momentum and/or thermalbuoyancy of the gases in the effluent, and the relationship between the height of the release and the heightsof the building from which the release occurs and surrounding structures.
When determining average concentrations over a long time period such as the annual average airconcentrations of interest, assuming a neutral atmospheric stability is appropriate (Ref 11-4). For the casewhere atmospheric stability is neutral, the distance from the source to the point of maximum concentration can be calculated (Ref I-1).Based on the discussion above, the distance to the most exposed member of the public will be calculated and compliance with the constraint limit will be demonstrated using the NRC endorsed computer codeCOMPLY (Ref 11-3).The computer code COMPLY assesses dose from airborne releases using varying amounts of site-specific information in four screening levels. In Level 1. the simplest level, only the quantity of radioactive materialpossessed during the monitoring period is entered.
At Level 4., the COMPLY code produces a morerepresentative dose estimate and provides for a more complete treatment of air dispersion by requiring thegreatest amount of site-specific information (Ref 11-3).The UFTR discharges Ar-41 through an exhaust stack approximately 9.1 meters above ground level. Basedon the most recent surveillance measurements in October 2008, the emission rate of Ar-41 in the stackeffluent is 1.351E-04 Ci/s (Ref 11-2). A summary of the October 2008 surveillance measurements isprovided in Table 11-1.Table 11-1Summay of the UFTR Release Point Data Taken During the October 2008 Semiannual Ar-41Surveillance Measurements Core Vent Flow 0.10384 m-/sStack Dilution Flow 6.3281 m3/sAr-41 Concentration 2.100E-05 Ci/m3Total Stack Velocity 10.896 m/sThe maximum ground level concentration occurs on the plume center line at the downwind distance asfollows (Ref I 1-1):heo Yz = V t 2where:az = vertical deviation of plume contaminant (m);The effective stack height (he) can be calculated from the following equation (Ref. 11-1):he = h + d(vS)14911-2 Rev. 0 2/18/2014 where:h = physical stack height (9.1 m);d = stack diameter (0.876 m);v, stack effluent velocity; andV = mean wind speed (m/s).The distance (x) at which the maximum concentration occurs can then be determined by solving forIx' given the vertical diffusion parameter determined previously from the effective stack height using (Ref11-4):1S = (0.06x) V(1 + 0.0015xwhere:x = dmax = distance from point of release to receptor (m);A 30-year wind rose is used to describe the average wind speed and wind direction.
This wind summarydata is provided in Table 11-2.Table 11-2Wind Summary for January 1, 1980 to December 31, 2009 for the Gainesville Regional Airport asReported by NOAA Online Climate Data (Ref 11-5)Direction
-From Frequency Speed (m/s)N 5.90% 3.35NNE 4.50% 3.50NE 5.20% 3.65ENE 5.20% 3.71E 7.50% 3.60ESE 4.10% 3.50SE 3.70% 3.55SSE 3.10% 3.50S 4.50% 3.60SSW 3.30% 3.76SW 3.50% 3.96WSW 4.60% 4.32W 7.50% 4.07WNW 4.90% 3.60NW 4.60% 3.40NNW 3.80% 3.29Calm 22.60% 0.00Variable 1.60% 2.11Mean Wind Speed 2.8111-3 Rev. 0 2/18/2014 Using the COMPLY computer code, the maximum expected TEDE, signified as TEDEmax, received by themost exposed member of the general public located at dmax may now be estimated.
The result of calculating the annual TEDE to the general public from routine releases of Ar-41 into the unrestricted area is given inTable 11-3.Table 11-3Maximum Expected Annual Dose in the Unrestricted Area from Ar-41 Released During RoutineReactor Operations 11 he dm.X TEDEmac(m/s) (m) (m) (m) (mrem)2.81 14.9 10.6 202 19.5It should be noted that in order to receive the dose shown in Table 11-3, an individual would be required tocontinuously occupy the specified location (202 meters from the release point) for a full year while thereactor operated continuously for a year.The calculated dose shows that the maximum expected Ar-41 concentration at the location of the mostexposed member of the public results in greater than the ALARA constraint of 10 mrem/year but remainswell within the 100 mrem/year limit of 10 CFR 20.1301(a)(1).
As discussed previously, the UFTR calculates a monthly EFPH limit based on surveillance measurements to ensure compliance with the annual TEDE constraint of 10 CFR 20.1101(d).
Based on the measurements taken during the October 2008 performance of this surveillance and the associated TEDE result in Table1 -3, the UFTR is limited to 375 EFPHs per month.This choice of ALARA constraint as the analysis limit, in combination with associated Technical Specifications, conservative occupancy assumption, and analysis above, provide reasonable assurance thatdose resulting from UFTR Ar-41 emissions will meet the ALARA constraint of IOCFR20.1 101(d) and bewell within the limit of IOCFR20.1301(a)(1).
11.1.1.2 Liquid Radioactive SourcesNeutron activation product impurities in the primary coolant represent the only liquid radioactive materialroutinely produced during normal reactor operations.
The majority of these impurities are removed fromthe primary coolant by the purification loop.11.1.1.3 Solid Radioactive SourcesThe solid radioactive sources associated with the normal operation of the UFTR are the fuel, neutronstartup sources, fission chambers, solid wastes and activated materials.
11.1.2 Radiation Protection ProgramIncreased utilization of ionizing radiation at the University of Florida led the administration to establish aUniversity-wide Radiation Control Program in the early 1960's. The primary purposes of this program areto assure the radiological safety of all University personnel, to assure that ionizing and nonionizing radiation sources are procured and used in accordance with Federal and State regulations, and to assure thatradiation exposures are "as low as reasonably achievable" (ALARA).
To assure these ends, the Radiation Control and Radiological Services Department was established under the Division of Environmental Healthand Safety and headed by the Radiation Control Officer (RCO).The Radiation Control Committee has designed procedures and policies in the form of a document entitled"Radiation Control Guide," in an effort to provide investigators using ionizing radiations with guidelines 11-4 Rev. 0 2/18/2014 necessary to maintain their facilities in a manner that keeps exposures ALARA. These procedures areconsistent with regulations of the Nuclear Regulatory Commission and the Florida Department of Health;they are applicable to all facilities under the administration of the University of Florida including the UFTRfacility.
In addition to University-wide radiation protection
- policies, the UFTR has embedded radiation protection and ALARA requirements into the UFTR Standard Operating Procedures.
11.1.2.1 Organization of Radiation Control Staff and Working Interface with Operations StaffDetails on the organizational structure, reporting
- pathways, and working interface can be found in Chapter12.11.1.2.2 Radiation Control Procedures In addition to University-wide radiation protection
- policies, the UFTR has embedded radiation protection and ALARA requirements into the UFTR Standard Operating Procedures.
While not intended to be all-inclusive, the following is a list of typical radiation control procedures incorporated into the UFTRStandard Operating Procedures:
" Radiation Protection and Control;" Radiation Work Permits;" Primary Equipment Pit Entry;* Removing Irradiated Samples from UFTR Experimental Ports;* Control of UFTR Radioactive Material Transfers; and* Circulation,
- Sampling, Analysis, and Discharge of Holdup Tank Wastewater.
11.1.2.3 Radiation Protection TrainingUnescorted facility staff and researchers receive training on radiation protection and on the techniques foravoiding, limiting and controlling exposure commensurate with their risk and sufficient for their work orvisit. Facility operations personnel are trained and qualified on radiation control through the UFTRRequalification and Recertification Training Program.11.1.2.4 AuditsThe UFTR Reactor Safety Review (RSRS) Subcommittee reviews and audits reactor operations for safety,ensuring radiological safety at the facility.
Details can be found in Chapter 12.11.1.2.5 Radiation Control RecordsDetails on the records requirements can be found in Chapter 12.11.1.3 ALARA ProgramThe University-wide ALARA policy is embedded as an integral part of the UFTR Standard Operating Procedures.
The D-series of SOPs describe the general radiation protection requirements and limits that must beobserved to assure radiation exposures are kept ALARA per the University-wide ALARA policy. Specificprocedures to be followed during maintenance operations are included in the E-series of SOPs. Specificprocedures and radiation limits related to fuel handling operations are included in C-series SOPs.Radioactive waste handling and shipment are also addressed in D-series SOPs.11-5 Rev. 0 2/18/2014 11.1.4 Radiation Monitoring and Surveying 11.1.4.1 Radiation Monitoring Equipment UFTR radiation monitoring equipment is summarized in Table 11-4. This equipment is updated andreplaced as needed and therefore this equipment list should be considered representative only.Table 11-4Radiation Monitoring Equipment Item Location FunctionStack Monitor Effluent Stack Airborne particulate and gasArea Radiation Monitors Various locations in Reactor Cell General area radiation fieldsAir Particulate Detector Reactor Cell ground floor Airborne particulate Portable Air Sampler Various Airborne particulate Portal Monitor Reactor Cell entrance Personnel contamination Portable Ion Chamber Survey Various Beta/Gamma exposure ratesMeterPortable GM Survey Meter Various Beta/Gamma exposure ratesPortable Pancake Probe GM Various Beta/Gamma contamination Survey MeterPortable Neutron Survey Meter Various Neutron dose ratesPortable Micro-R Survey Meter Various Gamma exposure ratesHPGe Gamma Spectroscopy NAA Lab Gamma spectroscopy SystemGas Flow Proportional Counter NSC Rm. 106 / NAA Lab Alpha/Beta activitySelf-Reading Pocket Dosimeters Various Gamma exposure estimates TLDs Various Environmental and personnel exposures 11.1.4.2 Instrument Calibration Technical Specification required radiation monitoring systems are calibrated in accordance with Technical Specification requirements.
Other radiation instruments, such as portable survey meters, are calibrated using local procedures based on ANSI N323-1978.
Instruments not calibrated locally are sent to anappropriate calibration facility.
11.1.4.3 Routine Monitoring The radiation survey program is structured to make sure that adequate radiation measurements of bothradiation fields and contamination are made commensurate with the amount and type of work beingperformed with radioactive material.
The intent of such surveys is to prevent uncontrolled release ofradioactive material and to minimize exposure.
This program includes, but is not limited to:Surveys performed on a weekly basis include swipe surveys, air and water samples, and gamma radiation field surveys.
Surface contamination in the room is determined by means of portable instruments and smeartests. Particular attention is given to the equipment pit, experimental areas and the irradiated fuel storagepits during each survey. There is an ongoing program by the Radiation Control Office and the UFTRfacility staff to monitor radiation levels outside the UFTR building in the nearby vicinity.
11-6 Rev. 0 2/18/2014 Periodic surveys are performed to check for leakage around beam plugs and through the stacked-block reactor shield; periodic air samples are also taken and analyzed providing a check on the proper functioning of the continuous air monitoring (CAM) system which uses one or more air particulate detectors.
Thecoolant is checked by evaporating a sample to dryness and counting with a gas flow proportional orequivalent counter.11.1.5 Radiation Exposure Control and Dosimetry The UFTR facility is of the modified Argonaut type., designed to minimize radiation exposure to allindividuals.
Since the reactor is used as a teaching tool and for research operations, a more stringent safetyprogram has been developed to ensure radiation exposures meet the ALARA criterion; UFTR StandardOperating Procedures (SOP's) are designed to facilitate the minimization of exposure rates and to ensurethe health and safety of the people in and around the facility.
11.1.5.1 Shielding During normal operation at the 100 kWth rated power level, the shielding is sufficient for the entire "core"and activation (biological shield) sources of radiation discussed.
At full-power, typical radiation levelswithin the reactor cell are I to 2 mR/hr or less.Additional shielding is available in the form of cast concrete blocks, lead bricks, shield casks, smallconcrete blocks and sheet shielding materials which can be used as shielding during experiments, maintenance activities, and around activated sources.
Radiation surveys are conducted for routineexperiments to determine whether special shielding configurations are needed to meet the ALARAstandard.
When experimental requirements necessitate operation of the reactor with a shield plug removed, stricthealth physics supervision is required.
All such experiments are approved in advance by the ReactorManager and the UFTR RSRS if deemed necessary based on experiment class. Adequate shielding must beprovided as specified in the applicable procedures, to assure that ALARA criterion and safetyconsiderations are satisfied.
All samples activated in the reactor are removed as specified in applicable procedures.
Additional shielding in the form of lead bricks and concrete blocks is available for any activated sources removed from theexposure facilities.
In addition, a hot cave with remote handling facilities is available in the radiochemistry laboratory outside the reactor cell.11.1.5.2 Ventilation The UFTR ventilation systems are described in FSAR Chapter 9.11.1.5.3 Entry Control and Posting Requirements In accordance with the regulations found in 10 CFR 20, the UFTR has multiple locations posted andcontrolled as radiation areas. Other areas within the UFTR are designated restricted areas. Should radiation or facility conditions change, the entry controls and postings will follow the requirements in 10 CFR 20.11.1.5.4 Protective ClothingAnti-contamination clothing designed to protect personnel against contamination is used and specified when recommended or required by work conditions.
11-7 Rev. 0 2/18/2014 11.1.5.5 UFTR Occupational Radiation LevelsExposure measurements show that both thermal and fast neutron contributions to radiation levels in the re-actor cell are typically negligible.
Typical gamma radiation levels during full-power operation are shown inTable 11-5.Table 11-5Typical Gamma Radiation Levels in the Reactor Cell at Full-Power Location Typical Radiation Level (mR/hr)Top of shield tank 15Control Console < INorth ARM IEast ARM ISouth ARM < IArea just West of Rabbit system 211.1.5.6 Personnel Dosimetry The UFTR provides personnel dosimetry to occupational radiation workers to ensure compliance with thedose limits of 10 CFR 20. Whole body badges are worn for this purpose with additional dosimetry such asextremity or ring badges if warranted due to the radiological conditions.
The Radiation Control Office maintains permanent records of dosimetry readings.
11.1.6 Contamination ControlRadioactive contamination is controlled at the UFTR by using standard operating procedures and radiation control techniques for radioactive contamination monitoring along with proper work methods.
Routineradiation monitoring is used to detect and identify contamination.
The UFTR procedures contain provisions to control contamination such as:" Personnel are required to monitor their hands and feet for contamination when leavingcontaminated areas or restricted areas that are likely contaminated.
" All personnel entering the reactor cell are required to utilize the portal monitor or hand-held frisker to check for potential contamination upon leaving the reactor cell." Materials, tools and equipment are surveyed for contamination before removal from contaminated areas or restricted areas where contamination is likely." Contaminated areas and restricted areas where contamination is likely are surveyed routinely forcontamination levels.* Potential contaminated areas are periodically monitored, consistent with the nature and quantity ofthe radioactive materials present." Radiation Work Permits (RWPs) are required to assure proper radiological protective measures areavailable and used during work which has actual or potential radiological hazard with itsaccomplishment and to provide appropriate documentation of the radiation control measures.
" Anti -contamination clothing designed to protect personnel against contamination is used andspecified in the RWPs when recommended or required by work conditions.
- Contamination events are documented in reports.* Staff are trained on the risks of contamination and on the techniques for avoiding, limiting andcontrolling contaminations commensurate with their risk.11-8 Rev. 0 2/18/2014 11.1.7 Environmental Monitoring The UFTR Environmental Radiological Program is conducted to ensure that the radiological environmental impact of reactor operations is as low as reasonably achievable (ALARA);
it is conducted in addition to theradiation monitoring and effluents control.
This program is conducted by the UFTR facility staff under thesupervision of the Radiation Control Office, to monitor radiation levels in unrestricted areas surrounding the UFTR facility.
Monitoring is conducted by measuring the gamma doses at selected fixed locations, with acceptable personnel monitoring devices.
The Luxel, TLDs or other radiation monitoring devices are then collected bythe UFTR staff or Radiation Control personnel and evaluated monthly by a qualified processor.
Typically these radiation monitoring devices show no significant indications above background for the UFTR site.11.2 Radioactive Waste Management 11.2.1 Radioactive Waste ControlsRadioactive waste is generally considered to be any item or substance which is no longer of use to thefacility and which contains, or is suspected of containing, radioactivity above the natural background radioactivity.
Radioactive waste handling and shipment are addressed in D-series SOPs.The objective of the radioactive waste management program is to ensure that radioactive waste isminimized, and that it is properly
- handled, stored and disposed of. The UFTR is a low power researchreactor and generates very small amounts of radioactive waste.11.2.1.1 Gaseous Waste Management As described in Chapter 9, the design of the reactor cell ventilation systems ensure that leakage andaccumulation of radioactive gases into the reactor cell is prevented by drawing air from the cell, throughthe reactor and out the exhaust stack.The only gaseous radioisotope of concern produced during normal operation of the UFTR is Argon-41, classified as an effluent rather than waste. Therefore, as in many other non-power
- reactors, there are nospecial gaseous waste systems necessary at the UFTR.11.2.1.2 Liquid Waste Management While normal operation of the UFTR does not produce liquid radioactive wastes, liquid resulting fromHVAC operation and sampling activities are routed to an aboveground tank in the Northwest corner of thereactor cell. Periodically the water is pumped to the above-ground Waste Water Holdup Tank, sized to hold1,000 gallons of liquid and located outside the reactor building in the West fenced area. Most of the waterheld up in the tanks comes from the air conditioning system with a small amount coming from samplingwater collected from the primary system, shielding tank, and secondary sample points. Periodic samples ofthe collected liquid waste are taken by the reactor staff and assayed to determine the total activity levelpresent.
If, as expected, activity levels are within acceptable levels for release, then the contents of the tankare released into the University of Florida Sanitary Sewage System.The D-Series of UFTR Standard Operating Procedure establishes the standard protocol for the circulation,
- sampling, analysis and discharge of wastewater to assure releases to the sanitary sewer are within the limitsset forth by the 10 CFR 20.11.2.1.3 Solid WasteSolid waste is typically generated at the UFTR from irradiated
- samples, packaging materials, contaminated gloves and clothing, used primary coolant demineralizer resin beads, filter traps on the waste water holduptank and other similar sources.
All solid wastes are collected in accordance with approved Radiation 11-9 Rev. 0 2/18/2014 Control techniques.
These solid wastes are typically very low level. Solid wastes are periodically transferred and shipped in accordance with approved UFTR Standard Operating Procedures.
References:
Il-! Slade, D.H. Meteorology and Atomic Energy -1968, TID-24190 11-2 UFTR S-4 Argon Measurement Surveillance completed on October 14, 2008.11-3 Regulatory Guide 4.2011-4 EPA 520/1-89-001 11-5 NOAA Online Climate Data Center11-10