ML13353A174

Uftr Responses to Request for Additional Information (ML113560528)

ML13353A174
Person / Time
Site:	05000083
Issue date:	12/12/2013
From:	Shea B C Univ Of Florida, Gainesville
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13353A174 (25)

Text

UFUNIVERSITY ofUFFLRDCollege of Engineering UF Training Reactor FacilityPO Box 118300Gainesville, FL 32611-8300 352-392-2104 bshea@ufl.edu December 12, 2013U.S. Nuclear Regulatory Commission ATTN: Document Control DeskWashington, D.C. 20555-0001 10 CFR 2.109(a)

New LicenseUFTR Operating License R-56, Docket 50-83

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 2 and 7 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 December 12, 2013.Brian SheaReactor Managercc: Dean -College of Engineering Reactor Safety Review Subcommnittee Facility DirectorReactor ManagerLicensing EngineerNRC Project ManagerA-uzbThe Foundation for The Gator NationAn Equal Opportunity Institution CHAPTER 2SITE CHARACTERISTICS Rev. 0 12/12/2013 Chapter 2 -Valid Pagesi Rev. 0 12/12/2013 ii Rev. 0 12/12/2013 2-1 Rev. 0 12/12/2013 2-2 Rev. 0 12/12/2013 2-3 Rev. 0 12/12/2013 2-4 Rev. 0 12/12/2013 2-5 Rev. 0 12/12/2013 2-6 Rev. 0 12/12/2013 2-7 Rev. 0 12/12/2013 2-8 Rev. 0 12/12/2013 2-9 Rev. 0 12/12/2013 2-10 Rev. 0 12/12/2013 2-11 Rev. 0 12/12/2013 i

Rev. 0 12/12/2013 TABLE OF CONTENTS2 SITE CHARACTERISTICS 2----2 .1 G eog raphy an d D em og raphy .......................

....... ....... ....... ....... ....... ...... 2-I12 .1 .1 S ite L o c a tio n a n d D e sc rip tio n ------. .------..------------

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_2-I- 12.1.1.1 Specification and Location 2- I2 .1.1.2 B o undary and Z o ne A rea M aps ---------------------------.................

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2-.52 .1 .1 .3 P o p u la t io n D is tr ib u t io n ...........

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2 -.52.2 N earby Industrial, Transportation, and M ilitary Facilities

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2-52.2.1 Location and Routes 2-52.2.2 Air Traffic 2-52.2.3 A nalysis of Potential A ccidents at Facilities

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2-62.3 Meteorology

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62.3.1 G eneral and Local C lim ate --- .............

...... .... 2--.62.3.1.2 Humidity

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2---62.3.1.3 Wind 2-62.3.1.4 Temperature and Precipitation-._.

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2-72.3.1.5 Severe Weather Phenomena 2-72.3.1.5.1 Tropical Storms and Hurricanes

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72.3.1.5.2 Tornadoes 2-82 .4 H y d r o lo g ic E n g in e e r in g ............................................................... ............. ..-2 -92.4.1 Flooding 2-92.5 Geology, Seismology, and Geotechnical Engineering

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-102.5.1 Regional Geology ------------------------------------------

102.5.2 Site Geology ---------------------------------------------

1I2.5.3 Surface Faulting

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2--112.5.4 Stability of Subsurface Materials and Foundations 2- 112 .5 .5 S tab ilities o f S lo p es 2-----------------------------

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.-.1 12 .6 R e fe re n c e s ----------------------------------------------------------

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2 7- 1 1LIST OF TABLES2-1 Wind Data Summary for January 1, 1980 to December 31, 2009 for the Gainesville Regional A irport (Ref. 2.4) ...........................................................

.................... 62-2 Temperature and Precipitation Data Summary for May 1, 1960 to April 30, 2012 for theG ainesville Regional A irport (Ref. 2.3) .........

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.272-3 Alachua County Tornado Events from 1950 to 2013 --------------------------------

8LIST OF FIGURES2-1 Map of the Greater Gainesville Area Showing Placement of University of Florida and MajorLandmarks 2-22-2 Map of the University of Florida Campus -----------------------------------

2-32-3 UFTR Location (Bldg. 557) on the University of Florida Campus 2-42-4 FEMA Flood Map Showing UFTR Location in Flood Zone 'X' -------..

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2-10ii Rev. 0 12/12/2013

2. SITE CHARACTERISTICS This chapter describes the site characteristics of the UFTR on the University of Florida campus including characteristics in the vicinity of the UFTR and their relation to the safety and operation of the UFTR.The conclusion reached in this chapter and throughout this document is that the selected site is well-suited forthe UFTR when considering the inherently safe design of the reactor and relatively benign consequences of theMaximum Hypothetical Accident (MHA). This is consistent with .the conclusions reached for the other non-power reactor facilities throughout the world. Many of which are located on university

campuses, in hospitals, and other highly populated areas.2.1 Geography and Demography 2.1.1 Site Location and Description The UFTR is located on the campus of the University of Florida in Gainesville, Florida.

The city of Gainesville is approximately in the center of Alachua County, which is in the north-central part of Florida, approximately midway between the Atlantic Ocean and the Gulf of Mexico. The Gulf of Mexico is about 50 miles to thesouthwest and the Atlantic Ocean is about 65 miles to east.2.1.1.1 Specification and LocationThe UFTR is located in the northeast quadrant of the main University of Florida campus approximately twomiles from the historic center of the city (University Avenue and Main Street).The UFTR location is approximately:

• 20 meters south of the Reed Laboratory;

• 40 meters west of Weimer Hall -Journalism College;* 90 meters east of Rhines Hall -Materials Sciences;

• 130 meters north of the J.W. Reitz Union; and* 190 meters east of East Hall, the closest residence hall.Figures 2.1, 2.2, and 2.3 illustrate the location of the UFTR with respect to the city of Gainesville and the UFcampus.2-1 Rev. 0 12/12/2013 Figure 2-1 Map of the Greater Gainesville Area Showing Placement of University ofFlorida and Major Landmarks 2-2 Rev. 0 12/12/2013 Figure 2-2 Map of the University of Florida Campus2-3 Rev. 0 12/12/2013 Figure 2-3 UFTR Location (Bldg. 557) on the University of Florida Campus2-4 Rev. 0 12/12/2013 2.1.1.2 Boundary and Zone Area MapsThe map indicated in Figure 2-1 shows the property boundaries of the University of Florida campus. The siteboundary lines are the same as the property lines. The locations of the principal structures in the vicinity of thereactor building are shown in Figure 2-3.The operations boundary is the reactor building and annex (designated UF Bldg. 557), including the west fencedlot as necessary.

2.1.1.3 Population Distribution Based on 2010 U.S. Census Bureau data, the city of Gainesville, Florida has a population of 171,787 with atotal population in Alachua County of 247,336 (Ref. 2.1). The University of Florida has a population (studentand employees) of approximately 65,000 people.The University of Florida houses approximately 9,500 residents in all of the student residence halls and familyhousing.

The nearest to UFTR is East Hall which is located approximately 190 meters west and has a capacityof approximately 210 residents.

East Hall is part of a series of buildings referenced as the Tolbert area capableof housing approximately 990 residents.

2.2 Nearby Industrial, Transportation and Military Facilities 2.2.1 Location and RoutesTransportation routes located close to campus are shown in Figures 2-1 through 2-3. State Roads 121, 26 and24, U.S. Highway 441 and Interstate 75 are well-traveled, major transportation routes through and/or aroundGainesville.

The primary usage of State Roads 121,26 and 24 and U.S. Highway 441 are for commuter travel tothe University of Florida and to the center of the city. Interstate 75 is used primarily for commuter travelto/from surrounding cities and for tourist travel to South and Central Florida.

Other uses for all of the aboveroads include shipment of dangerous, toxic or explosive substances; however such usage would be minimalparticularly for those roads nearest the UFTR site, i.e., State Roads 26., 121,and 24 and U.S. Highway 441.The UFTR location is approximately:

• 450 meters south of the State Road 26;* 850 meters west of U.S. Highway 441;* 1300 meters north of State Road 24; and* 2400 meters east of State Road 121.Since the reactor building is located between the Nuclear Sciences Building on the south side and the Reedlaboratory building on the north, any explosion of transported materials would first have to exert its effect onboth of these buildings.

Although not immediately

adjacent, the same protection is afforded on the east side bythe Journalism Building and on the west side by the unoccupied Chiller Unit Facility.

The location of the UFTRbuilding in relationship to all nearby buildings and the campus in general provides for shielding and a protective effect from the forces of explosion on all sides.There are no refineries, chemical plants, mining facilities, manufacturing facilities, water transportation routes,fuel storage facilities, military facilities, or rail yards located near the UFTR.2.2.2 Air TrafficThe Gainesville Regional Airport is the only airport in the vicinity.

The airport is located on the northeast edgeof Gainesville, approximately eight (8) kilometers northeast of the UFTR.2-5 Rev. 0 12/12/2013 The Gainesville Regional Airport has two runways with a total of approximately 11,660 ft. of runway length(compass headings of approximately 2400 and 2800). The airport averages approximately 190 aircraft operations per day and has approximately 119 aircraft based on it, 95 of which are single engine aircraft (Ref. 2.2).Based on the low probability of aircraft accidents, the relatively small number of operations, the size of mostaircraft

involved, the orientation of the runways, the distance between the UFTR and the airport, the relatively small areas of aircraft impact, and the protected location of the UFTR building in reference to other surrounding buildings, it is concluded that the probability for an aircraft accident affecting the UFTR facility is remote.2.2.3 Analysis of Potential Accidents at Facilities Gainesville is primarily an education-related, small-business-oriented city. The areas surrounding the UFTR siteand University of Florida campus are representative of most of Gainesville, consisting primarily of residential areas, apartment complexes and small businesses such as restaurants, retail stores, etc. A study of area activities shows that there are no significant industrial activities in this immediate area that could lead to potential accidents having an effect on the UFTR Reactor Building.

2.3 Meteorology

2.3.1 General and Local ClimateAlachua County, in the north-central part of Florida, is located approximately midway between the AtlanticOcean and the Gulf of Mexico. The average year in Alachua County may be divided into two seasons:

thewarm, rainier season and a cooler, drier season. The warm, rainier season runs from about the middle of May tothe end of September.

The cooler, drier season dominates the remainder of the year.2.3.1.2 HumidityRelative humidity is highest during morning hours and generally averages between 89-95% throughout the year.During the afternoon, humidity is generally lower with an average ranging fi'om about 55-64% during thewarmer, rainier season and 49-60% during the remainder of the year (Ref. 2.3).2.3.1.3 WindA 30-year wind rose is used to describe the average wind speed and wind direction.

This wind summary data isprovided in Table 2-1 below.Table 2-1 Wind Data Summary for January 1, 1980 to December 31, 2009 for the Gainesville RegionalAirport (Ref. 2.4)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% 3.552-6 Rev. 0 12/12/2013 SSE 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 = 2.812.3.1.4 Temperature and Precipitation Temperature and precipitation summary data is provided in Table 2-2 below.Table 2-2Temperature and Precipitation Data Summary for MayGainesville Regional Airport (Ref. 2.3)I, 1960 to April 30, 2012 for theAverage Climate SummaryMonth Maximum Temp (F) Minimum Temp (F) Total Precipitation (in)Jan 66.5 42.5 3.27Feb 69.4 45.1 3.55Mar 75.2 49.9 3.72Apr 81.1 55.1 2.22-May 87.1 62.6 2.74Jun 89.8 69.0 6.91Jul 90.7 71.4 6.63Aug 90.3 71.6 7.06Sep 87.3 69.0 5.01Oct 81.3 60.1 2.77Nov 74.4 50.8 1.87Dec 68.0 43.9 2.56Annual 80.1 57.6 48.322.3.1.5 Severe Weather Phenomena 2.3.1.5.1 Tropical Storms and Hurricanes Tropical storms and hurricanes are not considered a great hazard at the University of Florida reactor site forthree reasons.

First, the likelihood of a hurricane traversing Alachua County is very small. Second, the severityof the storm is reduced by the overland movement necessary for a storm from the Gulf of Mexico or theAtlantic Ocean to reach the Gainesville area. Third, tidal flooding is prevented by the inland location of theUFTR site and there are no significant bodies of water near the UFTR site. Experience with the passage of pasthurricanes indicates maximum gusts of approximately 60 miles per hour around the site. It should be noted thateven thunderstorms occasionally develop gusts of this severity.

2-7 Rev. 0 12/12/2013 2.3.1.5.2 Tornadoes As shown in Table 2-3, a total of forty-two tornado events have been recorded in Alachua County from 1950 to2013 (Refs. 2.4, 2.5). From this total, eight tornadoes reached a magnitude of F2 (Fujita Scale) with the lastoccurring in 1986.Table 2-3Alachua County Tornado Events from 1950 to 2013Date Fujita Scale Deaths Injuries6/8/57 F2 0 08/16/64 Fl 0 09/21/66 Fl 0 09/28/66 F2 0 012/25/69 Fl 0 02/3/70 F2 0 05/11/71 Fl 0 04/4/73 F2 0 01/25/75 FO 0 07/6/76 F1 0 06/21/77 Fl 0 04/19/78 F2 0 65/1/78 FO 0 05/4/78 F2 0 46/21/79 F l 0 05/25/80 Fl 0 07/6/80 Fl 0 010/28/80 Fl 0 03/22/81 FO 0 02/2/83 F2 0 46/21/83 Fl 0 06/30/85 Fl 0 03/14/86 F2 0 07/9/87 FO 0 08/8/90 FO 0 09/28/90 FO 0 06/13/92 FO 0 13/12/93 F1 1 410/30/93 FO 0 010/30/93 FO 0 01/3/94 FO 0 010/30/94 FO 0 04/8/95 FO 0 02/2/96 FO 0 07/20/02 FO 0 04/25/03 FO 0 04/25/03 FO 0 09/5/04 FO 0 08/3/05 FO 0 012/16/07 EFI 0 02/26/08 EFO 0 03/24/12 EFO 0 02-8 Rev. 0 12/12/2013 According to statistical methods provided by Thom (Ref. 2.6), the probability per year of a tornado striking apoint within a given area may be estimated using Equation 2-1 as follows:ZTP -Equation 0-1Awhere symbols are defined as follows:P = the mean probability per year of a tornado striking a point within area A.Z = the geometric mean tornado path area, square miles.T = the mean number of tornadoes per year in the area.A = the area of concern, square miles.The value ofT (mean number of tornadoes per year) is very conservatively taken as 1.0 per year for the 63 yearperiod (1950-2013) for Alachua County. Based on data reported by Thom (Ref. 2.6) for midwest tornadoes, an average tornado path area is about 2.82 square miles which is the applicable but conservative value used forZ. Using the value of A equivalent to the total land area of Alachua County (965 square miles) in which theUFTR site is located, a value of P = 2.92 x 10-3 /year is calculated as the mean probability per year of a tornadostriking within the UFTR site.This probability of such a tornado striking within the UFTR site (reactor building occupies less than an acre) isconservative because the mean tornado path area in Florida is less than the national average used in thecalculation.

In addition other nearby campus structures surrounding the reaclor building provide significant protection.

The mean recurrence

interval, R=I/P, of a tornado striking a point anywhere in which the site is located is,therefore, about 342 years. However, in the period from 1950 to 2013, only 25 property-damaging tornadoes have been reported in Alachua County, Florida where the site is located (also equivalent to a smaller probability of P= 1.16 x 103 /year which further emphasizes the conservatism of the P = 2.92 x 103 /year value calculated above). Though this probability is conservative and very low, tornadoes are considered to be the most likelynatural disaster to affect the UFTR site.2.4 Hydrologic Engineering 2.4.1 FloodingThere are no dams in the University of Florida -Gainesville area that could affect the reactor site in case offailure.

No major streams or rivers run near the site area which is well inland removing the potential for tidalflooding.

Because of this, and the well-drained location of the UFTR site, no special consideration is given tofloods in the UFTR design.Exhaustive studies have indicated no record of any major flood in the general UFTR site area during the past100 years. Figure 2.4 shows the FEMA flood map in effect since June 2006 illustrating that the UFTR is locatedin an area designated Zone X (areas outside the potential floodplain).

Portions of Lake Alice and theWastewater Treatment plant are shown near the bottom of Figure 2.4 in an area designated Zone A (nearestpotential floodplain

-no base flood elevations determined).

Finally, emergency flood procedures are addressed in the UFTR Standard Operating Procedures so no furtherconsideration is necessary here.2-9 Rev. 0 12/12/2013 Figure 2-4 FEMA Flood Map Showing UFTR Location in Flood Zone 'X'2.5 Geology, Seismology and Geotechnical Engineering 2.5.1 Regional GeologyThe solid bedrock in this area is porous and cavernous Ocala limestone which occurs in a broad truncated domewith its crest in Levy County southwest of Gainesville.

The Ocala formation is overlain by other porous2-10 Rev. 0 12/12/2013 limestones and semipermeable sandy clays (Hawthorne formation).

This is capped by loose surface sands.2.5.2 Site GeologyThe specific site geology is very similar to that of the region as a whole. Most of the Gainesville area and thatpart of the campus north of Radio Road, including the UFTR site, is underlain by a loamy fine-sand type of soil.This was derived from residual Hawthorne formation and is characterized by a typical slope of 2 to 7 percent,light brown or brownish grey surface soil, light yellowish brown or pale brown subsoil, nearly loose to loosewith good natural drainage.

2.5.3 Surface FaultingThere is ample evidence that Florida has been stable and free of earthquakes for about one million years, and itis considered to be one of the most stable areas in the entire United States. There have, however, been severalsmall earth tremors which have caused slight damage such as small cracks in plaster wall in some areas of thestate.2.5.4 Stability of Subsurface Materials and Foundations The limerock formations are very stable geologically as indicated by the relative absence of earth movementactivity in Florida over the past million years.2.5.5 Stability of SlopesThere are no rocks or soil slopes of concern for the UFTR site. The general downward incline toward the westand south eliminates the possibility of drainage or flooding problems.

The general site and area topography have shown that this area is very stable. There is no danger of landslides since the general slope of the land is agradual incline with no sharp contours.

2.6 References

2.1 United States Census Bureau, www.census.gov, 2010 Census.2.2 Federal Aviation Administration

-Gainesville RGNL Airport Master Record, www.gcrl

.com, January2013.2.3 The Southeast Regional Climate Center, www.sercc.com 2.4 NOAA Online Climate Data Center, www.nc.dc.no.a..gov 2.5 Tornado Project, Florida Tornados 1950-1995, www.tornadoproject.coom 2.6 Thom, H.C.S., WMO Technical Note #81, 1966.2-11 CHAPTER 7INSTRUMENTATION AND CONTROLSYSTEMS Rev. 0 12/12/2013 Chapter 7 -Valid Pagesii7-17-27-37-47-57-67-7Rev. 0Rev. 0Rev. 0Rev. 0Rev. 0Rev. 0Rev. 0Rev. 0Rev. 012/12/2013 12/12/2013 12/12/2013 12/12/2013 12/12/2013 12/12/2013 12/12/2013 12/12/2013 12/12/2013 Rev. 0 12/12/2013 TABLE OF CONTENTS7 INSTRUMENTATION AND CONTROLS7.1 Design of Instrumentation and Control Systems.....

......7 .1.1 D esig n C riteria ..................................

... ......7.1.2 Design-Basis Requirements 7.1.3 Systems Description 7.1.3.1 Reactor Power Measurements 7.1.3.1.1 Reactor Power Channel I7.1.3.1.2 Reactor Power Channel 27.1.3.2 Process and Temperature Measurements 7.1.3.2.1 Primary Coolant System7.1.3.2.2 Secondary Coolant System7.1.3.2.3 Shield Tank System ..........

7.2 R eactor C ontro l System -..---------------

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7.2.1 Control-Blade Drives7.2.2 Control-Blade Inhibits7.2.3 Automatic Controls7.3 Reactor Protection Systems7.3.1 Trip Circuits7.4 Emergency Safety Features Actuation System ..........

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7.5 Control Console and Display Instruments

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7.6 Radiation Monitoring SystemLIST OF FIGURES7-1 Operating Ranges of UFTR Nuclear Instruments 7-17-17-17-17-17-27-27-27-37-37-3------ ------ ----- ------ ----- 7-.-3... ...... ...........

--7 47-47-47-47-5--.. ......---.-------7 7 67-67-7ii Rev. 0 12/12/2013 7 INSTRUMENTATION AND CONTROLSSince the UFTR is a low power, self-limiting

reactor, the instrumentation and associated controls are considerably simplified when compared to instrumentation and control systems of large power reactors.

Many of the instrument outputs are shared between the systems.The instrumentation and control (I&C) systems of the UFTR comprise the following subsystems:

• Reactor Control System (RCS);0 Reactor Protection System (RPS);* Process Instrumentation; and* Radiation Safety Monitoring Systems.The system instruments are hardwired analog instrument type with the exception of portions of the temperature monitoring system that are of the digital system instrument type. Additionally, several data recorders have beenreplaced with digital data recorders.

7.1 Design of Instrumentation and Control SystemsTwo channels of neutron instrumentation provide the UFTR with independent, separate indication of reactor powerfrom the source level to 150% of the rated thermal power.The RCS is composed of four control-blade drive systems, two nuclear instrumentation

channels, one automatic control system, one interlock system and one monitoring system.The RPS is composed of the Control-Blade Withdrawal Inhibit System, Safety Channel 1, Safety Channel 2, andmonitored parameters.

The monitored parameters are both nuclear and non-nuclear or process variables.

7.1.1 Design CriteriaThe instrumentation and control system is designed to provide the following:

• information on the status of the reactor and reactor-related systems;0 means for manually withdrawing or inserting control rods;* automatic control of reactor power level;0 automatic scrams in response to selected abnormal operating parameters or equipment parameters, and* monitoring of radiation and airborne radioactivity levels.7.1.2 Design-Basis Requirements The primary design basis of the UFTR is the Safety Limit on fuel and cladding temperature.

The Excess Reactivity insertion accident described in FSAR Chapter 13 demonstrates that no automatic control orsafety functions are needed to prevent reaching the Safety Limit. The Limiting Control Settings specified in theTechnical Specifications are non-safety related trip set points chosen to ensure MODE I operation remains boundedby the thermal hydraulic analysis described in FSAR Chapter 4.7-1 Rev. 0 12/12/2013 7.1.3 Systems Description 7.1.3.1 Reactor Power Measurements The two channels of neutron instrumentation provide the UFTR with independent and separate monitoring of thereactor power level. Figure 7-1 shows the operating ranges of the detectors used to monitor UFTR power levels.7.1.3.1.1 Reactor Power Channel IReactor Power Channel I provides the operator with period and measured power from source level to 150% of ratedthermal power. The signals are provided from two detectors, a B-10 proportional counter and a fission chamber.The detectors are connected to circuitry containing a pre-amplifier, a log amplifier, and a linear amplifier.

Trips areprovided for over power, short period, and loss of detector high voltage.

A blade withdrawal interlock is activated for specific conditions impacting channel operability.

The period signal is obtained through a derivative circuit that produces a voltage proportional to the inverse of thereactor period. This is then amplified and displayed on a control panel meter that ranges in seconds from -30 to + 3sec. An adjustable bistable circuit activates a trip, currently set at +3 seconds.The linear amplifier accepts the linear current signal from the pre-amplifier.

The output signal is then displayed asthe power level on a linear scale ranging from I to 150% of rated power. An over power trip is set at 119% ratedpower resulting from operation of a bistable circuit.

The channel also generates test signals to check the functioning of the channel.7.1.3.1.2 Reactor Power Channel 2Reactor Power Channel 2 provides the operator with measured power from source level to 150% of rated thermalpower and can be used to maintain steady power level through an automatic flux control servo system. The signalsare provided from two detectors, a compensated ion chamber (CIC) and an uncornpensated ion chamber (UIC).Trips are provided for over power and loss of detector high voltage.

A blade withdrawal interlock is activated forspecific conditions impacting channel operability.

The CIC provides linear power level indication from just above source level to 100% of rated thermal power. TheCIC is connected to circuitry containing a pico-ammeter with a multiple position range switch resulting in indicated power as a percentage of range switch position.

The pico-ammeter sends a signal, which is a function of the linearindication of reactor power, to the servo amplifier as a part of an automatic reactor control circuit.

At the servoamplifier, the signal is compared with the signal from the servo flux control.The UIC provides power level indication from 1% to 150% of rated thermal power. The UIC is connected tocircuitry containing an operational amplifier and an adjustable bistable trip. An over power trip is set at 119% ratedpower resulting from operation of a bistable circuit.

The channel also generates test signals to check the functioning of the channel.7.1.3.2 Process and Temperature Measurements 7.1.3.2.1 Primary Coolant SystemA primary coolant flow monitor, with sensor located in the primary fill line, indicates flow and trips the reactor ifflow is below the set point.A coolant flow switch, located in the return line of the primary coolant system to the primary coolant storage tank,initiates a reactor trip in case of a loss of return flow. This flow switch actuates only after the return line has beendrained of water or flow stops.7-2 Rev. 0 12/12/2013 A sight glass, attached to the north wall of the reactor room, shows the water level in the core allowing a visualcheck of the primary coolant level. A float switch activates the reactor trip system when the water level in the core isbelow the pre-set limit.Temperature sensors are located at each of the six fuel box discharge lines to monitor water temperature from eachfuel box. Additional sensors monitor the temperature of the bulk primary water going to and exiting from the core.Temperature signal information is sent to an input module that converts the signal to a linearized voltage output.These voltage outputs are sent to a data acquisition card that commands a relay board for alarming and tripconditions.

The monitored temperatures are displayed on a temperature monitor virtual instrument (computer monitor) as well as on a paper recorder located in the reactor control room. Monitored temperature points exceeding preset levels will result in an audible alarm followed by reactor trip.A resistivity meter enables on line monitoring of resistivity of the primary.

The meter annunciates if systemresistivity drops below an adjustable preset value.To monitor water intrusion from any source into the primary equipment pit, a level switch in a small sump at thelowest point of the pit floor will activate an alarm upon collecting water at I in. above pit floor level. The primaryequipment pit sump alarm annunciates at a control unit mounted on the east wall of the control room.7.1.3.2.2 Secondary Coolant SystemA key operated switch inside the console rear door is used to switch secondary scram modes between well water (10second trip delay) or city water (immediate trip) modes of operation.

In either mode, the trip function is active onlywhen reactor power is I% or higher.In the well water mode, a reduction of flow to a pre-set limit will illuminate a yellow warning light on the right sideof the control console.

A further reduction of flow to another pre-set limit will illuminate a red scram warning lighton the right side of the console, and will illuminate a red warning light on the secondary flow scram annunciator light. Approximately ten seconds later, the trip will occur. When in the city water mode, if water flow reached thepre-set limit the reactor will trip.7.1.3.2.3 Shield Tank SystemA water level switch at the top of the reactor shield tank will trip the reactor when the water level drops below apreset value.7.2 Reactor Control System7.2.1 Control-Blade DrivesThe four control blades are positioned by control blade drives through a magnetic clutch power circuit whichcouples the blade drive shafts to the blade drive motors. Interruption of clutch current decouples the drive motorfrom the blade drive shaft allowing the blade to gravity fall to its fully inserted position.

Control blade magnetpower is controlled through the three-position key switch.Twelve backlit push button switches are arranged in the center of the control panel in three rows of four vertical sets,one set for each control blade. Each set of switches contains a white DOWN switch, a red UP switch, and a yellowON (magnet on) switch.When the white DOWN light is illuminated, the control blade drive motor power circuit is prevented from driveaction via the DOWN backlit pushbutton switch. When the red UP light is illuminated, control blades in manualcontrol are similarly prevented from up motion. The yellow ON light is series-connected in the magnetic clutchpower circuit so that if the yellow light is on. the magnetic clutch is energized; if the yellow ON light is off, themagnetic clutch is deenergized.

7-3 Rev. 0 12/12/2013 When any ON push button switch is depressed, magnet current is interrupted by actuation of the backlit switch, andthe ON light remains extinguished for as long as the switch is depressed.

If the control blade is above its down limit,the blade will gravity fall back into the core. Turning off the reactor key has the same effect. In the event of a loss ofpower, these blades fail safe, falling into the core by gravity.The positions of the control blades relative to their lower limits are indicated on individual digital blade POSITIONindicators mounted on the control panel.Limit switches in the blade drive right angle gear box send a signal to the backlit control blade switches to indicateeither full-in or full-out position.

This also inhibits the control blade drive motor from actuating when the blade is atits limits of travel.Wiper arm position indicators, mechanically coupled to the blade drive shafts via beveled gears, transmit bladeposition to the control console.7.2.2 Control-Blade InhibitsControl blade withdrawal inhibits function to prevent blade withdrawal for the following conditions:

• A source count rate of 2 cps or less;* A reactor period of 10 seconds or shorter;0 Safety Channel I and 2 and wide-range drawer Calibrate (or Safety I Trip Test) switches not in"OPERATE" or "OFF" condition.

This inhibit condition assures the monitoring of neutron levelincreases and prevents disabling protective functions; 0 Attempt to raise any two or more blades simultaneously when the reactor is in manual mode, or two ormore safety blades simultaneously when the reactor is in automatic mode. This multiple bladewithdrawal interlock is provided to limit the reactivity addition rate;Power is raised in the automatic control mode at a period shorter than 30 sec. The automatic controller action is to inhibit further regulating blade withdrawal or drive the regulating blade down until theperiod is greater (slower) than or equal to 30 seconds.7.2.3 Automatic ControlThe UFTR Automatic Control System is used to hold reactor power at a steady power level during extended reactoroperation at power and may be used to make minor power changes within the maximum range of the switch setting.While the automatic mode of reactor control is selected, the manual mode of operation is disabled; the control modeswitch must be placed back in MANUAL before the regulating blade will respond to its UP or DOWN controlswitches.

The neutron flux controller compares the linear power signal from the pico-ammeter with the powerdemand signal and moves the regulating blade to reduce any difference, thereby maintaining a steady power level.7.3 Reactor Protection System7.3.1 Trip CircuitsThe UFTR facility is provided with two types of reactor trips. These reactor trips are classified into two categories:

Full-trip, which involves the insertion of the control blades into the core and the dumping of theprimary water into the storage tank (this type of trip will dump primary water only if 2 or more controlblades are not at bottom position);

7-4 Rev. 0 12/12/2013

• Blade-trip, which involves only the insertion of the control blades into the reactor core (withoutdumping of the primary water).One of five conditions must exist for the initiation of the Full-trip; these five conditions include:* Short Period (3 seconds or less);* High Power (119%);* Reduction of high voltage to the neutron chambers of 10% or more;* Turning off the console magnet power switch;* A.C. power failure.The conditions that must exist for the initiation of a Blade-trip include:* Loss of power to Stack Dilution fan;* Loss of power to Core Vent fan/damper;

• Loss of power to the deep well pump when operating at or above I kW and using deep well forsecondary cooling;* Secondary flow below 60 gpm when operating at or above I kW using the well water system forsecondary cooling ( 10 sec delay);* Secondary flow below 8 gpm when operating at or above I kW using city water for secondary cooling(no delay after initial 10 second time interval);

• Shield tank water level 6" below established normal level;* Loss of power to primary coolant pump;* Primary coolant flow below 41 gpm (inlet flowrate);

• Loss of primary coolant flow (no return flow);* Primary coolant level below 42.5";* Any primary coolant return temperature above I 55°F;* Primary coolant inlet temperature above 99°F;* Initiation of the evacuation alarm;* Manual reactor trip button depressed.

A set of annunciator lights is used to indicate scram conditions.

7.4 Engineering Safety Features Actuation SystemThere are no engineered safety feature actuation systems.7-5 Rev. 0 12/12/2013 7.5 Control Console and Display Instruments All functions essential to the operation of the UFTR are controlled by the operator from the control console.The reactor control panel contains the following control and indicating instrumentation:

• A console power switch.* A three-position key switch.* A set of control-blade switches.

• One set of switches for controlling the secondary system city water valve.* Four control blade position digital indicators.

• A manual scram bar.* A set of scram and blade interlock annunciator lights.* Power Channel #1 meters and calibrate/test controls.

• Power Channel #1 period meter and calibrate/test controls.

• Power Channel #2 meter and test controls (UIC).* Power Channel #2 linear range switch (CIC).* Power Channel #2 recorder (CIC).* A mode selector switch for automatic or manual operation.

• A %-demand control potentiometer.

• Reactor cell door monitors.

• Reactor equipment control switches and annunciator lights.* Digital clock.* Pu-Be source alarm indicator.

• Rabbit system solenoid switch.When the console key switch is "ON", a red rotating beacon located in the reactor cell together with four "reactoron" lighted signs are energized.

The "reactor on" lights are located on the outside of the east side of the Reactorbuilding on the second floor level, on the entrance hallway leading to the control room, in the upstairs

hallway, andon the west outside reactor building wall.7.6 Radiation Monitoring SystemThe reactor vent system effluent monitor consists of a GM detector and preamplifier, which transmit a signal to thecontrol room to monitor the gamma activity of the effluent in the downstream side of the absolute filter beforedilution occurs. The stack monitoring system also consists of a log rate meter-circuit and indicator, a recorder, andan auxiliary log rate meter with an adjustable alarm setting capability.

The area radiation monitoring system consists of three independent area monitors with remote detector assemblies, interconnecting cables, recorders, and count rate meters. Each detector has an energy compensated Geiger counterwith built-in Kr-85 check source that can be operated from the control room. The signals from these detectors aresent directly to the log count rate meter and recorder.

Two levels of alarm are provided (warning and alarm). Bothlevels latch in the alarm mode to preclude false indication ifa high dose rate saturates the detector.

Any two of themonitors seeing a high radiation level will automatically actuate the building evacuation alarm. Actuation of theevacuation alarm automatically trips the reactor and the reactor cell air handler system.The stack monitor and 3 area monitor modules in the control room are equipped with test switches and green "NOFAIL" lights that go out if the modules do not receive signal pulses from the detectors.

Floating battery packs supplypower to the units in the event of electrical power loss.Air from the reactor cell is pulled through the airborne radioactivity monitor which is equipped with a recorder andan audible and visible alarm setting.7-6 Rev. 0 12/12/2013 FISSION UNCOMPENSATED CHAMBER ION CHAMBER (IT'i00--XOMPENSATED ON CHAMBER10ot-I_-ISAFETYCHANNEL II'SAFETYCHANNEL 210"1IF6Ili,1010'510 -6SI041010210210l00101is00.1'o2PROPORTIONAL COUNTER10"7 =--10IWIDERANGEMULTIRANGE LINEAR10"5EXTENDEDWIDE RANGE-I A-10-1Figure 7-1Operating Ranges of UFTR Nuclear Instruments 7-7