ML051050259
| ML051050259 | |
| Person / Time | |
|---|---|
| Site: | U.S. Geological Survey |
| Issue date: | 04/11/2005 |
| From: | Day W US Dept of Interior, Geological Survey (USGS) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC5120 | |
| Download: ML051050259 (10) | |
Text
USGS science fore changing world Department of the Interior US Geological Survey Box 25046 MS-974 Denver CO, 80225 April 11, 2005 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555 Gentlemen:
The U.S. Geological Survey is herein responding to your request for additional information (TAC No. MC5120) dated March 10, 2005. This concerns the USGS amendment request to its research reactor facility license (No. R-113, Docket 50-274) to allow the use of aluminum-clad TRIGA fuel in the core.
Correspondence concerning this response should be directed to Tim DeBey, Reactor Supervisor.
Sincerely, Warren Day Reactor Administrator I declare under penalty of perjury that the foregoing is true and correct.
kxecuted on 4/11/05 ..A. I ADOpO
REQUEST FOR ADDITIONAL INFORMATION UNITED STATES GEOLOGICAL SURVEY DOCKET NO. 50-264
- 1. Your answer to question 3 of our request for additional information (RAI) dated December 7, 2004, discussed fuel temperature in the F and G rings when limiting the measured temperature of a stainless steel clad fuel element to 8000C in the B ring. Technical Specification (US) D.3 also allows the instrumented fuel element to be placed in the C ring, where fuel temperatures could be lower than in the B ring. Limiting the measured fuel temperature to 8000 C in the C ring could result in higher temperatures in the F and G rings than would result from limiting measured temperature to 8000C in the B ring. Please provide maximum fuel temperatures in the F and G rings if the measured temperature of 8000C is taken from an instrumented fuel element in the C ring. (Note that your answer to question 9 below may change the 8000C temperature in this question.)
Response: In reference to question 9 of this document and our response, we are proposingto limit the measuredtemperature in (stainless steel) fuel elements to 7500C in the B-rng and 667 *Cin the C-ring.
The table below shows the expected measuredfuel temperaturesin the B, C, F, and G-ings under these maximum fuel temperature conditions. As shown, the F and G-ring fuel temperatureswould be 447-C and 383C, respectively. These values are below the proposed500C fuel temperaturelimit for aluminum-cladfuel elements.
C- F-B-ring ring ring F-Cooling peak B- peak C- peak ring G-ring G-medium temp ring A temp ring A temp AT peak ring A Description temp C C T CC) C T}°). tempC TIC)
S.S.-
Temp limit conditions 60 750 690 667 607 447 387 383 323
- 2. The instrumented fuel element contains multiple thermocouples at different locations in the fuel element. Because of this, the temperature reading from the element may not be the true maximum temperature of the fuel in the element. Discuss the accuracy of your measured temperatures as compared to true temperature and the impact this has on the various temperatures given in your RAI request responses.
Response: There are several inaccuraciesthat can occur in the fuel temperaturemeasurement One is electronics errorfrom the temperaturemeasuringinstrument, an Action PakAP4350-0003 thermocouple transmitter(see attacheddata sheet). This instrumenthas an accuracy of +0.25% of span with a cold junction compensation errorof + 1C. The result would be an erorof +4.8Cat 750-C.
The other erroroccursfrom the thermocouple not being at the actuallocation of peak temperaturein the fuel element. For steady state operations, this errorisfrom verticalmispositioningand it is approximately 10*C. Duringpulsing operationsthis erris25% ofthe measuredtemperature. The errorduringpulsing is largerbecause it is a radialpositioning erorduring the rapid transient:i.e., the peak temperature occurs nearthe fuel cladding and not at the element centerline. Forexample, duringpulsing operations an indicatedtemperature of 400"C would equal an actualpeak temperaturein the fuel element of 500-C.
This informationis taken from Figure 111-21 of the University of Illinois SafetyAnalysis Report, dated 1969.
This figure is attached.
This potentialinaccuracyimpacts our response as follows: Forsteady state operations, it should be assumed that the peak fuel temperatureis really 15C higherthan indicated. Since none of the allowed I
steady state operations show that the F or G-ring temperatures are within 15*C of the 500C proposed limit (see Table in Question I response above), there is no impact to the operational safety.
During pulsing operations, the expected measured fuel temperature in the F-rng from a $3.00 pulse is 233*C. Applying the expected error of 25% plus 5C instrument error gives a true peak fuel temperature of 296@C, much less than the 500-C proposed limit. The G-ring temperature would be less, at 252VC true peak temperature (see table below). Therefore the impact of these errors on the temperatures in our previous answers is that the temperatures are still well below the safety system limit of 5000C and there is no impact to the operational safety of the GS7R.
B-ring Cooling peak B- C-ring C- F-ring F- G-nng G-medium temp ring A peak ring AT peak ring AT peak ring AT Description temp C C T C) temp C LC)temp C CC) temp C CC)
Nominal $3 pulse -
measured temp 20 400 380 354 334 233 213 198 178 Nominal $3 pulse -peak calculated temp 20 500 480 442 422 296 271 252 227
- 3. What was the wt% of the fuel in the instrumented fuel element used to measure the fuel temperatures given in your responses to our RAI? If the fuel wt% of the instrumented fuel element is different than the fuel wt% of the aluminum clad fuel, explain what effect the difference in fuel wt% has on the conclusions presented in your RAI response.
Response: The instrumented fuel element used to measure the fuel temperatures in the RAI responses was a 8.5 wt%, stainless-steel clad element with a 15Flong fuel section. The aluminum-clad fuel elements are 8.0 wt% with 14"long fuel sections. This gives the aluminum-clad fuel elements -12.2%
less uranium loading than the instrumented fuel element that was used to measure the fuel temperatures.
The effect would be that the aluminum-clad fuel would generate less power per element and therefore the temperatures would be lowerthan calculated. This makes our RAI response conservative.
- 4. Your answer to question 3 of our RAI contains fuel temperature data based on a coolant temperature of 50"C. However, your TSs allow a bulk pool temperature up to 600C. Please present the data on fuel temperature assuming a coolant temperature of 600C.
Response: The fueltemperatures were recalculated for the condition of the coolant temperature of 600 C and the results are given below. The net result is that the F and G-ring fuel temperatures increase by 5 0C.
lCooling l F-ring F- 1 Description of GSTR medium B-ring peak B-Ipeak ring AT G-ring peak ring A7 operation. temp 0C temp 0C ring AT(rC) temp C fC temp C CC)
Normal I MWops 21 344 323 202 181 172 151
-ring at 800C 60 800 740 475 415 406 346 2
- 5. Your original application contained a table with a set of temperature measurements. For the 1 MW steady state measurement take in March of 2002, where was the instrumented fuel element located in the core.
Response: The March, 2002 fuel measurement supplied in the original application was taken in an instrumented element located in the C-rng (location C-5) of the GSTR.
- 6. Discuss the maximum fuel temperatures in the aluminum clad fuel at the reactor high power setpoint of 1.1 MW.
Response: If the GSTR was operated at 1.1 MW with the pool water temperature at 60"C, the measured fuel temperatures would be as shown in the table below. Also shown, for reference, are measured fuel temperatures at normal 1.0 MW operation.
B-ring Cooling peak B- C-ring C- F-ring F- G-ring G-medium temp ring AT peak ring AT peak ring AT peak ring AT Description temp C C )
fC) temp C temp C CC) temp C (C)
Normal I MWops 21 344 323 305 284 202 181 172 151 Max. 1.
MWops 60 415 355 373 313 259 199 226 16 These data show that fuel temperatures in the F and G-rings are well below the proposed 5000C limit for aluminum-clad fuel. If an instrument/ocation error of 15"C for steady state operations is applied to the calculated values for 1.1 MWoperations, the F and G-ring peak temperatures are 274"C and 2410C, respectively.
- 7. Your answer to our RAI question 10 was based on a coolant temperature of 500 C. However, your TSs allow a bulk pool temperature up to 600 C. Please present the data on fuel temperature assuming a coolant temperature of 60 0C.
Response: This question is identical to question 4. See question 4 for our response.
- 8. You have proposed changes to TS D.7. It appears that your proposed wording would remove the flexibility to have a core with less than 100 fuel elements operate with a power level greater than 100 kW.
Please provide a justification for your proposed change to the TS.
Response: A historical look at the fueling of the GSTR shows that the initial fuel loading for full power operations in 1969 contained 78 fuel elements. By January 1975, the core loading had reached 101 fuel elements and it has not gone below 100 fuel elements for the last 31 years. No future requirement is seen foroperation ofthe GSTR at >100 kWwith <100 fuel elements in the core. In fact, having a small core is detrimental to the neutron flux in several of our irradiation facilities. The requirement for 100 elements or more helps to reduce the power produced by each fuel element in the core, thus limiting the peak fuel temperatures and giving a safer operation.
3
- 9. TS D.3. contains a fuel temperature limit of 800*C for fuel temperature. However, General Atomics in report E-117-833, 'The U-ZrHx Alloy: Its Properties and Use in TRIGA Fuel," discusses a steady-state operational fuel temperature design limit of 7500 C based on consideration of irradiation- and fission-product-induced fuel growth and deformation. Please discuss.
Response: The operating history of the GSTR has been such that the existing limit of 800fC hasnot presenteda safety threat;however, the reduction of this limit to 75(°C would be prudent and would not affect the GSTR operations. The maximum fuel temperaturewould occurin a B-ring element, nearest the centerof the core. Because of the GSTR Technical Specification allowance for measuring fuel temperature in eitherthe B or C ring, we are herein proposingdiffering maximum indicatedfuel temperaturelimits for the two locations. The C-ing fueltemperaturelimit wouldneedto be lower than 75d'C in orderto assure that the maximum fuel temperature(B-ring) would not exceed 7500C.
The nominal powerproductionin a C-ing element is 886 of the nominalpower producedin a B-ring fuel element. Assuming a pool watertemperature of 6(PC, a maximum fuel temperature of 75(PC in a B-ing element would correspondto a maximum fuel temperatureof 6670 C in a C-ringelement. (see table below)
C- F-B-ring nng ring F- G-ring Cooling peak B- peak C- peak ring peak G-medium temp ring A temp ring A temp AT ( temp ring A Description temp C C T (CC) C T CC) C T CC)
Temp limit conditions 60 750 690 667 607 447 387 383 323 As a result of this information, it is proposedto make the following revision to Technical Specification D.3: to limit the measuredfuel temperatureto 750 0C for B-ring measurements and 667 0C for C-ring measurements. The proposedchange is given below. This proposedchangesupercedes the proposed change to D.3 in ourFebruarysubmittal. We propose to not specify a limit on the aluminum-clad fuel in the F and G rings for two reasons: (1) the limits being imposed upon the B and C-rngfuel temperatureswill inherentlyprotectthe Fand G ring fuel elements from exceeding 500 C, and (2) no instrumentedaluminum-clad fuel elements are available to provide the associatedmeasurements. The necessarycalculationsto supportthe safety of the aluminum-clad fuel elements in the F and G ringshave been provided in the documents supporting the license amendment request.
Current wording:
D.3. Fuel temperatures near the core midplane in either the B or C ring of elements shall be continuously recorded during the pulse mode of operation using a standard thermocouple fuel element. The thermocouple element shall be of 12 wt' uranium loading if any 12 wt* loaded elements exist in the core. The reactor shall not be operated in a manner which would cause the measured fuel temperature to exceed 800 6c.
Proposed wording:
D.3. Fuel temperatures near the core midplane in either the B or C ring of elements shall be continuously recorded during the pulse mode of operation using a standard thermocouple fuel element. The thermocouple element shall be of 12 wtl uranium loading if any 12 wt* loaded elements exist in the core. The reactor shall not be operated in a manner which would cause the measured fuel temperature to exceed 7500 C in a stainless steel clad element in the B ring or 667'C in a stainless steel clad element in the C ring.
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- 1.0 2.0 3.0 4,0 5.0 6.0 TEMPERATURE Vs. REACTIVITY INSERTION
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-**FIGURE , 11- 21 9
- XAction Pak AP4350 Isolated Thermocouple ACTION INSTRUMENTS Transmitter
- Isolates, Linearizes and Transmits
- Plug-in Input-Ranging Modules for Type J,K,T,E,R,S,B
- 1000 Volt Isolation
- Wide-Ranging Input and Output Adjustments
- Switch-Selectable Voltage/Current Outpul Ranges
- Three-Year Warranty The Action Pak AP4350 transmitter combines Also set S4-2 depending on whether the minimum niany useful features in one rugged, reliable input value is greater than zero degrees, or positive package. The AP4350 will accept a thermocouple (S4-2 on), or negative (S4-2 off).
input directly, and linearize, isolate, and transmit the Now calculate gain and offset from the following equivalent temperature reading for data acquisition, formulas:
Indication, or control. TS Using plug-in modules, the AP4350 can be easily GAIN = 100% x 10x (TH-TL) reconfigured In the field for any popular thermo-couple type (J, K, 7, E, R, S, B). Additionally, wide-ranging adjustments allow for virtually any OFFSET = 100% x Tj input range to be accommodated. Furthermore, the output is field-selectable for a variety of ranges, both for DC voltage and current. Where TS = effective span from Input Range Table Input signal conditioning includes cold-junction TH = high temperature, corresponding to compensation and linearization for the thermocouple maximum output input signal. Also, the input is isolated from the TL = low temperature, corresponding to output up to 1000VDC or peak AC. The AP4350 minimum output.
combines a high-performance signal conditioner, Next set percentage offset and gain on S2 and Si, linearizer, and isolator in a cost-effective, easy-to-. respectively, using the table below. (Note that use solution for Industrial measurement and control. switches are turned OFF to enable that percentage.)
CALIBRATION The AP4350 Thermocouple Transmitter can be set POSITION l l2 3 4 l5 l6 7 8 for a wide variety of outputs, and the input can be OFFADDS 1 l 4 l810 l adjusted for any span within the selected thermo-couple range down to 10% of the range. Switch SI (offset) or S2 (gain)
Ranging modules may be changed by removing the case with four screws on the bottom. The four All switches off = 165%
circuit boards can be removed from each other (see All switches on = 0%
photo), and the range module'is plugged into the input board. Adjust zero and span potentiometers to set output To set up and calibrate the AP4350, remove the top minimum and maximum with desired Inputs TL and cover. First set up the output range desired using the TH. It may be necessary to adjust the percentage up settings In the Switch Selection Table. Next select or down 1% or 2% to get exact calibration.
whether calculations will be in degrees F or C, and NOTE: Be sure to use the correct thermocouple set S4-1 accordingly (S4-1 on for 0C, off for IF). wire and a compensated thermocouple simulator or 721-0330B
1.
calibrator, or other known thermocouple source to S2 = 20% + 2% + 1% = S2-6, S2-2, S2-1 off, N "I calibrate the AP4350. all others on EXAMPLE 1: We want our Type J thermocouple Input to range from 450° F to 1100° F,with a OFFSET = 100% x -5° = -13% .1 corresponding output of OV to + 10V. With the proper Type J module installed (dash 0001), we set S5-1 on S1 = 8% + 4% + 1% = S2-4, S2-3, S2-1 off, and S5-2 off (voltage), and S3-1, 4 & 6 off with S4-2, all others on 3 & 5 on (Switch Selection Table). Since we are calculating in degrees F and our offset is positive I (4500 F), we set S4-1 off and S4-2 on.
Next we calculate gain and offset:
TS 1440 INPUT RANGE TABLE GAIN = 100% x lxT -TL 100% ~lX (1040 Dash TC IAAn tAn Nuimber Tvnn TS Input Range
- - iPt x0I AF % - 8000 - t 7---------
5000 I 1ux6bu bbuu *- AP4350-0001 J 800° C 1440° F - 80FC to+ 7500 C
-110° F to +1320°1 F We set S2-6 off and S2-2 off with the rest of S2 -0002 J 4000C 720° F -150° C to +399.9° C positions on (20% + 2% = 22%) -235° F to +399.90 F
-0003 K 12000C 2160°F -140°C to +1370 0 C OFFSET =TL 100% x = 31%
-45 -220e F to +25000 F
-0004 K 400°C 7200 F -1000C to +399.9° C We set S1-6 off, S1-5 off and S1-1 off with the -150°F to +399.9°F remainder of S1 positions on (20% + 10% + 1%= -0005 E 8000C 14400 F 00 to +8000C 31%). We adjust zero and span so that with our +32°F to +14500 F 45 0 0 F input the output is OV, and with 11000 F input -0006 T 4000C 720° F - 800C to +399.9° C the output is 10V. -1 IO" F to i 399.9° F
-0007 R 160000 2880DF +3000C to +1760°C EXAMPLE 2: Output 4-2OmA, input Type T,-500C +550° F to +32000 F to + 1250 C (dash 0006) S5-1 off S5-2 on (current) -0008 S 16000C 28800 F +300°C to +17600 C S3-6 off with S3-1 through S3-5 on (4-2OmA). S4-1 . +550° F to +32000 F on (degrees C) and S4-2 off (negative offset). -0009 B 16000C 28800F +4000C to +18200C
, +750' F to +33000 F
-GI
=10%x 400 .=0 X400 GAIN = 100% x 1Ox (125-50) = 100% x lOX 175 Switch select for degrees F.
100% x 4400 = 23%
SWITCH SELECTION TABLE Mode. S5 1 2 3 4 5 6 1 2 2-10V ON ON ON ON ON OFF Voltage 1-5V ON ON ON ONF OFF ON 0-10V OFF. ON ON OFF ON OFF 0-5V OFF ON OFF ON OFF ON O-2V OFF.- ON .ON OFF ON ON 0-1V OFF ON OFF ON ON ON 4-2OmA ON ON ON ON ON OFF 2-10mA ON ON ON ON OFF ON Current 1-5 mA ON ON ON OFF ON ON 0-2OmA. OFF ON ON OFF ON OFF. OFF ON 0-10mA OFF ON OFF ON. OFF ON 0-5 mA OFF OFF ON OFF ON ON
- 0-1 mA OFF OFF ON ON . ON ON 0-l1mA may program but not recommended
CONFIGURATION SWITCH LOCATIONS Fine Span Fine Zero Adjust Adjust PF togammabl; T ioaing Iransmlc 0anoo o Current Switch Output Range ON co en Switches 1 fF . p" s2
, i Offset Polarity
,a ;7l And F/C Switch Coarse Zero (Offset) Switch ~
- --- Coarse Span (Gain) Switch MAJOR COMPONENT SUBASSEMBLIES Base Assembly Plug-In Thermocouple Range Module Input Board Case Switch Board Output Top board Cover
1.
DIMENSIONS MOUNTING HARDWARE k..
00a APS-8 I
(22 SLOTS 1355 I
107 (4.21) Dinernions in miinwtmn 117 inches)
(4.61)
I ___ _, __ _ = r ts.110 (32) TERiMINAL SCREW i
-290 e 03 s cm ) -yp.
2',
iF ~~ ~ iCHANNiEL TRACK C1 )1 50mm Length)
'730 D ennsionsin millimtose(Inch'")
(292 Ho 4-Dose BreckeSA nuiIbIe.
SPECIFICATIONS Stability Inputs Zero: +/- (0.02%/aC plus 2.pV/ 0 C).
Span: t 0.01%/"C.
Wide-ranging inputs and outputs, field-selectable CJC Error via top accessed DIP switches and potentiometers. i 1"C, typical.
Ten to one adjustability/turn down range. Plug in Conversion Time modules for thermocouple Input types J,K,TE,R,S,B. 50OmSec.
Outputs Common Mode Rejection Field-rangeable: 0-10V, 2-10V, 0-5V, 1-5V, 0-1V, 120dB, DC-6OHz.
4-2OmA, 0-1GmA. Power Voltage Outputs: 10mA drive capability. 110V + 15% AC; 5GHz -400Hz. 4W Max.
Current Outputs: 10V compliance capability. Environmental Accuracy 00C to +60C C.
- 0.25% of span. Isolation Noise and Ripple Input to output, or either Input or output to 0.1% of span, rms. power line: 1000V DC or peak AC.
Response Time Burnout 200mSec typical. Open thermocouple detect: goes to minus overrange.
ORDERING INFORMATION How To Order Model No. Description Specify AP4350-OOOX according to the 4-digit dash AP4350-OOOX Transmitter with ranging module number from the Input Range Table. To order (see table). modules separately, specify V042 and the desired V042-OOOX Extra ranging module (see table) to 4-digit dash number V042-OOOX.
change transmitter range. Ranging modules may be ordered separately (ranging module required for operation).
Action Instruments, Inc. Action Instruments Europe, Inc.
8601 Aero Drive St. James Works San Diego, CA 92123 USA St. Pancras. Chichester TWX: 910-335-2030 (619) 279-5726 P0194NN, West Sussex, England Data Sheet 721-0330B TLX: 869331 ACTION G Printed In USA May 1986 Telephone: (0243) 774022 ACTION INSTRUMENTS