ML20154D797
| ML20154D797 | |
| Person / Time | |
|---|---|
| Site: | 05000157 |
| Issue date: | 05/13/1988 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20154D793 | List: |
| References | |
| R-080-A-009, R-80-A-9, NUDOCS 8805190349 | |
| Download: ML20154D797 (15) | |
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i CORNELL UNIVERSITY DOCKET NO. 50-157 I AMENDMENT TO FACILITY OPERATING LICENSE
! Amendment No. 9 i License No. R-80
- 1. The Nuclear Regulatory Comission (the Comission) has found that: '
A. The application for amendment to Facility Operating License No. ,
R-80 filed by the Cornell University (the licensee), dated Hay 4, 1988, as supplemented by telecon of May 5, 1988, complies with the standards and requirements of the Atenic Energy Act of 1954, as arnended (the Act), and the Commission's regulations as set i
forth in 10 CFR Chapter I; I B. The facility will o>erate in conformity with the aps11 cation, j the provisions of tie Act, and the regulations of tie Comission; J
C. There is reasonable assurance: (i) that the activities authorized 4
by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be ;
conducted in cer.pliance with the Comission's regulations set forth ;
in 10 CFR Chapter I; ;
I D. The issuance of this amendment will not be inimical to the common .
defense and security or to the health and safety of the public; !
l E. The issuance of this aner tent is in accordance with 10 CFR Part 51
{ of the Comission's regulations and all applicable requirements have i been satisfied; and i F. Publication of notice of U.is amer'dment is not required since it does :
not involve a significant hazards consideration nor amendment of a l 3
license of the type described in 10 CFR Section 2.106(a)(2). !
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- 2. Accordingly, the license is amended by changes to the Technical Soecifications as indicated in the enclosure to this license amendment, and paragraph 2.C.2. of Facility Operating License ,
No. R-80 is hereby amended to read as follows:
- 2. Technical Specifications 1 The Technical Specifications contained in Appendix A, as revised through Amendment No. 9, are hereby incor; orated in the license.
The licensee shall operate the facilit3 in accordance with the Technical Specifications.
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- 3. This license amendment is effective as of the date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
'I L d < 3di u .r.. u a ubenstein, Acting Director
- Lester S.' ,
Standardization and Non-Power ;
Reactor Project Directorate Division of Reactor Projects !!!, !Y, l Y and Special Projects Office of Nuclear Reactor Regulation j
Enclosure:
j Appendix A Technical Specifications Changes
) Date of Issuance: May 13, 1988 i
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3 ENCLOSURE TO LICENSE AMENDMENT NO. 9 j FACILITY OPERATING LICENSE NO. R-80 l I DOCKET NO. 50-157 i
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l Replace the fo11 ewing pages of the Appendix A Technical Specifications with the enclosed pages. The revised pages are identified by Amendment number and contain vertical lines indicating the area of changes. j Remove Pages Insert Pages I
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Measuring Channel: A measuring channel is the combination of sensor, lines, amplifiers, and output devices that are connected for the purpose of measuring l
the value of a process variable. ,
I Movable Experiment: A movable experinent is one that may be moved in or near i
UIe core or into and out of the reactor while the reactor is operating.
Nonsecured Experiment: Nonsecured experiments are those that should not move while the reactor is operating, but are held in place with less restraint than J a secured experiment.
Normal Mode Operation: Normal mode operation is operation with a stainless-steel-clad high-hydride thermocouple fuel element in the core.
- Operable A system or component is operable when it is capable of performing its intended function in a normal manner.
Operating: A system or component is operating when it is performing its intended function in a normal manner.
Pulse Mode: The reactor is in the pulse mode when the reactor mode selection l
- switch is in the pulse position. In this mode, reactor power is increased on j periods less than 1 see by motion of the transient control rod.
J Reactor Safety System: The reactor safety systen is that combination of
, measuring channels and associated circuitry that is designed to initiate reactor scram or that provides information that requires manual protective i action to be initiated.
Reactor Secured: The reactor is secured when all of the following conditions <
are satisfied:
1 (1) reactor shutdown l
(2) electrical power to the control rod circuits is switched off and the switch key is in proper custody j (3) no work is in progress involving incore components, experiments, or j installed control rod drives
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) Reactor Shutdown 1 The reactor is in a shutdown (suberitical) condition when I the negative reactivity of the cold, clean core is equal to or greater than the shutdown margin.
1 Reportable Occurrences: A reportable occurrence is any of the conditions 4 described in Section 6.9 of these specifications. j i
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- Research Reactor: A research reactor is one primarily designed to supply !
neutrons or ionizing radiation for experirental purposes,
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Restricted Mode Operation: Restricted mode operation is operation with one :
aluminum-clad low-hydritte thermocou)1e fuel element in the B-ring and no stainless-steel-clad high-hydride tiermocouple fuel element in the core, 1
Ring: A ring is one of the fine concentric bands of fuel elements surrounding the central opening of the core. The rings are designated by the letters B i through F, with the letter B used to designate the innermost ring.
Safety Channel: A safety channel is a measuring channel in the reactor safety system.
Secured Experiment: A secured experiment is an experiment held firmly in place by a mechanical device or by gravity providing that the weight of the .
I experiment is such that it cannot be moved by a force of less than 60 lb.
Secured Experiment With Movable Parts: A secured experiment with movable l parts is one that contains parts that are intended to be moved while the reactor is operating.
Shutdown Margin: _ The shutdown margin is the minimum shutdown reactivity necessary to provide confidence that the reactor can be made suberitical by i i means of the control and safety systens, starting from any permissible operating condition, and that the reactor will remain suberitical, without further operator action, j Standard Thermocouple Fuel Element: A standard thermocouple fuel element is a >
standara fuel element containing three sheathed thermocouples imbedded in the fuel element.
Steady-State Mode: The reactor is in the steady-state mode when the reactor mode selection switch is in either the manual or automatic position.
True Value: The true value of a parameter is its exact vaiue at any instant.
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2.0 SAFETY LIMITS AND LIMITING SAFETY SYSTEM SETTINGS f
2.1 Safety Limit - Fuel Element Temperature s
Applicability:_ This specification applies to the fuel element temperature.
Objective: The objective is to define the maximum fuel element temperature that can be permitted with confidence that no fuel element cladding damage will result.
Specification: The temperature in a stainless-steel-clad, high-hydride fuel element shall not exceed 1,000'C under any conditions of operation. The J temperature in an aluminum-clad low hydride fuel element shall not exceed 530'C under any conditions of operation Bases: The important process variable for a TRIGA reactor is the fuel element temperature. This parameter is well suited as a single specification, and it is readily measured. A loss in the integrity of the fuel element cladding t could arise from an excessive buildup of pressure between the fuel moderator i
and the cladding. The pressure is caused by the presence of fission product gases and dissociation of the hydrogen and zirconium in the fuel moderator.
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The magnitude of this pressure is determined by the fuel moderator temperature.
i fuel elements is based on data The safety limit for the high-hydride (Zrhpresented in the "Hazards Roport for th ,
MARK !! Reactor," General Atomic Report GA-6499, June 1965, first paragraph l of Section 4.7, which indicates that the stress ir, the cladding (resulting i i from the hydrogen pressure from the dissociation of the zire; onium hydride) will remain below the rupture stress provided the temperature of the fuel does i not exceed 1,000'C. ;
The temperature at which phase transitions that may lead to clat ding failure in aluminum-clad low-hydride fuel elements is reported to be 53f'C;
- references
- "Technical Foundations of TRIGA " GA-471 (1958). pp. 93-72; also in "Hazards Analysis for the Oregon State University 250 kW TRIGA Mark II Reactor," ,
j (June 1965), secticn 4.7. There is also extensive operating experience with t aluminum-clad low-hydride fuel; for example, with the Michigan State University TRIGA, which was licensed from 1974 to 1984 to operate with a mixed core of stainless-steel-clad high-hydride and aluminum-clad low-hydride elements at 250 kW and up to 25 pulses.
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! 2.2 Limitino Safety Systen Settings
) Applicability: This specification applies to the trip setting for the
! fuel element temperature channel, f 1 Objective: The objective is to prevent the safety limit from being exceeded. l l
Specifications: For a core composed of stainless-steel-cled, high-hydride ;
i fuel tiements, limiting safety system settings apply according to the location J of the standard thereccouple fuel element as indicated in the following table: l 1 !
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1 Location Limiting Safety System Settings B-ring 600'C C-ring 555'C D-rirg 480'C E-ring 380*C For a core containing an aluminum-clad low-hydride thermocouple fuel element (i.e., for restricted mode operation) the limiting safety system setting for that element shall be 230*C with the element located in the B-ring.
Bases:_ For stainless-steel-clad, high-hydride fuel elements, the limiting safety system settings represent values of the temperature, which if exceeded, shall cause the reactor safety system to initiate a reactor scran. Because the fuel element temperature is measured in a single fuel element designed for this purpose, the limiting settings are given for different locations of that element in the core. It is assumed that the maxim;o fuel temperature is produced in the B-ring.
For the stainless-steel-clad, high-hydride fuel elements, the margin betweer the safety limit of 1,000*C and the limiting safety system setting of 600*C in the B-ring was selected to assure that conditions would not arise which would allow the fuel element temperature to f: oach the safety limit. The safety margin of 400*C allows for differences ,etween the measured peak temperature and calculated peak temperature encountered in pulse operation of TRIGA reactors and for uncertainty in tem 3erature channel calibration. During steady-state operations, the equili)rium temperature is determined by the power level, the physical dimensions and proaerties of the fuel elements, and the parameters of the coolant. Because of t1e interrelation 3 hip of the fuel moderator temperature, the power level, and changes in reactivity required to increase or maintain a given power level, any unwarranted increase in the power level would result in a relatively slow increase in the fuel moderator temperature. The margin between the maximum setting and safety limit would ensure the reactor being shut down before conditions could result that might damage the fuel elements.
For the aluminum-clad, low-hydride element the margin of 300*C between the safety limit of 530'C and the limiting safety system setting of 230*C in the B-ring was selected to assure that conditions would not arise which would allow the fuel element temperature to approach the safety limit. The margin is large enough to allow for differences in properties of all aluminum-clad, all stainless-steel-clad, and mixed cores and for uncertainty in temperature channel calibration. l i
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3.0 LIMITING CONDITIONS FOR OPERATION 3.1 Reactivity Appilcability: These specifications apply to the reactivity condition of the reactor, and to the reactivity worths of control rods and experiments, and to both modes of reactor operation. Reactivity limits on experiments are specified in Section 3.8.
Ob;ectives: The objectives are to ensure that the reactor can be shut down at ar times and to ensure that the fuel temperature safety limit will not be exceeded.
Specification: The reactor shall not be operated unless the following conditions exist:
(1) The reactor is suberitical by more than 0.50$ when in the cold, xenon-freo condition, and (a) the highest worth control rod is fully withdrawn, (b) the highest worth nonsecured experiment is in its most positive reactive state, and (c) secured experiments with movable parts are each in their most reactive state.
(2) The reactivity with all control rods fully withdrawn is known to be less than 4.00$ when the reactor is cold and xenon-free and no experiments that affect reactivity are in place.
(3) When operating ir. restricted mode operation, the reactivity with all control rods fully withdrawn is less than 2.00$ with or without experiments in place.
Bases: The shutdown margin required by Specification 3.1(1) is necessary so that the reactor can be shut down from any operating condition and remain shut down after cooldown and xenon decay, even if one control rod (including the transient control rod) should remain in the fully withdrawn position.
The values chosen are intended to limit the fuel temperature to41,000*C for the stainless-steel-clad fuel in the event of inadvertent or accidental pulsing of the reactor.
The value chosen for (3) is intended to 1 Mit the temperature of the aluminum-clad element to4 530'C in the event of inedvertent or accidental pulsing of the reactor.
3.2 Steady-State Operation Applicability: This specification applies to operation of the reactor at high steady-stete power levels.
Objectives: The objectives are to prevent the fuel temperature safety limit from being exceeded during steady-state operations and to prevent inadvertent pulse operation of the reactor while it is at a high steady-state power level.
lunendment No. 9 6
Specifications:
(1) The reactor shall not be operated in the steady-state mode at power levels above 500 kW. When operating in restricted mode operation, the reactor shall not be operated at steady-state power levels above 200 kW.
(2) The reactor shall not be operated in the steady-state mode at power levels above 10 kW unless, in addition to the conditions of Section 3.1, the transient rod is fully withdrawn.
Bases: The Cornell TRIGA Hazards Analysis (Supplement 1, 1980) is based an power levels up to 500 kW.
At power levels of 10 kW or below, the steady-state fuel temperature is small compared to the temperature rise caused by a pulse of 3.00$ or less.
When our test program for initial operation above 100 kW power was conducted in February-March 1984 thermocouple measurements showed that at 200 kW the B-ring fuel temperature for the ali stainless-steel-clad high-hydride core was 160C . Even when allowing for differences resulting from the substitution of an aluminum-clad low-hydride element, the fuel temperature at 200 kW will be far below the safety limit of 530'C.
3.3 Pulse Operation Applicability: These specifications apply to operation of the reactor in the pulse mode.
Objective: The objective is to prevent the fuel temperature safety limit from being exceeded during pulse mode operation.
Specifications: The reactor shall not be operated in the pulse mode unless, in addition to the requirements of Section 3.1, the following conditions exist:
(1) The transient rod is set such that the reactivity insertion upon its withdrawal is equal to or less than 3.00$.
(2) The steady-state power level of the reactor is not greater than 10 kW.
(3) When operating in restricted mode operation, the reactor shall not be operated in pulse mode. The pulse mode circuit shall be disconnected to assure that pulsing is not possible with the key-operated switch.
Bases: These reactivity values limit the fuel temperature to (1,000'C. Speci-ficaiton 3.3(2) is intended to prohibit pulsing frem a high steady-state power level so that the final peak temperature might exceed the safety limit. Pulse mode operation could result in temperature in the aluminum-clad low-hydride element that exceed the limiting safety system setting of 230*C.
3.4 Measuring Channels Applicability: This specification applies to the reactor measuring channels.
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- l. Objective: The objective is to require that sufficient information is l
available to the operator to ensure safe operation of the reactor. i Specifications: The reactor shall not be operated unless the following conditions are met:
(1) The measuring channels described in the following table are operable and the information is displayed in the control room.
Minimum Number Required Measuring Channel Operable Operating Mode l Fuel element temperature 1 Both modes ,
Reactor power level 2 Steady state :
Reactor power level 1 Pulse mode ;
Startup count rate 1 During reactor startup Area radiation monitors 2 Both modes '
Continous air radiation monitor
- 1 Both modes Exhaust plenum radiation monitor
- 1 Both modes (2) The neutron count rate on the startup channel is greater than 1 count.
Bases: The fuel temperature displayed at the console gives continuous information on the process variable, which has a specified safety limit.
The neutron detectors ensure that measurements of the reactor power level are adequately covered.
The radiation monitors provide information to operating personnel of any impending or existing danger from radiation so that there will be sufficient time to evacuate the facility and take the necessary steps to prevent the spread of radioactivity to the surrounding environment.
The specification on the startup channel count rate is intended to ensure that sufficient neutrons are available in the core to provide a signal at the output of the startup channel during approaches to criticality.
3.5 Safety Channels and Control Rod Drop Ti_me A>plicability: This specification applies to the reactor safety system clannels and to rod drop times.
Objectives: The objectives are to require the minimum number of reactor safety system channels that must be operable in order to ensure that the fuel temperature safety limit is not exceeded, and to ensure prompt shutdown in the event of a scram signal.
Specifications: The reactor shall not be operated unless the following conditions are met.
- In lieu of information display, high-level alarms audible in the control room may be used.
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(1) The safety system channels described in the following table are operable:
Minimum Safety System Channel Number Required or Interlock Operable Function Operating Mode Fuel element temperature 1 Scram Both modes Reactor power level 2 Scram Steady-state mode Manual button 1 Scram Both modes Startup count rate interlock 1 Prevent control Reactor startup rod withdrawal when neutron count rate is less than 1/see Standard control rod position interlock 1 Prevent withdrawal Steady-state mode of the transient rod when either the safety or shim con-rol rods are not fully inserted (2) The drop time of a standard control rod from the fully withdrawn position of 90% of full reactivity insertion is less than 1 sec.
(3) When operating in restricted mode operation, one reactor power level scram trip point shall be set at 200 kW.
Bases: The fuel temperature scram provides the protection to ensure that if a condition results in which the limiting safety system setting is exceeded, an immediate shutdown will occur to keep the fuel temperature below the safety limit. The power level scram is provided as added protection against abnormally high fuel temperature and to ensure that reactor operation stays within the licensed limits. The manual scram allows the operator to shut down the system if an unsafe or abnormal condition occurs. The interlock to prevent startup of the reactor with less than 1 count /sec indicated on the startup channel ensures that sufficient neutrons are available to ensure proper startup of the reactor. The control rod position interlock will prevent the withdrawal of the transient rod in the steady-state mode to prevent inadvertent pulses.
The power level scran trip point specified for restricted mode operation is an added protection against fuel temperature exceeding the safety limit for alumninum-clad low-hydride fuel and ensures that the reactor power will not exceed 200 kW.
3.6 Release of Argon-41 Applicability: This specification applies to the release of radioactive Ar-41 from the facility exhaust system to unrestricted areas.
Objective: The objective is to ensure that exposures to the public resulting from the release of Ar 41 generated by reactor operation will not exceed the limits of 10 CFR 20 for unrestricted areas, the ALARA (as low as is reasonably achievable) levels of Appendix I to 10 CFR 50 and the levels of ANS Std. 15.12.
Specification: Releases of Ar-41 from the reactor bay exhaust plenum to an unrestricted environment shall not exceed 32 Ci/ year.
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Bases: The Cornell TRIGArHazardt Analysis (Supplement 1, 1980) shows that the release of 32 Ci/ year of Ar-41 would result in no more than 10 mrem / year expo-sure to any person in the unrestricted area and this is only 2% of the allowable releases that would meet 10 CFR 20 requirements.
3.7 Ventilation System Applicability: This specification applies to the operation of the reactor room ventilation exhaust system.
Objective: The objective is to ensure that the ventilation exhaust shutdown system is operable to mitigate the consequences of the possible release of an uncontrolled arount of radioactive materials to unrestricted areas resulting from reactor operation.
Soecifications: The reactor shall not be operatad unless the ventilation system I i
(including lE shutdown mode) has been shown to be operable. An exception may be made for periods of time not to exceed 2 days to permit repairs to the !
system. During such periods of repair (1) the reactor shall not to operated !
in the pulse mode and (2) the reactor shall not be operated with experiments !
in place whose failure could result in the release of radioactive gases or l aerosols. l Bases: The specifications governing operation of the reactor while the ventila-tion system is undergoing repair preclude the likelihood of fuel element failure l during such times. It is shown in Section 7.4 of the FSAR that, if the reactor l were to be operating at full steady-state power, fuel element failure would l not occur even if all the reactor tank water were to be lost immediately. !
3.8 Limitations on Experiments Applicability: This specification applies to experiments placed in the reactor l and its experimental facilities. ,
l Objectives:
The objectives are, in the event of an experiment failure, to limit reactivity ,
excursions that might cause the fuel temperature to exceed the safety limit. l to prevent damage to the reactor, and to prevent excessive release of radio-active materials.
.e Saecifications: The reactor shall not be operated with experiments in place t1at do not meet the following specifications:
(1) The reactivity worth of any individual experiment shall not exceed 2.00$.
(2) Any experiment with a reactivity worth greater than 1.00$ shall be securely fastened (as defined in Section 1, Secured Experirent).
(3) The total of absolute values of the positive reactivity worth of all experi-ments in the reactor shall be less than 3.00$.
l (4) If two or more experiments in the reactor are interrelated so that opera-l tion or failure of one can induce a reactivity-affecting change in the
! other(s), the sum of the absolute reactivities of such experiments shall l not exceed 2.00$.
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. (5) The rate of planned reactivity addition in any experiment shall be less than 0.07$/sec, except that if the total associated reactivity addition is less than 0.40$, no limit on the rate shall be imposed.
(6) The estimate of reactivity worth of an experiment shall be based insofar as possible on experimental information. If the estimated worth is greater than 0.40$, the actual worth shall be measured and recorded at the time of insertion of the experiment; if the actual value significantly exceeds the estimate, the experiment shall be removed pending review and reapproval.
(7) No experiment shall be conducted that causes local boiling of the core water.
(8) No experiment shall be conducted that causes interference with control rods or shadowing of reactor control instrumentation.
(9) The experiments to be performed have been classified, reviewed, and approved, and are performed, in compliance with rules and procedures set forth in Section 6. (Criteria for fueled, corrosive, explosive, radioactivity-releasing, and otherwise hazardous experiments are dis-cussed there.)
(10) When operating in restricted mode operation, the specifications (1) through (9) above shall apply with two additional restrictions; (a) the reactivity worth of any individual experiment shall not exceed 1.00$, and (b) the total of absolute values of the positive reactivity worth of all experiments in the reactor shall be less than 2.00$.
Bases: Specifications 3.8(1) through 3.8(6) are conservatively chosen to limit unintentional and intentional reactivity additions to maxim;m values that are less than an addition that could cause the fuel temperature to rise above the limiting safety systen set point (LSSS) value. The temperature rise for a 2.00$
insertion is known and is known not to exceed the LSSS. The additional limitations for restricted mode operation are chosen to limit the temperature excursion in a pulse initiated by possible nalfunctions in experinents.
3.9 Fuel Integrity Apolicability: This specification arelies to the fuel used in the Cornell T3.I G A.
Objective: The objective is to prevent the use of damaged fuel in the Cornell TRIGA.
Specification: A fuel element indicating an elongation greater than 1/8 in.
over its as manufactured length or a lateral bending greater than 1/8 in.
shall be considered to be damaged and shall not be used in the core for further operation.
Bases: The above limits on the allowable distortion of a fuel element have been shown to correspond to strains that are considerably lower than the strain j expected to cause rupture of a fuel element and have been successfully applied l at TRIGA installations. Fuel cladding integrity is important since it l represents the only process barrier for the TRIGA reactor. l l
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3.10 Reactor Pool Water A3plicability: This specification applies to the water contained in the Cornell T3 IGA reactor pool.
Objective: The objective is to set acceptable limits on the water quality, temperature, conductivity, and level of the reactor pool water.
Specifications: The Cornell TRIGA shall be placed in the shutdown condition if:
(1) the water temperature exceeds 130'F (2) the water conductivity is greater than 5 umho/cm except that during main-tenance it may exceed that level for no longer than 4 weeks.
(3) the water level above the core is below 181/2 ft., as measured from the top of the core Bases: The water temperature of the reactor pool is limited by the resin used in the mixed bed deionizer.
High water conductivity over a prolonged period indicatcs possible corrosion, demineralizer degradation, or slow leakage of fission products.
A reactor pool level of 18 1/2 ft. is adequate to providing shielding during power operations.
3.11 Restricted Mode Operation Applicability: This specification applies to operation of the rsactor with one aluminum-clad low-hydride thermocouple element in the B-ring and no stainless-steel-clad high-hydride thermocouple element in the core.
Objective: The objective is to define the conditions under which restricted mode operation of the reactor is permitted and the additional restrictions and specifications which that mode requires are to be in force.
Specifications: Restricted mode operation shall be the only pernissible mode of operation when no operable stainless-steel-clad high-hydride thermocouple element is available for use in the core. When an operable stainless-steel-clad high-hydride thermocouple element is available for use in the core, restricted mode operation shall not be used except that during tests of the cladding integrity and measurements of the worth of that element which require reactor operation without that element in the core the restricted mode shall be used.
Bases: The specifications of conditions under which restricted mode operation shall be used limit use of that mode to situations in which operation without a stainless-steel-clad thermocouple element in the core is necessary for brief periods for test purposes or for continuity (though at a reduced scale) of prograns using the reactor. The limits and restrictions required under the restricted mode make it extremely unlikely thet temperatures approaching the safety limits of any element in the core could occur.
12 Amendment No. 9
5.0 DESIGN FEATURES 5.1 Reactor Fuel Applicroility: This specification applies to the fuel elements used in the reactcr core.
Objective: The objective is to ensure that the fuel elements are of such a design and fabricated in such a manner as to permit their use with a high degree of reliability with respect to the;r mechanical integrity.
Specifications:
(1) The high-hydride fuel element shall contain uranium-zirconium hydride, clad in 0.020 in, of 304 stainless steel. It shall contain a maximum of 9.0 weight percent uranium which has a maximum enrichment of 20%. There shall be 1.55 to 1.80 hydrogen atoms to 1.0 zirconium atom.
(2) For the loading process, the elements shall be placed in a close packed array except for experimental facilities or for single positions occupied by control rods and a neutron startup source.
(3) The low-hydride aluminum-clad thermocouple element that can be used only in restricted mode operation shall contain urarium-zirconium hydride, clad in 0.030 in, of aluminum. It shall contain a maximum of 8.5 weight percent of uranium which has a maximum enrichment of 20%. There shall be a ratio of approximately 1.0 hydrogen atoms to each 1.0 zirconium atom.
Bases: These types of fuel elements have a long history of successful use in TRE A reactors.
5.2 Reactor Building A)plicability: This specification applies to the building that houses the TRIGA reactor facility.
Objective: The objective is to ensure that provisions are made to restrict the amount of release of radioactivity into the environment.
Specifications:
(1) The reactor shall be housed in a closad room designed to restrict leakage when the reactor is in operation, when the facility is unmanned, or when spent fuel is being handled exterior to a cask.
3 (2) The minimum free volume of the reactor room shall be 100,000 ft ,
(3) The building shall be equipped with a ventilation system capable of exhausting air or other gases from the reactor room at a minimum of 30 ft.
above ground level.
Bases: To control the escape of gaseous effluent, the reactor room contains The room air is exhausted through an independent no windows that can be opened.
exhaust system, and discharged at roof level to provide dilution, w Amendment No. 9