ML19256F729
| ML19256F729 | |
| Person / Time | |
|---|---|
| Site: | University of Missouri-Rolla |
| Issue date: | 12/11/1979 |
| From: | MISSOURI, UNIV. OF, ROLLA, MO |
| To: | |
| Shared Package | |
| ML19256F726 | List: |
| References | |
| NUDOCS 7912200463 | |
| Download: ML19256F729 (22) | |
Text
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I Technical Specifications I
University of Missouri-Rolla Reactor I
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1628 227 I
I 7912200 463
I Technical Specifications I
for University of Missouri - Rolla Nuclear Reactor l
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Table of Contents Technical Specifications for the UMRR General 1
Definitions 1-2 Safety Limits 2-3 Conditions for Operation 3
Instrumentation 4
Control 4-5 Table 1 Safety and Control Instrumentation 5-6-7 Radiological Monitoring 8
Reactor Water 8-9 Surveillance 9-10 Console 10 Radiation Monitoring Equipment 10-11 Maintenance 11 Reactor Fuel 12 Speci fications 12-13 Fuel Storage 13 Administrative and Procedural Safeguards 14-15 Modi fication and Maintenance 16-17 Core Loading Patterns 18 1628 229 I
Technical Specification for the UMRR I
General Reactor Identification The University of Missouri - Rolia Reactor (UMRR) is a pool type reactor, fueled with MTR type 90% enriched fuel, and/or 20% enriched Triga fuel. The reactor is housed in a building designed for a controlled release of effluents.
The reactor is located on the campus of the University of Missouri - Rolla and is owned and operated by the Board of Curators.
Accuracy The numerical values given in these specifications may vary from measured values due to the normal accuracy of the instrumentation and or measuring devices.
Definitions Reactor Shutdown Reactor shutdown shall mean that sufficient control rods are inserted so as to assure the reactor is subcritical by at least 1%.
Reactor Secured Reactor secured shall mean that conditions exist wherein:
1.
The reactor is shut down.
2.
The magnet power is off and the key removed from the console.
3.
The shut down check list is complete.
Operable A system or device will be construed to be operable when it is capable of performing its intended function in a normal manner.
Cold Clean Critical 1628 230 Cold Clean Critical shall mean the critical condition that exists when the temperatures of the reactor fuel and pool water is at ambient temperature and
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_2 that no appreciable amount of fission products are present in the core.
Experiment Any apparatus, device, or material placed in the neutron flux of the reactor. An untried experiment shall mean an experiment which has not been previously run in the UMRR.
Experimental Facility An experimented facility shall mean the thermal column, pneumatic tubes, i z reactor core, sample rotor or other devices designed to hold, position or a
expose samples for irradiation purposes.
Reactor Safety Circuits Reactor safety circuits shall mean those circuits, including their asso-ciated equirment, which are designed to initate a reactor scram.
Steady State Operation Steady state operation shall mean that operation of the reactor in which the power is held constant and the reactor is on automatic control.
Direct Supervision Direct Supervision is defined as the supervisory personnel being in audible and visual contact with the person or persons being supervised.
Safety Limits Applicability This specification applies to the power level and the rate of change of power.
Objective To insure the integrity of the fuel and to prevent the release of fission products from the fuel.
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_ Specifications The reactor power shall not exceed 200 K.W. + the normal accuracy of the instrumentation as indicated by the Intermediate Range Linear Nuclear Instru-ment Channel.
The rate of the reactor power increase shall never be faster than a 15 second period.
I Conditions for operation Reactivity Limits Excess reactivity above Cold Clean Critical shall never exceed 3.5%, and this maximum shall never be used except for control rod calibration.
The excess reactivity at an other time shall not exceed 1.5%.
The reactivity worth of any single independent experiment shall not exceed 0.7%.
The reactivity worth of all experiments in the core that are designed to be moveable shall not exceed 0.4%.
Reactor operation by student personnel will not be permitted when the excess reactivity of the core is greater than 0.7%, excepting those students who are in operator training courses and then the excess reactivity shall not exceed 1.5%.
Bases The reactivity limits have been designed to give adequate excess reactivity to overide the negative temperature coefficient and to permit irradiation of experiments.
Limits on experimented worths provide an adequate shut down margin in the event an experiment is accidently expelled from the reactor, and to avoid reactor excursions gre>ter than would be expected from normal operation.
The shut down margin assur;s that the reactor can be shut down should any one of the trippable control rods become stuck in the fully withdrawn position.
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Instrumentation Applicability This specification applies to the devices which provide information on power level, rate of change of power, rate of change of subcritical neutron flux and pool temperature.
Objective The objective is to assure the information available to the operator concerning reactor operations within permissible limits.
Specifications 1.
There shall be at least one thermocouple positioned to read the core inlet temperature, and at least one thermocouple positioned to read the core outlet temperature.
2.
There shall be at least five neutron measuring chambers located adjacent to the core.
These will present neutron level information to the console.
Bases Since the pool water temperature has an effect on the core reactivity it is important that the information be available at all times.
Neutron flux is an important parameter for a reac r since it is directly proportional to the power level. The start up channel covers the source range while the other channels will provide reliable information after criticality through full power.
Control Applicability This specification applies to the control system including the control rods, control rod drives, and the control console.
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- Objective The objective is to provide a system that will insure control by the operator or control within the prescribed limits should the operator fail to function correctly.
Specifications 1.
The control system shall include a minimum of four control rods, one of which is designated as a regulating rod which shall have a worth of no more than 0.7%.
The gang worth of the three other rods shall be greater than 7%.
The maximum drop time shall not exceed 600 milliseconds from scram initation to full insertion.
The regulating rod shall be connected to a control device that will allow automatic control for steady state operation.
Safety and Control Instrumentation TABLE I SAFETY AND CONTROL INSTURMENTATION Unit Initi-Resulting Situation Detector ating Action Action Setpoint Manual Scram Operator Scram Button Scram operator Period 5 seconds Compensated Log N & Period Scram
>5sec or less Ion Chamber Amplifier 150% Full Power (2) Uncompen-Safety Amplifier Scram
<l50%
or more sated Ion Chamber Bridge Motion Motion Switch Motion Switch Scram
<l/4 inch Log N & Period Log N Period Relay Scram N/A Amplifier NOT Amplifier Operative 120% Demand Compensated Linear Recorder Rundown
<120%
or more Ion Chamber 1628 234 Table I (continued)
Unit Initi-Resul ting Situation Detector ating Action Action Setpoint Period 15 seconds Compensated Period Recorder Rundown
>l5 sec or less Ion Chamber Regulating Roo Micro-Switch Micro-Switch Rundown
>0.0 Insert Limit on Auto.
Low CIC Vo!tage DC Realy DC Realy Rundown
>400v 120% Full Power Compensated Log N Recorder Rundown
<l20%
or more Ion Chamber High Radiation GM Tubes Remote Area Rundown
<l5 mr/Hr I
at RAM Points Monitoring (1,2,3)
(RAM) System I
Period 30 seconds Compensated Period Recorder Rod Prohibit >30 sec or less (2)
Ion Chamber Any Recorder Off Realy Relay Rod Prohibit N/A (4)
Log Count Rate Fission Log Count Rate Rod Prohibit
>2 cps I
2 CPS or less Chamber System (2)
I Safety Rods Below Micro-Switch Relay Rod Prohibit N/A Shim Range or Regulating Rod Above Insert I
Limit (2)
Reactor Power Compensated Linear Channel Servo-N/A I
Deviation More Ion Chamber Recorder Prohibit than 5% of Selected Power Level Core Inlet Water Thermocouple Pselay Rod Prohibit <135 F Temperature I
135 F or more Interlock Key Switch Key Switch N/A Bypassed Effluent Pool Conductivi ty Relay
<0.5 megohms Demineralizer Bridge per cm Conductivi ty O.5 Meg Ohms I
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Table I (continued Unit Initi-Resul ting Situation Detector ating Action
- Actio, Setpoint High Neutron Flux BF 3 Neutron Relay
<10,000 in Beam Room (3)
Detector cpm I
(1) Radiation detector on the reactor bridge causes building alram.
(2)
Indicates that the situation may be key bypassed around safety circuitry.
(3) These will be set by measurement during initial increase in power level.
The set-points will be less than 30 mrem /hr.
(4) The drive motor on startup channel recceder may be off.
Scram Circuits The scram circuits are designed to shut down the reactor quickly in the event of a power excursion, a rapid increase in period, failure of the period detection equipment and the manual scram provides an overide of the automatic circuits.
The bridge motion scram is designed to scram the reactor in the event of motion of the reactor core.
I Rundown Circuits Rundowns are designed to shut down the reactor automatically due to higher than normal levels.
Faster flux change than normal, loss of power to the neutron detectors and to preclude the use of the automatic control when the regulating rod is not in a position to provide the needed reactivity for con-trol. Also included in the rundowns are high radiation levels in several areas of the reactor building.
Rod Prohibits The rod prohibits precludes the possibility of withdrawing rods due to the lack of source neutrons, operation with any recorder off, excessive period or excessive pool water temperature.
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Radiological Monitoring Applicability This specification shall apply to the radiation monitoring system of the facility.
I Objective The objective is to provide information about the radiation levels in the building and to provide the necessary alarms in the event the set limits are exceeded.
Specifications There shall be a minimum of three radiation monitors one on each level of the facility indicating the general radiation levels around the building.
At least one of the three monitors shall shut down the reactor au toiiiatically in the event the prescribed radiation level is exceeded.
All three of these monitors will have readouts in the control room.
Bases It is important to be constantly aware of the radiation levels in the facil i ty.
An adequate alarm system must be provided to warn personnel of any impending or existing danger from radiation, and that will allow sufficient time to evacuate the building.
Reactor Water Applicability This specification pertains to the reactor pool water.
I Objective The objective is to ensure that the temperature of the pool water does not exceed the recommended operating temperature of the demineralizer resins.
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Specifications The reactor shall not be operated when the bulk pool water temperature exceeds 57 C.
Bases It is desirable to operate the reactor with a temperature that will not harm the demineralizer resins. Water purity is an unnecessary technical specification for reactor safety. Although impure water will accelerate corrosion it will not produce an unst:e condition, merely an inconvient one.
Surveillance Control Rods Applicability This surveillance specification shall apply to the control rod system for the reactor.
I Objective The objective is to insure the integrity of the three trippable control rods.
I Specifications The measurement of the control rod worth shall be made semiannually but at intervals not to exceed eight months.
The control rod drop times shall be made semiannually but at intervals not to exceed eight months.
A visual inspection of the control rods shall bc at intervals not to exceed two years.
Bases In order to determine the reactivity worth of experiments and the reactivity worth of various cores the control rods should be calibrated periodically.
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-9a-Radioactive Releases In order to comply with ALARA a water retention system shall be used to retain the liquid effluents from the water purification system.
The waste water is held until well below 10-CFR-20 Appendix B, Table 1 Column 2 limits for unrestricted release.
Gaseous effluents are constantly monitored and total releases are calculated monthly. Liquid effluents are calculated each time a release to the sanitary sewer is made.
While operating at full power gaseous effluents are well below the level for unrestricted release.
I The detailed methodology for measuring and calculating the effluents is given in the operating procedure and is approved by the Health Physicist.
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I The rod drop times must be measured in order to determine the emergency shut down time.
The visual inspection of the control rods are necessary to detect any metallurgical problen 5.
Console Applicability This specification applies to the reactor control system, its safety circuits and start up instrumentation.
Objective The objective is to insure the realibility of the reactor control and safety system.
Specifications The reactor safety circuits and start up instrumentation shall be checked as operable prior to each days operation, and/or before each start up after the reactor has been secured.
The calibration of power level will be made semiannually but at periods not to exceed eight months. The alignment of all console instruments shall be made semiannually but at periods not to exceed eight months.
Bases This requirement assures the reactor operator that the information presented to the consolers correct, allowing the operator to make correct judgements concerning the operation.
The power calibration will assure the maximum power limits will be met.
Radiation Monitoring Equipment Applicability This surveillance specification shall apply to the radiation monitoring equipment in the reactor building.
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Objective The objective is to insure that the radiation monitoring equipment is functioning and that the alram settings are reasonable.
Specifications The alarm set points for the radiation monitoring instrumentation on the console shall be checked prior to starting up the reactor for each days oper-ation. Other monitoring equipment shall be checked on a weekly basis during normal operating periods.
Bases The procedures for emergency evaluation involve signals from the radiation monitoring equipment checking of that system is needed for both radiation con-trol and emergency procedures.
Maintenance Applicabili ty This specification applies to the surveillance requirements following maintenance of control or safety systems.
Objective The objective is to insure that the control or safety system is operable and calibrated before being used after maintenance.
Specifications Following maintenance or modification of the control or safety system, an operational and/or alignment of the associated system shall be performed before the affected system is to be considered operable.
Bases Any time that maintenance or modification of a system is required, it is necessary to know if the system has been returned to a normal operating status before the reactor is brought to power.
. _.. _ Design Features Reactor Fuel Applicability This specification shall apply to the fuel elements in the reactor core.
Objective The objective is to insure 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 their mechanical integrity.
Specifications MTR Fuel Element The standard MTR fuel element contains 10 plates.
The overall demensions of each element is approximately 3 X 3 X 36 inches.
There is approximately 235 17 grams of U per plate.
Each plate is 24 inches long and clad in 20 mils of aluminum.
The entire assembly is joined at the bottom to a cylindrical nose piece that is machined to fit into the bottom grid plate.
Two identical elements which contain only five plates with fuel are designated as half elements.
MTR Control Rod Element The standard MTR Control rod elements are identical to the fuel element with the exception that the center four plates have been removed and have been
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replaced with a guide for the control rod.
In addition the fuel plate spacing is slightly closer than in a standard element.
Standard Triga Fuel Element The Triga fuel elements consist of a cluster of four rods mechanically joined together to form a fuel element of the same demension of a MTR tuel element.
Each fuel rod is 30 inches long with an overall outside diameter 1628 242 of 1.41 inches. The fuel length is 15 inches and the entire rod which is clad is 20 mils of stainless steel.
Each rod contains approximately 35 grams of 235 U
with a 20% enrichment. The fuel composition is Uranium-Zirconium hydride.
Loading The fuel elements shall be placed in a closely packed array except for positions occupied by control rods and a neutron start up source.
Bases Both the MTR and Triga type fuel has a long history of successful use.
Operation with a mixed core will yield necessary data on different enrichments.
Fuel Storage Applicability This specification shall apply to the storage of reactor fuel at times when it is not in the core.
Objective The objective is to insure that fuel which is being stored will not become supercritical.
I Specifications All stored fuel elements shall be stored in a geometrical array where the K
is less than 0.6 for all conditions of moderation.
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Bases The fuel elements must be stored in such a fashion to preclude any possi-bility of criticality.
I 1628 243 Administrative and Procedural Safeguards Isotopes and Safety Committee This committee is directly responsible for the safe operation of the Nuclear Reactor Facility.
It reviews and approves all projects utilizing the I
facility and reviews and approves all proposed changes to the facility.
The committee is also responsible for determining whet er a proposed change, test, e:geciment would constitute an unreviewed safety question or a change in nr technical specifications.
The membership of the committee shall be such as to maintain a high degree of technical expertise, and shall meet at least at I
quarterly intervals.
Operation and Written Procedures The following operations shall be done only in accordance with written instructions.
1.
Checkout and calibration of reactor operating instrumentation.
2.
Reactor start up and sh:
iwn.
3.
Control rod removal for inspection.
4.
The loading and unloading of fuel, except for the removal of loading I
of a single element.
Record Retention The following records shall be retained for at least five years:
Records and logs of principal maintenance activities, inspections, repair and replacement of principal items of equipment related to nuclear safety.
I ALL REPORTABLE OCCURRENCES submitted to the Commission.
Records of surveillance activities, inspections and calibrations required by these Technical Specifications.
Records of reactor tests and experiments.
jg}g }44 Records of radioactive shipments Records of sealed source leak tests and results.
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__ The following records shall be retained for the duration of the Facility Operating License:
Records and drawing changes reflecting facility design modifications made to systems and equipment described in the Hazard Analysis Report.
Records and logs of facility operation covering time interval at each power level on the Log N recorder only.
Records of new and irradiated fuel inventory, fuel transfers and assembly burnup histories.
Records of facility radiation and contamination surveys.
Records of radiation exposure for all individuals entering radiation con-trol areas.
Records of gaseous and liquid radicactive material released to the environs.
Records of training and qualification for current members of the plant staff.
Records of meetings of the Radiation Safety Committee.
1628 245 Modifications and Maintenance Any additions, modifications or maintenance to che core, its supporting struc-ture, rod drive mechanisms or the reactor safety system shall be made in accordance with the specifications not to exceed the original design of the systems, or the specifications approved by the Safety Committee as suitable and not involving an unreviewed safety question. A system shall not be considered.
Experiments Any proposed project utilizing the neutron flux of the reactor shall be evaluated by the experimenter. The evaluation then shall be reviewed by a licensed Senior Operator and the Reactor Health Physicist to assure compliance with the provisions of the utilization license, tech specs, and 10 CFR 20.
If in their judgement it meets with the above provision and does not constitute a threat it to the Safety Committee for final approval. When pertinent the evaluation shall include:
The reactivity worth of the experiment, including the effects of changes of temperature, pressure, or chemical composition, and any radiation hazard that may result from its interaction with the neutron flux.
After a project request has been given final approval by the safety committee, each individual experiment in the project shall be approved by at least two persons, one of which is a member of the health physics staff, the other a licensed Senior Operator of the facility.
For the approval of an experiment the experimenter must submit an "Irradi-ation Request Form" to the Reactor Manager or the Health Physicist. The request shall contain information to the target material, amount, chemical form, and packaging.
For routine irradiation which do not contain nuclear I
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fuel or explosive materials and which do not constitute a threat to the intergrity or safety of the reactor or personnel: approval for the irradiation shall be made by a licensed Senior Operator and the Reactor Health Physicist or his designee.
Samples must be doubly encapsulated when the release of the contained material could cause corrosion of the experi-mental facility.
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1 Core Loading Patterns I
Applicability This specification shall apply to studies of core loading patterns using mixed Triga and MTR fuel.
I Objective To insure safe operations with a mixed core.
Specifications 1.
All movements of fuel shall follow written procedures and will be done under the direct supervision of a licensed Senior Operator.
2.
The loading of fuel elements into any position shall be done with the safety rods halfway withdrawn (Shim Range).
3.
The maximum excess above cold clean critical shall not exceed 1.5%.
4.
The maximum steady state operation during the study shall not exceed 100 kilowatts.
Previous to any operation above 100 watts during these studies the critical rod heights shall be determined by operating the reactor at low power for a period long enough to determine cold clean critical excess react-ivity.
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