A technically and programmatically acceptable experiment must be described in sufficient detail to assure that the experiment is performed under the intended conditions, and to furnish an adequate basis for the programmatic review and safety analyses. The main components of the Experiment Plan Package are the experiment objectives, experiment description, and safety analysis. The experimenter is responsible for preparation of all components of the Experiment Plan Package with input from TREAT staff. However, if changes or waivers to the TREAT-approved technical specifications are required, TREAT staff will prepare the safety analyses document with appropriate input from the experimenter. With prior approval from TREAT staff, the experimenter may prepare a single package for a simultaneous or sequential series of essentially identical experiments.
The completed Experiment Plan Package, including incorporation of all prior information gained during feasibility discussions, will be submitted to TREAT staff and subjected to thorough design and safety reviews. Questions and comments that arise as a result of TREAT review of the completed package will be communicated to the experimenter. Depending on the nature of the questions, a response from the experimenter may or may not be required before the experiment is approved for installation at TREAT.
The final Experiment Plan Package must be approved by TREAT prior to finalizing fabrication and shipment of experiment materials. The requirements in this Section 5 must be included at a minimum. TREAT staff may add additional requirements as needed based on individual experiment needs defined during discussions between the experimenter and TREAT staff.
5.1 Experiment Objectives
5.1.1 Test Objectives and Requirements
Provide a brief explanation of why the experiment is important and the significance of the data that will be obtained. How objectives will be achieved, a high level timeframe of when major activities will take place, and where the various elements of the work will be done should also be included.
5.1.2 Test Conditions
Provide a description of the reactor power transient requirements and the experiment thermal and flow requirements with the acceptable range of these parameters specified.
5.1.3 Physical Description of the Experiment Hardware
Describe of the experiment hardware system through the use of tables, figures, specifications, and narrative. Each of the following systems should be discussed in sufficient detail to support the functional, design, operation, and safety feasibility of the experiment.
Test specimens (fuel pins, calibration wires, foils, etc.)
Test train (internal structure supporting the test specimens and instrumentation)
Instrumentation (type, number, range of measurement, range of accuracy)
Test vehicle (pressure boundary and containment system)
Auxiliary systems (pumps, heat exchangers, storage, air, etc.)
5.1.4 Pretest Operations
Describe the required pretest operations needed in preparing the experiment for irradiation. Consideration should be given to vehicle and test train assembly, fuel loading, checkout, testing, and any other pertinent operations. TREAT staff will provide information and identification of the appropriate support facilities where the specific activities will be handled.
5.1.5 Test Operations
Describe the functional nature of each test run, the sequence of physical events expected during the experiment irradiations, and specify the number and type of separate reactor transients. Include the sequence of operations to be conducted by TREAT (e.g., calibration runs, heat balance runs, radiography, insertion and withdrawal of flux monitor wires, hodoscope operations, extracting physical samples, etc). This information is necessary for TREAT staff to communicate with other support organizations and ensure availability as required to support the experiment.
5.1.6 Post-test Phase
Include the entire sequence of operations involving the experiment system including disassembly, loop stripping, radiography (gamma or neutron), sectioning, examinations, storage, and disposal. If these activities cannot be handled at TREAT, additional information will be provided to support finalizing the Experiment Plan Package.
5.1.7 Documentation
Include a complete list of documents that will be produced in connection with the experiment. The documents required by this Guide, by INL policies, or by parent organization policies and procedures, should be identified. TREAT staff will assist the experimenter with ensuring INL-specific requirements are understood for inclusion.
5.1.8 Quality Assurance
Describe whether or not the INL Quality Assurance Program applies without exception to this experiment or if a project specific Quality Assurance Program Plan (QAPP) will be developed. If there are experiment specific requirements and will not be placed in a QAPP, they must be listed in this section. TREAT staff will provide additional information as needed.
5.1.9 Safety Considerations
Provide a summary listing of general safety feasibility and safety approval requirements for the experiment, including information gained from discussions during the feasibility review. Considerations of particular concern should include precedents of previous experiments, plutonium content and disposition, primary pressure boundary integrity, levels of containment, TREAT reactivity effects, operational radiation hazards, and any other specific items that may have a bearing on experiment safety feasibility. This section is a summary to help identify the need for a preliminary safety review and approval. The detailed safety analysis is addressed in Section 6.
5.1.10 Environmental Considerations
Complete the INL Environmental Checklist and submit to TREAT for review and approval prior to experiment initiation. All experiments performed at INL must be in compliance with the National Environmental Policy Act (NEPA) as required by DOE Order 5440.1 and the INL Health and Safety Manual. Each experiment to be performed as part of an existing Experiment Plan Package must have an individual completed and approved Environmental Checklist. This completed form should be submitted early in the experiment planning process to allow appropriate review times and avoid delays to the experiment schedule. An example of the checklist for information and planning purposes can be accessed via the link in the right hand column. The current active Environmental Checklist will be provided to the experimenter by TREAT staff.
5.1.11 Experiment Schedule
The experimenter, with input from TREAT staff, will finalize target dates for the key events associated with each experiment. TREAT staff will supply a template to assist the experimenter with defining the key events and targets based on individual experiment needs. Additions or changes to the list of events can be made throughout the experiment planning process to reflect specific aspects of a given experiment. Every effort is made to run experiments per the agreed upon schedule, but short-term conflicts are inevitable. TREAT reserves the right to adjust scheduled experiment activities in a manner that ensures the overall operating efficiency of the Reactor. In the event of longer-term scheduling conflicts, the matter will be discussed and a solution agreed upon between the experimenter and TREAT.
5.2 Experiment Design Requirements
Include detailed design requirements and a functional description of all major components, including the principal functional and interfacing requirements of each. Design requirements should be supported by documented calculations and analyses. Pertinent supplemental documents, such as design drawings, must be prepared and provided to TREAT staff.
A test specification procedure is required for each separate test. When an experiment includes a series of similar tests, one general test specification procedure should be prepared for the series and detailed requirements for each individual run listed in an addendum to be submitted prior to each experiment. The most current test specification template will be provided to the experimenter for completion and submission to TREAT.
5.3 Safety Analysis
The primary purpose of the safety analysis for each experiment is to ensure the proposed experiment can be conducted at TREAT without undue risk to the general public, operating personnel, the Reactor or facility. Since many TREAT experiments are designed to investigate the interaction of fuels and coolant materials at temperatures well above those attainable in the laboratory, methods are often not available to realistically predict what might happen during a planned experiment or under accident conditions. Therefore, very conservative assumptions must often be used in the safety analysis to compensate for the lack of basic data on which to base a more realistic analysis. Obviously, an experiment is more likely to be found acceptable if the safety analysis clearly shows that primary containment failure is very unlikely under any credible accident condition.
Items that must be considered in each safety analysis are listed in this section, but unlisted factors may be of importance to some experiments, and it is the experimenter's responsibility to identify all factors that have a bearing on the safety of the experiment. Abnormal operating conditions may exist and the possibility will be discussed as experiment planning proceeds. When previous experiment results are relevant to those under consideration, information that may prove useful will be provided to the experimenter by TREAT staff.
5.3.1 Anticipated Results of Experiment
A descriptive summary of the anticipated results of the experiment when the Reactor operation and the experiment operation requirements have been met shall be given. At a minimum, these results should include fuel failure, fuel motion, temperatures, pressures, coolant flow, and any other significant parameters associated with the experiment.
5.3.2 Nuclear Effects on Reactor Performance
Materials inserted for the experiment may have considerable effect on the reactivity of the Reactor. Therefore, the following effects must be estimated:
The gross effect of loading the experiment into the reactor,
The effect on control-rod worth,
The effects of expansion, displacement, or rearrangement of materials within the experimental container, and
The effects of movement of experimental apparatus by forces generated within the apparatus such as from sodium or water hammer.
The TREAT staff will estimate these effects using experimental data from other experiments and computer codes when necessary; the experimenter need not supply calculations of these effects. However, if the experimenter obtains reactivity information as part of the output from computer calculations made to establish experiment feasibility, the data should be included. In any case, the experimenter shall supply information such as material composition and credible configuration changes in sufficient detail to permit the TREAT staff to make the reactivity calculations outlined above using standard computer codes. Since these reactivity effects only need to be estimated to an accuracy of about 10% of the total effect, nominal material-composition data are usually all that are required.
5.3.3 Energy Release Calibration Factor
A calibration factor is required between the sample energy release and the reactor energy release to determine the necessary reactor transient conditions to obtain the correct energy release within the test sample, and the uncertainty in this factor must be considered in the safety analysis. An important consideration in the uncertainty of the calibration factor is the potential effects due to nonuniformity of neutron filters from one test vehicle to another and within various regions of a given vehicle when neutron filters are used. Generally, an experimental verification of the calculated calibration factor is required if the safety analysis is at all sensitive to the calibration factor. An experimental verification of the calculated calibration factor is required unless the energy depositions are less than 25% compared to the energy containment capability of experiment hardware.
If rearrangement of the fissile material during a transient could significantly change the calibration factor, the effects of the changing calibration factor during the transient shall be considered in the safety analysis. Typical rearrangements could result in decreased self-shielding and/or loss of neutron filter effectiveness.
The experimental verification of the calibration factor can be accomplished in various ways. Usually it is done by a radiochemical-analysis method or a heat-balance method. The radiochemical-analysis method requires the use of an identical fuel sample that can be irradiated in TREAT for a given time at steady-state power. The fuel sample can then be analyzed for the total number of fissions for the given reactor energy release. When preirradiated fuel is to be in an experiment, the calibration fuel should represent the fuel in the experiment to the degree practicable with the appropriate correction calculated.
The heat-balance method requires the use of thermocouples in the experimental vehicles. A vehicle is placed in the reactor and during a given reactor energy release, either at steady-state or in a small transient, the temperatures are recorded for each thermocouple. An energy generation or generation rate in the fuel is then calculated from the temperature data.
5.3.4 Mechanical Failure of Experimental Equipment in the Reactor
Mechanical failure of experimental apparatus can affect the Reactor in many ways, all of which shall be evaluated. The following types of credible failures, which could release radioactive or toxic materials, disable control rods, or prevent removal of the apparatus or fuel elements by normal methods, must receive consideration for the reactivity accident case and any other credible situations which might cause any type of mechanical failure of the experiment apparatus.
Explosion or rupture of the experiment containment vessel
Melting of experimental apparatus, fuel sample, or flux monitors; including liquefaction by the formation of eutectic mixtures
Loss, displacement, or melting of neutron filter
Expansion or distortion of experimental apparatus
Failure of connecting services to experimental apparatus such as oil, electrical, water, air, or inert-gas systems
Mechanical loading of reactor components by reaction forces generated by motion of materials within the experimental vehicle
Handling accidents during installation or removal from the reactor
5.3.5 Mechanical Hold-down
The need for a mechanical hold-down on the test vehicle must be approved by TREAT staff prior to fabrication and use.
5.3.6 Temperature of TREAT Fuel Cladding
The temperature of the cladding of the TREAT fuel adjacent to the experiment shall be evaluated under normal and maximum accident conditions and shall not exceed the limits specified by TREAT staff.
5.3.7 Experiment Vehicle Integrity
Analysis of the vehicle design shall show that the vehicle will retain its integrity under the conditions as defined by TREAT staff.
5.3.8 Handling of Experimental Apparatus
Handling procedures will be carefully evaluated. Equipment that could become radioactive during the experiment will be given special attention by TREAT staff. Hazards to personnel, the Reactor, and the TREAT Facility will be thoroughly considered.
5.3.9 Chemical Reactions
Chemical reactions that have the potential to cause injury to personnel or damage to equipment or the reactor facility will be thoroughly analyzed by TREAT staff prior to approval. The following are examples of the types of reactions considered:
Metal-water reactions,
Liquid-metal fires,
Corrosion of reactor materials caused by release of materials from the experiment, and
Decomposition of material into other forms, e.g., elemental, gaseous, toxic.
5.3.10 Radiation Hazards
Personnel exposure from the following types of radiation hazards shall be evaluated for capsule handling, radiography, reactor insertion and removal, shipping, and receiving:
Direct radiation from contained materials,
Contamination by particulate matter, and
Release of radioactive gases.
5.3.11 Disposal and/or Release of Radioactive and/or Hazardous Material
The disposal and/or release of radioactive, hazardous or mixed waste material before, during, or after the experiment is the responsibility of the Experimenter unless explicitly accepted by TREAT. There is limited storage availability at the INL and all environmental impacts must be resolved before beginning an experiment to ensure full compliance with applicable Federal and State regulations.
5.3.12 Reactivity Accidents
Although extensive precautions are taken to prevent reactivity additions significantly greater than those requested for the desired transient test, reactivity-insertion errors are credible. Therefore, the effect of reactivity-insertion errors must be considered in the design and safety analysis of each experiment. Two types of transient experiments are to be considered: unshaped and shaped. Unshaped transients are ones in which the only reactivity addition is that required to initiate the transient. Shaped transients are ones in which reactivity additions are required following the addition of reactivity to start the test. The assumptions to be used in analyzing the effects of the maximum unplanned reactivity additions for the two types will be provided to the experimenter by TREAT staff.
If the experimenter plans to make the analysis of the reactivity accident, TREAT staff will provide the appropriate reactor power and energy release data for the analysis. However, if the experimenter plans to make the accident calculations, concurrence should be obtained from TREAT that the calculations will be acceptable for the safety analysis. Due to the complex nature of many shaped transients, the experimenter must obtain concurrence from TREAT staff on the definition of the reactivity accident prior to completing a safety analysis.
Although the maximum reactivity accident will provide the greatest energy input into the experiment, other control system malfunctions could cause power levels higher or lower than desired and these types of malfunctions must be considered in the safety analysis to show that they could not cause loss of containment. For example, a control system malfunction that permits the fuel to operate at higher than expected power levels during a flat-top transient might cause slow and nonÂdispersive fuel melting, which in turn could cause melt-through of the test vehicle.
5.3.13 Final Design Disclosure
The experimenter shall submit a documentation package that provides a disclosure of the final experiment system design in terms of the specific hardware articles to be employed in the experiment, including any and all documents sufficient to describe the hardware as delivered to TREAT. This package shall include drawings of the assembled and outfitted test hardware along with copies of all inspection disposition records (IDRs) covering the identity and disposition of any deviations to safety related components generated in the assembly/outfitting process. In addition, the drawings followed in fabricating the separate hardware components that comprise the pressure boundaries, neutron attenuating components, thermal-energy retention, and all other safety-related components shall be furnished, along with all document change notices (DCNs) and IDRs, pertaining thereto.
Separately from the above, the experimenter shall supply documents, including drawings, which describe the ancillary systems, experiment accessories, and other components that TREAT and the other support facilities will be required to handle and operate. These documents shall be sufficiently detailed to allow personnel to maintain, operate, and modify these systems as needed and/or requested. The experimenter responsible for providing each such accessory shall maintain these documents up-to-date.
The following items relevant to the final design disclosure shall be provided to TREAT staff as part of the safety analysis:
Documentation shall be provided that ensures that the specific test hardware assembly has been fabricated, assembled and outfitted in accordance with drawings, materials, and specifications considered by the experiment safety analysis. Examples of the type of documentation to be included are certification(s) covering hardware fabrication, assembly, and outfitting; pressure testing; fuel-pin loading; neutron filter and shaping-collar composition, location, and attachment details; final leak testing; and testing and inspection results. A neutron radiograph of the completed experiment assembly is normally required before insertion of the experiment into the reactor. Justification for not radiographing an experiment shall be considered.
Documentation shall be provided stating that the experiment safety analysis has considered any deviations, changes, discrepancies, or exceptions made to either the reference drawing requirements or to the specifications, which could lower the safety capabilities of the individual loop components or an assembled loop. The documentation shall include a listing of the component drawing numbers, including their revision numbers, as well as all DCNs and IDRs pertinent to the safety features of the affected components. Further documentation shall be provided to state that safety-related deviations from the controlling requirements (drawings, etc.), made during outfitting or assembly of the loop, have been evaluated relative to the safety analysis by the analyst who prepared the safety analysis.
5.3.14 Safety Analysis Summary Sheets
TREAT staff will provide the most current safety analysis summary sheets, one for the first experiment in a series, and one for an onÂgoing experiment in a series to the experimenter. An appropriate summary sheet shall accompany each safety analysis in the Experiment Plan Package. This will summarize the information given in the safety analysis concerning the test fuel, specified transient, accident-case transient, and containment safety margin. The summary sheets will also aid the reviewer in locating the pertinent data in the present safety analysis and also in the referenced safety analysis for an ongoing series of experiments.
5.3.15 Reuse of Experimental Hardware
An engineering analysis shall be provided for all hardware that has been previously used in a TREAT experiment and that is addressed in the safety analysis. This analysis shall demonstrate that the integrity of the hardware has not been degraded by previous tests and that it is satisfactory in all respects for another transient irradiation test. Factors such as temperature cycles, pressure cycles, residual fissionable material, contamination and/or activation levels, seal integrity, shipping and/or handling accidents, etc., shall be addressed along with any other factors that are relevant to safety. A complete use history also shall be provided upon request.
5.3.16 Unreviewed Safety Question Determination
TREAT is required by DOE to submit an unreviewed safety question (USQ) whenever a proposed experiment falls outside the safety envelope established in SAR-420. The Experiment Plan Package shall contain the necessary information to permit the following determination. TREAT staff will provide additional details and guidance to assist the experimenter in ensuring this requirement is met.
5.3.17 Programmatic Review and Approval
The Experiment Plan Package will be reviewed by TREAT and may include other INL organizations and personnel as appropriate. Review reports shall summarize concerns raised during reviews, their resolutions, any commitments made, and final conclusions. The Experimenter will be informed of review findings and requested to perform any needed changes to finalize the Experiment Plan.
Once the final Experiment Plan has been agreed to by the Experimenter and TREAT a written approval will be issued. TREAT will share the final plan with TREAT staff and support facility staff as appropriate for planning and scheduling.
