ML16040A310
| ML16040A310 | |
| Person / Time | |
|---|---|
| Site: | Armed Forces Radiobiology Research Institute |
| Issue date: | 02/09/2016 |
| From: | Miller S US Dept of Defense, Armed Forces Radiobiology Research Institute |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC ME1587 | |
| Download: ML16040A310 (11) | |
Text
ffM1j ARMED FORCES RADIOS IOLOGY RESEARCH [NSTITUTEm~i8001 WIIcoNUIN AvI[NUI[*K[THKISDA, MAIRYIAJND 20689-8603 %~February 9, 2016Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING THEAPPLICATION FOR LICENSE RENEWAL (TAC NO. ME1587)Sir:By letter dated November 2, 2015, the Nuclear Regulatory Commission requestedadditional information necessary to allow processing of our research reactor licenserenewal application (License R-84, Docket 50-170). Answers to those questions areenclosed.If you need further information, please contact Mr. Steve Miller at 301-295-9245 orstephen.miller@usuhs.edu.I declare under penalty of perjury that the foregoing is true and correct to the best of myknowledge. Executed on February 9, 2016.Ste hn l erReactor Fa .ility DirectorUC1v-o REQU EST FOR ADDITIONAL INFORMATIONFOR THE LICENSE RENEWAL FORTHE ARMED FORCES RADIOBIOLOGY RESEARCH INSTITUTETRIGA REACTOR FACILITYLICENSE NO. R-84DOCKET NO. 50-1701. NUREG-1537, Part 1, Section 13.1.2, "Insertion of Excess Reactivity," lists insertion-ofexcess-reactivity events, one of which is the ramp (slow) insertion of reactivity by drivemotion of the most reactive control rod or shim rod, or ganged rods. Your RAl responsedated April 20, 2012 (ADAMS Accession Nos. ML12122A146 and ML15296A451), asamended on September 21, 2012, (ADAMS Accession No. ML12272A303), stated that"The instantaneous insertion of $3.00 (2.1 % delta k/k) to the reactor core as a result of aworst case reactivity insertion is bounded by the analysis of the $3.50 (2.45% delta k/k)pulse limit and would not result in any adverse safety conditions within the AERRI TRIGAcore."~Your response did not completely address a ramp insertion analyses. Provide a detailedramp analysis ~ientifying the maximum power level and fuel temperature experiencedduring the transient. Assume that the first scram, which would terminate the reactivityinsertion, would fail in accordance with single failure criteria. Identify which reactor tripterminates the event and its associated response time, including the scram time of thecontrol rods, in order to demonstrate the protection of the safety limit.The following information is offered in addition to the information submitted April 20,2012There are 2 redundant, independent power and scram channels. If the first scramchannel failed, the second channel would terminate the reactivity insertion at the samepower level, 1.09 MW(t). For this analysis, the 3 second period RWP is also ignored.There is a delay from the initiation of a scram to the insertion of a control rod of no morethan 0.5 seconds. This is the time necessary to close relay contacts, and (in the case ofa standard control rod) bleed the magnetic field from the rod drive magnetic coupling, andto bleed the air pressure (in the case of the transient rod drive.) The largest averageinsertion rate is the transient rod drive, 0.0997 $/sec. Starting at 1.0 MW(t), the reactorwould reach the LSSS of 1.09 MW, a scram would initiate, and the control rod is assumedto continue driving out for .5 seconds, resulting in an additional reactivity insertion of$0.05, which would produce a positive period of 210 seconds. At t+.5 seconds when theinsertion would be terminated and the rods all scrammed, the peak power would be1,092,598.33 watts. The maximum temperature would be 415.66 degrees C assumingthat peak power is reached immediately without delay before scramming the reactor.Similar analysis was performed for the remaining 3 control rods. (See table 2)Period and temperature were extrapolated from empirical data.
Table 1. (from original submitted document)Rod Total Total AverageWorth Withdrawal Insertion()Time (sec) Rate ($/sec)Transient 2.89 29 0.0997Safety 2.65 39.4 0.0673Shim 2.74 36.1 0.076Regulating 3.01 34.8 0.0865Table 2. Maximum power and temperature resultant from a ramp insertion frommaximum demand power assuming scram initiates .5 seconds after initiationRod $(0.5 Period(sec) P(0.5 sec) T(0.5sec) _________ sec)Tra nsie nt 0.0499 210 1,092,598.33 415.66Safety 0.0337 320 1,091,704.46 415.48Shim 0.0380 280 1,091,948.17 415.53Regulating 0.0433 230 1,092,372.14 415.60The 2nd column, $(0.5 sec), is the Average Insertion Rate ($Isec) from Table 1 multipliedby 0.5 seconds.The 3rd column, Period(sec), is the period in seconds from the In-Hour curve.The 4th column, P(0.5 sec), is the power in watts at 0.5 seconds from a 1.09 MW startpoint.The 5th column, T(0.5 sec), is the temperature in Celsius corresponding to the in the 4thcolumn.Figure 1. Temperature vs. power (hottest channel) fitted to a 5th order polynomialy = -AE-OS,,
- O.O381,~' -S1S29,~ = 111&4~- 1S930R'=O.9999po,(w)
- 2. The AFRRI proposed technical specifications (TS) 4.3, "Coolant Systems," Specificationa., states that "The pool water temperature, as measured near the input to the waterpurification system, shall be measured daily, whenever operations are planned.'1However, there is no requirement to calibrate the thermometer. Provide a TSsurveillance requirement for calibrating the temperature measurement instrument or statewhy it is not necessary.The periodicity of thermocouple and RTD probe calibration is located within themaintenance procedures. Currently, the TRIGA TRAKER requires calibration Annually,NTE 15 months.Temperature probes vary and the calibration frequency will vary based upon stability, thetype of probe, and the manufacturer's literature. The frequency required is listed clearlyin the maintenance TRIGA TRAKER and shall be performed as required. Compliancewith this requirement is inspected as an integral part of the NRC inspection program.3. The AFRRI proposed TS 4.3, "Coolant Systems," Specification b., states, in part, thatconductivity of the bulk water shall be measured monthly, not to exceed 6 weeks. Thebasis for this TS is "Based on experience, observation at these intervals providesacceptable surveillance of limits that ensure that fuel cladding corrosion and neutronactivation of dissolved materials are minimized."N UREG- 1537, Part 1, Appendix 14.1, Section 4.3, "Coolant Systems," Item (6)"Conductivity and pH," provides guidance that the conductivity and pH should bemeasured weekly. Monthly measurements are permitted if the reactor is shutdown forlong periods of time and/or if justification is provided in the SAR.The stability of conductivity within the AFRRI TRIGA pool water system has been provenby more than 5 decades of operations. Furthermore, experience demonstrates that theconductivity of the pool water not vary with reactor usage. Additionally, corrosion is anextremely slow process, making daily/weekly measurements unnecessary. NUREG-1537, Part 1, Appendix 14.1, Section 4.3, "Coolant Systems," Item (6) "Conductivity andpH," provides guidance that the conductivity and pH should be measured weekly.Monthly measurements are permitted if the reactor is shutdown for Iongq periods oftim.__e and/or if justification is provided in the SAR. Since conductivity is not a function ofusage, and NUREG-1537 permits monthly measurements, then it should be acceptableto make measurements on a monthly basis, whether or not operations are planned.4. NUREG-1537, Part 1, Appendix 14.1, Section 3.1, "Reactor Core Parameters," Item(6)(b), 'T'RIGA Fuel," provides guidance that the fuel matrix should not exceed 50 percentof its initial concentration. NUREG-1537, Part 1, Appendix 14.1, Section 4.1, "ReactorCore Parameters," Item (6), "Fuel Parameters," provides guidance that the SAR shouldjustify the surveillance method and intervals which ensure that the limit is not exceeded.Provide a TS and surveillance for burnup limit which is consistent with the guidance inNUREG-1 537, Part 1, or justify why no change is necessary.Tech Spec 3.7 e., FUEL PARAMETERS will be addede. The burnup of the uranium-235 in the UZrH fuel matrix shall not exceed 50 percent ofthe initial concentration.
The AERRI core contains 87+3 elements. The quantity of uranium 235 contained within astandard 8.5 weight percent TRIGA fuel element is known. From 1964 through 2016,AFRRI has logged approximately 42 MWD on the current core. Assuming 1gm of fuel isconsumed per MWD of operation, 42 grams of uranium 235 has been consumed.Assuming that the burn rate continues into the future, we will reach 50 percent burnup in2140 years.In addition, analysis shows that at approximately 80 MWD, excess reactivity will havediminished to the point where we will no longer be able to maintain power and will beforced to either recore or shut down, so that the issue of burnup is self-limiting.Table 4.8 From chapter 4 of the SAR demonstrates excess reactivity loss as a function ofburnup.AFRRI (85.3) DiF3D ARO Bumnup AnalysisIo 3 10 20 30 40 50 80 70 80 90 100WPD (Mwd)Fig~ure 4-8 The excmess vit as a function of buraup for 85-3 Core5. The AFRRI proposed TS 1.25 "Reference Core Condition," provides a value of $0.30 forXenon reactivity. Given that the reactivity required to satisfy the AERRI shutdown margin(SOM), TS 3.1.3, "Reactivity Limits," Specification b., is $0.50, in the Reference CoreCondition, the resulting SOM reactivity could be as bow as $0.20. This is not consistentwith the guidance in NUREG-1537, which provides a value of $0.50 SOM reactivity.Provide justification for proposed TS 1.25, "Reference Core Condition," by proposing aTS 3.1.3, "Reactivity Limits," Specification b., SOM reactivity limit that is consistent withthe SOM guidance in NUREG-1 537, revise TS 1.25 "Reference Core Condition," ordemonstrate that control rod worth can be determined by within $0.20.The definition of Reference Core Condition will be changed to read ... "worth of Xenon isnegligible (<$0.01 )."6. Your letter dated March 30, 2015 (ADAMS Accession No. ML15093A099), revising yourTS deleted TS 3.8, "ALARA." YourTS 6.1.2, "Responsibility," states "The RadiationSafety Officer shall rnplement a radiation protection program at AFRRI that satisfies the requirements of 10 CFR Part 20." Provide a justification for the deletion of TS 3.8.10CFR20 requires that every licensee maintain an ALARA program. 10CFR20requirements must be met regardless of the Technical Specifications, and also apply tothe other AFRRI licenses, making the citation in the TS redundant and superfluous.
- 7. AFRRI proposed TS. 3.3, "Coolant Systems," state the following: "The reactor shall notbe operated above a thermal power of 5 kW when the purification system inlet watertemperature exceeds 60°C;'" however, your thermal hydraulic analysis was performed at45°C. Provide a thermal hydraulic analysis at 60°C, or modify your TS to be consistentwith the thermal hydraulic analysis previously provided. Provide justification for the 5kWpower limit when water temperature is above 60°C or remove the limit from the TS.TS 3.3 will be modified to read "The reactor shall not be operated above a thermal powerof 5 kW when the core outlet temperature exceeds 60°C;'" The temperature rise acrossthe core at full power is approximately 15°C. This modification will ensure that water atthe core inlet will not exceed 45°C while the reactor is operating at 1.0 MW8. The AFFRI proposed TS 4.0, "Surveillance Requirements" states that "any surveillancerequirements that cannot be performed due to a reactor outage shall be performed priorto resuming normal reactor operations." Specify which requirements fall into this categoryor justify why it is not necessary.As the technical specifications state, no maintenance will be deferred unless an outageprevents maintenance from being performed. Since all possible equipment failures whichcould affect the reactor include items that have not yet occurred and yet more items thatare out of the reactor facility's control (i.e. power failure), a comprehensive and allinclusive list of all possible failures of equipment within and external to the facility is alsonot practical.We can list several examples of failures that could prevent completion of a maintenanceitem for example only; Console computer failure for example would prevent fuelmeasurement because we cannot monitor reactivity changes with the console down.Similarly, there are a myriad of calibrations that cannot be completed if the controlconsole (CSC or DAC) are not fully functional such as NM1000, NP, NPP, FuelTemperature, etc.Surveillance requirements are inspected during the normal inspection cycle andanomalies will be noted in the facility logs.9. ANSI/ANS 15.1-2007, Section 6.2.3, "Review Function," states "A written report orminutes of the [review] findings and recommendations of the review group shall besubmitted to Level 1 and the review and audit group members in a timely manner afterthe review has been completed." Your TS Section 6.2.4, "Review Function," does nothave such a requirement. Your Section 6.2.3.5, "Minutes," states that "Minutes of theprevious meeting should be available to regular members at least one week before aregular scheduled meeting," however, in TS 6.2.1.1 .a. 1, the Level 1 is not a regularmember. Explain the procedures by which the Level 1 is provided review findings in atimely manner.TS 6.2.3.5 will be modified to read:"a. Draft minutes of the previous meeting should be available to regular members at least one week before a regular scheduled meeting,""b. Once approved by the committee, final minutes will be submitted to level onemanagement for review."10. The AFFRI proposed TS 6.3, "Procedures," specifies, in part, "written instructions forcertain activities shall be approved by the Reactor Facility Director and reviewed by theRRFSS," but does not indicate if the procedures are required to be used and followed toensure effective procedure adherence. Revise TS 6.3 to include instructions for usingthese procedures or justify why no change is necessaryTS 6.3 shall be modified to read as follows:Original text:Written instructions for certain activities shall be approved by the Reactor Facility Directorand reviewed by the RRFSS. The procedures shall be adequate to ensure safe operationof the reactor, but shall not preclude the use of independent judgment and action asdeemed necessary. These activities are as follows:Modified text:Written instructions for certain activities shall be approved by the Reactor Facility Directorand reviewed by the RRFSS. The procedures shall be adequate to ensure safe operationof the reactor, but shall not preclude the use of independent judgment and action asdeemed necessary. Operating procedures shall be used for the following items:14. The AERRI proposed TS 6.4, "Review and Approval of Experiments," providesrequirements for new experiments or experiments not included in a Routine ReactorAuthorization. However, the TS does not include a review in accordance with TS 3.6,"Limitations on Experiments." Revise TS 6.4 to add the review requirements associatedwith TS 3.6, or justify why no changes are necessary.Current Text:Before issuance of a reactor authorization, new experiments shall be reviewed forradiological safety and approved by the following:a. Reactor Facility Directorb. Health Physics Departmentc. Reactor and Radiation Facilities Safety Subcommittee (RRFSS)
Prior to its performance, an experiment shall be included under one of the following typesof authorizations:a. Special Reactor Authorization for new experiments or experiments not included in aRoutine Reactor Authorization. These experiments shall be performed under the directsupervision of the Reactor Facility Director or designee.b. Routine Reactor Authorization for approved experiments safely performed at least once.These experiments may be performed at the discretion of the Reactor Facility Director andcoordinated with the Health Physics Department, when appropriate. These authorizationsdo not require additional RRFSS review.c. Reactor Parameters Authorization for routine measurements of reactor parameters,routine core measurements, instrumentation and calibration checks, maintenance,operator training, tours, testing to verify reactor outputs, and other reactor testingprocedures. This shall constitute a single authorization. These operations shall beperformed under the authorization of the Reactor Facility Director or the ReactorOperations Supervisor.Substantive (>$S0.25) changes to previously approved experiments shall be made only afterreview by the RRFSS and after approval (in writing) by the Reactor Facility Director ordesignated alternate. Minor changes that do not significantly alter the experiment (<$;0.25)may be approved by the Reactor Operations Supervisor. Approved experiments shall becarried out in accordance with established procedures.Revised Text:Before issuance of a reactor authorization, new experiments shall be reviewed forradiological safety and approved by the following:a. Reactor Facility Directorb. Health Physics Department
- c. Reactor and Radiation Facilities Safety Subcommittee (RRFSS)Prior to its performance, an experiment shall be included under one of the following typesof authorizations:a. Special Reactor Authorization for new experiments or experiments not included in aRoutine Reactor Authorization. These experiments shall be performed under the directsupervision of the Reactor Facility Director or designee.b. Routine Reactor Authorization for approved experiments safely performed at least once.These experiments may be performed at the discretion of the Reactor Facility Director andcoordinated with the Health Physics Department, when appropriate. These authorizationsdo not require additional RRFSS review.c. Reactor Parameters Authorization for routine measurements of reactor parameters,routine core measurements, instrumentation and calibration checks, maintenance,operator training, tours, testing to verify reactor outputs, and other reactor testingprocedures. This shall constitute a single authorization. These operations shall beperformed under the authorization of the Reactor Facility Director or the ReactorOperations Supervisor.Substantive (>$S0.25) changes to previously approved experiments shall be made only afterreview by the RRFSS and after approval (in writing) by the Reactor Facility Director ordesignated alternate to ensure that the change does not impact compliance with TS. 3.6,LIMITATIONS ON EXPERIMENTS. Minor changes that do not significantly alter theexperiment (<$0.25) may be approved by the Reactor Operations Supervisor. Approvedexperiments shall be carried out in accordance with established procedures.15. Pursuant to 10 CFR 50.33(f) (2), "[t]he applicant shall submit estimates for totalannual operating costs for each of the first five years of operations of the facility."Since the information included in the previous correspondence was for the period offiscal years (FYs) 2013 through 2018, please provide the following additionalinformation:
a) Projected operating costs of the AERRI facility for each of the FY20 16 thruFY2021 (the first five year period after the projected license renewal). If the costestimates have not changed since the previous submittal for the period ofFY201 3 through FY201 8, please so state.Cost estimates have not changed since the previous submittals for the period of FY20 13through FY2018b) Has the source(s) of funding to cover the operating costs for FYs 2016 to 2021changed since the August 13, 2010, submittal?The source of funding has not changed.16. By letter dated August 13, 2010, you provided an updated decommissioning costestimate for the facility that was developed using NUREG/CR-1 756, "Technology,Safety and Costs of Decommissioning Reference Nuclear Research and TestReactors." The decommissioning cost estimate was $14.831 million in 2011dollars. The cost estimate summarized costs by labor, radioactive wastesdisposal, energy, and a 25-percent contingency factor.(a) Please indicate if the basis for how the cost estimate was developedhas changed. I NUREG/CR-1 756 is still the basis, please so state.The basis for how the cost estimate was developed is still NUREG/CR-1 756(b) Please undicate i: there are any changes to the means of adjusting the costestimate and associated funding level periodically over the life of thefacility.There have been no changes to the means of adjusting the cost estimate and associatedfunding level over the life of the facility17. AFRRI provided a Statement of Intent (S~l), dated August 11,2010, stating that"[f]unding will be sought from the [U.S.] Department of Defense in accordance withestablished programming and budgeting procedures," per 10OCFR 50.75(e)(1)(iv).(a) Please indicate there have been any changes to the S~l and Idecommissioning funding obligations of the AFRRI facility continue to bebacked by the full faith and credit of the U.S. Government.There has been no change to the SQl. Decommissioning funding obligations of theAFRRI facility continue to be backed by the full faith and credit of the U.S. Government.