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Category:CORRESPONDENCE-LETTERS
MONTHYEARML20217D2841999-10-0404 October 1999 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program Covering Sept 1999 ML20211Q6361999-09-0303 September 1999 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program Covering Jul & Aug 1999 ML20211J4181999-08-30030 August 1999 Forwards Insp Rept 50-160/99-203 on 990119-21.No Violations Noted ML20210E9231999-07-22022 July 1999 Provides Responses to 990228 Comments on Georgia Tech Research Reactor Decommissioning Plan ML20210E9251999-07-22022 July 1999 Forwards Amend 14 to License R-97 & Safety Evaluation.Amend Authorizes Decommissioning of Gtrr,Per 10CFR50.82(b),IAW Decommissioning Plan,As Presented in 980701,990208 & 0528 Ltrs ML20210F3021999-07-22022 July 1999 Provides Responses to 990413 Comment on Georgia Tech Research Reactor Decommissioning Plan.Comment on Removal of Cobalt-60 Should Be Referred to State of Georgia ML20196K3381999-07-0202 July 1999 Forwards Copy of EA & Fonsi Related to Application for Amend Dated 980701.Proposed Amend Would Change Facility OL R-97, Authorizing Decommissioning IAW Proposed Decommissioning Plan ML20195C3531999-05-28028 May 1999 Forwards Environ Rept for Decommissioning of Ga Tech Research Reactor,Per NRC Regulation 51.53(d).Environ Rept Submitted in Apr 1994,encl ML20207A9581999-05-21021 May 1999 Ack Receipt of Re Comments on Georgia Tech Research Reactor Decommissioning Plan.Comments Will Be Considered as Part of NRC Ongoing Review of Decommissioning Plan ML20206R3061999-04-13013 April 1999 Submits Georgians Against Nuclear Energy Comments Re Intent of Georgia Tech to Decommission Neely Research Reactor at Georgia Inst of Technology,Atlanta,Ga ML20204G7561999-03-23023 March 1999 Ack Receipt of to Executive Director for Operations That Provided Comment on Georgia Tech Research Reactor Decommissioning Plan ML20204G7701999-02-28028 February 1999 Submits Comment on NRC Approval of Georgia Inst of Technology Decommissioning Plan for Their Neely Nuclear Research Reactor on Campus of Georgia Tech Pursuant to 10CFR20.1405 & 10CFR50.82(b)(5) ML20210P1381999-02-0808 February 1999 Forwards Response to NRC Request for Addl Info,Dtd 981228. Rev 0 to Quality Assurance Program Plan for Site Characterization of Georgia Tech Neely Nuclear Research Ctr Encl ML20202A8031999-01-25025 January 1999 Forwards Notice of Solicitation of Comments,Per 10CFR20.1405 & 10CFR50.82 (b)(5) for Proposed Action Concerning Decommissioning ML20202A8401999-01-25025 January 1999 Forwards Notice & Solicitation of Comments,Per 10CFR20.1405 & 10CFR50.82(b)(5) for Proposed Action Concerning Decommissioning ML20202A8691999-01-25025 January 1999 Forwards Notice of Solicitation of Comments,Per 10CFR20.1405 & 10CFR50.82(b)(5) for Proposed Action Concerning Decommissioning ML20198K8781998-12-28028 December 1998 Forwards Request for Addl Info Re Decommissioning Plan & License Termination Request for Facility License R-97 for Georgia Tech Research Reactor Submitted on 980701 ML20206P2481998-12-21021 December 1998 Expresses Appreciation for Opportunity to Comment Re Considered Issuance of Emergency Planning Exemption at Facility ML20197J3771998-12-10010 December 1998 Forwards Copy of Environ Assessment & Fonsi for Exemption from Emergency Plan Requirement of 10CFR50.54(q) for Georgia Inst of Technology Research Reactor.Exemption Granted ML20197J2801998-12-0404 December 1998 Responds to to NRC Commissioners Re Concerns That 980924 Response to Was Not from Commissioners. Weiss Response to Subj Ltr Reflects Positions & Policies Established by Commission ML20196H0821998-12-0303 December 1998 Forwards Environmental Assessment & Finding of No Significant Impact Re Licensee Application for Exemption from Emergency Planning Requirements of 10CFR50.54(q).Notice Indicates That NRC Considering Issuance of Exemption ML20155G9681998-11-0404 November 1998 Forwards Amend 13 to License R-97 & Safety Evaluation.Amend Removes Requirements for Security Plan to Protect Special Nuclear Matl Because License Does Not Allow Possession of SNM ML20154J8561998-10-0808 October 1998 Responds to Requesting Termination of Requalification Program for RO & Sro.Nrc Finds Request to Eliminate Operator Requalification Program Requirements Acceptable ML20154E3821998-10-0101 October 1998 Forwards bi-monthly Status Rept for Georgia Tech Research Reactor Decommissioning Program for Months of Aug & Sept 1998 ML20197J3061998-10-0101 October 1998 Submits Complain That Addressed to NRC Commissioners Was Answered by Someone Else in Different Section ML20154D7881998-10-0101 October 1998 Forwards Three Entries in Safeguards Event Log Made During Months of Jul,Aug & Sept 1998,per 10CFR73.71(a) Through (C) ML20153H2381998-09-24024 September 1998 Responds to on Concerns Related to Georgia Institute of Technology & Other Matters.Georgia Institute of Technology Submitted Decommissioning Plan by Ltr & Plan Currently Under Review by NRC Staff ML20153H2671998-08-27027 August 1998 Expresses Concern Re Georgia Institute of Technology Neely Nuclear Research Reactor,Contaminated Campus Area, Contaminated Reactor Bldg,Heavy Water & 200,000 Curies of Cobalt-60 Stored in Adjacent Bldg & in Pool ML20237E2461998-08-20020 August 1998 Requests NRC Approval of Exemption to Maintain Nnrc Emergency Preparedness Plan.Georgia Tech Was Defueled in Feb 1996 & All Nuclear Fuel Was Removed ML20237B6731998-08-10010 August 1998 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program for Month of Jul 1998 ML20236U4891998-07-21021 July 1998 Informs of Termination of Tritium Monitoring Activities Due to Requirement Specified in TS Tables 2.1 & 3.1 ML20236U4061998-07-15015 July 1998 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program for Month of June 1998 ML20236Q0671998-07-0101 July 1998 Requests Decommissioning Order for Ga Tech Research Reactor. Documentation Supporting Request,Listed.Reactor Is Currently in Safe Shutdown Condition & in Full Compliance W/Possession Only License.Page N-579 of Incoming Submittal Not Include ML20236J2561998-07-0101 July 1998 Informs That No Entries Were Made in Safeguards Event Log During Months of Apr,May & June 1998,per 10CFR73.71(a) Through (C) ML20236Q0731998-06-30030 June 1998 Issues Statement of Intent in Compliance w/10CFR50.75(e)(IV) Re State of Ga Support of Cost Estimate for Decommissioning of Ga Technology Research Reactor ML20236H5771998-06-18018 June 1998 Forwards Synopsis of NRC OI Completed Rept Re Alleged Discrimination by Georgia Institute of Technology Against Employee Who Filed Complaint W/Dol.Determined There Was Insufficient Evidence to Substantiate Allegation ML20154D6621998-06-0101 June 1998 Requests Termination of Requalification Program for Ros/Sros for License R-97.All Licenses for Ros/Sros Should Also Be Terminated.Fuel Has Been Removed from Facility & Licenses No Longer Needed ML20248J6711998-05-21021 May 1998 Forwards Monthly Status Rept for Ga Tech Research Reactor Decommissioning Program for Month of Apr 1998 ML20247K3591998-05-0707 May 1998 Forwards Insp Rept 50-160/98-201 on 980420-21.No Violations Noted.Various Aspects of Safety & Emergency Preparedness Programs Including Selective Exams of Procedures & Representative Records Were Inspected ML20217G2681998-04-20020 April 1998 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Month of Mar 1998 ML20217K6181998-04-0202 April 1998 Forwards Amend 12 to License R-97 & Se.Amend Removes Authority from License to Operate,Authorizes possession-only & Changes TS to Remove Operational Requirements of Reactor ML20202F4471998-02-0404 February 1998 Forwards Addl Info in Support of possession-only-license Amend Application Dtd 970807.Revised TS Re Rev to Facilitate Decommissioning,Encl ML20198H2661998-01-0202 January 1998 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Months of Nov & Dec 1997 ML20197J9891997-12-12012 December 1997 Responds to to Atlanta Ofc of EPA Re Georgia Tech Research Reactor.Nrc Evaluations Will Continue to Ensure Acceptable Application of Regulations to Protect Public Health & Safety,Including Decommissioning Activities ML20197G7441997-12-12012 December 1997 Forwards RAI Re Submittals for Possession Only License for Georgia Tech Research Reactor.Response Requested within 60 Days of Date of Ltr ML20197H3701997-12-12012 December 1997 Forwards Request for Addl Info Re Submittals for Possession Only License for Georgia Tech Research Reactor ML20199K8571997-11-24024 November 1997 Forwards Insp Rept 50-160/97-201 on 971027-31.No Violations Noted.Various Aspects of Operations,Safety & Security Programs Inspected Including Selective Exams of Procedures & Representative Records & Interviews W/Personnel ML20199G9971997-11-17017 November 1997 Forwards Ga Tech Research Reactor 1997 Emergency Preparedness Exercise Scenario.Exercise Scheduled for 971211 ML20202D1131997-11-13013 November 1997 Forwards Status Rept for Georgia Tech Research Reactor Deommissioning Program for Month of Oct 1997 ML20198T4371997-11-0606 November 1997 Submits Addl Info in Support of possession-only-license Amend & in Response to 970916 RAI 1999-09-03
[Table view] Category:INCOMING CORRESPONDENCE
MONTHYEARML20217D2841999-10-0404 October 1999 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program Covering Sept 1999 ML20211Q6361999-09-0303 September 1999 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program Covering Jul & Aug 1999 ML20195C3531999-05-28028 May 1999 Forwards Environ Rept for Decommissioning of Ga Tech Research Reactor,Per NRC Regulation 51.53(d).Environ Rept Submitted in Apr 1994,encl ML20206R3061999-04-13013 April 1999 Submits Georgians Against Nuclear Energy Comments Re Intent of Georgia Tech to Decommission Neely Research Reactor at Georgia Inst of Technology,Atlanta,Ga ML20204G7701999-02-28028 February 1999 Submits Comment on NRC Approval of Georgia Inst of Technology Decommissioning Plan for Their Neely Nuclear Research Reactor on Campus of Georgia Tech Pursuant to 10CFR20.1405 & 10CFR50.82(b)(5) ML20210P1381999-02-0808 February 1999 Forwards Response to NRC Request for Addl Info,Dtd 981228. Rev 0 to Quality Assurance Program Plan for Site Characterization of Georgia Tech Neely Nuclear Research Ctr Encl ML20206P2481998-12-21021 December 1998 Expresses Appreciation for Opportunity to Comment Re Considered Issuance of Emergency Planning Exemption at Facility ML20154E3821998-10-0101 October 1998 Forwards bi-monthly Status Rept for Georgia Tech Research Reactor Decommissioning Program for Months of Aug & Sept 1998 ML20154D7881998-10-0101 October 1998 Forwards Three Entries in Safeguards Event Log Made During Months of Jul,Aug & Sept 1998,per 10CFR73.71(a) Through (C) ML20197J3061998-10-0101 October 1998 Submits Complain That Addressed to NRC Commissioners Was Answered by Someone Else in Different Section ML20153H2671998-08-27027 August 1998 Expresses Concern Re Georgia Institute of Technology Neely Nuclear Research Reactor,Contaminated Campus Area, Contaminated Reactor Bldg,Heavy Water & 200,000 Curies of Cobalt-60 Stored in Adjacent Bldg & in Pool ML20237E2461998-08-20020 August 1998 Requests NRC Approval of Exemption to Maintain Nnrc Emergency Preparedness Plan.Georgia Tech Was Defueled in Feb 1996 & All Nuclear Fuel Was Removed ML20237B6731998-08-10010 August 1998 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program for Month of Jul 1998 ML20236U4891998-07-21021 July 1998 Informs of Termination of Tritium Monitoring Activities Due to Requirement Specified in TS Tables 2.1 & 3.1 ML20236U4061998-07-15015 July 1998 Forwards Status Rept for Georgia Tech Research Reactor Decommissioning Program for Month of June 1998 ML20236J2561998-07-0101 July 1998 Informs That No Entries Were Made in Safeguards Event Log During Months of Apr,May & June 1998,per 10CFR73.71(a) Through (C) ML20236Q0671998-07-0101 July 1998 Requests Decommissioning Order for Ga Tech Research Reactor. Documentation Supporting Request,Listed.Reactor Is Currently in Safe Shutdown Condition & in Full Compliance W/Possession Only License.Page N-579 of Incoming Submittal Not Include ML20236Q0731998-06-30030 June 1998 Issues Statement of Intent in Compliance w/10CFR50.75(e)(IV) Re State of Ga Support of Cost Estimate for Decommissioning of Ga Technology Research Reactor ML20154D6621998-06-0101 June 1998 Requests Termination of Requalification Program for Ros/Sros for License R-97.All Licenses for Ros/Sros Should Also Be Terminated.Fuel Has Been Removed from Facility & Licenses No Longer Needed ML20248J6711998-05-21021 May 1998 Forwards Monthly Status Rept for Ga Tech Research Reactor Decommissioning Program for Month of Apr 1998 ML20217G2681998-04-20020 April 1998 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Month of Mar 1998 ML20202F4471998-02-0404 February 1998 Forwards Addl Info in Support of possession-only-license Amend Application Dtd 970807.Revised TS Re Rev to Facilitate Decommissioning,Encl ML20198H2661998-01-0202 January 1998 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Months of Nov & Dec 1997 ML20199G9971997-11-17017 November 1997 Forwards Ga Tech Research Reactor 1997 Emergency Preparedness Exercise Scenario.Exercise Scheduled for 971211 ML20202D1131997-11-13013 November 1997 Forwards Status Rept for Georgia Tech Research Reactor Deommissioning Program for Month of Oct 1997 ML20198T4371997-11-0606 November 1997 Submits Addl Info in Support of possession-only-license Amend & in Response to 970916 RAI ML20198M7941997-10-14014 October 1997 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Month of Sept 1997 ML20211A7061997-09-12012 September 1997 Forwards Status Rept for Ga Tech Research Reactor Decommissioning Program for Month Aug 1997 ML20217J6211997-07-28028 July 1997 Provides Concerns Re 2.206 Director'S Decision & Ga Institute of Technology Neely Nuclear Research Reactor. Ltr for Docket as Well as 2.206 Docket Part & Svc List,Encl ML20217J8521997-07-28028 July 1997 Submits Info Re 2.206 Petition Under 10CFR20 Against Ga Institute of Technology Nuclear Research Reactor Located on Campus of Ga Tech in Middle of Downtown Atlanta ML20149K9341997-07-17017 July 1997 Forwards Entry in Safeguards Event Log Made During Month of April,May & June 1997,per 10CFR73.71(a)(c) ML20210L8901997-07-0707 July 1997 Forwards Rev 47 of Emergency Phone List.W/O Encl ML20141G2271997-06-30030 June 1997 Notifies NRC That on 970630,RA Karam Will Retire & Relinquish Directorship of Neely Nuclear Research Ctr,Ga Tech Research Reactor.N Hertel Will Be Appointed Director, Effective 970701 ML20137N9171997-04-0101 April 1997 Informs That No Entry in Safeguards Event Log Made During Jan,Feb & March 1997 ML20137B3031997-03-14014 March 1997 Submits Response to NRC Insp Rept 50-160/96-05.Corrective Actions:Licensees Promised to Develop Such Work Sheet & Put Into Practice on or Before 971201 ML20134L3061997-02-13013 February 1997 Responds to Notice of Exercise Weakness in Insp Rept 50-160/96-05.Corrective Actions:Will Conduct Emergency Drills & Will Conduct Addl Table Top Exercises ML20133F6441997-01-0808 January 1997 Informs That Pursuant to 10CFR73.71(a)(c),no Entry in Safeguards Event Log Made During Oct-Dec 1996 ML20134N0771996-11-18018 November 1996 Forwards Corrected Data Re Tritium Concentrations in Liquid Effluents for 1990-1995 ML20138G4271996-10-0808 October 1996 Informs That on 961126,licensee Planning to Hold Annual Emergency Drill.Attached Outline Gives Appropriate Details About Scenario ML20117J7791996-09-0202 September 1996 Requests Operator Licenses of Jn Copeland & Rv Demeglio Be Revoked ML20116B2561996-07-19019 July 1996 Informs NRC That Reactor Operators Kl Norton & Gm Comfort Have Left Ga Tech,Per 10CFR50.74.RO Licenses to Operate Gtrr Should Be Revoked ML20116A9671996-07-18018 July 1996 Responds to Violations Noted in Insp Rept 50-160/96-02. Corrective Actions:Conducted Meeting W/Radiation Safety Staff Re Regulatory Requirements & Replaced Retired Health Physicist Technician w/well-trained Health Physicist ML20137D4691996-06-27027 June 1996 Informs That B Statham Appointed Reactor Supervisor for Ga Tech Research Reactor,Effective Immediately ML20117K7521996-05-27027 May 1996 Requests NRC Assurance That Listed Documents Re 2.206 Petition Entered by Court Recorder Into Record.W/Certificate of Svc ML20117G2301996-05-13013 May 1996 Discusses Activities That Occurred at Neely Nuclear Research Ctr During Winter of 1995 & Lists Unsatisfactory Conditions Witnessed Re Facility Operations.Related Correspondence ML20108E6461996-05-0808 May 1996 Notifies Honorable Judges Bechhoefer,Kline & Lam of ASLB, That P Blockey-O'Brien Will Present Testimony of Min of 30 Minutes on 960522,including But Not Limited to Listed Info. W/Certificate of Svc.Served on 960510 ML20101D6271996-03-14014 March 1996 Discusses 10CFR2.206 Petition & New Info on Earthquake Risk, Possible Unsafe Conditions Developed Due to Site If Ga Tech Neely Reactor & Problems ML20097E6181996-02-0707 February 1996 Submits Notice of Shipment of Nuclear Matl from Atlanta,Ga to DOE in Aiken,Sc ML20097D8181996-01-27027 January 1996 Discusses 10CFR2.206 Petition Against Georgia Tech Reactor on Campus in Atlanta,Possible License Problems & Contamination Problems.W/Certificate of Svc.Served on 960205 ML20096D0151996-01-10010 January 1996 Discusses P Blockey-O'Brien 10CFR2.206 Petition & Ltrs Written to NRC & ASLB Judges Re Petition & Georgia Tech Neely Nuclear Research Reactor,Radioactive Contamination, Violations & ALARA Issue 1999-09-03
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}j NEELY NUCLEAR RESEARCH CENTER (L s.,~,' - 900 ATLANTIC DRIVE 6, ' ""' ' 8 ATLANTA, GEORGIA 30332-0425 USA (4o4) 094 MOO July 15, 1994 Mr. Marvin M. Mendonca, Senior Project Manager Non-Power Reactors and Decommissioning Project Directorate Division of Operating Reactor Support Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001
Dear Mr. Mendonca:
This is in response to your letter of May 17, 1994 concerning the conversion of the GTRR from high-to-low-enriched fuel. The answers to your questions were provided for the most part by Dr.
William Woodruff and Dr. James Matos of Argonne National Laboratory. With your consent, this response was delayed in order to have in hand Argonne's complete response.
Question 1.
Specification 2.1.1, Safety Limits in the Forced Convection Mode
- a. Specification 2.1.1.a refers to Figure II-1, for which you have provided a revised version II-1 (new) to replace the existing II-I (old).
- 1. Because the line for HEU will no longer be applicable after the reactor is converted to LEU, the HEU line from Fig. II-l (new) should be eliminated to avoid confusion.
- 2. The remaining line for LEU (flow instability) should represent the acceptable safety limit envelope of the converted Georgia Tech Research Reactor, so it seems appropriate to ink that plot in solid, instead of dashed lines.
Provide these changes or rationale as to why they are not needed.
l Response A revised Figure II-1 is attached
- b. Specification 2.1.1, Basis, discusses departure from nucleate boiling (DNB) initially and then later discusses DNB and flow instability criteria. While mention of depar,ture from nucleate boiling is acceptable, emphasis shoul.dj.be clearly placed on initiation of flow 9407250005 940715 PDR ADDCK 05000160 hbl ,
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A Unit of the Uravers:ty System of Georgo An Equal Educean and Emetoymem Occoqumtv instNt.on
s Mr. Marvin M. Mendones
- July 15, 1994 Page 2 instability as the limiting critaria, since it is limiting. Provide changes that clarify this issue.
Response: The first sentence -
" Gross fuel element failure and concomitant fission produce release will not occur unless there is departuro from nucleate boiling." Should be replaced with the following -
" Gross fuel element failure and concomitant fission product release will not occur until after there is onset of flow instability."
- 2. Specification 2.2.1, Limiting Safety System Settings in the Forced Convection Mode, Basis, uses the phrase "with no incipient boiling." For internal consistency in your T.S.,
the same phrases should be used wherever appropriate. If
" incipient boiling" is inferred from either " departure fron nucleate boiling" or " initiation of flow instability" calculatiens, use only the term that applies. If they are not interchangeable, please provide a reference as to your analyses that support this different usage or an explanation of the difference in the basis.
hesponse: Replace the-use of " incipient boiling" with " onset of nucleate boiling".
- 3. Specification 5.2, Fuel Elements; provide changes to this specification to accommodate the conversion to LEU fuel. .
Tho LEU fuel elements shall be of the MTR type consisting of 18 fuel plates of uranium silicide with an enrichment less than 20%. Each fuel plate will have a nominal loading of 12.5 grams of U-235. The HEU fuel elements shall also be of the MTR type consisting of 16 fuel plates of uranium aluminide with an enrichment of 93%. Each fuel plate will have nominal loading of 11.75 grams of U-235.
- 4. Provide a description of how the PARET code uses boundary conditions for inlet and outlet of the flow channels (e.g.,
pressure or flow, or can either be specified). Explain what boundary conditions are used for the transient analyses.
Response PARET can be provided with either an inlet flow I rate per unit area or a pressure drop as boundary l conditions. Since the flow for the reactor is specified, tnis value was used for these transient analyses.
l l
Mr. Marvin M. Mendonca July 15, 1994 Page 3
- 5. Describe the PARET heat transfer modeling from channel to channel (e.g., heat transfer from the hot to average channels).
Response: The PARET code does not model channel to channel heat transfer. Since plate type fuel has closed channels there is no cross flow, and conduction through the side plates would be negligible for most transients. This is a conservative model.
- 6. Describe how the PARET subcooled boiling model has been benchmarked against any separate effects test, such as the Christensen, Marchaterre, or the Shoukri data. Describe the results of the benchmarking.
Response: The PARET code has been bemhmarked against the "subcooled" SPERT experimental transient data for plate type fuel: See - William L. Woodruff, "A Kinetics and Thermal-hydraulics Capability for the Analysis of Research Reactors, " Nucl. Technol. , 64, pp. 199-202, 1984 and W. L. Woodruff, " Additional Capabilities and Benchmarking with the SPERT Transients for Heavy Water Applications of the PARET Code," Proc. XIIth International Meeting on Reduced Enrichment for Research and Test Reactors, Berlin, 10-14 Sept 1989, pp. 357-365, Konferenzen des Forschungs-zentrums Julich (1991).
- 7. Describe how the PARET code flow instability model has been benchmarked against rny experiments. Were the comparisons for upflou and downf?k Describe the results of the benchmarking. Desci @ any nodalization studies that were performed to verity the effects of modeling on flow instability.
Response: A flow instability model has not been incorporated into the PARET code. Instead, the code estimates the eta parameter as a function of time for use with the Whittle and Forgan correlation for flow instability. See the steady-state analyses in IAEA-TECDOC-233, pp.99-106 (1980). The estimate of eta was found to be insensitive to the node selaction.
- 8. Describe how PARET models the " dynamic" pressure. Is it based on the average channel flow from tne point where the boundary pressure is known using the momentum equation? Have any calculations been performed to assess the local pressure to a thermodynamic " state" pressure for two-phase flow?
i Mr. Marvin M. Mendonca July 15, 1994 Page 4 Response The PARET code has a single fluid, incompressible thermal-hydraulics model based on a modified momentum integrated model (channel averaged mass flow and coolant properties based on a reference pressure). Only the coolant density is evaluated as a function of local pressure. Given an inlet pressure, the local pressure is determined based on friction, elevation, and spatial and transient acceleration. See - C. F. Obenchain, "PARET -A Program for the Analysis of Reactor Transients,"
IDO-17282, Idaho National Engineering Laboratory (1969).
- 9. Describe how PARET models void propagation applied to downflow conditions. Include discussion of the modeling of void propagation when boiling will most likely take place at the exist of the channel and can result in flow reversal.
Response: The GTRR has upflow, and the reactor was modeled with upflow. PARET can model downflow conditions, and it can model flow reversal with loss-of-flow from a forced downflow condition to an upflow condition with natural convection (See R. S. Smith and W. L. Woodruff, " Thermal-hydraulic Aspects of Flow Inversion in a Research Reactor," Proc. 1986 International Meeting on Reduced Enrichment for Research and Test Reactors, 3-6 Nov, 1986, ANL/RERTR/TM-9, CONF-861185, pp. 449-460 (May 1988).
- 10. Describe the rate of void production when using the Bergles-Rohsenow criteria for subcooled boiling in the PARET code. Is the void propagation model used in subcooled boiling?
Response: The Bergles-Rohsenow correlation is used in PARET as both a trigger for ONB and for part of a transition model to fully developed nucleate boiling. The void production model includes subcooled boiling and distinguishes between the boiling regimes of nucleate boiling, transition boiling and film boiling (independent of the correlation used for subcooled boiling). The voiding model is described in the PARET manual - C.
F. Obenchain, "PARET - A Program for the Analysis of Reactor Transients," IDO-17282, Idaho National Engineering Laboratory (1969).
- 11. Described how the PARET code models the heated wall viscosity effects. Include discussion of the treatment of the viscosity decrease near the wall of a heated fuel plate. Describe how
f' .
j;
3- Mr. Marvin M. Mendonca July 15, 1994 Page 5 the decrease in friction is modeled. Include the description of the treatment of single phase friction or two-phase conditions.
Response: The PARET code includes the Sieder-Tate correlation option, which has a surface temperature dependent viscosity. The single and two-phase friction treatment is as described in the original PARET manual - C. F. Obenchain, "PARET - A Program for the Analysis of Reactor Transients," IDO-17282, Idaho National Engineering Laboratory (1969).
- 12. Describe how PARET calculates the average channal flow. Is it equivalent to the imposition of an inlet pressure and an outlet pressure, and iteration for the friction loss and associated new time flow? Describe how the calculational approach precludes any local flow reversal within the channel if the average channel flow is calculated from the imposed pressures at the inlet and ouP.let.
Response PARET uses either a fixed input flow or a fixed pressure drop that does not change with time (See responses #4 and #8). The GTRR is upflow, and flow reversal is not a consideration.
- 13. For other recent LEU conversion analyses - (e.g. , Rhode Island) the modeling may have been different than used in that of Georgia Tech. The following questions are to better ;
understand the potential modeling differences and effects.
l
- a. It is understood that the Whittle and Forgan flow instability model was recently instituted for use in the PARET code. When was that done? Is it an automatic.
option in the PARET code? For other recent LEU conversions, was this model used? Discuss the accuracy i of the model and comparison to other flow instability 1 models that have been used or are available in PARET. I Response: See response #7. The PLTEMP code (not the PARET code) was used for the steady-state data that was quoted for the Georgia tech reactor. The Whittle and Forgan correlation was included in the early 1980s. The modeling for the Georgia Tech reactor is consistent with the GTRR design. In other reactors the applicable design conditions were also modeled.
- b. Describe the PARET modeling for heat transfer to the side {
plates. Was this function nodeled in other recent LEU i conversion analyses? Provide a comparison of this l 1
l
a l
l 1
Mr. Marvin M. Mendonca July 15, 1994 Page 6 modeling and assumptions for the different PARET applications.
Response PARET has a 1-D heat transfer model (See also response #5). By neglecting transverse heat transfer to the side plates, the model will give conservative estimates for all applications.
- c. Describe how tha channel tolerances were modeled in the PARET code. Was this function modeled in other recent LEU conversion analyses? Provide a comparison of this modeling and assumptions for the different PARET applications.
Response: Channel uncertainties are modeled only in the PLTEMP analyses for st<aly-state margins. A peaking factor is applir to the hot channel in PARET as predicted by the neutronics computations.
The basis in PARET is to always provide an estimate for the transient behavior of each reactor under nominal conditions with conservative models and consistent with the SPERT experiments (see response
- 6).
- d. Describe the modeling of the bypass flow in the PARET modeling and comparison to other recent LEU conversion analyses. What was the bypass percentage of total flow?
Response PARET uses the flow that is provided to the active core in proportion to the channel modeled. No bypass flow was modeled in the GTRR case. The reference flow rates as described in the safety documentation were used.
- e. Provide a comparison of radial and axial peaking factors used in the PAR 3T code with other recent LEU conversions.
Response: The radial and axial nuclear power peaking factors that were used in the computations for the Georgia Tech heavy water reactor are provided in Figure 8 and 9 in Attachment 2, Table 2-1 of the ANL report
" Analyses for Conversion of the Georgia Tech Research Reactor from HEU to LEU Fuel,' J. E.
Matos, S. C. Mo, and W. L. Woodruff, September 1992. These factors for the Rhode Island light water reactor are ycovided in Table 3, p. 14, of the Rhode Island Atomic Energy Commission Report
" Safety analysis Report for the Low Enrichment Fuel Conversion of the Rhode Island Nuclear Science Center Research Reactor," November 1991.
l Mr. Marvin M. Mendonca l July 15, 1994 l Page 7 l
- 14. Describe how the fuel plate heat transfer area is calculated.
Is the area based on the width of the plate or the active-j fuel?
Response: The heat transfer area is based on the nominal height and width of the active fuel.
Should you have additional questions, please let me know.
. Sincerely, bM ~ GhA.U -
R.A. Karam, Ph.D., Director Neely Nuclear Research Center-I RAK/ccg i i
i l
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l
.1 i
J J
t l
l
- l I
t Fig.11 - 1. GTRR Safety Limit for Forced Convection 16 -
BASES: Moderator Within 12 Inchos of Overflow
- Tin = 123*F Man When the Flow is Minimized ~ ~ ~ ~ ' ~ ~ ~ ~-
3: 14 ---~-g PowerTs'~M axit iiie~d~ - - ~ ~ ~ - ~ ~ ~ ~ ~ ~ ~ -
E 3g . - . - - - - - - - _ _ - . . - . - _.- -- -
"O 10 - - - - - --- - - -
Flow Instability \
% Line: ANL LEU SAFETY LIMIT BOUNDARY E 8 - - - - -
w \
$ Mode 2 H 6 - - - - - - - - - - - - - - - - -
Nominal Operating O Conditions, Tin = 114 F o
%n 4 - - - - - - - -
E 2 - - - - - - -- - - - - - - - - - - - - - - - -Model Nominal Operating 0 Conditions, Tin = 114'F 0 ,
500 1000 1500 2000 2500 Reactor Coolant Flow (GPM)
I 1