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Category:CORRESPONDENCE-LETTERS
MONTHYEARML20205G8771999-03-26026 March 1999 Forwards Copy of Cover Page from Fort St-Vrain Welding Manual,Which Had Been Listed as Encl on Page 4 of 990325 Reply to EA 98-081.Cover Page Had Been Inadvertently Left Out with Original Reply ML20197H8811998-12-0101 December 1998 Forwards Proposed Change to Fsv ISFSI Physical Protection Plan in Which Commitment Is Made to Provide Feature to Security Posture for Facility ML20236R9191998-07-20020 July 1998 Ltr Contract:Mod 4 to Task Order 27, Task Area No 4 of Basic Contract - Fort St Vrain Insp Under Contract NRC-02-95-003 ML20199H8141997-11-21021 November 1997 Responds to Requesting Clarification as to Whether Increase in Tritium & Iron-55 Contamination Limits That Were Approved for Plant Apply to All Licensees ML20198K1931997-10-10010 October 1997 Provides Supplemental Info in Support of Util Proposed Rev to Physical Security Plan for Plant Plant Isfsi.Plan Withheld,Per 10CFR2.790(d) & 10CFR73.21 ML20198H5601997-09-16016 September 1997 Final Response to FOIA Request for Documents.Documents Listed in App a Being Released in Entirety ML20141F3521997-05-14014 May 1997 Forwards Proposed Issue 4 of Physical Security Plan for Fort St Vrain ISFSI for Review & Approval.Encl Withheld,Per 10CFR2.790(d) ML20141C8611997-05-0909 May 1997 Informs of Approval of Fsv Final Survey Rept & Effluent Pathway Survey Plan & Supporting Analysis ML20141K9881997-05-0505 May 1997 Forwards Amend 89 to License DPR-34 & Supporting Safety Evaluation.Amend Designates All Elements of Approved Decommissioning Plan as License Termination Plan ML20138G2701997-04-28028 April 1997 Provides Response to NRC Comments Re Proposed Sampling & Survey Plan for Fsv Effluent Pathway.Response Documents Fsv Liquid Effluent Discharge Pathway Areas Are Acceptable for Release for Unrestricted Use IAW Draft NUREG/CR-5849 ML20148D4651997-04-24024 April 1997 Forwards Revised Interim Ltr Rept Which Describes Procedures & Results of Confirmatory Survey of Group E Effluent Discharge Pathway Areas at Fsv Station NUREG/CR-5849, Requests That Licensee Provide Evidence That Average Contamination Levels in Group E Effluent Discharge Pathway Areas Meet Averaging Criteria in Draft NUREG/CR-58491997-04-23023 April 1997 Requests That Licensee Provide Evidence That Average Contamination Levels in Group E Effluent Discharge Pathway Areas Meet Averaging Criteria in Draft NUREG/CR-5849 ML20138B0511997-04-22022 April 1997 Forwards Copy of Proposed Amend to Fsv NPDES Permit, Wastewater Discharge Permit CO-0001121 Requested to Support Repowering Activities,Iaw Section 3.2.d of Fsv Non-Radiological Ts,App B to License DPR-34 ML20140E1061997-04-10010 April 1997 Forwards Confirmatory Survey of Group Effluent Discharge Pathway Areas for Fsv Nuclear Station,Platteville,Co ML20137S4481997-04-0808 April 1997 Informs That Decommissioning Activities at Fsv Are Complete & NRC Issued Exemption from Requirements of 10CFR50.54(w) in .Property Damage Insurance Policy Is Maintaned to Protect Fsv balance-of-plant Assets ML20137S0821997-04-0707 April 1997 Forwards Insp Rept 50-267/97-01 on 970310-11.No Violations Noted ML20137S1691997-04-0707 April 1997 Fifth Partial Response to FOIA Request for Documents. Forwards Documents Listed in App K ML20137S5421997-04-0707 April 1997 Forwards Final Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments Affecting Decommissioning of Fort St Vrain Nuclear Station ML20148D5951997-04-0404 April 1997 Forwards Confirmatory Survey for Fsv Nuclear Station, Psc,Platteville,Co, Final Rept ML20137R6921997-04-0404 April 1997 Informs of Approval for Request for Addl 45 Days to Remedy Deficiencies Identified in NRC Re Financial Assurance Mechanism for Fsv Decommissioning Costs ML20137J8051997-03-31031 March 1997 Third Partial Response to FOIA Request for Documents.Records in App F Encl & Will Be Available in Pdr.App G & H Records Withheld in Part (Ref FOIA Exemptions 5 & 7) ML20148D5811997-03-26026 March 1997 Forwards Confirmatory Survey Plan for Group E Effluent Discharge Pathway Areas at Fsv Nuclear Station, Covered in Final Survey Rept,Vol 6 ML20137G7361997-03-25025 March 1997 Requests Addl Time for Util to Respond to NRC Comments in Re Financial Assurance Mechanism for Fort St Vrain Decommissioning Costs ML20137G9521997-03-24024 March 1997 Forwards Quarterly 10CFR50.59 Rept for Period 961201-970228 Re Changes,Tests & Experiments for Fort St Vrain Decommissioning ML20137H1131997-03-24024 March 1997 Second Partial Response to FOIA Request for Documents. Forwards Documents Listed in App D.Documents Also Available in Pdr.Documents Listed in App E Withheld in Part (Ref FOIA Exemption 6) ML20137C0181997-03-18018 March 1997 Documents That No Personnel Has Received Radiation Exposure at Fsv in 1997 or at Any Time Subsequent to ML20137C0061997-03-18018 March 1997 Documents That There Have Been No Activities Involving Release of Radioactive Matls from Fsv Nuclear Station That Potentially Could Have Affected Environ,Subsequent to Previous Radiological Envion Operating Rept ML20136G1201997-03-11011 March 1997 Forwards Annual Radioactive Effluent Release Rept for Jan- Dec 1996 & Jan-Mar 1997. All Effluent Releases Completed as of 960703.Repts on Activities After 960703 Reflect Disposal of Solid Waste ML20136B1331997-02-28028 February 1997 First Partial Response to FOIA Request for Documents. Documents Listed in App a Already Available in Pdr.Forwards App B Documents.App C Documents Being Withheld in Entirety (Ref FOIA Exemption 5) ML20135D7891997-02-27027 February 1997 Forwards Responses to Comments Re Fort St Vrain Final Survey Rept ML20135D9531997-02-27027 February 1997 Forwards Copy of Amend to Util Npdes,Wastewater Discharge Permit CO-0001121,which Clarifies That Monitoring of Farm Pond Outlet Required When Industrial Wastewater Being Discharged Through Upstream Goosequill Ditch ML20135A8711997-02-14014 February 1997 Requests That Encl Deficiencies Identified in Financial Assurance Mechanism for Fort St Vrain Decommissioning Cost Be Addressed within 45 Days ML20134D1551997-01-31031 January 1997 Forwards Util Responses to NRC Comments Provided in NRC Ltr Re Sampling & Survey Plan Used for Final Radiological Survey of Liquid Effluent Pathway at Ft St Vrain ML20134C8481997-01-30030 January 1997 Forwards Draft Confirmatory Survey Rept for Fsv Nuclear Station,Psc,Platteville,Co Providing Info on Essap Activities on 960930-1003 ML20133L4961997-01-0707 January 1997 Forwards Comments That Need to Be Resolved Before Final Approval of Util Submittal Entitled, Proposed Sampling & Survey Plan for Effluent Pathway,Ft St Vrain Final Survey Program ML20133E0481997-01-0202 January 1997 Forwards Comments to Fsv Nuclear Station, Decommissioning Project Final Survey Rept (Volumes 4-11), for Consideration ML20132G0421996-12-23023 December 1996 Forwards Insp Rept 50-267/96-05 on 961203-05.No Violations Noted ML20132F2841996-12-19019 December 1996 Forwards Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments Affecting Decommissioning of Plant,Covering Period of 960901-1130 ML20133A8591996-12-16016 December 1996 Forwards Original & Copy Transcripts of Public Hearing,Held on 961203 in Platteville,Co Re Decommissioning & License Termination of Util Ft Saint Vrain Nuclear Generating Station ML20133N0011996-12-0404 December 1996 Recommends That NRC Require License to Modify Submission of Unexecuted Draft Trust Agreement Remaining Decommissioning Costs for Ft St Vrain Nuclear Generating Station in Listed Ways ML20135B3861996-11-25025 November 1996 Informs That NRC Reviewed Util 961114 Submittal (P-96096) Entitled, Fort St Vrain Final Emergency Response Plan, & Meets Requirements of 10CFR50.54(q) ML20135A5861996-11-25025 November 1996 Submits Suppl Info Re Annual Environ Rept for 1995 Operation of Fsv ISFSI ML20135A6361996-11-20020 November 1996 Submits Copy of Describing Discharge Practices for Groundwater Seeping Into Fsv'S Reactor Building Sump ML20134L4721996-11-14014 November 1996 Notifies NRC That Util Adopted Fsv ISFSI Emergency Response Plan to Direct Emergency Response for Radiological Accidents Occuring at Site,Until 10CFR50 License Is Terminated ML20134F4351996-10-30030 October 1996 Forwards Sections 1,2,6 & 8 from Survey Packages F0015, F0039 & F0126 & Sections 1,2 & 6 from Survey Package F0115 to Support on-site NRC Insp ML20134G5991996-10-30030 October 1996 Forwards Volumes 1-12 to Final Survey Rept for Groups A,B,C Rev 1,D Rev 1,E,F Rev 1 & G-J for NRC Approval in Support of Forthcoming Request for Termination of Fsv 10CFR50 License ML20133D7691996-10-22022 October 1996 Forwards Preliminary Rept Re Orise Support of NRC License Insp at Fsv on 960930-1003 ML20136B1411996-10-15015 October 1996 FOIA Request for Documents Re NOV Addressed to Scientific Ecology Group Re NRC Insp Rept 50-267/94-03 & OI Investigation Repts 4-94-010 & 4-95-015 ML20128M6181996-10-0404 October 1996 Forwards Ltr from PSC to Co Dept of Public Health & Environ Describing Monitoring Practices at Plant ML20128G8041996-10-0101 October 1996 Forwards Fsv Decommissioning Fire Protection Plan Update 1999-03-26
[Table view] Category:INCOMING CORRESPONDENCE
MONTHYEARML20205G8771999-03-26026 March 1999 Forwards Copy of Cover Page from Fort St-Vrain Welding Manual,Which Had Been Listed as Encl on Page 4 of 990325 Reply to EA 98-081.Cover Page Had Been Inadvertently Left Out with Original Reply ML20197H8811998-12-0101 December 1998 Forwards Proposed Change to Fsv ISFSI Physical Protection Plan in Which Commitment Is Made to Provide Feature to Security Posture for Facility ML20198K1931997-10-10010 October 1997 Provides Supplemental Info in Support of Util Proposed Rev to Physical Security Plan for Plant Plant Isfsi.Plan Withheld,Per 10CFR2.790(d) & 10CFR73.21 ML20141F3521997-05-14014 May 1997 Forwards Proposed Issue 4 of Physical Security Plan for Fort St Vrain ISFSI for Review & Approval.Encl Withheld,Per 10CFR2.790(d) ML20138G2701997-04-28028 April 1997 Provides Response to NRC Comments Re Proposed Sampling & Survey Plan for Fsv Effluent Pathway.Response Documents Fsv Liquid Effluent Discharge Pathway Areas Are Acceptable for Release for Unrestricted Use IAW Draft NUREG/CR-5849 ML20148D4651997-04-24024 April 1997 Forwards Revised Interim Ltr Rept Which Describes Procedures & Results of Confirmatory Survey of Group E Effluent Discharge Pathway Areas at Fsv Station ML20138B0511997-04-22022 April 1997 Forwards Copy of Proposed Amend to Fsv NPDES Permit, Wastewater Discharge Permit CO-0001121 Requested to Support Repowering Activities,Iaw Section 3.2.d of Fsv Non-Radiological Ts,App B to License DPR-34 ML20140E1061997-04-10010 April 1997 Forwards Confirmatory Survey of Group Effluent Discharge Pathway Areas for Fsv Nuclear Station,Platteville,Co ML20137S4481997-04-0808 April 1997 Informs That Decommissioning Activities at Fsv Are Complete & NRC Issued Exemption from Requirements of 10CFR50.54(w) in .Property Damage Insurance Policy Is Maintaned to Protect Fsv balance-of-plant Assets ML20137S5421997-04-0707 April 1997 Forwards Final Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments Affecting Decommissioning of Fort St Vrain Nuclear Station ML20148D5951997-04-0404 April 1997 Forwards Confirmatory Survey for Fsv Nuclear Station, Psc,Platteville,Co, Final Rept ML20148D5811997-03-26026 March 1997 Forwards Confirmatory Survey Plan for Group E Effluent Discharge Pathway Areas at Fsv Nuclear Station, Covered in Final Survey Rept,Vol 6 ML20137G7361997-03-25025 March 1997 Requests Addl Time for Util to Respond to NRC Comments in Re Financial Assurance Mechanism for Fort St Vrain Decommissioning Costs ML20137G9521997-03-24024 March 1997 Forwards Quarterly 10CFR50.59 Rept for Period 961201-970228 Re Changes,Tests & Experiments for Fort St Vrain Decommissioning ML20137C0061997-03-18018 March 1997 Documents That There Have Been No Activities Involving Release of Radioactive Matls from Fsv Nuclear Station That Potentially Could Have Affected Environ,Subsequent to Previous Radiological Envion Operating Rept ML20137C0181997-03-18018 March 1997 Documents That No Personnel Has Received Radiation Exposure at Fsv in 1997 or at Any Time Subsequent to ML20136G1201997-03-11011 March 1997 Forwards Annual Radioactive Effluent Release Rept for Jan- Dec 1996 & Jan-Mar 1997. All Effluent Releases Completed as of 960703.Repts on Activities After 960703 Reflect Disposal of Solid Waste ML20135D7891997-02-27027 February 1997 Forwards Responses to Comments Re Fort St Vrain Final Survey Rept ML20135D9531997-02-27027 February 1997 Forwards Copy of Amend to Util Npdes,Wastewater Discharge Permit CO-0001121,which Clarifies That Monitoring of Farm Pond Outlet Required When Industrial Wastewater Being Discharged Through Upstream Goosequill Ditch ML20134D1551997-01-31031 January 1997 Forwards Util Responses to NRC Comments Provided in NRC Ltr Re Sampling & Survey Plan Used for Final Radiological Survey of Liquid Effluent Pathway at Ft St Vrain ML20134C8481997-01-30030 January 1997 Forwards Draft Confirmatory Survey Rept for Fsv Nuclear Station,Psc,Platteville,Co Providing Info on Essap Activities on 960930-1003 ML20133E0481997-01-0202 January 1997 Forwards Comments to Fsv Nuclear Station, Decommissioning Project Final Survey Rept (Volumes 4-11), for Consideration ML20132F2841996-12-19019 December 1996 Forwards Quarterly 10CFR50.59 Rept of Changes,Tests & Experiments Affecting Decommissioning of Plant,Covering Period of 960901-1130 ML20133A8591996-12-16016 December 1996 Forwards Original & Copy Transcripts of Public Hearing,Held on 961203 in Platteville,Co Re Decommissioning & License Termination of Util Ft Saint Vrain Nuclear Generating Station ML20133N0011996-12-0404 December 1996 Recommends That NRC Require License to Modify Submission of Unexecuted Draft Trust Agreement Remaining Decommissioning Costs for Ft St Vrain Nuclear Generating Station in Listed Ways ML20135A5861996-11-25025 November 1996 Submits Suppl Info Re Annual Environ Rept for 1995 Operation of Fsv ISFSI ML20135A6361996-11-20020 November 1996 Submits Copy of Describing Discharge Practices for Groundwater Seeping Into Fsv'S Reactor Building Sump ML20134L4721996-11-14014 November 1996 Notifies NRC That Util Adopted Fsv ISFSI Emergency Response Plan to Direct Emergency Response for Radiological Accidents Occuring at Site,Until 10CFR50 License Is Terminated ML20134F4351996-10-30030 October 1996 Forwards Sections 1,2,6 & 8 from Survey Packages F0015, F0039 & F0126 & Sections 1,2 & 6 from Survey Package F0115 to Support on-site NRC Insp ML20134G5991996-10-30030 October 1996 Forwards Volumes 1-12 to Final Survey Rept for Groups A,B,C Rev 1,D Rev 1,E,F Rev 1 & G-J for NRC Approval in Support of Forthcoming Request for Termination of Fsv 10CFR50 License ML20133D7691996-10-22022 October 1996 Forwards Preliminary Rept Re Orise Support of NRC License Insp at Fsv on 960930-1003 ML20136B1411996-10-15015 October 1996 FOIA Request for Documents Re NOV Addressed to Scientific Ecology Group Re NRC Insp Rept 50-267/94-03 & OI Investigation Repts 4-94-010 & 4-95-015 ML20128M6181996-10-0404 October 1996 Forwards Ltr from PSC to Co Dept of Public Health & Environ Describing Monitoring Practices at Plant ML20128G8041996-10-0101 October 1996 Forwards Fsv Decommissioning Fire Protection Plan Update ML20128G0481996-09-30030 September 1996 Submits Rev to Psco Definitions of Contents of Documentation Packages Re Fsv Final Survey Project ML20129C0421996-09-20020 September 1996 Forwards Quarterly Submittal of 10CFR50.59 Rept of Changes, Tests & Experiments for Facility Decommissioning,Covering Period of 960601-0831 ML20133D7601996-09-16016 September 1996 Forwards Confirmatory Survey Plan for Fsv Nuclear Station Decommissioning Project,First Final Survey Rept Submittal- Vols 1-5.NRC Comments Incorporated.Spending Plan Attached ML20117P0711996-09-13013 September 1996 Describes Util Plans to Remove Bldg 28 from Plant Facility ML20129A4431996-09-11011 September 1996 Describes Util Plans for Demonstrating That Liquid Effluent Pathway & Surrounding Open Land Areas Satisfy 10 Mrem/Yr Criteria Provided in Plant Final Survey Plan ML20117K5291996-09-0404 September 1996 Provides Notification That Util Will Be Revising Financial Assurance Mechanism That Will Be Used to Cover Remaining Costs of Decommissioning Plant ML20117C7281996-08-22022 August 1996 Discusses Impact of Final Decommissioning Rule & Requests NRC Concurrence That Requirements to Submit & Obtain Approval of License Termination Plan Have Been Satisfied ML20116P3431996-08-16016 August 1996 Describes Actions to Remove Structures & Equipment Items from Fort St Vrain Facility for NRC Info.Requests That NRC Advise Util of Wishes to Perform Confirmatory Survey of Any Parts of New Fuel Storage Building Before 960903 ML20133D7551996-08-14014 August 1996 Provides Environ Survey & Site Assessment Program'S (Essap) Comments Re Review of Fsv Nuclear Station Decommissioning Project Final Survey Rept ML20116M0771996-08-14014 August 1996 Provides Suppl Response to Re Insp Rept 50-267/96-01 in Jan 1996 Re NRC Concerns About Fsv Final Survey Program.Specifically,Bias in Instrumentation Response Overestimating Amount of Contamination Present ML20116M1841996-08-13013 August 1996 Forwards Util Responses to NRC Comments in Re Use of in-situ Gamma Spectroscopy to Measure Exposure Rates During Plant Final Survey.Approval to Use in-situ Gamma Spectroscopic instrument,Microspec-2,requested ML20116K0061996-08-0909 August 1996 Submits Fort St Vrain Nuclear Station Decommissioning Project Final Survey Rept ML20116M1241996-08-0808 August 1996 Responds to NRC Bulletin 96-004, Chemical,Galvanic,Or Other Reactions in Spent Fuel Storage & Transportation. Informs That Modular Vault Dry Storage Sys Is Not Susceptible to Problems Addressed in Bulletin ML20116F3611996-08-0202 August 1996 Submits Revised Documentation for Fort St Vrain Final Survey Program ML20116F8141996-08-0202 August 1996 Informs of Util Intent to Modify Fort St Vrain Control Room,Which Will Make Certain Final Survey Locations Unavailable for Further Review.Final Survey Efforts Are Complete ML20116A4511996-07-19019 July 1996 Requests NRC Approval of Proposed Method to Fsv Final Survey Plan to Determine Exposure Rates in Prestressed Concrete Reactor Vessel 1999-03-26
[Table view] Category:RESEARCH INSTITUTION/LABORATORY TO NRC
MONTHYEARML20235Z2621987-07-0808 July 1987 Requests Addl Info from Util Re Bldg 10 Seismic Design, Including Descriptive Matl for PILAY2 Computer Code & Sketches or Drawings Showing Caisson/Slab/Wall Configurations ML20237E0051986-10-16016 October 1986 Forwards Final Version of Facility Limiting Condition for Operation 4.1.9 Technical Evaluation Rept for Review & Approval.Related Info Encl ML20197A7701986-05-0202 May 1986 Forwards Technical Assistance to Region IV (Fort St Vrain), Monthly Progress Repts for Feb & Mar 1986 ML20098H1721984-08-21021 August 1984 Provides Replies & Comments to Util Re Tech Spec Limiting Condition for Operation 4.1.9 in Advance of 840823 Meeting W/Util in Arlington,Tx ML20138A6241984-06-19019 June 1984 Submits Description of Method Used to Estimate Release of Respirable Radioactive Matl & Brief Comparison of Release from LWR Fuel to That Expected from HTGR Fuel ML20039F6711982-01-0505 January 1982 Forwards Review of PSC of Co Proposed Inservice Insp Program. Milestones on Inservice Insp Have Been Met ML20004F9021981-06-16016 June 1981 Summarizes Implementation & Progress of Review of Fort St Vrain Items & Applicability to Htgrs. ML20004F6101981-05-12012 May 1981 Submits Monthly Repts for Tasks Initiated on 810417 Re NUREG-0737, Applicability of TMI Action Plan Requirements to Fort St Vrain & Htgrs, for Period Ending 810515 ML19257C7431979-04-24024 April 1979 Forwards Rept to NRC on Effect of Installing Core Region Constraint Devices on Seismic Response of Plant Core. ML19260E1891979-04-24024 April 1979 Forwards Final, Rept to NRC on Effect of Installing Core Region Constraint Devices on Seismic Response of Facility Core. Unchanged from Draft Version.Submits Response to Structural Engineering Branch Comments ML19289C3761978-12-21021 December 1978 Responds to NRC 781121 Request for Aid W/Licensing Review Re Postulated Dbda & Loss of Forced Circulation Accidents. Concludes Each of the New Postulated Cases Results in Max Temp No Greater than FSAR-assumed Worst Case ML20062G2281978-12-19019 December 1978 Summary of 781215 Meeting of Tech Review Comm for Review of Temp Fluctuations in Subj Facil.Topics Discussed Incl Comparison of Displacement Probe & Nuc Detector Signals & Info on Core Status ML19289C3741978-12-13013 December 1978 Forwards Rept to NRC on the PSC Document Entitled Core Fluctuation Investigation Status & Safety Evaluation Rept. Concludes It Is Unlikely That Fluctuation Problem Is Causing Serious Structural Damage as Result of Core Motion 1987-07-08
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OBattelle Columbus Laboratories SOS King Avenue Columbus. ONo 41201 lelephone tbl4i 424 6424 Teles 24-5454 June 19, 1984 Mr. Stanley P. Turel U.S. Nuclear Regulatory Comission 5650 Nicholson Lane '
Rockville, Maryland 20852
Dear Mr. Turel:
Under Contract No. NRC-04-84-ll3, we are required to estimate the mass of respirable radioactive material expected to be released during our experi-ments with surrogate HTGR fuel. In those tests, a model cask loaded with surrogate spent HTGR fuel will be struck by a small shaped charge jet. This letter contains the release estimate, a description of the method used to make the estimate, and a brief comparison of the release from LWR fuel to that expected from HTGR fuel.
Before continuing, I must caution the reader that the release estimates presented in this letter are only estimates. The estimated releases from surrogate HTGR fuel are calculated using correlations developed from experi-ments performed on spent LWR fuel. There are major differences between the two types of fuel, and the extent to which these differences affect the re-lease of radioactive material will not be known until the HTGR experiments are done.
Six tests (three experiments done in duplicate) on model casks loaded with surrogate HTGR fuel will be conducted in July. The tests will simulate, as closely as p,ossible, an attack on a shipment of spelt fuel from the Ft.
St. Vrain comercial power plant. The surrogate fuel will be rods identical to those used in the Ft. St. Vrain reactor except that they are ccmposed of microspheres containing ThC2 only. No U"2 1s included. In each test, two rows of fuel rods will be loaded into holes drilled in a graphite block.
Coolant holes will also be drilled in the graphite block. Spacing of both the fuel rods and the coolant holes will be identical to that found in a full-scale Ft. St. Vrain fuel element. (A description of a Ft. St. Vrain fuel element is attached to this letter.)
- Three pairs of experiments will differ only in the thickness of the graphite between the inside cask wall and the first row of fuel rods. Cut away dia-grams of the model cask / graphite / fuel assemblies for the three different types of tests are shown below.
l 8512120068 851112 PDR FOIA PDR MILLAR84-682 l
/f
, Mr. Stanley P. Turel 2 June 19, 1984 graphite / fuel i graphite /fue1 cas w 11s 7 cas w 11s
[ , [ f a h 1
jet _
lO4 Jet : O O IO path ' Q path l
O Ol i
Tests 1 & 2 Tests 3 & 4 graphite / fuel cas lls ru %
Jet .
~
O O O Ojo path 00 O O Ol Tests 5 & 6 e fuel o coolant hole Cut Away Diagram of Model Cask / Graphite / Fuel l
Assemblies for Experiments l
l Three pairs of tests are being done because we need to learn how the shaped charge jet's effect on a fuel rod changes as the jet's energy decreases. If the jet were to follow the most damaging path through a full-sized HTGR fuel element, it would strike 22 rows of rods and penetrate approximately 14 inches of graphite. As the jet moves through solid material, it loses some of its i energy, and therefore, does slightly less damage to each successive row of l fuel rods. In order to properly scale up the results of our experiments, we i
need to know how much respirable radioactive material is released from fuel rods at various locations in the fuel element.
To estimate the respirable release from the experiments, we are assuming that the shaped charge jet produces a hole of uniform size in each graphite / fuel rod assembly. Previous tests with LWR fuel rods indicate that this hole will be approximately one inch in diameter. If the jet strikes the model fuel
6 Mr. Stanley P. Turel 3 June 19, 1984 element at the point where it can do the most damage, it will disrupt one inch of each of two fuel rods (one rod in each of the two rows). In that case, approximately 5.5 cu em of fuel rod, or 12.2 grams, will be disrupted.
Most of the disrupted fuel will remain in the cask. Some non-respirable particles will leave the cask but fall to the ground very quickly. The dis-rupted fuel of interest to us is that which leaves the cask in respirable form (aerodynamic diameter 13.5 pm). Results of the LWR tests indicate about 1 x 10-3 of the disrupted fuel is released as respirable particles.
Therefore, we estimate that 0.0122 g of the fuel will be released from the model cask in a respirable form.
This estimated release is difficult to interpret unless it is scaled up and compared to the release resulting from an attack on a full-scale cask con-taining an LWR fuel assembly. Unfortunately, the scaling law for HTGR fuel elements cannot be developed until the laboratory scale experiments are com-pleted. The only scaling law currently available is the one developed for the LWR fuel. It is inappropriate to apply that law to the HTGR fuel, and such an application is expected to yield results which significantly under-estimate the release. Very preliminary considerations of scaling appro-priate for HTGR fuel suggest that the scaling factor should be the ratio of the areas of the holes produced by the laboratory-scale and full-scale shaped charge jets. That ratio is not currently available but is expected to be on the order of 20.
Recall that in the experiments the release from two rows of pins was estimated to be 0.0122 g of fuel. In a full-sized HTGR fuel element, the jet could strike 22 rows--11 times as many as it will in the experiment. The preliminary HTGR scaling estimate indicates that the reference (full-scale) shaped charge will disrupt 20 times as much material per row as the precision shaped charge used in the experiments. Thus, the estimated release from a full-scale HTGR ele-ment is:
0.0122 x 11 x 20 = 2.7 grams The release reported for a single LWR fuel assembly was 8.97 grams.II)
This completes our discussion of the estimate of the release from the experi-ments using surrogate HTGR fuel. However, we can provide further insight into the probable consequences of an attack on a shipment of HTGR spent fuel by briefly discussing the differences in the compositions of LWR and HTGR fuel.
II) E. W. Schmidt, M. A. Walters, B. D. Trott, J. A. Gieseke, " Final Report on Shipping Cask Sabotage Source Term Investigation", NUREG/CR-2472, (October,1982).
. s.
~
Mr. Stanicy P. Turel 4 June 19, 1984 4
s
\ l j General Atomic (2) has reported the nuclide content for. spent U-235 fuel !
(once-through) and U-233 fuel (recycle) .as calculated by the GARG0YLE ,
code. We have chosen to base our analysis on'the spent once-through fuel '
- since that is the type currently used. However, the consequinces of dis-persal of recycle fuel can be obtained by using the ratio of the specific activities of the dominant nuclides. (The concentration of transuranic elements in recycle fuel is approximately 8 times that found in once-
- through fuel.)
GARG0YLE data show that the specific activity (Ci/cc) of the ' fission pro-ducts in the HTGR fuel is an order of magnitude less than that found in LWR
, fuel, as can be expected from ithe lower specific power in the HTGR. The specific activity of most the transuranics is 40 to 700 times less than that found in LWR fuel snici was expected because of the low U-238 content of the highly-enriched HTGR once-through fuel . However, the specific activity of Pu-238 in the HTGR fuel is 1/4 of that of LWR fuel. The high Pu-238 concen-tration i_s due to the high U-235 content and the favorable production route
- by neutron capture and e decay from U-235 to Np to Pu-238.
The' Pu-238 concentration is very significant to our study. In the evalu-ation of the consequences of the malevolent dispersal of LWR fuel, Pu-238 1
was found to account for 40 percent of the latent cancer fatalities. Since i- its concentration is ^relatively higher than all of the other significant nuclides in~HTGR fuel, Pu-238 can be expected to dominate the consequences in a release' of HTGR fuel. However, its concentration is less than that in LWR fuel so we do not expect the consequences of a release of HTGR fuel to be as great as those of a release of an equal amount of LWR fuel.
Sincerely, -
/&d&d<sm )
i IAudeen Walters Fentiman Program Manager l
Nuclear Systems Section i
AWF:erc Enc.
i l
I2) Hamilton, C. J., et al. , "HTGR Spent Fuel Element Composition 'and Fuel Element Block Flow", GA-A-13886 (Vol 1); 7/76.
~..
DESCRIPTION __0F FT. ST. VRAIN FUEL ELEMENT A Ft. St. Vrain HTGR fuel element is a graphite block 31.2*-in high with a hexagonal cross section 14.2-in* across the flats. Axial holes for coolant and fuel are located in a triangular array on a 0.74-inch pitch.
In each set of three holes in the triangular array, one is a coolant hole
~
4 and two are fuel holes. The 0.625-inch diameter coolant holes completely penetrate the block and, when in the reactor, are aligned with coolant holes in blocks above or below. The 0.50-inch diameter fuel holes ar.e closed at each end and hold 2-inch long graphite rods which contain (Th-U)
C 2 r ThC2 particles coated with pyrolytic carbon. At the axial center on the top of the block is a blind hole no..inally 1-inch diameter to accommodate a lifting device for handling the block. Surrounding the lifting hole are six 0.5-inch diameter coolant holes. A 0.5-inch diameter hole at each corner of the block holds burnable poison. There are 210 fuel holes,102 large coolant holes, 6 small coolant holes, and 6 burnable poison holes.
- Rounded to 3 significant figures.
i
- ~-, -,y ,
w y 4 w p,- n w-r- n---