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Category:CORRESPONDENCE-LETTERS
MONTHYEARML20217F4581999-10-14014 October 1999
Forwards SER Entitled, Nuclear Criticality Safety Scale Copde Validation Rept for Atomic Vapor Laser Isotope Separation (Avlis) Facility, Documenting Technical Basis for NRC Findings Re Adequacy of Submitted Validation Rept
ML20205N2971999-04-14014 April 1999
Forwards Summary of 990317 Meeting Between Us Enrichment Corp Re Environ Avlis Facility.Without Encl
L-99-003, Provides Response to NRC RAI Re Scale 4.3 Code Validation Rept.Attachment to Ltr Provides Written Response to Latest NRC Rai.Info in Attachment Demonstrates Actions Listed. Correspondence Contains No New Commitments1999-04-12012 April 1999
Provides Response to NRC RAI Re Scale 4.3 Code Validation Rept.Attachment to Ltr Provides Written Response to Latest NRC Rai.Info in Attachment Demonstrates Actions Listed. Correspondence Contains No New Commitments
L-98-012, Informs That Reevaluation of Avlis Licensing Schedule Mentioned in ,Has Been Completed.Revised Schedule, Including pre-application Submittals Are Contained in Encl1999-01-0808 January 1999
Informs That Reevaluation of Avlis Licensing Schedule Mentioned in ,Has Been Completed.Revised Schedule, Including pre-application Submittals Are Contained in Encl
ML20197G6741998-12-0404 December 1998
Informs That NRC Cannot Endorse Usecs Use of Scale 4.3 Codes & Cross Sections at Present Time.Nrc Suggests That Technical Meeting Be Scheduled to Discuss Stated Issues in Detail
ML20155C1561998-10-22022 October 1998
Provides Addl Info Defining Licensee Approach to Criticality Safety to Assist in NRC Understanding of Scope of Application for Validated Methods.Endorsement of Scale 4.3 Codes & Cross Sections Applied to Avlis Matls,Requested
L-98-009, Forwards Revised Us Enrichment Corp Avlis Enrichment Plant QA Program Description, Per Request of NRC1998-08-12012 August 1998
Forwards Revised Us Enrichment Corp Avlis Enrichment Plant QA Program Description, Per Request of NRC
L-98-007, Requests to Meet W/Nrc at Earliest Convenience to Discuss Methods Being Used to Conduct Isa.Licensee Believes It Prudent to Delay ISA Methods Submittal Pending Discussions at Meeting1998-07-0101 July 1998
Requests to Meet W/Nrc at Earliest Convenience to Discuss Methods Being Used to Conduct Isa.Licensee Believes It Prudent to Delay ISA Methods Submittal Pending Discussions at Meeting
NUREG-1520, Recommends That 980504 Avlis Licensing Process License Application Be One Document W/O Part I/Part II Distinction. Staff Recommended Example of Application & Environ Rept Format,Encl1998-06-23023 June 1998
Recommends That 980504 Avlis Licensing Process License Application Be One Document W/O Part I/Part II Distinction. Staff Recommended Example of Application & Environ Rept Format,Encl
ML20248M0401998-06-10010 June 1998
Forwards Request for Addl Info Identified in Encl to Ltr Re Avlis Criticality Code Validation Rept.W/O Encl
L-98-004, Forwards Proposed Format & Content for License Application Including Regulatory Guidance Used,For NRC Review1998-05-0404 May 1998
Forwards Proposed Format & Content for License Application Including Regulatory Guidance Used,For NRC Review
L-98-005, Forwards Copy of Avlis Nuclear Criticality Safety Rept Validation of Scale 4.3,WBS 1.6.1.2, for Review.Licensee Requests That Fees for Rept Be Waived IAW 10CFR170.31, Footnote 5 (C)1998-04-22022 April 1998
Forwards Copy of Avlis Nuclear Criticality Safety Rept Validation of Scale 4.3,WBS 1.6.1.2, for Review.Licensee Requests That Fees for Rept Be Waived IAW 10CFR170.31, Footnote 5 (C)
L-98-006, Summarizes Progress on pre-application Activities Since Usec'S & Provides Response to NRC 980327 Request for Avlis Schedule Info1998-04-17017 April 1998
Summarizes Progress on pre-application Activities Since Usec'S & Provides Response to NRC 980327 Request for Avlis Schedule Info
L-98-003, Provides Corrected Page Re Avlis Quality Assurance Program Description,Encl w/980303 Ltr1998-03-30030 March 1998
Provides Corrected Page Re Avlis Quality Assurance Program Description,Encl w/980303 Ltr
ML20217G0941998-03-27027 March 1998
Requests That Licensee Submit Portions of Application Re Avlis,Which Are Not Site Specific.Nrc Has Recently Increased Allocated Staff Resources During Fy for pre-licensing Efforts on Expected Application by Licensee
L-98-002, Provides Corrected Replacement for Avlis QA Program Description Encl w/980223 Ltr.Avlis QA Program Description Encl Herewith Corrects Errors1998-03-0303 March 1998
Provides Corrected Replacement for Avlis QA Program Description Encl w/980223 Ltr.Avlis QA Program Description Encl Herewith Corrects Errors
L-98-001, Provides Responses to RAI ,re Avlis QA Program Description of Ltr as Revised by Ltr . Encl 2 Provides Revised QA Program Description1998-02-23023 February 1998
Provides Responses to RAI ,re Avlis QA Program Description of Ltr as Revised by Ltr . Encl 2 Provides Revised QA Program Description
L-97-003, Provides Response to 970821 RAI Re Avlis QA Program Description.Revised Us Enrichment Corp Avlis QA Program Description, Encl1997-10-0303 October 1997
Provides Response to 970821 RAI Re Avlis QA Program Description.Revised Us Enrichment Corp Avlis QA Program Description, Encl
L-97-002, Discusses Avlis pre-application Activities & Apprises of Latest Info to Assist in Planning1997-08-27027 August 1997
Discusses Avlis pre-application Activities & Apprises of Latest Info to Assist in Planning
ML20137Q7481997-03-26026 March 1997
Forwards,For Docket 70-3089, Usec Avlis QA Program Description
1999-04-14
[Table view]
Category:OUTGOING CORRESPONDENCE
MONTHYEARML20217F4581999-10-14014 October 1999
Forwards SER Entitled, Nuclear Criticality Safety Scale Copde Validation Rept for Atomic Vapor Laser Isotope Separation (Avlis) Facility, Documenting Technical Basis for NRC Findings Re Adequacy of Submitted Validation Rept
ML20205N2971999-04-14014 April 1999
Forwards Summary of 990317 Meeting Between Us Enrichment Corp Re Environ Avlis Facility.Without Encl
ML20197G6741998-12-0404 December 1998
Informs That NRC Cannot Endorse Usecs Use of Scale 4.3 Codes & Cross Sections at Present Time.Nrc Suggests That Technical Meeting Be Scheduled to Discuss Stated Issues in Detail
NUREG-1520, Recommends That 980504 Avlis Licensing Process License Application Be One Document W/O Part I/Part II Distinction. Staff Recommended Example of Application & Environ Rept Format,Encl1998-06-23023 June 1998
Recommends That 980504 Avlis Licensing Process License Application Be One Document W/O Part I/Part II Distinction. Staff Recommended Example of Application & Environ Rept Format,Encl
ML20248M0401998-06-10010 June 1998
Forwards Request for Addl Info Identified in Encl to Ltr Re Avlis Criticality Code Validation Rept.W/O Encl
ML20217G0941998-03-27027 March 1998
Requests That Licensee Submit Portions of Application Re Avlis,Which Are Not Site Specific.Nrc Has Recently Increased Allocated Staff Resources During Fy for pre-licensing Efforts on Expected Application by Licensee
1999-04-14
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/d g/"% '4 UNITED STATES g j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30666 0001 t
. m , *# December 4, 1998 Mr. Robert Woolley Manager, AVLIS Nuclear Regulatory Policy !
and Licensing ;
U.S. Enrichment Corporation '
Two Democracy Center 6903 Rockledge Drive Bethesda, MD 20817
SUBJECT:
AVLIS CRITICALITY CODE VAllDATION REPORT (TAC NO. L32076)
Dear Mr. Woolley:
i in a letter dated October 22,1998, "AVLIS Criticality Code Validation," L-98-011, the United States Enrichment Corporation (USEC) provided further discussion of the applicability of the Atomic Vapor Laser Isotope Separation (AVLIS) Criticality Code Validation Report submitted to the U. S. Nuclear Regulatory Commission (NRC) on April 22,1998, and the general rules of :
practice for AVLIS criticality safety analyses that will be incorporated into the nuclear criticality l safety chapter of the AVLIS license application. USEC concluded that the selected ;
benchmarks adequately cover AVLIS materials, configurations of interest, and ranges of
- applicability, including the intermediate fission energy spectrum. Based upon these ;
conclusions, USEC requested endorsement of the SCALE 4.3 codes and cross sections as :
applied to AVLIS materials and systems.
{
t On November 4,1998, NRC technical staff toured the AVLIS Demonstration Pilot located at the Lawrence Livermore National Laboratory. This tour served to greatly facilitate the understanding of AVLIS-specific issues; however, NRC cannot endorse USEC's use of the SCALE 4.3 codes and cross sections at this time, Although NRC finds merit with USEC's philosophy and approach to criticality safety, NRC has concluded that further information from USEC is necessary to determine the acceptability of the report for the proposed area of applicability. NRC recognizes that it is not necessary or currently possible for a benchmark set i to cover every parameter over the full range of possibilities. However, it is NRC's expectation j that USEC evaluate sufficient experimental evidence to support statistically significant trends for ,
the areas of requested operation or limit the validation range to those areas where sufficient data exists. NRC has identified the following general areas that require further USEC review ,
and discussion: !
-(1) Analysis and review of process conditions occurring in the intermediate energy range and the adequacy of current experimental evidence to support these cases; (2) Application of appropriate bias and margins of safety for the extension of enrichment i values in the range of 5 - 10 weight percent; (3) Review of multiple parameter interdependence and perturbation for those parameters specific to the AVLIS process; and ,
6O (4) Adequacy of available cross-sections for high temperature metals and systems that are part of the AVLIS process or supporting rationale that such conditions are not possible.
~ m ptryC O W Dn W yf 9812100062 981204 L gg h m,4gah;n #d }I PDR ADOCK 07003089 C PDR L
R. L. Woolley, USEC 2 g4 g i
a in regard to item 4 above, the October 22nd letter concluded that high temperature systems were not of concern to the AVLIS validation since moderation was required for criticality and the introduction of such material would reduce operating temperatures to values where the SCALE 4.3 cross sectich sets are adequately validated. NRC finds that such a conclusion is not reasonable for all possible scenarios since final system temperatures would depend upon mass rate inflow and reaction rate dynamics. Thus, NRC believes that further review of high temperature cross section set validation is warranted.
NRC suggests that a technical meeting be scheduled to discuss these issues in detail. Should you have any questions or wish to schedule such a meeting, please contact Jack Davis of my staff i at (301) 415-7256.
Sincerely, 05.alsignedey Robert C. Pierson, Chief Special Projects Branch l
Division of Fuel Cycle Safety and Safeguards, NMSS Docket No. 70-3089 cc: Mr. Ronald P. Koopman, LLNL
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DISTRIBUTION Docket 70-3089 JPCJlc..ComeerdFCSS 3 r/f PUBLIC APersinko, FSPB FSPB r/f PTing, FCOB NMSS r/f CEmeigh, FCLB c:\ Davis'amaster\avlis\ val.rpt OFC SPB C SPB 6 SPB C SPB n NAME hN) JDavis JMuszkie b 3hh RPi< Eson DATE 12/ l B8 12/3 Bd 12/ hS8 12/ 4 B8 Cm Cover E= Cover & Enclosure I N= No Copy OFFICIAL RECORD COPY