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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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4 UNITED STATES 1
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2 NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20565 0001
%***,*/ October 14, 1999 Mr. Robert Woolley, Manager AVLIS Nuclear Regulation Policy and Licensing U.S. Enrichment Corporation Two Democracy Center.
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6903 Rockledge Drive Bethesda, MD 20817
SUBJECT:
AVLIS CRITICALITY CODE VAllDATION REPORT (TAC NO. L32076)
Dear Mr. Woolley:
This refers to your le+ter dated April 22,1998, regarding the submitted Atomic Vapor Laser Isotope Separation (AVLIS) process validation report, which was provided in support of the use of SCALE-4.3 to perform nuclear criticality safety evaluations for the AVLIS facility. Following receipt of the initial report, two requests for additional information (RAls), dated June 10,1998, and December 4,1998, were transmitted and your responses (dated October 22,1998, and A.pril 12,1999) were received. The Nuclear Regulatory Commission (NRC) has now completed its review of your initial submittal and your responses to these RAls. Please find enclosed a copy of our Safety Evaluation Report (SER) entitled " Nuclear Criticality Safety Scale Code Validation Report for the Atomic Vapor Laser Isotope Separation (AVLIS) Facility."
Our review of your submittals demonstrates that the validation report of April 22,1998, did not provide reasonable assurance that the code can be used safely with the proposed margins over the stated area of applicability (AOA). The underlying issues described in the attached SER have been similar to those encountered in the validation reports of other fuel facility licensees, i and are thus generic to the industry as a whole. The major deficiencies in the validation report j l
may be summarized c rollows-l
- There was inadequate treatment of trends in the bias or justification of the proposed !
margins of subcriticality (minimum margin of 0.02).
4 e The stated AOA did not match the range of parameters covered by the analyzed benchmark cases. No provision was made for additional uncertainties due to the extension of the AOA over these' gaps in parameter space.
- The validation process was not documented in sufficient detail to permit independent reconstruction of results by the NRC.
- The validation report did not provide enough AVLIS-specific data to permit NRC to conclude that the codo was sufficiently validated for the full range of AVLIS operating conditions.
The purpose of this SER was initially to provide reasonable assurance that the SCALE criticality code could be used with an adequate margin of safety to determine the criticality safety basis for the proposed AVLIS process. However, in light of the cancellation of the AVLIS project in June 1999, this SER now documents the technical basis for NRC findings regarding the hpOS,t 9910200325 991014 PDR ADOCK 070030 9
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' gy' e
R. W. Woolley, USEC 2
- adequacy of the submitted validation report, including identifying outstanding technical issues
-(open items). Although AVLIS has been suspended and a completed application was never received, experience during the review of this validation report has generic applicability to future
- licensing actions, especially for proposed operations where the area of applicability is being l . extended beyond that normally encountered in traditional fuel cycle facilities. Because of the
.open items identified, the NRC has concluded that the AVLIS validation report does not provide an adequate generic or specific validation.
i If you have any questions regarding this matter, please contact Dr. Christopher Tripp of my staff at (301) 415-7733.
Sincerely, .
- Robert C. Pierson, Chief A L ( Special Projects Branch l , Division of Fuel Cycle Safety
> and Safeguards, NMSS Docket:I70-3089
Enclosure:
Safety Evaluation Report r:
L_ J