ML19343A006

Ctr 2018/01, Issue D, SAFKEG-HS 3977A, Sarp Update Matrix for Thorium Target

ML19343A006
Person / Time
Site:	07109338
Issue date:	12/03/2019
From:	Croft Associates Limited
To:	Office of Nuclear Material Safety and Safeguards
Shared Package
ML19343A003	List: ML19343A004 ML19343A005 ML19343A006 ML19343A007 ML19343A008 ML19343A009 ML19343A010 ML19343A011 ML19343A012 ML19343A013 ML19343A014 ML19343A015 ML19343A016
References
TAC L24678 CTR 2018/01, Issue D
Download: ML19343A006 (53)

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SAFKEG-HS 3977A CTR 2018/01 Docket Number 71-9338 Issue D Page 1 of 53 SAFKEG-HS 3977A SARP Update Matrix for Thorium Target Title SAFKEG-LS 3977A SARP Update Matrix for Thorium Target Number CTR 2018/01 Issue D

File Ref CTR2018-01-D-v3-Update matrix for Thorium target.docx Compiled Checked A L Ferguson R A Vaughan Approved Issue Date 3rd December 2019 R A Vaughan Croft Associates Ltd, F4 Culham Science Centre, Abingdon, Oxfordshire, OX14 3DB. 01865 407740

SAFKEG-HS 3977A CTR 2018/01 Docket Number 71-9338 Issue D Page 2 of 53 Contents 1 Notes on methodology and content............................................................................................................................. 3 2 Reason for the changes in the SARP in updating from Rev 13 to Rev 14.................................................................. 3 3 Reason for the changes in the SARP in updating from Rev 14 to Rev 15.................................................................. 3 4 Reason for the changes in the SARP in updating from Rev 15 to Rev 16.................................................................. 4 5 SARP Changes............................................................................................................................................................ 5 NRC Questions and Croft Responses........................................................................................................................... 29 Appendix A New or edited Supporting Documents provided in the SARP from Rev 13...................................... 49 Appendix B Contents Type CT Thorium Target............................................................................................. 52

SAFKEG-HS 3977A CTR 2018/01 Docket Number 71-9338 Issue D Page 3 of 53 1 Notes on methodology and content This Update Matrix document (CTR 2018/01) details the changes in the SAFKEG-HS 3977A SARP (CTR 2008-11) in updating from Rev 13 to Rev 14, Rev 14 to Rev 15, Rev 15 to Rev 16, and Rev 16 to Rev 17.

This SARP update is to allow Thorium targets to be carried in the package as new Contents Type 6 (CT-6).

This Update Matrix document will be updated during the NRC review process to include responses to questions from the NRC, thereby fully documenting all changes made during the entire SARP update.

Minor editorial changes in the SARP to clarify and correct errors are also detailed in this Update Matrix document.

This Update Matrix document (CTR 2018/01) provides the following in updating from Rev 13 for the addition of Thorium targets.

Details of SARP and supporting document changes proposed with reason for the change - Table 1 (1A, 1B, 1C)

Question and Response Matrix - Table 2 (2A, 2B, 2C - these include all the updates made to the SARP to answer all the questions posed by the NRC)

List of new or edited supporting documents provided in the SARP - Table 3, Appendix A Explanation of the approach taken for new contents type CT-6 (radioactive thorium target) - Appendix B.

2 Reason for the changes in the SARP in updating from Rev 13 to Rev 14 Ac-225 is being developed for medical purposes and LANL have developed a methodology of producing Ac-225 by irradiating of a thorium target in a proton beam. The SAFKEG-HS 3977A has been identified by LANL as appropriate package for shipping irradiated thorium targets and Croft have been contracted to have irradiated thorium targets added to the SARP.

3 Reason for the changes in the SARP in updating from Rev 14 to Rev 15 The SARP has been updated in response to the NRC RAIs provided on 30 Oct 2018. The major change is a complete revision of the shielding calculations for CT-6 Thorium target using an energy bin approach to determine which radionuclides contribute significantly to the package external radiation levels and to determine the actual maximum radiation levels. Additionally, the SARP has been updated to cover only the BNL thorium target and remove reference to the LANL thorium target which is no longer proposed to be shipped the SAFKEG-HS 3977A package.

The explanation of the contents limit for CT-6 Thorium target based on a revised calculation of the activities of 498 radionuclides produced by the irradiation target and shielding calculations for 498 radionuclides is given in Appendix B of this report (CTR 2018/01) which has been completely revised for the new energy bin approach.

On fabrication of a dummy CV and plug with the piston seal (as specified for CT-6 Thorium target in the SARP at Rev 14), it was found to be very difficult to fit the plug into the CV. Consequently, the CV plug having a piston seal is no longer specified in the SARP and instead the contents are to be carried in an insert (Design No.

4109, see Fig 1-5C, in Section 1 of the SARP). The SARP has been revised to take out all reference to the CV plug having a piston seal that was added to the SARP at Rev 14 and the new insert Design No. 4109 added where appropriate. The changes are identified in Table 2B of this document.

SAFKEG-HS 3977A CTR 2018/01 Docket Number 71-9338 Issue D Page 4 of 53 4 Reason for the changes in the SARP in updating from Rev 15 to Rev 16 Correction of referencing errors. The body text in Sections 4, 5, 7 and 8 incorrectly referred to a sealed plug or sealed plug seal, this feature was replaced with insert Design No # 4109.

5 Reason for the changes in the SARP in updating from Rev 16 to Rev 17 To clarify the definition for Contents Type 6 in the Croft package 3977A, by specifying the contents in terms of energy bins and the associated limits for each energy bin.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 5 of 53 6 SARP Changes These tables contain notes on all the SARP Page Changes and supporting Document Changes.

Table 1A Summary of SARP Changes and Supporting Document Changes for Rev 14 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Sections 0 to 8 Throughout the SARP The Rev status has been updated to Rev 14 for all SARP pages and not just pages with changes.

This change has been made to simplify management of the SARP for which master documents are electronic Word documents. This change reduces the potential for editorial errors and also facilitates the production of pdf copies produced for reviewers (simplified as each Section will be complete and not just be separate pages All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

Throughout the SARP These are shown in the Compare documents provided for each Section.

Editorial changes have been made to correct errors, standardise terminology, etc.

To correct errors, standardise terminology, etc.

All pages Header throughout the SARP Footer throughout the SARP Page Rev status amended to Rev 14 for all pages.

Changes required solely to change from page control to document control to facilitate future update.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 6 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Filename updated and date removed Date not needed as it is the same for all pages as shown in Section

0.

Section 0 - Contents Page 0-2 Table Updated for Rev 14 Editorial Section 0.2 Page status changed throughout Update to of Rev Documents in Section 1.3.3 Headings have been added for the drawings for each version of the CV.

The drawings for the Sealed Split Lid Version of the CV have been added.

This change is required to accommodate a thorium target.

Documents in Section 3.5.2, Appendix The document references, status and titles have been edited (for those docs having an External Report Number (ETR #) added).

The ETR #s and eFilenames have been added to facilitate finding electronic copies of these documents (they did not have Ref

1. s).

Documents in Section 4.5.2, Appendix Details for CS2018/01 added Section 1 - General Information Pages - various Throughout Section Editorial changes made as necessary for addition of the sealed split CV lid.

Editorial and clarification Page 1-3 Section 1.2.1.3 Edited to add the CV seal plug having an O-ring seal.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 7 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 1-3 Section 1.2.1.3, 5th para Details of the sealed split CV lid added For new Contents Type CT-6 Page 1-4 Section 1.2.1.4 New Figures referenced Page 1-4 Section 1.2.1.5 New Figures referenced Page 1-8 Figure 1-1c added Depicting split CV lid Page 1-8 Details of the package with sealed split CV lid added For new Contents Type CT-6 Page 1-12 Figure 1-2c added Shows new sealed split CV lid Page 1-16 Figure 1-3c added Shows new sealed split CV lid Page 1-19 Figure 1-4c added Shows new sealed split CV lid Page 1-21 Table 1.1 Contents mass limit for sealed split CV lid added For new Contents Type CT-6 Page 1-24 Table 1.2 CTs renumbered CT-3 Gas reinstated [as Rev 11 of the SARP]

CT-6 added Editorial adjustment Deleted from the SARP at Rev 13 in error.

For new Contents Type CT Thorium target Page 1-27 Table 1.3.3 CT-3 Gas reinstated [as Rev 11 of the SARP]

Deleted from the SARP at Rev 13 in error.

Page 1-30 Table 1.3.6 CT-6 added For new Contents Type CT Thorium target Page 1-35 Table 1.4.3 CT-3 Gas reinstated [as Rev 11 of the SARP]

Deleted from the SARP at Rev 13 in error.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 8 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 1-38 Table 1.4.6 CT-6 added For new Contents Type CT Thorium target See also Appendix B Page 1-46 Section 1.3.3.3 added Drawings for the package having the new sealed split CV lid added For new Contents Type CT Thorium target Section 2 - Structural Evaluation Pages 54, 2-55, 2-58, Table numbering corrected.

Editorial Section 3 - Thermal Evaluation Page 3-4a Section 3.1.3, 4th para Comment on temperatures for CT-6 added.

For new Contents Type CT Thorium target Page 3-23 Section 3.5.2 Document references ETR added for MURR reports and Mallinckrodt report.

The ETR #s have been added to facilitate finding electronic copies of these documents (they did not have Ref #s).

Section 4 - Containment Evaluation Page 4-1 and elsewhere Section 4.1, 1st para and elsewhere Edited to accommodate new sealed split CV lid For the new package assembly for CT-6.

Page 4-3 Figure 4-3 Figure 4-3 added.

For the new sealed split CV lid for CT-6.

Page 4-4 Table 4-1, note (2) and last para.

Note re dose rate for CT-4 added.

For the new package assembly for CT-6.

Page 4-5 Section 4.2.2, 2nd and 3rd paras.

Edited for reinstatement of CT-3 (gas) and CT-6 (thorium).

Editorial for reinstatement of CT-3 and new CT-6.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 9 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 4-6 Section 4.2.4, 4th to 7th paras.

Edited for reinstatement of CT-3 (gas) and CT-6 (thorium).

Editorial for reinstatement of CT-3 and new CT-6.

Page 4-7 Section 4.3.2, 2nd to 4th paras.

Edited for reinstatement of CT-3 (gas) and CT-6 (thorium).

Editorial for reinstatement of CT-3 and new CT-6.

Page 4-8, 4-9 Section 4.3.4.2, 3rd and 4th paras.

Edited for reinstatement of CT-3 (gas).

Editorial for reinstatement of CT-

3.

Page 4-9 Section 4.4.1, 3rd para.

Requirements for testing the plug/body seal of the split lid sealed plug added.

For the new sealed split CV lid for CT-6.

Page 4-9 Section 4.4.2, 3rd para.

Requirements for testing the plug/body seal of the split lid sealed plug added.

For the new sealed split CV lid for CT-6.

Page 4-9 Section 4.4.3, 3rd para.

Requirements for testing the plug/body seal of the split lid sealed plug added.

For the new sealed split CV lid for CT-6.

Page 4-10 Section 4.4.4, 3rd to 5th paras.

Edited for renumbering the CTs and comments on not require a leak test for new CT-6.

For the new sealed split CV lid for CT-6.

Page 4-11 Section 4.5.2 Reference for new calculation sheet CS 2018/01 added.

For the gas contents of new CT-6.

CS 2018/01 Append to Section 4 New calculation sheet CS 2018/01 added.

For the gas contents of new CT-6.

Section 5 - Shielding Evaluation Page 5-1 and elsewhere Section 5.1.1, 1st and 3rd paras.

Editorial re references, figure and table numbering.

Add references and figures for the new sealed split CV lid for CT-6.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 10 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 5-3 Figure 5-2 Figure 5-2 edited to not show the Insert.

The figure shows the shielding but not the insert which does not provide significant shielding.

Page 5-43 Figure 5-3 Figure 5-5 added Shows new sealed split CV lid Page 5-10 Section 5.3.1, three paras following Table 5-3.

Information re MNCP calculations for CT-6 added.

For new CT-6 Page 5-10 Section 5.3.2 Data for neutron sources removed.

None of the radionuclides specified in the contests emit neutrons.

Page 5-11 Section 5.4.1 Editorial changes Clarification Page 5-11 Section 5.4.1, 5th para Information re MNCP calculations for CT-6 added.

For new CT-6 Page 5-12 Table 5-4 Last row of table Editorial [spelling]

Information re MNCP calculations added.

Correction For new CT-6 Page 5-19 Figure 5-14 Figure 5-14 added to show Thorium target locations for MCNP Model For new CT-6 Page 5-22 Section 5.4.2, after Table 5-6 Ref to materials properties for CT-6 added.

For new CT-6 Page 5-23 Section 5.5.1 Ref to calculation method for CT-6 added.

For new CT-6

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 11 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 5-23 Section 5.5.2 Ref to calculations for CT-6 added.

For new CT-6 Page 5-23 Section 5.5.3 Ref to dose rate conversion for CT-6 added.

For new CT-6 Page 5-28 Section 5.5.4.3 Details of 5.5.4.3 MCNP calculations for thorium target added.

For new CT-6 Page 5-32 Section 5.5.6 Ref for new calculation report for CT-6 /01 added.

For new CT-6 Atkins 5163778-HS-REP-001-001 Append to Section 5 New calculation report for CT-6 added.

For new CT-6 Section 6 - Criticality Evaluation Page 6-1, 6-2 Section 6 All details removed.

Consistency and clarification.

The contents of this package are non-fissile and therefore no evaluation for the safety of fissile contents is required.

Section 7 - Operating Procedure Page 7-1 Section 7, 5th para Editorial Clarification Page 7-2 Section 7.1.1 - title & para 8)

Editorial Clarification Page 7-3 Section 7.1.1 - para 11)

Drawing info added For new sealed split lid CV Page 7-4 Section 7.1.2 - para 7)

Editorial Clarification Page 7-5 Section 7.1.3 - Note Editorial Clarification

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 12 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 7-6 Section 7.1.4 - all paras Loading requirements added for sealed split lid CV For new CT-6 Page 7-7 Section 7.1.5 - title & para 4)

Editorial Clarification Page 7-7 Section 7.1.5, 1)

Editorial To be consistent with ANSI N14.5 Section 7.6.4 acceptance criterion Page 7-8 Section 7.2 1st para Section references added Clarification & for new CT-6 Page 7-9 Section 7.2.2 - paras 1) & 6)

Editorial for contamination added Clarification Page 7-10 Section 7.2.3 - paras 1) & 6)

Editorial for contamination added Clarification Page 7-11 Section 7.2.4 - all paras Unloading requirements added for sealed split lid CV For new CT-6 Page 7-14 Section 7.3,2 para 12)

Requirement added to ovoid damage Consistency Page 7-14 Section 7.1.4 - all paras Loading requirements added for sealed split lid CV For new CT-6 Page 7-14 & 71-15 Section 7.3.3 - all paras Requirements added for shipment of empty package having a sealed split lid CV For new CT-6 Section 8 - Acceptance Tests & Maintenance Program Page 8-1 Section 8, 4th para Para added Consistency with Section 7 Page 8-2 Section 8.1.2 Drawing info added For new sealed split lid CV and clarification Page 8-2 Section 8.1.3 - 2nd para as specified added Clarity

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 13 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 8-2 Section 8.1.4 - 1st para Editorial For new CT-6 Page 8-3 Section 8.1.4 penultimate para Leak testing requirements added for new sealed split lid CV For new CT-6 Page 8-3 Section 8.1.5.2 - 3rd para Editorial For new CT-6 Page 8-4 Section 8.1.5.5 and 8.1.5.6 Drawing info added For new sealed split lid CV and clarification Page 8-6 Section 8.2 - 4th para as specified added Clarity Page 8-7 Section 8.2.2.3 - all paras Loading requirements added for sealed split lid CV For new CT-6 Page 8-8 Section 8.2.3.1 - 2nd paras Drawing info added For new sealed split lid CV and clarification Page 8-8 Section 8.2.3.2 - para 3) as specified added Clarity Page 8-9 Section 8.2.3.2 - para 8) as specified added Clarity Page 8-9 Section 8.2.3.3 - title Editorial Clarification Page 8-9 Section 8.2.3.3 - para 6)

Drawing info added For new sealed split lid CV and clarification Page 8-10 Section 8.2.3.3 - para 7)

Reference added to the section giving the leak test requirements rather than repeating them Consistency Page 8-10 Section 8.2.3.3 - para 8) as specified added Clarity Page 8-10 Section 8.2.3.4 - para 2) as specified added Clarity Page 8-11 Section 8.2.3.5 - para 6) as specified added Clarity Page 8-11 Section 8.2.3.6 - para 2) as specified added Clarity

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 14 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 14 SARP Page or Doc Location Change Reason for Change Page 8-11 Section 8.2.3.7 - title para 2)

Editorial as specified added Clarity Page 8-12 Section 8.2.5.3 as specified added Clarity Page 8-13 Table 8-1 Insert O-ring added Split lid sealed plug O-ring Completeness For new sealed split lid CV

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 15 of 53 Table 1B Summary of SARP Changes and Supporting Document Changes for Rev 15 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Sections 0 to 8 Throughout the SARP The Rev status has been updated to Rev 15 for all SARP pages and not just pages with changes.

SARP update Throughout the SARP Editorial changes have been made to correct errors, standardise terminology, etc.

To correct errors, standardise terminology, etc.

Section 0 - Contents Page 0-3 Section 0.1 Table updated Page 0-6 Section 0.2 Plug design changed to remove the piston seal: 1C-7947 Trials showed that the piston seal made it difficult to fit the plug to the CV body.

A new insert Design No. 4109 is to be used to provide confinement.

Page 0-7 Section 0.2 PCS 038 now issue J New shielding limits Page 0-8 Section 0.2 CS 2019-02 added New pressure due to radiolysis calculation Page 0-9 Section 0.2: Documents in Section 5.5.2, Appendix New Atkins report 5183326 replaces existing report 5163778.

Updated shielding calculations.

Section 1 - General Information Page 1-3 Section 1.2.1.3, 1st para 8th para Fig ref for sealed split lid deleted.

Details for sealed split lid deleted.

Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 16 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 1-4 Section 1.2.1.4 Fig ref for sealed split lid deleted.

Update Page 1-4 Section 1.2.1.6, 1st para Fig ref for sealed split lid deleted.

Update Page 1-8 Section 1.2.1.8 Fig 1-1c for sealed split lid deleted, subsequent Figures re-numbered.

Update Page 1-12 Section 1.2.1.8 Fig 1-2c for sealed split lid deleted, subsequent Figures re-Update Page 1-16 Section 1.2.1.8 Fig 1-3c for sealed split lid deleted Update Page 1-19 Section 1.2.1.8 Fig 1-4c replaced (was for sealed split lid)

Update Page 1-20 Section 1.2.2.1, 4th para Text edited Clarification re pyrophoricity.

Page 1-20 Section 1.2.2.1, 9th para Text edited for removal of sealed split lid Update Page 1-21 Section 1.2.2.2, 2nd para Table 1-1 Fig ref for sealed split lid deleted.

Details for inset 4109 added Update Page 1-23 Section 1.2.2.2, Fig 1-5e insert 4109 added Update Page 1-24 Section 1.2.2.2, Fig 1-7 revised Update Page 1-25 Section 1.2.2.3, Table 1-2 Details of insert for CT-6 added Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 17 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change PCS 038 Section 2.3 Table 3 References under CT-4 and CT-5 exchanged To correct typographical error.

Page 1-31 Table 1-3-6 Revised contents specification especially with respect to use of insert 4109 and packing for the thorium target.

Jar for the target pieces specified as plastic or metal.

Amended to remove Inconel housing no longer to be shipped.

Other changes are clarification.

To give flexibility to the user.

Page 1-38 Tables 1-4-6 The listed nuclides have been changed to those that contribute significantly to the package surface dose rate.

This is explained in Appendix B to this document (CTR 2018, Issue B).

Page 1-46 Section 1.3.3.3 Drawing details revised for use of insert 4109.

Update PCS 038 ref in SARP Section 1.3.4 PCS 038 Section 1.1 Table 1, Insert added for CT-6 Update PCS 038 Section 2.2 Table 2, Insert added for CT-6 and weights amended Update PCS 038 Section 2.3 Table 3 has been edited:

CT-4 -s for I-131 CT-5 is for Mo-99 Correction PCS 038 Section 2.3 Table 4-has been revised to just include the 17 radionuclides that that contribute significantly to the The radionuclide list has been determined by the shi8elding calculations in new Atkins report

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 18 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change package surface dose rate + Ac-225.

5183326-HS-REP-001 (ref in SARP Section 5.6.2).

Section 2 - Structural Evaluation Page 2-3 Section 2.1.1, 1st para Details revised for use of insert 4109.

Update Page 2-4 Section 2.1.1, last para Details revised for use of insert 4109.

Update Page 2-18 Table 2-10 4109 insert referenced (55x113-SS)

Update Page 2-20 Section 2.2.3, new 3rd para to 7th para added Data added re radiation levels for O-ring seals for CT-6.

RAI Q2.2 New calcs in report Atkins 5183326-HS-REP-001 (in Section 5.6.2).

Section 3 - Thermal Evaluation Page 3-15 Section 3.3.2, new7th para New para added with ref to CS 2019/02 to address pressure rise from radiolysis.

RAI Q2.2 Pressure rise due to radiolysis added.

Page 3-23:

CS 2019-02-A-v2-Safkeg-HS -

Gas generated by radiolysis of moisture in the air Section 3.5.2, Appendix New document info added.

RAI Q2.2 Section 4 - Containment Evaluation Page 4-3 Section 4.1 Fig 4-3 Fig for sealed split lid deleted Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 19 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 4-3 Section 4.1, final paras Data added re radiation levels for O-ring seals for CT-6.

New calcs in report Atkins 5183326-HS-REP-001 (in Section 5.6.2).

Section 5 - Shielding Evaluation Page 5-1 Section 5.1.1, 3rd para Ref to insert 4109 added Update Page 5-4 Section 5.1.1, Fig 5-4 revised to not show seal in the lid plug Update Page 5-7 Section 5.2.1 Fig 5-8 insert 4109 added, subsequent pages re-numbered Update Page 5-8 (was 5-7)

Section 5.2.1, 5th para Requirement to us a pallet added.

Necessary to aid compliance with SARP requirements.

Page 5-9 Section 5.2.1,para above Table 5-1 Last sentence added re CT-6 Thorium Target Clarification Page 5-9 Section 5.2.1, Table 5-1 New data added for CT-6 Thorium Target New data in document 5183326 Page 5-10 Section 5.3.1, 3rd para Reference at end changed to 5.6.2.

Correction Page 5-11 Section 5.3.1, para after Table 5-3 Edited for information in new document 5183326.

To reference new calculations in document 5183326 and provide information from that report.

Page 5-12 Section 5.3.1, final para Reference to Inconel housing removed.

Inconel housing not to be included in the contents.

Page 5-12 Section 5.4.1, 4th para Edited for information in new document 5183326 and reference to Inconel housing removed.

To reference new calculations in document 5183326

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 20 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 5-13 Table 5-4 Additional row added for thorium target.

Footnote 4 updated to reference 5183326 shielding report.

Update Page 5-20 Fig 5-14 Replaced with new shielding model target positions To reference the revised thorium MCNP model in document 5183326 Page 5-23 Section 5.4.2, Table 5-7 Reference changed to new document 5183326 and reference to Inconel housing removed.

New document provided.

Page 5-24 Section 5.5.2, 2nd para Reference changed to new document 5183326.

Report number corrected to CTR 2013/09 and Reference at end corrected to 5.6.2.

New document provided.

Page 5-29 Section 5.5.4.3, 1st para 2nd para and Table 5-15 Beam current edited.

Reference changed to new document 5183326.

Table title amended.

As specified in BNL report C-A/BLIP/001 (ref SARP Section 5.6.2).

For new document provided.

Page 5-29 Section 5.5.4.3 Reference to Inconel housing removed.

Beam current edited.

Inconel housing not to be included in the contents.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 21 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change After Table 5-15 References added.

Information regarding dominant radionuclides (in terms of contribution to dose rates) added with Figure 5-16.

Para added re dose rate calculations and use of insert 4109.

Second para (now third) amended to reference Atkins and BNL reports.

Last para and Figure 5-16 added.

As specified in BNL report C-A/BLIP/001 (ref SARP Section 5.6.2).

To show rapid reduction of activity and dose rates due to radioactive decay.

Update.

Update.

Clarification and explanation of dose rate nuclide contributions.

Page 5-31 Section 5.5.4.4, 2nd para Reference changed to 5.6.2.

Correction Page 5-33 Section 5.6.2 Reference changed to Atkins report 5183326.

New report replaces existing report.

Section 6 - Criticality Evaluation No Changes Section 7 - Operating Procedure Page 7-3 Sections 7.1.1,11)

Insert 4109 added and sealed split lid ref deleted.

Update Page 7-4 Sections 7.1.2, 4)

Note added to require that for insert Design No. 3987 and insert Clarification added - this requirement is in the certificate in para 7. (a).

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 22 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Design No. 4081, new seals shall be fitted prior to each use.

Page 7-4 Sections 7.1.2, 7)

Clarification that only the outer seal should be leak tested in insert Design No. 3987.

Para 8 split to have loading in new para 9).

Clarification Clarification Page 7-5 Sections 7.1.3 Title clarified Clarification Page 7-6 Sections 7.1.4 Revised for use of insert 4109.

Packing requirements for the thorium target amended.

RAI Q7.2 Clarification and consistency.

Page 7-10 Sections 7.2.3, Title & paras 7).

Title clarified Use of jacking screws clarified in para 5).

Correction.

Page 7-11 Sections 7.2.4 Handling requirements for the spaces and jar for the thorium target amended.

RAI Q7.2 Clarification Page 7-13 Sections 7.3.2, 3)

Edited to cover insert 4109 which does not use a tungsten liner.

Update Page 7-14 Sections 7.3.3 Deleted as seal split lid no longer specified in the SARP.

Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 23 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 15 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 7-14 Section 7.4 Requirements for pallets added.

Necessary to aid compliance with SARP requirements.

Section 8 - Acceptance Tests & Maintenance Program Page 8-2 Section 8.1.2 Edited for use of new insert 4109.

Update Page 8-7 Sections 8.2.2.2 - new 1st para Requirement added for new seals to be fitted to the inserts at maintenance.

Clarification added - this requirement is in the certificate in para 7. (a).

Page 8-7 Sections 8.2.2.2 - 2nd para Clarification that only the outer seal should be leak tested in insert Design No. 3987.

Clarification Page 8-7 Sections 8.2.2.3 Deleted as seal split lid no longer specified in the SARP.

Update Page 8-9 Sections 8.2.3.3, 6)

Edited for use of new insert 4109.

Update Page 8-13 Table 8-1 Ref to split lid sealed plug O-rig deleted.

Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 24 of 53 Table 1C Summary of SARP Changes and Supporting Document Changes for Rev 16 Summary of SARP Page Changes and Supporting Document Changes for Rev 16 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Section 0 - Contents Page 0-3 Section 0.1 Section 0 page revision status SARP Update Page 0-4 Section 0.2 Section 1 page revision status SARP Update Page 0-6 Page 0-7 Section 0.2 Table item: Safkeg-HS Design Non 3977A - Split Lid with Insert 4109 Updated component drawings -

see Table 1c at end of this doc.

Drawings corrected to remove sealed plug specification features.

Revision issue corrected.

Page 0-7 Section 0.2 Section 2 page revision status Section 3 page revision status SARP Update Page 0-8 Section 0.2 Section 4 page revision status Page 0-9 Section 0.2 Section 5 page revision status Section 6 page revision status Section 7 page revision status Section 8 page revision status SARP Update Page 0-10 Section 0.2 New page SARP Update.

Section 1 - General Information Page 1-21 Section 1.2.2.2, 2nd para Last sentence deleted.

Insert required.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 25 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 16 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 1-46 Section 1.3.3.3 The revision status of the drawings is given in Section 0.2 Table item: Safkeg-HS Design Non 3977A - Split Lid with Insert 4109.

Drawings have been edited to remove minor features added specifically for the seal in a sealed split lid which is no longer required.

Sealed plug no longer used.

Section 2 - Structural Evaluation Page revision status only - no changes to text SARP Update Section 3 - Thermal Evaluation Page revision status only - no changes to text SARP Update Section 4 - Containment Evaluation Page revision status only - no changes to text SARP Update Section 4 - Containment Throughout the Section The Rev status has been updated to Rev 16 for all SARP pages and not just pages with changes.

Correct text to remove reference to a sealed plug Page 4-4 Section 4.4.1, last para on page

4.

Remove references to Sealed Plug and its associated O-ring seal Correct CT-6 text regarding internal configuration, sealed plug and seal no longer employed:

replaced by insert #4109.

Page 4-5 Section 4.2.2, 2nd and 3rd paras Page 4-6 Section 4.2.2, 4th para Section 4.2.4, 6th para Page 4-7 Section 4.3.2, 2nd and 4th paras Page 4-9 Section 4.4.1, last para.

Section 4.4.2, last para.

Page 4-10 Section 4.4.3, last para

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 26 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 16 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Section 4.4.4, last para Section 5 - Shielding Evaluation Page 5-11 Section 5.3.1, para after Table 5-3 Remove text referring to a sealed split lid.

Sealed plug no longer used.

Page 5-13 Table 5-4, last row, third column Page 5-30 Section 5.5.4.3, 1st para on page 5-30 Section 6 - Criticality Evaluation Page revision status only - no changes to text SARP Update Section 7 - Package Operations Page 7-6 Section 7.1.4, list item 2)

Remove text referring to a sealed split lid.

Sealed plug no longer used.

Section 8 - Acceptance Tests and Maintenance Program Page 8-3 Section 8.1.4, 3rd para deleted Remove text referring to a sealed split lid.

Related to tests on a sealed plug

- no longer used.

Page 8-4 Section 8.1.5.5, Section 8.1.5.6 Text edited to add the insert #

relevant to the drawings for the DU components and reference to a sealed split lid removed.

Clarification.

Sealed plug no longer used.

Page 8-7 Section 8 Last para Text edited to add the insert #

relevant to the drawings for the DU components and reference to a sealed split lid removed.

Clarification.

Sealed plug no longer used.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 27 of 53 Table 1D Summary of SARP Changes and Supporting Document Changes for Rev 17 Summary of SARP Page Changes and Supporting Document Changes for Rev 17 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Section 0 - Contents Page 0-3 Section 0.1 Section 0 page revision status SARP Update Page 0-4 Section 0.2 Section 1 page revision status SARP Update Page 0-7 Section 0.2 Table item: 1C-7975 Issue status raised to D Maximum vertical gap dimension added.

Page 0-7 Section 0.2 Table item: PCS 038 Issue status raised to K.

Revised definition/specification for CT-6.

Page 0-7 Section 0.2 Section 2 page revision status Section 3 page revision status SARP Update Page 0-8 Section 0.2 Section 4 page revision status Page 0-9 Section 0.2 Section 5 page revision status Section 6 page revision status Section 7 page revision status Section 8 page revision status SARP Update Section 1 - General Information Page 1-31 Tables 1-3-6, rows 6 and 8 Reference to contents limits changed to energy band limits.

Revised definition of CT-6 contents, based on energy band limits.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 28 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 17 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Page 1-39 Table 1-4-6 Table previously listed dominant dose contributing nuclides.

Revised definition for certificate.

Section 2 - Structural Evaluation Throughout the Section Page revision status only - no changes to text SARP Update Section 3 - Thermal Evaluation Throughout the Section Page revision status only - no changes to text SARP Update Section 4 - Containment Evaluation Throughout the Section Page revision status only - no changes to text SARP Update Page 4-1 Section 4.1, first sentence Reference to Figure 4-3 deleted Correct file reference error, Figure 4-3 was deleted in Rev 15 Page 4-4 Last para Reference corrected to Figure 4-3 Figures renumbered - was Figure 4-4, but preceding Figure was deleted.

Page 4-5 Figure 4-4 Renumbered Figure 4-3 Rev 15 update deleted previous Figure 4-3: word automatically updates references.

Section 5 - Shielding Evaluation Throughout the Section Page revision status only - no changes to text SARP Update Page 5-1 Contents Page number corrected for section 5.2 Page number field update Section 6 - Criticality Evaluation Throughout the Section Page revision status only - no changes to text SARP Update Section 7 - Package Operations Throughout the Section Page revision status only - no changes to text SARP Update

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 29 of 53 Summary of SARP Page Changes and Supporting Document Changes for Rev 17 Note: All changes to the SARP from the previous revision are shown in the Compare documents provided for each Section.

SARP Page or Doc Location Change Reason for Change Section 8 - Acceptance Tests and Maintenance Program Throughout the Section Page revision status only - no changes to text SARP Update Page 8-13 Table 8-1, second column Correct references Corrupted in Rev 15 submission update.

NRC Questions and Croft Responses This section is provided to document all NRC Questions and Croft Responses.

Table 2 - Question and Response Matrix Table

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 30 of 53 Q#

Review Question Croft Response Changed Item RAIs Provided by email dated 30/10/2018 1.1 Revise the free volume description in safety analysis report (SAR) Table 1-3-6.

In SAR Table 1-3-6, the applicant states that the product container and spacers shall be so designed as to leave a free volume of 225 cc within the [containment vessel] cavity. This statement neither identifies the free volume if the thorium target were shipped without a product container, as Table 1-3-6 allows, nor is consistent with the free volume description in proprietary calculation CS2018/01.

This information is necessary to satisfy the requirements in Title 10 of the Code of Federal Regulations (10 CFR) 71.33(a).

The volume of the cavity of the containment vessel - as specified in drawing 1C-7940 and identified in Figure 1-1c - is 450 cc. The volume of the jar, spaces and packing has been calculated as nominally 68 cc. Therefore, the free volume of the CV carrying the thorium target in the jar and packed with spacers is nominally 382 cc.

The free volume used in calculation CS 2018/01 has been conservatively specified as 225cc.

The text in the SARP in Table 1-3-6 has been edited to clarify the free volume.

SARP Table 1-3-6

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 31 of 53 2.1 Correct and revise, if necessary, the pyrophoric description of the proposed contents in SAR Table 1-3-6.

SAR Table 1-3-6 states The are not pyrophoric. (ADAMS Accession No. ML18136A487) The applicant confirmed that the statement should read The contents are not pyrophoric.

(ADAMS Accession No. ML18226A238) However, the U.S.

Department of Energy Handbook, Primer on Spontaneous Heating and Pyrophoricity, FSC-6910, identifies that thorium can be pyrophoric under certain conditions (e.g., a critical surface area in the presence of water). Therefore, the applicant needs to provide information which demonstrates that the proposed contents will not spontaneously combust.

This information is necessary to satisfy the requirements in 10 CFR 71.43(d).

The text in the SARP in Table 1-3-6 has been edited to say: The thorium disc is are not pyrophoric.

The thorium is in the form of a metal disk and the only moisture present is from the humidity in the air. Also, the materials are not in fine powder form and there is no source of ignition within the CV. LANL also reports that they have not observed any evidence of combustion in their handling of many thorium targets We conclude that contents in the CV are not capable of spontaneous combustion.

Section 1.2.2.1 4th para states Pyrophoric materials are permitted under the conditions specified. This para has been edited to provide justification.

It is noted that it has been previously accepted for Contents Types CT-1 and CT-2 that the contents of the CV may be pyrophoric.

SARP Section 1.2.2.1 4th para

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 32 of 53 2.2 Analyze the changes caused by radiation from the irradiated thorium target in the package containment vessel (CV).

SAR Section 2.2.3 only discusses the effects of radiation on package materials associated with the containment vessel. It does not discuss the impact of radiation on package components which are inside the containment boundary (e.g.,

the CV plug seal and the plastic product container) which are closer to the radiation source. In addition, since the applicant does not inert the CV cavity during loading operations, radiation from the thorium target may produce a combustible combination of gases due to the presence of water vapor. The applicant needs to provide a bounding assessment of (i) the radiation effects on components which are inside the containment boundary, and (ii) the amount of gas production due to radiolysis of moisture in the CV.

This information is necessary to satisfy the requirements in 10 CFR 71.43(d).

The responses to the questions are as follows.

Q(i) radiation effects Details of the packing within the CV for the thorium target have been added to SARP section 1.2.2.2.

The dose rate at the CV containment seal and the CV plug seal at time of packing (24 hr from EOB) have been calculated as 5.4E-7 Mrad/hr (0.0054 Gy/h) and 2.9E-4 Mrad/hr (2.9 Gy/h) respectively (see document 5183326, SARP Section 5.6.2).

The absorbed dose in a period of 1 year at the dose rate at 1 day from EOB at the CV containment seal and the 4109 insert seal would be 0.0047 Mrad (47 Gy) and 2.5 Mrad (2.5E4 Gy) respectively.

The Viton containment seal would not be damaged by 0.0047 Mrad - see Parker catalogue which indicates concern for doses of 10 Mrad.

The Viton CV plug seal would not be significantly damaged by 2.5 - see Parker catalogue which indicates concern for doses of 10 Mrad.

The plastic jar (if used instead of a metal tin) carrying the thorium target would have similar dose rates to the CV plug seal. The plastic would not be expected to be damaged by the calculated max dose of 2.5 Mrad.

In practice the absorbed doses would be much less calculated due to the decay of the radioactive contents which reduces to ~12% after 4 days.

(from 1 day after EOB).

SARP section 2.2.3

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 33 of 53 SARP Section 2.2.3 has been edited to address the above issues (new 7th para) and 4.1 (at the end of this section).

Q(ii) gas production due to radiolysis The maximum pressure that could arise from gas production due to radiolysis of moisture in the CV has been added to SARP section 3.3.2 [MNOP]

with reference to new calculation CS 2019/02 (ref Section 3.5.2) which shows that the pressure increase if the moisture was fully dissociated would be 0.02 bar. In practice full dissociation would not occur and there the pressure increase is regarded as negligible.

Calculation CS 2019/02 also shows that the maximum hydrogen produced would be ~ 0.2%

which is below the level of concern for detonation/deflagration.

SARP Sections 3.3.2 CS 2019/02

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 34 of 53 2.3 Demonstrate that the thorium target transportation configurations will not significantly increase external surface radiation levels.

The applicant states in SAR Table 1-3-6 that the thorium target may be shipped in a product container. However, a proprietary drawing submitted by the applicant shows a configuration in which the thorium target is encased in Inconel and shipped outside of a product container. It is understood that Inconel may be susceptible to embrittlement by proton irradiation. For example Carsughi et al. (1999) investigated Inconel 718 irradiated with 800 MeV protons, and found that the mechanical properties of Inconel 718 degraded after approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of irradiation at dose rates of 0.57 - 0.78 Sv/hour. If Inconel embrittlement occurs due to proton bombardment, normal conditions of transport (NCT) could damage the Inconel housing allowing either pieces of Inconel or pieces of thorium to relocate and produce increased radiation levels.

This information is necessary to satisfy the requirements in 10 CFR 71.43(f).

The text in the SARP in Table 1-3-6 and SARP Section 7.1.4 has been edited to clarify the packing for the thorium target in cut pieces in a jar as below.

The jar is robust and located by spacers - see Fig 1-7 added to SARP Section 1.2.2.2. This configuration prevents significant variation in the external radiation levels due to movement of the thorium.

Options for the jar are specified in SARP in Table 1-3-6 as commercial items may become unavailable. The jar may be plastic or metal.

Note that it is no longer proposed to ship a thorium target in an Inconel housing.

SARP in Table 1-3-6 and SARP Section 7.1.4

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 35 of 53 3.1 Clarify what is the maximum decay heat for content type CT-6, and provide NCT and HAC thermal evaluations for content type CT-6 if applicable.

Page 3-4 of the SAR states The package temperatures for Contents Type CT-6 (thorium target located at mid height of the CV cavity) would be bounded by those calculated for the higher maximum heat output of 30 W, as determined for the Inserts.

This gives the impression that the Contents Type CT-6 have a lower decay heat which is inconsistent with SAR Table 1-3-6 that provides the maximum decay heat of 30 W for the new contents. Also, page 17 of SARP Update Matrix for Thorium Target (CTR 2018/01) states that the heat output is less than 1 W which shows another inconsistency in the application. The staff needs this information to determine that predicted temperatures are below allowable limits for all package components.

This information is needed to determine compliance with 10 CFR 71.33(b)(7), 71.71(a), 71.71(c)(1), and 71.73(c)(4).

Revised SARP Table 1-4-6 gives the calculated heat output for the contents as 0.036 W.

Table 1-3-6 [Contents Type CT Thorium Target] has been revised to a bounding limit of

<1W which is consistent with the heat output given in Table 1-4-6.

The package has been assessed as satisfactory for 30 W and therefor detailed assessment for the thorium target emitting <1W is deemed unnecessary.

Table 1-4-6 SARP Table 1-3-6

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 36 of 53 5.1 Provide justification for using Ac-225 activity to define the content nuclides for CT-6 (activated thorium) within SAR Table 1-3-6.

Although many radionuclides are present, Table 1-3-6 only provides Ac-225 activity limits for the activated thorium content.

The applicant explains its intent by the statement in Appendix B of SARP Update Matrix for Thorium Target. which states: It is proposed that only the activity of Ac-225 (being the principal radionuclide of interest) be reported on the shipping labels and documentation and the there is no need to the shipper to establish that the limit for the radionuclides calculated to be in the thorium target are less than specified limits.

Section 2 of the shielding assessment (Document 5163778-HS-REP-001) states: The 3977A Type B SAFKEG-HS package is required to contain a thorium target consisting of a radioactive thorium disc surrounded by a thin Inconel housing. The source contains a host of radionuclides present in both the thorium disc and the Inconel housing. These radionuclides are listed in Table 7-1 and were provided by Reference [1].

The applicant needs to demonstrate the nuclide profile and activity used is bounding of any Inconel incased proton activated thorium target that would produce 7.9 GBq (0.2 Ci). Specifically the staff requests the following:

1. Provide Reference 1 from Document 5163778-HS-REP-

001,

2. Justify that the activation and decay assumptions from SAR Section 5.5.4.3 are bounding for all proton activated thorium

contents,

3. Justify how the radionuclide profile was determined and state if daughter products of radionuclides were considered, and

4. Justify the amounts of thorium, inconel and impurities (e.g.,

cobalt within the Inconel) used to simulate the target are bounding.

The responses to the questions are as follows.

Q1 Document 5163778 is no longer relevant as the shielding assessment has been revised and document 5163778 replaced by document 5183326 (see SARP Section 5.3.1 and Section 5.6.2).

Q2 The activation of the thorium target calculated using the FLUKA code is given in BNL report C-A/BLIP/001 (ref SARP Section 5.3.1) which lists all individual radioisotopes (498 isotopes in total) determined by the code at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> decay time following the target irradiation (otherwise known as 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> End of Beam (EOB)). The activity (Bq) for each isotope is also provided.

Q3 See Q2. Daughter products of radionuclides are included.

Q4 The target is thorium only - the Inconel housing is not to be shipped. The target assumed in the BNL FLUKA calculation is 100% Th-232 which is the composition of the actual target.

SARP Sections 5.3.1, and Section 5.6.2

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 37 of 53 This information is needed to verify compliance with 10 CFR 71.33(b)(1), 71.47 and 71.51(a)(2).

5.2 Justify the use of nominal dimensions for the shielding components.

The staff compared the dimensions shown in Tables 7-2 and 7-3 of the shielding assessment (Document 5163778-HS-REP-001) to that of the drawings 0C-7942, 0C-7943 and 1C-7946. The staff finds use of nominal dimensions non-conservative. The staff requests that the applicant provide additional justification demonstrating that using nominal rather than minimum dimensions does not cause the package to exceed regulatory dose rate limits in 10 CFR 71.47 and 10 CFR 71.51(a)(2). Although the applicant addressed this item during initial issuance of the certificate, the staff does not find that the previously submitted uncertainty analyses address this item for the following reasons: (1) the content and analysis method are completely different from that of the initial approval, and (2) the staffs acceptance of the previous uncertainty analysis (ADAMS Accession No. ML14092A086) was based on conservatisms and margins to regulatory limits associated with the application for initial issuance of the certificate. The current analysis has removed some of those conservatisms (e.g., the source is no longer a point source and the cork material is now being credited within the analysis). Further, since the staff did not locate the dose rates (see RAI 5-7), the staff cannot determine if there is sufficient margin to the regulatory dose rate limit to compensate for this uncertainty.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

New shielding Assessment 5183326 assesses dose rates at 24 h EOB.

All relevant dimensional tolerances (as provided in the CAD drawings) have been carefully considered and the dimensions have been adjusted, within the tolerances, to ensure the modelled geometry gives conservative, bounding dose rates. In practice this means that dimensions are adjusted to reduce distances and shielding between the sources and outside surface of the package.

SARP Section 5.3.2 (penultimate paras) and Section 5.5.4.3 have been edited to reference the new shielding Assessment 5183326.

SARP Sections 5.3.1, 5.5.4.3 and 5.6.2

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 38 of 53 5.3 Discuss how the effects from NCT and HAC were incorporated into the shielding evaluation.

The applicants shielding evaluation does not discuss effects to the package due to NCT and HAC. However, SAR Section 2.7.8 indicates that there is deformation to the package as a result of the side puncture test and the 10.2 meter drop. In addition, both SAR pages 3-10 and 3-11 state: Under HAC conditions the cork reaches a maximum temperature of 788oC. Cork ablates under high temperatures and leaves a low density carbonaceous layer which provides insulation equivalent to still CO2. The applicant needs to discuss how these effects are accounted for within the shielding evaluation. Although the applicant has addressed this item during initial issuance of the certificate, the staff does not find that the previously submitted uncertainty analyses address this item for the following reasons: (1) the content and analysis method are completely different than that of the initial approval, and (2) the staffs acceptance of the previous uncertainty analysis (ADAMS Accession No. ML14092A086) was based on conservatisms and margins to regulatory limits associated with the application for initial issuance of the certificate. The current analysis has removed some of those conservatisms (e.g., the source is no longer a point source and the cork material is now being credited within the analysis). Further, since the staff did not locate the dose rates (see RAI 5-7), the staff cannot determine if there is sufficient margin to the regulatory dose rate limit to compensate for this uncertainty.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

New shielding Assessment 5183326 assesses dose rates at 24 h EOB under the NCT (SARP Section 5.6.2). The relevant damage from the NCT test is an 8.06 mm dent in the package outer keg skin. This results in the surface of the package at the dent location effectively being closer (by 8.06 mm) to the centrally held source, this potentially increases the peak dose rates measured from the surface. In order to assess this in a bounding manner the entire outer steel dimensions of the package have been reduced by 8.06 mm in the shielding model.

The effect of the HAC drop tests are reported in the SARP in Section 5.2.2 which gives the effect of HAC as an 11 mm dent to the side of the package. This dent would cause a 5% increase in dose rate on the package which is not a significant increase from the NCT dose rates (a much larger increase is allowed by the regulations).

SARP Section 5.6.2

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 39 of 53 5.4 Clarify the minimum dimensions for both the activated thorium source and the Inconel housing and justify the dimensions used in the shielding evaluation.

Proprietary drawing No. 1C-7972, Packing for Thorium Target in Design No. 3978 - Sealed Plug, shows the dimensions of the activated thorium source as 57.15 mm in diameter by 0.37 mm thick. However, SAR Section 5.3.1 states that the source is nominally 60 mm x 5 mm. In addition to clarifying the dimensions of the activated thorium disc, the applicant needs to identify if these dimensions are exact, minimum or nominal and provide the tolerances for the activated thorium disc.

The size of the Inconel cladding for the thorium target is not specified in Drawing 1C-7972. Section 3.2.3 of the shielding assessment (Document 5163778-HS-REP-001) states that the source dimensions are a cylindrical disc of thorium with radius 3 cm and height 0.5 cm, surrounded by a 0.1 cm thick Inconel housing. These dimensions are roughly consistent with the source dimensions specified within the SAR; however, they are non-conservative compared to the source as specified in Drawing 1C-7972. Since they are larger and include the Inconel housing, this provides additional self-shielding. Since the Inconel housing is assumed to be present within the shielding evaluation, the applicant needs to justify that the source will retain its analyzed geometry and will not be separated from its Inconel housing under NCT or HAC additionally taking into consideration any Inconel embrittlement from the source radiation. The staff needs this information to determine if the amount of self-shielding assumed within the shielding evaluation is appropriate and conservative.

This information is needed to verify compliance with 10 CFR 71.33(b)(3), 71.47 and 71.51(a)(2).

The inclusion of an Inconel housing is no longer specified in the SARP.

New shielding Assessment 5183326 models the thorium target as dia 57.15 mm x 0.37 mm which is nominally the same as the dimensions used in the calculations using the FLUKA code as given in BNL report C-A/BLIP/001.

SARP Section 5.3.1 has been edited to give the correct dimensions for the thorium target (dia 60 mm x 0.37 +/- 0.025 mm) as specified in BNL report C-A/BLIP/001 (ref SARP Section 5.3.1 and Section 5.6.2).

SARP Section 5.3.1 and Section 5.6.2

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 40 of 53 5.5 Provide the distances from the package surface used to evaluate regulatory dose rates in 10 CFR 71.47 and 10 CFR 71.51(a)(2).

The staff was unable to locate the distances that the applicant used to evaluate the regulatory dose rate limits. The staff requires this information to be able to verify that the locations used for evaluating dose rates under NCT are consistent with the distances prescribed in 10 CFR 71.47(b) for exclusive use and 10 CFR 71.51(a)(2).

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

Additional analysis has been provided in SARP section 5.2.1 re dose rates under for exclusive use.

SARP Section 5.2.1 and Section 7.4 has been edited to require use of a pallet 750 mm high to space the package from the floor of the conveyance for Contents Type 6 - CT-6 for the Thorium target.

Shielding Assessment 5183326 (see SARP Section 5.6.2) assesses dose rates (given in Section 5.2.1) at:

Package Surface Outer Surface of Conveyance 2 m from Edge of Conveyance 1 m from Package Surface 1 m from Edge of Conveyance SARP Section 5.2.1 Section 7.4 SARP Section 5.6.2 Section 5.2.1 5.6 Provide a representative Monte Carlo N-Particle (MCNP) input and output file.

The applicant did not provide an MCNP input or output file. The staff uses these files to verify if package design information has been properly input into the code, to ensure that proper convergence is achieved and that the calculated dose rates from the output files agree with those reported in the application.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

Representative Monte Carlo N-Particle (MCNP) input and output files have been provided

[associated with the calculations in report 5183326 ref SARP Section 5.6.2].

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 41 of 53 5.7 Provide calculated dose rate levels.

SAR Table 5-15, Summary Table of package base external dose rates from MCNP calculations for the Nuclide Activities in LANL calculations for a typical target activated to produce 0.2 Ci Ac-225 states: See Atkins report 5163778-HS-REP-001-001 (Section 5.5.6). Neither the Atkins report nor the SAR has a Section 5.5.6. Column 12 in SAR Table 1-4-6 reported a maximum surface dose rate; however, this value exceeds the regulatory dose rate limit of 10 mSv/hr in 10 CFR 71.47(b)(1).

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

Shielding Assessment 5183326 (ref SARP Section 5.6.2) provides assessed dose rates.

Dose rate data has been added to SARP Section 5.2.1, Table 5-1 Table 5-15 in SARP Section 5.5.4.3 has been edited to reference the new report 5183326 with ref to location of full reference information given in the References in SARP Section 5.6.2.

SARP Section 5.6.2 SARP section 5.5.4.3 7.1 Revise steps 5 and 8 of SAR Section 7.1.4.

Steps 5 and 8 of SAR Section 7.1.4 do not direct the user to perform an action. If the information in these steps is important to package operations, the applicant should either revise steps 5 and 8 to direct the user what action to perform or reformat the information (e.g., provide the information as a Note). In addition, the information in step 8 associates 225 cc only with the use of spacers while with the information provided in Table 1-3-6 associates 225 cc with the use of spacers and a product container. If the applicant chooses to retain the information in step 8, the applicant needs to make the information in Table 1 6 consistent with the information in step 8.

This information is needed to verify compliance with 10 CFR 71.87(f).

SARP section 7.1.4 has been edited to movet Steps 5 and 8 (in SARP Rev 14) into the NOTES.

The 2nd note re leak testing has been edited for clarity.

The 3rd note re contents packing requirements has been edited to refer to details given in SARP Section 1.2.2.2 in Figure 1-7. The requirement for a free volume of 225 cc has been removed as this is ensured by the design of the packing specified in SARP Section 1.2.2.2 in Figure 1-7.

Steps 5 and 6 have been edited for clarity.

SARP section 7.1.4 SARP Section 1.2.2.2 in Figure 1-7

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 42 of 53 7.2 Clarify the instructions associated with inserts in the sealed split lid configuration.

SAR Sections 7.1.4, 7.2.4 and 7.3.3 each contain steps associated with inserts. However, the applicant did not provide insert drawings for the sealed split lid package configuration, and other SAR Sections do not discuss the use of an insert with the sealed split lid package configuration. Therefore, the applicant should either remove these steps, or if the applicant wishes to retain the flexibility to use inserts with the split lid configuration, the applicant should modify these instructions to identify under what circumstances they need to be performed.

This information is needed to ensure compliance with 10 CFR 71.87(f).

SARP section 7.1.4, 7.2.4 and 7.3.3 have been edited to clarify packing requirements for the thorium target.

RAIs provided by email October 25, 2019 and by letter dated October 31, 2019

[BV1]

5.1 Confirm that the maximum energy for each energy bin was used in the MCNP model for calculating dose rates.

The Atkins report 5183326-HS-REP-001-01 (ADAMS Accession No. ML19289A805) states that the photons were binned into energy groups. From the sample MCNP file provided on October 2, 2019 (ADAMS Accession No. ML19297E730), it appears that the energy used to simulate the energy group represented in this file (2-2.5 MeV) is the maximum energy of the group (2.5 MeV).

Confirm that the maximum energy for each group is modeled for every energy group allowed within the package. The staff is requesting this information to determine if the modeling of the gamma energy is conservative.

This information is needed to verify compliance with 10 CFR 71.33(b)(1), 71.47 and 71.51(a)(2).

The maximum energy for each energy bin was used in the MCNP model for calculating dose rates.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 43 of 53 5.2 State if the additional steel on the bottom of the CV plug was included in the model used to determine if dose rates are within regulatory limits and if so provide the dimensions used in the model.

Table 8-1 does not include the extra steel as part of the CV split lid configuration on the bottom of the CV plug. The staff requests that the applicant state if this was modeled in the shielding evaluation and how much steel it assumed. It appears to be present in some of the drawings in Section 9 of the Atkins report.

The staff needs this information so that it can compare the dimensions with those in Drawing 1C-7947 to determine if it was modeled in a conservative or accurate way.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

The steel is included on the bottom of the CV plug, this has a thickness of 24.4 mm.

There is a hole in the centre bottom of the plug as a radius of 4 mm and a depth of 12 mm. See figure below:

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 44 of 53 5.3 Provide additional information justifying that the effect of vibration normally incident to transport does not result in source relocation.

As part of first round RAI 5-3, the staff requested that the applicant provide information on how the effects from NCT and HAC were incorporated into the shielding evaluation. The staff found that the information provided does not fully address the question as it only addressed the free drop test results. The staff is requesting that the applicant discuss the effects of vibration normally incident to transport as specified in 10 CFR 71.71(c)(5) on the jar/tin that contains the thorium source and justify that the source cannot come out of the configuration in which it is analyzed. Although the spacers should keep the lid from opening based on gravity if shipped upright, if not shipped upright there could be space between the spacers and the walls of the cavity that could allow relocation of the source.

The entire height of the jar and spacer configuration is 110mm from Drawing 1C-7975 as compared to the height of the cavity of 113.4mm of the HS-55X113 Insert in Drawing 2C-8094. Based on the Studsvik event from 2001 (https://inis.iaea.org/collection/NCLCollectionStore/_Public/37/08 8/37088552.pdf), the staff is concerned with the possibility of small sources migrating out of the content holder due to vibration normally incident to transport. The staff requests that the applicant include a description of the measures that would prevent the small source from escaping from the jar/tin or the design features of the jar/tin that would prevent this from happening.

This information is needed to verify compliance with 10 CFR 71.47 and 71.71(c)(5).

Effects of vibration normally incident to transport The packing arrangements for the Thorium target CT-6 were specifically designed to prevent the target pieces from getting out of the jar of the primary packing [jar] and Insert Design No 2901 and therefore not be able to enter the space around the shielding plug, as happened in the Studsvik Incident for Croft package 2835A, by the provisions as follows.

The thorium target pieces will be packed in a jar as shown on Figure 1-7 of the SARP Rev 16. The jar will be packed within stainless steel insert Design No. 4109 [as shown on Figure 1-5e of the SARP Rev 16] using the spaces as shown in Figure 1-7. The stainless steel insert Design No.

4109 carrying the thorium target pieces will be located in the cavity of the CV shown in Figure 1-2b of the SARP Rev 16.

The thorium discs will be prevented from all but small radial movement at the bottom of the jar by the knit wire packer that fills the free space between the thorium pieces and the lid of the jar.

This will be effective in whatever orientation the package is shipped.

The lid of the jar is held in place so that it cannot release its contents by the spacers which would prevent the lid of the jar being loosened by > 6.1 mm by virtue of the axial space in the cavity of the insert Design No. 4109 being not > 6.1 mm based on worst case tolerances, and the depth of the lid being > 6.1 mm [actually > 10 mm or more].

The lid of the insert Design No. 4109 cannot come off by virtue of the axial space in the cavity of the CV above the insert, based on worst case

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 45 of 53 tolerance is < 6.6 mm - the depth of the lid being

> 6.6 mm [actually > 19 mm].

The requirements for proper packing of the thorium discs, jar and insert Design No. 4109 are specified in Table 1-3-1 in Section 1 of the SARP and para 7.1.4 in Section 7 of the SARP.

Although it is possible that vibration under normal conditions of transport could loosen the closure of the jar, the lid cannot come off by virtue of the axial space in the cavity of the insert Design No.

4109 being too small.

Also, it is deemed unlikely that vibration under normal conditions of transport could loosen the closure of the insert Design No. 4109 by virtue of its design incorporating a seal which should resist movement of the lid if correctly tightened as required on assembly [para 7.1.4 6) in Section 7 of the SARP], and furthermore the lid cannot come off by virtue of the axial space in the cavity of the CV above the insert being filled with a silicone sponge disk to reduce movement and dampen any vibrational impacts.

5.4 Provide the cross section library used within the MCNP code to calculate the dose rates.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

The ENDFB-VII.1 cross section library was used.

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 46 of 53 5.5 Provide additional information on the tallies used to calculate dose rates.

Section 4.1.2 of the Atkins report states that dose rates were assessed in a mesh arrangement for purposes of determining the peak dose rate locations. However, the staff did not locate a description of the tallies used to calculate compliance with regulatory dose rate limits. The staff requests that the applicant provide a summary of the tally type and size in order for the staff to determine if the tallies are sufficiently small to be able to evaluate a maximum dose rate and not an average dose rate.

The scoping assessments as described in Section 4.1.2 used FMESH tallies for both the Stack and Disc arrangements. For each arrangement, the FMESH tallies were positioned at the top, bottom and either side of the package.

Each mesh element is 1 cm3.

See figures below:

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 47 of 53

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 48 of 53 5.6 Provide the location used to evaluate the bottom surface dose rate.

The staff requests that the applicant confirm if the reference surface on which the package surface dose rate is evaluated is the annular hole on the bottom of the SAFKEG, or whether it is flush with the bottom rims and confirm all other distances (0.75 meter conveyance, 1 meter and 2 meter). There is not enough information from Figure 9-10 from the Atkins report, 5183326-HS-REP-001-01 (proprietary report, ADAMS Accession No. ML19218A020) for the staff to determine on which the surface dose is calculated and from which the other distances are referenced.

This information is needed to verify compliance with 10 CFR 71.47 and 71.51(a)(2).

There are 5 positions, the surface and 1 m are taken from the SAFKEG bottom surface inside the annular rims. The conveyance tallies are measured from the bottom of the rims.

Surface Bottom surface Bottom Surface Tally:

Within annular hole of SAFKEG. Precise position of Tally face is 0.5 cm from the bottom surface of the SAFKEG (within the annular hole).

100 cm 1 m 1 meter: 1 m from bottom surface of the SAFKEG - within the annular hole.

Conveyance + 0 cm (75 cm) 0.75 m conveyance 0.75 m from the bottom rims.

Conveyance + 100 cm (175 cm) 1 m conveyance 1.75 m from the bottom rims Conveyance + 200 cm (275 cm) 2 m conveyance 2.75 m from the bottom rims

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 49 of 53 Appendix A New or edited Supporting Documents provided in the SARP from Rev 13 Supporting Documents provided in the SARP at Rev 14 Table 3A - New or edited supporting documents provided in the SARP Related SARP Section or Doc Document Reference Title Section 1 - General Information Documents in Section 1.3.3, Licensing Drawings Addition 1C-7940 A

Cover sheet for Safkeg-HS Design No. 3977A - Sealed plug Addition 0C-7941 A

Safkeg-HS Design No. 3977A - Sealed plug Addition 0C-7942 A

Keg Design No. 3977 - Sealed plug Addition 0C-7943 A

Cork set for Safkeg-HS - Sealed plug Addition 1C-7944 A

CV Design No. 3978 - Sealed plug Addition 1C-7945 A

CV lid - Sealed plug Addition 1C-7946 A

CV body - Sealed plug Addition 1C-7947 A

Containment vessel plug - Sealed plug Documents in Section 1.3.4 Supporting Documents Updated for Rev 15 PCS 038 J

Package Contents Specification for Safkeg-HS - Package Design No 3977A Section 5 - Shielding Evaluation Documents in Section 5.6.2 Deleted for Rev 15 Atkins report:

5163778-HS-REP-001-001 Iss 001 HS Container Shielding Assessment with Thorium Target

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 50 of 53 Supporting Documents provided in the SARP at Rev 15 Table 3B - New or edited supporting documents provided in the SARP Related SARP Section or Doc Document Reference Title Section 1 - General Information Documents in Section 1.3.3, Licensing Drawings Addition 1C-7975 B

Packing for thorium target in Design No 3978 Documents in Section 1.3.4 Supporting Documents Update PCS 038 J

Package Contents Specification for Safkeg-HS - Package Design No 3977A Section 5 - Shielding Evaluation Addition CS 2018/01 A

SAFKEG-HS 3977A - Gas contents limit for leaktight condition - Thorium target Documents in Section 5.6.2 Addition BNL report C-A/BLIP/001 January 2019 Activation of Th-232 target using FLUKA simulation code Addition Atkins report:

5183326-HS-REP-001 01 Shielding Assessment of the 3977A SAFKEG Transport Package Type B(U) with Thorium Target Source

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 51 of 53 Supporting Documents provided in the SARP at Rev 16 Table 3C - New or edited supporting documents provided in the SARP Related SARP Section or Doc Document Reference Title Section 1 - General Information Documents in Section 1.3.3, Licensing Drawings Modified 1C-7940 C

Cover sheet for Safkeg-HS Design No. 3977A Modified 0C-7941 C

Safkeg-HS Design No. 3977A Modified 1C-7944 C

CV Design No. 3978 Modified 1C-7946 C

CV body Modified 2C-8094 B

HS-55x113-ss SS insert Design No 4109 Modified 1C-7975 C

Packing for Thorium Target in Design No. 3978 New 2C-6920 A

Silicone Sponge Rubber Disc Supporting Documents provided in the SARP at Rev 17 Related SARP Section or Doc Document Reference Title Section 1 - General Information Documents in Section 1.3.3, Licensing Drawings Modified 1C-7975 D

Packing for Thorium Target in Design No. 3978 Documents in Section 1.3.4 Supporting Documents Update PCS 038 K

Package Contents Specification for Safkeg-HS - Package Design No 3977A

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 52 of 53 Appendix B Contents Type CT Thorium Target This appendix is provided to explain the approach taken for specifying the contents type CT-6 which is for a radioactive thorium target.

The radioactive content of the thorium target arises from proton irradiation at BNL with proton beam energy range of 191 MeV and the beam current of 165 A to produce nominally 7.964E+09 Bq (0.215 Ci) Ac-225. The target is allowed to decay for 24hour after EOB to allow short halflife radionuclides to decay and to reduce the radiation dose from the target - the activity of the Ac-225 will be nominally 7.46E+09 Bq (0.2 Ci) Ac-225 at that time. The activation of the thorium target is given in BNL report C-A/BLIP/001 (SARP Section 5.6.2) and the associated spreadsheet which gives details at 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after EOB for the 498 isotopes in total produced by the activation.

Monte Carlo shielding calculations, for all the radionuclides present at EOB in the activated thorium target, are reported in Atkins report 5183326-HS-REP-001 (Section 5.6.2). The calculations determine the external dose rates for the package.

Under NCT and HAC, it is assumed that the contents (thorium target) are located nominally in a fixed position in the CV in and insert, a jar with knit wire packing and the spacers above and below the jar. Containment is provided by the inner seal of the double O-ring seal system provided by the CV. Confinement within the CV cavity is ensured by the seal in the insert.

The Monte Carlo shielding calculations for NCT, as reported in Atkins report 5183326-HS-REP-001 (SARP Section 5.6.2), provide dose rate information on a per photon/s basis for 15 energy groups at various distances from the transport package. This information is used to determine the dose rates from each nuclide from the radioactivity information at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from EOB. The results of the dose rate calculations are provided in SARP Section 5.1.1.

The dose rate calculations as reported in Atkins document 5183326 were carried out for the contents carried in the CV without an insert. As the packing is similar with the required insert (HS-55x113-SS ), the dose rates with the insert would be slightly lower than without the insert.

The shielding calculations show that the dose rate on the external surface of the package will exceed the non-exclusive use regulatory limit of 2 mSv/h but will be within the Exclusive Use limits for a shipment. The calculated maximum package surface dose rate for the activated thorium target is 8.18 mSv/hr at 1 day from EOB: an approximate calculation has shown that this dose rate reduces to about 2 mSv/hr at 2 days from EOB.

The dose rates are not significantly affected by HAC: this is explained in SARP Section 5.1.2.

The BNL FLUKA calculations (BNL report C-A/BLIP/00, SARP Section 5.6.2) showed that 498 nuclides with activity greater than 1.E09 of the total activity after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> cooling time are produced by the activation: it is assumed that the contribution to dose rate for nuclides with activity less than 1.E09 of the total activity after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> cooling time is negligible. All 498 nuclides are included in the Atkins shielding calculations (Atkins report 5183326-HS-REP-001,

SAFKEG-HS 3977A Docket Number 71-9338 CTR 2018/01 Issue D Page 53 of 53 SARP Section 5.6.2), however, on sorting the table of Package Surface Dose Rate Results (Table A-6 in Atkins report) by dose rate for each nuclide only 17 nuclides contribute > 1% to this dose rate: the package surface dose rate for these 17 nuclides is 7.1 mSv/h with the same rate for all 498 nuclides is 8.2 mSv/h. In order to simplify the reporting, only the 17 nuclides that contribute

> 1% to the package surface dose rate (+ Ac-225 which has a very low contribution of <1E-4% to the package surface dose rate ) are listed in PCS 038 and SARP Section 1, Table 1-4-6.

However, the dose rates reported in SARP Section 5.5.1 are for all 498 nuclides.