ML20207K706

Comment on Proposed Rule 10CFR72, List of Approved Spent Fuel Storage Casks

ML20207K706
Person / Time
Site:	07201008
Issue date:	03/12/1999
From:	Gilligan B HOLTEC INTERNATIONAL
To:	Hoyle J NRC OFFICE OF THE SECRETARY (SECY)
References
FRN-64FR1542, RULE-PR-72 64FR1542-00003, 64FR1542-3, TAC-L22019, NUDOCS 9903170279
Download: ML20207K706 (29)

Text

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Holtec Center,555 Lincoln Drive West, Marlton, NJ 08053 HOLTEC Telephone (609) 797-0900 Fax (609) 797-0909 iN T E R N A TIO N A L BY OVERNIGHT MAIL o

... r March 12,1999 DOCKET NUMBERm

'g PROPOSED RULE rn #

g g

Mr. John C. Hoyle

(&#FR/642)

(5 Secretary of the Commission Ui M

U.S. Nuclear Regulatory Commission 4

y 11555 Rockville Pike a

Rockville, MD 20852 d

Attention: Rulemakings and Adjudications Staff

Subject:

Proposed Rulemaking to 10 CFR 72.214, List of Approved Spent Fuel Storage Casks (Federal Register Vol. 64, No. 6 - January 11, 1999), Holtec Public Comment Letter No. 5014-1.

References:

1.

Docket 72-1008, TAC L22019 2.

Holtec Letter, B. Gilligan to NRC, M. Delligatti, dated February 17,1999 Holtec International and the group of utilities comprising the Holtec Users' Group (HUG) have performed a detailed review of the above-referenced rulemaking for the HI-STAR 100 System spent fuel storage cask design, including the supporting Topical Safety Analysis Report (TSAR),

Safety Evaluation Report (SER), and Certificate of Compliance (CoC). This review has resulted in a number of comments we feel are necessary to correct, clarify, or enhance the usefulness of

/

the information.

1 The HUG met in Savannah, Georgia on March 4 and 5"' to review the comments and provide th direction for submitting the comments to the NRC. Holtec was directed by the HUG to submit the purely editorial comments under separate correspondence from the non-editorial comments. to this letter is that set of editorial comments for your review and disposition.

Each comment is uniquely numbered with the affected document and section noted with the proposed correction and the reason for the change. Please note that all editorial corrections to the TSAR document will be made by Holtec and included in conforming Revision 10 to the HI-STAR TSAR to be submitwd within 90 days of the issuance of the final CoC.

Additionally, Attachment 2 to this letter provides a list of enhancements and clarifications to the HI-STAR 100 design and drawings which implement the lessons learned from the HI-STAR 100 prototype program. These same enhancements, adjusted for differences in the applications, were also provided via letter to the NRC for the transportation Certificate of Compliance being prepared under Docket No. 71-9261, TAC L22085 (P.cf. 2). Upon NRC concurrence with these 9903170279 990312 PDR PR 72 64FR1542 PINT jQ 9

b tioltec Center,555 Lincoln Drive West, Marlton, NJ 08053 HOLTEC Telephone (609) 797-0900 Fax (609) 797-0909 INTERNATIONAL Mr. John C. Hoyle U.S. Nuclear Regulatory Commission March 12.1999 Page 2 of 3 changes, Holtec will revise the affected documents as stated in Attachment 2 and include these enhancements in Revision 10 to the Hi-STAR 100 TSAR.

Please contact me at (609) 797-0900, extension 668 if you have any questions or require additional information Sincerely, Bernard Gilligan Project Manager HI-STAR /HI-STORM Licensing Document I.D. 5014280 Cc:

Mr. Mark Delligatti, USNRC (w/ attach.)

Approvals

.K/w Bffan Gutderman

/W 0 G W i k K. P. Singh, Ph.D., P.E.

Licensing Manager President and CEO Client Distribution (w/ attach.)

Mr. David Bland Southern Nuclear Operating Company Mr. Ken Phy New York Power Authority Mr. J. Nathan Irech Commonwealth Edison Dr. Max DeLong Private Fuel Storage Mr. Stan Miller Yankee Atomic

de Holtec Center,555 Uncoln Drive West, Marlton, NJ 08053 HOLTEC Telephone (609) 797-0900 Fax (609) 797-0909 INTERNATIONAL Mr. John C.11oyle U.S. Nuclear Regulatory Commission March 12,1999 Page 3 of 3 Client Distribution (w/o attach.)

Mr. Bruce Patton Pacific Gas & Electric Mr. Rodney Pickard American Electric Power Mr. David Larkin Washington Public Power Supply System Mr. Eric Meils Wisconsin Electric Power Company Mr. Paul Plante Maine Yankee Atomic Power Company Mr. Stan Miller Vermont Yankee Corporation Mr. Jim Clark Southern California Edison Mr. Ray Kellar Entergy Operations-Arkansas Nuclear One Mr. Joe Andrescavage GP~UN - Oyster Creek Nuclear Power Station Mr. Ron Bowker IES Utilities Mr. William Swantz Nebraska Public Power District l

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I Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 1 of 9 Ill STAR 100 RULEMAKING EDITORIAL COMMENTS Comment No.: 1 Section:

Certificate of Compliance -Item 5.a Comment:

Replace the sentence beginning "Any MPC-68 containing..." with the following: "Any MPC-68 loaded with material classified as FUEL DEBRIS in accordance with the technical specifications is designated as MPC-68F."

Reason:

Clarification of MPC-68F definition.

Comment No.: 2 i

Section:

Certificate of Compliance - Item 5.b, third paragraph, sixth sentence Comment:

Replace " seal-welded" with " strength-welded".

Reason:

Clarification. These welds are analyzed as load-bearing welds, unlike seal welds.

Comment No.: 3 Section:

Certificate'of Compliance - Item 5 Comment:

Item c " Drawings" and item d " Basic Components" were deleted between the draft and preliminary version of the CoC. They should be restored, including the following correction: Item c should refer to TSAR Section 1.5 for the location of the Design Drawings.

Reason:

Restore deleted information.

I Comment No.: 4 Section:

Certificate of Compliance - Item 7 -

Comment:

Replace " purchase" with " procurement" Reason:

Grammatical change.

Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 2 of 9 III-STAR 100 RULEMAKING EDITORIAL COMMENTS Comment No.: 5 Section:

Technical Specifications - Table of Contents Comment:

Revise the. Title of LCO 3.11 to read: "MPC Cavity Vacuum Drying Pressure" Reason:

Correct LCO title.

Comment No.: 6 i

Section:

Technical Specifications - 1.1 Comment:

Add "(DFC)" after " DAMAGED FUEL CONTAINER" in the Term" column.

Reason:

Correct omission.

Comment No.: 7 Section:

Technical Specifications - 1.1 Comment:

Delete the existing definition for Independent Spent Fuel Storage Installation (ISFSI) and replace with the following:

"An ISFSI is a complex designed and constructed for the interim storage of spent nuclear fuel and other radioactive materials associated with spent fuel storage."

Reason:

To be consistent with the ISFSI definition in 10CFR72.3 (as modified by current proposed rulemaking under SECY 98-171).

Comment No.: 8 Section:

Technical Specifications - 1.1 Comment:

In the definition of TRANSPORT OPERATIONS, after " include all licensed..." add " activities performed on -n SFSC loaded with one or more

Mr. John C. Ifoyle U. S. Nuclear Regulatory Commission Document ID 5014280 AttacL ; nt 1 Page 3 of 9 III STAR 100 RULEMAKING EDITORIAL COMMENTS fuel assemblies when it is being moved to and from the ISFSI." After the second " suspended from", add "or secured on."

Reason:

Add information from the TSAR definition and correct omission.

Comment No.: 9 Section:

Technical Specifications - 1.3, DESCRIPTION section, first paragraph Comment:

Change "SFCS" to "SFSC."

Reason:

Correct typographical error.

_ Comment No.: 10 Section:

Technical SpeciEcations - 2.1.2 Comment:

Replace "(zone year)" with "(2 one year)".

Reast a:

Correct typographical error.

Comment No.: 11 Section:

Technical Specifications - Table 2.1-1, Item i Comment:

There appears to be page break after item I.A.b which does not belong there.

Reason:

Correct format.

Comment No.: 12 Section:

Technical Specifications - Table 2.1-3 Comment:

Delete "(Note 3)" in column header for fuel assembly Array / Class 9X9A and 10X10A. Capitalize the "N" in " Note" in columns 8X8D sad 9X9A. Add

" fuel" after " total" in Note 3 on page 2.0-22. Add ">" before the number for water rod thickness in column 9X9C. Add "(Note 3)" under the number of fuel rods in column 10X10A.

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Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 i

Page 4 of 9 ill-STAR 100 RULEMAKING EDITORIAL COMMENTS Reason:

Correct format and typographical errors.

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Comment No.: 13 Section:

Technical Specifications - Section 4.5.1.2.2 Comment:

Add a zero in front of ".Olg/cm.

2 Reason:

To be consistent with other numbering.

l Comment No.: 14 Section:

Technical Specifications - Section 4.7 Comment:

In the sixth item, replace "OVERRPACK" with "OVERPACK." Add the following to the end of the seventh and eighth items: (for which a mock-up may be used)"

Reason:

Correct typographical error and provide words to support the fact that that the dry run of these activities need not be performed with spent fuel in the MPC/OVERPACK.

.C9mme. nt No.: 15 Section:

Technical Specification Bases - B 3.0, page B 3.0-1 Comment:

In the first section, replace "LCOS" with "LCOs." In the Bases for LCO 3.0.2, indent the "a" and "b" to align with the text above and below. Change "SFCS" to "SFSC" in the next-to-last sentence on the page.

Reason.

Correct format and typographical errors.

Comment No.: 16 Secti<m:

Technical Specification Bases - B 3.0, page B 3.0-2 and B3.0-3 h

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Mr. John C. Iloyle U. S. Nuclear Regulatory Commission 1

Document ID 5014280 Page 5 of 9 Ill. STAR 100 RULEMAKING EDITORIAL COMMENTS l

Comment:

In the Bases for LCOs 3.0.4 and 3.0.5, indent the "a" and "b" to align with the text above and below. In Bases for LCO 3.0.4, item a, replace "SFCFC" with "SFSC". In item b, replace "SFCS" with "SFSC." In the Bases for LCO 3.0.5, item b, replace "LCOS" with "LCOs."

Reason:

Correct typographical errors.

Comment No.: 17 Section:

Technical Specification Bases - B 3.0, page B 3.0-5 f

Comment:

In the first section, last sentence, replace "This will allow operation to i

proceed...." with "This will allow SFSC activities to nroceed...."

Reason:

Correct terininology.

Comment No.: 18 Section:

. Technical Specification Bases - B 3.1.7, page B 3.1.7-1 Comment:

In the LCO section, last sentence, replace "byt he": with "by the".

Reason:

Correct typographical error.

Comment No.: 19 Section:

Technical Specification Bases - B 3.1.7, page B 3.1.7-2 Comment:

In the ACTIONS section, replace "none" with "neither" and replace "one of the three" with "either of the."

Reason:.

Correct bases to match changes in the LCO.

Con' ment No.: 20 Section:

Technical Specification Bases - B 3.1.7, page B 3.1.7-2

t Mr. John C. Iloy!c U. S. Nuclear Regulatory Commission Document ID 5014280 l

Page 6 of 9 lil-STAR 100 RULEMAKING EDITORIAL COMMENTS Comment:

In the SURVEILLANCE REQUIREMENTS section, first sentence, delete "or the site-specific lift height requirements. developed under Design Features Section 4.4.6."

Reason:

Site-specific lift height requirements is not a option allowed by the Technical Specifications at this time. (However, please note that allowing i

site specific pad analysis and lift heights is being offered as a non-editorial l

comment from the HUG under a separate cover).

i Comment No.: '21 i

Section:

Technical Specification Bases - B 3.1.8, page B 3.1.8-1 and -2 Comment:

The line between the BACKGROUND and APPLICABLE SAFETY ANALYSIS sections should be a single line.

In the LCO and APPLICABILITY sections, remove reference to " flow rate limits" and

" circulation rate", respectively.

Reason:

The flow rate is not discussed in the 'LCO.

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Comment No.: 22 Section:

Safety Evaluation Report - Section 1.2 Comment:

In item F1.2, ieplace " Sections 1.2 - 1.4" with "Section 1.5". In item F1.3, i

replace "SAR"with " TSAR." In item FL4 replace 'Section 12" with "Section 1.3." In item F1.7, replace "SAR" with " TSAR."

Reason:

Correct typographical errors.

Comment No.: 23 Section:

Safety Evaluation Report - Sectior..).4.6 Comment:

Re-word the parentl.etical statement in the first sentence to read (changra shown in italics): "(a IIoltec trade namefor neutron shield material timilar to NS-4%)." In the last two sente ices, replace "NS-4-FR" with 'IIoltite-A."

Reason:

Correcttheneutronshieldmateriald:signationandrelatior ~ t.'NS-4-FR.

Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 7 of 9 lil STAR 100 RULEMAKING EDITORLAL COMMENTS 1

Comment No.: 24 Section:

Safety Evaluation Report - Section 4.5.2.4 Comment:

Replace "Section 4.5.5.2.1" with "Section 4.5.2.1" Reason:

Correct typographical error.

Comment No.: 25 l

l Section:

Safety Evaluation Report - Section 5.1.1 Comment:

In the second paragraph, delete "(NS-4-FR)"

Reason:

Reference to lloltite-A alone is sufficient.

Comment No.: 26 Section:

Safety Evaluation Report - Section 5.4.1.1 Comment:

Add "of the TSAR" after " Figure 5.1.1" Reason:

Add clarification.

Comment No.: 27 Section:

Safety Evaluation Report - Section 9.1.1 Comment:

In the first paragraph, last sentence, delete " top" In the third paragraph, replace '!istS" with " lists." In the text at the top of page 9-2, replace " staff's position that the closure weld for the outer cover plate..." with " staff'r position that the MPC lid-to-shell (LTS) weld..."

Reason:

The terms _" top lid", and " cover plate" are not correct terminology for the lil-STAR MPC design. Correct typographical error.

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r-Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 l' age 8 of 9 Ill-STAR 100 RULEMAKING EDITORIAL CO.o.,2FNTS j

i Comment No.: 28 Section:

Technical Specification Beses B Page B3.0-2, top section i

Comment:

At the top, replace "LCO 3.0.1 (wntinued)" with "LCO 3.0.2 (continued)"

l Reason:

Correct typographical error.

Comment No.: 29 Section:

Technical Specifications Bases B Page B 3.0-7, top section Comment:

At the top, replace "SR 3.0.2 (continued)" with "SR 3.0.3 (continued)"

Reason:

Correct typographical error.

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Comment No.: 30 Section:

Technical Specifications Bases B Pages B 3.0-8 and 3.0-9, top sections Comment:

At the top, replace "SR 3.0.2 (continued)" with "SR 3.0.4 (continued)"

Reason:

Correct typographical errors.

Commen; No.: 31 i

Section:

Technical Specification B LCO 3.1.8, Page 3.1.8-1 Comment:

In CONDITION A, add " gas" after " exit". In ACTION A.1, add "within j

limit" after " temperature." In the SR, add "MPC" after verify.

1 Reason:

For consisten v with ITS nandard wording and within the specification.

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Comment No.: 32 Section:

Technical Specifications, Section 4.0 B Page 4.0-1 1

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Mr. John C. lioyie r

l U. S. Nuclear Regulatory Commission l

Document ID 5014280 l

l Page 9 of 9 fil STAR 100 RULEMAKING EDITORIAL COMMENTS i

Comment:

In Specification 4.1.1 change "Not applicable" to " Varies".

Delete Specification 4.2.3.

Reason:

To provide the correct wording and delete an unnecessary specification.

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Comment No.: 33 1

1 Section:

Technical Specifications Bases B ACTIONS Section for LCOs 3.1.1,3.1.3, 3.1.5, 3.1.6, 3.1.7, 3.2.1, 3.2.2 Comment:

The bases for the Note modifying the ACTIONS in each of these specifications refers to "MPC" or "MPCs" in three places. Change this to "SFSC" or "SFSCs", as appropriate, in each bases location to match the note in the specification.

Reason:

Consistency with the specification.

Comment No.: 34 1

Section: -

Technical Specifications Bases 8 Pages B 3.8.1-3 Comment:

In the SURVEILLANCE REQUIREMENTS section, replace "SR 3.1.9.1" with "SR 3.1.8.1."

Reason:

Correct typographical error.

Comment No.: 35 Section:

Technical Specifications B LCO 3.2.1, Page 3.2.1-1 Comment:

Remove the semi-colon at the end of LCO 3.2.1.b Reason:

Correct typographical error.

Comment Noi36 j

Section:

Technical Specifications B Table 2.1-3, page 2.0-24 Commeat:

Add a space between "91" and " total."

j Reason:

Correct typographical error.

r Mr. John C lloyle U. S. Nuclear Regulatory Commission i

Document ID 5014280 Page 1 of 16 IlOLTEC COMMENTS ON III STAR 100 PROPOSED RULEMAKING 4

III-STAR 100 PROTOTYPE LESSONS LEARNED INTRODUCTION lioltec International, with the support of Commonwealth Edison, has been engaged in a full-scale lil-STAR 100 prototype manufacturing program at the UST&D facility in Pittsburgh, Pennsylvania. Under this program, one HI-STAR 100 overpack and one MPC-68 multi-purpose canister are being fabricated to tb, same exacting manufacturing, quality control, and quality assurance criteria which would apply to the ill-STAR 100 Systems destined for i

use.'

This prc> gram was initiated in June 1997 as part of our proactive efforts to climinate any 1

i quality dise(mnects between the design intent of the storage Topical Safety Analysis Report (TSAR) or transportation Safety Analysis Report (SAR) and the manufactured hardware. The program has yielded a wealth of practical information and manufacturing insights. UST& D is implementing the lessons learned in its manufacturing fixture upgrades and in shop procedure / traveler enhancements.

The knowledge acquired in this demonstration program has also helped us identify opportunities to improve the quality of the completed product and to eliminate ambiguities with respect to certain manufacturing and nondestructive examination (NDE) items that are addressed in a non-definitive manner in the TSAR and the associated Design Drawings. The i

object of this letter is to describe the enhancements UST&D, Holtec, and the Holtec Users Group (HUG) believe should be incorporated into Revision 10 of the HI-STAR 100 TSAR through modifications to the Design Drawings and, where necessary, in the text of the documents. Upon receipt of concurrence from the SFPO, Holtec will proceed to include these enhancements in the appropriate documents.

Each of the lessons learned which resulted in a change to the license application, no matter how insignificant,is detailed in this list. All proposed enhancements detailed in this list have one common attribute: they have no material effect on the analyses performed in support of the TSAR (i.e., structural, thermal, shielding, criticality, and confinement / containment). In j

cther words, no existing calculations need to be changed and no new calculations are required.

All items are listed in Section i below in the question / answer format and the resolution to the questions are clear!y set down.

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o Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 2 of 16 IlOLTEC COMMENTS ON III-STAR 100 PROPOSED RULEMAKING Ill STAR 100 PROTOTYPE LESSONS LEARNED SECTION I Q.1:

Can af agnetic Particle Examination (MT) as prescribed in Section V of the ASME Code be substituted for the Liquid Penetrant (PT) Examination in the HI-STAR 100 I

i overpack weld examination?

Response

PT and MT methods of NDE are considered equivalent by the ASME Code.

3 Therefore, from a technical standpoint MT can be used in liet: of ?T, or vice versa.

i Resolution:

Dwe.1397. Sht.1 Add the following to Note 8:

"F. Magnetic Particle (MT) per ASME Section V. Article 7 with acceptance criteria per ASME Section III, Subsection NF, Article NF-5340."

4 Add "or MT per Note 8.F" to the call outs for the intermediate

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shell welds.

I Dwe.1399. Sht.1 Add the following to Note 10:

"F. Magnetic Particle (MT) per ASME Section V, Article 7 with acceptance criteria per ASME Section III, Subsection NF, Article NF-5340."

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Add "or MT per Note 10.F" to th; call outs for the intermediate shell welds.

Dwe.1399. Sht. 3 Add "or MT per Note 10.F on Sht.1" to the call outs for the intermediate shell welds.

Q,2:

What is the localized thinning tolerance in the containment shell of the lil-STAR Ift0 overpack?

Response

First, the term " localized" must be defined. A local region in a shell of j

thickness t and radius r should have a characteristic dimension that is less i'

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Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 3 of 16 IlOLTEC COMMENTS ON HI-STAR 100 PROPOSED RULEMAKING l

Ill-STAR 100 PROTOTYPE LESSONS LEARNED l

than 1.0 * (rt)"* (per NB-3213.10) For the HI-STAR 100 cverpack, r =

34.375", t = 2.5". Therefore, a local region in the Hi-STAR 100 overpack is defined by a patch which does not exceed 9.27 inches in either the longitudinal or circumferential direction.

In a localized region defined above, the r. Jitional stress due to reduced wall thickness is labeled as the local membrane stress (PJ which has a 50%

greater allowable stress intensity limit than the primary membrane stress. For conservatism, we should restrict permissible localized wall thickness reduction to 10% of the nominal shell wall thickness over an area which does not exceed 9.0 inches in either the longitudinal or circumferential directions.

I Resolution:

Note 10 on Dwg.1397 Sheet 1, Note 7 on Dwg.1398 Sheet 1, and Note 11 on Dwg.1399 Sheet I will be revised to read as follows.

"Imcal grinding on the containment boundary shall not result in a loss of

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metal thickness in excess of 10% of the nominal base metal thickness over an area which exceeds 9 inches in either the longitudinal or circumferential direction. Final metal thickness in areas of local grinding shall be confirmed by UT examination as appropriate."

l Q.3:

Clarify the radiography and post-weld heat treatment requirements for the I

containment boundary of the HI-STAP 100 overpack.

j

Response

' All circumferential and longitudinal bt:t welds in the HI-STAR 100 overpack containment boundary shall be examined by radiography (RT) and by surface examinations, MT or PT and VT as required by the ASME Code Section 111, j

Subsection NB, NB-5210, NB-5220, and NB-5230.

i Welds which fail to pass the examinations noted above, shall be excavated l

and repaired, as required until the subject weld passes the above-mentioned l

examinatioas. Subsequent to successful NDE, the entire containment boundary shall be subject to post weld 1 eat treatment (PWHT) per Table NB-l 4622.1-1. The heat-treated vessel shall be de-scaled, if required, before the intermediate shells are attached to its outs.ide surface. Confirmatory NDE after the PWHT is not necessary because the PWHT is not known to introduce new weld defects in nickel steels.

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Mr. John C.11oyle U. S. Nuclear Regulatory Commission Document ID 5014280

' Page 4 of 16 i

HOLTEC COMMENTS ON III-STAR 100 PROPOSED RULEMAKING III STAR 100 PROTOTYPE LESSONS LEARNED l

PWIIT after the intermediate shells are welded to the top flange and bottom plate is not necessary. The intermediate shells are non-pressure retaining parts being welded to pressure retaining material. The pressure retaining material to which the intermediate shells r, welded is the overpack top flange and bottom plate. Both of which ar, heavy-walled sections in excess of 7 inches thick. Intermediate shells items 12,13, and 14 are welded to the top flange and bottom plate by % inch groove welds. Intermediate shell items 15 and 16 are welded to the top flange and bottom plate by a 1-1/4 inch groove weld and a 1-inch groove weld, respectively. ASME Section Ill,'

Table NB-4622.7(b)-1 recognizes the need to exempt small welds from the PWIIT requirements.

Performing a localized PWIIT of the intermediate shell welds to top flange i

and battom plate will cause the material away from the weld area to experience elevated temperatures which will have an adverse effect on the 4

properties of the material. Therefore, while Table NB-4622.7(b)-1 does not explicitly exempt the intermediate shell-to-top flange and bottom plate welds,

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local PWHT of these welds should not be performed to protect the integrity of the suirounding material.

1 Resolution:

Table 2.2.15 of the Ill-STAR 100 TSAR will be revised to include exemptions to NB-5120(a) which specifies RT to be performed after PWIIT

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and NB-4622.6 which specifies the PWHT requirements for the intermediate j

shell to top flange and bottom plate.

Q.,4:

Please,elatify the correct sequence to perform the hydrostatic testing and helium leak 5ge testing during the fabrication of the Ill-STAR 100 overpack.

Response

Ilydrostatic tesdng of the HI-STAR 100 overpack containment boundary is required by 10CFR71.85(b) and ASME Code Section Ill, Subsection NB,

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NB-6221.10CFR71.85(b) specifies that before first use, the containment 3

system of each packaging must be tested at an internal pesure at least 50 percent higher than the MNOP. NB-6221 specifies that the installed system shall be hydrostatically tested at not less than 1.25 times the lowest design pressure.

Hydrostatic testing of the HI-STAR 100 overpack exposes its internal steel surface to water. Performing the hydrostatic test prior to the painting of the i

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Mr. John C. Ilovle U. S. Nuclear Regulatory Commission Document ID 5014?.80 Page 5 of 16 IlOLTEC COMMENTS ON III-STAR 100 l'ROPOSED RULEMAKING III-STAR 100 PROTOTYPE LESSONS LEARNED overpack internal surfaces will unnecessarily subject the overpack to corrosion. The hydrostatic test should be performed after the HI-STAR 100 overpack is completed to minimize the potential for corrosion of the overpack and to verify that the completed system meets the requirements of 10CFR71.85(b) and NB-6221.

Ifelium leakage testing of the Ill-STAR 100 overpack in accordance with ANSI N14.5 is recommended by NUREG-1617, Subsection 8.2.3. ANSI N14.5, Parag 9h 7.3.3 states that to the extent practical, all joints and seams on the containment system should be tested in the fully assembled state.

Therefore, the helium leakage testing of the III-STAR 100 overpack should be performed after the overpack is completed.

If the helium leakage testing were performed prior to the installation of the overpack intermediate shells, the seating surface for the metallic seal on the top flange must be machined at that time (before all welding has been completed). After successfully completing the helium leakage testing, the intermediate shells would be welded to the top flange. The welding of the interraediate shells introduces a great deal of heat into this region and could possibly cause minor distortion of the flange, thereby altering the seal seating surface on the top flange. Performing the helium leakage testing after the completion of the fabrication of the III-STAR 100 overpack allows the seal seating surface to be machined after the attachment of the intermediate shells and thereby maximizes the quality of the gasketed joint.

Therefore, it is much preferable to perform the hydrostatic and helium leak tests after completion of all welding operations on the III-STORM.JO overpack.

Resolution:

The III-STAR 100 TSAR will be revised to specify that the hydrostatic and helium leakage testing shall be performed after the completion of the fabrication of the ill-STAR 100 overpack.

Q.5:

Clarify the required tolerance for the helium backfill.

Response

Step 29 of Subsection 8.1.5 of the III-STAR 100 TSAR specifies the helium mass with a tolerance of +0/-10% This strict tolerance was specified to ensure the proper helium mass was present to support the thermosiphon effect

Mr. John C. licyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 6 of 16 HOLTEC COMMENTS ON III STAR 100 PROPOSED RULFJWAKING III-STAR 100 PROTOTYPE LESSONS LEARNED within the MPC. As no credit is taken for the heat transfer provided by the thermosiphon mechanism, a strict tolerance on the helium backfill is not required.

Resolution:

The Hi-STAR 100 TSAR will be revised to specify the helium backfill tolerance as +0/-25% Please note that this value is also quoted in Table 3-1 of the H1-STAR 100 storage technical specifications, and needs to be revised 4

by the NRC accordingly.

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Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 50t4280 Page 7 of 16 HOLTEC COMMENTS ON HI STAR 100 PROPOSED RULEMAKING HI-STAR 100 PROTOTYPE LESSONS LEARNED In addition to the previous issues, the following minor changes to the Design Drawings are l

identified in Section 11 below with the affected document (s), description of change, justification and consequence to supporting design analyses provided SECTION II i) Affected Documents:

Dwg.1401; Sht.1 & Sht. 2 Description of Change:

Change the box ID from 6.053" (+/.06") to 6.053" (+/.06")

STS',

j Justification:

The box ID is controlled during the fabrication by the pitch, which has the tolerance opecified on the drawings. The pitch is specifically controlled by the fixturing. The fixturing ensures that the pitch will meet the drawing requirements and this will ensure the cell sizes are met. The box internal diameter, on the other hand, is a derived, surface-to-surface dimension which cannot be directly measured. Therefore, the box ID dimension is more appropriately shown as an average dimension over the length of the fuel basket.

Consequence to Supporting Design Analyses: None

- 11) Affected Documents:

Dwg.1401; Sht. 3 j

Description of Change:

Change the %" diameter handling hole location from 1" Ref to 2" Ref.

Justification:

In its current location, the hole does not allow sufficient clearance to the edge of the top of the cell wall.

Conseqr.ce to Supporting Design Analyses: None

- lii) Affected Documents:

Dwg.? 1395, Sht 1; Dwg.1396, Sht 2; Dwg.1401; Sht 1; Dwg.1402; Sht. 2 i

I 1

I 8. Surface-to-Surface j

i i

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Mr. John C. Iloyle U. S Nuclear Regulatory Commission Document ID 5014280

' Attachment 2 Page 8 of 16 IIOLTEC COMMENTS ON lil STAR 100 PROPOSED RULEMAKING lil-STAR 100 PROTOTYPE LESSONS LEARNED Description of Change:

Note 11 on Dwgs.1395 and 1401 Sht.1, and Note 12 for Dwgs.1396 and 1402 to be modified as follows:

" Grinding of NB compor.ents ( i.e., the MPC enclosure vessel) shall not result in greater than.05" loss in nominal base metal thickness over an area which exceeds 4 inches in the longitudinal or circumferential direction. Final thicke. esses in local areas of grinding shall be confirmed by UT examination, as appropriate."

Justification: The original note only addressed grinding around weld areas and did not address grinding away from welds. no, the word nominal was added to ensure that the note would not be interpreted that base metal loss was evaluated against the "as supplied" material thickness, but rather the thickness specified in the Bill-of-Material.

As discussed in item Q3 above for the overpack, a local region in a shell of thickness t and radius r should havea characteristicdimensionthatisless than1.0 * (rt)n2 (per NB-3213.10). For the HI-STAR 100 MPC, r = 33.6875",

t = 0.5". Therefore, a local region in the HI-STAR 100 MPC is defined by a patch which does not exceed 4.1 inches in either the longitudinal or circumferential direction.

In a localized region defined above, the additional stress due to reduced wall thickness is labeled as the local membrane stress (PJ which has a 50%

greater allowable stress intensity limit than the primary membrane stress. For conservatism, we should restrict permissible localized wall thickness reduction to 10% of the nominal shell wall thickness over an area which does not exceed 4.0 inches in either the longitudinal or circumferential directions.

Consequence 1: ~pporting Design Analyses: None iv) Affected Documents:

Dwg.1401; Sht 4; BM-1479 l

Description of Change:

Change the affected basket support location dimensions on this drawing as necessary to allow for 3/16" nominal gap.

Also, delete item 9B.

l

m -

Mr. John C. Hoyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 9 of 16 HOLTEC COMMENTS ON /P-STAR 100 PROPOSED RULEMAKING HI-STAR 100 PROiOTYPE LESSONS LEARNED Justification:. The old dimensions were based on the location of the midpoint of horizontal and vertical plates. During fit-up, first contact of the plates will be on the very end. These dimensions are surface-tu-surface dimensions, as opposed to directly measurable, point to point dimensions. It is more appropriate for these dimensions to be shown as average over the entire length of the MPC.

For item 9B, the uominal ID of thc canister is 67.375. The largest it could be is 67.625". The nominal basket size at the location is 67.07".

Consequence to Supporting Design Analyses: Ncne v) Affected Documents: Dwg.1395, Sht 4; BM-1478 Description of Change:

Clarify the drawing to indicate the gap at the basket support location to be 3/16" (nom.). State all dimensions as "STS" dimensions.

Justification: The 3/16 (nom.) gap is consistent with the MPC structure design basis. The basket-to-basket support gaps are surface-to-surface dimensions, as opposed to directly measurable, point to point dimensions. It is more appropriate for these dimensions to be shown as average over the entire length of the MPC.

Consequence to Supporting Design Analyses: None vi) Affected Documents: Dwg.1395, Sht 4; Dwg 1401, Sht 4 Description of Change:

On Note 5 on Dwg.1395 Sht. 4 and Note 4 on Dwg.1401 Sht. 4, change the "68-9/16" ( +/-1/8")" to "68,9/16" ( +/-

1/8") STS." Also, eliminate "from the top of the baseplate to the top of the basket supports" and replace with "over the entire length of the basket supports".

Justification:

This dimension is a surf :e-to-surface dimension, as opposed to a r

directly measurable, por to point dimension. It is more appropriate for this iimension to be shown as average over the entire length of the MPC. The second change is required since the current statement conflicts with Dwg.1396 Sht. I and Dwg.1402 Sht.1 which call for the shim to start 2" and 1.5", respectively, from the baseplate.

Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 10 of 16 IlOLTEC COMMENTS ON lil STAR 100 PROPOSED RULEMAKING lil-STAR 100 PROTOTYPE LESSONS LEARNED l

Consequence to Supporting' Design Analyses: None

~

vii) Affected Documents: Dwg.1396, Sht 2; Dwg.1402, Sht. 2 Description of Change:

Allow the option to make closure ring from one piece and eliminate the radial welds which attach the two halves.

l Justification:

This change offers the users the option of eliminating unnecessary welds when the weld machine and fuel building size can handle a single piece installation of the closure ring.

Consequence to Supporting Design Analyses: None viii) Affected Documents: Dwg.1396, Sht 2; Dwg.1402, Sht. 2 Description of Change:

Change 5/15" chamfer on the closure ring inner diameter to 1

a 5/16" chamfer i-Justification:

Typographical error.

Cousequence to Supporting Design Analyses: None

'ix) Affected Documents: Dwg.1396, Sht. 4; Dwg.1402, Sht. 4 Description of Change:

Make the following changes to the drain & vent systems.

a) Change 3/16" radii on cap to 1/8" Ref.

b) For vent / drain tube & cap, add note as follows:

" Thread reliefs, chan fers & radius not shown on drawing may be added as necessary to meet good engineering and fabrication practices."

c) Delete the decimal tolerance of +/.003" and the fractional

' tolerance of 0.015"for the tube and cap.

d) For Dwg.1402 Sht. 4 only, the detail of item 40, change u

fi Mr. John C. Iloyle i

U. S. Nuclear Regulatory Commission Document ID 5014280 Page 1t of 16 IlOLTEC COMMENTS ON III STAR 100 PROPOSED RULEMAKING III-STAR 100 PROTOTYPE LESSONS LEARNED 4" dimension to 3.75" Ref.

Justification: These tolerance changes are necessary to ensure consis:ency with the design intent.

Consequence to Supporting Design Analyses: None x) Affected Documents: Dwg.1396, Sht. 6; Dwg.1402, Sht. 6 Description of Change:

Eliminate PT requirements for fuel spacers.

Justification: pts are not required. Specifying a pts for these welds are drafting errors.

I Consequence to Supporting Design Analyses: None xi) Affected Documents: Dwg.1397, Sht. 4 Description of Change:

Change the location of the 1/16" diameter hole in the seal from %" +/- 1/32 to 5/32" Ref.

Justification: This corrects a drawing error.The area where the hole is to be drilled is 0.32" wide.

i Ccmsequence to Supporting Design Analyses: None xii) Affected Documents:

Dwg 1397; Sht.1,Dwg 1398; Sht.1 : Dwg 1399; Sht.1

' Description of Change:

Replace Note 4 and with the note and tolerance block from drawing 1401, Sht.1 (Note 4)

Justification: The appropriate tolerances to meet the design intent are delineated in Note 4 on Drawing 1401, Sheet 1.

Consequence to Supporting Design Analyses: None

' xiii) Affected Documents:

Dwg 1397; Sht.1, Dwg 1399; Sht.1 i

Description of Change:

Change the 68-3/4" (+/-1/32") dimension to 68-3/4"(+/-

1/32") STS.

i

Mr. John C. licyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 12 of 16 llOLTEC COMMENTS ON III-STAR 100 PROPOSED RULEMAKING lil-STAR 100 PROTOTYPE LESSONS LEARNED Justification: This dimension is a surface-to-surface dimension, as opposed to a directly measurable, point to point dimension. It is more appropriate for this dimension to be shown as average over the entire length of the overpack.

Consequence to Supporting Design Analyses: None xiv) Affected Documents:

ITwg.1397, Sht. 5 Description of Change:

Add " tool radius as required" to trunnion at location where diameter changes. Change the 5-7/8" dimension on the locking plate to a reference dimension.

Justification: Radius needed to manufacture in accordance with the design intent. Hole in locking plate is not critical as long as it can be installed over the trunnion.

Consequence tc, Supporting Design Analyses: None xy) Affected Documents:

13M-1476 Description of Change:

For item 33, in the material column, add "(holder only)" after

" brass" Justification: This changes provides necessary cladfication for material procurement. Only the holder is made of brass. The rupture disc is made of nickel, teflon and 316 S/S.

Consequence to Supporting Design Analyses: None xvi) Affected Documents:

Dwg.1399; Sht.1 Description of Change:

Change 8-1/2" min. dimension (thickness of inner shell plus intermediate she!!s) to 8-1/2" min. (STS.)

Justification: This dimension is a surface-to-surface dimension, as opposed to a directly measurable, point to point dimension. It is more appropriate for this dimension to be shown as surface average over the entire length of the

+

overpack.

Consequence to Supporting Design Analyses: None

Mr. John C. Iloyle U. S. Nuclear Regulatory Commission Document ID 5014280 Page 13 of16 110LTEC COMMENTS ON HI STAR 100 PROPOSED RULEMAKING Hi STAR 100 PROTOTYPE LESSONS LEARNED xvii) Affected Documents:

Dwg.1395 Shts. 2,3 &4; Dwg.1401 Shts. 2,3 & 4 Description of Change:

Add a note that allows the fabricator to add additional welds to any of the stitch welds defined on the drawings, while still prohibiting full seal welding of the Boral sheathing.

-1 Justification: For sheathing, additional welds will provide better attachment of the Boral and sheathing. For the supports and shims, these items may be made from i

more than one piece. Each end of the basket support should be welded.

Consequence to Supporting Design Analyses: None xviii) Affected Documents: Dwg.1396, Sht. 6; Dwg.1402, Sht. 6 Description of Change:

Add a note that states if upper fuel spacers are not required then the fuel spacer holes on the bottom of the MPC lid do j

not need to be made.

Justification: For tl ose applications where fuel spacers are not required, it is inappropriate to manufacture fuel spacer attachment holes into the MPC lid. In addition, a solid surface provides better radiation shielding than a threaded hole with a plug.

)

Consequence to Supporting Design Analyses: None 1

xix) Affected Documents: Dwg.1396, Sht. 2; Dwg.1402, Sht. 2 Description of Change:

Add a 15* REF. chamfer to the outer vertical circumference of the MPC closure ring. See Figure 1.

]

Justification: Adding the 15' chamfer will better position the weld nozzM and thereby lead to a better quality weld.

Consequence to Supporting Design Analyses: None xx) Affected Documents: Dwg.1395, Sht. 4; Dwg.1401, Sht. 4 Description of Change:

Revise Note 2 of Dwg.1395, Sheet 4 and Dwg.1401, Sheet j

' 4 to change "The total length of" to "The total length and n

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O Mr. John C. Iloyle U. S. Nud:ar Regulatory Commission Document ID 5014280 Page 14 of 16 IlOLTEC COMMENTS ON lil-STAR 100 PROPOSED RULEMAKING III-STAR 100 PROTOTYPE LESSONS LEARNED width of". Also, add " Welds between shims to make the required final thickness shall be the same as the welds required to attach a single shim to the MPC."

Justification: Revision of this note allows the fabricator to use multiple shims to improve the precision of final dimensional compliance.

Consequence to Supporting Design Analyses: None xxi) Affected Documents: Dwg.1395, Sht. 4; Dwg.1401, Sht. 4 Description of Change:

Change the detail shown as items 5G and 9A,9B, and 9C on Drawing 1395, Sheet 4 and items 5 and 8 on Drawing 1401, Sheet 4 to that shown in Figure 2.

Justification: Revision of this detail is an enhancement to the design which improves the ability of the basket shims to accommodate fabrication tolerances.

Consequence to Supporting Design Analyses: None xxii) Affected Documents: Dwg.1396, Sht. 4; Dwg.1402, Sht. 4; BOM 1478; BOM 1479 Description of Change:

On the drawings, add a 1/8 inch seal weld at the socket connection between the drain pipe and the coupling, item 26.

On the Bills-of-Materials, change the description of Item 26 to " coupling."

Justification: The seal weld is required to meet the design intent for this socket connection.

The absence of th seal weld was a drafting oversight. The coupling description is a correction.

Consequence to Supporting Design Analyses: None I

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