ML20153G973
| ML20153G973 | |
| Person / Time | |
|---|---|
| Site: | 07105010 |
| Issue date: | 02/03/1986 |
| From: | Kingsley K GENERAL NUCLEAR SYSTEMS, INC. |
| To: | Roberts J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20153G975 | List: |
| References | |
| REF-PROJ-M-37 26419-1, C8602-1, NUDOCS 8602280559 | |
| Download: ML20153G973 (7) | |
Text
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RETURN TO 396-SS N
GENERALNUCLEAR SYSTEMS,INC.
ACHEM-NUCLEAR COMF%NY 135 Darhng Dnve
- Awon.Connecteut 06001
- 203/677-0457 February 3, 1986 C8602-1 e
!!r. John P. Roberts, Project fianager 4
Advanced Fuel and Spent Fuel Licensing Branch gbE[g s
Division of Fuel Cycle and l'aterial Safety g.
-e U.S. Nuclear Regulatory Commission g
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Washington, D.C.
20555 x E4 3
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SUBJECT:
Fuel Basket Evaluation a
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Project fi-37 N
p REFERENCES':
(A) NRC letter-dated October 14, 1985 Ti L. C. Rouse to _V._ J. Barnhart (GNSI).
(B) GNSI letter C8511-14 dated November 27, 1985 K. R. Kingsley-to J. "P. Roberts (NRC).
(C) NRC letter dated December 20, 1985 J. P. Roberts to V. J. Barnhart (GNSI).
Dear Mr. Roberts:
This is to transmit to you the GNSI evaluation of the fuel basket used for the unlicensed cask demonstration progran at INEL. Also, as requested by reference (A), we have assessed the impact of the observations at INEL on the licensed use of the CASTOR V/21 cask at an Independent Spent Fuel Storage Installation. This assessment has been prepared in the form of a new section to be incorporated into the upcoming revision of the CASTOR V/21 TSAR.
This revised section is included with.this -transmittal for your review.
The information contained in-the enclosed' documents addresses the itens discussed during the December 13,1985 meeting concerning the contents of our preliminary report (Reference B).
Attachment one _provides a sumary of our response to these i,tems as outline by-you in Reference C.
Please note that one of the items requested additional basket. drawings.- - Proprietary drawings and the required affidavit-are -theref6re also enclosed in response to your request.
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$ a$ Please feel free to contact us if there are any questions on the enclosed e
naterials.
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GENERAL NUCLEAR SYSTEMS, INC.
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ATTACH"ENT ONE T0.C8602 i GHSI-RESPONSE TO COMMCFTS IN, MRC LETTER, PROJECT M-37, DATED DECEMBER 20, 1985-i ITEM 1 l
COMMENT:
Mith respect to resolving causes of the weld area failures,.
these should be related to strain mechanisms. Thus potential mechanisms for these failures'should be explained 'and assessed
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with respect to INEL demonstration conditions and the CASTOR
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V/21 cask used. This assessment should be made with reference
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to the thermal analysis provided in the TSAR. Furthermore, the thermal stress analysis should be revised to include the effect j
of gusset plates and correct material properties and also should be revised to include reporting the stresses at all points of j
'the structure, f
RESPONSE
Section 6.4 of our evaluation report for the test cask at INEL describes the potential mechanisms for. the observed indications, based on the specific cask and test conditions at INEL.
A thermal stress analysis has also been performed for the CASTOR V/21 cask and ISFSI conditions defined by the TSAR. This-i
-analysis uses appropriate material properties committed to in' i
the TSAR and includes the effect of gusset plates. A description of the analysis will he incorporated into the TSAR including resulting thermal stresses calculated for points throughout the basket structure.
ITEM 2 i
COMMENT:
Measures with respect to basket fabrication and/or design, which.
will he taken to assure that such weld failures could not occur both under normal and accident-design conditions, should be provided.- Tolerances should be shown that control' the maximum and minimum gap dimensions.
RESPONSE
The CASTOR V/21 fuel basket design is described in the TSAR.
The thermal stress analysis demonstrates the acceptability of 4
this design for the limiting conditions defined by the TSAR.
Dimensions and tolerances required to support these conclusions are provided on proprietary manufacturing drawings. These-2 drawings are being submitted for_ yo4r review'(see item 3 response).
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l ITEM 3 COMMENT:
Additional detailed basket drawings at different axial positions to include and exclude gusset plates should be provided with the basket welding plan.
Non-structural welds which are not related to basket structural integrity, i.e., which are without a safety function, should be identified and distinguished from welds which are relied upon to maintain basket structural integrity.
RESPONSE
The proprietary drawings submitted with this -letter are provided in addition to the various figures already available in the TSAR. This information is adequate to fully describe the basket structure. The response to Item 4 addres es the classification of welds with regard to safety.
It should be emphasized that with respect to fabrication, all welds are controlled by appropriate documentation and quality assurance neasures.
ITEM 4 COMMENT:
A detailed structural analysis of the cask basket under both normal and accident design conditions alluded to in Section 4.0 of your preliminary report should be provided to demonstrate the structural integrity of the basket.
It is assumed by us that this analysis will not take any credit for non-structural welds, i.e., joint welds, including, but not limited to, those welds which show evidence of failure in the INEL demonstration.
If such should not he assumed in this analysis, this should be made clear.
If neasures referred to in item 2 above are taken, it should also be made clear whether this analysis assumes these are implemented.
If such measures are taken, they will be reflected in the supplied drawings referred to in item 3 and in cask fabrication procedures and documentation.
RESPONSE
As described in item 2, a thermal stress analysis was performed for the CASTOR V/21 and conditions defined by the TSAR. This analysis shows that themal stresses in the basket are acceptably low. Therefore, for nomal conditions (3 g naximum handling load) it is reasonable to take credit for the presence of these welds to maintain exact geometry and positioning of all fuel cavities and fuel assemblies.
Under this set of conditions, the structural analysis presently contained in the TSAR (Section 4.2.1.4) renains valid.
i Since the conditions contributing to maximum thermal stresses are the same for accident and nornal structural leadings, credit f
for all basket welds may also be takaa in evaluating accident l
conditions. The basket safety function is to maintain criticality safety and this criterion is met by the presence of borated steel plates between assemblies and by the presence of neutron flux traps. Therefore, even though all welds are available to mitigate the consequence of accident conditions, only the weld identified as SN-6 (GHS drawing A500.ll-15) is defined as a safety weld. This weld secures the spacers which maintain the flux trap distances.
Section 8.2.1.3.3 of the TSAR will be revised to discuss the safety function of these spacers.
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.I ITEtt 5 C0ffiENT:
Material properties which reflect actual testing done on these materials should be included and their use carefully explained in terms of analyses supplied to us and design commitments for naterials with respect to the Topical Report for the CASTOP V/21 cask, for axample, values for Radionox (boronated stainless steel).
Particular attention should be directed toward demonstration that either brittle fracture is not a failure mode or if it is, then safety margins against brittle fracture are adequate under dynamic loading conditions.
RESPONSE
Section 5 of our IHEL Evaluation Report contains material property data for Radionox as well as an explanation of how this infomation is applied to the analysis of the test cask and conditions r 1NEL.
The way in which material property information is applied to the analysis of the CASTOR V/21 fuel basket and conditions defined by the TSAR is included in the new TSAR section (4.2.1.4.2) which will be incorporated into the upcoming revision.
ITEf1 6 C0!?!ENT:
Data on weld tests performed should be supplied distinguishing between welds which have a safety function, that is, which are relied upon to maintain the structural integrity of the basket and non-structural welds.
RESPONSE
flaterial testing results (including welds) are provided in Section 5 of our INEL Evaluation Report. The response to item 4 addresses the classification of welds with regard to safety.
ITEM 7 C0fffENT:
As discussed in our meeting, based on INEL measurements and your analysis, explain why there is no effect observed due to sub-critical multiplication with respect to dose calculations
(
Reference:
Correction 7.3.2 in our letter of approval for the CASTOR V/21 Topical Report).
In relation to this explanation, provide drawings with changes related to cask borehole length shortening and the addition of steel plugs at the bottom of boreholes to provide additional reduction of gamma dose rates at positions near the cask wall top and botton. Also provide an explanation of this improvement to cask shielding design.
These changes are to be reflected in cask fabrication procedures and documenta tion.
RESPONSE
Previously addressed by separate correspondence.
0926V
4 AFFIDAVIT SUBMITTED TO NUCLEAR REGULATORY COP 9tISSION BY GENERAL NUCLEAR SYSTEMS, INC.
CONCERNING CONFIDENTIAL INFORMATION AND TRADE SECRETS.
I, Robert T. Anderson, depose and say-that I as the Director, Cask Systems of
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General Nuclear Systems, Inc. (GNSI) duly authorized to make this affidavit, and have reviewed or caused to have reviewed the infomation which is l
identified as proprietary and referenced in the paragraph immediately below.
I am submitting this affidavit in confomanc? with the provisions of 10 CFR -
2.790 of the Commission's regulations for withholding this information from public disclosure.
The infomation for which proprietary treatment is sought is as follows:
1.
B525.106-544 Rev a: Basket Castor V/21, Welding Plan 2.
A500.11-15, rey d: Basket Castor V/?1 VEPCO 3.
A500.11-15/2, rev 5: Basket Parts List These documents have been appropriately designated as proprietary.
I have personal knowledge of the criteria and procedures utilized by GNSI in designating information as a trade secret or as privileged / confidential infomation of a commercial or financial nature.
pursuant to the provisions of paragraph (b) (4) of Section 2.790 of the -
Commission's regulation, the following is furnished for consideration by the 4
Commission in determining whether the infomation sought to be withheld from
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public disclosure, included in the above referenced documents, should be withheld.
1.
The information sought to be withheld from public' disclosure consists of-design drawings and fabrication details which is owned and held in confidence by GNSI, and not disclosed to any third party without first obtainin; that party's written cgreement to sid the information in confidence.
1 2.
The ownership of this infomation results in a substantial economic advantage to GNSI, over its competitors who do not know or use it.
1 3.
The infomation is of a type customarily held in confidence by GNSI and not customarily disclosed to the public. GNSI has a rational basis for detemining the type of information to be held in confidence.
4.
The infomation is being transmitted to the Commission under the provisions of 10 CFR 2.790 with the understanding that it is to be received and held in confidence by the Commission.
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5.
The information, to the best of my knowledge and belief, is not available to public sources, and any disclosure to third parties has been iaade pursuant to regulatory pi ovisions o.
proprietary agreements which provide for continuing the confidentiality of the information and only to those parties Who need to know the information.
6.
Public disclosure of the information is likely to cause substantial harm to the competi tive posi tion of GNSI because devel opment of this information by GNSI ree" fred thousands of man hours of effort and hundreds of thousands of dollars.
To the best of my knowledge and belief, other parties, including competitors, would have to undergo similar expense in generating equival ent in formation.
Public disclosure of the information would enable a competitor to avoid the effort and expense to develop this information and would enable that competitor to develop a similar product at a significant cost savings, thereby impairing the competitive position of GNSI.
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/A(Jgpx L.S.
Robert T. Anderson
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Director, Cask Systems General Nuclear Systems, Inc.
STATE OF SOUTH CAROLINA )
- ss.
PROBATE COUNTY OF RICHLAND
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On this J31 day of January,1986, before me, a Notary Public in and for the State of South Carolina, duly comissioned and sworn, personally appeared ROBERT T. ANDERSON, to me known to be the Director, Cask Systems for General Nuclear Systems, Inc. and on oath stated that he was authorized to make this Affidavit on behalf of the Corporation.
IN WITNESS WHEREOF, I have set my hand and affixed my official seal as of the day and year first above written.
AAA 2//) w Sharra L.)Rollins6n ' /
[ NOTARY SEAL]
Notary-Ptiblic, State'of South Carolina My Comisstor. Expires:
3/11/90