ML20207A342
| ML20207A342 | |
| Person / Time | |
|---|---|
| Site: | 07109268 |
| Issue date: | 05/21/1999 |
| From: | Fuller E External (Affiliation Not Assigned) |
| To: | NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| BFS-NRC-99-045, BFS-NRC-99-45, NUDOCS 9905260274 | |
| Download: ML20207A342 (8) | |
Text
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BNFL Fuel Soluti:nc rzrporati:n
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1 Victor Square
'". FuelSolutions 5'"[3}@lll66 Fax: (831) 438-5206 i
May 21,1999 BFS/NRC 99-045 Docket No. 71-9268 File No. SNC-109 Director, Office of Nuclear Material Safety and Safeguards US Nuclear Regulatory Commission Washington, D.C. 20555-0001
Subject:
Schedule for Certain TranStor Part 71 Submittals
Dear Sir,
On May 18,1999, representatives of BNFL Fuel Solutions (BFS) met with the NRC to discuss the following five issues regarding the TranStor Part 71 application: 1) the results of the NRC Acceptance Review; 2) integration of the Trojan differences; 3) the results of the Impact Limiter Drop Tests; 4) high burnup fuel; and 5) proposed alternative Part 71 drawings. As a result of this meeting, BFS committed to document its schedule to complete the submittals that support the NRC's review. The schedules for these submittals are as follows:
Results of the NRC Acceptance Review is our interpretation of the questions asked by the NRC at the May 18,1999, meeting. Please let me know if we have misunderstood these. BFS will provide a response to each of these questions, including any necessary supporting information, such as revised drawings, calculations, and Safety Analysis Report (SAR) changed pages, by the end of June 1999.
Intecration of the Troian Differences During the meetir.g, BFS noted that changes have been made to the baskets used at Portland General Electric's Trojan nuclear plant. BFS will provide the NRC with a revision to its
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TranStor Part 71 application to address these changes by the end of June 1999. Attachment 2 provides a description of the Trojan changes and a summary of the potential impact to the application, including calculations and SAR drawings.
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Results of the Impact Limiter Dron Tests
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The meeting included a presentation of the results of the Part 71 impact limiter tests conducted to date. BFS has concluded that additional dynamic tests of the impact limiter are desirable and prefers to provide one submittal containing the complete test results. In order to fabricate additional scale models, schedule the drop tests, and prepare the necessary changes to its TranStor Part 71 application, BFS has revised the submittal date from June 1999 to the end of 9905260274 990521 3
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_U.S. Nuclear Regulatory _ Commission BFS/NRC 99-045 :
y Page 2 -
ugust 1999.
High Burnuo Fuel The TranStor Part 71 application included fuel contents with a burnup exceeding 45
- GWD/MTU. BFS has decided not to pursue furtherjustification of such fuel contents at this time. If BFS pursues such justification at a later date, a mutually satisfactory schedule will be developed with the NRC.
' Altemative Part 71 Drawinns -
~ At the meeting, BFS proposed an attemative approach to SAR drawings in order to reduce their detail yet provide a description of the critical safety features of the TranStor System. BFS will work with the NRC to develop a satisfactory altemative but does not wish to impact the current review. Therefore, BFS requests that the NRC continues the review of the drawings currently contained in the Part 71 application. A schedule for alternati5e drawings will be developed at a later date.
The commitments made in this letter are documented in Attachment 3.
1 If any questions exist relative to this submittal, please contact Wayne A. Massie at (831) 438-6444.-
Sincerely, i
f E.D.Ful President & CEO Enclosure -
cc)
Mr. L. G. Dusek Ms. Marilyn Meigs i
Portland General Electric BNFL Inc.
71760 Columbia River Hwy.
90017* Street NW, Suite 1050
' Rainier, OR 97048 Washington, DC 20006-2501 Mr. Dan Gildow Mr. Max DeLong Portland General Electric -
Project Engineer 71760 Columbia River Hwy.
Private Fuel Storage, LLC Rainier, OR 97048 c/o NSP,512 Nicollet Mall j
Minneapolis, MN 55401 Mr. John Donnell Stone & Webster 7677 E. Berry Ave.
. Englewood, CO 80111-2137
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.h. Nuclear Regulatory Commission BFS/NRC 99-045, Attachment 1 Page1 NRC Part 71 Questions 5/18/99 Thermal 1)
Drawing CA-001 Sheet 1/3, Note 21, relates to chromium plating. How was chromium plating addressed in the design calculations and assumptions?
2)
Allowable manufacturing dimensions: Discuss any changes in dimensional gaps and the integration of such changes into the design calculations.
3)
Use of ANSYS Code: Which version of ANSYS was used (i.e., version 5.0 or 5.4)?
Discuss the different methods of nodalization that were utilized.
4)
Maximum cladding oxide thickness layer: Confirm the value for the maximum thickness layer for the cladding at temperature limit.
)
5)
Emissivity values: The tables in the SAR provide emissivity values for stainless steel at 400 F. Discuss how emissivity values were used in the design calculations for shell temperature (which equaled 211 F). How was conservatism incorporated?
6)
Section 3.3.7 of the SAR: The peak excursion temperature was noted to be 530 F for 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. Was this parameter evaluated in the coatings report? Ifit wasn't, why not? Ifit was, discuss the evaluation.
Materials i
7)
Section 3.3.4 of SAR (pg. 3-18): BFS takes exception to the ASME Code relative to i
temperature limit excursion. What is the impact of temperature limit excursion on plastic deformation limits?
8)
Section 8.1.4.3 of SAR (pg. 8-7): BFS discusses initial acceptance conditions of the impact limiter components. Discuss periodic inspection requirements of the assemblies and address the assurance that no degradation will occur in service due to weather, corrosion, etc. Is the assembly sealed, breathable, or open?
9)
Drawing SAR-71-002 Sheet 1, Note 10, indicates that all other welds are made in accordance with ASME Section IX. However,Section IX is not a construction code.
Therefore, provide a reference to the appropriate article in ASME Section III or to another construction code.
,. U.S. Nuclear Regulatory Commission 4
BFS/NRC 99-045, Attachment 1 Page 2 '
10).
Different materials used in construction: Provide a schedule of filler material types for
- corresponding base metals.
- 11)
Welding: Drawing SAR-71-003 Sheet 1, Notes 1 and 2, references AWS Dl.1 Code for
. welding. This code reference is not mentioned in the SAR as applicable for construction.
Ifinvokeds it is not applicable for welding stainless steel. Clarify this discrepancy and verify that references to applicable welding codes, including exceptions, in the SAR are correct.
1 a
12)
Drawing SAR-71-004 and others: Varying grades of stainless steel with differing mechanical properties are used in construction. No discussion is provided regarding the
' effects of variation in material properties on structural design. Discuss the effects of different strengths, weld material requirements, and critical flaw size allowances.
13)
Drawing SAR-71-005 Note 2 relates to penetrant test intervals for critical flaw size. No basis is provided for this parameter. Was this basis provided with the Part 72 Storage -
application? If so, there is no need to re-submit it for Part 71.
14)'
Cell assembly material A-500 Carbon Steel: ASTM Note I warns that this material may not be suitable where low temperature notch toughness properties are important. Given this caution, what damage to the' cells can be anticipated following a drop accident?
15)
A588 is a high strength, low alloy material: What are the filler material and preheat requirements? Consider impact test results and low temperature properties in your response.
16)
Coatings report and boric acid tolerance at elevated temperatures: How long was the j
material held at 211*F7 j
17)
Coatings report, pg. 2.1.4,' discusses the calculation of neutron exposure. Did the radiation test include neutron exposure? If so, include a discussion in the report. If not, why not.
18)
Coatings report, pg. 2.3.3 concluded that radiolytic decomposition for inorganics was not provided. Give the basis for this conclusion.
1
- 19) --
Coatings report, pg. 2.3.4: Clarify the meaning of" hypothetical fire accidents" of 1200 F and 520 F.
20)'
Coatings report: Provide the details of the radiation exposure test.
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_U.S. Nuclear Regulatory Commission.
l BFS/NRC 99-045, Attachment 1 Page 3 j
Containment l
21)
A shipping cask is not necessary for double containment given the limit of <20 curies of
22)
Section 8.1.3.3 discusses the procedure for pre-shipment leak testing around the vent port. Explain how the overall leak t' st accommodates the pre-shipment leak test and e
installation of the vent port.
23)
Section 8.1.3.3 Step 3 appears to be in error. The discussion involves drawing a vacuum on the cask cavity then leak testing. This should read "diaw vacuum on the space between the 0-rings,',' then conduct the leak test. Discuss.
7 24)
Section 8.1.3.2 Item 3: "lx10 " should be "lx10~7" 25)
Volume 4 RAI response page 1: The title of the table is incorrect.
26)
Provide a SAR drawing that highlights the containment boundary.
Shielding 27)
Basket length: The SAR indicates that basket length varies with the fuel type to be stored.
Provide a table of fuel types with corresponding basket lengths, specifying the size of the cask, the spacers, etc., to assure adequate coverage of poison plates with active fuel.
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28)
Personnel barrier: Why is credit taken in the shielding evaluation, in spite of the demonstration that dose rates are less than 200 mrem /hr? There may be surface temperature considerations. If credit is taken in the shielding evaluation, then provide data for survivability during a drop accident.
29)
For fuel types allowed, define the parameters. In Chapters 1 and 6 and in the calculation packages, consistency is not maintained for parameters of fuel types listed. Verify that the range of parameters is bounding. Some applications use the middle of the range, while others use the most conservative. Check the criticality calculations for consistency.
Criticality 30)
Keff results in calculation packages: Some values for keff are above the upper safety limit. Clarify. Review all criticality calculations for similar conditions.
31)
Figures 6.3.1 and 6.3.2 are unreadable as provided. Review the SAR for legibility of all
. figures, tables, and drawings for similar conditions, i
]
U.S. Nucicar Regulatory Commission BFS/NRC 99-045, Attachment 2 Page1 Summary of Trojan Differences The following provides an additional description cf the Trojan changes and a summary of the potential impact to the Part 71 application, including calculations and SAR drawings. This information is preliminary. The actual changes to the SAR drawings and calculations will be completed by the end ofJune 1999. Also, there is the potential for additional fabrication differences as baskets and other components are fabricated.
Basket Intemals Cell Material BFS will revise SAR drawing SAR-71-005 to reflect the use of either SA-516 Grade 70 or A-588 Grade A steel for the sleeve material. The motivation is to allow the A-588 material, with its higher strength, to be used as an option in fabrication. This option has no impact on the thermal analyses since the thermal properties (thermal conductivity, density, specific heat) of these two materials, given in the ASME Code, are the same. The existing structural calculations show that both materials are satisfactory. Use of the A-588 material provides larger margins to the allowable stresses.
Boral Attachment BFS will provide a new calculation, BNFLl.10.06.75, Rev. O, which evaluates the modified design for attaching the Boral sheets in the TranStor* PWR Basket with stainless steel strips and pins. The calculation shows that this poison sheet attachment design is adequate to withstand all design loads.
An additional new calculation, evaluating the effect of stainless steel strips used for the poison sheet attachment in the basket on the temperatures of the basket internals, will be provided. The preliminary results show that these strips have a minimal effect on the Helium filled basket. The results also show that the effect of these strips does not exceed a 2 F increase for the vacuum drying conditions. This is negligible compared to the available margin between the maximum temperatures calculated for the basket internals and their allowable temperatures.
SAR drawings affected are SAR-71-005, sheets 1,5,8, and 11.
I 1
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,. U.S. Nuclear Regulatory Commission BFS/NRC 99-045, Attachment 2
- Page 2 Main Cross Assembly Weld e
BFS will revise SAR drawing SAR-71-005, Sheet 4 of 12, to add a 3/16" fillet to the existing bevel weld of the main cross of the basket sleeve to be able to use higher weld quality factor per NG-3352 of ASME Code Section III.
Raised Shield Lid Plue An alternative shield lid plug and port cover plate were added to the design to reduce the dose rates around the vent and drain openings at the top of the TranStor Basket. No
. calculations were affected because the changes were conservative. The SAR drawings affected are SAR-71-004, Sheet 4 of 8 and SAR-71-005, Sheets 1 and 3 of 12.
Alternative Damaged Fuel Can Alternatives to the design provided in the Part 71 application include a sta.inless steel shell, a bolted lid, increased welding at the bottom plate, and an NDE change from PT to VT.
Potential changes include the addition of two calculations and two drawings, and a revision of calculation TSL01.10.06.69 and SAR drawings SAR-71-010 and SAR-71-012.
Alternative Debris Can The attemative design places 29 inch long,7.5 inch OD stainless steel cans loaded with debris into a 160 inch,8.5 inch OD stainless steel capsule that will be loaded into the alternative damaged fuel cans described above. Potential changes include one new SAR drawing with two sheets, one new calculation, and the revision of three calculations:
BNFLI.10.06.14, BNFLI.10.06.35, and BNFLI.10.06.50.
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., :. U.S.' Nucl:ar Regulatory Commission
.BFS/NRC 99-045, Attachment 3 Page1
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' LIST OF COMITMENTS 99-045-1 BFS will provide a response to each of these questions, including any necessary supporting information, such as revised drawings, calculations, and Safety
. Analysis Report (SAR) changed pages, by the end of June 1999.
99-045-2 BFS will provide a revision to its TranStor Part 71 application to integrate the Trojan differences by the end of June 1999.99-045 BFS will submit the results of the Impact Limiter Drop Tests by the end of August 1999.