ML13091A006

University of Texas, Austin, Response to Request for Additional Information to New Fuel Storage License Renewal

ML13091A006
Person / Time
Site:	University of Texas at Austin
Issue date:	03/22/2013
From:	Biegalski S, Whaley P University of Texas at Austin
To:	Patrick Boyle Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME7694
Download: ML13091A006 (6)

Text

) Department of Mechanical .Engineering THE UNIVERSITY OF TEXAS AT AUSTIN Nuclear EngineeringTeaching Laboratory .Austin, Texas 78758 74512-232-5370 FAX 512-471-4589 - http://www.me.utexas.edu/-netL/

SAUS5 March 22, 2013 ATTN: Document Control Desk, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 Patrick Boyle Project Manager Division of Policy and Rulemaking Research and Test Reactors Licensing Branch

SUBJECT:

Docket No. 50-602, Request for Renewal of Facility Operating License R-129 REF: UNIVERSITY OF TEXAS AT AUSTIN - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE LICENSE RENEWAL REQUEST FOR THE NUCLEAR ENGINEERING TEACHING LABORATORY TRIGA MARK II NUCLEAR RESEARCH REACTOR (TAC NO. ME7694)

Sir:

The response regarding a request for additional information relative to new fuel storage is provided below.

RAI 20.2: During a site visit, the NRC staff noted that fuel elements are stored in what appears to be a non-standard rack for which no analysis is provided in the UT SAR. Please identify all locations covered by the license where fuel elements are stored, identify the types and numbers of fuel elements that are stored, provide details concerning the storage rack or bin geometry, and analysis that demonstrates that such racks or bins provide adequate conditions for storage.

RESPONSE

As part of the Department of Energy Voluntary Security Enhancements program for domestic facilities, safes have been acquired to support storage of new fuel, and will be fully implemented prior to completion of the relicense process. Potential safe movement will be limited by mass/weight. Fuel elements will be stored within the safes in a rectangular array defined by penetrations in a material that rests on shelf supports; potential movement of the array structure will be limited by clearance between the material and the inner walls of the safe. Potential for movement of fuel elements within the array will be controlled by clearance between the surface of the protective cardboard tube and the penetration.

Empty weight of the fuel safes is approximately 800-1000 Ibs, limiting potential for unintentional or uncontrolled movement. The nominal maximum diameter along the length of the fuel element is 1.495 in. New fuel elements are delivered in sealed cardboard tubes approximately 1/16 in. thick that protect the fuel element M(~L

surface during transportation and handling prior to use. Sleeves cover each end of the tubes, increasing clearance requirements. A 2-in. radial clearance along the surface provides approximately 3/16 in. form the circumference of the cardboard tube (with end caps reducing the clearance) and can be manufactured with standard tooling.

Therefore, penetrations in the material will be 2 in. (6.35 cm) diameter with center to center fuel element distance 2.5 in. (6.35 cm). There will be no loading normal to the material surface.

Criticality analysis was performed using SCALE (CSAS6 sequence), sample input file using ENDF 7 (release 0) continuous energy cross section library attached and assuming the safe adjacent to a concrete wall, resting on a concrete floor (Fig. 1). Free air spaces surrounding and within the safe are assumed to be filled with water, as the condition of optimal moderation. Results indicate that kf for a completely fill lattice is 0.78902 + 0.00073.

Figure 1: Room and Safe Figure 2: New Fuel Figure 3: New Fuel Figure 4: Lattice Top View Safe End View Safe Front View Calculations of kff based on the design of the array are conservative in assuming a water environment and full lattice is assumed. New fuel storage at UT is well above the ground floor, limiting potential for a water-filled environment. A fully charged lattice is enough fuel for approximately Y of a TRIGA core; UT currently has approximately 20% of the assumed loading, and does not anticipate potential for acquiring %of a new core.

We respectfully request an additional 90 days to complete response to the remaining items. If there are any questions, please feel free to contact P. M. Whaley at 512 232 5373 or whaley@mail.utexas.edu.

Your attention in this matter is greatly appreciated, P.M.W P. .

dcrpenal of perjury that the foregoing is true and correct.

S. Biegalski

ATTACHMENT 1: SCALE INPUT FILE, NEW FUEL STORAGE CRITICALITY ANALYSIS

'Input generated by GeeWiz SCALE 6.1 Compiled on Mon Jun 6 11:04:33 2011

=csas6 ut triga new fuel storage: steel safe on concrete floor, concrete wall ce v7 endf read composition zr-zrh2 1 5.393206 300 end h-zrh2 1 0.09534004 300 end u-235 10.1009533 300 end u-238 10.4089117 300 end zirconium 2 0.961169 300 end graphite 3 0.75 300 end dry-air 41300 end aluminum 5 1 300 end ss304s 6 1 300 end h2o 7 1 300 end oak 8 1300 end reg-concrete 9 1 300 end end composition read parameter gen=3000 npg=350 nsk=30 htm=no end parameter read geometry global unit 1 com="unit 1: concrete in room and walls" cuboid 10 600 -600 600 -34.925 600 -34.925 cuboid 20 600 -600 600 -34.925 -4.445 -34.925 cuboid 25 600 -600 -6.35 -34.925 600 -4.445 cuboid 30 75.885 -4.765 56.9 -6.35 149.225 -4.445 hole 2 media 7 1 10 25 media 9 1 20 media 9 1 25 boundary 10 unit 2 com="unit 2: safe" cuboid 30 75.885 -4.765 56.9 -6.35 149.225 -4.445 cuboid 31 71.12 0 42.93 0 144.78 81.28 cuboid 32 71.12 0 42.93 0 81.28 0 array 1 32 place 1 11 -2.4 -3.81 0 media 6 1 30 32 media 7 1 31 boundary 30 unit 3 com="unit 3: lattice structure, without hole for inserting fuel" cuboid 30 6.35 0 6.35 0 81.28 0

cuboid 41 6.35 0 6.35 0 11.43 10.16 cuboid 42 6.35 0 6.35 0 52.07 50.8 media 7 1 30 42 media 8 1 41 media 8 1 42 boundary 30 unit 4 com="unit 4: lattice position, empty" cuboid 30 6.35 0 6.35 0 81.28 0 cuboid 41 6.35 0 6.35 0 11.43 10.16 cuboid 42 6.35 0 6.35 0 52.07 50.8 cylinder 50 2.54 81.28 0 origin x=3.175 y=3.175 z=O media 7 1 30 42 -50 media 7 1 50 media 8 141 -50 media 8 1 42 -50 boundary 30 unit 5 com="unit 5: lattice position, cardboard and fuel (via hole)"

cuboid 30 6.35 0 6.35 0 81.28 0 cuboid 41 6.35 0 6.35 0 11.43 10.16 cuboid 42 6.35 0 6.35 0 52.07 50.8 cylinder 50 2.54 81.28 0 origin x=3.175 y=3.175 z=O cylinder 51 2.0359 68.733 0 origin x=3.175 y=3.175 z=O cylinder 52 1.8771 68.733 0 origin x=3.175 y=3.175 z=O hole 6 origin x=3.175 y=3.175 z=35.97 media 7 1 30 42 -50 media 8 1 41 -50 media 8 1 42 -50 media 7 1 50 -51 media 8 1 51 -52 media 7 1 52 boundary 30 unit 6 com="unit 6, new fuel element" cylinder 20 1.8771 32.5374 -34.0741 cone 40 0.635 32.5374 1.8771 27.4574 cylinder 41 1.8771 27.4574 -28.5013 cylinder 42 1.8263 26.8224 -27.8663 cylinder 43 1.7183 25.5524 19.05 cylinder 44 1.812 19.05 -19.05 cylinder 45 0.3175 19.05 -19.05 cylinder 46 1.7183 -19.05 -19.1287 cylinder 47 1.7183 -19.1287 -27.8663 cone 50 1.8771 -28.5013 0.635 -34.0741 media 7 1 20 41 -50 media 6 1 40 media 6 1 41 -42 media 4 1 42 44 47 media 3 1 43 media 1144 -45 media 2 1 45 media 5 1 46

media 3 147 media 6 150 boundary 20 end geometry read array ara=1 nux=12 nuy=8 nuz=l typ=square fill 3 3 3 3 3 3 3 3 3 3 3 3 3 5 5 5 5 5 5 5 5 5 5 3 3 5 5 5 5 5 5 5 5 5 5 3 3 5 5 5 5 5 5 5 5 5 5 3 3 5 5 5 5 5 5 5 5 5 5 3 3 5 5 5.5 5 5 5 5 5 5 3 3 5 5 5 5 5 5 5 5 5 5 3 3 3 3 3 3 3 3 3 3 3 3 3 end fill end array end data end

Please contact me by phone at 512-232-5373 or email whalev@mail.utexas.edu if you require additional information or there is a problem with this submittal.

Thank you, P. M. Whaley Associate Director Nuclear Engineering Teaching Laboratory The University of Texas at Austin I declare under penalty of perjury that the foregoing is true and correct.

Executed on December 12, 2012 Steven R. Biegalski NETL Director Al-: 1. Report on Neutronic Analysis of the UT TRIGA Reactor

2. Historical UT TRIGA Core data