RADTRAD Design, As Built,

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RADTRAD Design, As Built, Updates

• Terry Heames
• ALION Science and Technology
• presented at the
• NRR AST Workshop
• 22 June 2006

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Outline

• RADTRAD Design
• As Built
• Current Errors
• Modifications

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RADTRAD Design

• The 1994 model designed to do
• Use NUREG Spray and Natural Deposition models
  (Powers, Henry, or User)
• Overlying pool decontamination (Powers)
• Iodine re-evolution (ORNL)
• Filter decontamination (User)
• Transport (use but not derive flows)
• Onsite Offsite dose analysis
• NUREG 1465 and TID 14844 source terms
• It had numerical problems

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RADTRAD Design Reg Guide 1.183 1.195

• The 2002 release (3.03) designed to perform
• Spray and natural deposition decontamination
• Filter decontamination
• Transport
• Onsite Offsite dose analysis
• Correct known errors
• Follow the guidance in RG 1.183 1.195
• Provide reliable answers

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RADTRAD 3.03 As Built

• The 2002 version (3.03) was not designed to
  perform
• Iodine re-volatilization (pool)
• Pool pH versus time analysis
• Appendix I (Equipment Qualification)
• Filter failure and re-entrainment
• Decay of deposited isotopes
• AEB 98-03 steam line deposition or release

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RADTRAD 3.03 As Built

• The 2002 version (3.03) was not designed to
  perform the guidance efficiently
• LOCA, requires multiple cases (containment
  release, ESF release, and multiple X/Q paths).
  Steam line deposition, spray decontamination
  limits all offline.
• FHA, CRDA, LRA acceptable
• MSLB SGTR inventories available in Ci/cc or
  Ci/hr translate to Ci/MWt
• Nobles and Alkali Metals inventories 100/Ebar

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RADTRAD Error Notices

• 12 Error Notices since 6/2002
• First 5 were found between the release of 3.03 by
  ITSC and the release by the NRC.
• The NRC version has all these modifications.

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RADTRAD Error Notices

• 7 Control Room X/Q Time Intervals Ignored
  (7/04)
• 8 Powers Natural Deposition Model chooses
  PWR (10/04)
• 9 10 Compartments generates source term
  errors (10/04)
• 10 Inaccurate activities when decay of
  nuclides with lt 2 hr half lives. (12/04)

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RADTRAD Error Notices

• 11 Source term compartment without initial
  Iodine doesnt decay Tellurium correctly. (1/05)
• 12 Powers Natural Deposition inaccurate.
  (2/05)
• 13 Abrupt Flow Changes in Time causes dose
  inaccuracies. (3/05)

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RADTRAD 3.10 Modifications

• 3.10 allows path dependent X/Qs, to allow
  variation with release point and/or intake
• 3.10 allows use of a multi-bin/multi-volume,
  homogeneous, or slug deposition model MSIV
• 3.10 allows spray DF limits
• 3.10 decay and daughtering of deposited nuclides

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RADTRAD 3.10 Modifications

• 3.10 allows multiple inventory and release files
  to allow LOCA-ESF, MSLB, SGTRs to be run as
  single cases
• 3.10 edits activity (Ci) of airborne deposited
  nuclides in both compartments and paths.
• 3.10 edits exposure (Ci-hr) and decays of
  airborne nuclides for shielding and pH calcs.

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RADTRAD 3.10 Still Missing

• Average Beta and Gamma energies (base for pH,
  shine, and 100/Ebar analysis)
• Qualified Main Steam deposition model
• Re-entrainment model
• SI units for I/O

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•             Other than pain in generating the
  100/Ebar limit for non-iodines in the coolant,
  has anyone ever seen that it made a difference in
  the dose?  If not why add to the pile of
  information in a submittal?
•  
•             In one of the RAIs the NRC requested
  that the submittal use the total iodine released
  over the total amount currently in the atmosphere
  as the basis for a DF limit because it will
  decrease the time the sprays are on.  Are there
  calculations to show that this is important?  If
  one uses the correct definition of DF, i.e. the
  amount in the atmosphere the amount deposited
  over the amount in the air, the difference
  between the 2 definitions is at best less than a
  few minutes.  Why a concern?
•  
•             I know you do not like to go to far
  from where the data is but one of the submittals
  used a pool height of 19 for the computing the
  DF in a FHA.  The complaint was the basis point
  (i.e the DF at 23) but not the use of the
  approximation at such a low depth.  What is the
  level that is acceptable?
•  
•             There was a complaint about a
  shielding calculation where one set of pipes
  passed behind another and there was some space
  for additional shine to get through in the
  spaces.  Unless this is a particularly high
  activity situation, arent you worrying about
  small lt1 effects?

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Main Steam Line