Persuant to our several discussions relative to the failure of the fuel
cylinder of the Raleigh Research Reactor, we have dismaulted the assembly and
arranged to send it to the Oak Ridge National Laboratory in accordance with the
arrangements you have made for examination of the core and disposal of the
contaminated components.

One of our staff members will accompany the shipment of reactor
components from Raleigh, we are sending the material on one of our trucks, and
in accordance with instructions and advice from Mr. McAulderf, of your office.
A separate letter will contain details of the shipping arrangements.

I list below the specific operations involved in handling the various
materials sent, and the data which seem to us should be obtained from
the components.

• 1. Disposal of waste with trace contamination:

  One or two containers will contain paper, gloves, kleenex
  and other miscellaneous materials contaminated with traces of
  fission product activity. The major portion of this can be disposed
  of by incineration.

  The principal shipping container for this material is the
  2 1/2' x 3' x 5' aluminum safety envelope which enclosed the reactor
  mechanism. The outside of this envelope is uncontaminated, but the
  inside has adherent surface activity. The loosely adherent material
  was removed, and most of the remainder could be removed by further
  treatment. However, this envelope is to be replaced, and hence
  this item may be scrapped and disposed of as the Laboratory may
  desire.

• 2. Disposal of highly contaminated components:

  Disassembled sections of the gas handling system were
  placed at the center of 55 gallon drums which were then filled
  with concrete. These containers are to be disposed of without
  any attempt at recovery or examination.

• 3. Recovery of Uranium for inventory and accountability purposes:

  It is estimated that as much as 20 grams of U235 may be
  contained in the components and rinse-liquids included in this
  shipment. The usual care and attention should be given to
  retention, extraction and recovery of this uranium. Its location
  is:

  • (a) Inside the fuel cylinder: a small amount of liquid
    remains in the core; uranium may be deposited on the inside
    metal surfaces; some uranium peroxide precipitate may be in
    the bottom of the core or deposited on the surfaces.
  
  
  • (b) Inside the 11" diameter, 30" deep aluminum safety
    envelope thimble which snugly enclosed the fuel cylinder in
    its lower portion. Fuel solution did escape into the annular
    space and shim-rod pockets in this envelope. Attempts to wash
    this out were not successful. Some wash liquid (500 cc or so)
    remains in this spaced. The fuel cylinder, also, is in place,
    not having been removed for fear of undue spreading of
    contamination. Above the fuel cylinder in the envelope thumble
    the space is filled (a) with sheaths and tubes which attach to
    the core, and (b) packed graphite pillets and rods, (c) contained
    in several bottles of rinse-solutions which were used to reduce
    the fuel and fission product activity inside the core and
    envelope thimble, (d) on the surfaces of the two shim-rods
    (flat, 4" wide cadmium sheets clad with thin aluminum).

• 4. Examination of the Fuel Cylinder:

  The basic object of this examination is to determine why
  failure occurred and to obtain any data which might assist in
  the design of improved fuel containers.

  Evidence clearly indicates the presence of at least two
  separate defects which seemed to occur at approximately the
  same time. (a) One is in one of the four cooling tubes. This
  is a small leak. In pressure tests, 50 pounds of pressure on
  water inside the sealed off coils showed a negligible drop in
  several hours; 30" of Hg vacuum on the sealed off coils showed
  a slow rise over a period of hours. It is suggested that the
  four coils be removed intact from the sectioned cylinder for
  testing and examination as to the location and cause of the
  defect. At some point in the study, a look should be taken
  at the inside surface of a cooling coil as well as the outside
  surface. (b) The second leak is in the exterior wall of the
  cylinder. At least a considerable amount of fuel solution
  seems to have escaped into the annular space around the cylinder.
  Heavy contamination was found on the shim-"rods", and some
  clue to the depth of liquid in the annular space may be gained
  by examination of the surfaces of these "rods". There is a
  "butt" weld in the vertical wall of the cylinder, one inch from
  the lower end where the shaped bottom and the wall of the cylinder
  were joined. The lid was welded on at the top. Fifteen tubes
  connect to or project through the top surface of the cylinder.
  All are welded in place.

• It is not know, of course, where the leak in the cylinder
  is or why it occurred. There are the welded points which may
  have been defective, a defect in the metal components is by
  no means impossible, there was a tendency of the fuel to
  precipitate as uranium peroxide which may have caused unexpected
  corrosive attack; finally, there was on record one fairly large
  pressure surge and one or two smaller ones over the preceding
  months due to erratic operation of the catalyst in the gas
  recombiner system.

  If corrosive attack is found to be the cause of the defect,
  any clues to the reason for this attack should be sought.

• 5. Analysis of a fuel sample.

  One small sample of the fuel solution removed from the
  reactor core and placed in storage is included in this shipment.
  It is anticipated that a careful analysis of this for anomalous
  components, metallic ions, evidence of UO4 precipitate, etc.
  may give some clue to the corrosive action which may have
  occurred inside the fuel cylinder.

  This analysis has particular importance for it may indicate
  whether or not the fuel solution should be reprocessed before
  it is placed again in the reactor.