Date: Fri, 29 Sep 2000 15:07:40 -0500
From: Jim Kilmer <kilmer@fnal.gov>
To: Greg Bock <Bock@fnal.gov>, Jim Hylen <hylen@fnal.gov>,
     Dave Pushka <pushka@fnal.gov>
Cc: Craig Moore <cmoore@fnal.gov>, David B. Augustine <augustine@fnal.gov>,
     Ernie Villegas <villegas@fnal.gov>, Jim Kilmer <Kilmer@fnal.gov>,
     Pat Hurh <hurh@fnal.gov>, Paul Czarapata <PCCEED@fnal.gov>
Subject: Comments on Minos target pile

Gentlemen,

Here are my comments on the review.  I've also appended all of the comments
from the other members of the team.

Jim Kilmer's list:
1.     How do you grab a T block remotely with the crane?  Needs to be done
in a radiation field later.
2.     I don't understand how T blocks are installed under transverse beams.
Write-up stated they were installed before carriage went in.  Then how does
the horn get past them?
3.     Should green and blue blocks standing on edge be tack welded together
to ensure stability of the structure?
4.     What supports the helium tubes?  Do they have to be removed (or
moved) to get out a horn?
5.     I'm worried about the air cooling flow rate in the chase too.  Note
that from Dave's talk if you consider the clear flow area cross-section you
get 71 mph and not 30 mph.
6.     A concern was raised in the meeting about methods required to keep
crane controls functioning in the high radiation field.  Think NM2.
7.     It was mentioned that H blocks might have to be purchased.  Two items
are noted.  a)  If blocks are purchased try to get low sodium concrete
blocks.  b)  We used a large number of H blocks in HIL for E-872.
8.     There was discussion about whether the present location of the
prototype horn would be available for future horn work.  This should be
sorted out quickly by Beams Division and for the life of the experiment.

Paul Czarapata's list:

Actually I think you had them in your comments. i.e. An
instrumentation/electrical engineer should be brought into the game now so
that any instrumentation that is desired can be incorporated now and not
have
to be "kludged" on to the final product.  Issues such as cable routing,
sensor
mounting etc. should be handled up front.
Paul

Dave Augustine's list:

My main concern was the tunnel temp, humidity ,and wet floors. At that
elevation water will slowly leach into the tunnel. Air flow must be enough
to evaporate it. De-humidifiers must be enough to dry the air to a
reasonable level, 50%. Hugh amounts of new air is introduced into the tunnel
to cool the shield steel. A paddle wheel type de-humidified is planned. I am
assuming that the 100 degree waste heat is being dumped into the tunnel for
heat as well.

Ernie Villegas' list:

Just a few notes concerning the Numi target pile review.

1)  From the point of view of a first time observer, the design
    seems well beyond the conceptual stage. Still,there is a great
    deal of engineering/design/fabrication work that has to be completed
    within the next two years. I would question whether enough manpower
    allocations have been made to this area. In particular I was surprised
    to hear that electrical engineering has not been involved to date.

2)  Power connections to the horns(striplines?) do not seem to be well
    define.

3)  The work required to finalize the controls for the modules is just
    begging for engineering support.

4)  Given the lack of dimensional precision and weight (10 tons) for the
    shielding steel blocks, has Enough manpower been devoted to this task?
    Five per day seems fine at first glance, but maybe a closer look would
    indicate a slower rate of progress.

Pat Hurh's list

Here's a summary of my comments from the review:

General:

Overall, I see no major holes or 'show-stoppers' in the plans
presented. It should be noted that the plans presented were conceptual
designs with only portions of detailed design complete. There are
several issues that require detailed engineering and designing, but
overall the concepts presented seem sound. I think the only general
concern that I have is the amount of manpower and other resources that
are required to complete the Target Hall on schedule. It is clear that
additional engineering, drafting, and technician support is needed to
complete the detailed work successfully on schedule.

Specific:

Some details that need significant attention:

1) Chase Shielding Installation - The geometrical tolerances of the
Duratek steel blocks are large enough to require individual shimming,
fitting, and grouting of each block. Because of the weight and numbers
of blocks required and the deep locale of the target hall,
installation will be a major project by itself. Blocks should probably
be measured and classified into tolerance groups ahead of installation
to ease selection and fitting. Blocks can also be classified according
to chemical content so that blocks undesirable for radiological
reasons can be placed in locations of least impact. Mechanisms and
devices to tow the blocks from the shaft to the chase must also be
carefully developed.

2) Target Hall Access Procedures - Although detailed procedures cannot
readily be produced for Target Hall accesses (i.e. to change a horn
location), general procedures which outline the steps involved for
major accesses should be developed now. These procedures will help
engineers and designers visualize how their designs will be utilized
in practice and ensure that enough flexibility in the Target Hall
design is provided to accommodate needed tasks. Special attention
should be paid to the musical chairs game that will be played with
filler tee-blocks and modules.

3) Alignment of Target Hall components - Although absolute placement
of the components can be done to the given tolerances (.020" )
initially, over time the alignment may shift out of tolerance due to
thermal expansion/contraction and mechanical backlash/hysteresis. The
thermally hot areas (especially at Horn 1 module) should be looked at
carefully to see how they affect alignment of the components. Cooling
and/or thermally isolating the Horn 1 support shafts should be
considered to minimize vertical thermal motion of the Horn. A strung
wire system with capacitive pick-ups looks like a promising idea to
provide absolute referencing of the components over time (esp.
horizontally).

4) HVAC - The plan presented seemed feasible to cool the shielding
blocks and keep the poured concrete thermally stable. The high air
velocities in the chase seem surprising, but theoretically doable. In
practice, engineers and designers must be careful to make sure that
additional loadings on all components in the Target Chase are taken
into account. Small instrumentation wires and other non-rigid
structures could see extreme buffeting from the 32 mph winds
predicted. Installation workers also must be careful to ensure that
all air leaks are minimized (ensure flow through chase) and that
channels between concrete and steel (especially at the bottom) remain
clear and free. During operation failure of the sump system may mean
that the lower air passages could be blocked with water (?) this
should probably be looked at.

The actual ducting and HVAC equipment has not yet been finalized.
Obviously care must be taken in order to make sure the resulting
system is easily configured and balanced for the as built geometries.
In addition, a system to collect and test condensate for irradiation
must be developed and implemented.

5) Hot Work Cell Equipment - Lift tables, shielding issues and remote
manipulation issues must be addressed for this area. It is important
to predict what operations can be done and can't be done using this
facility so that engineers and designers don't just assume that some
task can be done in the Hot Work Cell.

6) Flexible Stripline Joint - Although this probably isn't technically
part of the review panel's charge, it looks like the biggest technical
unknown at this time. Engineering resources should be brought to bear
as soon as possible on this problem. A possible 'plan B' described
during the review was to move the entire stripline module with the
horn. I don't think that is a particularly attractive idea because of
the loads placed on the horn support. I think a possible back-up plan
would be to automate the stripline hard connection at the bottom of
the module so that when the horn is moved the joint is loose. However,
welding of the connection under many high current pulses could
complicate that mechanism.

7) Instrumentation and Controls - There seemed to be a lack of
information about sensing devices and control systems for the various
motion devices. Electrical Engineering support should be added to
address these issues at this time. It is preferable to have these
issues settled early so that accommodation of the needed devices can
be made by the mechanical designers.

Craig Moore's list:

,

      These are some of the concerns/issues that I have from the review:

The question of the relative alignment of the devices once they are out
of sight.  If a beam based alignment scheme can be used in a relatively
straightforward way without a great deal of time, then a lot of my
concern is obviated, and there is probably enough steering to hit the
center line of the elements if they are on a line.  However being able
to remotely monitor the relative motion of the objects while the
temperature us changing could be very useful (and reassuring).  It is
clear that the horizontal motion is of the most concern.  At the least,
being able to check the elements by using removable plugs in the
shielding seems a good idea; and at the most, having a remote readout
system based on stretched wire techniques, laser techniques, or other
techniques would be ideal.

I understand that the force of the 30 m.p.h. air flowing down the chase
is not much but I would still worry about turbulence and the inducement
of normal mode oscillation of the hanging elements.

The question of neutron leakage through the uneven blue/green blocks
needs to be looked at.

If additional concrete shielding blocks need to be purchased then
finding out how much extra it would cost for low sodium concrete would
be useful.