ATTACHMENT 3

  

APR-21-1995  15:12  K-25 CLASSIFICATION OFC.      P.05/08

               MANHATTAN DISTRICT "SECURITY MANUAL"
                           Nov. 26, 1945

Section III.

     (1)  Documents containing specific design details
(diagrammatic or descriptive) of complete basic or key equipment,
apparatus, instruments, or machinery employed in a critical stage
of the processing and production of and products, or the methods
of manufacture (where unique to the Manhattan District) of such
items; also, the material itself, as described above.

     (2)  Documents containing complete uncoded flow sheets,
diagrams, or reactions, including specific pressures,
temperatures, voltages, rates, formulae, and other operating
details not described in the Smyth* Report, specifically related
to a critical step in the preparation, processing, separation, or
purification of basic feed materials, and principal and products.

     (3)  Documents containing unique nuclear, physical, and
chemical characteristics of and products, and critical process
materials (including, for example, barrier material and neutron
moderators), and also details of the manufacture (where unique to
the District) of such materials.  Also the products and materials
themselves when they disclosed such information.

     (4)  Documents showing the meaning of a name or symbol used
as a code, where the code name or symbol refers to matters
classifiable as SECRET.

     (5)  Documents pointing out the existence of unique
operational or production hazards, their nature and solution.

     (6)  Details pertaining to features of special shipping
containers, routes and schedules of shipments of Secret
materials, except as classified TOP SECRET.

     g.   Confidential Matter:  Information, or features
contained herein, the disclosure of which although not
endangering the national security, might be prejudicial to the
interest or prestige of the United States, a governmental
activity, or an individual, or be of advantage to a foreign
nation, is classified as CONFIDENTIAL.  Confidential shall
include items of the following nature:

     (1)  Documents containing specific design details
(diagrammatic or descriptive) of incomplete components of basic
or key equipment, apparaus, instruments, or machinery employed in
a critical stage of the processing and production of and
products, or the methods of manufacture (where unique to the
District) of such items.  Also the material itself, as described
above.

*"Atomic Energy for Military Purposes" by H.D. Smyth, 1945.

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