United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9511150265

Rosemount Nuclear Instruments      Rosemount Nuclear Instruments, Inc.
                                   12001 Technology Drive
                                   Eden Prairie, MN 55344 USA
November 10, 1995                  Tel 1 (612) 828-8252
                                   Fax 1 (612) 828-8280

Re:  Notification under 10 CFR Part 21 on Rosemount Nuclear Instruments,
     Inc.  Model 1159 Remote Seal Systems with DC 704 Fill Fluid.

Pursuant to 10CFR21 Paragraph 21.21(b), Rosemount Nuclear Instruments,
Inc. (RNII) is writing to inform you that the Model 1159 Remote Seal
System may not perform in accordance with published specifications when
used with DC 704 fill fluid.  The potential for performance degradation
is caused by the reaction at certain ambient temperatures of DC 704 fill
fluid with Rando HD-46 machine fluid residue located on the remote seal
housing.  The reaction between DC 704 fill fluid and Rando HD-46 machine
fluid may result in outgassing of the DC 704 fill fluid causing a zero
shift in the output of the transmitter/remote seal assembly.

RNII Model 1159 remote seal systems are qualified per IEEE Std. 323 and
344 when used with RNII Model 1152, 1153, and 1154 transmitters.  By
design, Model 1159 remote seal capillaries are filled with fluid at the
RNII factory and cannot be filled in the field.  The standard remote seal
fill fluid offering is water.  RNII offers DC 200 and DC 704 fill fluids
as optional fill fluids.

RNII has been advised that a transmitter/remote seal with DC 704 fill
fluid failed in a commercial (non-nuclear) application.  The failure mode
was a continuous shift in transmitter zero when the remote seal was
subjected to ambient temperatures in excess of 500 degrees F (260 degree
C).  Subsequent failure analysis concluded the cause for the shift in
zero was due to the DC 704 fill oil outgassing from a reaction to
machining fluid residue on the remote seal housing.  The machining fluid
was identified as Rando HD-46.  Rando HD-46 is used by the supplier of
remote seal housings as a machine lubricant on machinery used to
manufacture the parts.  This machining fluid is formulated to act as a
corrosion inhibitor by leaving a residue on the part.

RNII is not aware of any failures of this type in nuclear power plant
applications.  However, Model 1159 nuclear grade remote seal housings are
purchased from the same supplier as the RMD parts and therefore could
contain the same machine oil residue.  RNII has conducted tests using all
three Model 1159 fill fluid options; water, DC 200 and DC 704.  From the
testing, RNII has concluded that Rando HD-46 reacts only with DC 704 fill
fluid where transmitter output can be affected.

FISHER-ROSEMOUNT

10CFR21 Notification
Model 1159 Remote Seal Assembly
November 10, 1995
Page 2 of 4

Laboratory analysis of DC 704 reacting with Rando HD-46 indicates that a
reaction between fluids begins at 122 degrees F (50 degrees C) and
accelerates beginning at 446 degrees F (230 degrees C).  RNII has
completed testing of transmitter/remote seal assemblies with DC 704 fill
fluid which monitored transmitter output for 28 days at an ambient
temperature of 200 degrees F (93.33 degrees C).  Test results showed no
adverse affect on transmitter zero.  RNII does not have sufficient data
to determine the effect on transmitter output at ambient temperatures
between 122 degrees F (50 degrees C) and 446 degrees F (230 degrees C).
We conclude that since a reaction is present, outgassing of the DC 704
fill fluid can occur, and therefore a potential progressive zero shift is
possible.

1.0  Name and address of the individual providing the information:

     Mr. Mark Van Sloun
     Vice President & General Manager
     Rosemount Nuclear Instruments, Inc.
     12001 Technology Drive
     Eden Prairie, MN 55344

2.0  Identification of items supplied:

     Model 1159 Remote Seal Assemblies, with DC 704 Fill Fluid, supplied
     as a configured system with model 1152, 1153 or 1154 transmitters.
     The list of units is referenced in the enclosure entitled Attachment
     A.  Remote seal assemblies with DC 704 fill fluid are identified by
     the "B" character at the end of the model number.  (e.g. 1159A10B).

3.0  Identification of firm supplying the item:

     Rosemount Nuclear Instruments, Inc.
     12001 Technology Drive
     Eden Prairie, MN 55344

4.0  Nature of the failure and potential safety hazard:

     This notification is issued to inform all users of Model 1152, 1153
     and 1154 transmitters with Model 1159 Remote Seal Assemblies,
     configured with DC 704 fill fluid, of the potential for zero shifts
     outside normal design specifications.  The zero shift is caused from
     the reaction of the DC 704 fill fluid with a machining fluid
     residue, Rando RD-46, which remained on the remote seal housing.

     RNII does not have sufficient information to determine the safety
     impact related to plant applications.  Licensees must determine the
     impact on plant operations and plant safety and take action as
     deemed necessary.

FISHER-ROSEMOUNT

10CFR21 Notification
Model 1159 Remote Seal Assembly
November 10, 1995
Page 3 of 4

5.0  The corrective action which is taken, the name of the individual or
     organization responsible for that action and the length of time
     taken to complete that action:

     RNII has concluded that DC 704 fill fluid reacts with machine oil
     Rando HD-46 at ambient temperatures as low as 122 degrees F (50
     degrees C).  Although RNII has not confirmed any field failures at
     nuclear plant applications, RNII has been advised of one field
     failure of a commercial (non-nuclear) transmitters/remote seal
     systems using DC 704 fill fluid at ambient temperatures over 500
     degrees F (260 degrees C).

     RNII Actions:

     1.0  Under Corrective Action Request (CAR) 95-0048, RNII will
          eliminate the use of Rando HD-46 machining oil in the supply of
          these parts.  The scheduled implementation date is December 1,
          1995.  This will eliminate the potential failure mode for
          future transmitter/remote seal assembly shipments.

     2.0  Remedial action has been taken to remove Rando HD-46 from all
          applicable parts in current stock.

     User Actions:

     1.0  Users with affected transmitter/remote seal assemblies
          installed in plant processes have the following options:

          A.   Trend transmitter output for observation of zero shift
               outside design specifications.

          B.   Remove from service and replace with new transmitter/
               remote seal system.

     2.0  Users with affected transmitter/remote seal assemblies located
          in stores can return the units to RNII for replacement of the
          remote seal assembly.

     Mr. Van Sloun is responsible for any further action related to this
     issue.

FISHER-ROSEMOUNT

10CFR21 Notification
Model 1159 Remote Seal Assembly
November 10, 1995
Page 4 of 4

6.0  Any advice related to the potential failure of the item:

     No further information is forwarded.

RNII has a strong commitment to the nuclear industry and assures you that
we are dedicated to the supply of high quality products and services to
our customers.  If there are any questions, or you require additional
information related to this issue, please contact Tim Layer (612)
828-8240 or Jane Sandstrom and Ian Baldry (612) 828-8250.

Sincerely,

Rosemount Nuclear Instruments, Inc.

M. L. Van Sloun
Vice President & General Manager

encl.: Attachment A

MVS:TJL

FISHER-ROSEMOUNT

ATTACHMENT A "MODEL 1159 REMOTE SEAL" Sheet 1, Page 1, omitted.

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