United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #:  9501270185

Fax

Sent via FaxWorks OS/2

To:
     Document Control Desk
     U.S. Nuclear Regulatory Commission

From:
     Robert M. Schroeder
     Dow Corning Corporation
     517/496-8330 (voice)
     517/496-5849 (fax)

2 pages (including this cover sheet)
Sent on 24-Jan-95 at 11:57

Comment:
     The following letter was sent to our
     customers today


DOW CORNING

January 23, 1995

                                                                 By FAX

RE:  Update on SYLGARD (Registered Trademark) 170 Silicone Elastomer,
     SYLGARD (Registered Trademark) 170 Silicone Fast Cure Elastomer, and
     DOW CORNING (Registered Trademark) 96-081 RTV Adhesive/Sealant

Dear Sir or Madam:

Dow Corning made the following progress since our last communication to
you on 1/6/95:

DOW CORNING (Registered Trademark) 96-081 RTV Adhesive/Sealant Dow
Corning has completed trial runs of DOW CORNING (Registered Trademark)
96-081 RTV Adhesive/Sealant incorporating the higher purity grade
pigment.  Lot acceptance testing confirmed that the material produced
with the higher purity grade pigment meets all of our sales
specifications. Therefore, we are once again capable of supplying DOW
CORNING (Registered Trademark) 96-081 RTV Adhesive/Sealant which meets
all of our sales specifications.  Material should be available no later
than the end of February.

Underwriters Laboratories Dow Corning has met with Underwriters
Laboratories and identified appropriate fire performance tests to
evaluate the SYLGARD (Registered Trademark) 170 Silicone Elastomer,
SYLGARD (Registered Trademark) 170 Silicone Fast Cure Elastomer, and DOW
CORNING (Registered Trademark) 96-081 RTV Adhesive/Sealant in question. 
Testing will be completed in mid May.  A final report documenting the
test results will be issued by the end of May.

Our next update will occur no later than April 7, 1995 to provide a
progress report on testing.  If you have questions, please contact me on
our Information Line for this matter (517) 496-8777.

                              Robert M. Schroeder
                              Fire Protection Engineer
RMS:jml
cc: NRC

DOW CORNING CORPORATION, 
MIDLAND, MICHIGAN 48686-0995                 TELEPHONE: (517) 496-4000


GENERAL INFORMATION or OTHER             EVENT NUMBER: 28079

LICENSEE: DOW CORNING CORPORATION        NOTIFICATION DATE: 11/28/94
    CITY: MIDLAND        REGION: 3       NOTIFICATION TIME: 17:26 [ET]
  COUNTY:                 STATE: MI      EVENT DATE:        11/28/94
LICENSE#:             AGREEMENT: N       EVENT TIME:        12:00 [EST]
  DOCKET:                                LAST UPDATE DATE:  01/24/95

                                                NOTIFICATIONS

NRC NOTIFIED BY: FACSIMILE
HQ OPS OFFICER: WILLIAM HUFFMAN

EMERGENCY CLASS: NOT APPLICABLE
10 CFR SECTION:
CCCC 21.21     UNSPECIFIED PARAGRAPH

                               EVENT TEXT

PROBLEM WITH DOW CORNING SUPPLIED SILICONE ELASTOMERS.

DOW CORNING OF MIDLAND, MICHIGAN, NOTIFIED THEIR CUSTOMERS
(SUPPLIERS TO
NUCLEAR UTILITIES) OF A PROBLEM WITH CERTAIN SILICONE ELASTOMERS. 
THE
ELASTOMERS HAVE EXPERIENCED DEVIATIONS IN THE SPECIFIED CURE RATES. 
IT
IS NOT YET KNOWN IF THE DEVIATIONS AFFECT THE CURED PROPERTIES OF
THESE
MATERIALS OR COULD CREATE A SAFETY HAZARD FOR THEIR NUCLEAR
APPLICATIONS.

THE PRECISE USAGE OF THESE ELASTOMERS WITHIN THE NUCLEAR INDUSTRY
WAS NOT
PROVIDED, BUT APPLICATIONS APPARENTLY INCLUDE FIRE PROTECTION
FUNCTIONS.
THE ELASTOMERS INVOLVED ARE IN THE SYLGARD 170 PRODUCT LINE.  A
RECENT
PART 21 REPORT ON DOW RTV ADHESIVE DEVIATIONS APPEARS TO BE RELATED
TO
THIS PROBLEM (SEE EVENTS #28042 & 28161).

A COPY OF THIS REPORT HAS BEEN SENT TO NRR/TQMB (HAASS).

****UPDATE 01/24/95 1205ET BY ROBERT M. SCHROEDER TAKEN BY
MACKINNON****

PROGRESS SINCE LAST COMMUNICATION ON SILICONE ELASTOMERS ISSUE.


THE FOLLOWING TEXT IS FROM A FACSIMILE RECEIVED DOW CORNING CORP.,
MIDLAND, MI.

"DOW CORNING 96-081 RTV ADHESIVE/SEALANT DOW CORNING HAS COMPLETED
TRIAL
RUNS OF DOW CORNING 96-081 RTV ADHESIVE/SEALANT INCORPORATING THE
HIGHER
PURITY GRADE PIGMENT.  LOT ACCEPTANCE TESTING CONFIRMED THAT THE
MATERIAL
PRODUCED WITH THE HIGHER PURITY GRADE PIGMENT MEETS ALL OF OUR
SALES
SPECIFICATIONS.  THEREFORE, WE ARE ONCE AGAIN CAPABLE OF SUPPLYING
DOW

                        (Continued on next page)


LICENSEE: DOW CORNING CORPORAT          PAGE # 2 OF EVENT NUMBER: 28079

CORNING 96-081 RTV ADHESIVE/SEALANT WHICH MEETS ALL OF OUR SALES
SPECIFICATIONS.  MATERIALS SHOULD BE AVAILABLE MO LATER THAN THE
END OF
FEBRUARY.
UNDERWRITERS LABORATORIES DOW CORNING HAS MET WITH UNDERWRITERS
LABORATORIES AND IDENTIFIED APPROPRIATE FIRE PERFORMANCE TESTS TO
EVALUATE THE SYLGARD 170 SILICONE ELASTOMER, SYLGARD 170 SILICONE
FAST
CURE ELASTOMER, AND DOW CORNING 96-081 RTV ADHESIVE/SEALANT IN
QUESTION. 
TESTING WILL BE COMPLETE IN MID MAY.  A FINAL REPORT DOCUMENTING THE
TEST
RESULTS WILL BE ISSUED BY ISSUED BY THE END OF MAY.
OUR NEXT UPDATE WILL OCCUR NO LATER THAN APRIL 7, 1995 TO PROVIDE A
PROGRESS REPORT ON TESTING.  IF YOU HAVE QUESTIONS, PLEASE CONTACT
ME ON
OUR INFORMATION LINE FOR THIS MATER."

A COPY OF THIS PART 21 UPDATE HAS BEEN FAXED TO WALTER HAASS OF
NRR/TQMB.


*** END OF DOCUMENT ***

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