ORNL-4191 - the Molten Salt Energy Technologies Web Site

R. B. Gallaher A. N. Smith
The system developed for sampling and analyz-
ing the fuel off-gas was described in the last
progress report. During this report period, in-
stallation of all peripheral equipment was com-
pleted, but the installation of the actual sampling,
mechanism was delayed. (Peripherals include
shielding, external tubing and connection points,
power and instrument wiring, panels, and instru-
ments.)
During final inspection and checkout of the
sainpling mechanism, a failure was detected in a
Monel-to-stainless-steel weld. Further detailed
radiographic inspection revealed some other
welds, mostly Monel to stainless steel, that were
judged to be marginal or unacceptable for primary
reactor containment. Therefore, the mechanism
was modified to eliminate man.y of the dissirnilar-
metal welds (by substituting stainless steel valves
for Monel in the valve manifold) and to reduce
mechanical stresses at the welds. The valve
substitution eliminated brazed joints at the valve
bodies, and other minor modifications were made
to improve the containment integrity of the assembly
and the sample transport bottle. 'The sampler was
reassembled, with all welds ful.ly certified, but
installation was deferred because of other work
during the shutdown following run 12.
2.2 REMOTE MAINTENANCE
Robert Blimberg
During this report period the trend for more re-
mote rnairitenance to be handled routinely was ac-
'MSR Program Semiann. Progr. Hept. Feb. 28, 1967,
OKNL-4 119, pp. 41-42.
Dunlap Scott
36
celerat.ed, hut development efforts remained considerable
and varied.
The shutdown in May and June was planned, and
considerable effort was spent in advance on development
of procedures, preparation of tools and
equipment, and training of maintenance personnel.
As a result, most of the remote maintenance work
during this shutdown was handled by the normal
maintenance forces. Development personnel also
participated and afterward reevaluated procedures
and tools. The next shutdown was unscheduled.
Although some equipment and general techniques
already developed for other jobs proved to be
adaptable, intensive work was required to develop
tools and procedures for retrieving the sample
1 at c h.
Preparations for Shutdown After Run 11
At the beginning of MSKE operation, when tools
and procedures for all remote maintenance jobs
were still being tested and revised, development
personnel provided direct guidance and much of
the actual work. Rut the work planned for the
shutdown after run 11 consisted mainly of jobs for
which tools and procedures had already been
proved. Therefore, the contribution of the developnent
group shifted more toward training maintenance
personnel, helping plan the operations,
and putting +.he maintenance equipment in readiness.
The training program consisted of a series of
lectures ~ demonstrations, and practice sessions
conducted by members of the maintenance development
group and attended by some 30 people, including
5 craft skills and their supervision. 'The
lectures covered health physics, safety considerations,
general requirements of all remote maintenance,
remote maintenance strategy used at the