During recent years there has been great concern about
maintaining the utility of our research fleet for the study of natural
isotopes and radioisotopes in the marine environment, while at the
same time trying also to maintain the usefulness of the fleet for
isotopic labeling experiments in which artificial isotopes and radioisotopes
are used. Especially at risk is the use of natural radioisotopic tracers
such as carbon-14 and tritium, where the amounts measured in natural
samples can be as low as 10-12 to 10-15 of the
amounts commonly used in shipboard isotopic labeling experiments,
but there are also problems for natural stable isotope measurements.
Because of this extraordinarily high potential for contamination,
there has been an ongoing effort in the US ocean sciences community
to keep at least a few research vessels of the UNOLS fleet as free
of isotopic contamination as possible.
The policies outlined in this document are intended
as guidelines, the Isotope Usage Committee being well aware that "common
sense" must remain an important component in all shipboard research
decisions. Isotope users are urged to provide as detailed a protocol
as possible for their intended isotope use.
At SIO, R/V Melville and R/V Revelle have
been designated as "clean ships" with respect to isotopic contamination,
and special conditions and restrictions apply to any use of artificial
radioisotopes and stable isotopes on these vessels. Less stringent
conditions and restrictions apply to the other ships of the SIO fleet.
It is important to recognize that the principal objective of the SIO
shipboard isotope usage policy is to establish a practical and enforceable
policy which minimizes the potential for isotopic contamination on
all SIO vessels, while still recognizing and preserving the capabilities
of these vessels with respect to the broad research interests of the
UNOLS community.
Safety concerns are usually not at issue during most
common isotope uses on board ships. Natural levels of radioisotopes
that are subject to contamination are many orders of magnitude lower
than the level which poses risks to human health. Nonetheless any
isotope usage permit will be subject to evaluation by radiation safety
officers from the UCSD Environmental Safety Program, who may express
special concerns about any proposed isotope usage protocol.
We envisage that R/V Melville and R/V Roger
Revelle in particular may be used in the future for natural isotope
tracer studies, (e.g., 14-C, 3-H). For these reasons, all work involving
radioisotopes at concentrations beyond their natural levels, must,
in principle, be carried out in isotope usage vans. This work includes
isotope handling, counting, autoradiography, etc. Areas on deck, where
incubations are carried out, should be monitored for potential spills
on a regular basis (e.g., after heavy use) and regular hosing down
of these areas is strongly encouraged.
It is required that isotope isolation vans have a "clean
bill of health" from the Miami SWAB Group prior to emplacement on
R/V Melville and R/V Roger Revelle. Wearing of special footwear in
the vans (available onboard ship) is mandatory. The vans must, therefore,
have an area in which it is possible to change footwear and clothes
(e.g., foul weather gear). The usefulness of this rule is clear from
a recent event in which an isotope isolation van on R/V Melville was
heavily contaminated but, partially because of the changing of footwear,
this contamination was not spread throughout the ship.
Circumstances may occur in which the above procedures
will place an undue burden upon a scientific party, in that some experiments
may not be feasible within the constraints of the policy, or that,
while feasible, meeting the policy would place an unreasonable logistic
burden upon the program. In such a case a detailed justification will
be required outlining a special protocol indicating a awareness of
the potential effects on contamination outside the working area of
the vans and a proposed monitoring program to detect potential spills.
The Isotope Committee in that case may stipulate conditions associated
with a waiver.
Monitoring of potential radioactive spills is imperative.
For these reasons the following procedures are considered to be of
prime importance. At the end of each leg of R/V Melville and R/V Roger Revelle during which radioisotopes have been used, a SWAB test of
the isotope isolation vans, as well as the deck and laboratory areas
will be carried out by the Miami SWAB test laboratory. If for some
reason (e.g., remoteness or inaccessibility of the ship) the SWAB
operation cannot be carried out by the Miami group, the resident marine
technician, in collaboration with the PI, could be requested to carry
out the SWAB according to Miami instructions. Samples can then be
forwarded to Miami. In case a SWAB test cannot be accomplished, it
will be imperative to lock the vans to access by anyone until the
tests can be performed. This is particularly a necessity because of
clean-up responsibilities of the parties involved in the radioisotopes
usage. If two subsequent legs will have radioisotope usage with different
investigators, then a SWAB test must be carried out between these
legs. The above test program does not preclude the requirement of
regular swab tests by the isotope users, which should be carried out
at least before the start of isotope work, once a week at a minimum
during the cruise, after a suspected spill, and at the end of the
cruise.
Logs must be kept for each isotope van and for the chronology
of isotope usage on R/V Melville and R/V Roger Revelle.
These logs must be kept available in each isotope van.
On other SIO vessels, i.e., R/V R. G. Sproul
and R/V New Horizon, all use and handling of radioisotopes
and stable isotopes will be restricted to assigned isotope vans. In
some special cases, with the permission of the Isotope Usage Panel,
work involving small quantities of isotopes or dilute solutions may
be carried out in the laboratories of these vessels (e.g., scintillation
counting, microautoradiography, chromatographic analysis of labeled
compounds).
Normally, work on the smaller ships requires a multitude
of tasks making changing footwear often too cumbersome. For these
reasons, there will be no rigid requirement for special footwear in
the isotope isolation vans, although such usage is encouraged whenever
possible. With the often tight scheduling of cruises, there may, however,
occur conflicting circumstances. For instance, there may occur usage
of the ship for natural radioisotope occurrences immediately after
the intended isotope usage cruise. In such a case the Isotope Committee
can invoke the footwear ("booties") rule after consultation with the
PI's involved. Timely requests for isotope usage are of importance
at all times, so that scheduling can be done well in advance.
Monitoring as prescribed by the UCSD Radiation Officer
will remain a requirement, but we advocate also the testing of larger
surface areas as suggested by the Miami SWAB group. The Miami SWAB
test is described in RSMAS Technical Report No. TR-84-001, which is
available in each isotope isolation van.
Each investigator has the responsibility to complete
and maintain a monitoring and spill log (available in each van). For
users of stable isotopes no monitoring is possible, but a spill log
is highly recommended.
In order to emphasize the concern of the Isotope Usage
Panel about isotope spills and also to protect SIO from incurring
extensive costs for cleanups, a statement of clean-up responsibility
will be provided on the original isotope usage form and must be signed
prior to the intended cruise. Cleanup cost can be drastically reduced
if the isotope users carry out the bulk of this cleanup work. A breach
of the clean-up commitment will result in a curtailment of the isotope
user's access to SIO vessels. Thus the isotope users assume full liability
for cleanup costs incurred by SIO as a consequence of their work.
For the use of stable isotopes no contamination
tests are possible. This, of course, does not preclude chances of
serious contamination, which may jeopardize work of other investigators.
The isotope user, however, is required to submit a detailed protocol
for the isotope usage envisioned at the time a shiptime request is
made. On the basis of this protocol the Isotope Usage Panel shall
make a recommendation on the particular program in consultation
with the PI.
It is necessary to apply for the use of sealed source
instruments on SIO vessels. Under this item we classify electron capture
gas-chromatographs, as well as other instruments such as the Gamma
Ray Neutron Density instrumentation (GRAPE) for core porosity measurements.
It is necessary to test this equipment for potential leakage prior
to use on the ship. This can be certified by the appropriate Radiation
Officer at the user's home institution.
At the time an official request is made for the use
of a research vessel of the SIO fleet it should be clearly indicated
whether the use of isotopes is envisaged. If so, an information package
will be mailed to the requestor informing him/her of regulations for
isotope usage. A preliminary plan should be submitted at that time
by letter to the Chairman of the Isotope Usage Panel. It is realized
that precise details cannot be made available a few years in advance,
but it is expected that
A "Request for Isotope Usage on SIO Vessels" form must
be filed before the deadlines described below. This request should
be addressed as follows:
Marine Operations Isotope Usage Panel
Ship Scheduling Office, 0210
Scripps Institution of Oceanography
La Jolla, CA 92093
The Ship Scheduling Office will then distribute copies
of the application to the Chairman of the Isotope Usage Panel and
to the UCSD Radiation Safety Officer for review. If this policy is
adhered to, a more uniform treatment of requests will become possible.
For sealed source instruments a letter describing the
instrument and it's intended use should be addressed to the above
address.
(1) R/V Melville and R/V Roger Revelle - at least THREE
months in advance. This allows the Isotope Usage Panel to study the
request and to formulate alternative plans if deemed necessary.
(2) Other SIO vessels: TWO months in advance, unless
much larger scale usage is planned (multiple users, etc.). In the
latter case, the deadline shall be six months prior to the cruise.
(3) Unanticipated, last-minute changes in types, amounts,
and users of isotopes are, on occasion, unavoidable for the success
of the research. The Isotope Usage Panel will countenance such changes
provided they are reasonable and meet with the approval of the Chief
Scientist. All changes must be made by submitting a supplementary
request for approval by the Isotope Usage Panel.
(4) In case of potential scheduling changes it will
be important to communicate immediately with the Isotope Usage Panel,
so that appropriate arrangements can be made.
It should be emphasized that the final responsibility
for the proper usage of isotopes on SIO vessels rests not only with
the isotope users but in particular with the Chief Scientist of each
cruise.
Shipping of Isotopes or Sealed Source Instruments
We urge isotope users to ensure that all shipments of
radioisotopes or of sealed source instruments to and from the ship
are properly certified by the appropriate Radiation Safety Officers.
Revised 7/99
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