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How to conduct
and document monthly surveys on NIH 88-12
| Form NIH
88-12 |
| 1. |
Determine
how many modules are included in your lab |
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Generally, an aisle
is considered a module. However, check your authorized user's
monthly status report and/or contractor surveys. The number
of surveys they perform in your area is the number of modules
you officially have. If your lab(s) are newly activated
and/or you cannot determine the number of modules you have,
contact your Area Health Physicist
at 301-496-5774. |
| 2. |
For each
module, determine if isotopes were used since the last monthly
survey |
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"Use" is
defined as aliquoting directly from a source vial; also
diluting or otherwise manipulating gels, plates, petri dishes,
waste, or samples that were labeled previously with radionuclides.
"No-use" means isotopes in an enclosed container that was
not opened, but rather stored or transported via double
containment to another location for manipulation or work. |
| 3. |
Once
the question of usage has been resolved |
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For modules where
usage did not occur since the last survey, no smear survey
is required. However, DRS still requires that a survey documenting
this fact be submitted to the DRS. (See
step 9 for documenting multiple module surveys) |
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For modules where
usage occurred, a smear survey is required. A meter survey
is optional, if the isotope is detectable, but not required.
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| 4. |
Performing
a smear survey: |
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- The smears (available
in NIH stores) should be filter paper that will become
transparent or dissolve in scintillation fluid.
- A minimum of 10 smears should
be taken per module, including at least two
on the floor.
- Other recommended areas to smear are
sinks, benches where radioisotope work was performed,
near waste containers, fridge handles, and storage locations.
The idea is to survey the areas that are most likely
to be contaminated.
- Apply moderate pressure to the surface
of interest when smearing. A good technique to use is
to wipe in an 'S' motion over a general area.
- The area should be large enough that
contamination won't be overlooked, but reason should
be applied. If a smear taken over a widespread area
is contaminated, it may be cumbersome to figure out
what area is actually contaminated.
- Also, it is possible to spread contamination
by smearing multiple areas with a single smear.
- Remember that the results are in units
of 100 cm².
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| 5. |
Preparation
and counting of smears: |
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- Prepare the
smears for counting by adding scintillation fluid (or
place in empty vial for gamma count). It may be necessary
to dark-adapt samples to prevent erroneous chemoluminescence
readings.
- Be sure to use a liquid scintillation
counter (LSC) for pure beta emitters (e.g. H-3, C-14,
P-32, P-33, Cl-36, Ca-45, Fe-55, Ni-63, Cu-64, Sr-90,
and Y-90). A gamma counter may be used for any isotope
that has a gamma component (e.g. Na-22, Cr-51, Se-75,
Rb-86, I-125, or I-131), but an LSC is acceptable for
all isotopes.
- It is important to make sure the counting
equipment chosen is working properly and set up to count
the isotopes in question. Counting protocols are sometimes
found altered by unknown persons or power failures.
Be sure to check what isotopes the counter protocol
is set up to look for. A survey that is submitted with
windows that don't cover the isotope of interest will
be returned for recount. Check with the manufacturer's
instructions to set up windows correctly. It is permissible
to count samples on the "wide" channel (i.e. counting
the entire spectrum of energies).
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| 6. |
Producing
technically defensible results: |
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- DRS recommends
that a background smear (i.e. not rubbed on any surface)
be added to the set of samples, which helps ensure that
you haven't cross-contaminated samples or contaminated
the internals of the counter. Also, in some cases, the
background reading can indicate a counter problem.
- DRS also recommends that smears be
counted for at least 1 minute, to provide adequate counting
statistics. If your counter is programmed to move to
the next sample due to insufficient counts after a preset
time, that is acceptable.
- It is also a good idea to run a set
of known standards that approximate the energies of
the isotopes of interest. This will tell you how well
the counter is seeing what it is supposed to see.
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| 7. |
Once counting
is complete, it is necessary to review the results on the
printout. The following list outlines what should be checked: |
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- Verify the count
time was preset for 1 minute.
- Verify the correct
date is displayed. If after consulting manufacturer
it is impossible to display date, contact the DRS for
instructions.
- Verify the printout
displays the count rates in the windows that
are appropriate for the isotopes of interest.
- Check the background
smear result. Is it reasonable? Is it similar to past
levels? An increasing background over time can indicate
internal contamination, external radiation sources,
or counter problems. A background that is chronically
high means the loss of ability to detect lower levels
of contamination (important consideration when clearing
labs or surveying unrestricted areas)
- Check the other
results. If there are elevated counts, there may be
contamination. Be sure you understand whether your printed
results are in CPM or DPM, and whether
background is subtracted by the counter. If your printout
shows elevated levels in the low channel for multiple
samples, you may have a chemoluminescence problem. Some
counters display a "lumex %." The higher this number
is, the more likely elevated counts is due to chemoluminescence.
You should dark adapt the samples and recount. Note
that this condition is not usually seen in middle or
high energy ranges. If you submit a survey full of high
numbers with no explanation or resolution, the DRS will
ask for one.
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| 8. |
If you
have count rates above background: |
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- The NRC has
a policy that exposures to nuclides be kept As
Low As Reasonably Achievable
(ALARA). This is a condition of our license to
possess and use radioactive materials. While the limit
for removable contamination inside a posted (restricted)
area is 2200 dpm/100 cm² (220 dpm/100 cm² for alpha
emitters) above background, ALARA dictates that
any detectable loose surface contamination be cleaned
up. Your Area Health Physicist may visit your lab, even
if the contamination is below the limit, if it is widespread
or in conspicuous places (e.g. floor, sinks, objects
that shouldn't be contaminated), and no action appears
to have been taken by the lab upon discovery.
- If you determine through recount, resmear,
or low lumex % that an elevated count is actual contamination,
steps must be immediately taken to determine
the extent of the contamination and initiate clean up
actions (decon).
- Using soap and water, lift away, count-off,
or other decontaminating agent, wipe up the spot that
was identified on the printout. If the smear you had
taken was over several items (e.g. one smear taken over
three different desks), it may be necessary to first
take separate smears to narrow down where the contamination
actually lies. Note: It is possible to have decontaminated
a surface with the original smear, so you might not
find it again. If this occurs you should still perform
the next step.
- After decontaminating the known contaminated
spot, re-smear the spot, and take additional smears
in the vicinity of the known contaminated area. While
it may be helpful to use a meter to identify additional
areas of contamination, radiac meters are not sensitive
enough to confidently say low-level contamination is
present, even for P-32.
DO NOT USE A METER TO DECIDE WHEN TO STOP CLEANUP
ACTIVITY!
Be sure to smear a surrounding area large enough
to account for such things as tracking via shoes, or
liquid dripping from an above surface or onto something
below.
- If it appears that contamination is
outside the restricted areas (i.e. hallway, internal
offices, non-posted modules that are internally connected)
or that the contamination is spread out over 10 ft²
(not necessarily continuous), then by license condition
the DRS must be notified immediately.
- If you are having trouble reaching
a conclusion on any contamination event you are
encouraged to call your Area Health
Physicist for assistance.
- After counting (and decon, if necessary),
you are required to document your findings and submit
them to the DRS:
- The necessary form is the NIH
88-12 rev. 10/99, which is only available on the
web at this time . This form should be completely filled
out to avoid having it returned for correction. It
is also necessary to submit a copy of the LSC or gamma
counter printout. The current date must appear on
the printout. Refer to the manufacturer's instructions
to set the correct date on your counter, and contact
the DRS for instructions if it is impossible to have
the date on the printout.
- Multiple
modules may be represented on one survey form. It is
very helpful to the DRS if multiple module surveys are
submitted the same way each month. This will prevent
modules from receiving no credit for submittal when
surveys were, in fact, submitted. If some modules had
isotope usage and some didn't, clearly indicate on
the sketch which modules had no use, so that your
survey will not be returned for insufficient smears.
- The results must be individually
stated in DPM. General results such as "<100",
"<2200", "<BKG", and "BKG"
are all unacceptable. If your counter does not
compute DPM for you, you must compute it yourself:
DPM=CPM ÷ efficiency of counter for that isotope. If
you do not know the efficiency of your counter, consult
the manufacturer's instructions. If you need standards
to determine efficiency, you may use another user's
standards or contact the DRS
for assistance.
- One copy of the survey and printout
will be submitted to the DRS. Another copy must be maintained
by the lab for a minimum of three years. If the
lab is to be disbanded and/or otherwise unused for a
long period, contact the DRS concerning the disposition
of records.
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| 9. |
Survey
Form returns |
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- The following
common errors/omissions (not all-inclusive) will cause
your survey to be returned to you for correction. Please
note that credit is not given for a returned survey
until it is resubmitted to the DRS and accepted by a
reviewer. Items marked with an*not required
if entire survey is a "no nuclides used" survey.
- no signature
- no date
(date should be when the smears were actually
taken)
- missing
sketch of lab
- smear locations
not identified
- nuclides
used section not completed, if "no nuclides used"
box is also not checked
- surveyor
has not either been given orientation by Authorized
Used (with documentation submitted to DRS) or attended
the Radiation Safety in the Laboratory course
- results
are not individually listed, in DPM (unless printout
converts to DPM automatically)
- insufficient
number of smears per module
- insufficient
floor smears per module
- survey is
post-dated or inconsistent with the printout date
- LSC or GC
number (from label on counter) is not indicated
on the form
- If the Authorized
User listed on the survey does not match what we
have in our database, we may send the survey (or
copy) back for clarification. While labs can have
their owners changed at the discretion of the involved
AU's, it is necessary to inform us when this occurs,
so that status reports will be correct, and the
right individual will be involved if an unusual
event occurs. If the DRS sends back a survey for
this, please contact the DRS and provide the up-to-date
status of the lab in question.
- If a survey
is returned to your lab (always sent to the Authorized
User for the lab), make the necessary corrections on
both our copy, as well as the copy you filed in your
records. Return the corrected copy to the DRS. Due to
the large number of returns (200-300 per month), we
cannot send reminders that these surveys have yet to
be resubmitted to us. However, if sufficient time has
passed (10-20 business days), and the surveys have not
been resubmitted to us, we may deem them missing and
subject to enforcement action.
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| 10. |
When you're
finished: |
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When you have completed
the survey form and attached the results printout, send
it via campus mail to 21/116 or FAX it to 301-496-3544.
If you wish to verify that a FAX has been received, wait
3 business days for it to be processed, and then call 301-496-5774
and ask for the survey reviewer. |
| 11. |
What
to do if a survey is missed: |
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- If you discover
(or are informed) that a monthly survey has been missed,
there is no reason to panic (unless you are in the habit
of missing them all the time). Isolated instances will
not warrant enforcement action against an Authorized
User.
- First, contact your Area Health
Physicist and inform DRS that the survey was not
performed.
- Next, if isotopes were used during
any of the missing month(s), immediately
perform a smear survey for the current month, which
will demonstrate that contamination does not exist in
your lab.
- DO NOT, UNDER ANY CIRCUMSTANCES,
COMPLETE A SURVEY FORM (DATED IN THE PAST) THAT SHOWS
SMEARS WERE TAKEN, UNLESS YOU HAVE AN ORIGINAL PRINTOUT
THAT SHOWS THE ORIGINAL DATE. DOING SO CONSTITUTES FALSIFICATION
OF NRC-REQUIRED DOCUMENTS, WHICH CARRIES SEVERE
CONSEQUENCES FOR VIOLATORS!
- For missing months where isotopes were
not used, fill out a survey form with the current
date and a comment in the remarks field "isotopes were
not used in this lab during MM/YY".
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| 12. |
What DRS
does with the surveys it receives: |
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- Every survey
is thoroughly reviewed by a health physicist. The reviewer
checks all the items in #10 above, and reviews all aspects
of the printout.
- Surveys that have errors or omissions
are returned to the Authorized User for correction.
The survey will be accompanied by a form letter that
indicates what needs correcting. If you have a question
concerning items DRS has cited, please call 301-496-5774
and ask for the survey reviewer.
- Surveys that are clerically correct,
but have other anomalies such as contamination or usage
in an inactive lab, are forwarded to the appropriate
Area Health Physicist for follow-up. Surveys that are
completely accepted by the DRS are maintained in our
files. Keep in mind that this does not alleviate
the requirement for the labs to maintain their records
for at least three years.
- The DRS reviews survey compliance for
labs on a rotating schedule so that each lab is reviewed
approximately every 8-12 weeks.
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