ON-STATION MONITORING
stations and expeditiously reporting the results.
Monitors do not take time to localize or mark hot spots.
Before the cessation of fallout, all stations that
The team leader shall wear a self-reading pocket
have portable radiac instruments shall monitor and
dosimeter on his outer clothing. Each monitoring team
report gamma intensities at time intervals directed by
shall be given a predetermined route and a safe stay
the damage control assistant. This information is used
time based on the highest estimated topside intensity.
in determining when fallout ceases and in estimating
Large masses of material, such as superstructure,
accumulated doses at these locations. The same
boats, and aircraft, act as shields for gamma radiation
instrument shall be used for all measurements at a
from hot spots and should be used when planning
given location during on-station monitoring. The
routes for protection from hot spots.
instrument shall be held at the same place and in the
same position for each measurement. Beta checks shall
SUPPLEMENTARY SURVEYS
also be conducted during on-station monitoring to
determine if any contamination has infiltrated into the
Supplementary surveys (survey sheet shown in
ship.
table 11-4) are conducted to confirm or revise stay time
calculations. They may also be ordered to localize hot
NOTE
spots for decontamination. Supplementary surveys of
interior spaces shall include beta monitoring to detect
Safe stay-time calculations are not valid
intrusion of contamination. These checks shall be
if they are based on intensity levels measured
scheduled as needed for individual vital stations or
before the fallout stops. The changes in
intensity from that time on are due to
other locations based on the following:
r a d i o a c t ive d e c a y a n d a r e t h e r e f o r e
1. Completion of decontamination or air purge.
predictable.
2. Dosimeter measurements that are at a variance
with predicted doses.
RAPID INTERNAL SURVEY
3. Watch section rotation.
The rapid internal survey shown in table 11-2 is
DETAILED SURVEYS
performed immediately after the cessation of fallout
to get an indication of the severity of the radiation
In a detailed survey, accuracy is more important
hazard at specific locations, primarily action stations.
than speed. Monitors shall proceed slowly and
Safe stay times for interior vital stations can be
carefully. A detailed survey of the entire exterior is
calculated based on the rapid internal survey. These
required before arrival at a repair facility if industrial
locations include vital stations inside the ship and the
closest interior points to topside vital stations. The
decontamination has been ordered. The commanding
locations to be surveyed shall be designated in the
officer may order a detailed survey at any time if the
ship's chemical, biological, and radiological (CBR)
tactical situation permits. He can order a ship-wide
defense bill. They should be precisely identified and
detailed survey or limit it to specific areas in which
marked to ensure uniformity among measurements
relatively high radiation levels have been found. A
taken at different times. Survey routes can be
detailed survey is recommended for any area in which
preprinted using the format provided in and as
measured dosages exceed predicted levels by more
enclosures to the CBR defense bill.
than 25 percent.
RAPID EXTERNAL SURVEY
An example of a detailed survey form is provided
in table 11-5. The grid map method is used to record
The rapid external survey (table 11-3), sometimes
results of this survey. The grid map is formed by
referred to as the gross external survey, is conducted
dividing the ship into grid squares measuring 1 square
after the rapid internal survey to obtain more precise
yard. Each square is surveyed in the center at waist
radiation levels at topside vital stations and at
height. The preparation of detailed survey forms is not
contaminated areas that are irradiating internal vital
required unless the ship is ordered to an industrial
stations. As in the rapid internal survey, the focus is on
getting an accurate measurement quickly at action
facility and a detailed survey is directed.
11-8
