BEFORE ENTERING THE RADIATION AREA

. Select the type of radiac that will measure the type of radiation known to be present (use beta/gamma instruments for fission products, and beta/gamma and alpha instruments for weapon incidents/accidents). 

. Select the radiac model that has an indicating range broad enough to measure the radiation intensity of the area to be surveyed. 

l Test the radiac for proper operation. 

l For each survey point, use the lowest range of scaling factor that will give an on-scale reading. 

l Record the exact time of departure (and of return) on the data form.

DURING THE SURVEY . Protect the radiac from contamination. l Be alert for hot spots and note their location. (Don't spend time searching for hot spots unless so directed.)

. Read the radiac to the nearest scale division (these instruments are designed for about 20 percent accuracy). l In detailed monitoring surveys, proceed

slowly and carefully. Thoroughness is more important than speed. For each reading, hold the

radiac steady and allow enough time for the meter to reach maximum deflection. This generally takes no more than 8 to 10 seconds and usually only 3 or 4 seconds.

Topside Gamma Monitoring

This monitoring procedure is a routine action for providing a preattack baseline value of the gamma-radiation level in the vicinity of the open bridge or quarterdeck of a ship. It also provides data to detect the start of transit radiation, to detect the arrival of fallout during the very early time period after burst, to determine the end of fallout and/or base surge, and to determine the approximate effectiveness of whole-ship decontamination operations.

Record readings of open-bridge or quarterdeck gamma intensity routinely. Do this at the beginning of each watch, minimum; every 5 to 10 minutes when fallout is imminent; and every 2 minutes or whenever the radiation level changes by 20 percent (whichever is longer) following fallout. The interval between readings may be increased or decreased by the commanding officer in accordance with the present circumstances. If base-surge contact is presumed possible, monitoring should be performed continuously, noting the peak(s) and the time(s) of the peak(s).

radiacs currently used for this monitoring requirement include the ship-installed AN/PDR65, and the portable AN/PDR-27 and AN/PDR-43.

The data recorded are the ship's location, date, hour, radiation-intensity reading, and radiac used. For example, latitude and longitude, 9 Sept 19XX, 08XX, 0.05 R/hr, AN/PDR-27J, Serial XXX.

Reporting procedures should be established prior to an attack. These procedures should include who is to be notified when the postattack gamma intensity changes by some proportional amount (such as every time the radiation intensity doubles or halves.)

Area Gamma-Exposure Monitoring Survey

Locate dosimeters at monitoring points in deep shelter and at vital topside and below-deck spaces. Readings can then be made to determine the total gamma exposure from the initial, transit, and deposited radiations, as well as routine space checks. The data serves primarily as a rapid check of the exposure levels at various points throughout the ship to identify gamma-radiation-hazard areas for assessing the shipboard radiological situation.

The data will not normally be used to estimate specific doses to personnel. However, if an individual had a malfunctioning dosimeter or none at all, a rough estimate of the individual's dose could be obtained from this survey. Preattack monitoring can be used to identify faulty dosimeters. Exposure readings are also checked routinely at certain stations (such as living spaces) to ensure that low-intensity gamma radiation undetected by other surveys is not a long-term hazard.

Two methods can be considered for area exposure monitoring:

1. The preferred method is to have one set of dosimeters and several spares. Read and record each dosimeter periodically. If a dosimeter shows over 50 percent of full-scale exposure, replace it with a fresh dosimeter.

2. The second choice is to have two sets of dosimeters for each station to be monitored. Place one set on the station and keep the second set in reserve. Collect the exposed dosimeters periodically, and replace them with the freshly charged reserve set. Take the exposed dosimeters to a central location to read and record the exposures.

All self-reading dosimeters (such as the IM-9/PD and the IM-143/PD) can be used for area exposure monitoring. Monitor selected action stations with both a low-reading and a highreading dosimeter.

Rapid Interior Gamma-Monitoring Survey

Conduct a rapid monitoring survey to determine the gamma-radiation levels in shelters and at vital action stations. This survey provides the gamma-intensity readings necessary to make a radiological-situation evaluation and to plan personnel rotation or calculate recommended maximum stay times. When this survey is made before and after a decontamination pass, and the standard intensity results are determined from the survey, the residual number of the decontaminate ion operations can be calculated.

This survey should be completed in about 10 minutes or less. The results should be immediately transmitted to the designated central-control point. This rapid interior gamma-monitoring survey can be combined with an area-exposure monitoring survey to obtain all the radiation data required for the radiological-situation evaluation.

When performing this rapid monitoring

survey, observe the general rules for monitoring. In addition, when reading gamma-radiation intensity, be sure that the beta shield covers the detector if the radiac is so equipped. Hold the radiac at waist height over the designated monitoring point. Make the reading when the indicating needle steadies. Monitoring teams operating earlier than 1 hour after burst should record the time of reading within an accuracy of 1 minute. Monitoring teams operating at times later than 1 hour after burst should record the time of reading within an accuracy of 5 minutes. This procedure applies to all gammaintensity radiacs, such as the AN/PDR-27 and the AN/PDR-43.

Rapid Exterior Gamma-Monitoring Survey

There are three primary purposes for the rapid exterior gamma survey. The first is to obtain data for evaluating the radiological situation at exposed action stations. The second is to locate the general deck areas most in need of decontamination. The third is to determine the effectiveness of a decontamination pass. The personnel on the monitoring teams must be dressed in CBR protective clothing. They should use the designated entrances and exits through the personnel decontamination stations. For their safety, the personnel should wear an IM-143/PD self-reading dosimeter and read it often while conducting the surveys.

Except for the above precautions, the procedure for the exterior survey is the same as that for the interior survey.

This survey technique is also applicable to the radiological recovery of ships at shipyards. However, a shipyard may find it useful to increase the number of monitoring points. Monitoring points spaced 6 feet apart on a square pattern will give excellent resolution of the distribution of radiological contamination. However, this can be too time-consuming except for small ships. The monitoring point spacing can be increased to 12 feet without undue reduction of resolution. On carrier flight decks, a 25-foot spacing is adequate.