Chapter 6 Personnel contamination monitoring is a crucial aspect of safety in various industries, including nuclear power plants, research facilities, and healthcare settings. It involves the measurement and assessment of potential contamination of workers or personnel with radioactive materials, hazardous chemicals, or other harmful substances. The primary goals of personnel contamination monitoring are to protect workers from exposure to harmful substances and to ensure compliance with safety regulations. Here are some key aspects of personnel contamination monitoring:
Types of Contaminants: Personnel may be exposed to various types of contaminants, including radioactive materials, toxic chemicals, biological agents, or hazardous materials. The specific monitoring methods and equipment used depend on the nature of the contaminants.
Monitoring Devices: Various monitoring devices and instruments are used to detect and measure contamination. These devices can include:
Radiation Detectors: These instruments measure the levels of ionizing radiation, such as alpha, beta, gamma, and neutron radiation.
Chemical Sensors: These sensors can detect the presence of specific chemicals or hazardous substances in the environment or on personnel.
Biological Monitoring: This involves assessing the exposure to biological agents, such as bacteria or viruses, through methods like blood tests or swab sampling.
Dosimetry: Dosimeters are worn by personnel to measure their exposure to ionizing radiation over time. They can be in the form of film badges, thermoluminescent dosimeters (TLDs), or electronic personal dosimeters (EPDs). These devices record cumulative exposure and provide information for radiation safety assessments.
Contamination Assessment: Contamination can occur on the skin, clothing, or inside the body (inhalation or ingestion). Monitoring methods may include swabbing, wipe tests, direct skin monitoring, and excreta analysis to determine the extent and type of contamination.
Decontamination: If contamination is detected, decontamination procedures are implemented to remove or reduce the contamination from personnel and their belongings. Decontamination processes may involve washing, scrubbing, or specialized equipment.
Regulatory Compliance: Personnel contamination monitoring is often mandated by regulatory authorities in industries where exposure to hazardous materials is a concern. Compliance with regulations is essential to maintaining a safe working environment and avoiding legal and health-related issues.
Training and Education: Personnel working in environments with potential contamination risks should receive proper training on contamination monitoring procedures, the use of monitoring equipment, and safety protocols. Education and awareness are essential to preventing contamination and ensuring prompt response when it occurs.
Record Keeping: Comprehensive records of personnel monitoring, including exposure levels, dosimetry results, and decontamination activities, must be maintained to track individual and collective radiation or contamination exposures.
Emergency Response: Facilities should have emergency response plans in place in case of accidents or incidents involving contamination. This includes procedures for evacuating contaminated areas and providing medical treatment as needed.
Continuous Improvement: Ongoing evaluation and improvement of contamination monitoring procedures and equipment are essential to adapt to changing risks and technologies.
Personnel contamination monitoring is a critical element of occupational safety in industries where exposure to hazardous materials is a concern. It helps protect workers, the public, and the environment by ensuring that exposure levels are minimized and controlled.
Lesson:
This procedure describes the process for monitoring
personnel for skin and clothing contamination and proper decontamination
methods.
This procedure describes the
normal process for monitoring personnel assuming contamination monitors are
operational. In the event equipment is
not available site specific procedures will provide guidance to supplemental personnel. Documentation of personnel contamination
events will be completed using site specific forms, electronic processes, or
the attachments to this procedure.
Member utilities are expected to use
this standard to enable supplemental workers to transition between nuclear
power plants with minimal site-specific training. Compliance with these
instructions is expected without additional site requirements or process
deviations being imposed that may require additional training or challenge the
performance of supplemental workers.
This is an information use
procedure that will be used to train and instruct supplemental radiological
protection technicians. Member utilities
may implement these process requirements in site procedures provided the site
procedures are equivalent and updated whenever this Nuclear Industry Standard
Process (NISP) is revised. Member
utilities may also elect to delete equivalent site-specific procedures and use
this procedure for training and instruction.
Current revisions are maintained on the INPO website.
Terms, acronyms, and
definitions are provided in NISP-RP-013, Radiological
Protection Glossary.
Clarifying notes for requirements and process steps
are provided in Section 4.0 using superscript numbers in the preceding
sections.
2.1
All personnel must exit through a beta and gamma
sensitive monitor(s) prior to final exit from the RCA. Contamination monitoring
may also occur inside the plant in locations where the background is suitable
for monitoring.
2.2
Personnel Contamination Events are classified
using the following criteria: 7
2.2.1
Level 1 100
ccpm – 5000 ccpm
2.2.2
Level 2 >5000
ccpm – 50,000 ccpm
2.2.3
Level 3 >50,000
ccpm
2.3
Skin dose assessment will be determined by the
sites prospective determination or as
defined in section 3.4.5. 12
2.3.1
If there is no prospective determination that documents
that individuals are not likely to receive in excess of 10 percent of the
limits, recording and reporting is required under NRC regulations
2.3.2
If the site has a documented prospective
determination documenting that individuals are not likely to receive in excess
of 10 percent of the limits, recording and reporting of identified
contamination is voluntary, unless the exposure actually exceeds 5000 mrem in
the calendar year.
2.4
Use Attachment 3, PCE Classification Guideline, to
determine if the cause of the alarm should be classified as a PCE.
2.5
Alarm set points will be established by the site
based on background, instrument efficiency, and hard to detect radionuclides
and should alarm when 5000 dpm of radioactivity has been detected.
2.6
Sensitivity to the individual’s gender must be
taken into consideration prior to survey and any decontamination actions.
2.7
If an alarm occurs on a contamination monitor
then take the following actions:
2.7.1
Note the location of the alarm and the activity.
2.7.2
Instruct the individual to re-monitor.
2.7.3
If no alarm occurs, the individual may exit or
proceed to the final exit point for monitoring
2.7.4
If second alarm occurs note the location and activity
and proceed to step 2.8
2.8
In the event of a second alarm, indicating a
potential contamination event, immediately take the following actions:
2.8.1
Take actions to prevent the spread of
contamination in the surrounding area and to other personnel.
2.8.2
In a background area of 200 cpm or less, using a
frisker1 or equivalent instrument, and maintaining a detector to
surface distance of approximately ½ inch or less, slowly survey the individual
with additional focus on suspected areas to determine the location and activity
of contamination.
2.8.3
Ensure areas are surveyed which could have been partially
shielded from the detectors such as arm pits, folds in clothing, or tops of
shoes.
2.8.4
Individuals can be contaminated in more than one
location or by more than one radiological concern. Ensure the individual is thoroughly surveyed.
2
2.8.5
If the individual was working in an area posted
and controlled for alpha contamination then perform a survey using an
instrument capable of detecting alpha contamination. If alpha contamination is detected notify RP
Supervision. 3
2.9
If the survey indicates the presence of discrete
radioactive particles then capture and remove particles. 8
2.9.1
Using proper contamination controls capture the
particle.
2.9.2
Note the location of the particle (skin or
clothing).
2.9.3
Document the survey results of the particle
using a frisker, or if necessary, an open window ion chamber reading.
2.9.4
If particle was found on clothing, survey and
document the reading obtained on top and underneath the clothing (i.e. area in
contact with skin). 9
2.9.5
Secure the particle in the proper container and
label as radioactive material. 4
2.9.6
Send the discrete particle for isotopic
analysis.
2.10 If
the survey indicates facial contamination inside the area normally protected by
the sealing surface of a respirator, then the potential for internal
contamination exists. Shower the
individual as appropriate and perform an in-vivo assessment.
2.11 If
the survey indicates beta/gamma contamination on clothing then take the
following actions:
2.11.1 Remove
the clothing using proper contamination controls to prevent the spread of
contamination to other parts of the body or the surrounding area.
2.11.2 Survey
the area where the clothing was removed with a frisker. If there are no indications of contamination
instruct the individual to re-monitor in beta and gamma exit monitors.
2.11.3 Prior
to the decontamination or disposal of the contaminated clothing ensure all
survey data, or isotopic analysis, has been obtained to support skin dose
assessments. 9
2.12 If
the survey indicates contamination on
the skin, other than the facial area, then take the following actions:
2.12.1 Decontaminate
the skin using one of the methods listed in section 3.3.
2.12.2 Survey
the area and ensure the contamination has been removed. If contamination is still indicated repeat
the decontamination process up to three times.
If contamination is still indicated contact RP Supervision. 6
2.12.3 If
survey indicates contamination has been removed instruct the individual to
re-monitor in beta and gamma exit monitors.
2.13 If
survey indicates the contamination is from naturally occurring isotopes or noble
gas then take the following actions:
2.13.1 Instruct
the individual to remain in the area to allow for decay, and re-monitor after approximately
30 minutes.
2.13.2 If
preferred, the individual can replace the clothing suspected to be contaminated
with naturally occurring isotopes or noble gas and re-monitor. If no alarm occurs the individual can exit
the area.
2.13.3 If
counts have not decreased after 30 minutes then the activity may not be from
natural products or noble gas. Re-survey
for other causes of contamination alarms.
2.13.4 Section
3.2.5 provides additional guidance for release of personnel with suspected
naturally occurring isotopes or noble gas contamination.
2.14 Contamination
events can often involve multiple personnel.
Take the following actions as appropriate to maintain contamination
control. Actions can be taken in any
order.
2.14.1 If
multiple personnel indicate signs of contamination contact RP Supervision for
additional assistance.
2.14.2 Maintain
contamination control by keeping those individuals suspected of contamination
segregated in one area. Provide
instructions to individuals on where they should be located and why.
2.14.3 If
the event involves foot contaminations provide protective shoe covers or mats
to prevent the spread of contamination to clean areas while individuals are
being processed.
2.14.4 Maintain
the clean area clean by performing frequent surveys of the area.
2.14.5 As
quickly as possible, determine the cause of the event and the route taken to
the monitoring location so additional contamination surveys can be performed in
the appropriate locations to prevent additional contamination events.
2.14.6 If
the individuals indicate potential internal contamination, alert RP Supervision
so air samples can be obtained from the work area.
2.15 Follow
up actions for personnel contamination events.
2.15.1 Notify
RP Supervision when a personnel contamination event occurs.
2.15.2 Gather
as much information as possible from the individual(s) involved to help
determine the cause of the event and provide this information to RP
Supervision. Questions to consider are
listed below:
a. Was
there a failure of protective clothing?
b. Has
a leak or spill occurred?
c. Was
there a failure of HEPA ventilation / Vacuum equipment in the area?
d. Was
there grinding, burning, or flapping on potentially contaminated surfaces?
e. Has
there been a change in work scope or work process such as implementation of a
different tool or opening of a different component?
f.
Is there a reason to suspect the contamination
levels at the work site may have changed?
g. Has
the environmental conditions (increase in temperature) at the work site
changed?
2.15.3 Follow
up surveys should be taken in the work area to ensure contamination hazards
have not changed, as applicable.
2.15.4 If
the event involves shoe contaminations then surveys should be taken from the
work location to the monitoring location to ensure a spread of contamination
has not taken place.
2.15.5 Once
all of the data has been gathered document the event in accordance section
3.4. If documented on Attachment 1,
Personnel Contamination Event, determine the cause code using the following
codes (required for level 2 and 3 PCEs only):
a. R1
– Clean area: Contamination occurred
outside of a posted contamination area.
b. R2
– Poor work practice: Contamination
occurred due to, for example, worker not dressed out properly, not following
RWP instruction, not undressing properly, or touching exposed skin
inappropriately.
c. R3
– Inadequate rad controls: Contamination
caused by, for example, a failure to prescribe adequate protective clothing,
inadequate decontamination or control of contamination, or an unnoticed change
in radiological conditions.
d. R4-
Equipment failure or spill related:
Contamination occurred due to equipment failure (such as valve leak) or
an spill (such as improper valve manipulation)
e. R5
– Protective clothing: Contamination
caused by defect of the protective clothing such as a tear, or caused by
existing contamination of the protective clothing. This code may also be used when it is
determined that “wicking” or “sweat through” of the PCs has occurred while in
the respective work area.
3.0
Process
1.1
Respond to second contamination monitor alarm 1.1.1 Perform
a survey using a frisker1 of the locations indicated by the exit
monitor. 1.1.2 Personnel
with 100 ccpm or greater are considered contaminated and actions must be taken
to remove the contamination before they are released, or in the case of
internal contamination, the dose assessment process has been started. 1.1.3 Notify
RP Supervision of exit monitor alarms so actions can be taken to prevent
additional contamination events from occurring. 1.1.4 Once
an individual has alarmed an exit monitor they must clear the same type of
monitor before being released. 1.1.5 It
is essential that communications be effective between the RP Technician and the
worker when responding to a contamination alarm. Use Attachment 2, Communication Guidelines,
for methods to ensure communications are effective. 1.1.6 Take
the following actions when responding to a contamination monitor alarm at the
exit to the protected area. a. Validate
the alarm by asking the individual to re-monitor. If no alarm occurs the individual may be
released. 10 If alarm occurs note the location of the alarm and
perform a survey using a frisker or equivalent instrument of the individual
with additional focus on the alarm zone. b. If
contamination is detected then determine the following: a.
Has the individual recently received medical
testing involving radionuclides? b.
Is the alarm caused by naturally occurring
radioactive material such as tungsten welding rods? c.
If the contamination is not from medical or
naturally occurring radionuclides then control the affected area to prevent a
spread of contamination during transport of the individual. This
could include wrapping the affected areas, or if contamination is on the shoe, removing
the item and placing in a bag. d.
Notify RP Supervision of survey results and
request assistance if necessary. c. Transport
the individual to the normal RCA exit point and complete additional surveys and
decontamination as necessary. d. Survey
the exit area and travel path of the individual to ensure no contamination
spread occurred during the event.
Document all surveys. 1.2
Determine contamination hazard 1.2.1 Discrete
particles a. High
count rate in a small localized area can be an indication of a discrete
particle. 1.2.2 Internal
contamination a. Approximate
equal counts on front of chest and back can be an indication of internal
contamination. b. Facial
contamination inside the area normally protected by the sealing surface of a
respirator. c. The
inability to pass a gamma monitor, when alarms occur in the upper region of the
body, can be an indication of internal contamination. d. If
radioactivity is detected around the nose, request an individual to blow their
nose on a tissue. Treat the item as
potentially contaminated and analyze for presence of contamination. Any indications of radioactive material would
suggest the possibility of internal contamination. Perform a whole body count and completed
dose assessment if required. 1.2.3 Contamination
on skin a. Evaluate
the need for a skin dose assessment based on the criteria in 3.4.4. b. If
contamination is in or around an open wound notify RP Supervision and treat as
an internal contamination event and ensure a dose assessment is completed.
11 1.2.4 Contamination
on clothing a. Folds
or layers of clothing can act as a shield.
Ensure all areas are thoroughly surveyed. 1.2.5 Noble
gas or naturally occurring radioactivity a. Low
level counts evenly spread over a wide area can be an indication of noble gas
or naturally occurring radioactive material. b. Clothing
(i.e. polyester) capable of carrying a relatively high electrostatic charge
typically in high friction areas such as the knee and elbow. c. If
the affected zone is 300 ccpm or less when monitored with a Geiger-Muller type
frisker, and the net beta count to net alpha count ratio is between 0.4 and
5.0, then consider the contamination to be radon decay products. d. Naturally
occurring radioactive material have a half-life less than 30 minutes. Allow for time to decay and re-monitor. If counts are decreasing it can be an
indication of noble gas or naturally occurring radioactivity. e. Individuals
can be conditionally released with radon or noble gas under the following
conditions a.
RPM/Designee has approved the conditional
release b.
Radon or noble gas has been confirmed to be the
cause of the alarm by step 3.2.5.C. above, or individual has exited from
confirmed noble gas or radon area. c.
Individual was not working in a posted
contaminated area. d.
Individual is instructed to re-monitor prior to
exit from the site. 1.3
Personnel Decontamination 1.3.1 If
an injury has occurred the medical needs take precedence over the
decontamination process. 1.3.2 Only
ANSI qualified RP Technicians can perform or direct decontamination activities
on personnel. 1.3.3 Medical
assistance is required for decontamination of wounds or around the eyes or for
decontamination methods other than those listed in this procedure. 1.3.4 The
gender of the individual and privacy should be taken into consideration during
the decontamination process. 1.3.5 Effective
communications is essential between the RP Technician and the worker during the
decontamination process. Use Attachment
2, Communication Guidelines, to ensure effective communications. 1.3.6 Proper
contamination controls must be used by the RP technician while performing or
assisting in personnel decontamination.
As a minimum this includes wearing protective gloves. 1.3.7 To
decontaminate a discrete particle on clothing, capture with masking or duct
tape. 1.3.8 To
decontaminate a discrete particle on skin, capture with Wet One wipe or similar
material. 1.3.9 To
decontaminate skin use mild soap and tepid water. Observe the skin during the decontamination
process and stop if redness of the skin occurs. Three attempts can be made
using soap and water. Contact RP
Supervision for additional instructions after three attempts, or redness of the
skin occurs. 1.3.10 RP
Supervision/RP Management is required to approve decontamination methods other
than those described in steps 3.3.7 through 3.3.9. Consider obtaining medical
assistance for aggressive decontamination methods or contamination that needs
to be surgically removed. 1.3.11 Contaminated
clothing shall be removed taking care not to spread contamination. The area of skin beneath the clothing shall
be surveyed to ensure no additional contamination is indicated. 1.3.12 Clothing
identified as contaminated, cannot be returned unless it has been
decontaminated and worn through the contamination monitors by the individual. a. If
decontamination is completed later, and the individual is not available, then
the clothing can be released based on requirements in NISP-RP-07, Control ofRadioactive Material. 1.3.13 If
natural occurring radioactive material or noble gas is suspected individuals
can be decontaminated by allowing for radioactive decay. 1.3.14 To
be released individuals must successfully pass beta/gamma personnel monitors
without alarming. In some cases, such as
internal contaminations or incomplete decontamination, individuals may cause an
alarm but can only be released with the approval of the RPM. 1.4
Dose assessment and documentation 1.4.1 Personnel
Contamination Events can be documented using attachments in this procedure, equivalent
site forms, or electronic processes. Use
attachment 3, PCE Classification Guidelines, to help determine if the event
should be documented as a PCE. 1.4.2 All
personnel contamination events are documented on Attachment 4, Personnel
Contamination Event Log. 1.4.3 Personnel
contamination events (PCEs) are documented on Attachment 1, Personnel
Contamination Event, for Level 2 and 3 events. 1.4.4 Documentation
is not required for events involving noble gas, medical radioisotopes,
naturally occurring radioactive material, or contamination <100 ccpm. 1.4.5 Dose
assessment is required for any of the following: 12 a. Suspected
internal contamination. 13 b. Contaminated
wound c. Discrete
particle exposure of >50,000 ccpm. d. Skin
contamination of >50,000 ccpm. e. Contamination
on skin is ≥250,000 ccpm-hours (count
rate (ccpm) X time (in hours) 3.1
EPRI
Technical Report 3002009426, Guidelines for Industry Response to Personnel
Contaminations, Rev 1.1 December 2016 3.2
EPRI
Alpha Monitoring and Control Guidelines for Operating Nuclear Power Stations,
Revision 2, August 2013. 3.3
NISP-RP-013, Radiological Protection Glossary 3.4
NISP-RP-07, Control of Radioactive Material
Attachment 1: Personnel
Contamination Event - Sample
Action Level – circle the appropriate level – (Action Level 2 is > 5,000 ccpm - 50,000
ccpm),(Action Level 3 is > 50,000 ccpm). Section 1 – Event
General Information Name of Individual: ______________________
ID #: ____________ Time/Date of Detection: _________/_________
Estimated Exposure Time: _______________ hours RWP and Task #: ________________ Individual’s Department or Company:
_____________________ Unit/Building/Elevation/Room/etc: _________________________________________________________ Survey Instruments (ID# / IF above Instrument used for Skin
Dose Assessment, verify current source checked, Initial/date__________/_______ Brief Description of
Incident:_______________________________________________________________________ ______________________________________________________________________________________________ Section 2 –
Clothing/Shoes Item
Contaminated: Original
Activity *Type
of Contamination ___________________________ ________________ccpm
1
2
___________________________ ________________ccpm
1
2 ___________________________ ________________ccpm
1
2
* Type of
contamination – check appropriate Disposition of Clothing: Decontaminated Disposal
Other (Specify) ________________
Attachment 1: Personnel Contamination Event – Sample
(continued) Section 3 – Skin
Decontamination Outcome: Successful Contamination Remains (Specify
Location/Level): ______________________________________ Decontamination method
_______________________________________________________________________________ Decontamination Completed:
Date: ______________ Time: ____________ RP Initials and ID #: _______/_____________ The decontamination process was
explained to me and I have been given an opportunity to have any
questions/concerns about this event answered to my satisfaction. Individual Print/Sign:_____________/______________ Date:__________ Phone (ext):_______ Section 4 – Cause Codes Select the most appropriate cause code based on data from the
event from the table below. R1 Clean Area R2 Poor Work Practices R3 Inadequate Rad Controls R4 Equipment Failure or event R5 Protective Clothing Failure Section 5 – Additional information _______________________________________________________________________________________________________________________________________________________________________________________________________________________________ PCE Record
Completed By Print/Sign:
________________________/____________________________ Date: ________________ Reviewed By
Print/Sign
_____________________________________/_____________________________ Date:
________________ Attachment 2: Communication Guidelines
1.
Avoid using slang terms which can cause
confusion or anxiety with the worker such as “crapped up” or “you’re hot”. 2.
Take into consideration the gender of the
individual. Typically the same gender
will support the surveying requirements for a contamination monitor alarm. 3.
Explain your actions before you take them. Help the worker understand the reason for the
action. 4.
Be sensitive to the workers concerns. This may be the first time they have
experience a contamination monitor going into alarm and may have true
anxiety. Explain the low level detection
ability of the unit. If needed, provide
an opportunity for the individual to speak to the RPM or RP Management about
personnel monitoring. 5.
Provide accurate survey results to the worker in
ccpm. 6.
If decontamination is required explain the
process before any actions are taken. 7.
Ensure the individual that their privacy will be
protected at all times. Attachment 3:
PCE Classification Guidelines
*Safety glasses provided by the
station would not be counted as PCE.
Attachment 4: Personnel Contamination Event Log – Sample
RP Su RP Supervisor Review Reviewed By Print/Sign: _________________________/______________________________ Date: ________________________ Instruction
notes 1.
Next
sequential number starting at YY-XXX. 2.
Provide
as specific information as possible on work location so follow up surveys can
be obtained if necessary. 3.
Record
activity for all locations found. 4.
Check
both boxes if contamination was found on skin and clothing 5.
Record
the time of discovery 6.
Record
the time decon was completed 7.
Worker
sign acknowledging decontamination is complete and successful re-monitoring |
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