# Presentation: 474773

## ELECTRICAL SAFETYFOR RADIOLOGICAL CONTROL TECHNICIANS

**EFCOG Electrical Safety Task Group**
**Module 7 **

**Notes:**
This class is designed to raise the electrical hazard awareness of the Health Physics technicians , using photos of various electrical hazards.

You may choose to insert photos from your own work site.

## ELECTRICAL SAFETY FOR RCT’S

**Batteries Stored on shelves**
**Unprotected with easy access**

**Notes:**
Pictured are batteries stored in an area accessible to everyone.

The Hazards presented would be:
 laying a metal object across the terminals causing a short circuit.  
 Damaging the battery Jars (case) causing an acid leak.
  Corrosion of the shelving from acid.
  shorting the terminal on the metal shelving while lifting the battery from the shelf.

Area should be accessible to qualified individuals only, battery terminals insolated and batteries stored in a spill containment tray.

## ELECTRICAL SAFETY FOR RCT’S

**Exposed Electrical above bleed valves**

**ELECTRICAL SAFETY FOR RCT’S**

**Notes:**
Looking down into a hydraulic pump unit used to operate a vehicle barrier.

Interesting design; a PVC drum enclosing the hydraulic fluid, pump, valves, piping, and electrical connections.

The task required Millwrights to operate the valves in the lower half of the unit.  This would mean working well within the Limited approach boundary of the electrical wiring.  Steps must be taken to eliminate the electrical hazard prior to reaching into the drum.

## ELECTRICAL SAFETY FOR RCT’S

**Shock or Arc Flash Hazard Exposed to operate Switch**

**ELECTRICAL SAFETY FOR RCT’S**

**Notes:**
Old design methods no longer meet NFPA 70E requirements.

Opening a box or Stack cabinet with exposed wires to operate a switch or take a reading is no longer an acceptable design.  When you encounter this situation stop work and contact your electrical POC.  An Arc Flash and shock hazard analysis must be completed to ensure worker safety before proceeding.

## Idaho National Laboratory, Radioactive Waste Management Complex

- 	On May 10, 2006 an RCT reported feeling an electrical shock on his bare right forearm as he was removing the electrical cord plug of a Continuous Air Monitor (CAM) vacuum pump from around the side and back of an Uninterruptible Power Supply (UPS). He felt what he considered to be an electrical shock when his forearm came into contact with the outside case of the UPS as he removed the 110 volt plug from the receptacle located on the back of the UPS.

**ELECTRICAL SAFETY FOR RCT’S**

**Notes:**
Example of RCT shocked by exposed electrical parts.

## RCT RECEIVES SHOCK WHILE STARTING A CAM VACUUM PUMP

- 	The RCT inadvertently brushed his right outer forearm against the exposed 110 volt electrical components.  As a result, he received a mild electrical shock since he was grounded by the beta CAM metal rack.  The RCT reported the incident to his manager and stated that he felt fine. The RCT was escorted to the First Aid stations for observation and was then escorted to the Hanford Environmental Health Foundation (HEHF) for further evaluation.

**Notes:**
The rest of the story FYI this is a hidden slide for instructor info only

## Unexpected Electrical Hazards

_**RCT RECEIVES SHOCK WHILE STARTING A CAM VACUUM PUMP**_

- On 08/23/95, a Radiological Controls Technician (RCT) at T Plant received a mild shock when his hand brushed energized contacts inside an instrument cabinet.  He was starting a vacuum pump for a continuous air monitor (CAM) and reached into the cabinet to verify pump operation.  He was not injured.

**Notes:**
Examples Continued

## Burned Wire on PCM-2 Personnel Contamination Monitor Causes Facility Evacuation 

- 	On 12/29/05 after exiting the 105KE Basin and proceeding to the PCM-2, an operator observed that the displays on the monitor were not working and heavy smoke was coming out of the top of the unit. The facility was evacuated and the monitor was unplugged. When Hanford Fire Department (HFD) personnel arrived they found no fire or smoke coming from the monitor.

## Burned Wire on PCM-2 Personnel Contamination Monitor Causes Facility Evacuation 

- An Eberline Personnel Contamination Monitor (PCM-2) at the 105KE facility experienced a "loose wire" that caused an electrical short. The short caused wiring insulation to burn, which cause heavy smoke to emanate from the top of the instrument, leading to a facility evacuation.

**Notes:**
More on the story

## Instrument Technicians found burned insulation on a six-foot section of wire associated with a photocell on the foot pad. The wire had loosened and sagged over time, eventually pulling free and shorting out. The smoke was preceded by an intermittent failure of the PCM-2 to count continuously when the worker switched from the front count to the back count. 

- _Burned Wire on PCM-2 Personnel Contamination Monitor Causes Facility Evacuation_

**Notes:**
More on the story

## Burned Wire on PCM-2 Personnel Contamination Monitor Causes Facility Evacuation

- Inspection of other units in the facility found loose/sagging wires on two of three similar monitors, which were subsequently repaired.
- Eberline, the manufacturer, is aware of this issue and has made available a harness kit for these instruments that will reroute and properly secure the wires away from the foot area of the PCM-2. Owners of PCM-2 Personnel Contamination Monitors should check their units for similar problems.

**Notes:**
More on the story

## Unexpected Electrical Hazards

**Unguarded Temporary Light**
**Exposes energized parts.**

**Unexpected Electrical Hazards**

**Notes:**
All Temporary lights are required to have some type of guard covering the light bulb.

In this situation energized parts are exposed.

It’s just a matter of time till someone makes contact with the hazard or rocks it over against the metal scaffold causing it to short out.  Or even worse energizing all the metal parts of the scaffold not completing the return path until someone comes along and grabs hold of the scaffold leg. 

Here at Hanford our work force is trained to recognize electrical hazards through the
OSHA Electrical Cord and Power Tool Safety class Course #044480 (old medium risk electrical class).

## Working on or NearExposed Energized Parts

**	****Unqualified Persons, Safe Approach Distance:**
**Unqualified persons are safe when they maintain a distance from the exposed energized conductors or circuit parts.**
**The safe approach distance is the ****Limited Approach Boundary.**

**Notes:**
As an RCT assisting Electrical workers in the field you could often encounter Exposed Energized Parts the safe approach distance is call the Limited Approach Boundary (LAB) 

**LAB**
**50 to 300 V **
**Exposed Movable Parts**
**10 feet**

**LAB**
**50 to 300 V **
**Exposed Fixed Parts**
**3.5 feet**

**Notes:**
There are several Shock Protection Boundaries but the one to remember is the Limit Approach Boundary. Notice for movable parts its 10 ft, and for fixed parts its 3.5 ft.Rule of thumb stay 10 ft away.  Notice you may be allowed to enter the Limited Approach Boundary if advised and escorted by a qualified person.

Work with the electricians on your required swipes let them do the reaching in they know the hazards and can dress accordingly.

## NFPA 70E Standard for Electrical Safety Requirements for Employee WorkplacesTable 2-1.3.4 Approach Boundaries to Live Parts for Shock Protection. (All dimensions are distance from live part to employee.)  

| (1) | (2) | (3) | (4) | (5) |
| --- | --- | --- | --- | --- |
|  | Limited Approach 
Boundary1   |  | Restricted Approach 
Boundary1  |  |
| Nominal System Voltage Range, Phase to Phase   | Exposed Movable Conductor   | Exposed Fixed Circuit Part   | Includes Inadvertent Movement Adder   | Prohibited Approach 
Boundary1   |
| 0 to 50   | Not specified   | Not specified   | Not specified   | Not specified   |
| 51 to 300   | 10 ft 0 in.   | 3 ft 6 in.   | Avoid contact   | Avoid contact   |
| 301 to 750   | 10 ft 0 in.   | 3 ft 6 in.   | 1 ft 0 in.   | 0 ft 1 in.   |
| 751 to 15 kV   | 10 ft 0 in.   | 5 ft 0 in.   | 2 ft 2 in  | 0 ft 7 in.   |
| 15.1 kV to 36 kV   | 10 ft 0 in.   | 6 ft 0 in.   | 2 ft 7 in.   | 0 ft 10 in  |
| 36.1 kV to 46 kV   | 10 ft 0 in.   | 8 ft 0 in.   | 2 ft 9 in.   | 1 ft 5 in.   |
| 46.1 kV to 72.5 kV   | 10 ft 0 in.   | 8 ft 0 in.   | 3 ft 3 in.   | 2 ft 1 in.   |
| 72.6 kV to 121 kV   | 10 ft 0 in.   | 8 ft 0 in.   | 3 ft 2 in.   | 2 ft 8 in.   |
| 138 kV to 145 kV   | 11 ft 0 in.   | 10 ft 0 in.   | 3 ft 7 in.   | 3 ft 1 in.   |
| 161 kV to 169 kV   | 11 ft 0 in.   | 11 ft 8 in  | 4 ft 0 in.   | 3 ft 6 in.   |

**Notes:**
So where do these Limits come from.NFPA 70EIn our daily lives we are protected for the hazards of electricity by National Electric Codes which insure buildings are safe for occupancy.National Fire Protection Association 70E insures worker safety keeping us safe during the work activities prior to having safe complete installation.
Here is the table identifying approach boundaries for  Shock Protection.

## NFPA 70E Standard for Electrical Safety Requirements for Employee WorkplacesTable 2-1.3.4 Approach Boundaries to Live Parts for Shock Protection. (All dimensions are distance from live part to employee.)  

| (1) | (2) | (3) | (4) | (5) |
| --- | --- | --- | --- | --- |
|  | Limited Approach 
Boundary1   |  | Restricted Approach 
Boundary1  |  |
| Nominal System Voltage Range, Phase to Phase   | Exposed Movable Conductor   | Exposed Fixed Circuit Part   | Includes Inadvertent Movement Adder   | Prohibited Approach 
Boundary1   |
| 230 kV to 242 kV   | 13 ft 0 in  | 13 ft 0 in  | 5 ft 3 in.   | 4 ft 9 in.   |
| 345 kV to 362 kV     | 15 ft 4 in.   | 15 ft 4 in.   | 8 ft 6 in.   | 8 ft 0 in.   |
| 500 kV to 550 kV   | 19 ft 0 in.   | 19 ft 0 in.   | 11 ft 3 in.   | 10 ft 9 in.   |
| 765 kV to 800 kV   | 23 ft 9 in  | 23 ft 9 in  | 14 ft 11 in.   | 14 ft 5 in  |

**Notes:**
Hidden Slide will not show during presentation.If your audience needs to see the approach distances for higher voltages simple right click on the slide and select HIDE SLIDE.

## Working on or NearExposed Energized Parts

**	****The Flash Protection Boundary is 4 ft. for systems **_**600 volts**_** and below unless calculated otherwise under engineering supervision.  **

**Notes:**
Are the Flash Protection Boundaries different for then Shock Protection?

Actual Arc Flash Calculations may change the Flash Protection Boundary.

**Notes:**
Here is a graphic image of Flash Protection Boundary.

The thing to notice is that the Flash Protection Boundary only protects you from 2nd Degree Burns.

## Temperature And Heat Data

**Curable burn temperature (1/10sec)****	****             145 °F**
**Cell death temperature (1/10 sec)****	****	****   205 °F**
**Temperature at arc terminals                   35,000  °F**
**Temperature of suns surface                     9,000  °F**
**Temperature of burning clothing               1,400  °F**
**Clothing ignition temperature          700 to 1,400 °F **
**Temperature of metal droplets****	****         1,800  °F **

**Notes:**
Move quickly through the next few slides all you are trying to do is instill a healthy respect for an Arc Flash.

Arc Flash Accidents are rare enough that we tend to become complacent.
Some temperature comparisons might help restore a healthy respect. 

## Working on or NearExposed Energized Parts

**	****Unqualified Persons, Safe Approach Distance:**
**Unqualified persons must not cross the Flash Protection Boundary unless they are wearing the appropriate PPE and under the supervision of a qualified person****. **

**Notes:**
When would you cross the Flash Protection Boundary?

## Slide 21

**Notes:**
What we are looking at here is a list of the types of burns and the percentage of the total each type represents.

Notice Electrical burns account for only 8% of the total number of burns but of the 8% almost 90% resulted in a permanent disability.

## Slide 22

**Notes:**
Review the LAB for Shock Protection and the Flash Protection Boundaries.

Rule of thumb till determinations are made 10ft.

## CPP 1982 Roll in Breaker

**CPP**** ****1982**** ****Roll**** ****in**** ****Breaker**

**Notes:**
Here is a photo of a Roll in Breaker.Keep in mind the approach boundaries as shown on the model to the left.

## CPP 1982 Roll in Breaker

**CPP**** ****1982**** ****Roll**** ****in**** ****Breaker**

**Notes:**
Here is the same Roll in Breaker after a fault.Which approach boundary would you want to be in?

## CPP 1982 Roll in Breaker

**CPP**** ****1982**** ****Roll**** ****in**** ****Breaker**

**Notes:**
Again which approach boundary do you choose?

## Consequences of an Arc-Flash Incident

**Notes:**
There was a serious arc-flash accident at SLAC in October of 2004.  

The electrical worker suffered serious burns while installing a circuit breaker in an ENERGIZED 400 Amp 480 VAC electrical panel. Surprisingly, this type of energized work at SLAC was found to be rather routine.

SLAC was shutdown for months.  All of the Office of Science Labs were impacted.  

We don’t want [Your Organization] to be the next example.  We don’t want [Your Organization] to be shutdown for an avoidable accident. 

## Consequences of an Arc-Flash Incident

**Consequences of an Arc-Flash Incident**

| Review the list of items shown in slide.
In this case the worker wasn’t shocked he was caught in an Arc Flash. |
| --- |

**Notes:**
Review the list of items shown in slide.  In this case the worker wasn’t shocked he was caught in an Arc Flash.

What if this job had been in a Contamination Area and you had been assigned to cover this job

## Brookhaven 4/2006 Arc-Flash Incident

**Brookhaven 4/2006 Arc-Flash Incident**

**Notes:**
Keep in mind all covers were in place at the time of the Arc-Flash Incident

## Brookhaven 4/2006 Arc-Flash Incident

**Brookhaven 4/2006 Arc-Flash Incident**

**Notes:**
Closer View

## Brookhaven 4/2006 Arc-Flash Incident

**Brookhaven 4/2006 Arc-Flash Incident**

**Notes:**
What went on behind those panel covers.

## Brookhaven 4/2006 Arc-Flash Incident

**Brookhaven 4/2006 Arc-Flash Incident**

**Notes:**
Resulting injuries even with the doors closed.

## Arc Flash Protection Boundary 

| Voltage | Boundary |
| --- | --- |
| up to 750V  | 3 feet  |
| 750V to 2kV  | 4 feet  |
| 2kV to 15kV  | 16 feet  |
| 15kV to 36kV  | 19 feet  |
| over 36kV  | Must be Calculated |

## Common Electrical Exposures for RCTs

## Slide 34

**Notes:**
Changing the batteries in your PAM’s.

Just don’t put them in backward.

## Slide 35

**Notes:**
Popies

## Slide 36

**Notes:**
So what’s under that mylar?

## Slide 37

**Notes:**
Thin wires that are hard to see.  But what’s the voltage?

## Slide 38

**Notes:**
So what does that mean?  Have you ever been bite by a spark plug wire?

Also be aware of the connection points

## 2100 Volts DC

**2100 Volts DC**

## Eberline CAM 

**Eberline CAM **

**Notes:**
Don’t be sticking your forceps inside the CAM to retrieve sample paper. 

## Canberra CAM

**Canberra CAM**

**Notes:**
Same thing be aware of wires and terminal strips where ever they’re found.

## Electricity is a part of our daily lives, harness its power but recognize the hazards.

**Electricity is a part of our daily lives, harness its power but recognize the hazards.**

**Notes:**
In Summery:
There are electrical Hazards every where we turn.

Electricity is a part of our daily lives, harness its power but recognize the hazards

Never hesitate to ask “is that safe?”