Principles of Radiation Protection
Practices:
a. Justification: No practice shall be adopted unless its introduction produces a
sufficient benefit to the exposed individual or to the society to offset the
radiation harm that it might cause.
b. Optimisation: All exposures shall be kept As Low As Reasonably Achievable
(ALARA) economic and social factors being taken into consideration.
c. Dose limitations: Individual exposures are limited by dose limits since the
dose above the dose limits are unacceptable
Intervention: The general principles of radiological protection for intervention are:
a. The reduction in dose should be sufficient to justify the harm and the costs to
the individual and the society due to the intervention.
b. The benefit of the reduction in dose less the cost of intervention should be As
Large As Reasonably Achievable.
c. Dose limits do not apply in case of intervention. However there will be some
projected dose levels above which intervention will be justified because of
serious deterministic effects.
Dose limits: Occupational Workers
a. For stochastic effects: The dose limit for uniform irradiation of the whole body
shall be 20 mSv (2 Rem) averaged over 5 years (January 1,1999 to December
31,2003) and shall not exceed 30 mSv (3 Rem) in a single year.
b. The average whole body dose for the occupational workers in the station
should normally not exceed 5 mSv (500 Rem).
c. For deterministic effects, the dose limit shall be 500 mSv (50 Rem) in a year
to Bone surface, Skin and for the lens of the eye, for which the limit shall be
150 mSv (15 Rem) in a year.
The whole body exposure level should Remain less 10 mSv (1 Rem) in any month
and 15 mSv (1.5 Rem) in any calendar quarter.
In case of intakes of radioactive material into the body, the total amount of activity
taken into the body in a calendar year shall not exceed one ALI (Annual Limit on
Intake).
Incase of exposure resulting from both external radiation and intake of radionuclides
in the body it shall be ensured that the sum of effective dose resulting from all such
exposures does not exceed the annual dose limits.
Whole body dose Ii -- + Σ -- < 1
0.02 Sv (ALI) I
Where Ii is the intake of the i th radio-nuclide and (ALI) i the ALI value for the i th
radio-nuclide.
Planned Exposure: Situation may occur in-frequently during normal operations when
it may be necessary to permit a few workers to receive dose in excess of the annual
whole body dose limit. In such circumstances, Station director may permit exposure
such that dose does not exceed 30 mSv in a single year and 20 mSv averaged over 5
years.
External Exposure Control: Any external whole body exposure that exceeds 5 mSv
(0.5 Rem) in any month is referred to as significant dose.
Internal Exposure Control
a. Proper ventilation of work areas and use of the recommended protective
equipment would avoid intake of radionuclides in the body.
b. In any case of actual or suspected high intakes HPU should be contacted for
advice and appropriate action.
KGS-Operating Manual on Radiation Protection Procedures
For assessment of internal exposure due to tritium, bioassay of urine will be taken as
the standard reference. For assessment of internal exposure by radionuclides other
than tritium bioassay and/ or whole body counting whichever is applicable will be
taken as standard reference. For control of intake of tritium the following procedures
shall be l Exposure Control followed:
Permissible Contamination levels
Air borne Contamination the levels of air borne contamination in working areas at
the station should be maintained below the Derived Air Concentration (DAC) values
DAC (Bq/m3) = ALI Bq/2400 m3
Investigation of Doses
Investigation levels Whole body dose: Committee (SDIC) shall investigate these
exposures
Dose Reference Levels for Investigation
Tissue/Organ Investigation Levels mSv (Rem)
Monthly Quarterly Yearly
Whole body 10 (1) 15 (1.5) 20 (2)
Skin 100 (10) 300 (30) 500 (50)
Lens of Eyes 30 (3) 80 (8) 150 (15)
The functions of SDIC:
a. To investigate fully the causes of the doses above the investigation levels and
to prepare a factual report.
b. To suggest Remedial measures to prevent recurrence of such doses.
c. To suggest further action in respect of work to be allocated to the exposed
person.
d. To recommend Remedial measure and medical follow up wherever necessary.
Exposure exceeding any of the limits stipulated below shall be regarded as
potentially serious:
Whole body dose: 100 mSv (10 Rem)
Exposure to Eye Lens: 300 mSv (30 Rem)
Such cases shall be referred to Head, Medical Group, BARC and Chairman,
SARCOP immediately
Head, Medical Group, BARC shall initiate appropriate medical investigation
Medical report shall be submitted to Chairman, SARCOP, within a week. Chairman,
SARCOP shall constitute a special committee for investigation of such exposures.
Tritium half life: Radiological =12.3 years, Biological = 7 days, tritium effective =
(TR *TB) / (TR +TB)
(12.3*365*7) / (12.3+365+7) = 7 Days
REVERSE SQUARE LAW: Dose at a rate form the point of source is inversely
proportional to the square of the distance. I is inversely proportional to L / d square
Technical specification Values: Fission products
Noble gases 14.8 TBq / day, Tritium = 13TBq/day, Ar 41 = 2.04 TBq / day,
I-131 = 185 MBq/day, Particulate = 1480 MBq / day
Liquids: Tritium = 1.295 TBq/day
RADIOACTIVE TRANSPORT INDEX: 1 meter from the source shield. Declaration
of radioactive material = 70 kiloBq / kg
Maintenance Performance Planning
1. Essential sequence of maintenance Jobs execution.
Identify maintenance jobs, asses safety, radiological precautions, plan the work,
do the pre-job briefing, take the safety and ALARA measures, carry out the
maintenance, test and normalise equipment or system, update records and history
cards, review maintenance performance and devise future strategy, achieve
excellence in maintenance through dedicated team work.
2. Maintenance performance indicator based on equipment & work control
Maintenance performance indicator (MPI) is the measure of performance of each
aspects of maintenance. These are established as convenient measures to evaluate
current performance levels against standard as well as an index to compare with
past performance
MPI base on equipment performance (EMPI)
a) Equivalent availability % (should be as high as possible)
Equipment operating time x 100
Equipment operating time + down time
b) Mean time between failures (MBTF) should be as high as possible
Number of operating hours
Number of failures/breakdowns
c) Meantime to repair (MTTR) as low as possible
Sum of repair time
Number of breakdowns
d) Number of plant outage caused due to equipment failure. (Objective should
be zero)
e) Number of respective failures during reporting period. (as low as possible)
f) Number of breakdowns during reporting period (As low as possible)
3. Maintenance Performance indicator based on work control
a. Work control indicator (WCI) should be near to unity
No. of DR received from control room per month
No. of PM jobs planned
4. Maintenance performance indicator based on maintenance man hours
1) Man hours spent on breakdown maintenance
2) Man hours spent on PM including implementation of ECN/FCN’s etc.
3) % man hours spent on breakdown maintenance
Man hours spent on = Breakdown maintenance 100
Total maintenance man hour available
4) % of man hours spent on PM
= Man hours spent on PM x 100
Total maintenance man hour available
• What is FME explaining with the examples?
Foreign material is defined as material that is not part of a system or component as
designed. This includes dirt, debris, broken or missing parts, slag, tools rags,
liquids/chemicals, lapping compounds, grinding particles and any other item that
would affect the intended operation of a system or component
All personnel shall assume responsibility for preventing the introduction of foreign
material into systems. This will minimize damage or harmful effects. Such as
corrosion, fuel damage, component malfunction, or failure, changes in chemistry.
Reduced heat transfer, increased radiation levels, changes in system flow
characteristic and improper contact operation.
Specific actions includes the following
Work packages will be planned using field walk downs to determine specific FME
recommendations
If temporary dams are installed which will not be readily visible upon system
closure, verification of removal shall be included in the checklist.
• What is the importance of communications?
Effective, open communication is essential for safe and efficient performance of
plant maintenance. Expressing concerns describing assignments, discussing
problems, are few aspects of maintenance of communication. Clear and
unambiguous communication is an integral part of procedure compliance and safe
work practice. The following additional communication practices will be followed.
a. Repeat back is used to ensure accurate communication, especially when portable
radios, headsets, or telephones are being used.
b. Upon completion of a task, technicians shall report job completions to their
supervisors and seek additional assignments.
c. To confirm to the principle of solving problems at the lowest possible level,
potential grievance issues are to be discussed with the first line supervisor.
d. Plant approved terminology, equipment identification and abbreviations are to be
used at all times.
e. 2-way communication is required at times!
f. Listen
g. Understand
h. Then reply or repeat message.
• Importance of self checking peer verification
a. STAR Principle
S- Stop pause before performing a task,
T- Think Understand exactly what is to be done before taking any action.
A- Act Touch the component without actuating it. Then do it.
R- Review, verifies that the actual responses is the expected response.
b. Self-checking is a self-verification step or action before it is performed. This
behavior is developed through constant checking to ensure the intended action is
correctly and positively performed on the right equipment. Consistently applied this
will minimize error by forming a barrier against complacency and over confidence.
All are responsible for conducting self-checking prior to manipulating a component
or devices, or altering equipment configuration. For examples relays, positioning
switches, breaker or valves, lifting/landing wires, connecting test equipment,
removing or installing fuses.
c. Any deficiency found in the field like labels, nameplate missing/tampered
should be intimated to the supervisor.
d. Do it right the first time.
e. Peer verification is achieved through the use of inspection points, these include
dual verification, independent verification, supervisory verification and quality
verification. Peer verification leads to a broader concept of checking other.
f. Questioning attitude should develop for continuously learning.
The distinction between predictive and periodic maintenance is presented below.
a. Use predictive maintenance results to trend and monitor equipment performance
so that needed corrective or preventive maintenance can be performed before
equipment failure.
b. Predictive maintenance actions are determined by the data required to monitor
equipment condition.
Examples are as follows:
Vibration analysis (includes spectral analysis and bearing temperature
monitoring) and lubrication oil and grease analysis are used to monitor rotating
equipment.
Infrared surveys (thermography) are performed on heat producing equipment
such as motors, circuit breakers, batteries, load centers, bus ducts, transformers
and insulated areas to monitor for high resistance or insulation breakdown.
Oil analyses are performed on lubrication for rotating equipment to identify
degrading equipment and chemical breakdown of lubricants.
Motor operated valves are diagnostically tested and analysed. Tests determine
parameters such as run current, valve stem thrust and torque switch and limit
switch actuation points.
c. Periodic maintenance is time based action taken on equipment to prevent
breakdown and involves servicing such as lubrication, filter changes, cleaning,
testing, adjustments, calibration and inspection. Periodic maintenance can also be
initiated because of the results of predictive maintenance, vendor
recommendation, or experience. Examples are as follows:
a. Scheduled valve re-packing to avoid leakage based on previous experience.
b. Replacement of bearings or pump realignment as indicated from vibration
analysis and/or lubricating oil analysis
c. Major or minor overhauls based on experience or vendor
recommendations.
d. Maintenance on equipment belonging to a redundant safety system if so
allowed by the Technical Specifications
d. Preventive Maintenance Programme Effectiveness
Continually review the preventive maintenance programme for effectiveness, and
change if necessary based on changes in plant design, operating conditions,
regulatory commitments and as found conditions. In addition, unexpected
equipment failures should result in a critical self-assessment to determine why the
previous maintenance activities were insufficient to maintain equipment
reliability. The primary objectives of the programme are to reduce future
component failures, optimize preventive maintenance tasks and use of resources,
identify programme scope and satisfy regulatory and utility concerns. Emphasize
obtaining accurate feedback on preventive maintenance tasks. Enhancement,
provide additional guidance on methods to determine preventive maintenance
effectiveness.
• What are the advantages and disadvantages of planned maintenance?
Advantages of Planned Maintenance.
1. As the name reflects maintenance jobs planned properly ie. manpower, tools,
tackles, required for maintenance is well planned and readily available or
reserved for planned job
2. Procedures for doing the job in well known before doing the job and job can
be performed as per procedure/checklist.
3. It saves the time and unplanned outages of equipment.
4. Common facilities/tools/tackles/ in the section in the section can be made
available at the right time as job and requirements for that are already well
planned.
5. Overtime to employees can be limited.
6. Job can be done systematically, accurately as quality job can be expected.
Disadvantages of Unplanned maintenance.
1. Unplanned job won’t have any expectations when to start, when to stop.
2. Man power/tools tackles were available/not available at the right time is not
ensured.
3. Job may have to do in hurry which can lead to mistaken or job can be done
leisurely (no sufficient work front for the available manpower.) so wastage of
man machine tools etc.
4. In NPP we cannot accept unplanned jobs, as all works are safety
related/important.
• What is pre-job briefing and post job briefing?
Pre-job briefing: Unit no, DR/WP/, USI/system/load, Job description, Eqpt history,
Scope of Job, Any special tool or equipment required, Safety/Alarm, Procedures,
expectation for the job, tech specifications requirements, communication, FME
requirements, environmental concepts, any abnormal conditions.
Post job briefing: Details of work done, difficulties faced, deficiency found, parts
replaced, experience to be communicated, review modification, review procedure,
any suggestions, drawing updating, updating of history card, completion of
checklist, any testing/logic checks required, clearance for surrendering permit.
• What are the activities by which performance of the station will be judged?
Activities of station by which performance is judged by public
a. Capacity factor.
b. Availability factor.
c. Radiation release (gas and liquid effluents).
d. Thermal release.
e. Man-rem.
f. Development programs.
g. Public awareness.
h. Usefulness of the plant product to the public.
i. Employment and other facilities provided to the local public.
j. The Basic amenities provided to the employees.
k. The standard of living of the employees.
l. The profit earned by the Plant.
m. The quality and cleanliness in and around the Plant.
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Practices:
a. Justification: No practice shall be adopted unless its introduction produces a
sufficient benefit to the exposed individual or to the society to offset the
radiation harm that it might cause.
b. Optimisation: All exposures shall be kept As Low As Reasonably Achievable
(ALARA) economic and social factors being taken into consideration.
c. Dose limitations: Individual exposures are limited by dose limits since the
dose above the dose limits are unacceptable
Intervention: The general principles of radiological protection for intervention are:
a. The reduction in dose should be sufficient to justify the harm and the costs to
the individual and the society due to the intervention.
b. The benefit of the reduction in dose less the cost of intervention should be As
Large As Reasonably Achievable.
c. Dose limits do not apply in case of intervention. However there will be some
projected dose levels above which intervention will be justified because of
serious deterministic effects.
Dose limits: Occupational Workers
a. For stochastic effects: The dose limit for uniform irradiation of the whole body
shall be 20 mSv (2 Rem) averaged over 5 years (January 1,1999 to December
31,2003) and shall not exceed 30 mSv (3 Rem) in a single year.
b. The average whole body dose for the occupational workers in the station
should normally not exceed 5 mSv (500 Rem).
c. For deterministic effects, the dose limit shall be 500 mSv (50 Rem) in a year
to Bone surface, Skin and for the lens of the eye, for which the limit shall be
150 mSv (15 Rem) in a year.
The whole body exposure level should Remain less 10 mSv (1 Rem) in any month
and 15 mSv (1.5 Rem) in any calendar quarter.
In case of intakes of radioactive material into the body, the total amount of activity
taken into the body in a calendar year shall not exceed one ALI (Annual Limit on
Intake).
Incase of exposure resulting from both external radiation and intake of radionuclides
in the body it shall be ensured that the sum of effective dose resulting from all such
exposures does not exceed the annual dose limits.
Whole body dose Ii -- + Σ -- < 1
0.02 Sv (ALI) I
Where Ii is the intake of the i th radio-nuclide and (ALI) i the ALI value for the i th
radio-nuclide.
Planned Exposure: Situation may occur in-frequently during normal operations when
it may be necessary to permit a few workers to receive dose in excess of the annual
whole body dose limit. In such circumstances, Station director may permit exposure
such that dose does not exceed 30 mSv in a single year and 20 mSv averaged over 5
years.
External Exposure Control: Any external whole body exposure that exceeds 5 mSv
(0.5 Rem) in any month is referred to as significant dose.
Internal Exposure Control
a. Proper ventilation of work areas and use of the recommended protective
equipment would avoid intake of radionuclides in the body.
b. In any case of actual or suspected high intakes HPU should be contacted for
advice and appropriate action.
KGS-Operating Manual on Radiation Protection Procedures
For assessment of internal exposure due to tritium, bioassay of urine will be taken as
the standard reference. For assessment of internal exposure by radionuclides other
than tritium bioassay and/ or whole body counting whichever is applicable will be
taken as standard reference. For control of intake of tritium the following procedures
shall be l Exposure Control followed:
Permissible Contamination levels
Air borne Contamination the levels of air borne contamination in working areas at
the station should be maintained below the Derived Air Concentration (DAC) values
DAC (Bq/m3) = ALI Bq/2400 m3
Investigation of Doses
Investigation levels Whole body dose: Committee (SDIC) shall investigate these
exposures
Dose Reference Levels for Investigation
Tissue/Organ Investigation Levels mSv (Rem)
Monthly Quarterly Yearly
Whole body 10 (1) 15 (1.5) 20 (2)
Skin 100 (10) 300 (30) 500 (50)
Lens of Eyes 30 (3) 80 (8) 150 (15)
The functions of SDIC:
a. To investigate fully the causes of the doses above the investigation levels and
to prepare a factual report.
b. To suggest Remedial measures to prevent recurrence of such doses.
c. To suggest further action in respect of work to be allocated to the exposed
person.
d. To recommend Remedial measure and medical follow up wherever necessary.
Exposure exceeding any of the limits stipulated below shall be regarded as
potentially serious:
Whole body dose: 100 mSv (10 Rem)
Exposure to Eye Lens: 300 mSv (30 Rem)
Such cases shall be referred to Head, Medical Group, BARC and Chairman,
SARCOP immediately
Head, Medical Group, BARC shall initiate appropriate medical investigation
Medical report shall be submitted to Chairman, SARCOP, within a week. Chairman,
SARCOP shall constitute a special committee for investigation of such exposures.
Tritium half life: Radiological =12.3 years, Biological = 7 days, tritium effective =
(TR *TB) / (TR +TB)
(12.3*365*7) / (12.3+365+7) = 7 Days
REVERSE SQUARE LAW: Dose at a rate form the point of source is inversely
proportional to the square of the distance. I is inversely proportional to L / d square
Technical specification Values: Fission products
Noble gases 14.8 TBq / day, Tritium = 13TBq/day, Ar 41 = 2.04 TBq / day,
I-131 = 185 MBq/day, Particulate = 1480 MBq / day
Liquids: Tritium = 1.295 TBq/day
RADIOACTIVE TRANSPORT INDEX: 1 meter from the source shield. Declaration
of radioactive material = 70 kiloBq / kg
Maintenance Performance Planning
1. Essential sequence of maintenance Jobs execution.
Identify maintenance jobs, asses safety, radiological precautions, plan the work,
do the pre-job briefing, take the safety and ALARA measures, carry out the
maintenance, test and normalise equipment or system, update records and history
cards, review maintenance performance and devise future strategy, achieve
excellence in maintenance through dedicated team work.
2. Maintenance performance indicator based on equipment & work control
Maintenance performance indicator (MPI) is the measure of performance of each
aspects of maintenance. These are established as convenient measures to evaluate
current performance levels against standard as well as an index to compare with
past performance
MPI base on equipment performance (EMPI)
a) Equivalent availability % (should be as high as possible)
Equipment operating time x 100
Equipment operating time + down time
b) Mean time between failures (MBTF) should be as high as possible
Number of operating hours
Number of failures/breakdowns
c) Meantime to repair (MTTR) as low as possible
Sum of repair time
Number of breakdowns
d) Number of plant outage caused due to equipment failure. (Objective should
be zero)
e) Number of respective failures during reporting period. (as low as possible)
f) Number of breakdowns during reporting period (As low as possible)
3. Maintenance Performance indicator based on work control
a. Work control indicator (WCI) should be near to unity
No. of DR received from control room per month
No. of PM jobs planned
4. Maintenance performance indicator based on maintenance man hours
1) Man hours spent on breakdown maintenance
2) Man hours spent on PM including implementation of ECN/FCN’s etc.
3) % man hours spent on breakdown maintenance
Man hours spent on = Breakdown maintenance 100
Total maintenance man hour available
4) % of man hours spent on PM
= Man hours spent on PM x 100
Total maintenance man hour available
• What is FME explaining with the examples?
Foreign material is defined as material that is not part of a system or component as
designed. This includes dirt, debris, broken or missing parts, slag, tools rags,
liquids/chemicals, lapping compounds, grinding particles and any other item that
would affect the intended operation of a system or component
All personnel shall assume responsibility for preventing the introduction of foreign
material into systems. This will minimize damage or harmful effects. Such as
corrosion, fuel damage, component malfunction, or failure, changes in chemistry.
Reduced heat transfer, increased radiation levels, changes in system flow
characteristic and improper contact operation.
Specific actions includes the following
Work packages will be planned using field walk downs to determine specific FME
recommendations
If temporary dams are installed which will not be readily visible upon system
closure, verification of removal shall be included in the checklist.
• What is the importance of communications?
Effective, open communication is essential for safe and efficient performance of
plant maintenance. Expressing concerns describing assignments, discussing
problems, are few aspects of maintenance of communication. Clear and
unambiguous communication is an integral part of procedure compliance and safe
work practice. The following additional communication practices will be followed.
a. Repeat back is used to ensure accurate communication, especially when portable
radios, headsets, or telephones are being used.
b. Upon completion of a task, technicians shall report job completions to their
supervisors and seek additional assignments.
c. To confirm to the principle of solving problems at the lowest possible level,
potential grievance issues are to be discussed with the first line supervisor.
d. Plant approved terminology, equipment identification and abbreviations are to be
used at all times.
e. 2-way communication is required at times!
f. Listen
g. Understand
h. Then reply or repeat message.
• Importance of self checking peer verification
a. STAR Principle
S- Stop pause before performing a task,
T- Think Understand exactly what is to be done before taking any action.
A- Act Touch the component without actuating it. Then do it.
R- Review, verifies that the actual responses is the expected response.
b. Self-checking is a self-verification step or action before it is performed. This
behavior is developed through constant checking to ensure the intended action is
correctly and positively performed on the right equipment. Consistently applied this
will minimize error by forming a barrier against complacency and over confidence.
All are responsible for conducting self-checking prior to manipulating a component
or devices, or altering equipment configuration. For examples relays, positioning
switches, breaker or valves, lifting/landing wires, connecting test equipment,
removing or installing fuses.
c. Any deficiency found in the field like labels, nameplate missing/tampered
should be intimated to the supervisor.
d. Do it right the first time.
e. Peer verification is achieved through the use of inspection points, these include
dual verification, independent verification, supervisory verification and quality
verification. Peer verification leads to a broader concept of checking other.
f. Questioning attitude should develop for continuously learning.
The distinction between predictive and periodic maintenance is presented below.
a. Use predictive maintenance results to trend and monitor equipment performance
so that needed corrective or preventive maintenance can be performed before
equipment failure.
b. Predictive maintenance actions are determined by the data required to monitor
equipment condition.
Examples are as follows:
Vibration analysis (includes spectral analysis and bearing temperature
monitoring) and lubrication oil and grease analysis are used to monitor rotating
equipment.
Infrared surveys (thermography) are performed on heat producing equipment
such as motors, circuit breakers, batteries, load centers, bus ducts, transformers
and insulated areas to monitor for high resistance or insulation breakdown.
Oil analyses are performed on lubrication for rotating equipment to identify
degrading equipment and chemical breakdown of lubricants.
Motor operated valves are diagnostically tested and analysed. Tests determine
parameters such as run current, valve stem thrust and torque switch and limit
switch actuation points.
c. Periodic maintenance is time based action taken on equipment to prevent
breakdown and involves servicing such as lubrication, filter changes, cleaning,
testing, adjustments, calibration and inspection. Periodic maintenance can also be
initiated because of the results of predictive maintenance, vendor
recommendation, or experience. Examples are as follows:
a. Scheduled valve re-packing to avoid leakage based on previous experience.
b. Replacement of bearings or pump realignment as indicated from vibration
analysis and/or lubricating oil analysis
c. Major or minor overhauls based on experience or vendor
recommendations.
d. Maintenance on equipment belonging to a redundant safety system if so
allowed by the Technical Specifications
d. Preventive Maintenance Programme Effectiveness
Continually review the preventive maintenance programme for effectiveness, and
change if necessary based on changes in plant design, operating conditions,
regulatory commitments and as found conditions. In addition, unexpected
equipment failures should result in a critical self-assessment to determine why the
previous maintenance activities were insufficient to maintain equipment
reliability. The primary objectives of the programme are to reduce future
component failures, optimize preventive maintenance tasks and use of resources,
identify programme scope and satisfy regulatory and utility concerns. Emphasize
obtaining accurate feedback on preventive maintenance tasks. Enhancement,
provide additional guidance on methods to determine preventive maintenance
effectiveness.
• What are the advantages and disadvantages of planned maintenance?
Advantages of Planned Maintenance.
1. As the name reflects maintenance jobs planned properly ie. manpower, tools,
tackles, required for maintenance is well planned and readily available or
reserved for planned job
2. Procedures for doing the job in well known before doing the job and job can
be performed as per procedure/checklist.
3. It saves the time and unplanned outages of equipment.
4. Common facilities/tools/tackles/ in the section in the section can be made
available at the right time as job and requirements for that are already well
planned.
5. Overtime to employees can be limited.
6. Job can be done systematically, accurately as quality job can be expected.
Disadvantages of Unplanned maintenance.
1. Unplanned job won’t have any expectations when to start, when to stop.
2. Man power/tools tackles were available/not available at the right time is not
ensured.
3. Job may have to do in hurry which can lead to mistaken or job can be done
leisurely (no sufficient work front for the available manpower.) so wastage of
man machine tools etc.
4. In NPP we cannot accept unplanned jobs, as all works are safety
related/important.
• What is pre-job briefing and post job briefing?
Pre-job briefing: Unit no, DR/WP/, USI/system/load, Job description, Eqpt history,
Scope of Job, Any special tool or equipment required, Safety/Alarm, Procedures,
expectation for the job, tech specifications requirements, communication, FME
requirements, environmental concepts, any abnormal conditions.
Post job briefing: Details of work done, difficulties faced, deficiency found, parts
replaced, experience to be communicated, review modification, review procedure,
any suggestions, drawing updating, updating of history card, completion of
checklist, any testing/logic checks required, clearance for surrendering permit.
• What are the activities by which performance of the station will be judged?
Activities of station by which performance is judged by public
a. Capacity factor.
b. Availability factor.
c. Radiation release (gas and liquid effluents).
d. Thermal release.
e. Man-rem.
f. Development programs.
g. Public awareness.
h. Usefulness of the plant product to the public.
i. Employment and other facilities provided to the local public.
j. The Basic amenities provided to the employees.
k. The standard of living of the employees.
l. The profit earned by the Plant.
m. The quality and cleanliness in and around the Plant.
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