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TRANSCRIPT
STATEMENT OF TECHNICAL REQUIREMENTS
DIGITAL GENERAL PURPOSE RADIATION SURVEY METER
EED5041
Jul 2013
ISSUING AUTHORITY
DIRECTORATE OF ELECTRICAL ENGINEERING
I N T E G R A T E D H E A D Q U A R T E R S
M O D ( N A V Y )
N E W D E L H I 1 1 0 0 1 1
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RECORD OF AMENDMENTS
Sl Amendment Authority Date Signature
Revision Note: Nil
Historical Record: Nil
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CONTENTS
SL No Description Page No1. Scope 5
2. Scope of Supply 5
3. Quantity 5
4. General Requirements 5
5. Design Requirements 57
6. Technical Requirements 78
7. Operation Requirements 89
8. Applicable Tests and Specifications 910
9. Governing Specifications 10
10. Binding Data, Design Drgs & Technical specifications 1112
11. Information to be supplied while Tendering 13
12. Onboard Spares 13
13. Training 1314
14. Dockyard Support Package 14
15. Five Year Base & Depot Spares/ Comprehensive Part Lists 13
16. Inspection & Testing 14
17. Quality Plan 15
18. Factory Acceptance Trial (FAT) 1415
19. System Performance Responsibility 16
20. Other Terms & Conditions (Transportation, Product Support, Maintenances, Security, Warranty etc) 1718
21. FACT Sheet (Appendix A) 1922
22. IN Maintenance Philosophy(Appendix B) 23
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STATEMENT OF REQUIREMENT FOR DIGITAL
GENERAL PURPOSE RADIATION SURVEY METER
1. Scope. This technical specification covers the manufacturing, testing, supply and commissioning of the Digital General Purpose Radiation Survey Meter for use onboard IN ships for detection and measurements of radiation levels during nuclear fall out or in a NBC environment.
2. Scope of Supply. The scope of supply will comprise one in number Digital General Purpose Radiation Survey Meter along with required batteries, specified detector, handle and customised stocking/carrying case.
3. Quantity. The number of General Purpose Radiation Survey Meter required on each ship will differ with the class of ship and the exact numbers will be specified in the Tender specifications.
4. General Requirements. The Digital General Purpose Radiation Survey Meter shall meet performance specification standards as specified in this document. It shall have rugged construction, be light in weight, user friendly and easy to handle. The meter shall be supplied in a customised case of non breakable material suitable to withstand shock and vibration during transportation/handling without causing any damage to the instrument.
5. Design Requirements. The Digital General Purpose Radiation Survey Meter shall be modular in design and conform to the latest International standards as applicable. All component used shall be of approved type and interchangeable with similar equipment. The design should be based on digitised micro controller using ‘low power’ electronic circuits provided with powerful fault diagnostics to identify the faults/failures. The meter shall meet the design specifications mentioned in the succeeding paragraphs.
5.1 Enclosure. The enclosure shall be portable and fabricated in Aluminium sheet of 2 mm size and shall conform to the ingress protection of IP56 specifications. The enclosure shall be compact in design and provided with suitable handle to hold when in use. The handle shall be fixed to the enclosure in position that it does not obstruct in operation during user interface. The enclosure shall be ruggedized to withstand the severe marine environment prevalent onboard ships.
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5.2 Painting. The enclosure shall be painted with epoxy polyester powder coated metal finish and Gray in colour.
5.3 Dimension and Weight. The size and weight of the meter shall be kept to a minimum consistent with electrical and mechanical requirements. The design dimension shall not be exceeding to 206L x 116W x 60D mm and shall not weigh more than 1.5 Kg.
5.4 Internal Wiring. Internal wiring shall be of Low Fire Hazard (LFH) cable only. The cable shall be provided with identification ferrules on both ends.
5.5 Talley Plates. The internal units and sub assemblies of the meter shall be provided with polycarbonate sticker type talley plates. Further, the functions of controls/switches provided on the enclosure for the operation of meter shall also be provided with talley plates.
5.6 Fault Diagnostic. The meter shall have builtin fault diagnostic and status scan programme for indication of failure of HV, detector, low battery indication etc. Further, module/PCB level failure shall also be indicated by the BITE.
5.7 Data Storage and Event Logging. The meter should have provision for online event logging with date and time stamped. It should be suitable to store up to 1000 measurements. The data to be retained using non volatile memory. Further, the Digital General Purpose Radiation Survey Meter shall be designed to interface with external PC based system on USB port serial communication protocol for displaying/transfer of data for archiving/analysis.
5.8 Power Supply. The instrument shall operate on battery power supply and all other secondary power supplies required for operation of internal modules of the meter shall be derived from the main battery power supply. The battery shall be of dry alkaline nonrechargeable type or rechargeable lithium ion batteries which is commercially available. The battery shall last for minimum 100 hours (without backlight) of operation and shelf life of minimum 3 years in stored condition battery cells being outside. Basic technical data of battery viz. Voltage, Current, and capacity in mAh shall be indicated. A low battery indication shall be provided on LCD display in case the battery voltage is below specified value. Customized batteries should not be used. In case, the equipment is provided with rechargeable batteries, a suitable charging kit shall be provided for recharging the battery from the secondary supply of the ship.
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5.9 Reliability and Operation Life. The Digital General Purpose Radiation Survey Meter shall be sensitive and reliable in operation. It should be user friendly and all readings/indications shall be well displayed and easy to read. The service life of the meter shall be 8 years or more. The operational life of the equipment shall be clearly mentioned by the supplier. The meter shall have high MTBF (minimum 1010
counts for detector) and the OEM shall submit necessary documents/certificates as basis for calculation of notified MTBF.
5.10 Detector Type. A miniature halogen quenched GM counter Type LND 713 with energy compensated filter provided by equipment manufacturer or detector type LND type 71310 or its equivalent. In case of equivalent detector its equivalent conformance chart given by detector manufacturer shall be provided.
5.11 Audio Visual Alarm. The meter shall be provided with builtin buzzer for generating audio chirps and indication by flashing LCD display or small red LED for radiation events and alarm higher than preset alarm values.
5.12 User Interface. The meter shall be provided with suitable user selectable soft keys for START, STOP, PROG, STORE, INC & DEC control functions. The number of keys shall be optimised (max. Six keys) for ease of user operation. These controls shall allow the user to programme and operate the survey meter.
5.13 LCD Display. An inbuilt 16x2 backlit Alpha numeric LCD display or Graphic LCD for showing dose rate / count rate apart from textual screens during configuration be provided.
6. Technical Requirements. The Digital General Purpose Radiation Survey Meter should conform to the following technical requirements:
Sno. Specification Sensitive/Condition (a) Radiation Detection Should be suitable to detect both X ray and
Gamma radiation from 60 Kev to 1.33 Mev intensity.
(b) Detector Sensitivity 7.5 CPS / mR/hr with Co60. Detector sensitivity be indicated.
(c) Measurement Unit (s) R/hr, Sv/hr & CPS(d) Measurement Range in
dose rate and count rate mode
Dose Rate: (0.01 to 10 R/hr); its equivalent in Sv/hr in 4 linear ranges.
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Count Rate: 0 99999 CPS in 5 linear ranges.
(e) Calibration Accuracy Within +/15% with Co 60 or Cs 137
(f) Range Selection Automatic(g) Response Time Less than 5 sec.(h)
Energy responseWithin +/ 20% in the range of 60 Kev to 1.33 Mev.
(j)Time constant
LO (2 sec), MED (4 sec) & HI (8 sec) switches automatically depending on count rate.
(k)
Preset Alarm Range
Should be provided throughout the range of 0.1 to 20 R/hr.
or1 to 99999 CPS
(l) Over range Unit shows over range above 10R/hr.
Note: Units of Measurement. Fact sheet on Radiation Measurement Units is placed at Appendix A. For ease of comprehension, the units of measuring radiation are elucidated as follows:
(a) mCi = milli curie where 1 Ci(Curie) = 1x103 mCi
(b) 1Ci = 3.7x 1010 DPS( Disintegration per Second) = 1 Bq ( Becqurel)
(c) 1Ci = 1x106 μCi
(d) 1 Sv/hr = 105 mr/hr (milli roentgen) ( Sv stands for Sievrt)
(e) Mr/hr is measured radiation energy absorption in one gm mass.
(f) Sv/hr is measured radiation energy absorption in one Kg mass.
(g) 1 Sv/hr = 100 R/hr
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(h) 1μR = 10 Svη
(j) 0.01 R/h = 10 mR/h
(k) 0.1R/h = 100mR/h
(l) 1R/h = 1000mR/h
7. Operation Requirements. The device should operate satisfactory in the marine environmental and other operating conditions enumerated in the succeeding paragraphs.
7.1 Sea Way Conditions. The limits of ships motion up to which the meter should be fully operational are listed below. These motions may not be concurrent. The instrument shall be capable of efficient and unrestricted operation without any deviation from its normal operating parameters under the following seaway conditions:
(a) Roll : Max. + 300 with 10 sec period Operational
(b) Pitch : Max. + 300 with 10 sec period
(c) List : Max. 200 from vertical (permanent) Survival
(d) Trim : Max. 50
7.2 Environment Conditions. The Digital General Purpose Radiation Survey Meter shall achieve designed parameters and function smoothly under tropical conditions. It shall withstand air contamination through oil, salt and other contaminants associated with the marine environment. The meter shall be suitable to operate under the following environmental conditions:
(a) Storage temperature : 0 to 75oC
(b) Operating temperature : 0 to 55oC
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(c) Humidity : 95% RH condensing at 35oC
(d) Vibration : Should be suitable for marine applications
8. Applicable Tests and Specifications. The first of the lot Digital General Purpose Radiation Survey Meter shall be subjected to the following tests as per the standard specified:
Sno. Test Details Specification(a)
Temperature test
The mean instrument response over the temperature range from 0 to 40o C shall be within 15% of the mean response determined at 22o C (ANSI N42.17A)
(b)
Temperature shock
An instrument’s response when exposed to a temperature change from 22o C to 10o C, 10o C to 22o C, 22o C to 50o C, and 50o C to 22o C in less than 5 min shall be within 20% of the response at 22o C. (ANSI N42.17A)
(c)
Humidity
The mean instrument response shall be within 15% of the mean instrument response determined at 40% relative humidity (RH) / 22o
C during and after exposure to a noncondensing RH range of 40% to 93% at 30o C.(ANSI N42.17A)
(d)
Mechanical shock
The mean instrument response for portable survey meters shall be within 15% of the reference reading after being subjected to 10 shock pulses of 50 g peak acceleration, each applied for a nominal 18 ms in each of three mutually orthogonal axes. The physical condition of instruments shall not be affected by these shocks (e.g., solder joints shall hold, nuts and bolts shall not come loose).(ANSI N42.17A)
(e) Vibration The mean instrument response shall be within 15% of the pre test response following exposure to vibrations of 2 g applied for 15 min in the frequency range of 10 Hz to 33 Hz. The physical condition of the instrument shall not be affected by this vibration (e.g., solder joints shall hold,
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nuts and bolts shall not come loose).(ANSI N42.17A)
(f)Corrosion
Salt spray for 2hrs. Storing at 35o C & 90% RH for 7 days. (JSS 55555:2000 Rev2)
(g)Ingress Protection
The enclosure shall comply to IP56 specifications.
(h)Toppling
Angle of toppling 45o, FOUR times in each of bottom edges.(JSS 55555:2000 Rev2)
(j)Driving rain test
For ONE hour at 200 Kpa water pressure, angel of spray 45o
(JSS 55555:2000 Rev2)(k) EMI/EMC IEC 6100043,2006 (Radiated Susceptibility)(l) Environmental Stress
Screening DQAN policy 6630/Policy17/DQAN/QA11 dated 15 Mar 12.
9. Governing Specifications. The performance of Digital General Purpose Radiation Survey Meter shall conform to the requirements specified in the under mentioned standards:
(a) Temperatures ANSI N42.17A2003 (b) Temperature shock ANSI N42.17A2003 (c) Humidity ANSI N42.17A2003 (d) Mechanical shock ANSI N42.17A2003 (e) Vibration ANSI N42.17A2003(f) Corrosion JSS 55555:2000 Rev2)(g) Ingress Protection
ratingIEC 60529 latest version
(h) Toppling JSS 555552000 REV2 (j) Driving rain test JSS 555552000 REV2 (k) EMI/EMC IEC 6100043,2006 (Radiated Susceptibility)(p) Binding Drawings JSS 02511
10. Binding data, Design Drawings and Technical documentation.
10.1 Binding Drawing. The manufacturers shall submit “as built” drawings sufficiently detailed to show the manner of construction and operation, the method of assembling and dismantling. The drawings shall be prepared in accordance with JSS 02511. The following binding drawing/documents in duplicate shall be submitted to IHQ/MoD (Navy) with in 46 weeks after placement of the LOI/order:
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(a) Overall dimensions with requirement of maintenance space, weight, power supply and CG of the meter.
(b) Terminal connection and circuit diagram.
(d) Part Identification /Part No., Quantity, Material, Makers name etc.
(e) Details of factory tests
10.2 Design Documents/Drawings. All associated design documentation, drawings and equipment list applicable must be in English language. All drawings and documents shall contain dimensions and other parameters in metric units (SI Units). These should cover all subassemblies and accessories of the meter. The documents/drawings shall be provided in both hard copy and on CD ROM. The design documents/drawings shall conform to NES 722 and supplied to include the following information:
(a) Drawing
(i) Block diagram of all major assemblies showing interconnection between these assemblies.
(ii) Type and size of cables and connectors.
(iii) Core connection details.
(b) Documentation
(i) General technical document/information
(ii) Operation maintenance document
(iii) Test data
(iv) Drawings in reduced size
(v) Any other special instructions for preservation
(vi) Heat dissipation of devices
(vii) Storage, handling, transportation details etc.
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(viii) Details for maintenance, repair and troubleshooting up to PCB level be provided.
(ix) Verification and Validation certificates for software/embedded code testing by a third party.
10.3 System Documentation. One set of the under mentioned documents be supplied with each Digital General Purpose Radiation Survey Meter as per JSS –025101.
Sno. Description
(a) User Handbook
(b) Technical Manual PartI (Technical description and circuit drawings)
(c) Technical Manual PartII Setting to work and test procedures
(d)Technical Manual PartIII Servicing and Maintenance Manual including troubling shooting (field and depot)
(e)Technical Manual PartIV Manufacturer’s Parts list, layout drawings of the PCBs and sub units.
(f) Unpacking procedures
(g)Recommended list of OB spares, testing tuning spares, tools and test jigs.
(h) As made drawings including performance data
(j) Test certificates
(k) Soft copies of above documents in CD ROM
(l)Back up software in suitable magnetic media along with procedure for loading.
11. Information to be supplied while Tendering. The Manufacturer should furnish the following details of the product:
(a) Complete / product technical data / specification
(b) Type test / Environmental tests that the statement of product will qualify.
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(c) Approved components are being used conformity.
(d) Product support in years; naval requirements are minimum for 10 years.
12. Onboard Spares. Itemized lists of OBS, special tools which will be supplied with the meter, are to be furnished along with the quotation for the Digital General Purpose Radiation Survey Meter. The OBS shall cater for onboard maintenance routines and possible repairs by ship’s staff. The OBS should include the following:
(a) All spares required for exploitation upto 2 years.
(b) One set of generalpurpose maintenance tools.
(c) One set of special tools required for disassembling/assembling of components to carry out repair by replacement.
13. Training. The Training program should enable the End User Personal to operate and maintain the Digital General Purpose Radiation Survey Meter. The Training package is to include the following:
(a) Basic Training. The manufacturer should undertake the responsibility of training naval personnel (including civilian personnel of the yard), as nominated by IHQ/MoD (N), on the exploitation and maintenance of the Digital General Purpose Radiation Survey Meter.. The duration of training and number of personnel should be worked out by the manufacturer in consultation with IHQ/MoD (N). Interactive multimedia training modules and suitable software for training on ESM and ECM features should be used for training and supplied with the system.
(b) Advanced Training. The manufacturer shall also undertake the training of naval and defence civilian personnel, in carrying out major repairs in the Naval dockyard by using Special Test Equipment/ Special Maintenance Equipment. The training shall include assembling and dissembling of the equipment upto PCB/Microcontroller level for undertaking 3 rd and 4th level of maintenance.
(c) CBTs. CBTs should cover the system as well as the subsystem and must cater for dual level of complexity, i.e. for operator level and maintainer levels. The CBTs must cover exploitation/operator training, elucidated functionalities of the system (working principle of the system, electrical
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diagrams, mechanical interaction and functional charts) and include trouble shooting modules. Complete check off list for repair and maintenance to be included.
(d) Static Model. One set of static scaled model with cut sections should be provided. This shall include the emulator/model of major OBS of the system to enable familiarisation training of trainees. (e) Simulator Software. Suitable software must be provided for carrying out training at locations designated by IN.
14. Dockyard Support Package. Dockyard facilities are to be used for repairing faulty modules. A consolidated test bench to test the Digital General Purpose Radiation Survey Meter would be required to be provided as part of Dockyard Support Package. Beyond first level maintenance facilities on board, the manufacturer would be required to setup requisite advance level maintenance facilities at locations (Naval dockyards) specified by IN as part of the Dockyard Support Package. Facilities which are required in the Yard as per the IN maintenance philosophy at Appendix ‘B’ should be projected by the manufacturer, along with the details of manpower required. Further, till such time the Dockyard Support Package is installed and commissioned, provision of AMC and RRC is to be provided by the OEM. The manufacturer will prepare and submit data on maintainability as follows:
(a) Maintainability Program.
(b) Maintainability Prediction.
15. Fiveyear Base & Depot Spares / Comprehensive Part Lists. The supplier shall recommend a list of base & depot spares, tools and test equipment. Such recommendations are to be in commensurate with the reliability of critical components and components used in the meter. The requirement of the required spares needs to be mentioned Following points in respect of spares of the equipment needs to be mentioned :
(a) The onboard, base and depot, testing & tuning spares and long term exploitation spares should be indicated with a standard part no for identification and traceability as per Navy’s standards.
(b) The basis of ranging and scaling to be clearly indicated.
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(c) Commitment from the manufacturer for continuous customer and spare support for a specified duration for the life of the equipment.
(d) Commitment to undertake up gradation of the spares if required due to non availability of the spares due to obsolescence
(e) Itemized cost for the proposed B&D spares.
(f) The list should clearly indicate the embedded parts and a softcopy of the embedded codes shall be provided with necessary porting equipment.
(g) The list should mention the weather the spares are COTS or Non COTS.
(h) The supplier is required to indicate the make and part no. of each item. The details of spares are to be provided in ILMS format (both hard copy and soft copy to be provided).
(j) Base spares recommendation is to cover maintenance / overhaul requirements for 5 years including two refits.
(k) The details of tools and STTE required for carrying out 3rd and 4th level maintenance to be included in the offer.
(l) The supplier shall provide average life of all B & D spares and specify the turnaround time required for repairs/replacement of each spare.
16. Inspection & Testing. The inspection and testing of the Digital General Purpose Radiation Survey Meter will be as per approved QAP and drawings by under mentioned authorities:
(a) Inspection Authority: DQA(N). (b) Receipt Inspection: Warship Overseeing Team (WOT) of IN at SHIPYARD.
(c) For ship trials: ETMA (MBI). The OEM to provision all necessary tools and source required for acceptance trials.
17. Quality Plan
17.1 Quality Assurance . The detailed design, material and workmanship shall be in accordance with the best worldwiderecognised marine practices to ensure reliability, durability and ease of maintenance, which comply with the ship’s
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requirements. The design shall be such that weight and size are reduced to the minimum practicable, ensuring no compromise in reliability or significant design criteria. A quality assurance programme is to be drawn by the manufacturer in consultation by the Inspecting Authority and shall obtain approval prior commencement of manufacturing.
17.2 Quality Assurance Programme
(a) Details of test, Quality equipment, test methods, preliminary qualification tests, etc is to be indicated. Shop floor tests prior to dispatch by supplier should be conducted.
(b) Quality assurance plan proposed and any subsequent amendment shall be discussed and agreed upon between Naval Headquarters and the manufacturer at TNC stage i.e. prior to placement of the order.
17.3 The product offered by the manufacturers should conform to Standard Engineering practices. The equipment will be subject to stage inspection and final test and trials by the Naval Inspection Agencies as mutually agreed with the equipment manufacturers. Any deviation from the mentioned specifications will have to be brought to the notice of IHQ/MoD (Navy) and approval to be taken from the same.
18. Factory Acceptance Arial (FAT) . The supplier shall prepare a draft Factory Acceptance Trails (FATs) and forward to IHQ MoD(N) for approval. The FATs will be witnessed by personnel from Indian Navy as per the approved FATs document. The plan should state how the supplier would demonstrate that the delivered system will meet the functional and performance requirements indicated as per Indian Navy’s SOTR. The factory acceptance trials procedure shall comprise of:
(a) Functional tests
(b) Verification of design
(c) List of Test equipment required and calibration procedure
(d) Pass /Fail criteria
(e) Expected duration
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19. System Performance Responsibility. In case of any irregularities in the operation/performance of the system or nonconformance to specified parameters observed during installation and on integration with ships system, the supplier is bound to rectify the defect. The supplier shall ensure complete responsibility for satisfactory operation of the fixtures on board.
20. Other terms and conditions
20.1 Transportation. The Digital General Purpose Radiation Survey Meter should be packed and protected with supports to ensure protection during all modes of transportation. Each unit within a package/container shall be clearly marked for identification. The container shall clearly indicate the item description with caution marks, quantity, weight, size, etc., A separate document giving complete details and instructions for storage, preservation, handling and transportation after delivery is to be supplied. The supplier should indicate the delivery schedule, port of embarkation, transport, packing, preservation, insurance, etc.
20.2 Product Support . The supplier should undertake to ensure guaranteed and continuous product support for a period of 10 years from the date of supply of the first system and associated equipment, by way of the following:
(a) Supply of spare parts and materials.
(b) Offering of alternative solutions in the event of obsolescence of the components/technologies, including those bought out or subcontracted.
(c) Continuous upgradation program.
(d) Modifications and repairs.
(e) Provide at least two years notice, in the event of any likely production shut down (only after 15 years of support) to enable procurement of LTE spares.
(f) Undertake repairs through Annual Maintenance Contract/Rate Contracts as and when directed by the user / IHQ MoD(N).
(h) Continuous supply of amendments to the documentation.
20.3 Maintenance and Repair Infrastructure . The 1st/2nd level maintenance will be carried by SS and 3rd and 4th level maintenance support will be provided by the vendor on the basis of Annual Maintenances Contract and the cost of AMC shall not
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exceed the 10 % of the total value of the equipment. The additional infra structure that would be necessary for the maintenance and repairs of the system should also be catered for along with the system induction. The facility for repairs up to the fourth level which caters for PCB repairs is to be known. These are to be specified by the OEM. These should include special to type test equipments and system wise test jigs in addition to the general purpose test equipments.
20.4 Warranty. The Digital General Purpose Radiation Survey Meter with associated controls / probes and instrumentation will be guaranteed for stipulated performance as agreed between the buyer and the supplier. The items supplied shall be warranted from defects arising due to the manufacturer and performance for the said period and cover all the defects arising from malfunction through design faults, inappropriate material, bad production and nonconformance to specifications. Any expense on account of repair/supply of spares against guarantee defects is to be borne by the supplier.
20.5. Pre Bid Meeting. A Pre bid Meeting to clarify SOTR issues would be held and queries, if any, would be clarified during the same.
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Appendix B
(Refers to para 6 at page 8)
FACT SHEET
1. Radiation Measurement . When scientists measure radiation, they use different terms depending on whether they are discussing radiation coming from a radioactive source, the radiation dose absorbed by a person, or the risk that a person will suffer health effects (biological risk) from exposure to radiation. This fact sheet explains some of the terminology used to discuss radiation measurement.
2. Units of Measure . Most scientists in the international community measure radiation using the System Internationale (SI), a uniform system of weights and measures that evolved from the metric system. Different units of measure are used depending on what aspect of radiation is being measured. For example, the amount of radiation being given off, or emitted, by a radioactive material is measured using the conventional unit curie (Ci), named for the famed scientist Marie Curie, or the SI unit Becquerel (Bq). The radiation dose absorbed by a person (that is, the amount of energy deposited in human tissue by radiation) is measured using the conventional unit rad or the SI unit gray (Gy). The biological risk of exposure to radiation is measured using the conventional unit rem or the SI unit sievert (Sv).
3. Measuring Emitted Radiation . When the amount of radiation being emitted or given off is discussed, the unit of measure used is the conventional unit Ci or the SI unit Bq. A radioactive atom gives off or emits radioactivity because the nucleus has too many particles, too much energy, or too much mass to be stable. The nucleus breaks down, or disintegrates, in an attempt to reach a nonradioactive (stable) state. As the nucleus disintegrates, energy is released in the form of radiation. The Ci or Bq is used to express the number of disintegrations of radioactive atoms in a radioactive material over a period of time. For example, one Ci is equal to 37 billion (37 X 109) disintegrations per second. The Ci is being replaced by the Bq. Since one Bq is equal to one disintegration per second, one Ci is equal to 37 billion (37 X 109) Bq. Ci or Bq may be used to refer to the amount of
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radioactive materials released into the environment. For example, during the Chernobyl power plant accident that took place in the former Soviet Union, an estimated total of 81 million Ci of radioactive cesium (a type of radioactive material) was released. Measuring Radiation Dose When a person is exposed to radiation, energy is deposited in the tissues of the body. The amount of energy deposited per unit of weight of human tissue is called the absorbed dose. Absorbed dose is measured using the conventional rad or the SI Gy. The rad, which stands for radiation absorbed dose, was the conventional unit of measurement, but it has been replaced by the Gy. One Gy is equal to 100 rad.
4. Measuring Biological Risk . A person's biological risk (that is, the risk that a person will suffer health effects from an exposure to radiation) is measured using the conventional unit rem or the SI unit Sv. To determine a person's biological risk, scientists have assigned a number to each type of ionizing radiation (alpha and beta particles, gamma rays, and xrays) depending on that type's ability to transfer energy to the cells of the body. This number is known as the Quality Factor (Q). When a person is exposed to radiation, scientists can multiply the dose in rad by the quality factor for the type of radiation present and estimate a person's biological risk in rems. Thus, risk in rem = rad X Q. The rem has been replaced by the Sv. One Sv is equal to 100 rem.
5. Abbreviations for Radiation Measurements . When the amounts of radiation being measured are less than 1, prefixes are attached to the unit of measure as a type of shorthand. This is called scientific notation and is used in many scientific fields, not just for measuring radiation. The table below shows the prefixes for radiation measurement and their associated numeric notations are mentioned below:
Prefix Equal to Which is this much Abbreviation Exampleatto 1 X 1018 .000000000000000001 a aCi
femto 1 X 1015
.000000000000001 f fCi
pico 1 X 1012
.000000000001 p pCi
nano 1 X 109
.000000001 n nCi
micro 1 X 106
.000001 μ μCi
milli 1 X 103 .001 m mCicenti 1 x 102 .01 c cGy
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When the amount to be measured is 1000 (that is, 1 X 103) or higher, prefixes are attached to the unit of measure to shorten very large numbers (also scientific notation). The table below shows the prefixes used in radiation measurement and their associated numeric notations are mentioned below:
Prefix Equal to Which is this much Abbreviation Examplekilo 1 X 103 1,000 k kcimega 1 X 106 1,000,000 M MCigiga 1 X 109 1,000,000,000 G GBqtetra 1 X 1012 1,000,000,000,000 T TBqpeta 1 X 1015 1,000,000,000,000,000 P PBqexa 1 x 1018 1,000,000,000,000,000,000 E EBq
6. Dosages of Nuclear Radiation to Humans . Nuclear radiation has a major effect on matter, since nuclear radiation has an energy which is very high relative to the energies of chemical reactions absorption of nuclear radiation by matter causes many chemical reactions to take place. When the matter which is the target is living tissue, these chemical reactions cause serious injury or death. Quantitative measurement of nuclear radiation involves two types of units, those units which measure physical nuclear radiation itself and those units which measure the biological effect of nuclear radiation. Physical radiation units measure the activity of a source of radiation. The SI unit of physical nuclear radiation is the becquerel (Bq). A radiation source with an activity of one becquerel has one disintegration per second. An older unit of physical nuclear radiation which is still widely used is the curie (Ci); one curie is 3.7 x 10+10 Bq. Since the curie is a relatively large unit, its subdivisions of millicurie, microcurie, and picocurie are often encountered. Biological radiation units measure the effect of nuclear radiation on living tissue. The SI unit of biological radiation effect is the gray. One gray corresponds to the transfer of one joule of energy to one kilogram of living tissue. The older unit of rad (rad or D [= 10 mSv]) is exactly 0.01 gray and is now obsolete. However, the older unit of roentgen (R) is still in common use. The roentgen was originally devised as a measurement unit for use with Xrays or gamma rays, and is that quantity of radiation which generates 2.1 x 10+9 ion pairs/cm3 of dry air or 1.8 x 10+12 ion pairs/g tissue. One roentgen is 0.0096 Gy or very nearly one rad.[one rad = 0.01 gray = 10 mSv] one roentgen of gamma = 0.0096 gray = one rem of any other radiation . A oneroentgen dose of alpha radiation does not produce the same effect as does a oneroentgen dose of gamma radiation. For this reason, the rem was devised as a unit to measure the additive effects of different types of radiation, especially lowlevel radiation, for those who work with radioactive materials. The rem, or radiation equivalent in man, is the dose of any type of
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radiation which in man has the same health effect as one roentgen of Xray or gamma radiation. The rem is the most common unit used to measure health effects of radiation.
7. Effects of different dosage levels .
(a) Dose 0 to 25 rem . No detectable clinical effect in humans.
(b) Dose 25 to 100 rem . Slight shortterm reduction in number of some types of blood cells and disabling sickness not common.
(c) Dose 100 to 200 rem . Nausea and fatigue; vomiting if dose is greater than 125 rem; longerterm reduction in number of some types of blood cells.
(d) Dose 200 to 300 rem . Nausea and vomiting first day of exposure; then up to a twoweek latent period followed by appetite loss, general malaise, sore throat, pallor, diarrhea, and moderate emaciation. Recovery in about three months unless complicated by infection or injury.
(e) Dose 300 to 600 rem . Nausea, vomiting, and diarrhea in first few hours; then up to a oneweek latent period followed by loss of appetite, fever, and general malaise in the second week, followed by bleeding, inflammation of mouth and throat, diarrhea, and emaciation. Some deaths in two to six weeks. Eventual death for 50% if exposure is above 450 rem; others recover in about six months.
(f) Dose over 600 rem . Nausea, vomiting, and diarrhea in the first few hours, followed by rapid emaciation and death as early as the second week. Eventual death of nearly 100%.One roentgen corresponds to about 1.8 x 10+12/6.023 x 10+23 = 3 x 1012 moles of ion pairs.
8. Rads versus Rems . The potential lethality of radiation that a person receives also depends on the amount of energy that is absorbed by a body. Measuring this is fairly straightforward. Historically, we have measured this in a unit called the rad, which is equal to 100 ergs of energy absorbed by 1 gram of tissue. The more modern unit of absorbed radiation is the gray, which is equivalent to 100 rads. It is important to note that these units are the amount of energy absorbed per mass of tissue, and not the total amount of energy to which a body might be exposed. Measuring the amount of potential biological damage, though, requires
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merging this information about the amount of energy absorbed with the knowledge of how well the different types of radiation ionize material. This leads us to what we call an equivalent dosage. Since alpha particles are more readily absorbed by biological material than gamma rays, a smaller energy dosage of alpha hitting a sample of biological material will produce the same effect as a much larger amount of gamma radiation.
9. The equivalent dosage is measured in units called Rems (Roentgen Equivalent Man) and is equal to the absorbed dosage (in rads) times a quality factor, i.e: Equivalent Dose (in rems) = absorbed dose (in rads) x quality factor
This quality factor depends upon what type of radiation it is. The table below lists some of these for commons forms of radiation:
Radiation Type Quality FactorGamma and Beta 1Low energy neutrons and protons 5Alpha, high energy neutrons and protons 1020
Appendix B
(Refers to para 14 at page 14)
IN MAINTENANCE PHILOSOPHY
1. Onboard Repair/Maintenance. Onboard repair shall be to replacement at PCB/ Modules (LRU) level. Routine maintenance and serviceability check/terminal performance checks would also be undertaken by ships staff as part of 1st line maintenance.
2. Second Level Repair/Maintenance. Second level repair/maintenance of the system would normally be undertaken by shorebased unit (Dockyard) and will be resorted to when:
(a) Second level maintenance involving higher skills and /or elaborate set ups are required.
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(b) Periodic parameter checks and record of performance is to be undertaken as part of STW/HATs or after major components/ sub units of the system have been replaced.
3. Third/Fourth Level Repair/Maintenance. Third / fourth level repair / maintenance would include following:
(a) PCB/module repairs down to component level.
(b) Repairs/overhaul/refurbishing and testing of major assemblies/ complete system.
(c) Setting to work, testing and tuning onboard ships after major repairs/overhauls.
(d) Repair and calibration of BITE and other test equipment.
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