Cold Source Cleaning Specification JS-200.000-001-REV 3.pdf

COLD SOURCE CLEANING SPECIFICATION REV. 3 JS-200.000-001

Issue Date: 11/22/2006

1. SCOPE

This specification provides guidance on required cleanliness levels of systems, components, and items procured, built, or fabricated for use in the HFIR Cold Source. The HFIR Cold Source is a forced-flow hydrogen loop being installed in HB-4 of HFIR at Oak Ridge National Laboratory in Oak Ridge, TN. This specification supersedes HFIR-CS-06-200-CLEAN, “HFIR Cold Source Cleaning Specification”. Wherever “HFIR-CS-06-CLEAN” is referenced, this specification may be used.

Exceptions to this cleaning procedure should be submitted on a standard deviation form (SEPF-0209.1) for approval by the Company.

2. ENCLOSURES

JS-200.000-001, Pages 1 - 9 Attachment A, Final Cleanliness Report for Cold Source Components & Systems, Page 1 Attachment B, Specific Cleanliness Requirements Table, Pages 1 - 3 Attachment C, Guidelines for Cleanliness During Cold Source Equipment Field Assembly and

Maintenance, Pages 1 - 5 Attachment D, Example Blue Tag, Page 1

3. MISCELLANEOUS REQUIREMENTS

For fabrications performed under contract, sections 3 - 12 and Attachments A and B of this document are requirements. Attachment C is not a requirement, unless otherwise designated in the contract.

For fabrication, installation, and maintenance performed by ORNL personnel:

• Personnel planning fabrication, installation, and maintenance activities shall consult with the System Engineer to determine appropriate cleanliness requirements,

• The System Engineer shall use Attachment C as a guideline and the balance of this document as references, and establish the appropriate cleanliness requirements,

• The Task Leader shall assure that cleanliness requirements are followed during field work.

3.1 GENERAL

3.1.1 All documentation shall be legible, accurate, reproducible, identifiable and in English.

Safety Precaution It is the responsibility of all users of this specification to review pertinent Material Safety Data Sheets (MSDSs) and materials specifications to assure safety of personnel and protection of the environment and facilities in fulfilling the requirements of this document.

3.1.2 All Cold Source parts, components, assemblies and systems used in hydrogen systems, which may be exposed to hydrogen, exposed to high vacuum, and other ancillary equipment (see Attachment B) shall be cleaned and inspected in accordance with this specification. Assembled parts, which may be damaged during cleaning operation, shall be disassembled to a level to permit cleaning.

3.1.3 Halogenated solvents shall not be used on titanium alloys.

3.1.4 Inspection aids such as lights, borescopes, mirrors, and ultraviolet lamps shall be as clean as the surface they are being utilized to check.

3.1.5 Items cleaned in accordance with this specification shall be suitable for their intended use without additional cleaning. Items which do not meet the requirements of this specification shall be subject to rejection.

3.1.6 Fabrication activities shall be conducted so as to facilitate cleaning and inspection for cleanliness and to minimize contamination during the fabrication process. Contaminants such as cutting fluids, welding slag, and other processing compounds shall be removed at intervals compatible with the fabrication or assembly operation.

3.1.7 Components shall be protected from the general shop atmosphere, or other contaminated atmospheres such as salt air or blowing dust, as much as is possible during fabrication and storage.

3.1.8 A lubricant may be employed during machining, fabricating, and assembly operations provided the lubricant does not contaminate any crevice or inaccessible area to the extent that it cannot be cleaned to the requirements of this specification. The lubricant should be removed after completion of the fabrication activity.

3.2 MARKING

3.2.1 Identification on welds should be marked in a manner that is not conducive to corroding the base metal.

3.2.2 To preclude off-gassing, no markings are allowed on surfaces subject to operation at high vacuums.

3.2.3 Marking of components, items, and pieces shall be in accordance with the applicable drawing.

4. GENERAL CLEANING REQUIREMENTS

4.1 CONTROL OF SURFACES

4.1.1 All significant surfaces shall be pre-cleaned to remove dirt, grit, scale, corrosion, grease, oil, and other foreign material prior to any final precision cleaning process. Assembled items which do not lend themselves to this type of treatment shall be pre-cleaned prior to assembly. Surface areas which are degraded during subsequent fabrication and assembly shall be re-cleaned, as required, to restore the original protective finish.

4.1.2 Materials shall be kept clean and protected from contamination and environmental degradation. Contact or contamination from materials containing copper, silver, lead, solders, mercury, thorium, bismuth, uranium, chlorine, fluorine, graphite, or other materials corrosive to aluminum, shall be avoided.

Any accidental contamination must be documented and removed using a method approved by the Company.

4.1.3 Extreme care shall be taken during fabrications to prevent contamination by foreign materials. Temporary plugs or seals shall be installed as required to keep contaminants out of a clean component during fabrication and storage activities. Due diligence shall be exercised to prevent temporary plugs and seals from being inadvertently left inside the component when shipped and to preclude the accidental loss of articles inside a component; however, external plugs shall remain in place to ensure preservation of cleanliness.

4.2 GASES

4.2.1 Nitrogen gas used for drying and testing of items cleaned per this standard shall conform to MIL-P-27401D, type I, Grade A; OR A-A-59503, type I, class 1, grade B.

4.2.2 Nitrogen gas should be filtered prior to being utilized in a Category A (see Attachment B) system. The filter elements should be made of noncalendered woven wire mesh. Sintered metal elements shall not be used. The filter element should retain 100 % of the particles greater than 150 micrometers (0.0059 inches) in diameter.

4.3 PRECISION CLEANING

Precision cleaning is performed after gross cleaning and may be accomplished by employing solvent flushing. Isopropyl or ethyl alcohol can be used to perform particulate analysis, but shall not be used as a test fluid for NVR analysis.

Cold source components generally do not require precision cleaning. If precision cleaning of a component or item is required, it should be clearly called out on the appropriate drawing.

If precision cleaning is required, the vendor or fabricator shall submit a plan which, at a minimum, describes the cleaning process for the component, verification of the cleanliness process, and how the item will be packaged and kept at an acceptable cleanliness level at least 10 working days prior to performing the cleaning operation.

Minimum cleanliness requirements will be as specified by the Company. These minimum requirements will determine the types of cleaning agents which may be utilized, and define the acceptable particulate and NVR contamination allowed after cleaning. Further information may be requested at the Company’s discretion.

4.4 ULTRASONIC CLEANING

Ultrasonic cleaning is appropriate for removal of contaminants found on materials, parts, and components used in systems requiring a visually clean level of cleanliness. If utilized, ultrasonic cleaning shall be performed in accordance with ASTM-G 131. Parts shall have been pre-cleaned to remove visible contaminants prior to being ultrasonically cleaned. Final cleanliness requirements are as listed in Attachment B.

4.5 PASSIVATION

Passivation may be utilized to clean stainless steel components. If utilized, passivation practices shall be performed in accordance with ASTM-A 380. Final cleanliness requirements are as listed in Attachment B.

5. SPECIFIC CLEANING REQUIREMENTS

5.1 Cleaning requirements for cold source components should be called out on drawings.

Drawing or specification requirements may be more stringent than those listed in Attachment B.

5.2 Components, items, and equipment should not be subjected to cleaning, drying, or verification processes which could potentially degrade or damage the component, item or equipment. The proposed cleaning process for components, items, and equipment which fall in this category should be submitted on a standard deviation request (SEPF- 0209.1) for Company approval of the alternative cleaning process.

5.3 Completion of final cleaning, drying, and moisture verification shall be documented per Attachment A.

5.4 In the event an item does not have cleaning documentation, ORNL’s Quality Services Division shall be the sole judge of the cleanliness of that item in accordance with Attachment B and, if accepted, will complete the cleanliness report. Items which have not been accepted and are determined to not meet the cleanliness requirements shall be returned to the vendor at the vendor’s expense for appropriate cleaning.

5.5 Specific cleanliness requirements are contained in Attachment B. Items being cleaned in accordance with Category A requirements and packaged in accordance with Section 8 shall have a completed “Blue Tag” attached (Attachment D).

6. DRYING

Drying ensures the moisture and dew point levels of cold source items and components are reduced as much as possible.

CAUTION

Components, items, and equipment should not be subjected to cleaning, drying, or verification processes which could potentially degrade or damage the component, item or equipment. The proposed alternate drying process for components, items, and equipment which could be damaged by this drying process should be submitted on a standard deviation request (SEPF- 0209.1) for Company approval.

6.1 Equipment with an open configuration shall be purged with nitrogen heated to at least 135 degrees C for a minimum of 30 minutes.

6.2 Effluents from components which have been cleaned with alcohol or other hydrocarbons shall be monitored for hydrocarbons. Any measurable concentration above ambient in the drying gas shall necessitate additional drying.

6.3 Equipment with intricate parts that are likely to retain moisture when dried by purging methods, shall be vacuum dried in accordance with a vacuum level and time combination listed in Table 2. The temperature of the component should be at least 43˚ C.

TABLE 2

Vacuum Level (torr) Time at Vacuum (minutes)

50 204

25 54

15 45

7. VERIFICATION

This verification method tests for moisture and can be verified after cleaning at component fabrication or at integrated system assembly. The test shall be performed as follows:

7.1 The cleaned item shall be purged with test gas. The test gas shall be nitrogen conforming to section 4.2.

7.2 The item shall be purged for a sufficient time to ensure all of the residual air and vapor have been expelled from the item.

7.3 Purge flow should be stopped for sufficient time to allow entrapped moisture to diffuse or permeate into the static gas.

7.4 Begin monitoring for moisture in the purge gas at the item’s discharge port.

7.5 Resume purge gas flow.

7.6 The dew point of the effluent gas shall be monitored by a suitable instrument, which shall be capable of detecting a level of less than 20 ppm moisture.

NOTE: Manufacturer’s directions shall be followed for operation of the specific instrument.

7.7 Effluent gas moisture content shall be 24 ppm or less (dew point = -54˚ C).

7.8 If the effluent gas moisture content exceeds the allowable limit, THEN continue purging the item periodically repeating steps 7.6 through 7.8 until the test requirement is met.

8. PACKAGING, DELIVERY, AND STORAGE

8.1 All significant surfaces or openings to significant surfaces shall be protected from contamination by sealing the surfaces or openings with coverings or plastic film and securing with tape. Contact between the adhesive backing of the tape and the body of the item shall be minimized.

8.2 Any materials known to contribute to corrosion shall not be used for packing purposes.

8.3 Protected items shall be placed in visually clean, opaque, polyethylene bags with the ends taped shut, where possible. Under normal usage, bags and tape shall not delaminate, peel, disintegrate, slough, or otherwise deteriorate in a manner that will contaminate the cleaned item.

8.4 Completed cleaned assemblies shall be placed in wooden containers for shipping.

8.5 Preservative materials shall not be used on items which have been cleaned.

8.6 Cushioning materials used to package cleaned items shall be non-flammable and non-contaminating in nature. Cushioning materials such as excelsior, shredded newspaper, and similar materials that generate large numbers of particles and fibers shall not be used.

8.7 Aluminum components shall be blanket purged with dry nitrogen gas to a nominal pressure of 25 psig OR a pressure which will not damage the item and sealed when possible prior to packaging. The seal should retain the pressure at or near the desired level for at least 60 days. Means shall be provided for periodically checking the pressure of the article.

8.8 All containers shall have appropriate caution markings applied. Special handling markings such as TOP, UP, THIS SIDE UP, GLASS, KEEP DRY, FRAGILE or DELICATE shall be placed on shipping containers, as applicable. These markings shall not interfere with or obscure other markings.

8.9 The item shall be labeled to indicate the part number, date of manufacture, facility, and the name and address of the company.

8.10 Large items shall be protected to ensure damage does not occur to the item during transportation and the packaging and cleanliness protection remains in good condition.

9. SELLER DEVIATIONS AND NONCONFORMANCES

9.1 In the event the fabricated unit does not conform to the specified requirements of this specification and an approved deviation has not been granted by the Company, a Nonconformance Report (NCR) form shall be filed with the Company for approval.

9.2 The NCR shall contain the Seller’s recommended disposition and the technical justification associated with the recommended disposition. If the recommended disposition is repair/rework, then a copy of the proposed procedure/process shall accompany the NCR.

9.3 The Company shall have the sole authority for determining the acceptability of a proposed deviation or nonconformance.

9.4 Any work performed by the Seller prior to approval of deviations or non-conformances shall be at the Seller’s risk.

10. ACRONYMS

10.1 ACS American Chemical Society

10.2 ASTM American Society for Testing and Materials

10.3 DI deionized water

10.4 DR Deviation Request (supplied by the Company)

10.5 HFIR High Flux Isotope Reactor

10.6 NVR nonvolatile residue

10.7 ORNL Oak Ridge National Laboratory

10.8 QA Quality Assurance

10.9 RRD Research Reactor Division

10.10 SNR Supplier non-conformance report (supplied by the Company)

11. DEFINITIONS

Acetone Reagent grade in accordance with the American Chemical Society specifications or technical grade in accordance ASTM-D-329.

Blanket Purge The use of pressurized gas in an enclosed environment for protecting components, piping, or vessels from contamination.

Cleaning Removal of particulate and incompatible materials from significant surfaces of components and systems

Company Oak Ridge National Laboratory

Contaminant Any material that could chemically interact or mechanically interfere with the component or system function.

Company Hold Point Stages of work that require Company approval before proceeding further. The Seller is required to notify the Company of an upcoming hold point, at least 10 working days before a hold point.

Company Witness Point Stages at which the Company chooses to witness progress before proceeding. The seller is required to notify the Company at least 10 days before a witness point.

Dew Point The temperature at which a gas becomes saturated with water vapor and condensation begins (usually atmospheric pressure).

DI Water Demineralized water with a resistance not less than 100,000 ohm-cm and a pH between 5.0 and 8.0.

Drying Reducing moisture/dew point levels by vacuum, purge, flush, or oven methods

Generally Clean Generally clean is freedom from manufacturing residue, dirt, oil, grease, processing debris, or other extraneous contamination. This level can be achieved by washing, wiping, blowing, vacuuming, brushing, or rinsing. This level should not be designated for hardware that is sensitive to contamination.

Gross Cleaning Gross cleaning is the cleaning process normally used to achieve cleanliness level visually clean

High Vacuum A pressure range of 1x10-3 torr to 1x10-8 torr

Inaccessible Unable to be viewed due to physical configuration

Incompatible Substances which have an undesirable action on components, vacuum spaces, or system gases

Isopropyl Alcohol Alcohol meeting specification TT-I-275, grade A or B OR ACS reagent grade

Mechanical Cleaning Mechanical cleaning shall be used only when contaminants generated by the method can be removed AND when physical damage to the item being cleaned shall not occur. Mechanical cleaning may be accomplished by brushing, shot peening, grit blasting, tumbling, or grinding. All loose dirt, scale, and other debris shall be completely removed from the item by vacuum cleaning, wiping, brushing, blowing, or flushing with DI water.

Moisture The residual water (liquid/gas) in components or systems, measured in parts per million (ppm) or dew point.

Non Volatile The quantifiable substance remaining after filtration and controlled Residue (NVR) evaporation of the final flushing solvent. NVR is specified in milligrams (mg) per square meter or square foot of significant surface. Since the predominant constituents of NVR are hydrocarbons; NVR and total hydrocarbon content are considered equivalent.

Particle A minute quantity of matter, metallic or non-metallic, with observable length, width, and thickness

Passivation Passivation is the process by which a corrosive-resistant layer is bonded to a stainless steel surface by submersing the surface in an acid solution.

Pickling Pickling is the chemical or electrochemical process by which surface oxides are removed from metals.

Precision Cleaning Precision cleaning is a cleaning process used to achieve cleanliness levels more stringent than visually clean.

Significant Surface All component surfaces that may come into contact with the respective service medium (hydrogen) during normal service.

Verification The process whereby one or more of the following methods is utilized for the purpose of certifying cleanliness:

1) performing visual inspections,

2) obtaining samples,

3) analyzing/testing samples,

4) reviewing inspection/test data.

Visually Clean Visually clean is the absence of all particulate and nonparticulate matter visible at a distance of 0.5 meters under a minimum of 50 foot-candle lighting with normal or corrected vision. Particulate is defined as matter of miniature size with observable length, width, and thickness. Nonparticulate is normally a film matter without definite dimension. Visually clean is commonly referred to as commercially clean.

12. REFERENCES

The following is a list of publications, codes and standards, referenced in the body of this specification and comprising a part of it. The latest edition shall apply if none is specified herein, or indicated on drawings.

12.1 ASTM-D 770 – 95 (Reapproved 1999), “Standard Specification for Isopropyl Alcohol”

12.2 ASTM-D 329 – 02, “Standard Specification for Acetone”

12.3 DLA A-A-59503, “Technical Nitrogen”

12.4 Air Force MIL-PRF-27401D, “Propellant Pressurizing Agent, Nitrogen”

12.5 ASTM-A 380 – 99, “Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems”

12.6 ASTM-G 131 – 96 (Reapproved 2002), “Standard Practice for Cleaning Materials and Components by Ultrasonic Techniques”

12.7 SEP-0209, “Deviations”

ATTACHMENT A (JS-200.000-001)

Final Cleanliness Report For Cold Source Components & Systems

REV. 3

ATT A

FINAL CLEANLINESS REPORT FOR COLD SOURCE COMPONENTS AND SYSTEMS FINAL CLEANLINESS REPORT FOR COLD SOURCE COMPONENTS AND SYSTEMS

Category of component or system: Category of component or system:

Description of component: Description of component:

Dried per section 6 (select applicable responses): Dried per section

Signature / Date Signature / Date Meets cleanliness inspection criteria: Meets cleanliness inspection criteria:

Description of cleaning process: Description of cleaning process:

Drawing Number: Drawing Number:

Purged: Temperature of gas ˚ C. Purged: Temperature of gas ˚ C.

Hydrocarbons: Ambient level ppm Hydrocarbons: Ambient level ppm (√) Test Article ppm (√) Test Article ppm

Vacuum Dried: Vacuum Level torr Vacuum Dried: Vacuum Level torr (√) Time at vacuum minutes (√) Time at vacuum minutes

Meets drying requirements: Meets drying requirements:

Signature / Date Signature / Date

6 (select applicable responses):

Verified per section 7:

Final Moisture content: ppm OR dewpoint

Meets verification requirements Signature / Date

ATTACHMENT B (JS-200.000-001) REV. 3 ATT B

Specific Cleanliness Requirements Table Page 1 of 2

Category System or Service Cleaning (beyond generally clean) Drying Moisture

Verification Cleanliness Inspection Criteria

A

Hydrogen containing lines or hydrogen component internals with significant surfaces.

Contamination should be removed by immersing, spraying, or swabbing the component with acetone and isopropyl alcohol. Items being cleaned should be slightly above room temperature.

Ultrasonic cleaning and passivation are also acceptable cleaning methods.

Required.

Drying per section 6.

Required.

Verification per section 7.

All significant surfaces that contact hydrogen require visual inspection unless the surface is inaccessible.

Surfaces shall meet the criteria of being visually clean.

Wipe all accessible surfaces with a clean lint-free, white cotton cloth OR filter paper moistened but not saturated with isopropyl alcohol. No residue should be present on the cloth or paper at the completion of the inspection process.

B

Lines, volumes exposed to high vacuums

Contamination should be removed by immersing, spraying, or swabbing the component with acetone and isopropyl alcohol. Items being cleaned should be slightly above room temperature.

Ultrasonic cleaning and passivation are also acceptable cleaning methods.

As called out in the applicable drawing, but generally not required.

Required.

Surfaces exposed to high vacuum shall be evacuated to a vacuum of 8x10-5 torr with a vacuum pump of nominal 120 l/sec or less throughput.

All high vacuum surfaces require visual inspection unless the surface is inaccessible. Surfaces shall meet the criteria of being visually clean.

The high vacuum surface is able to be pumped to the required vacuum level with a vacuum pump of the listed capacity or less capacity.

ATTACHMENT B (JS-200.000-001) REV. 3 ATT B

Specific Cleanliness Requirements Table Page 2 of 2

Category System or Service Cleaning (beyond generally clean) Drying Moisture

Verification Cleanliness Inspection Criteria

C

Vent manifold internals, lines leading to the vent manifold, stack internals, rupture disks, pressure relief valves, helium component internals.

Exterior of components in inert boundaries.

Contamination should be removed by immersing, spraying, or swabbing the component with acetone and isopropyl alcohol.

Ultrasonic cleaning and passivation are also acceptable cleaning methods.

The exterior of components in inert boundaries should be generally clean at a minimum.

As called out in the applicable drawing, but generally not required.

As called out in the applicable drawing, but generally not required.

Wipe selected surfaces with a clean lint-free, white cotton cloth OR filter paper moistened but not saturated with isopropyl alcohol. No residue should be present on the cloth or paper at the completion of the inspection process.

The exterior of components in inert boundaries should meet the criteria of generally clean.

D

Heat exchangers, pumps, internal water cooling lines.

Internals of cooling systems, piping, and heat exchangers shall be purged with DI water.

After purging, all DI water shall be removed from the system and openings into the water systems shall be capped or covered.

As called out in the applicable drawing, but generally not required.

As called out in the applicable drawing, but generally not required.

Components should be generally clean.

Purged water should be free of gross contaminants.

Excluded

Electronic components, electrical circuitry, vacuum pump internals, motor and fan internals, gas bottles.

ATTACHMENT C (JS-200.000-001)

GUIDELINES FOR CLEANLINESS DURING COLD SOURCE

EQUIPMENT FIELD ASSEMBLY AND MAINTENANCE

ATT C

1. BASIS

The Cold Source has multiple systems that have cleanliness requirements. The system cleanliness is important:

1.1 There is no “startup strainer” installed in these systems, so any foreign material will potentially cause damage or system malfunction.

1.2 For vacuum systems, the ability to pull a vacuum will be compromised by leaving material in the system. While we are not dealing with an ultra-high vacuum, cleanliness and dryness is very important. Contaminants that will off-gas making it more difficult to achieve the desired vacuum. In general, avoid all hydrocarbon contamination such as oils or cutting fluids.

1.3 For the hydrogen system, the circulators will operate up to 60,000 rpm. Any abrasive in the system at all will likely damage the circulator impellor. It is important to understand that the hydrogen will be re-used, so this means that all of the hydrogen feed and recycling system will need to be cleaned to the same level as the cryogenic system.

1.4 Particulate in the cryogenic hydrogen system can activate, causing problems with radioactivity.

1.5 For all the gas systems, the relief valves have Teflon seats and many are in locations that are difficult to maintain. The systems have flow and pressure regulators that throttle across small openings. Both are sensitive to particulate in the system. Hydrogen and helium are very small molecules, and the control valves, relief valves, and orifices are very small making them susceptible to plugging. The flow throat for the hydrogen venturi is only ¼ inch. Some of the hydrogen relief valves have safety functions, and foreign material may disable these components.

1.6 Contamination in hydrogen will change the chemical and physical properties of the hydrogen degrading the cooling capability.

1.7 Hydrogen will explode or violently react with a variety of materials, such as chlorine, lithium, benzene, bromine, and vegetable oils + catalysts.

1.8 Stainless steel can rust quite rapidly if it fails to form its protective oxide layer. This may happen when the stainless has had carbon steel forced into its surface, as by being dragged over carbon steel during installation, brushing with carbon steel, grinding with a contaminated wheel, or temporary welds to carbon steel. The carbon steel particle forms a galvanic cell, and quickly corrodes away, but may leave a pit in the stainless steel from which pitting corrosion may rapidly progress.

Another mechanism that may interrupt the passive layer is chloride contamination.

2. GENERAL REQUIREMENTS

2.1 All systems shall be controlled to prevent large and small foreign material entry. A single mouse crawling in an open system could cause a shutdown of months. A rag left in a system would have the same result. Temporary plugs or seals shall be installed as required to keep contaminants out of a clean component during maintenance and storage activities.

2.2 All gas and vent systems shall be maintained covered at all times when not in the direct control of a staff member.

2.3 Components shall be protected from contaminated atmospheres such as blowing dust as much as is possible during maintenance and installation. A clean room is not required.

2.4 Inspection aids such as lights, borescopes, mirrors, and ultraviolet lamps shall be as clean as the surface they are being utilized to check.

2.5 Wipe flat seals clean. Use only sealant or gaskets that are specified by the work package or task leader.

2.6 Do not use any sealer or grease unless specifically called out in the work package.

If O ring grease is used, then be careful to just make the surface of the O ring shiny, do not leave extra grease. Avoid touching any surface that will see vacuum with the bare hand or gloves that are not clean, a single greasy fingerprint will cause a measurable change in the ability to pull vacuum.

2.7 All rags and gloves used shall be clean and lint free.

2.8 A lubricant may be employed during machining, fabricating, and assembly operations provided the lubricant does not contaminate any crevice or inaccessible area to the extent that it cannot be cleaned to the requirements of this specification.

The lubricant shall be removed after completion of the fabrication activity.

2.9 Identification on welds should be marked in a manner that is not conducive to corroding the base metal. To preclude off-gassing, no markings are allowed on surfaces subject to operation at high vacuums. Marking of components, items, and pieces shall be in accordance with the applicable drawing.

2.10 Avoid contamination of stainless steel with carbon steel. Remove all traces of carbon steel (evidence of corrosion) from stainless steel per task leader direction.

3. INSPECTION AND REQUIRED CLEANLINESS

3.1 There is a portion of the system (the beam tube) that is exposed to primary coolant.

Cleanliness shall be in accordance with JS-31 requirements for all components that contact the reactor primary system.

3.2 All accessible surfaces that contact hydrogen, helium, nitrogen, or associated relief system shall meet the criteria of being visually clean, no obvious particulate or other contaminants. A technique that may be used is to wipe all accessible surfaces with a clean lint-free, white cotton cloth OR filter paper moistened but not saturated with isopropyl alcohol. No residue should be present on the cloth or paper at the completion of the inspection process. No standing water or other fluids are allowed to remain in the system, and the system shall be maintained as free as humid air as can be reasonably achieved.

3.3 All accessible surfaces that contact the inert gas system and associated relief system shall have no general loose contamination, and be generally clean but are not expected to meet the white cloth test noted above. No standing water or other fluids are allowed to remain in the system.

3.4 Due diligence shall be exercised to prevent temporary plugs and seals from being inadvertently left inside the component and to preclude the accidental loss of articles inside a component.

3.5 Work packages shall contain an inspection by a peer worker or task leader for cleanliness and foreign material exclusion prior to closing system.

4. CLEANING PROCESSES

The system engineer shall specify required cleaning processes. The following are general cleaning practices that may be used or modified by the system engineer as appropriate for the specific situation.

4.1 Mechanical Cleaning:

• Mechanical cleaning shall be performed in such a manner that particles will fall away from the equipment to preclude particles from entering the component.

• Where mechanical cleaning cannot be performed in a manner that particles fall away from the equipment, a vacuum hose or dirt catcher shall be employed. A vacuum hose may also be employed near the work to remove fine airborne particles.

4.2 Detergent Cleaning:

• Mix one tablespoon of Alconox, or equivalent detergent, per gallon of hot water (approximately 160ºF).

• Scrub all surfaces with bristle or nylon brush.

• Scrub all surfaces with clean hot water immediately. Do not let cleaning solution dry on the part.

• Rinse thoroughly with tap or better quality water.

• A 5% trisodium tap water or better quality water solution may be used if Alconox is not available.

4.3 Acetone and Isopropyl Alcohol Cleaning:

• Acetone and Isopropyl alcohol may be used to immerse, spray, or swab the component. Items being cleaned should be slightly above room temperature.

4.4 Ultrasonic Cleaning:

• Ultrasonic cleaning is appropriate for removal of contaminants found on materials, parts, and components used in systems requiring a visually clean level of cleanliness. Ultrasonic cleaning shall be performed in accordance with task leader instructions, using ASTM-G 131 as a guide.

4.5 Passivation:

• Passivation may be utilized to clean stainless steel components. If utilized, passivation practices shall be performed in accordance with task leader instructions, using ASTM-A 380 as a guide.

4.6 Procedure for Pipe Cleaning:

Use this process per system engineer direction when it is evident that there are contaminants inside piping of sufficient size and configuration that the process is practical.

• Pressure-wash the inside of each pipe with tap water or other clean water source.

• Attach a hook to the front face of an appropriately sized foam rubber pig.

• Slit rags and slip them over the length of the pig. The number of rags will be determined by trial and error.

• Wet rags in accordance with detergent cleaning or acetone and isopropyl alcohol cleaning sections above.

• Run a fish tape through the inside of the pipe to be cleaned and attach one end to the hook at the pig. The tape should be long enough so that one or two men have enough length to grab onto at the other end of the pipe.

• Using leather or other protective gloves, pull the pig through the pipe several times using clean rags each time until there is no visible dirt on the rags.

5. DRYING:

The system engineer shall specify required drying processes. The following are general drying practices that may be used or modified by the system engineer as appropriate for the specific situation.

All free water or other liquids must be removed and as little exposure to humid air as can be reasonably achieved. Drying processes include:

• Wipe dry with clean lint free cloth.

• Blow dry with clean dry air. Heating the part will greatly speed the removal of water that adheres to the surface.

• Purge with nitrogen. If a nitrogen purge is used for drying, purge with nitrogen while heating the part. Do not attempt to purge with heated nitrogen.

• Vacuum drying may be used for equipment with intricate parts that are likely to retain moisture when dried by purging methods, in accordance with a vacuum level and time combination per task leader instruction.

• Desiccants use shall be in accordance with drawing requirements or may be specified by task leader. Use care to assure that the desiccant is not allowed to remain in the components following assembly.

6. STORAGE AND PROTECTION OF OPEN SYSTEMS

To maintain cleanliness of cleaned and dried components, shield open systems from humid air, moisture, or foreign material intrusion. High humidity during the summer could cause problems, but during the winter there should be no problem due to the amount of moisture in the air as long as it was not condensing. Follow system engineer direction for storage and protection of open systems and components. In general, acceptable means of protection include:

• Plugs,

• Plastic such as Saran Wrap,

• Heavy duty aluminum foil,

• Polyethylene bags with the ends taped shut.

Do not use tape on a sealing surface or surface exposed to gas, because the adhesive may remain behind and cause sealing or off gas problems.

ATTACHMENT D (JS-200.000-001)

Example Blue Tag

ATT D

When hanging the blue tag, the Task Leader shall include the appropriate contact information.

The reason for this tagging is to prevent internal contamination.

The blue tag shall look like the example below:

CATEGORY "A" CLEAN

PER JS-200.000-001

DO NOT OPEN SYSTEM UNLESS

AUTHORIZED BY SYSTEM ENG / TASK LEADER

Print Name / Signature Phone:__________________ Date:___________