GPR 8710.7.pdf

DIRECTIVE NO. GPR 8710.7C APPROVED BY Signature: Original Signed By EFFECTIVE DATE: July 27, 2020 NAME: Eric K. Isaac EXPIRATION DATE: July 27, 2025 TITLE: Director, Safety and Mission Assurance

CHECK THE GSFC DIRECTIVES MANAGEMENT SYSTEM AT

http://gdms.gsfc.nasa.govTO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE.

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Goddard Procedural Requirements (GPR)

COMPLIANCE IS MANDATORY

Responsible Office: Code 360 / Safety Division Title: Cryogenic Safety

PREFACE

P.1 PURPOSE

This directive establishes requirements for minimizing cryogenic hazards to personnel, hardware, and facilities at the Goddard Space Flight Center (GSFC). It also describes the measures implemented by GSFC to assess and control the hazards associated with cryogenic systems, such as over-pressurization, frostbite, and potential oxygen-deficient areas.

P.2 APPLICABILITY

a. This directive applies to all GSFC personnel, facilities, and activities at all permanent and temporary sites. This directive also applies to all GSFC tenant organizations, contractors, commercial operations, grantees, clubs, and other persons operating on GSFC property as required by law and as directed by contractual, grant, and agreement documents.

b. In this directive, all document citations are assumed to be the latest version unless otherwise noted.

c. In this directive, all mandatory actions (i.e., requirements) are denoted by statements containing the term “shall.” The terms “may” or “can” denote discretionary privilege or permission; “should” denotes a good practice and is recommended but not required; “will” denotes expected outcome; and “are/is” denotes descriptive material.

P.3 AUTHORITIES

a. National Aeronautics and Space Act, 51 U.S.C. § 20113(a).

P.4 APPLICABLE DOCUMENTS AND FORMS

a. NPD 8710.5, Policy for Pressure Vessels and Pressurized Systems

b. NPR 8715.3, NASA General Safety Program Requirements

c. NPR 1441.1, NASA Records Management Program Requirements

d. GID 3410.0, Goddard Workforce Competence Policy

e. GPR 1700.1, Occupational Safety Program at Goddard Space Flight Center

f. GPR 8621.4, GSFC Mishap/Close Call Preparation and Response

g. GPR 8710.3, Certification and Recertification of Ground-Based Pressure Vessels and Pressurized

Systems http://gdms.gsfc.nasa.gov/gdmsnew/home.jsp http://gdms.gsfc.nasa.gov/gdmsnew/home.jsp

DIRECTIVE NO. GPR 8710.7C Page 2 of 20 EFFECTIVE DATE: July 27, 2020 EXPIRATION DATE: July 27, 2025

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h. GPR-8730.1, Metrology: Control of Measuring and Test Equipment

i. NASA-STD-8719.17, NASA Requirements for Ground-Based Pressure Vessels and Pressurized

Systems (PV/S)

j. ANSI Z87.1: Occupational and Educational Eye and Face Protection Devices

k. ANSI Z535.2: Environmental and Facility Safety Signs

l. ASTM G63: Standard Guide for Evaluating Nonmetallic Materials for Oxygen Service

m. ASTM G88: Standard Guide for Designing Systems for Oxygen Service

n. ASTM G93: Standard Practices for Cleaning Methods and Cleanliness Levels for Material and

Equipment used in Oxygen Enriched Environments

o. ASTM G94, Standard Guide for Evaluating Metals for Oxygen Service

p. ASTM MNL36, Safe Use of Oxygen and Oxygen Systems: Handbook for Design, Operation, and

Maintenance

q. CGA Pamphlet G-4.1, Cleaning Equipment for Oxygen Service

r. CGA Pamphlet P-1, Safe Handling of Compressed Gases in Containers

s. CGA P-12, Safe Handling of Cryogenic Liquids

t. CGA P-30, Portable Cryogenic Liquid Containers - Use, Care and Disposal

u. CGA P-39, Guidelines for Oxygen-Rich Atmospheres

v. CGA P-69, Guidelines for Emergency Response to Cryogenic Liquid Releases

w. CGA SB-2, Oxygen-Deficient Atmospheres

x. NFPA 55, Compressed Gases and Cryogenic Fluids Code

y. OSHA 29 CFR 1910.104, Oxygen, Bulk Oxygen Systems

z. GSFC 8-6, GSFC On the Job Training (OJT)

aa. GSFC 23-81, Cryogenic Systems Hazards Analysis Checklist

bb. GSFC 23-82, Personnel Certification Levels for use of Stored Cryogens

cc. IEST-STD-CC1246, Product Cleanliness Levels – Applications, Requirements, and Determination

P.5 CANCELLATION

GPR 8710.7B, Cryogenic Safety

P.6 SAFETY

None

P.7 TRAINING

Training for cryogenic personnel is covered in Section 5.0.

P.8 RECORDS

Documentation of training and certification is the responsibility of the appropriate management organization. See GID 3410.0.

DIRECTIVE NO. GPR 8710.7C Page 3 of 20

Record Title Record Custodian Retention Liquid Nitrogen filling station user Training Records

Responsible Branch Head *NRRS 3/33C Destroy 5 years after separation of employee or when no longer needed.

Record of Cryogenic Safety Committee (CSC) Minutes and Attendance

CSC Chair *NRRS 1/14B1(a) Permanent. Retire to FRC when 2 years old. Transfer to National Archive and Records Management (NARA) when 20 years old.

CSC Cryogenic Safety Audit Records

Cryogenic Safety Engineer

(CSE)

*NRRS 1/14B1(b) Destroy when 3 years old or when no longer needed for reference, whichever is sooner.

Liquid Oxygen Personnel Training Records

Responsible Branch Head *NRRS 3/33C

GSFC 23-81 Cryogenic Systems Hazards Analysis Checklists

Project Supervisor *NRRS 1/14B1(b)

GSFC 23-82 Personnel Certification Levels for use of Stored Cryogens

Project Supervisor *NRRS 3/33C

Oxygen Deficient Atmosphere Training

Office of Human Capital Management (OHCM)

*NRRS 3/33C

Basic Cryogenic Hazards OHCM *NRRS 3/33C Cryogenic Design, Operation, and Construction Training

OHCM *NRRS 3/33C

On the Job Training Supervisor *NRRS 3/33C System/Equipment Maintenance Records

Project Supervisor *NRRS 1/14B1(b)

Monthly Inspection Records Project Supervisor *NRRS 1/14B1(b) Inspection Records System Owner *NRRS 1/14B1(b) Oxygen Sensor Calibration Records

Equipment Owner *NRRS 1/124. Transfer to Federal Records Center (FRC) when 3 years old. Destroy 10 years after transfer.

*NRRS – NASA Records Retention Schedules (NRRS 1441.1)

P.9 MEASUREMENT/VERIFICATION

The results of annual/periodic system reviews show substantial compliance with this GPR. Systems not in full compliance, have documented low-risk paths to full compliance.

http://nodis3.gsfc.nasa.gov/library/lib_docs.cfm?range=1___

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PROCEDURES

1. Roles and Responsibilities

1.1 Goddard Safety Committee (GSC) is responsible for the overall direction of GSFC’s Health and

Safety Program, including the Cryogenic Safety Program.

1.2 Chief, Safety Division will:

a. Designate the Chair of the Cryogenic Safety Committee (CSC);

b. Provide notification to the Agency Occupational Health Officer (OHO) regarding any cryogenic or low oxygen atmosphere injury or incident; and

c. Appoint and maintain the position of Cryogenic Safety Engineer (CSE).

1.3 Branch Heads/Supervisors shall:

a. Designate custodians of cryogenic systems and Oxygen Deficiency Hazard (ODH) designated areas;

b. Maintain a record of individuals trained on any cryogenic system;

c. Identify persons capable of providing the On the Job Training (OJT) specified in this document and, upon request of the CSC or CSE, provide justification that said persons are qualified to administer this training;

d. Ensure that all facilities and equipment are properly maintained;

e. Ensure that applicable employees are trained and knowledgeable in the hazards associated with cryogenic systems and potential oxygen deficiency;

f. Ensure that cryogenic safety requirements are in place on systems used by their organization;

g. Ensure potential ODH areas are assessed and classified by the Industrial Hygiene office;

h. Ensure that safety signs required by this directive are posted by the user organization under the guidance of the Industrial Hygiene office; and

i. Ensure that oxygen monitors within their jurisdiction are maintained and tested per manufacturer’s recommendations and calibrated as defined in GPR 8730.1.

j. Consult their CSC representative for interpretation and guidance on this GPR, agency policy, and national consensus standards.

1.4 CSC – The CSC will consist of representatives identified by their directorates as having appropriate areas of expertise. The CSC is responsible to the GSC and will:

a. Oversee implementation and maintenance of GSFC’s Cryogenic Safety Program, which includes the ODH program;

b. Meet quarterly, or as necessary, to accomplish its responsibilities;

c. Ensure that the cryogenic safety program at GSFC minimizes the health and safety risks to government and contractor employees and the public as well as any risks to NASA hardware and facilities;

d. Inform management of the risks associated with any cryogenic operation where the requirements of this GPR are not met, if unsafe practices are observed, or if equipment shows unexpected or

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08/16 anomalous performance. If necessary, for GSFC work stoppage policy, reference GPR 1700.1 section 1.0.

e. Ensure that GSFC policies, Federal regulations, applicable national consensus standards, and sound practices are met;

f. In cooperation with the Pressure Systems Manager, review and approve all new, altered or modified cryogenic systems prior to their first operation for adherence to the requirements described in section 3.1 and, if necessary, prescribe conditions and requirements to minimize cryogenic hazards.

The CSC may designate a person or persons to give approval for routine requests;

g. Review all cryogenic areas prior to startup of operations and after each alteration or modification.

For remote locations, the area supervisor may collaborate with the CSC for performing these reviews;

h. Specify posting and entry requirements for designated ODH areas;

i. Maintain the cryogenic working group charter;

j. In cooperation with the Pressure Systems Manager, review the inventory of cryogenic systems.

k. Assist center personnel with the interpretation of this GPR, agency policy, and national consensus standards.

1.5 The Chair of the CSC will:

a. Convene the CSC as necessary to meet the requirements of this GPR;

b. Maintain a record of CSC attendance and meeting minutes; and

c. Act on behalf of the CSC, as necessary. All actions taken on behalf of the CSC will be reported to the CSC at the next meeting.

1.6 The CSE will:

a. Audit cryogenic safety records and evaluate compliance with CSC requirements;

b. Maintain appropriate records of inspections and evaluations;

c. Require the immediate cessation of operations of any cryogenic systems or ODH area determined to pose an imminent threat to personnel safety;

d. Conduct periodic inspections of cryogenic or ODH areas for compliance to this GPR and to

Industry standards for cryogenic safety; and

e. Collaborate with the Pressure Systems Manager to ensure an inventory of all cryogenic is maintained.

1.7 Users/Custodians – Users are those who work directly with cryogens or cryogenic systems.

Custodians are those who have primary responsibility for a cryogenic system:

a. All users of cryogens are required to take the cryogenic training described in this document and follow the directives and instructions described herein. Alternative cryogenic training may be acceptable upon review by the CSC and management.

b. Custodians are responsible to ensure that cryogenic safety hazards are reduced to as low a level as is reasonably achievable. This includes ensuring that a safety analysis and review of their systems is performed prior to first operation as described herein.

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c. Custodians are responsible to ensure modifications or alterations to any previously reviewed system are reviewed by the CSC.

d. Custodians are responsible to ensure that all safety documentation (such as hazardous procedures, job hazard analysis, etc.) is updated and consistent with the operating system it is associated with, and be prepared to demonstrate this to the CSC, or CSE upon request.

1.8 Ancillary Personnel – Ancillary personnel work in the immediate vicinity of cryogens or cryogenic systems but do not work directly with them. They may also be personnel required to enter ODH designated areas as part of their normal work duties. Examples are security or custodial workers.

Supervisors must require ancillary personnel to take the required ODH and/or cryogenic training described in this document and follow the directives and instructions therein.

1.9 Contractor – Contractors operating at GSFC facilities are subject to all provisions of the GSFC Cryogenic Safety Program. Contractors may be exempt from GSFC specific training requirements if their cryogenic training program is reviewed and accepted by the CSC. All contractor exemptions are required to be coordinated and approved by the Contracting Officer responsible for a specific contract.

2. Requirements for Fabricated, Purchased, or Loaned Cryogenic Equipment

Branch/Supervisor are responsible for ensuring items below are correct.

2.1 Commercial Off the Shelf (COTS) Products shall:

a. Be clearly designated for use at cryogenic temperatures, be fluid compatible with the intended cryogen, and (when applicable) contain a safety relief system.

b. Be used in strict accordance with manufacturer’s specifications.

c. Be tracked per the Pressure Vessel and System (PVS) requirements, in accordance with NPD 8710.5, NASA-STD-8719.17, and GPR 8710.3 for pressurized systems.

2.2 Custom Fabricated Equipment shall:

a. Be designed and constructed in accordance with current national consensus standards, good cryogenic safety practices and made as safe as practicably possible.

Note: Contact the Cryogenic Safety Committee (CSC) and Pressure Systems Manager for design guidance and applicability of national consensus standards. For access to national consensus standards, visit the NASA Technical Standards System website at https://standards.nasa.gov/.

b. Conform to PVS requirements documented in NPD 8710.5, NASA-STD-8719.17, and GPR 8710.3 for pressurized systems.

c. Have all specifications reviewed by the CSE (or designee),

d. Have all operating cryogenic systems be reviewed by the CSC as set forth in this document.

The responsible experimenter is required to supply any applicable safety documentation described in the CSC review section (3.1).

https://standards.nasa.gov/

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2.3 Legacy Systems

For pressurized legacy systems, reference NASA-STD-8719.17, NASA Requirements for Ground-Based Pressure Vessels and Pressurized Systems (PV/S) section 4.7. Consult any design changes with the Pressure Systems Manager and the CSC.

2.4 Loaned Cryogenic Equipment

When equipment is on loan from another branch/organization, the safety responsibility lies in the branch/organization using the borrowed equipment. This includes ensuring that a safety peer review process (see Section 3.0) is done if any substantial changes are made to the initial system safety documentation. The branch/organization lending the equipment is obligated to provide any necessary instruction and documentation to support safe operation of that equipment. This includes but is not necessarily limited to: equipment documentation, operating procedures, maintenance requirements, and

OJT.

3. CSC System/Equipment Reviews

To verify compliance with GSFC cryogenic safety requirements, cryogenic equipment and systems must be reviewed by the CSC and the Pressure Systems Manager. Exception from review may be determined by the CSC or the Pressure Systems Manager.

Any documentation listed in this section as required for CSC review will be supplied by the owner or operator of the system/equipment.

Cryo-pumps in which the cold head has its own overpressure protection when physically isolated from the inside of the vacuum chamber are exempt from this requirement.

3.1 CSC Review Documentation

At least 2 weeks prior to first operation of any cryogenic system, the following applicable documents must be obtained and supplied to the CSC (upon request) as part of the system/equipment review process:

a. Schematics and piping and instrumentation flow diagrams providing a complete and accurate functional description of the system. For systems requiring PVS certification, reference GPR 8710.3 section 2.4;

b. Sufficient documentation to show that the components and materials used are appropriate and compatible for cryogenic fluids and temperatures;

c. Operating procedures;

d. Operator training;

e. A list of all valves and ports which have the potential of discharging cold gas or cryogens to the atmosphere (the possibility of such a discharge causing personnel injury should be evaluated);

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f. A description of any maintenance requirements;

g. Analysis demonstrating the adequacy of pressure relief valve sizing under worst-case failure conditions, and

h. Completed ODH analysis evaluating the risk presented under credible worst-case failure conditions.

See Section 8.1.

The CSC may request additional documentation unique or specific to any cryogenic system under review. Contact the CSC for guidance and clarification on the applicability of this section.

3.2 CSC Review Process

The chair of the CSC will:

a. Convene the group including the Pressure Systems Manager and meet with the responsible system operator after reviewing the safety documentation package.

b. Conduct a walkthrough of the cryogenic test setup prior to operations to ensure safety requirements are met

c. Review all ODH areas upon initial designation to assist the owner of the space in defining mitigation or control strategies to reduce the overall hazard in the space.

The user/custodian of the system shall:

a. Complete a hazard analysis checklist form GSFC 23-81 prior to system operation.

b. Notify the CSC of any operating system configuration change that significantly alters the safety documentation for review and approval.

Safety personnel will perform periodic safety survey, occurring no less than annually, of operating cryogenic systems to ensure that safety documentation is consistent with the operating system with which it is associated.

4. Personal Protective Equipment (PPE)

Appropriate PPE is required when handling, transferring, or working with cryogenic fluids. If personnel are within an established exclusion zone, as determined by Project or Occupational Safety, PPE is required regardless of activity. PPE should be selected based on the specific cryogenic material to be used to prevent material compatibility issues. PPE shall include:

a. Eye protection – Safety goggles are required when handling or transferring fluids which might result in exposure to cold boil off gases such as an open system. In addition, a full-face shield is required to be worn if a high potential of spraying or splashing may occur. Safety glasses with side shields are acceptable when working with closed cryogenic systems. Eye protection is required to be in conformance with ANSI Z87.1;

b. Hand protection - Insulated gloves designed for use with cryogenic fluids are required when working with cryogens.

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c. Clothing - Nonabsorbent shirts and pants that minimize skin exposure are acceptable. Lab coats or aprons are recommended, and

d. Footwear - Nonabsorbent footwear is required. Sandals or open-toed shoes are not permitted.

5. Cryogenic Training for Personnel

5.1 Training Requirements

All personnel working with cryogenic systems need to be thoroughly familiar with the hazards involved and be familiar with all emergency measures that may be required in the event of an accident.

Reference Table 1 for training requirements at GSFC. Alternative cryogenic training may be acceptable upon review by the CSC and management.

Table 1. Training Requirements

ODH* BASIC

HAZARDS**

DESIGN,

CONSTRUCTION

AND

OPERATIONS***

OJT

Entry into ODH Designated Areas √ Working with or around cryogens, basic use of Liquid Nitrogen (LN2), Liquid Argon (LAr), or Liquid Helium (LHe), or operation of a cryogenic system

Cryogenic system designers, liquid oxygen users, hands-on operators of sub-atmospheric LHe systems

LN2 Fill Station Responsible Trainers √ √ √ Refresher Frequency 3 years 3 years 3 years As determined by

System Owner

* GSFC-SH-ODH, GSFC-Oxygen Deficiency Hazards ** GSFC-SH-BCS, GSFC-Basic Cryogenic Safety *** GSFC-SH-CSDCO, GSFC-Cryogenic Safety: Design, Construction and Operations

* and ** WFF-SH-CST GSFC-Cryogenics and Oxygen Deficiency Hazard Basic Safety Training (WFF)

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5.2 User OJT Requirements

Prior to operation on any cryogenic systems, users are required to be instructed in the following:

a. Description of the equipment;

b. Operating procedures including PPE requirements;

c. Maintenance schedule and procedures;

d. Hazards specific to a the particular test setup;

e. Location of ODH alarms and routes of egress in the event of an alarm; and

f. Procedures for reporting of incidents.

It is the responsibility of the branch/organization head to ensure that persons administering OJT are duly qualified. Requests for qualifications for OJT trainers may be made by the CSE or CSC. Form GSFC 23-82, Personnel Certification Levels for use of Stored Cryogens, may be used as a model for qualifying trainers. OJT group qualification is possible on a series of systems if they are similar in hazards, design and operations.

On the Job Training shall:

a. Be documented, and records kept by the respective supervisor.

b. Include documentation of: 1) content of training, 2) completion date(s), 3) name of trainer, and 4) supervisor verification.

The CSE or CSC may request to review user qualification documentation for any operating cryogenic system. Form GSFC 8-6 GSFC On The Job Training (OJT), may also be used to document personnel OJT. The form is found at the NASA Electronic Form website https://nef.nasa.gov/.

5.3 User Training for Liquid Nitrogen Filling Stations

This section is applicable to filling of Department of Transportation (DOT) 4L Containers.

All users of liquid nitrogen filling stations shall be trained on a specific station. The training process requires the following:

a. A review of the fill procedure, including applicable PPE requirements;

b. A description of the cryogenic container’s inspection process;

c. An explanation of the emergency procedures, and

d. A demonstration of the filling process by the user.

Users of liquid nitrogen filling stations need to be retrained if a modification is made to the filling station which affects its operation or potential hazards.

All stations are required to have the name of responsible trainers and an operating procedure posted or available. It is the responsibility of the branch or organization owning the filling station to designate a https://nef.nasa.gov/

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08/16 responsible person and to maintain a record of trained users for each station. The responsible person for a LN2 filling station must be the primary trainer for new users at that station, and needs to ensure that safety postings are maintained, and an up-to-date operating procedure is available.

6. System Maintenance and Inspection

The party responsible for any cryogenic system shall:

a. Perform maintenance per equipment manufacturer or applicable NASA requirements;

b. Document the schedule and nature of the maintenance. Maintenance documentation must be kept with the responsible organization; and

c. Perform periodic inspections for unusual or excessive ice buildup, which can potentially block relief paths or may be a sign of a compromised insulating vacuum.

Cryogenic systems and equipment are required to be inspected by the operator prior to and during system operations and after system shutdown. Inspection is required after any incident which might affect the integrity and safety of an item of cryogenic equipment.

The party responsible must ensure that relief devices installed on NASA owned cryogenic DOT containers are documented by the center PVS process, and the relief device test date is not expired. If the test date is expired, the owner or user should not fill the container until the relief device is properly tested or replaced. Once the new relief device is installed and the Pressure Systems Manager is contacted, the container may be returned to service. (This does not apply to containers that are leased. Leased containers are the responsibility of the leasing company and GSFC does not perform any maintenance on these containers. In addition, GSFC employees should not be filling leased containers).

Reference GPR 8710.3 Certification and Recertification of Ground-Based Pressure Vessels and Pressurized Systems, and NASA-STD-8719.17 NASA Requirements for Ground-Based Pressure Vessels and Pressurized Systems (PVS).

7. Liquid Oxygen Safety

Because of the unique hazards associated with liquid oxygen special precautions must be taken when designing and operating systems which utilize liquid oxygen. System component design, configuration management, and selection of appropriate PPE are critical steps that should be thoroughly researched.

7.1 Applicable Standards

7.1.1 Design Standards

Liquid oxygen systems built, designed, or operated at GSFC shall conform to either:

ASTM MNL36: Safe Use of Oxygen and Oxygen Systems: Handbook for Design, Operation and Maintenance or all applicable of the following:

a. ASTM G88: Standard Guide for Designing Systems for Oxygen Service;

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b. ASTM G63: Standard Guide for Evaluating Nonmetallic Materials for Oxygen Service;

c. ASTM G94: Standard Guide for Evaluating Metals for Oxygen Service

7.1.2 Cleanliness Standards

Liquid Oxygen systems or components shall be cleaned in accordance with one of the following:

a. ASTM G93: Standard Practices for Cleaning Methods and Cleanliness Levels for Material and

Equipment Used in Oxygen Enriched Environments,

b. Compressed Gas Association’s (CGA’s) Pamphlet G-4.1: Cleaning Equipment for Oxygen Service,

c. IEST-STD-CC1246 Product Cleanliness Levels – Applications, Requirements, and Determination

(cleanliness level must be equal or better than, a. or b. above).

Note: Ground Support Equipment (GSE) cleaned in accordance with NASA documents KSC-C-123 Specification for Surface Cleanliness of Ground Support Equipment Fluid Systems and MSFC-SPEC- 164 Specification for Cleanliness of Components for Use in Oxygen, Fuel, and Pneumatic Systems, may be used upon review from the CSC.

7.2 Liquid Oxygen Storage

7.2.1 Fixed or permanent liquid oxygen storage shall be in accordance with NFPA 55 Compressed

Gases & Cryogenic Fluids Code, and OSHA 29 CFR 1910.104.

7.2.2 Portable liquid oxygen container storage areas shall adhere to the following:

a. Be separated from flammables and combustibles by a minimum of 20 feet (NFPA 55). Distances may be reduced based on additional compliance with NFPA 55. Consult the GSFC safety division for guidance.

b. Be posted with "No Smoking" and "No Open Flames" signs within 25 ft (NFPA 55)

c. Be prohibited from having ignition sources within 25 feet of any oxygen container or purge system

(CGA P-12)

d. Have fixed monitoring for high oxygen levels when a credible oxygen enrichment hazard exits.

These monitors alarm at 23.5% oxygen by volume (CGA P-39). Consult the Center Industrial Hygiene office for further assistance and risk management.

Note: A typical 160-liter liquid oxygen container is equivalent to approximately 5000 cubic feet of gas.

7.3 The responsible party must require personnel to be trained and familiar with the following:

a. The list of OJT-required topics described in section 5.2

b. An explanation of oxygen material compatibility issues

c. Combustion/flammability issues associated with liquid oxygen storage areas

d. A description of the hazards of high flow velocities in oxygen systems

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e. A description of the cleanliness requirements for oxygen systems

f. Proper procedures for handling leaks and spills

g. Recognition of normal operations and of signs and symptoms that indicate deviations from such operations

h. Knowledge of the nature and properties of oxygen in both the liquid and gaseous phases.

Training records for liquid oxygen purchasers and users must be kept by the responsible supervisor or branch head.

7.4 CSC Review process for liquid oxygen systems need to include:

a. A list of required safety documentation described in section 3.1

b. Identification of designated containers or bulk liquid oxygen storage areas

c. A plan for mitigation of combustion hazards

d. Analysis of material compatibility with Oxygen (O2)

e. Cleanliness procedures;

f. Analysis of piping design for minimization of flow velocities

g. Electrostatic discharge risk mitigation/reduction plan

i. Procedures for implementing a buddy system when handling liquid oxygen.

j. Assessment evaluating the risk presented under worst-case failure conditions and Oxygen-enriched environment.

Any system using liquid oxygen is required to be reviewed by the CSC and the Pressure Systems Manager.

8.0 Oxygen Deficiency Hazard (ODH)

8.1 ODH Risk Assessment

An ODH assessment shall be conducted whenever an area containing enough displacing gas to pose a potential oxygen deficiency is established or modified, and wherever cryogens are used, stored, or dispensed. The goal of the ODH risk assessment is to estimate the increase in the rate at which fatalities will occur in a given area so that appropriate controls can be established to reduce the hazard. To have an ODH risk assessment completed contact the Center Industrial Hygiene office. The Safety Division designates the proper procedure for assessing the ODH hazard of a given area as well as the proper ODH alarm response procedure. See Table 2 for the ODH classification requirements.

Personnel shall not enter or occupy an area where the oxygen level is less than 19.5% by volume.

Reference OSHA 1915.12 (a) and Compressed Gas Association Safety Bulletin CGA SB-2 Oxygen- Deficient Atmospheres.

8.2 ODH Signage

Areas determined to have a potential for oxygen deficiency hazard shall:

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a. Be identified by signage at all entrances, see appendix C for signage. Supervisors are responsible for ensuring that work areas signage reflect the current ODH hazard level.

b. Be posted and de-posted if the hazard is temporary and an ODH analysis considering the change in potential displacing gas has been made.

c. Have ODH alarm response policy posted adjacent to any fixed ODH alarm sensor or at the entrance to any ODH designated areas while the ODH threat is present.

8.3 Visitor Requirements

Visitors or temporary workers may enter “Caution” (ODH 0) or “Warning” (ODH 1) areas only after completing ODH training. If visitors or temporary workers are not trained, then they must be escorted by trained personnel while inside the ODH areas.

8.4 Oxygen Monitoring

8.4.1 Fixed Oxygen Monitors shall:

a. Activate warning system at an oxygen concentration of 19.5% and have an audible alarm and flashing strobe light. The audible alarm and strobe light must be different from other alarms in the immediate area, such as fire alarms.

• Note: A flashing strobe light blue in color is recommended

b. Be installed at a location with consideration of the displacing gas buoyancy.

c. Not be disabled, except by qualified personnel under the authority of the area supervisor.

8.4.2 Portable Oxygen Monitors shall:

a. Be readily accessible to ODH designated areas. Consult area supervisors for assistance.

b. Activate its alarm at a set point of 19.5% oxygen. The organization issuing personal oxygen monitors is responsible for compliance with this requirement.

c. Not be permanently used in lieu of a required fixed oxygen monitor.

8.4.3 Maintenance and Calibration of Stationary and Portable Oxygen Monitors.

8.4.3.1 Oxygen Monitors shall:

a. Be calibrated in accordance with manufacturer’s direction. Reference GPR 8730.1 Metrology:

Control of Measuring and Test Equipment.

b. Be verified at least annually using a known sample gas, to verify the alarm set point of 19.5 %.

c. Have calibration records maintained by the organization that owns the equipment.

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Table 2. ODH Requirements

ODH

Classification

Description (Hours worked per fatality)

Door Posting Required

Portable O2 Monitor

Fixed O2 Monitor & Buddy System

Re-Entry Procedures Required

No Classification

>1 billion No N/A N/A N/A

Caution, ODH 0

>10 million Yes Recommended Recommended No

Warning, ODH 1

<10 million Yes Recommended Required* Yes

*If approved by the cryogenic safety engineer, branch head and industrial hygienist, a portable oxygen monitor may be used in place of a fixed monitoring system on a temporary basis. For information on Buddy System, reference GPR 1700.1, Occupational Safety Program at Goddard Space Flight Center.

9.0 Liquid Helium (LHe)

9.1 Liquid Helium Systems shall:

a. Be designed and operated to prevent backflow of air and other gases into the system. Backflow is a major safety hazard associated with liquid helium because ice obstruction may form in safety relief valves, vent lines, and process piping creating over-pressurization and leading to container rupture.

b. Be operated by trained personnel. It is the supervisor’s responsibility to ensure that personnel operating liquid helium systems are trained and understand the hazards associated with the system.

DIRECTIVE NO. GPR 8710.7C Page 16 of 20

Appendix A – Definitions

A.1 Backflow – Backflow is the diffusion or cryopumping of air or other gases into liquid helium and liquid hydrogen vessels and equipment. (reference CGA P-12) Note: Backflow can also occur on other cryogenic systems. Consult the CSC for guidance.

A.2 Cryogenic – Operating at or below -150°C, -238ºF or 123K.

A.3 Cryogenic System – An item of equipment or multiple items operating together that contain at least one component that operates at cryogenic temperature. Closed cycle refrigerators or cryocooler setups are examples of cryogenic systems.

A.4 Oxygen Deficient Atmosphere – Occupational Safety and Health Administration (OSHA) defines an oxygen deficient atmosphere as one having less than 19.5% oxygen by volume.

A.5 Qualified Personnel - Having sufficient knowledge, expertise and training required to complete a task, as deemed by the authority responsible for safe operations of the equipment with which that task is associated.

A.6 Fixed Oxygen Monitoring System - A system that has sensors affixed in a permanent manner such as in rigid conduit or mounted to a non-movable surface with a display device that does not have the ability to be freely moved while in service.

A.7 Oxygen Deficiency Hazard – Having the potential to displace enough air in a given space that the percent of oxygen would be less than 19.5% by volume.

DIRECTIVE NO. GPR 8710.7C Page 17 of 20

Appendix B – Acronyms

ANSI American National Standards Institute ASTM American Society for Testing and Materials CGA Compressed Gas Association COTS Commercial Off the Shelf CSE Cryogenic Safety Engineer CSC Cryogenic Safety Committee DOT Department of Transportation FRC Federal Records Center GPR Goddard Procedural Requirement GSC Goddard Safety Committee GSFC Goddard Space Flight Center LAr Liquid Argon LHe Liquid Helium LN2 Liquid Nitrogen NARA National Archive and Records Administration NASA National Aeronautics and Space Administration NFPA National Fire Protection Association NPD NASA Policy Directive NPR NASA Procedural Requirement NRRS NASA Records Retention Schedule ODH Oxygen Deficiency Hazard OHCM Office of Human Capital Management OHO Occupational Health Officer OJT On the Job Training OSHA Occupational Safety and Health Administration PVS Pressure Vessels and Pressurized Systems PPE Personal Protective Equipment STD Standard

DIRECTIVE NO. GPR 8710.7C Page 18 of 20

Appendix C – ODH Signs

DIRECTIVE NO. GPR 8710.7C Page 19 of 20

DIRECTIVE NO. GPR 8710.7C Page 20 of 20

CHANGE HISTORY LOG

Revision Effective Date Description of Changes

Baseline 03/04/08 Initial Release

A

11/10/10 Administratively revised to reflect new organization name and code change.

B 03/01/13 Document revised to reflect improved processes, clarify training requirements and meet internal mandates.

02/12/18 Administratively changed to reflect new organization name and code and to update the GPR template. Administratively extend for 1 year.

02/21/19 Administratively extended for 6 months from current expiration date.

C 07/27/20 Document revised to reflect improved processes, clarify training requirements and meet internal mandates.