SNS ELECTRICAL SAFETY WORKSHOP 2004

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SNS ELECTRICAL SAFETY WORKSHOP 2004
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• SNS site primary AC description
• SNS site grounding
• SNS site secondary AC distribution
• SNS site DC and Instrumentation distribution and
  Installation
• SNS Electrical Safety Committee

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• Tennessee Valley Authority TVA supplies power via
  161kV lines to TVA HV switch yard
• Two TVA 161/13.8kV 45MVA transformers supply SNS
  13.8kV main switch house, which has a 13.8kV
  switchgear with bus A and bus B. Bus A feeding
  KL, HE, RN, RT, TA, CL substations 13.8kV/480V
  and bus B feeding KL modulator substations
  13.8kV/2.4kV. CHL is fed from bus A and B by a
  loop feeder.

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• The entire facility grounding consists of
  100'x100' mat of 4/0Cu wire exothermically
  welded. Each crossing is tied to a grounding rod.
  An additional grounding rod is added on building
  perimeter for lightning protection. (SNS
  grounding grid_) The facility has enhanced (low
  impedance) RF grounding for the klystron building
  at each klystron station. Owing the fact that the
  building lay out has not been finalized at the
  time of RF grounding being installed, the
  additional RF mat is terminated on the north wall
  of the klystron building to a grounding plate.
  (E7-01-02.PDF) Electrical distribution is
  grounded and bonded to the 100'x100' mat. 2/0Cu
  wire is run with cable tray system and along the
  beam line for grounding and bonding of equipment.
  In addition to 2/0 wire in the LINAC tunnel,
  grounding plates tied to the 100'x100' mat are
  embedded in the LINAC tunnel wall every 100'.
  Single point ground for beam diagnostic is
  provided on the north wall of the klystron
  building. Equipment racks, water carts,
  modulators, etc., will have AC service grounded
  and bonding and grounding of enclosures will be
  provided. Raceways will be bonded and grounded.
  Shielded cables will have the shields bonded and
  grounded at the equipment site (not at the beam
  line component side).
• In addition, there are three ground breaks
  provided in the ring tunnel that separate HEBT
  and RTBT from RING service building and the ring
  tunnel itself has a ground break in the north
  collimator section.
• The beam line components and supports are bonded
  and grounded (2/0Cu)

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• Secondary Power Distribution Reliability and
  Safety
• When designing any power system under the new
  Construction Design and Maintenance (CDM)
  regulations (OSHA, NEC) safety is an important
  factor. It is worth acknowledging that safety and
  reliability can conflict. This can happen when
  safety considerations require the introduction of
  additional complexity, such as the provision of
  safety interlocks, which reduces reliability.
• Safety must always take precedence and additional
  steps will be required to maintain the required
  reliability.

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• Secondary AC distribution 480/208V to the
  accelerator equipment and facility equipment is
  strictly by NEC.
• SNS project has chosen finger safe electrical
  equipment components to avoid interlocks for
  personal protection against accidental electrical
  contact for voltages above 50V or stored energy
  above 10J in the equipment racks.
• Secondary AC distribution has also the
  accelerator equipment loads separated by
  equipment category and separate transformers are
  used to power magnet power supplies and beam line
  instrumentation.
• Emphasis is given to grounding and bonding.
  Ground loop impedances are measured before
  installation is released for operation.

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• DC and instrumentation cabling for accelerator
  beam line components is selected and approved by
  a three member committee. Main criteria are
  intended use, NEC, fire and radiation.
• Guidelines for accelerator beam line component
  cabling are written in the SNS document SNS
  109010200-DC0001-R02 Spallation Neutron Source
  Cabling Design Criteria.
• List of approved cables on line with manufacturer
  specifications and applicable UL and IEC listings.

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DESOGESO
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• The organizational chart is according to
  Standards Based Management System (SBMS) adopted
  by ORNL in 2002 for All employees
• Roles Responsibilities Accountabilities and
  Authorities (R2A2) define the relationship
  between the employee and the supervisor. R2A2
  also defines how ORNL intends to manage itself.
• R2A2 provides a template for training necessary
  for a employee to perform specific tasks.

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• Spallation Neutron Source Electrical Safety
  Committee Charter
• PURPOSE The Spallation Neutron Source (SNS)
  Electrical Safety Committee (ESC) is an internal
  review committee advisory to management regarding
  all issues related to occupational or
  environmental Electrical safety at the SNS. These
  issues include not only electrical safety for
  accelerator operations, but also compliance of
  electrical installations to NEC and OSHA 29CFR
  1910 S.
• Specifically, its duties are to
• Develop, review and update facility-specific
  policies that implement the ORNL Electrical
  Safety program, the Non Reactor Nuclear Facility
  Safety (DOE Order G-420.1-1), where applicable,
  enforce NEC and OSHA 29CFR 1910 S.
• Provide continuing assessment of facility
  compliance with ORNL requirements, DOE Order
  G-420.1-1, and the approved safety documentation
  (Safety Assessment Document and Safety Analysis
  Report) for the SNS. At a minimum, the committee
  will assess facility Electrical Safety before the
  startup of major SNS activities and review
  operating experience on a routine basis.

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• Recommend and provide training and authorization
  (certification) to Electrical Safety Officers
  (ESOs) to enable them to perform their duties.
• Review training requirements established for SNS
  staff, support organizations, users, and
  visitors.
• Review Electrical Safety aspects of proposed
  major facility changes (design reviews and
  installation recommendations).
• Recommend priorities for evaluating and
  controlling potential Electrical hazards from all
  sources at SNS.
• Review electrical installation, operation and
  maintenance procedures.
• Inspect Facility equipment upon installation or
  major reconfiguration changes for compliance with
  NEC and OSHA 29CFR 1910 S.

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• AUTHORIZATION The Committee is chartered by the
  SNS Associate Laboratory Director. The Committee
  reports to the SNS ESH Manager.
• MEMBERSHIP The membership shall consist of the
  chairperson, the SNS Electrical Safety Officers
  from SNS organizations with significant
  involvement in electrical work, including
  Accelerator Systems, Experimental Facilities, and
  Site Operations. The Committee will solicit
  other representatives to participate in standing
  or ad hoc subcommittees as deemed necessary.
• MEETINGS The Committee shall meet as determined
  by the chairperson, but at least quarterly.

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• RESPONSIBILITIES
• The SNS Associate Laboratory Director shall
• Determine the disposition of the Committee
  recommendations and communicate that disposition
  back to the Committee and to affected line and
  program managers of tenant organizations as
  necessary.
• Appoint the chairperson of the Electrical Safety
  Committee and the Electrical Safety Officers
  (ESOs).
• The chairperson shall
• Ensure that the Committee carries out the tasks
  specified in this charter.
• Solicit a representative from each organization
  having significant involvement in electrical work
  at SNS.
• Convene timely meetings.

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• Charter subcommittees or ad hoc working group
  e.g., for pre-startup readiness reviews.
• Ensure that minutes are kept recording Committee
  actions.
• Forward Committee recommendations to the SNS ESH
  Manager, as appropriate.
• Report ESC activities to the ESH Manager.
• Ensure that records are maintained of the
  disposition and implementation of Committee
  recommendations.

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• The Electrical Safety Officers shall
• Serve as a subject matter expert to the Committee
  in areas of Electrical Safety and regulatory
  compliance as mandated by OSHA.
• Ensure that activities at SNS associated with
  electrical installations, operation and
  maintenance are carried out in accordance with
  the ORNL Electrical Safety Program and SNS
  policies.
• Have signature authority to approve changes to
  the configuration of electrical equipment and
  installation.

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• Have the authority to interpret existing
  requirements and policies until such time as
  matters can be brought to the Committee for
  action.
• Serve as active members of the Committee
  including
• suggesting agenda items for meetings
• maintaining a list of Committee members
• keeping and distributing minutes of Committee
  meetings
• maintaining the records of readiness reviews for
  which the Committee is responsible
• maintaining records of the disposition and
  implementation of Committee recommendations

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• maintain records of approvals for unlisted
  electrical equipment
• maintain records of electrical distribution
  systems verification test reports
• APPROVED _________________________________
  _____________ SNS ESH Manager
  Date
• _________________________________
  _____________
• SNS Associate Laboratory
  Director Date

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• SNS adopted definitions
• 1. The initial activity is new installation.
  Installation describes the activity where new
  equipment and associated electrical wiring is
  installed. Good engineering and planning of
  installation shall prevent exposure of personnel
  to hazardous energies, i.e., no work shall be
  performed on energized (live) parts, as described
  in NFPA 70E Standard for Electrical Safety
  Requirements for Employee Workplaces. SNS LOTO,
  if necessary, shall be fully enforced including
  JHA (job hazard analysis).
• 2. The second activity is verification and
  testing of new installations. Verification
  describes the activity where the new equipment
  and the associated wiring is examined and
  approved as per applicable standards and good
  engineering practices and subsequently energized.

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• Testing describes the activity where energized
  equipment is being evaluated from safety
  requirements (testing and measuring of voltages,
  currents, impedances, etc.) This activity
  requires work on or near energized (live)
  electrical parts. The NFPA 70E Standard for
  Electrical Safety Requirements for Employee
  Workplace chapter 2 General Requirements for
  Electrical Work Practices shall be observed. The
  emphasis is on personnel qualifications, flash
  boundaries, personal protective equipment and
  approach distances. Proper planning (JHA) shall
  minimize hazards to the personnel, e.g.
  connection of test equipment on de-energized
  parts.

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• 3.The third activity is commissioning under the
  guidance of operations and area physicists.
• This again includes verification and testing as
  well as proper functionality of integrated
  electrical systems. This may include verification
  and testing, therefore all in the second
  paragraph applies to this activity from
  electrical safety point of view.
• 4. The fourth activity is maintenance.
  Maintenance describes activity where tested and
  commissioned equipment is being worked on to keep
  equipment and associated systems in good
  operational condition, also known as preventive
  maintenance. This activity is usually a scheduled
  activity, where work on energized equipment shall
  be prevented by all means - SNS LOTO and NFPA70E
  shall be fully enforced.

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• 5. The fifth activity is repair. Repair describes
  activity where work is being performed on
  equipment to restore the equipment into a good
  operating condition, usually after equipment
  failure. This activity shall be performed with
  the equipment de-energized.
• If the impact of de-energizing of the equipment
  will cause a significant monetary loss to the
  project, the project management with operations
  shall identify such repair work early, possibly
  during commissioning phase (e.g. CHL), and
  carefully evaluate the necessity of repairs on
  energized equipment. Electrical Safety Committee
  shall be asked for an independent evaluation.
• The emphasis again shall be on personnel
  qualifications, flash boundaries, personal
  protective equipment and approach distances.
  Proper planning (JHA) shall minimize hazards to
  the personnel, e.g. bypassing the energized
  equipment so the main work can be done on
  de-energized parts.
• Supervisors shall be responsible for currency of
  qualifications of personnel assigned to perform
  these tasks.

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• Summary of Electrical Safety Program
• Training
• Definitions
• Qualifications and qualification categories
• Hazard classification
• JHA
• Specific equipment JHA