Implementation of DOE O 420.2C at PPPL for NSTX-U Jessica Malo - Safety Analyst, Princeton Plasma Physics Lab ASO Team DOE Accelerator Safety Workshop 2018

Outline Messages What is NSTX-U? ASO Requirements and Applicability Introduction to NSTX-U - Mission, Design, Shielding & Access Control Accelerators vs. NSTX-U Required Program Elements ASO Implementation Plan Scope Status Update Summary Timeline

Messages The ASO was added to our contract since our 2016 run and is required for restart Elements of the ASO have existed on NSTX-U before but with less rigor The ASO provides an opportunity to improve NSTX-U and sustain improvement well into its future The ASO Implementation planning effort has already provided benefits to the project and future operation We look forward to benefiting from the Accelerator community keep as is

NSTX-U ASO Implementation Goals NSTX and NSTX-U start up activities performed 14 times in the past Since last restart the ASO is now included in PPPL contract Now we must merge technical aspects and ASO implementation and approvals Goal 1 Prepare NSTX-U for commissioning and restart technically Goal 2 Prepare NSTX-U for Accelerator Readiness Review per ASO Goal 3 Complete ARR with approved ASE Goal 4 Obtain DOE-PSO approvals to I) commission and II) operate Goal 5 Commission and then operate

What is NSTX-U? The mission of the National Spherical Torus Experiment Upgrade (NSTX-U) is to establish the potential of the ST configuration as a means of achieving practical fusion. The magnetic field in NSTX forms a plasma that is a torus since there is a hole through the center, but where the outer boundary of the plasma is almost spherical in shape, hence the name “spherical torus” The compact shape of spherical tokamaks enables the confinement of highly pressurized plasma within lower magnetic fields than conventional tokamaks, potentially making them more cost-effective. NSTX is yielding research results that may open a path towards developing fusion energy as an abundant, safe, affordable and environmentally sound means of generating electricity. subcategory or tokamaks where aspect ratio is low. aspect ratio on upgrade is 1.7 .93 meters major radius, minor radius is .6ish

Why does 420.2C Apply? NSTX-U Fits the Definition of an Accelerator in the Order Accelerator definition: “A device employing electrostatic or electromagnetic fields to impart kinetic energy to molecular, atomic or subatomic particles and capable of creating a radiological area.” While NSTX-U is not a conventional accelerator, it does accelerate charged particles and has the capability to create a radiological area, and therefore meets the definition of an accelerator in DOE O420.2C .

Here is a Typical Tokamak A device that uses a powerful magnetic field to confine heated plasma in a toroidal (doughnut) shape. Plasma fills a large volume within the vacuum chamber One of several types of magnetic confinement devices. Design intended to drive future development of controlled fusion power.

NSTX-U Magnets PF1B Coil PF2 Coil PF1C Coil PF3 Coil PF1A Coil Vacuum Vessel PF5 Coil RF Antennas TF Coil Outer Leg PFC Tiles TF Coil Inter Leg Center Stack Assembly OH Coil

Key Differences - What is a “beam”? Accelerator “beam” can be best compared to NSTX-U “plasma current” An accelerator is “on” when beam is present...NSTX-U is “on” when there is plasma current present. Accelerator beams are ~100 mA NSTX-U Plasma current is ~1-2 MA - charge carriers generally have lower energy, but there are more of them However, we (confusingly) use “Neutral Beams” to heat the plasma. Neutral beam = 1-2 MW beam of neutral deuterium atoms, injected into the plasma; ~60 A of neutral current at ~90 kV acceleration voltage. (.5 m high x .125 m wide each source x 6) Key point: we can make a radiological area if plasma current is present, even without beams, or beams conditioning without plasma current. replace “beam” with “NB” wherever referred to our machine. neutral beams condition into copper targets to get ready for plasma injection pulses. These copper lattices hold D. The beam D and D in the copper collide at sufficient energies to make neutrons. Unlike a traditional accelerator’s continuous operation, NSTX-U operates in short pulses, resulting in 1-5 second plasmas separated by 15-40 minutes

NSTX-U and Neutral Beams TF Coil Ion Source NBL-1 NSTX-U Vacuum Vessel 3 ion sources per BL on 4 degree fan array . BL2 converge at Bay K port. (BL1 Bay A) Calorimeter Ion Dump/ Bending Magnet Assembly NBL-2

Sources of Radiation During Operations from NSTX-U Hard X-rays from Runaway Electrons - If very low density plasma is inadvertently formed (low or no fueling), the plasma current can transfer to a small population of very energetic electrons X-rays from thermal plasma Neutrons from calorimeter operations - Calorimeters have implanted deuterium D-D fusion reactions occur with implanted deuterium D-D fusion makes 2.45 MeV neutron or a 3 MeV proton Neutrons from NB+Plasma fast ions from neutral beam injection collide with background particles, leading to D-D fusion reactions collisions of the plasma ions lead to D-D fusion reactions

NSTX-U Test Cell Configuration Dimensions are 60’ x 114’, by 54’ 6” high 4’ thick north, south, and west walls, 3’ thick for northeast diagonal and east walls; 3’ thick floor. Doors on north and south east sides Numerous penetrations in the walls and floors. Four instances of Motorized Movable Shielding shielding Battleship door on north side. Large door to TFTR test cell on south side Large door to Neutral Beam Power Conversion building on south side. Small sample door on NE diagonal wall We generally intend that this shielding will prove sufficient for all radiation scenarios, some improvements are in progress. Part of safety assessment will look at neutron shielding, which is in good shape because we have robust concrete shielding. Safety is assured through our radiation area being limited to a controlled, well-shielded test cell with access restricted. Neutrons in, people out.

NSTX-U Test Cell Access Access Control: Search and secure Door locks and redundancy HIS Annunciation Human Interface Secure - All hard-wired; no computers - cannot be interfered with by hackers. HVE: High voltage enclosure. power supplies converge in HVE to power the ion source. NBI Duct: Neutral Beam Injection Duct TVPS: Torus Vacuum Pumping System Search and secure: Machine techs walk through and physically check, visually and shouting. Door Locks and redundancy: lock people out, not in. HIS: Hardwire interlock system - the loop is set: kirk keys and door interlocks are set ensuring that the test cell is secure. No computer control. all hardwired. Power supplies cannot be enabled until loop is set and the COE manually enables each system. That allows the power suppleis to apply power, then the COE also applies the “arm” function. This is another manual COE action that brings the power supplies up to where they can be triggered by the clock. until they are armed manually by the COE, they are energized but cannot pulse. cannot be triggered until armed. Annunciation: Lights on all access doors and in the control room (COE’s station) indicating access status. Free access, controlled access, or no access. Human interface: describes the process by which COE can alter the state of the access control system by controlling power supplied. Nothing computer: In some SAD’s the fact that we do not have anything digital, we are not using computers, everything is hardwired. Dashed lines indicate the access-controlled area.

Inside NSTX-U Technicians Inspecting Center Stack Tiles keep, but place after slide 9. Technicians Inspecting Center Stack Tiles

Required Program Elements from DOE O 420.2C Accelerator Safety Envelope (ASE) which defines the physical and administrative bounding conditions and controls for safe operations based on the safety analysis documented in the SAD; Safety Assessment Document (SAD), representing the technical basis for the ASE; Clearly defined roles and responsibilities for accelerator activities including those for training and procedures; An unreviewed safety issue (USI) process supporting configuration management efforts that help ensure the facility and safety documentation are maintained current and periodically updated; An Accelerator Readiness Review (ARR) program to ensure adequate preparedness for safe commissioning and full operations A current inventory of accelerators under 420.2C and exemptions or equivalencies granted in accordance with paragraph 3.c.(2) and 3.c.(3) the Order (kept by the ES&H Department). Make this “what we have to do”, then replicate it and replace the USI slide with it and give a status uodate “here is where we are, and include the USI process development into that”

ASO Implementation Plan Scope An Accelerator Safety Order Implementation Plan document (ASOIP) has been developed for stakeholder approval and is in the review and approval process ASO Team: We have a strong team in place to manage the work Configuration Management evaluation Preparing Training Plan and perform training Preparing Commissioning Plan and procedure update PPPL Activity Certification Committee Review (internal) ARR and DOE-PSO Approvals to commission and to operate Implement procedures to commission Achieve Recovery KPPs place after green “goals” slide.

ASO Implementation Team The ASO Implementation Team has been established to develop and expedite plans moving forward. This team consists of: NSTX-U Chief Operations Engineers (Blanchard, Camp, DePasquale) NSTX-U Senior Operations Supervisor (Cropper) Neutral Beam Operations Supervisor (D’Agostino) Jessica Malo, ASO Safety Analyst, Nuclear Engineer Jerry Levine, Head of ES&H Department Charles Gentile, ACC Chair for NSTX and NSTX Upgrade T. Stevenson, Head of NSTX-U Operations, Heating Systems, Con Ops Mgr. S. Gerhardt, Recovery Deputy Project Director/NSTXU Research Operations Head Additional lab support when needed high visibility for the project.

Supporting Plans In addition to the ASOIP, several additional plans have been developed and are in the process of review and approval. These plans include: Activity Certification Committee (ACC) Plan Commissioning Plan Procedure Update Plan Training & Qualification Plan Accelerator Readiness Review (ARR) Plan Move to a better location

Updates to SAD/ASE/AOE planned NSTX Upgrade Safety Assessment Document (SAD) exists from our NSTX-U Readiness for Operations Review A comprehensive safety analysis will be performed against a risk methodology NSTX-U SAD will be updated as noted for ACC/ARR Accelerator Safety Envelope established with credited controls for ARR review Conduct ARR to ensure NSTX-U is ready for safe commissioning and operations Obtain DOE-PSO approval of commissioning plan and ASE to allow commissioning, start up, and operations Accelerator Operating Envelopes (AOE) envisioned Our technical procedures will define and enforce the AOE boundary parameters put after ASO Implementation plan scope slide

Technical Steps Required for NSTX-U Restart 1: Pre-Ops Testing - Pump-Down - System PTPs - MG Run Ups - FCPC Pre- Operational Tests and Potentially Dummy Load Testing - Laser Calibrations - Interlock testing - NB pre-operational tests - LHe Refrigerator Operations 2: Non-Accelerator Operations (Power in test cell but no plasma production with potential to create a radiological area) - Bakeout and boronization - Single coil operations, including w/ MG - NBI Arc Chamber Conditioning 3: Accelerator Commissioning (These activities will accelerate charged particles and make a radiation area) - Combined field test shots (Recovery KPP) - Neutral beam high voltage conditioning (Recovery KPP) - Plasmas with no neutral beams - Plasmas with neutral beams for shot development, up to some agreed level. 4: Accelerator Operations - Further development of the plasma scenarios - Science operations - Staged introduction of HHFW - Staged introduction of lithium close to the end - but keep. between 1 and 2 is ARR pt 1. Between 2 and 3 is ARR pt 2.

Summary & Current Status Required Elements Current Status ASE We have a safety certificate which historically served the function of a safety envelope for the era prior to the ASO. This only required internal approval. An updated version will become the ASE upon PPPL & DOE approval. SAD PPPL will soon begin revising the SAD to meet the changes needed to satisfy the ASO. Training & Procedures Technical Procedure update is underway. Configuration Management is in place. Training Plan is being developed & will be updated prior to the ARR. This will be used to re-establish operating team required for safe operation of NSTX-U: Refresher operator training (ongoing for testing) NSTX-U NTC Assessor training (ongoing) USI training SAD/ASE training USI process USI process has existed as an internal lab process, but after the ARR, the adjudication of USI’s will be approved by PSO. ARR program Accelerator Readiness Review preparations are ongoing. Accelerator Inventory Kept by ES&H Department - For now, NSTX-U is the only accelerator. The schedule will be baselined in Fall 2018. Based on current projections, the ARR will take place in June 2020, with a return to operations in January 2021.

Questions?