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Accelerator Systems Management Overview

Presented to SNS Accelerator Advisory Committee Presented by Kevin Jones Research Accelerator Division Director March 24, 2015

2 Accelerator Systems Management Overview


There have been a number of management changes in NScD since the last meeting of the AAC

Associate Laboratory Director Paul Langan

Herb Mook, Senior Corporate Fellow Emeritus Jeanine Evans, Executive Secretary

Matrix Support Bonnie Hébert, HR Manager

Lorie Hickey, Business Manager

Directorate Operations Hans Vogel

Scientific and Program Services Office Crystal Schrof

Joint Institute for Neutron Sciences

Takeshi Egami

Deputy Associate Laboratory Director

Rob McQueeney

Chief Scientist

Alan Tennant

Research Reactors

Tim Powers

Research Accelerator Kevin Jones

Instrument and Source

Don Abercrombie (Acting)

Quantum Condensed Matter

Stephen Nagler

Chemical and Engineering Materials

Richard Ibberson

Neutron Data Analysis and Visualization Thomas Proffen

Biology and Soft Matter

Volker Urban (Acting)


Likewise, RAD has been reduced in size and scope to accommodate other organizational changes – mission remains focused on site, accelerator and target

Research Accelerator Division Kevin Jones, Director

Conventional Facility Operations

Sam McKenzie

Data Operations Karen White

Accelerator and Target Operations

George Dodson

Electrical and RF Systems

Mark Champion

Mechanical Systems and Operations

Michael Baumgartner

Superconducting Linac Systems

Sang-ho Kim

Maintenance Management &

Information Systems George Dodson

Accelerator Operations Glen Johns

Accelerator Physics, Beam Instrumentation

and Ion Source John Galambos

Control Systems Karen White

Instrument Data Acquisition and

Controls Steve Hartman

SNS ESH&Q Greg Rowland (Interim)

Facility Maintenance – Chestnut Ridge Sam McKenzie

Site Services Tom McLaughlin

NRPD Assignment – Radiological Control

George Stephens

Transferred to other organizations:

•  Instrument Operations (ISD) •  Scientific Information Systems (SPSO) •  Deployed SNS IT (SPSO)

The RAD is responsible for the operation, maintenance and improvement of the SNS accelerator complex

The front end produces a 60 Hz, ~1 ms long chopped H- beam

Accumulator Ring: Compress ~1 msec pulse to 700 nsec

2.5 MeV

Superconducting LINAC Front-End

RTBT

HEBT

Injection Extraction

RF

Collimators

945 ns

1 ms macropulse

Cur

rent" mini-pulse

LEBT chopper system makes

gaps

Current"

1ms

Liquid Hg Target

~940 MeV

~1 ms macropulse 1 ms

~700 nsec

186 MeV

Warm Linac

•  SNS is the highest power pulsed neutron source in the world

•  The machine has over 100,000 control points and cycles ~5.2 million times a day

•  Power (and base neutron flux) is the product of: –  Beam Energy –  Peak Current –  Chopping Fraction

–  Pulse Length –  Repetition Rate


SNS design parameters Kinetic Energy 1.0 GeV Beam Power 1.4 MW Linac Beam Duty Factor 6% Modulator/RF Duty Factor Specification 8% Peak Linac Current 38 mA Average Linac Current 1.6 mA Linac pulse length 1.0 msec Repetition Rate 60 Hz SRF Cavities 81 Ring Accumulation Turns 1060 Peak Ring Current 25 A Ring Bunch Intensity 1.5x1014 Ring Space Charge Tune Spread 0.15


SNS performance relative to design Design Best

Ever Routine

Operation

Kinetic Energy [GeV] 1.0 1.07 0.939 Beam Power [MW] 1.4 1.427 0.8-1.35 Linac Beam Duty Factor [%] 6 6 5 Modulator/RF Duty Factor [%] 8 8 7 Peak Linac Current [mA] 38 42 35 Average Linac Current [mA] 1.6 1.6 1.1 Linac pulse length [msec] 1.0 0.98 0.8-0.9 Repetition Rate [Hz] 60 60 60 SRF Cavities 81 80 80 Ring Accumulation Turns 1060 1020 825 Peak Ring Current [A] 25 26 18 Ring Bunch Intensity 1.5x1014 1.55x1014 1.1x1014

Ring Space Charge Tune Spread 0.15 0.18 0.12


The SNS neutron source has achieved stable 1MW operation capability for 4500 hours at ≥90% reliability

Since FY09 the SNS neutron source has exceeded all DOE PMM operational commitments for hours delivered and availability

65#

70#

75#

80#

85#

90#

95#

0#

1000#

2000#

3000#

4000#

5000#

6000#

FY07# FY08# FY09# FY10# FY11# FY12# FY13# FY14# FY15#(02/15)#

Reliability#(%

)#

Hou

rs#or#MW/Hrs#

SNS#OperaEonal#Performance#FY07#/#FY15#

Neutron#ProducEon#Delivered#

Neutron#ProducEon#Commitment#

MW/Hr#

Down#Time#

Reliability#

Reliability#Commitment#

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DOE PMM Hours and Availability are not the same as scheduled hours and availability: •  Annual DOE BES

Facility Questionnaire submitted in October sets planned hours for that FY

•  Neutron Production Commitment is 90% of planned hours

•  Schedule has contingency and is published quarterly one month in advance

•  Additional hours are provided

•  Possible to meet DOE PMM of 90% while not meeting 90% against published schedule


SNS FY 2016 Q1-4 Planning Only (02-23-15)

1 1 1 1 1 1 1 1 1 1 1 12 2 2 2 2 2 2 2 2 2 2 23 3 3 3 3 3 3 3 3 3 3 34 4 4 4 4 4 4 4 4 4 4 45 5 5 5 5 5 5 5 5 5 5 56 6 6 6 6 6 6 6 6 6 6 67 7 7 7 7 7 7 7 7 7 7 78 8 8 8 8 8 8 8 8 8 8 89 9 9 9 9 9 9 9 9 9 9 910 10 10 10 10 10 10 10 10 10 10 1011 11 11 11 11 11 11 11 11 11 11 1112 12 12 12 12 12 12 12 12 12 12 1213 13 13 13 13 13 13 13 13 13 13 1314 14 14 14 14 14 14 14 14 14 14 1415 15 15 15 15 15 15 15 15 15 15 1516 16 16 16 16 16 16 16 16 16 16 1617 17 17 17 17 17 17 17 17 17 17 1718 18 18 18 18 18 18 18 18 18 18 1819 19 19 19 19 19 19 19 19 19 19 1920 20 20 20 20 20 20 20 20 20 20 2021 21 21 21 21 21 21 21 21 21 21 2122 22 22 22 22 22 22 22 22 22 22 2223 23 23 23 23 23 23 23 23 23 23 2324 24 24 24 24 24 24 24 24 24 24 2425 25 25 25 25 25 25 25 25 25 25 2526 26 26 26 26 26 26 26 26 26 26 2627 27 27 27 27 27 27 27 27 27 27 2728 28 28 28 28 28 28 28 28 28 28 2829 29 29 29 29 29 29 29 29 29 29 2930 30 30 30 30 30 30 30 30 30 30

31 31 31 31 31 31 31

Accelerator Physics Machine Downtime Major Periods(Maintenance/Upgrades)Accelerator Startup/Restore Scheduled Maintenance (starts at 06:30)Accelerator Physics/Maintenance Periods Neutron Production Major Unplanned Outages for Failures (background color is original plan) Transition to Neutron Production

Apr-2016 May-2016 Jun-2016 Jul-2016 Aug-2016 Sep-2016Oct-2015 Nov-2015 Dec-2015 Jan-2016 Feb-2016 Mar-2016

Apr-2016 May-2016 Jun-2016 Jul-2016 Aug-2016 Sep-2016Oct-2015 Nov-2015 Dec-2015 Jan-2016 Feb-2016 Mar-2016

SNS will have a significantly reduced operating schedule in FY2016 - ~3,500 scheduled hours for neutron production

•  Current target may survive to end of FY2015 – will be at or near water shroud radiation damage limit •  Inner Reflector Plug (IRP) is nearing end-of-life of ~32 GW-Hr (neutronic burn-up of moderator poisons) – could reach 32 GW-Hr in

December depending on operating conditions after April •  New IRP scheduled for installation next summer – assumes delivery on schedule at end of CY2015 •  Possible change-out of RFQ in parallel with IRP in Summer 2016


SNS experienced three major equipment failures in September – November 2014

SNS Target Module on Cart – Retracted Position

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Utility Jumpers

Shielded Cart

Replaceable Target Module

•  At 10:30 pm on September 11, 2014 Target 10 indicated a mercury leak into the interstitial space that was confirmed using standard techniques

•  While the target change was in progress, at 12:30 pm on September 15, 2014 the chopper target in the MEBT ruptured catastrophically, filling the MEBT vacuum envelope with water that vented through pressure relief valves

•  At 11:45 pm on October 27, 2014 Target 11 indicated a mercury leak into the interstitial space that was again confirmed using standard techniques

•  Again reduced to one spare target – entered target conservation mode with operation at 850 kW

MEBT Chopper Box – water visible in view ports


The MEBT water event was difficult to recover from

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Utility Jumpers

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•  DTL was also affected (isolation valve unseated under water pressure) requiring replacement of subset of ion pumps

•  Electrically complex environment – needed comprehensive approach to hazardous energy control

•  Required full disassembly of the MEBT (except for removing the 4 rebunching cavities) to properly dry and rehabilitate equipment

•  Dewatering the rebunchers was tricky – final solution was to circulate heated glycol mix through the cooling passages at temperatures >100C but below O-ring limits of ~120C

•  Excellent performance by a large team of people – no safety issues and only two minor equipment events during recovery

MEBT before disassembly

MEBT after disassembly

Dewatering rebunchers


SNS has also experienced a number of other operational events since March 2013

•  The PPS event of August 2013 was very significant – ASE violation, and required DOE concurrence for restart, which was achieved in 9.5 days

Shielded Cart

FY 2014

Dec Jan FebMar Apr May Jun Jul Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep NovOctAug

FY 2013

LEGEND

- Radiological EventsTRCDART

- Injury Events

12

02

00

35

03

15

24

26

23

13

24

13

14

02

03

11

16

37

12

12

00

- Events to NTS Reportable

ORPS Events Non-ORPS Events

Failure to Wear PPE

Conduit Damaged During Excavation

Worker Suffers a Fracture of Right

Wrist

Worker Suffered a Metatarsal Bone Break

Employee Sustains Shoulder Injury

Resulting in Surgery

Mild Elec. Shock from Unplugged Lab. Equip.

Visiting Researcher Failed to Correctly

Apply LOTO

Hazardous Energy Control Procedural

Violation

Worker Suffers a fracture of Left Ankle

Unexpected Discharge of

Cryogenic Helium

Electrical Conduit Damaged during

Removal of Sidewalk

Facility Evacuation During Testing

Activity

Discovery of Non-Operable Safety System at SNS

Shoulder Injury Requiring Surgery

Worker Sustains Injury Requiring

Surgery

Employee Knee Injury Requiring

Surgery

Discovery of an Uncontrolled

Electrical Hazard

Injury to Arm Requiring Surgery

Electrical Program Weaknesses

Near Miss – Falling Hutch

Energized Electrical Cable

Severed

Elbow Injury Requiring Surgery

Fume Hood Fire with Explosion

Radioactive Sealed Source

Control

Subcontractor Injured Requiring

Surgery

Fire Engine Hose Bed Drive

Mechanism Fails

Employee Knee Injury Requiring

Surgery

13

Programming Error Results

in USQ

Knee Injury Requiring Surgery

Vacuum Tank Tips off Pallet

during Transport

13

01

Near Miss Installing a Glove

Box

Mild Electrical Shock (NNFD)

Contaminated Water in SNS

Off-Gas System

Vendor Receives Electrical Shock


Severed


Severed

Chronic Occupational

Illness

SNS Target Failure

SNS Target Failure

Mild Electrical Shock (ESD)

Discovery of Exposed Electrical

Contacts

Inconsistent Software Version

on IPPS (SNS)

Energized 120V Conduit Severed

Mild Electrical Shock (SNS)

Material Handling Programmatic

Unexpected Airborne

Radioactivity

Non-energized Electrical Cable

Removed during D&D

FY 2015

Worker Suffers Fractures to Both

Lower Legs

Worker Receives Shock from Jib Hoist

Fall Results in Fractured Wrist

SNS Linac Trap Key Assembly

Mechanical Failure


The outcome of the DOE Cost Review in November 2013 was generally positive for accelerator aspects

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•  The advice received from this committee was helpful in our preparations

•  “The reviewers noted the benefits and efficiencies of the new organization: –  “The integration of the facility operations groups and crafts into the accelerator operations division.”

•  “Other items of special mention from the reviewers: –  “The high reliability of the accelerator and the continuing efforts to push toward the 1.4 MW design

power level. –  “The effort to improve quality control and lifetime predictability of the SNS Hg target following the

disastrous sequential failure of two targets in October 2012.”

•  “SNS Specific Recommendations: –  “SNS must continue to make improvements that will facilitate sustained operation at the 1.4 MW

power level while maintaining better than 90% reliability. A timeline for 1.4 MW operation should be provided to BES.

–  Target reliability and lifetime issues must be quantified so that a predictable run schedule can be maintained without major concern over unexpected target failures.”

•  “The SNS and HFIR have demonstrated great progress over the past two plus years in reaching the goal of providing world leading scientific facilities for neutron scattering. … Optimization of …. must be the overarching priority for the facilities to meet or exceed their potential in producing high impact science. The management and staff are to be congratulated for embracing this goal and refocusing their efforts to achieve maximum scientific productivity.”


This committee is asked to assess our operations, our path to sustainable 1.4 MW operation, and the plans for the Second Target Station

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1.  Assess the performance of the accelerator complex and neutron source since the last meeting.

2.  Assess and provide advice on the plans for sustainable beam operation with availability at the ≥90% level at ~1.4MW beam power for 5000 operating hours per year in a constrained funding environment. Consider the lessons learned from the high power run in the first half of 2014 and current maintenance strategy.

3.  Assess the adequacy of our approach to sustaining and developing critical systems, including High Voltage Converter Modulators, Superconducting Cavities (plasma processing), Injection Stripping (Foils, lasers), Personnel Protection System and Controls (including high level applications) and the Integrated Front End Test Stand facility.

4.  Is the SNS response to the observed RFQ issues adequate?

5.  Does the AIP investment strategy align with the 1.4MW reliable, sustainable operation and STS path?

6.  Provide advice on the accelerator systems components of the draft technical design report for the Second Target Station and provide guidance on the reasonableness of the updated plan for the power upgrade in the SCL, with fewer new Cryo-modules than originally planned.


Summary •  We can operate reproducibly with beam power ≥ 1 MW and availability ≥ 90%

•  While we meet or exceed operating commitments many significant challenges remain

•  Our immediate focus is on sustaining availability and continuing operation at the highest possible power subject to Target and RFQ limitations

•  Our medium term effort will achieve reliable 1.4MW operation by 2017, lay the foundation for 3MW capability and maintain the potential to carry out the Second Target Station project

•  Institutional commitment has been essential to our success

The hard work, dedication and talent of the SNS staff enable these achievements

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