Download TRTR 9_07 ACRR PD Up.. - National Organization of Test

Annular Core
Research Reactor
Instrumentation & Control Systems
Pulse Diagnostics System Upgrade
SAND #2007-4211
TRTR Conference 17-20 September 2007
Keith Barrett, PrimeCore
David Clovis, Operations Staff
Robert Zaring, Engineering Support Staff
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,
for the United States Department of Energy’s National Nuclear Security Administration
under contract DE-AC04-94AL85000.
Abstract
Sandia National Laboratories (SNL) and PrimeCore Systems have
developed a pulse diagnostic measurement system for the SNL Annular
Core Research Reactor (ACRR) based on PXI instrumentation and
leveraging ZTEC ZT410PXI modular oscilloscopes. The power and
flexibility of the PXI platform and the ZT410PXI 16-bit, 400 MS/sec
instrument enabled SNL and PrimeCore to replace and decidedly improve
an aging system based on 8-bit bench-top scopes, amplifiers, and long
cable runs. The ACRR allows scientists to perform experiments and test
components under extreme radiation exposure. The research reactor is
used to perform in-pile experiments for radiation effects, reactor
development, and safety requirements. These experiments are conducted
by “pulsing” the reactor, which allows for extremely high power levels to
be achieved for short periods of time. This power then decays
exponentially over time.
To ultimately capture the power measurements, Self Powered
Neutron Detectors (SPND) are placed just outside of the reactor core. They
generate currents that are proportional to the neutron flux of the reactor,
which can be related to the reactor power. The system employed by SNL
and PrimeCore then amplifies and converts the current to voltage using
termination resistors, a PXI current amplifier, and an external
programmable current amplifier. This method allows them to capture many
different ranges and conditions. Finally, the high-resolution ZTEC
ZT410PXI modular oscilloscopes acquire the voltage measurements and
transfer the data to a control computer for processing.
Pulse Diagnostics System Upgrade
Annular Core Research Reactor
• 500 pneumatic operations/yr
• 380 reactor pulses/yr
• Pulses: 33,000 MW peak power,
7-7.5 msec pulse width,
280-310 MJ
(Safety Limit: 500 MJ, 60,000 MW)
• Steady State: Limited by license to 2.0 MW
(increasing to 2.8 MW in November 2007), have
run as high as 4.0 MW.
Pulse Diagnostics System Upgrade
• Why upgrade old system?
– Replace Aging system
– Upgrade Instrumentation
– Improve Resolution and Accuracy, Reduce Noise
– Improve and simplify user interface
– Provide simple system calibration
Pulse Diagnostics System Upgrade
• System Output Comparison
~ 640,000 data points
~ 12,000 data points
Previous Pulse Diagnostic System
LowRange
SPNDs
HighRange
SPNDs
Pulse Timer
Trigger
I/V &
amplifier
I/V &
amplifier
Termination
Resistor
Termination
Resistor
Oscilloscope
Analog/Digital
Converter &
Storage
Diagnostics
Computer
System Overview
Control Room
HighBay Rack
Reactor Pool
Pulse Diagnostic
Control Computer
PXI Chassis
SPND
Detector
(2 to 4)
Or...
SPND
Detector
Or...
SPND
Detector
Or...
Keithley AC\DC Current
Source
(For System Calibration\Verification)
Logarithmic
Current Amplifier
(2 ChannelsPulse Only)
Or...
Termination
Adapter (2
Channels Pulse
and Steady)
Or...
Current Amplifier
(Steady State
Only)
Digitizers
(6 channels)
MXI
Link
Area 5
External Data File
Archive Computer
Control, Processing, Data
Storage
External Data Viewing
On Remote Computers
EMAIL Data Files to
experimenters
Key Hardware Improvements
• Reduced Cable Run
– Instrumentation is located in High Bay.
– Cable run is reduced, reducing system noise and capacitance.
– Fiber optic connection from instruments to computer in control
room.
• Improved Digitizers
– 8 bit scope replaced by 16 bit digitizer.
– Digitizer accuracy approximately 0.25% compared to >2%.
– Modular Instruments, Installed spare.
• Log Amplifiers
– Converts 10 na to 10 ma to .4 to 1.4 Volts
– Provides even resolution across 6+ decades of range. Approximately
5000 bits\decade of resolution compared with 512 bits (in 2 separate
ranges) of resolution in the old system.
Interconnect Diagram
Connections for Terminated Channels
ZTEC Digitizer Channel
(X6)
50 Ohm BNC
Cables RG174
Detector
(X4)
Termination Adapter
Connections for Log Amplified Channels
Detector
(X4)
Log Current Amp
(X2)
In
Out
Connections for Amplified Channels
Current Amplifier
(X2)
50 Ohm BNC
Cables RG174
ZTEC Digitizer Channel
(X6)
CH
50 Ohm BNC
Cables RG174
Detector
(X4)
CH
50 Ohm BNC Cables
RG174, 2 ft.
ZTEC Digitizer Channel
(X6)
CH
50 Ohm BNC Cables
RG174, 2 ft.
Calibration Interconnect Diagram
Keithley 6221
Calibration Connections For Terminated Channels
Termination Adapter
Out
ZTEC Digitizer Channel
(X6)
CH
BNC Cable RG174 3 ft.
Triax to BNC Adapter
Calibration Connections For Log Amplified Channels
Keithley 6221
Log Current Amp
(X2)
Out
ZTEC Digitizer Channel
(X6)
CH
BNC Cable RG174 3 ft.
Triax to BNC Adapter
Calibration Connections For Amplified Channels
Keithley 6221
Current Amp
(X2)
Out
BNC Cable RG174 3 ft.
Triax to BNC Adapter
ZTEC Digitizer Channel
(X6)
CH
PXI Instrument Layout
RS232 DB-9 Null Modem Cable From
Front of PXI To Rear of Current Source
Fiber Optic Cable
60 Meter
Control Computer
Control PC
PXI CHASSIS
8 Slot PXI Chassis (standard 19 inch rack mount)
Pwr
1
Pwr
2
Mxi
-4
Ztec
Dig1
Ztec
Dig2
2 ch
2 ch
MXI-4 Card
Blank
or
Dig3
Ztec
Arb
or
NI
4022
Amp
1U AIR GAP (PXI Draws Air From Bottom of Chassis)
Keithley 6221 Current Source
NI
4022
Amp
RS232
2 ch
PXI
Log
Amp
DL- 1641
(Internal Mount)
2 ch
DL- 1641
(Internal Mount)
Key Software Improvements
• Integrated System
– Single application runs the system, processes the data,
views and manages data.
– System calibration \ verification is built into the software
package.
– Excel is used as a post analysis and printing tool. It is
not used for signal processing and calculation.
– Predictive Calculations embedded in program.
• Source Code Control and Installation
– System will be an executable program with an installation
package for recovery.
– Algorithms will be “locked” with the executable. Can only be
changed with a new revision and release.
Software Flow Diagram
System Configuration
System Calibration
PDiag_SystemConfig.vi
Set up instrument addresses,
Cal Factors, Amplifier Config.
PDiag_SystemCal.vi
Performs a calibration \
verification of all channels.
Welcome Screen
PDiag_WelcomeScreen.vi
Top Level Program
Provides access to all functions
Pulse Configuration and
User Entry
Steady State Configuration
and User Entry
PDiag_PulseUserEntryScreen.vi
Set up Pulse and enter user fields
PDiag_SSUserEntryScreen.vi
Set up Steady State Run
Pulse Acquisition
Steady State Acquisition
PDiag_Pulse Acquistion.vi
Arms System and Acquires Data for Pulses
Performs Analysis
PDiag_SteadyStateAcq.vi
Arms System and Acquires Data
Steady State Data Viewer
Pulse Data Viewer
PDiag_SteadyStateViewer.vi
View\Analyze Steady State Runs
PDiag_PulseViewer.vi
View\Analyze Pulse Runs
Data Processing Flow
Logic Flow for Data Processing
Excel Summary File
Raw Pulse.wfm
Data Processing
Routine in ACRR
Pulse Diagnostic
Program and Data
Viewer Application
LabVIEW Results Screens
\ Data Presentation Program
Processed.wfm
Processed.wfm
Export to CSV Files (Text)
Export to Diadem
Data Viewing Methods
Data Viewing Methods
Pulse Diag Computer
or Network Group Drive
Data Viewer Program
Running On Remote
Computer
Data Files
Use Pulse Diagnostic Machine or Network drive as a file server: The data viewer
application can be installed on other machines and use the data files from the pulse
diagnostic computer. .
Pulse Diag
Computer
Main Program
EMail
Server
Data Files
Experimenters
Computers
EMail Excel files to experimenters.
OPTIONAL????
Data Viewer Program
Running On Pulse Diag
Computer
LabVIEW
Remote
Panels
Internet Explorer
Running on External
Computer
Software Design\Implementation
• Simple Architecture, Clean
Program. Basic event
driven interfaces with
simple state machines.
• Object based data flow.
• Modular programming.
• Basic Documentation in
Code
• Source Code Delivered to
ACRR
• LabVIEW 7.1
Pulse Diagnostics System Upgrade
• Future Work
– Allow for measurement in Transient Rod Withdraw
Submode.
– Obtain better results for Steady-State operations
<5% Rx Power.
– Procure new larger SPND, install, and configure.
End result:
Pulse Diagnostics
Operational!!!
A job well done to all involved!!!
Questions???
How much did it cost? $105K - significant cost savings in not immediately adding new larger volume SPNDs. Plans to
upgrade to a large Cad will occur after the fact and cost another $60K.
How long did it take? - 4 months to become operational, testing and tweaking is still ongoing as we have time.
How much regulator involvement was required? - Not much, since it's not a safety system it required little oversight. No
control functions are dependant on pulse diagnostics. Our wide-range and PPS channels still control shutdowns & scrams.
What is benefit to experimenters? - Dramatically improved resolution of pulse energy versus time, significantly more
flexibility in processing data, and the ability to reprocess raw data from prior tests (of the new system).
Data output and detector sharing flexibility? - Any detector can be aligned with any amplifier fairly easily. Multiple
choices for output, including standalone data viewer where an experimenter can reprocess the raw data from his desktop.
Why is ‘pulse’ diagnostics used for ‘steady-state’ operations? - By using the same detectors we can achieve decent power
trace resolution at ~5 % (120 kW) which allows for long-term plotting of SS data and associated parameters. We expect
significant improvement (i.e. able to trace power at much lower levels say 1.2 kW) with the new large Cad detector.
How difficult is ‘power’ calibration for pulse detectors? - Calibration from the detector input to the PC is a simple process
using a current source and the operating program. The program controls the current source running through a prescribed
routine. Calibration of the actual pulse vs. the measured pulse is a ‘whole nother story’. We have no idea what our pulses
REALLY look like. Input impedance is a large factor in trying to trace power from ≤ 1 kW to ~33 GW by measuring
current. We "back calibrate" our pulse height based on dosimetry data of overall MJ based on theoretical pulse shapes.
Can the ‘new’ system interpret ‘old’ system data? - YES. It can also compare data over multiple runs. We cannot
reprocess old system data since the raw inputs were not saved.
Are there unique features of the new system? The ability to integrate reactor energy during any part of the pulse is a built
in flexibility of the new system compared to old system. Some experimenters only care about integral energy during
portions of the pulse (say immediately after a circuit is energized).
Are there any cost savings of the new system? The new system saves calibration costs (~$1200 per year) of old scopes.