Masters Thesis- Criticality Alarm System Design Guide

246 Pages·2009·4 MB·English

by  Bryce Greenfield

PNNL-18348
Prepared for the U.S. Department of Energy
under Contract DE-AC05-76RL01830
Masters Thesis- Criticality Alarm
System Design Guide with
Accompanying Alarm System
Development for the Radioisotope
Production L

BA Greenfield

December 2009
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(9/2003)

CRITICALITY ALARM SYSTEM DESIGN GUIDE WITH
ACCOMPANYING ALARM SYSTEM DEVELOPMENT FOR
THE RADIOCHEMICAL PROCESSING LABORATORY IN
RICHLAND, WASHINGTON

BY

BRYCE GREENFIELD

ASSOCIATE OF SCIENCE - COMPUTER SCIENCE
WHATCOM TECHNICAL COLLEGE
2004

BACHELOR OF SCIENCE - NUCLEAR ENGINEERING
UNIVERSITY OF NEW MEXICO
2007

THESIS

Submitted in Partial Fulfillment of the
Requirements for the Degree of

Master of Science
Nuclear Engineering

The University of New Mexico
Albuquerque, New Mexico

December, 2009
Acknowledgements

I would like to thank Dr. Robert Busch. Your tireless effort and dedication is
inspiring. The countless hours you have spent correcting my assignments and instructing
me is truly appreciated. My work has been well received here at PNNL, and I feel that
the credit is due to your patience and commitment to delivering a quality education to
your students.
To all of my committee members, I would like to extend a heartfelt thank you for
all that you have done. Through both undergrad and graduate levels Dr. Gary Cooper
and Dr. Taro Ueki contributed so much to my education. The rigor of your classes may
not have been entirely appreciated at the time, but is now more appreciated than you
could know. Unfortunately I had finished my coursework before Dr. Adam Hecht
arrived at UNM. However, from the very inception of this thesis writing process, he has
offered his help and guidance, which was extremely valuable.
To all of those individuals at PNNL who have given me assistance over the last
three years, thank you. With no exception, every staff member that I have encountered
has been more than willing to lend a hand. Andrew Prichard deserves special mention.
From the moment I arrived at the lab, he has painstakingly mentored me and taken the
time to not just answer my questions, but to make me understand those answers. His
never wavering patience and endless amounts of knowledge make him the ideal mentor.
And finally to my wife, Robin, words can not convey the heartfelt appreciation
and love I have for you. Without your support I would be lost.
iii
CRITICALITY ALARM SYSTEM DESIGN GUIDE WITH
ACCOMPANYING ALARM SYSTEM DEVELOPMENT FOR
THE RADIOCHEMICAL PROCESSING LABORATORY IN
RICHLAND, WASHINGTON

BY

BRYCE GREENFIELD

ABSTRACT OF THESIS

Submitted in Partial Fulfillment of the
Requirements for the Degree of

Master of Science

Nuclear Engineering

The University of New Mexico
Albuquerque, New Mexico

December, 2009
CRITICALITY ALARM SYSTEM DESIGN GUIDE WITH ACCOMPANYING
ALARM SYSTEM DEVELOPMENT FOR THE RADIOCHEMICAL
PROCESSING LABORATORY IN RICHLAND, WASHINGTON

by

Bryce Greenfield

B.S., Nuclear Engineering, University of New Mexico, 2007
M.S., Nuclear Engineering, University of New Mexico, 2009

ABSTRACT

A detailed instructional manual was created to guide criticality safety engineers
through the process of designing a criticality alarm system (CAS) for Department of
Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements
were both addressed. A list of design tasks and technical subtasks was compiled and
analyzed to provide concise direction for how to complete the analysis.
An example of the application of the design methodology, the Criticality Alarm
System developed for the Radiochemical Processing Laboratory (RPL) of Richland,
Washington is also included. The analysis for RPL utilized the Monte Carlo code
MCNP5 for establishing detector coverage in the facility. Based on the design
methodology, significant improvements to the existing CAS were made that increase the
reliability, transparency, and coverage of the system.
v
Table of Contents

Acknowledgements .......................................................................................................... iii
ABSTRACT ....................................................................................................................... v
List of Figures .................................................................................................................. vii
List of Tables .................................................................................................................. viii
Chapter 1 – Introduction ................................................................................................. 1
Minimum Accident of Concern ................................................................................................ 2
Objective ..................................................................................................................................... 3
Overview of Chapters ................................................................................................................ 4
Chapter 2 – Literature Review ........................................................................................ 6
Chapter 3 – Design Process Overview .......................................................................... 14
Design Methodology ................................................................................................................ 16
Chapter 4 – Application of Guideline Methodology .................................................... 49
Chapter 5 – Conclusion .................................................................................................. 94
Summary .................................................................................................................................. 94
Future Work ............................................................................................................................ 94
Enhancements .......................................................................................................................... 95
Definitions ........................................................................................................................ 97
Appendix A: RPL Building Schematics with Accident and Detector Locations ...... 99
Appendix B: CAS Component Descriptions............................................................... 102
Technical Description of the Comparator Panel ................................................................................ 102
Technical Description of the Radiation Detectors ............................................................................. 102
Appendix C: Material Definitions for Codes.............................................................. 106
Appendix D: Schedule of Deliverables ........................................................................ 115
Appendix E: Assumptions Used in the CAS Design of RPL ..................................... 116
Modeling Assumptions .......................................................................................................... 116
Translation notes ................................................................................................................... 118
Appendix F: MCNP5 Input Decks .............................................................................. 119
References ...................................................................................................................... 235

vi
List of Figures

Figure 1. Design process flow sheet ................................................................................ 24
Figure 2. UNCSR dose reduction factors for various shield thicknesses ........................ 29
Figure 3. UNCSR sample slide rule for U(93.2)O -(NO ) @ H/X=500 ........................ 30
2 3 2
Figure 4. Experimental setup for the NIST Sphere Benchmarks..................................... 55
Figure 5. 0.02 rad arcs for the outlying MAC’s in the basement of RPL ........................ 61
Figure 6. 0.02 rad arcs for the outlying MAC’s in the first floor of RPL ........................ 62
Figure 7. RPL Basement shown with modeled accident locations and the existing
detector placement ................................................................................................... 64
Figure 8. RPL First floor shown with modeled accident locations and the existing
detector placement ................................................................................................... 65
Figure 9. RPL Second floor layout .................................................................................. 66
Figure 10. Standard concrete material definition of 2.3g/cc density. .............................. 70
Figure 11. Graph of the total cross-section of 113Cd ........................................................ 78
Figure 12. Neutron energy spectrum for the spontaneous fission of 252Cf ...................... 80
Figure 13. Neutron energy spectrum grouped into 4eV and 20 MeV energy bins for the
spontaneous fission of 252Cf plotted on a log scale ................................................. 81
Figure 14. Existing calibration spectrum ......................................................................... 82
Figure 15. Average neutron energy spectrum during the Minimum Accident of Concern
grouped into 4eV and 20 MeV energy bins ............................................................ 83
Figure 16. Existing NCD calibration setup ...................................................................... 84
Figure 17. Revised NCD calibration setup with the added HDPE .................................. 86
Figure 18. Modified calibration spectrum grouped into 4eV and 20 MeV energy bins .. 87
Figure 19. RPL Basement showing accident locations and NCD locations .................... 99
Figure 20. RPL First Floor showing accident locations and NCD locations ................. 100
Figure 21. RPL Second Floor showing accident locations, no NCD are located on this
floor ....................................................................................................................... 101

vii
List of Tables

Table 1. Experimental normalized fission rates for 235U and 239Pu ................................. 56
Table 2. MCNP5 Computational results with comparison to experimental results ......... 57
Table 3. Plutonium minimum accident scenario data ...................................................... 58
Table 4. 252Cf calibration source information .................................................................. 73
Table 5. Detector counts for each MAC location in RPL ................................................ 76
Table 6. As modeled MAC locations in RPL .................................................................. 77
Table 7. Corresponding Data Used in the Histograms .................................................... 88
Table 8. Comparison of deterministic transport results to standard Monte Carlo results 89
Table 9. Detector counts for preliminary sensitivity analysis for maximum loading
within the facility .................................................................................................... 91
viii