ML033630768

Annual Operating Report for the Penn State Breazeale Reactor for July 1, 2002 Through June 30, 2003

ML033630768
Person / Time
Site:	Pennsylvania State University
Issue date:	12/09/2003
From:	Sears C Pennsylvania State Univ, University Park, PA, Univ of Pennsylvania
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
FOIA/PA-2004-0200
Download: ML033630768 (174)

Text

PENNSTATE Radiation Science and Engineering Center (814) 865-6351 Fax: (814) 863-4840 College of Engineering The Pennsylvania State University Breazeale Nuclear Reactor Building University Park, PA 16802-2301 Annual Operating Report, FY 02-03 PSBR Technical Specifications 6.6.1 License R-2, Docket No. 50-5 December 9, 2003 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555

Dear Sir:

Enclosed please find the Annual Operating Report for the Penn State Breazeale Reactor (PSBR). This report covers the period from July 1, 2002 through June 30, 2003, as required by technical specifications requirement 6.6.1. Also included are any changes applicable to 10 CFR 50.59.

A copy of the Forty-Eighth Annual Progress Report of the Penn State Radiation Science and Engineering Center is included as supplementary information.

Sincerely yours C. Frederick Sears Director, Radiation Science and Engineering Center Enclosures tlf cc. E. J. Pell D. N. Wormley L. C. Burton E. J. Boeldt M. Mendonca T. Dragoun Aoao College of Engineering An Equal Opportunity University

PENN STATE BREAZEALE REACTOR Annual Operating Report, FY 02-03 PSBR Technical Specifications 6.6.1 License R-2, Docket No. 50-5 Reactor Utilization The Penn State Breazeale Reactor (PSBR) is a TRIGA Mark III facility capable of 1 MW steady state operation, and 2000 MW peak power pulsing operation. Utilization of the reactor and its associated facilities falls into two major categories:

EDUCATION utilization is primarily in the form of laboratory classes conducted for graduate and undergraduate students and numerous high school science groups. These classes vary from neutron activation analysis of an unknown sample to the calibration of a reactor control rod. In addition, an average of 2500 visitors tour the PSBR facility each year.

RESEARCH/SERVICE accounts for a large portion of reactor time which involves Radionuclear Applications, Neutron Radiography, a myriad of research programs by faculty and graduate students throughout the University, and various applications by the industrial sector.

The PSBR facility operates on an 8 AM - 5 PM shift, five days a week, with an occasional 7 AM - 7 PM or 8 AM - 12 Midnight shift to accommodate laboratory courses or research/service projects.

Summary of Reactor Operating Experience - Tech Specs requirement 6.6.1 .a.

Between July 1, 2002 and June 30, 2003, the PSBR was critical for 745 hours0.00862 days <br />0.207 hours <br />0.00123 weeks <br />2.834725e-4 months <br /> or 2.9 hrs/shift subcritical for 414 hours0.00479 days <br />0.115 hours <br />6.845238e-4 weeks <br />1.57527e-4 months <br /> or 1.6 hrs/shift used while shutdown for 523 hours0.00605 days <br />0.145 hours <br />8.647487e-4 weeks <br />1.990015e-4 months <br /> or 2.1 hrs/shift not available 59 hours6.828704e-4 days <br />0.0164 hours <br />9.755291e-5 weeks <br />2.24495e-5 months <br /> or 0.2 hrs/shift Total usage 1742 hours0.0202 days <br />0.484 hours <br />0.00288 weeks <br />6.62831e-4 months <br /> or 6.8 hrs/shift The reactor was pulsed a total of 124 times with the following reactivities:

< $2.00 10

$2.00 to $2.50 80

> $2.50 34 The square wave mode of operation was used 59 times to power levels between 100 and 500 KW.

Total energy produced during this report period was 458 MWH with a consumption of 24 grams of U-235.

Unscheduled Shutdowns - Tech Specs requirement 6.6.1 .b.

The two unplanned shutdowns during the July 1, 2002 to June 30, 2003 period are described below.

On September 5, 2002, a DCC-X Watchdog Scram was received during a reactor startup.. An investigation indicated that the watchdog scram was caused by a failure of the IOBC card in DCC-X.

1

PSBR Annual Operating Report, FY 02-03 On October 17, 2002, the reactor was at 1 MW with a sample in the central thimble when 35 minutes into a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> run, the reactor tripped. Fission Chamber Power High indications were noted on both RSS and DCC-X when trends were reviewed. A transient was also noted on the Power Range gamma channel. No cause was found, but the sample degassing or bubbles traveling through the central thimble were considered possible causes.

Major Maintenance With Safety Significance - Tech Specs requirement 6.6.1 .c.

No major preventative or corrective maintenance operations with safety significance have been performed during this reporting period.

Major Changes Reportable Under 10 CFR 50.59 - Tech Specs requirement 6.6.1 .d.

Facility Changes -

November 13, 2002 - A building water supply pressure transmitter and reactor control room monitoring panel were placed into service. The alarm set-point assures that the reactor operator would be aware if 100 gpm of building water was not available as pool fill.

Procedures -

Procedures are normally reviewed biennially, and on an as needed basis. Changes during the year were numerous and no attempt will be made to list them.

New Tests and Experiments -

None Radioactive Effluents Released - Tech Specs requirement 6.6.1 .e.

Liquid There were no planned liquid effluent releases under the reactor license for the report period Liquid radioactive waste from the radioisotope laboratories at the PSBR is under the University byproduct materials license and is transferred to the Radiation Protection Office for disposal with the waste from other campus laboratories. Liquid waste disposal techniques include storage for decay, release to the sanitary sewer as per 10 CFR 20, and solidification for shipment to licensed disposal sites.

Gaseous Gaseous effluent Ar-41 is released from dissolved air in the reactor pool water, air in dry irradiation tubes, air in neutron beam ports, and air leakage to and from the carbon-dioxide purged pneumatic sample transfer system.

The amount of Ar-41 released from the reactor pool is very dependent upon the operating power level and the length of time at power. The release per MVWH is highest for extended high power runs and lowest for intermittent low power runs. The concentration of Ar-41 in the reactor bay and the bay exhaust was measured by the Radiation Protection staff during the summer of 1986.

Measurements were made for conditions of low and high power runs simulating typical operating cycles. Based on these measurements, an annual release of between 347 mCi and 1053 mCi of Ar-41 is calculated for July 1, 2002 to June 30, 2003, resulting in an average concentration at ground level outside the reactor building that is 0.6 % to 1.7 % of the effluent concentration limit 2

PSBR Annual Operating Report, FY 02-03 in Appendix B to 10 CFR 20.1001 - 20.2402. The concentration at ground level is estimated using only dilution by a 1 m/s wind into the lee of the 200 m 2 cross section of the reactor bay.

During the report period, several irradiation tubes were used at high enough power levels and for long enough runs to produce significant amounts of Ar-41. The calculated annual production was 381 mCi. Since this production occurred in a stagnant volume of air confined by close fitting shield plugs, much of the Ar4 1 decayed in place before being released to the reactor bay. The reported releases from dissolved air in the reactor pool are based on measurements made, in part, when a dry irradiation tube was in use at high power levels; some of the Ar-41 releases from the tubes are part of rather than in addition to the release figures quoted in the previous paragraph.

Even if all of the 381 mCi were treated as a separate release, the percent of the Appendix B limit given in the previous paragraph would still be no more than 2.3 %.

Production and release of Ar-41 from reactor neutron beam ports was minimal. Beam port #7 has only three small (1/2 inch diameter) collimation tubes exiting the port and any Ar-41 production in these small tubes is negligible. Beam port #4 has an aluminum cap installed inside the outer end of the beam tube to prevent air movement into or out of the tube as the beam port door is opened or closed. The estimated Ar-41 production in beam port #4 for all beam port operations is 26 mCi. With the aforementioned aluminum cap in place, it is assumed that this Ar-41 decayed in place. Radiation Protection Office air measurements have found no presence of Ar-41 with the beam port cap in place.

The use of the pneumatic transfer system was minimal during this period and any Ar-41 release would be insignificant since the system operates with CO-2 as the fill gas.

Tritium release from the reactor pool is another gaseous release. The evaporation rate of the reactor pool was checked previously by measuring the loss of water from a flat plastic dish floating in the pool. The dish had a surface area of 0.38 ft2 and showed a loss of 139.7 grams of water over a 71.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> period giving a loss rate of 5.11 g ft 2 hr- 1 . Based on a pool area of about 395 ft2 the annual evaporation rate would be 4680 gallons. This is of course dependent upon relative humidity, temperature of air and water, air movement, etc. For a pool 3 H concentration of 41948 pCi/l (the average for July 1,2002 to June 30, 2003) the tritium activity released from the ventilation system would be 743 pCi. A dilution factor of 2 x 108 ml s 1 was used to calculate the unrestricted area concentration. This is from 200 m 2 (cross-section of the building) times 1 m s (wind velocity). These are the values used in the safety analysis in the reactor license. A sample of air conditioner condensate a previous year showed no detectable 3 H. Thus, there is probably very little 3 H recycled into the pool by way of the air conditioner condensate and all evaporation can be assumed to be released.

3 H released 743 RC Average concentration, unrestricted area 1.17 x 10-13 [,Ci/mi Permissible concentration, unrestricted area 1 x 10-7 tLCi/ml Percentage of permissible concentration 1.18 x 10-4 %

Calculated effective dose, unrestricted area 5.89 x 10-5 mRem Environmental Surveys - Tech Specs requirement 6.6.1 .f.

The only environmental surveys performed were the routine TLD gamma-ray dose measurements at the facility fence line and at control points in two residential areas several miles away. This reporting year's measurements (in millirems) tabulated below represent the July 1, 2002 to June 30, 2003 period.

3

PSBR Annual Operating Report, FY 02-03 3rd Qtr '02 4th Otr '02 1st Otr '03 2nd Qtr '03 Total Fence North 25.8 24.8 25.1 23.4 99.1 Fence West 22.7 22.9 24.3 25.3 95.2 Fence East 26.7 22.9 21.0 26.0 96.6 Fence South 24.1 25.7 21.9 25.8 97.5 Control 25.5 24.0 23.0 21.7 94.2 Control 22.8 20.7 20.7 19.8 84.0 Personnel Exposures - Tech Specs requirement 6.6.1 .g.

No reactor personnel or visitors received an effective dose equivalent in excess of 10% of the permissible limits under 10 CFR 20.

4

48TH ANNUAL PROGRESS REPORT PENN STATE RADIATION SCIENCE

& ENGINEERING CENTER July 1, 2002 to June 30, 2003 Submitted to:

United States Department of Energy and Penn State By:

C. Frederick Sears (Director)

Kenan Unlu (Assoc. Director)

Terry L. Flinchbaugh (Manager, Operations & Training)

Susan K. Ripka (Administrative Assistant, Editor)

Angela D. Pope (Staff Assistant, Co-Editor)

Radiation Science and Engineering Center Penn State University Park, PA 16802 December 2003 Contract DE-AC07-94ID- 13223 Subcontract C88-101857 U.ED.ENG 04-43 Penn State is committed to affirmative action, equal opporunity, and the diversity of its workforce

TABLE OF CONTENTS Page PREFACE - T.L. Flinchbaugh I. INTRODUCTION - T.L. Flinchbaugh ....................... ........................ I II. PERSONNEL - T.L. Flinchbaugh ................................................... 4 III. REACTOR OPERATIONS - T.L. Flinchbaugh ............ ....................... 8 IV. GAMMA IRRADIATION FACILITY - C.C. Davison ......... .................. 12 V. EDUCATION AND TRAINING - C.C. Davison ............ ..................... 16 VI. NEUTRON BEAM LABORATORY - K. Unlu ............ ....................... 25 VII. RADIONUCLEAR APPLICATIONS LABORATORY - T.H. Daubenspeck, 41 K. Unlu ...................................................................................

VIII. ANGULAR CORRELATIONS LABORATORY - G.L. Catchen .57 IX. LOW PRESSURE INTEGRAL TEST FACILITY - L.E. Hochreiter, 59 S.M. Cetiner.

X. ENVIRONMENTAL HEALTH AND SAFETY - D. Bertocchi .71 XI. RADIATION SCIENCE AND ENGINEERING CENTER RESEARCH AND SERVICE UTILIZATION A. Penn State University Research and Service Utilizing the Facilities of the 75 Penn State Radiation Science & Engineering Center - A.D. Pope .

B. Other Universitites, Organizations and Companies Utilizing the Facilities 144 of the Penn State Radiation Science & Engineering Center -

T.L. Flinchbaugh.

APPENDIX A. Faculty, Staff, Students, and Industries Utilizing the Facilities of the 145 Penn State Radiation Science & Engineering Center -

T.L. Flinchbaugh.

APPENDIX B. Formal Tour Groups - A.D. Pope .148 ii

TABLES Tables Page

1. Personnel.................................................................. 5

2. Reactor Operation Data ............................................... 10

3. Reactor Utilization Data ............................................... 1

4. Summary of Current Gamma Irradiation Facilities ................. 14

5. Cobalt-60 Utilization Data ........................................ 14

6. Academic Instruction Data ........................................ 20 FIGURES Figures Page

1. Organization Chart ............................................... 7

2. Gamma Irradiation Uses & Examples .............................................. 15

3. Educational Institutions Visiting the RSEC ...................................... 21 iii

PREFACE Administrative responsibility for the Radiation Science and Engineering Center (RSEC) resides in the College of Engineering. Overall responsibility for the reactor license resides with the Vice President for Research and Dean of the Graduate School. The reactor and associated laboratories are available to all Penn State colleges for education and research programs. In addition, the facility is made available to assist other educational institutions, government agencies, and industries having common and compatible needs and objectives, providing services that are essential in meeting research, development, education, and training needs.

The Penn State University Radiation Science and Engineering Center's Forty-Eighth Annual Progress Report (July 2002 through June 2003) is submitted in accordance with the requirements of Contract DE-AC07-94ID- 13223 between the United States Department of Energy and Bechtel (BWXT Idaho), and their Subcontract C88-101857 with the Pennsylvania State University. This report also provides the University administration with a summary of the utilization of the facility for the past year.

Numerous individuals are to be recognized and thanked for their dedication and commitment in this report, especially Angela Pope and Sue Ripka who co-edited the report. Special thanks are extended to those responsible for the individual sections as listed in the table of contents and to the individual facility users whose research summaries are compiled in Section XI.

iv

Introduction

,.r

.} %

A F .

I. INTRODUCTION MISSION In conducting this mission in pursuit of the stated vision, the following activities are highlighted The mission of the Penn State Radiation Science and Engineering Center (RSEC), in partnership among the numerous accomplishments reported with faculty, staff, students, alumni, government, in the pages that follow:

and corporate leaders, is to safely utilize nuclear

• The fiscal year began with the arrival of Dr.

technology to benefit society through education, Kenan Unlu as senior scientist/associate research, and service. director for research. Dr. Unlu was previously the director of the Cornell University Research Reactor. This is the first The RSEC facilities have a diverse and time in many years that a faculty member is dedicated staff with a commitment to safety, devoted primarily to research using the excellence, quality, user satisfaction, and nuclear facilities as an effort to increase education by example and teaching. facility utilization. A major National Science Foundation research initiative in the area of dendrochronology (the science of dating VISION events and variations in environment in former It is the vision of the faculty and staff of the periods by comparative study of growth rings Radiation Science and Engineering Center to in trees and aged wood) was brought with become a leading national resource and make him from Cornell along with valuable neutron significant contributions in the following areas: activation analysis counting equipment. In addition to neutron activation analysis, other research areas of interest to Dr. Unlu are Safety-Actively promote nuclear and neutron depth profiling and the development personal safety in everything we do. of a cold neutron beam facility.

Education-Develop and deliver

• Considerable faculty and staff effort was innovative educational programs to advance rewarded when DOE issued INIE societal knowledge of nuclear science and (Innovations in Nuclear Infrastructure and engineering through resident instruction and Education) grants. Penn State'sjoint proposal continuing education for students of all ages with Purdue University, the University of and their educators. Illinois and the University of Wisconsin Research-Expand leading edge research received approximately $1.97 million, with that increases fundamental knowledge of Penn State's share approximately $1 million.

nuclear science and engineering particularly The Penn State consortium was ranked second in the area of materials research applications and received the largest dollar amount by far of nuclear techniques. of the six grants awarded. Currently, DOE plans to continue the grant program for four Service-Expand and build a diverse array additional years. The objective of the INIE of services and users by maintaining program is to strengthen the nation's university excellence, quality, user satisfaction, and nuclear engineering programs through efficient service to supplement university innovative use of the university research and funding and enhance education and research. training reactors. In the first year of the grant the following was accomplished:

1

• The Room 2 laboratory/classroom was totally

• Efforts began to lay the groundwork for the refurbished and equipped with state-of-the future development of a cold neutron beam art computer work stations and audio-visual and expansion of the neutron beam laboratory.

equipment Code studies are being done to determine if current beam ports need to be supplemented with a new beam port and how beam ports can interface with a heavy water tank and the reactor. The current neutron beams are also being characterized to assure that the development of new beams will notjeopardize the work being done with the current beams.

• Drs. Jack Brenizer, Dr. Kenan Unlu and Dr.

Matthew Mench of the Department of Mechanical and Nuclear Engineering began a major research project using neutron radioscopy and neutron radiography for investigation of fuel cells for a major automotive company. Several other companies used the beam facilities for radiography and radioscopy projects, some of which were associated with the space shuttle program.

• A refurbished GammaCell was ordered during the '02-'03 fiscal year. The upgraded Cobalt-60 loading will decrease irradiation

• A project to upgrade the reactor control times by a factor of ten, providing much system hardware and software continued better service for campus users. The present during the year but was delayed by a strike GammaCell was very heavily used during the by the engineers at AECL, the project vendor.

year resulting in longer than desired wait The project was near completion at the time times for irradiations. (The new GammaCell of the strike. An installation of the new system arrived early in the new '03-'04 fiscal year). is expected near the mid-point of the new

• A chopper system was developed to fiscal year.

characterize the neutron beam used for

• The neutron irradiation of semi-conductors for radiography and radioscopy. As part of the commercial, military, and space applications INIE grant, this system will be available for loan to other research reactors. continued at a very healthy pace.

• Mini-grants were awarded on a competitive

• The use of neutron radioscopy and neutron basis to Penn State and non-Penn State transmission as a research and service tool individuals submitting proposals to use the to industry continued at a very high level Penn State Radiation Science and during the year with increasing interest by Engineering Center facilities. companies who fabricate boron containing metals used in the nuclear industry. Efforts are underway to upgrade the software and hardware associated with this work.

2

• Income from service work done for industrial

• In light of concem for terrorist activities that could users was used to continue the support of three be directed against university research reactors, Ph.D. graduate students in the nuclear contnuing efforts were made in expanding the engineering department. Two students are total scope of facility security. Additional working in the area of modeling the Penn State attention to security issues is expected to TRIGA reactor core and developing better continue, both self-directed and in response to computer code tools for fuel depletion NRC guidance. The staff is meeting the challenge tracking and core loading designs. The third of providing security without compromising the student is working in the area of thermal- education and research mission of the reactor hydraulic modeling of the TRIGA core. facility.

• Numerous high school, Penn State, and non-

• The coming year should see a continued high Penn State college/university groups level of use by industrial customers, increased participated in educational programs at the university related research activities, RSEC under the direction of Candace Davison significant progress in the development of during the year. In many cases, experiments computer code tools to model the TRIGA core, teaching nuclear concepts were performed. installation of new reactor control system The RSEC also supported educational events hardware and software, and the completion such as Boy Scout and Girl Scout merit badge of a much needed lobby expansion project.

programs. The facility hosted more than 2,400 visitors during the fiscal year. A complete list of groups hosted is presented in Appendix B.

ePhase IV of Dr. Robert Edwards' DOE funded project "Monitoring and Control Research Using a University Research Reactor" was completed. This involved considerable staff efforts in interfacing Dr. Edwards' control system with the Penn State Low Pressure Integral Test Facility. Significant staff assistance was needed to upgrade the test loop facility.

• Increased reactor usage for university courses continued this year as multiple sessions were needed in the NE 451 and NE 450 laboratory courses. An increased emphasis on graduate students taking NE 444, Nuclear Reactor Operations, resulted in more reactor usage during the year.

3

Personnel II. PERSONNEL Many undergraduate students worked in work-study Frank Buschman resigned his position as reactor or wage payroll positions during the year. Jaclyn operator intern on Aug. 16,2002, upon completion Adamonis, Kaydee Kohlhepp, Melisa Marcy, of his undergraduate degree in nuclear engineering and Rachel Slaybaugh, and Doug Yocum assisted his entry into graduate school at Penn State. David Candace Davison in facility educational programs Werkheiser resigned his position as a senior reactor for high school students. Margaret Sapovchak operator intern on April 3,2003 upon his completion assisted Mac Bryan as computer support specialist of a master's degree in nuclear engineering and his while Jeremy Myers was on leave. Mustafa Cetiner acceptance ofemployment with the Nuclear Regulatory assisted Mac Bryan in computer support areas. Commission.

Jared Hoover and Brian Pye assisted Dr. Kenan Unlu on research projects. Tristan Schaefer assisted Mark Grieb, engineering aide/reactor operator, the reactor staff on a standards qualification project resigned his position during January 2003.

for an industrial customer.

Dr. Kenan Unlu, former director of the Cornell Erin Carlin and Joe Bonner worked wage payroll University Ward Center for Nuclear Sciences, was in assisting Candace Davison with educational hired as senior scientist/associate director for programs. research and professor of nuclear engineering effective July 1,2002.

Several promotions occurred during the fiscal year.

Dr. C. Frederick Sears was promoted from director/

affiliated associate professor to senior scientist/

director of RSEC. Gary M. Morlang was promoted from reactor operations engineer/supervisor to senior supervisor/reactor engineering operations.

Sue Ripka was promoted from administrative assistant II to administrative assistant III. Wendy Donley was promoted from staff assistant VI to staff assistant VII.

The following changes to the membership of the Penn State Reactor Safeguards Committee (PSRSC) were effective on Jan. 1,2003. Theodore Dalpiaz (manager, nuclear maintenance, Pennsylvania Power and Light Susquehanna Steam Electric Station) completed his second term on the committee and was not eligible for Undergraduate Bret Rickert was hired to begin training re-appointment. Gordon Robinson (professor as a reactor operator on Oct. 31,2002, and received emeritus, nuclear engineering, Penn State) was re-his senior reactor operator's license in June 2003. appointed to a second term. Ira McMaster (retired Undergraduate Adam Koziol was hired to begin training deputy director, Penn State Breazeale Nuclear as a reactor operator on Dec. 2,2002, and received Reactor) was re-appointed to a second term, Frederick his senior reactor operator's license in June 2003. Both Eisenhuth (senior engineer, Pennsylvania Power and Bret and Adam had previous nuclear navy experience. Light Susquehanna Steam Electric Station) was appointed to his first term.

4

TABLE 1 Personnel Faculty and Staff Title Francis X. Buschman Reactor Operator Intern (resigned)

Jack S. Brenizer Professor, Nuclear Engineering

• • Mac E. Bryan Research Engineer/Supervisor, Reactor Operations Gary L. Catchen Professor, Nuclear Engineering

• • Thierry H. Daubenspeck Activation and Irradiation Specialist/Supervisor, Reactor Operations

• • Candace C. Davison Research and Education Specialist/Supervisor, Reactor Operations Chanda C. Decker Reactor Operator Intern Wendy R. Donley Staff Assistant VII

• • Terry L. Flinchbaugh Manager, Operations and Training Mark P. Grieb Engineering Aide (resigned)

• • Brenden J. Heidrich Research Assistant

• • Adam W Koziol Reactor Operator Intern

• • Alison R. Portanova Research and Service Support Specialist-/Supervisor, Reactor Operations Jana Lebiedzik Research Support Technician I

• • Gary M. Morlang Senior Supervisor/Reactor Engineering Operations Randy A. McCullough Instrumentation Engineer Jeremy Myers Computer Support Specialist Angela D. Pope Staff Assistant V Paul R. Rankin Radiation Measurement Technician

• • Bret M. Rickert Reactor Operator Intern Susan K. Ripka Administrative Assistant HI

• • C. Frederick Sears Senior Scientist/Director of RSEC Kenan Onlu Senior Scientest, Associate Director for Research

• • Dave L. Werkheiser Reactor Operator Intern (resigned)

Licensed Operator

• • Licensed Senior Operator Technfical Service Staff Ronald L. Eaken Machinist A Sally Thomas Staff Support Wage Payml/Wodstud Jaclyn Adamonis Melissa Marcy Joe Bonner Brian Pye Erin Calin Margaret Spaovchak Mustafa Cetiner Tristan Schaefer Jared Hoover Rachel Slaybaugh Kaydee Kohlhepp Doug Yocuni 5

TABLE 2 Penn State Reactor Safeguards Committee R. C. Benson Professor and Department Head, Mechanical and Nuclear Engineering, Penn State E. J. Boeldt Manager of Radiation Protection, Environmental Health and Safety, Penn State

• T. C. Dalpiaz Manager, Nuclear Maintenance, Pennsylvania Power and Light Susquehanna Steam Electric Station

• • F. Eisenhuth Senior Enginer, Pennsylvania Power and Light Susquehanna Steam Electric Station L. Hochreiter, Chairman Professor, Mechanical & Nuclear Engineering, Penn State K.Ivanov Associate Professor in Charge of Fuel Management, Penn State T. A. Litzinger Professor and Director of Leonhard Center, Penn State

• • • I. B. McMaster Retired Deputy Director, Penn State Breazeale Nuclear Reactor

• • • G. E. Robinson Professor Emeritus, Nuclear Engineering, Penn State C. F. Sears Ex-Officio, Director, Penn State Radiation Science and Engineering Center R. Tropasso Manager of Nuclear Design, Exelon

• Served through January 1, 2003

• • Initial Appointment January 1, 2003

• ** Re-Appointed for a second term effective January 1, 2003 6

RADIATION SCIENCE & ENGINEERINGCENTER PERSONNEL CHART FIGURE I

t I

I C I; 1 f I I ReacrI Reactor i

Operations I

4%Mw I .

A'

&- L, I

\

I 9

I. REACTOR OPERATIONS Research reactor operation began at Penn State The PSBR core, containing about 7.5 lbs. of in 1955. In December 1965, the original 200 Uranium-235, in a non-weapons form, is kW reactor core and control system was operated at a depth of approximately 18 ft. in a replaced by a more advanced General Atomics pool of demineralized water. The water TRIGA core and analog control system. TRIGA provides the needed shielding and cooling for stands for Training, Research, Isotope the operation of the reactor. It is relatively Production, built by General Atomic Company. simple to expose a sample by positioning it in The new core was capable of operation at a the vicinity of the reactor at a point where it steady state power level of 1000 kW with will receive the desired radiation dose. A pulsing capabilities to 2000 MW for short variety of fixtures and jigs are available for such (milliseconds) periods of time. positioning. Various containers and irradiation tubes can be used to keep samples dry. A In 1991, the reactor console system was pneumatic transfer system offers additional upgraded to an AECL/Gamma-Metrics dual possibilities. A heavy water tank and neutron digital/analog control system. This system beam laboratory provide for neutron provided for improved teaching and research transmission and neutron radioscopy activities.

capabilities and features a local area network Core rotational, east-west, and north-south whereby console information can be sent to movements provide flexibility in positioning the laboratories and emergency support areas. core against experimental apparatus.

Utilization of the Penn State Breazeale Reactor In normal steady state operation at 1000 kW, (PSBR) falls into four major categories: the thermal neutron flux available varies from approximately I x 1013 n/cm2 /sec at the edge of Educational- utilization is primarily in the form the core to approximately 3 x 1013 n/cm2 /sec in of laboratory classes conducted for graduate and the central region of the core.

undergraduate degree candidates and numerous high school science groups. These classes will vary from the irradiationand analysis of a sample, non- When using the pulse mode of operation, the destructive examinations of materials using neutrons peak flux for a maximum pulse is approximately or x-rays, or transient behavior of the reactor to the 6 x 1016 ncm2 /sec with a pulse width of 15 calibration of a reactor control rod.

msec at half maximum.

Research - involves radionuclearapplications, neutron radiography, gamma irradiation, a myriad Support facilities include hot cells, a machine of research programs by faculty and graduate shop, electronic shop, darkroom, laboratory students throughout the University, and various space, and fume hoods.

applications by the industrial sector:

Training - programs for PSBR Reactor Operations staff. STATISTICAL ANALYSIS Service - involves radionuclear applications, neutron transmission measurements, radioscopy, Tables 2 and 3 list Reactor Operation Data semiconductor irradiations, isotope production, and and Reactor Utilization Data-Shift Averages, other applications by the industrial sector. respectively, for the past three years. In Table 2, the Critical time is a summation of the hours the reactor was operating at some 8

power level. The Subcritical time is the total receives compensation for Industrial Research hours that the reactor key and console instru- and Service. University research and service mentation were on and under observation, less includes both funded and non-funded research, the Critical time. for Penn State and other universities. The Instruction and Training category includes all Subcritical time reflects experiment set-up time formal university classes involving the reactor, and time spent approaching reactor criticality. experiments for other University and high school groups, demonstrations for tour groups and in-house reactor operator training.

The Number of Pulses reflects demands of undergraduate labs, researchers, and reactor operator training programs. Square Waves are Part C statistics, Users/Experimenters, reflects used primarily for demonstration purposes for the number of users, samples and sample hours public groups touring the facility, as well as per shift. Part D shows the number of eight researchers and reactor operator training hour shifts for each year.

programs.

INSPECTIONSANDA UDITS The Number of Scrams Planned as Part of Experiments reflects experimenter needs. On Dec. 5, 2002, an audit of the PSBR was Unplanned Scrams from Personnel Action are conducted to fulfill a requirement of the Penn due to human error. Unplanned Scrams State Reactor Safeguards Committee charter as Resulting from Abnormal System Operation are described in the PSBR Technical related to failure of experimental, electronic, Specifications. The audit was conducted by electrical, or mechanical systems. Sean O'Kelley, associate director, Nuclear Engineering Teaching Laboratory, the University of Texas at Austin. The reactor staff Table 3, Part A, Reactor Usage, describes total implemented changes suggested by that report, reactor utilization on a shift basis. The all of which exceed NRC requirements.

summation of Hours Critical and Hours Subcritical gives the total time the reactor console key is on. Hours Shutdown includes time for instruction at the reactor console, experimental setup, calibrations or very minor maintenance that occupies the reactor console but is done with the key off. Significant maintenance or repair time spent on any reactor component or system that prohibits reactor operation is included in Reactor Usage as Reactor Not Available.

Part B gives a breakdown of the Type of Usage in Hours. The Department of Mechanical and Figure 1. Alison Portanova, senior reactor operator &

Nuclear Engineering and/or the reactor facility Chanda Decker, reactor operator intern.

9

TABLE 2 Reactor Operation Data July 1, 2000 - June 30, 2003 00-01 01-02 02-03 A. Hours of Reactor Operation

1. Critical 864 1028 745

2. Subcritical 375 424 414

3. Fuel Movement 0 40 0 B. Numberof Pulses 104 124 124 C. Number of Square Waves 48 52 59 D. Energy Releases (MWH) 472 648 458 E. Grams U-235 Consumed 24 33 24 F. Scrams

1. Planned as Part of Experiments- 11 9 16

2. Unplanned - Resulting From a) Personnel Action 0 1 0 b) Abnormal System Operation 1 2 2

-, A_~,Il

- - de - f 10

TABLE 3 Reactor Utilization Data Shift Averages July 1, 2000 - June 30, 2003 00-01 01-02 02-03 A. Reactor Usage

1. Hours Critical 3.2 3.8 2.9

2. Hours Subcritical 1.4 1.6 1.6

3. Hours Shutdown 1.6 2 2.1

4. Reactor Not Available 0.4 0.2 0.2 TOTAL HOURS PER SHIFT 6.6 7.5 6.8 B. Type of Usage - Hours

1. Industrial Research and Service 3.4 3.5 3.0

2. University Research and Service 0.6 1.3 0.8

3. Instruction and Training 1 1.3 1.6

4. Calibration and Maintenance 1.6 1.3 1.4

5. Fuel Handling 0 0.1 0 C. Users/Experiments

1. Numberof Users 2.6 3.1 2.9

2. Pneumatic Transfer Samples 0.3 1.6 0.2

3. Total Number of Samples 3.2 4.6 3.2

4. Sample Hours 2.9 3.4 2.5 D. Number of 8 Hour Shifts 270 271 255 11

4 -~~~~~~~~~~~~~~~~~~~~~~~~~~I Gtamma- 8fL 4

! t-I.)  ; W.

• t t

¢ I

d-i~i t

I!j ld -

hA 11 'N l~~~~~~~~

IV GAMMA IRRADIATION FACILITY The Gamma Irradiation Facility includes in-pool GammaCell 220 Dry Irradiator irradiators and a dry shielded GammaCell 220 irradiator. The Gamma Irradiation Facility is The GammaCell 220 dry irradiator has a dose rate designed with a large amount of working space considerably higher than that currently available in around the irradiation pool. This is where the the RSEC in-pool irradiators. Other advantages GammaCell 220 is located along with of the GammaCell 220 include a large irradiation workbenches and the usual utilities. chamber (approximately 6 inches diameter and 7.5 inches high), an automatic timer to move the sample In-Pool Irradiators chamber away from the source and the ability to conduct in-situ testing of components during For the in-pool irradiators, the source rods are irradiation.

stored and used in a pool 16 feet by 10 feet, filled The David Sarnoff Research Center in Princeton, with 16 feet of demineralized water. The water New Jersey donated the GammaCell 220 to Penn provides a shield that is readily worked through State in July 1995. The maximum dose rate is and allows great flexibility in using the sources. Due summarized in Table 4.

to the number of sources and size of the pool, it is possible to set up several irradiators at a time to Funding for an upgraded GammaCell 220 Excel vary the size of the sample that can be irradiated, irradiator with a higher central dose rate has been requested. Funding for the new Gammacell is or vary the dose rate. Experiments in a dry environment are possible by use of either a vertical through the U.S. Department of Energy I.N.I.E.

tube or by a diving bell type apparatus. Four grant. The upgraded Gammacell is expected to different irradiation configurations have been used be delivered during the month of July 2003.

depending on the size of the sample and dose rate required. The advantage of the in-pool irradiators is that the dose rate can be varied in a manner which is optimal for agricultural and life science research.

In March 1965, the University purchased 23,600 curies of Cobalt-60 in the form of stainless steel clad source rods to provide a pure source of gamma rays. In November 1971, the University obtained from the Natick Laboratories 63,537 curies of Cobalt-60 in the form of aluminum clad source rods. These source rods have decayed through several half-lives, and the dose rates available are summarized in Table 4. The dose rates listed for the pool irradiator tubes reflect a new source configuration as of June 27, 2003, which increased the number of sources around the 6 inch tube. Figure 1. Tristan Schaeffer and Candace Davison insert a sample into the GammaCell 220 Dry Irradiator.

12

Use of Gamma IrradiationServices The use of the Gamma Irradiation facility has been increasing steadily. There was a 23 percent increase in the number of sample hours performed in the Gammacell compared to last year. The utilization of the Gammacell was near capacity (approximately 84 percent) for full-time use. The number of irradiations and sample exposure time in the pool was due to several new research projects on campus, WISER projects and radiochromic calibration. Several departments on campus utilized the services of the gamma irradiation facility for a variety of purposes. Figure 2 shows some of the variety of samples and purposes for irradiations this past year. Other University and pre-college educational institutions utilized the gamma irradiation facility through research projects or the Reactor Sharing Program.

This information is outlined in the Research and Service utilization section and in Appendix A. Table 5 compares the past three years' utilization of the Cobalt-60 Irradiation Facility in terms of irradiation time and number of irradiations. Samples requiring over 10 Megarads for cross-linking purposes were typically divided into 5, 10 or 20 Megarad irradiations to allow for other users.

13

TABLE 4 PMMMW _ ._ . .

Facility Maximum Dose Rate Sample Limitations in Krads/hour*

North Tube 37.0 Must be less than 6 inches in diameter 6-inch South Tube -24 Must be less than 3 inches in diameter 3-inch 10-inch Depends on source array Cylinder approximately 10 inches in Chamber diameter by 12 inches in height GammaCell 162.1 Cylinder approximately 6 inches in Dry Cell diameter by 7.5 inches in height Irradiator

• as of 7/1/2003 TA RI E r

UV-UI Pool Gamma- Pool Gamma- Pool Gamma-I--- A;.-. n o11 n o11 r ^11 A. Time Involved (Hours) _ ___

1.Setup/Admin. Time 15 55 17 89 16 71

2. Total Sample Hours 1557 3800 394 5667 1835 7352 B. Numbers Involved ___ _

1. Total Irradiations 45 162 33 227 _ 84 223

2. Samples Containers Run' 542 615 204 1200 _ 958 959

3. Different Experimenters 12 21 5 29 _ 11 25

4. Configurations Used 3 N/A_ 4 N/A 4 N/A NOTE: The reporting was changed starting in last year's report to include the total number of irradiations conducted and the daily averages were eliminated.

'Note that each sample container may contain multiple samples and that multiple samples may be run together in one batch.

Gamma Irradiation Uses and Examples Genetic Chanmes Sterilization Class Proiects and Demonstrations:

Medical & Laboratory Products Poinsettias Fruit Flies Beef Table Salt Patties Cells Mushrooms Soil & Leaves for Environmental Testingj D.S Cross-Linkin! of Polymers Carnations Food Irradiation Bread

=s I I FIGURE2

I-EducI I-'

I l

777::- ,t

• /l I,,

Lw-- , -- -

,do

d P... --

W 1.0 r-lis I

• I I

V EDUCATIONAND TRAINING During the past year, Penn State's RSEC was used Police Training:

for a variety of educational services, in-house training, formal laboratory courses, and many In December 2002 and January 2003, a total of continuing education programs and tours. The 37 University police personnel were given training continuing education programs and tours sessions by C. C. Davison at the RSEC to ensure accommodated more than 2,400 visitors. familiarity with the facilities and to meet Nuclear Regulatory Commission requirements.

Operator Taining:

Governor's School:

The RSEC operating staff has maintained reactor operator competence and safe facility operation through training and requalification. During a two- The seventeenth session of the Pennsylvania year training cycle, theory, principles, regulations Governor's School for Agricultural Sciences and actions needed for the safe operation of the (PGSAS) was held at Penn State's University Park reactor facility are covered. Training sessions campus during the summer 2002. Sixty-four high during the year include lectures, exercises, and other school scholars participated in the five-week activities. In-house reactor operator requalification program at Penn State. The Governor's School consisted of an oral examination on abnormal for Agricultural Sciences includes introduction and events and emergency procedures given by G.M. experience in many different agricultural disciplines.

Morlang and an operating test given by T.L. The participants of the Govemor's School received Flinchbaugh during October and November 2002. a tour of the Reactor facility with some time for Adam Koziol and Bret Rickert, operator interns, hands-on instruction. Candace Davison, Doug passed their NRC senior reactor operator license Yocum, Erin Carlin, Frank Bushman, and Chanda examinations in June 2003. Decker provided the instruction and tours for the PGSAS.

Reactor Sharing:

The University Reactor Sharing Program is sponsored by the U.S. Department of Energy. The purpose of this program is to increase the availability of the university nuclear reactor facilities to non-reactor-owning colleges and universities.

The main objectives of the University Reactor Sharing program are to strengthen nuclear science and engineering instruction, and to provide research opportunities for other educational institutions including universities, colleges, and pre-college schools.

Figure 1.Candace Davison and Bret Rickert do Reactor Operator Training.

16

More than 500 students and teachers from over The RSEC staff utilized the facilities and equipment twenty different educational institutions and two to provide educational opportunities and tours for colleges came to the RSEC for experiments and student and teacher workshops, many of which instruction (see map). Candace Davison, Jaclyn were conducted as part of other programs on Adamonis, Kaydee Kohlhepp, Melisa Marcy, campus. These programs are typically conducted Douglas Yocum, and Joseph Bonner were the main through the Penn State College of Engineering, the instructors for the program. Chanda Decker, Women in Science and Engineering (WISE)

Kaydee Kohlhepp, and Dianna Hahn along with Institute, the Continuing and Distance Education other mechanical and nuclear engineering students Program, Campus Admissions, and the University provided information about their major during Relations offices. The student programs included:

student visits. Thierry Daubenspeck, Jana the VIEW program, Women in Science and Lebiedzik, Mac Bryan, Brenden Heidrich, and Dr. Engineering (WISE) week, Pennsylvania Junior Jack Brenizer provided instruction and technical Academy of Sciences, and other programs assistance for experiments. associated with campus activities. Several different activities for Girl Scouts and Boy Scouts were conducted at the facility. More than 75 Boy Scouts and 26 Girl Scouts participated in activities at the facility sponsored by the Penn State student ANS chapter. A short report on the Boy Scout program is included.

Job-shadowing was another means by which some pre-college students learned about nuclear applications. The students spent from half a day to several days shadowing staff and faculty at the facility to enhance their understanding of nuclear technology and careers. One student from State College High School spent several sessions at the facility learning about neutron radiography. This A joint research project with faculty and students student was very interested in how a working fuel from the University of Pittsburgh at Greensburg cell could be imaged using this technique.

was conducted during the academic year. Dr. Tim Savisky, assistant professor of natural sciences, and Dr. Ted Zaleskiewicz, professor of physics, along with Hollie Ramaley, an undergraduate student, participated in the project. The main goal was to investigate heavy metal contamination in the environment through Neutron Activation Analysis of tree ring samples.

17

Nuclear Science & Technology Course intended to provide students practical experience A one-week course on Nuclear Science and in application of radiation science and technology.

Technology was conducted from July 15-19, Cory Trivelpiece participated this past academic 2002. John Vincenti was the coordinator of the year. A short summary is included in the research course which was held again based upon the section.

success of the previous course. Five teachers attended the workshop and received free Geiger Counters through a grant from the American Nuclear Society. Candace Davison provided instruction on radiation, reactor basics, nuclear applications and conducted experiments at the facility for the participants.

Undergraduate Research Scholarships:

Undergraduate students can conduct research at the facility and receive scholarship funding through the facility Undergraduate Research Scholarship grant. The purpose of the scholarship is to encourage undergraduate students to participate in investigation and research relating to reactor safety, operations, and utilization. Participation is Tours:

In addition to the full or half-day programs with experiments, educational tours were conducted for students, teachers, and the general public. All groups, including those detailed in the above sections, who toured the facility are listed in Appendix B. The RSEC operating staffalong with i t- the mechanical and nuclearengineering department

0. 14 conducted several open house events for the Parent and Family Weekend, the general public

[i' and potential undergraduate or graduate students.

More than 450 people participated in Open F \ House and "Spend a Day" experiences.

I~

18

Academic Instruction:

The RSEC supports academic instruction by providing information and expertise on nuclear technology topics, tours and experiments conducted at the facility and through the availability of specialized equipment and classroom/laboratory space.

The joint instructional experience for students in the IE 408W (Human Factors) course was continued in the fall and spring semesters. The students were instructed on reactor basics so that they could understand the control signals and input along with an overview of the control console in the classroom. The students then went into the control room where they observed a start-up and the operator's actions. They also observed the reactor while at power. Feedback from the students was very positive concerning their real-world experience.

The reactor classroom was utilized as the base of instruction for several courses including; Freshman seminar (Fall 2002 and Spring 2003), NUCE 450, and NUCE 451. The TRIGA reactor and Cobalt-60 irradiation facilities were used by several nuclear engineering courses and courses in other departments of the university as outlined in Table 6.

19

TABLE 6 Academic Instruction Data

• ~~~

- - mm IM99 REM Sumnmer 2002 SCIED 498B - Nuclear Science and J. R. Vincenti 5 4 Technology Workshop C. C. Davison Summner 2002 NUC E 444 C. F. Sears 1 33 Fall 2002 ESAC 433H C. F. Sears 12 1 Fall 2002 STS 150 J. Pearce 15 1 Fall 2002 NUCE 0O1S - Freshman Seminar J. S. Brenizer 37 4 Fall 2002 Nuc E 301 - Fundamentals of RM. Edwards 27 1 Reactor Physics Fall 2002 Nuc E 401 - Introduction to Nuclear L Hochreiter 17 2 Enginerng Fall 2002 NucE 451 - Experiments Reactor R. M. 14 23 Physics Edwards Fall 2002 Food Science 413 - Science & R B. Beelman 26 2 Technology of Plant Food Fall 2002 Food Science /STS 105 V. Chang 15 1 Fall 2002 AG 150S - Agricultural Seminar D. Olver/L. 23 1 Sordillo Fall 2002 E 408 W Human Factors L Newman 88 6 Fall 2002 ME 30H D. A. 20 Santavicca Spring 2003 NUCE 001S - Freshman Seminar J. S. Brenizer 20 2 Spring 2003 NucE 444 - Nuclear Reactor C. F. Sears 3 70 Operations Spring 2003 NucE 450 - Radiation Detection and J. S. Brenizer 12 7 Measurement Spring 2003 ENGR PSY - 432 Engr. Psychology A. Peck 18 1 Spring 2003 IE 408 W Human Factors L Newman 74 5 Spring 2003 ME 30 D. A. 20 1 Santavicca Spring 2003 CHEM 036 (Penn State Altoona) C.S. Reed 10 1 Spring 2003 CE 597D J. B. Matson 8 1 20

Educational Institutions Visiting the RSEC Kane Area HS Grove City College Berwick HS University of Pitt-Greensburg St. Mary' s HS j Eastern Lebanon County MS Brockway HS ~7 Hollidaysburg HS Nativity High School Central HS Grier School Greensburg-Salem HS PJSAHS Spring Grove HS Ligonier Valley HS 2 Tyrone MS Red Lion Christian School Marion Center HS State College Area Schools Punxsutawney HS State College Charter School Williamson Sr. HS Nittany Valley Charter Schoc Figure3

Atomic Energy Merit Badge Program This year, due to the overwhelming response of applications received in the first weeks of registration, Penn State ANS decided to offer this program twice in February.

On Feb. 8, 2003, 5 Troops, totaling 47 scouts earned their Atomic Energy Merit Badge.

Twenty-three Penn State students volunteered 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of their time to run this program. A total of 70 people participated in this day. About 20 Penn State student volunteers helped in the Feb. 22, 2003 session which served 4 troops and 28 scouts.

Prior to the workshop dates Penn State ANS members attended a Boy Scouts Council meeting to announce the opening of registration for this years workshop. Packets consisting of a letter Public perception of nuclear technology is often and a registration form were distributed to riddled with fear and misconception. As the interested troop leaders. Following this meeting nuclear accidents like Three Mile Island and troops emailed or mailed in registration forms Chernobyl slip into the past and we move to Penn State ANS. Within the first week of toward a more technological future, the door to registration Penn State ANS had reached their change public perception of nuclear technology limit. A second session was announced to is opening. One way to help alleviate this accommodate the larger number of interested perception barrier is through outreach programs scouts. This session quickly filled. About 120 that focus on public education.

scouts applied for the program in all. However, due to the size of the facility and time constraints The scouting programs present the ANS with PSU ANS could only accept the first 9 troops, the opportunity to reach out to the youth of today totaling 75 scouts between both sessions.

and the future of tomorrow. The Penn State student ANS first sponsored an Atomic Energy Merit Badge Workshop for the Boy Scouts in October 1995. The first Nuclear Science and Technology Patch Workshop for Girl Scouts followed in March 1996. Both workshop programs were offered annually until spring 1999 when, despite the success of the programs, the annual workshops stopped for a few years.

This successful outreach was reestablished with the Penn State student ANS when the next workshop was given in March 2001. Since then the program has been run once per year during the spring semester.

22

Beginning in January, Kaydee Kohlhepp and Activities Craig Matos met weekly to discuss the schedule of events. In addition to the merit badge The first five activities are required for all requirements Penn State ANS came up with a scouts to complete.

few additional activities to enforce important concepts being presented. 1. Explain/define each of the following: alpha particle, atom, background radiation, beta One week prior to the workshop volunteers met particle, curie, fallout, half-life, ionization, to have a final meeting. At this meeting duties isotope, neutron, neutron activation, nuclear were assigned and packets of information were reactor, particle accelerator, radiation, made to hand out to each scout. radioactivity, roentgen, and x-ray.

The requirements for a scout to earn their 2. Make three-dimensional models of the atoms Atomic Energy Merit Badge are set by the Boy of the three isotopes of hydrogen. Show Scouts of America National Council and are neutrons, protons, and electrons. Use these listed below. Penn State ANS volunteers models to explain the difference between atomic facilitated discussions and activities so that all weight and number.

badge requirements were met during a single day. 3. Make a drawing showing how nuclear fission happens. Label all details. Draw a second picture showing how a chain reaction could be started. Also show how it could be stopped.

V K Show what is meant by a "critical mass."

&R a I

_~~~~~~~~~~~~~~~~~~ 4. Tell who five of the following people were and explain what each of the five discovered in the field of atomic energy: Henri Becquerel, Niels Bohr, Marie Curie, Albert Einstein, Enrico Ferm-i, Otto Hahn, Ernest Lawrence, Lise Meitner, Wilhelm Roentgen, and Sir Ernest Rutherford. Explain how any one person's discovery was related to one other person's work.

5. Draw and color the radiation hazard symbol.

Explain where it should be used and not used.

Tell why and how people must use radiation or radioactive materials carefully.

23

6. Do any three of the following (Items marked with an

• met the Atomic Energy Merit Badge requirements and were completed the day of the workshop):

a. Build an electroscope. Show how it works. Put a radiation source inside it. Explain any difference seen.

b. Make a simple Geiger counter. Tell the parts.

Tell which types of radiation the counter can spot.

Tell how many counts per minute of what radiation you have found in your home.

c. Build a model of a reactor. Show the fuel, the control rods, the shielding, the moderator, and any cooling material. Explain how a reactor could be used to change nuclear energy into electrical energy or make things radioactive. g. Visit a place where X rays are used. Draw a floor plan of the room in which it is used. Show where

• d. Use a Geiger counter and a radiation source. the unit, the person who runs it, and the patient Show how the counts per minute change as the would be when it is used. Describe the radiation source gets closer. Put three different kinds of dangers from X rays.

material between the source and the detector.

Explain any differences in the counts per minute.

• h. Make a cloud chamber. Show how it can be Tell which is the best way toshield people from used to see the tracks caused by radiation. Explain radiation and why. what is happening.

e. Use fast-speed film and a radiation source. Show the principles of autoradiography and radiography.

Explain what happened to the films. Tell how someone could use this in medicine, research, or industry.

• f. Using a Geiger counter (that you have built or borrowed), find a radiation source that has been hidden under a covering. Find it in at least three other places under the cover. Explain how someone could use this in medicine, research, agriculture, or industry.

24

-i -w

.1

• t If

'-II

'Ii . etfrr II La I

) *;:

'-I' 11 -ar---Ndw~~~~~

VI. NEUTRON BEAM LABORATORY The Neutron Beam Laboratory (NBL) is one of fuel, only one beam port is at the centerline of the the experimental facilities at the RSEC. Well- core active area, four beam ports are five inches collimated beams of neutrons, thermalized by a below the centerline and two are eleven inches D20, are passed into the NBL for use in various below the centerline (below the active fuel region).

neutron beam techniques. When the reactor core Because of these inherited limitations only two is placed next to a D 2 0 tank and graphite beam ports are currently being used. BP #4 reflector assembly near the beam port locations, with 3 x 107 ncm2 sec flux at the aperture is thermal neutron beams become available for used for research, primarily neutron radiography 2

neutron transmission and neutron radiography and radioscopy, and BP #7 with - 105 n/cm sec measurement from two of the seven existing neutron flux is used for service activities beam ports. In steady state operation at 1MW, involving neutron transmission measurements.

2 the thermal neutron flux is lxlO13 n/cm sec at Since the BP #4 collimators are primarily the edge of the core and 3x 1013 n/cm 2 sec at the designed and optimized for neutron radiography central thimble. The Penn State Breazeale and radioscopy measurements, it is not possible Reactor (PSBR) can also pulse with the peak to obtain desired results for other flux for maximum pulse - 6x1016 n/cm 2 sec with measurements. We are currently trying to use a pulse width of 15 msec at half maximum. BP #4 for all of our research projects. Due to space limitations, we must shuffle delicate Current Status of PSBR Beam Ports: research equipment around. More importantly, each project or experimental techniques require The PSBR has seven beam ports. The locations a special or dedicated neutron beam with of the beam ports within the biological shield different collimations and neutron flux. With and elevations of the beam ports with respect the current set-up and arrangement we can only to the reactor pool floor are given in Figure 4 perform meaningful research for neutron and Figure 5. The internal diameter of the beam radiography and radioscopy.

ports are four inches for BP #3 and BP #5; five inches for BP #1 and BP #7; and six inches for BP #2, BP #4 and BP #6. The center of BP #4 New Beam Ports and Beam Hall Expansion:

is sixty five inches from the pool floor while BP #1, BP #3, BP #5 and BP #7 are sixty inches Due to inherited design issues with the current and BP #2 and BP #6 are fifty four inches from arrangement of beam ports and reactor core-the pool floor. With the current setup of reactor- moderator assembly, the development of core-moderator assembly only BP #4 is at the innovative experimental facilities utilizing centerline of the TRIGA core. (Active length of neutron beams is extremely limited. Therefore, TRIGA fuel is 15"). BP #1, 3, 5 and 7 are five a new core-moderator location in PSBR pool inches below the centerline of the core and BP #2 and beam port geometry needs to be determined and 6 are eleven inches below the centerline of in order to build useful neutron beam facilities.

the core. The core grid assembly does not permit A study is underway with the support of DOE-lowering the core more than the current INIE funds to examine the existing beam ports arrangement. When the PSBR reactor was built for neutron output and to investigate new core MTR type fuel elements with active length of 24" and moderator designs that would be accessible were used. With the MTR fuel the beam port by new additional beam ports. The MCNP arrangement did not limit the maximum neutron modeling of both cases is near completion. We output. In the mid 60's the PSBR was converted envision a location in the pool where reactor core from MTR type to TRIGA type fuel. With TRIGA 25

would be "parked" and surrounded by a

• Development of a single-disk neutron chopper moderator (DO or graphite). New beam ports for time-of -flight spectroscopy at Penn State would be geometrically aligned with the core- (see Research and Service Utilization Section, moderator assembly for optimum neutron output. page 129). This work resulted in several presented papers and a M. Sc. thesis.

The new core-moderator and beam port arrangement requires expansion of the existing beam laboratory in order to place

• Neutron depth profiling studies at the Penn instrumentation, neutron guides, and beam State University Breazeale Nuclear Reactor catcher, etc. Both the new design of core- (NDP description and result of preliminary moderator/beam port arrangement and the NDP measurement at RSEC is given below).

expansion of the current beam laboratory to form a beam hall are strongly related. The new beam hall will have a total of 4,000 sq ft of

• Analyzing soft error rates in semiconductor experimental area (the existing area of - 1,000 memories and field programmable gate sq ft plus a new additional area of -3,000 sq errays (see Research and Service Utilization ft). Research areas envisioned for RSEC's new Section, page 92).

beam port/beam hall design are as follows.

Neutron Depth Profiling facility for depth vs.

concentration measurements, impurity

• Neutron radiography measurements for water determination of He-3 and B-10 in transport in an operating polymer electrolyte semiconductors, metal and alloys; Cold Neutron fuel cell (see Research and Service Utilization Source and Cold Neutron Prompt Gamma Section, page 106).

Activation Analysis for neutron focusing research, materials characterization and determination of impurities in historically or

• Continuous frame capture analysis software technologically important material; Neutron project at Radiation Science and Powder Diffraction for structural determination Engineering Center (see Research and of materials, and a Triple Axis Diffractometer Service Utilization Section, page 13).

to train students on neutron diffraction and perform preliminary structural determinations of materials.

• Modeling ofexisting beam-port facility at Penn State University Breazeale Nuclear Reactor Projects utilizing the NBL during the year included by using MCNP (see Research and Service the following: Utilization Section, page 94).

Study of a loop heat pipe using neutron radiography (see Research and Service

• Investigation of preferential flow of water in Utilization Section, page 121). Bettis sand samples using real time neutron Atomic Power Laboratory used the RSEC radiography. Collaborative work with beginning in June 2000, to evaluate the Cornell University, Ward Center for Nuclear operational characteristics of an ammonia Sciences.

loop heat pipe. This work resulted in several presented papers and a Ph D dissertation.

26

• Testing of primary oxygen tanks for NASA's space suits to determine locations of hydrated corrosion products on the internal surfaces using neutron radiography and radioscopy. Service provided to Hamilton Sundstrand, a United Technologies Company.

• Neutron transmission measurements and neutron radioscopy were conducted for borated metals and other borated materi-als for Northeast Technology Corporation, Eagle-Picher Industries, Transnuclear, NY, and Transnucleaire, France.

• Radiographic and radioscopic techniques were demonstrated as part of several student projects; including demonstration of neutron and x-ray imaging for the Governor's School students and students enrolled in the freshman seminar (NucE OQS). The students assembled plaques containing a variety of objects and predicted their neutron & x-ray attenuation characteristics. Experiments with neutron & x-ray radiography confirmed their predictions.

27

97.62 FIGURE4 PSBR beam port layout with D20 tank.

28

I I I 22" 1 20" 1 24" 1 24" 1 20" 22" I I - I I I I I I I I TRIGA I I I I

- I - - 1 Fuel - - - - - - L - - -

I I Length _ I T #7 I I I I 4 I I #1

- - - - - - - - b - - - -P I--

I

1. 6 II I 4+

I II I

I I I I II 65" I II I

I II 60" I ID I I I I I 54" 1 I I

I I I 1 1 I

I I 1 1 I I I I

I Reactor Pool floor I , , _

I al F///,~~~~~~

FIGURE5 Elevations of PSBR beam ports with respect to the reactor pool floor.

29 C

,16 )-

fl A..... -

NEUTRON DEPTH PROFILING (NDP) STUDIES AT PENN STATE BREAZEALE NUCLEAR REACTOR

Participants:

K. Unli, Prof.

S. Qetiner, Grad. Student J. Hoover, Undergrad. Student Services Provided: Neutron Beam Laboratory Sponsor: U.S. Department of Energy, under Nuclear Energy Engineering Research (NEER) grant INTRODUCTION Neutron Depth Profiling (NDP) is a near-surface-analysis technique to measure the spatial distribution of certain isotopes of technological importance in any substrate. The NDP technique was originally developed by Ziegler et al. [] in 1972, and later thoroughly investigated by Biersack et al. [2 3i. The basis of NDP is the irradiation of a sample with thermal or sub-thermal neutrons and the subsequent release of charged particles due to neutron induced exoergic charged particle reactions. Neutrons interact with the nuclei of isotopes '0 B, He, Li, Be and 22 Na etc., and release mono energetic charged particles, e.g. alpha particles or protons, and recoil atoms. Figure is an illustration of this reaction for '0 B, and Table 1 gives a detailed listing of other relevant NDP reactions.

On 2 He 0 1472 keV A_

SD0 _ > > nOU 478 keV Li\

8L X 840 keV Figure . Neutron-boron reaction that creates charged particles, 7Li and 4He.

30 C

The charged particles travel outward and lose energy by numerous interactions with the electrons of the host matrix. Measuring the residual energy of the charged particles or recoil atoms and knowing the stopping power of the host matrix allow for the determination of the depth profile of the isotope of interest inside the matrix. The reader is recommended to refer K. Unlu et al [4] for a comprehensive discussion.

Figure 2 presents an example to the correlation between the range and the initial energy of alpha particles in silicon. The dotted red lines indicate the energy of alpha particles coming out of the '°B (n, a) Li reaction: Vertical line is the initial energy, which is 1472 keV and the horizontal line is the range of alpha particles in elemental silicon. What this tells us is that alpha particles that are from 11B (n, a) 7 Li reaction travel 5 gm on the average within the silicon matrix until they ultimately come to a full stop.

AB<>2rp5 33

/',Y NN,,0o 1I . .. . 4/........

.......... X-------i'- ~L

---

- -l i d

.rtial Energy of af particles from El(n a.)3Li reaction

~r-t-' i**~~

ii i-----i -- i _ Ch ir--------------

Figure 2. The plot gives an example to the mapping between the energy and the theoretical range of alpha particles in silicon. The data is generated by SRIM 2003 software made available by Ziegler et.al.

PRINCIPLES OF NDP Figure 3 shows the schematic of a conventional NDP setup and Figure 4 shows the block diagram of a conventional NDP setup. The detector used in NDP setup is operated in vacuum (around 10-6 torr) to eliminate alpha particle attenuation while they travel from the sample to the detector surface. Figure 5 shows the picture of the vacuum chamber that encloses the sample and the detector, and the electronics.

During the experiment, neutrons enter the chamber through thin Al windows. Neutrons hit the sample and interact with '0B isotopes creating charged particles, alpha and 7 Li. Then some of the charged particles move towards the detector and hit the detector surface resulting in a small charge signal. This signal is then sent to the preamplifier where it is amplified and converted into a voltage signal. After that it is amplified again in the amplifier. The analog signal is then converted into a digital signal in an ADC unit (Analog-to-Digital Converter) and the digital signal is displayed on the computer. The instrumentation can also be seen in Figure 5 next to the vacuum chamber.

31 C 04

Table 1. Useful NDP reactions Energy of Emitted Cross Detection Element Reaction Abundance Taiet Particles Section Limits (keV) (barns) (atoms/cm2) 3 He He (n, p) 3H 0.00014 stable 572 191 533 1.01 x 1014 6

Li Li (n, a) 3H 7.5 stable 2055 2727 940 5.71 x 1014 7

Be Be (n, p) Eli [2.5 x 104]t 53 d 1438 207 48000 1.12 x 1013 B 'B (n, a) Li 19.9 stable 1472 840 3837 1.40 x 1014 N 4N (n, p) 14 C 99.6 stable 584 42 1.83 2.93 x 1017 7

0 1O (n, a) "C 0.038 stable 1413 404 0.24 2.24 x 1018 22 Na* 2'Na (n, p) Ne [4.4x 10 5t 2.6y 2247 103 31000 1.73 x 103 33 30 S S (n, a) Si 0.75 stable 3081 411 0.19 2.83 x 1018 35 Cl CI (n, p) 35s 75.8 stable 598 17 0.49 1.10 x 1018 40 K K(n, p) Ar 0.012 stable 2231 56 4.4 1.22x l07 59 Ni Ni (n, a) 5 6 Fe [1.3 x 10201+/- 80,000y 4757 340 12.3 4.37 x 1016

- Radioactive species

§- Detection limit is based on 0.1 count/sec with 0.0078 Sr detector solid angle, and a neutron intensity of 3.0 x 108 s-1 at the exit of the radial beam port of the Cornell TRIGA Mark II reactor at 500 kW.

t - These values are in atoms/mCi.

NDP TECHNIQUES There are two ways to correlate the measured energy of the particle to the depth the particle is created: by directly measuring the particle energy through pulse-height analysis, or by measuring the intervals between the time that charged particles are created and the time they hit the surface of the detector through time base analysis.

The first technique will be referred to as ConventionalNDP, and the latter as 77me-of-Flight NDP (TOF-NDP)throughout this text.

32

In the conventional NDP, one directly measures the particle energy. Once the energy spectrum is taken, using the stopping power correlations pertinent to the material of interest, each energy bin in the spectrum is matched to the corresponding depth of isotope of interest that underwent the charged particle reaction.

The energy difference from the initial particle energy is an indication of how far these particles traveled within the matrix; in other words, how deep the isotope of interest reside. Figure 3 and Figure 4 illustrate the experimental setup for the conventional NDP.

____~~'11 Aluminum Window Electrical Feed- hru Vacuum Gauge Feed-thru Figure 3. The schematic of the NDP experimental setup Figure 4. Conventional NDP diagram 33

Figure 5. NDP setup at Breazeale Nuclear Reactor: electronic instrumentation panel (left) and the vacuum chamber (right)

Time-Of-Flight technique does not directly measure particle energy. Rather than measuring energy, one can measure the time intervals between the time that the charged particles are created and the time they hit the surface of the detector. In order to do that, one needs two separate detectors: one for the start signal that is created by prompt electrons, which are theoretically instantly created when a charged particle reaction takes place, and another for stop signal created by charged particles or recoil nuclei. The time difference between the two signals gives a measure of how fast particle traverses, in other words how energetic it is, with the well-known formula:

Ef =mHeV -mHe,)

where E is the energy of alpha particles when they leave the sample, x is the distance of the detector to the sample, and t is the time interval between the alpha particles are created and they hit the detector surface.

Time-Of-Flight NDP block diagram is given in Figure 6.

34

Preamplifier Detector 1 1 GHz Amplifier and Timing Discriminator High-Voltage Power Supply F1'Z.1 Computer with Mulfi-channel Analyzer icosecond ime Analyzer Preamplifier Detector 2 1 GHz Amplifier and Timing Discriminator Nanosecond Delay Figure 6. Block diagram of Time-of-Flight NDP setup APPLICATIONS OF NDP The NDP technique has diverse applications in microelectronics, optical signal processing, surface modification technologies, and new technology alloy development.

These applications involve the measurement of the behavior of the light elements such as helium, boron, lithium, beryllium, etc. in various materials. The majority of these applications involve boron depth profiling in semiconductor materials. Two of the most common applications of NDP are briefly described below.

1. 3He in alloys The radiation damage in alloys due to 3 He implantation is an important issue that can be investigated by using the NDP technique. Helium can modify material properties because, when introduced into materials, it tends to nucleate as small gas clusters in lattice defects. If helium fluence is increased the small gas clusters combine and form gas bubbles. Gas bubbles may recombine and create a pressurized cavity 35

beneath the material surface. When the pressure of the cavity is high enough, it can form blisters. Rupturing of these blisters causes surface flaking or exfoliation.

Pressurized helium gas bubbles inside materials may also cause cracks. Formation of cracks and propagation of cracks to the bulk can ultimately compromise the structural integrity of materials. The shape of the depth profile gives information about possible microstructural changes that occur in an alloy. For example, the differences in spatial distribution of implanted Helium in a near-surface region and across interfacial boundaries can significantly affect the Helium release phenomenon.

When a thermal neutron strikes the sample with 3 He, the 3 He (n, p) 3H reaction takes place. From the proton energy spectrum, one can determine the 3 He distribution within the sample. The energy spectrum can be converted to depth profile using the stopping power correlations and corresponding counts are translated to isotopic concentration profile. K. Unld et al 151gives a more detailed explanation on 3 He analysis in alloys.

2. '0B in MicroelectronicsMaterials The application of NDP in microelectronics has been an important topic due to the extensive use of boron in semiconductor device fabrication. Some of the important applications for semiconductor industry are:

• . Study of boron distributions in semiconductor materials as a function of wafer treatment.

• Investigation of boron transport in semiconductor materials, especially across oxide surfaces.

• Study of boron concentration in microelectronics passive layers as it affects melting temperatures.

• Study of boron doses of semiconductor materials for dose calibration of commercial ion implant systems.

Please refer to K. NlW et al [6] for further discussion on this issue.

EXPERIMENTS PERFORMED AT PENN STATE UNIVERSITY BREAZEALE NUCLEAR REACTOR

1. Conventional NDP Experiments with Intel BorophosphosilicateGlass Sample Borophosphosilicate glass (BPSG) is used as an insulating layer on high-density integrated circuits.

The thickness of the boron layer in BPSG is an important factor in the production of multilayer circuits. A more detailed discussion can be found in K. Unild, et al [7.

Figure 7 illustrates the results of an NDP experiment performed with an Intel Borophosphosilicate glass wafer. The energy spectrum of the alpha peak plotted in the top figure is converted into the atomic concentration versus isotope depth from the surface of the matrix. Note that the measured 36

particle energy -the horizontal axis in the top figure- carries information about the distance alpha particles traveled in the matrix before they hit the surface of the detector, i.e. the more energy they have the closer they are to the surface.

Figure 7. Experimental data for Intel Borophosphosilicate glass wafer (top), and concentration vs. projectile depth (bottom).

At the top figure, blue plot represents the original measurement during the experiment. This signal has significant noise content in it. The background noise can be fitted to a polynomial, as presented with the green data. If this content is subtracted from the measurement, one obtains the net count spectrum as plotted in red at the top figure.

The bottom figure is obtained by using the net count spectrum in the NDP calculations. As we discussed earlier, particle energy is translated to isotope depth and net count into isotope concentration in the calculations.

The origin of the horizontal axis denotes the surface of the wafer. The distribution tends to disperse at the edges because of the diffusion mechanism, predominantly into the silicon wafer. The figure also illustrates a rough interpretation of the thickness of the Borophosphosilicate glass layer from the isotope distribution. The measured thickness is in good agreement with the actual thickness of the layer.

The resolution of the measurement system for this sample is about 20 nm around in 500-nm depth.

37

2. Conventional NDP Experiments with AMD I 0B Implanted Silicon Wafer Ion implantation is the most frequent and widely practiced method of doping silicon during semiconductor device fabrication. The typical fabrication plant has a series of ion implanters set up to introduce a dopant like boron. The dose of these dopants need to be within a limited tolerance and desired distribution profile in order for reliable device performance. Another important issue is that these multiple implanters must provide the same dose/profile over a period of time in order to yield consistent products. The accurate characterization of the implanted dose is therefore very important.

Figure 8 shows the results of an NDP experiment for a 120 keV '0 B implanted AMD silicon wafer at a total dose of 2.0 x 1016 atoms/cm 2 . As with the Borophosphosilicate glass wafer, energy spectrum is converted into isotope depth, and the number of counts into 10B concentration in the matrix.

Figure 8. Experimental measurements with AMD wafer (top), and concentration profile vs.

projectile depth (bottom).

The background noise removal is achieved with the same procedure explained for the Borophosphosilicate glass wafer. Once the net count is obtained, it is used in the NDP calculation. In a profile of an implanted isotope, one expects a Gaussian-like distribution as shown at the bottom figure. The slight skewness or asymmetry of the peak is an artifact of the nonlinearity of the scattering process -in terms of energy-within solids.

The resolution in the close proximity of the peak is found to be around 20 nm.

38 CAO~

PROJECTIONS ON NDP EXPERIMENTS Our group already reproduced the conventional NDP experiments performed at University of Texas at Austin and Cornell University before, as presented in Figure 7 and Figure 8. We are working on replicating the same experiments, among others, with the TOF-NDP technique. TOF-NDP at Penn State University is continuing to develop. Figure 9 shows the detailed schematics of the latest NDP setup. We expect that TOF NDP will provide up to a ten times better resolution than the conventional NDP, which will make the depth vs. concentration measurements of ultra shallow junction devices possible. We think that this improvement will have a significant impact on silicon industry as the dimension of micro devices gets miniatunzed every day.

Figure 9. Time-Of-Flight NDP schematics ACKNOWLEDGEMENT This project is sponsored by U.S. Department of Energy under Nuclear Energy Engineering Research (NEER) grant.

39

REFERENCES

1. F. Ziegler, G.W. Cole, and J.E.E. Baglin, J. Appl. Phys., Vol. 43 (1972) 3809.

2. J. P. Biersack, D. Fink, in S. Datz, B. R. Appleton, C. D. Moak, (Eds), Atomic Collisions in Solids, (Plenum Press, New York, 1975) p. 737.

3. D. Fink, J.P. Biersack, H. Liebl, in H. Ryssel, H. Glawischnig (Eds), Ion implantation:Equipment and Techniques, (Springer-Verlag, Berlin, 1983) p.3 1 8 .

4. K. UnlO and B.W. Wehring, Nucl. Instr. And Meth. Phys. Res. A, 353, (1994) 402.

5. K. UnlW and D. H. Vincent, "Helium-3 behavior in some Nickel-based Amorphous Alloys,"

Nuclear Science and Engineering, Vol. 110, No. 4, April 1992.

6. K. UnWi, M. Saglam, B. W. Wehring, "3 He and "0B Concentration and Depth Measurements in Alloys and Semiconductors using NDP," Nucl. Instr. and Meth. in Phys. Res. A 422 (1999) 885.

7. K. UnlU et al., IEEE Proc. 11 Int. Conf. on Ion Imp. Tech., Vol. 1, 1996, p 575.

40

I A16 I

• t.O I

~~~~~~~~~~~~~~~~~~~I

-~~~~~~~ .

abortory ma~~~~m%,

10 I

4~~~~~

UHTEC5 Aoltomaitc Si Ctww* g MOdg ASC 2 l m

VI. RADIONUCLEAR APPLICATIONSLABORATORY A. Service The RadionuclearApplications Laboratory (RAL) The facility performed 9 isotope production runs provides consulting and technical assistance to ofNa-24, Br-82 orAr-41 for industrial use during faculty, students, staff and scientists from the past fiscal year. As needed, the RAL is able to corporations, state and government agencies analyze and test chemicals not currently on our wishing to use radionuclear techniques in their approved list and during the past year tested and research projects. The majority ofthese projects approved another chemical for radioisotope involve neutron activation analysis; however, the production.

staff is also able to provide services in radioactive tracer techniques, radiation gauging, and isotope Penn State students and faculty members production for laboratory, radionuclear medicine continue to use the services offered by the RAL.

or industrial use. Analytical work was performed for graduate and undergraduate students in the Nuclear Engineering and the Anthropology departments.

Nuclear Engineering students use the RAL for various projects being performed at the RSEC.

The RAL assisted students from the Anthropology Department in characterizing various samples of obsidian and rhyolite using Neutron Activation Analysis (NAA). This analysis involves determining the concentrations ofspecific elements in various obsidian and rhyolite samples to identify the source of the samples. The obsidian samples originate from Central America and the rhyolite samples are collected in the United States. This is an on-going project that began years ago.

A redesign of our pneumatic transfer system (rabbit system) is being investigated which will be more flexible than the current system. An undergraduate mechanical/nuclear engineering During the past fiscal year, 502 semiconductor student, assisted by reactor staff, is designing irradiations were performed at the RSEC for the new system.

various companies. RAL personnel prepared devices for irradiation, calculated the 1-MeV Silicon Equivalent fluence received, and analylzed irradiated devices to determine the radioisotopes present. RAL personnel returned irradiated devices in accordance with NRC and DOT regulations.

41

VII. RADIONUCLEAR APPLICATIONSLABORATORY B. Research The improvement for some existing facilities using Staff and students ofthe Wiener Laboratory have DOE-INIE and RSEC funds at RAL is currently already prepared approximately three thousand underway. These include building a new neutron samples ofwood, each from a single year, for this activation analysis (NAA) facility with two study. A dedicated NAA system was built at automatic sample changers, four gamma Cornell's Ward Center for Nuclear Sciences for spectroscopy systems with high purity germanium this study with NSF and Cornell funds. Samples (HPGe) detectors, state-of-the-art data acquisition were activated at the core of Cornell's 500 kW and processing systems. A laboratory/classroom TRIGA Mark II research reactor and NAA for 36 students has been renovated for workshops measurements were performed using a and outreach activities. This laboratory has nine spectroscopy facility with automatic sample student benches each containing a computer that changer system. After Cornell's decision to close is connected to a spectroscopy system via the the Ward Center for Nuclear Sciences, the Internet and various other nuclear measurement prepared samples, gamma spectroscopy sytem, systems at RAL. Before and after pictures of and sample changer were transferred to Penn State, both NAA laboratory and student workshop Radiation Science and Engineering Center.

laboratory/classroom are given in Figures 1, Measurements will continue at Penn State using la, 2 and 2a respectively. the 1 MW Breazeale Nuclear Reactor. Please see details ofthis project in a paper given below.

The current main activity at RAL is a dendrochronology project. The objective of this study is to determine experimentally periods of global environmental stress during the past six thousand years using tree samples already collected and dated and neutron activation analysis (NAA). The result of this study will provide climate modelers with a much needed extended timeline. This study is the first coordinated dendrochemical study of a period longer than one hundred years, and the first study in the archaeologically important eastern Mediterranean. The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern I -- ftA Dendrochronology at Cornell University 4 1 archives over 40,000 individually-dated tree samples with 4.5 million rings from one hundred

.. k.

J.

X

"'N

" 'I nine forests in the eastern Mediterranean and Figure 1. Before picture of Neutron Activation former Soviet Union. These samples span most Analysis Laboratory.

of the period from 7000 BC to the present. All dendrochronogically dated samples at the Wiener Laboratory are available for this study.

42

Figure Ia. After picture of Neutron Activation Analysis Laboratory.

i~~ ~ --,912.

Figure 2. Before picture of Workshop Laboratory and Classroom.

Figure 2a. After picture of Workshop Laboratory and Classroom.

43

NEUTRON ACTIVATION ANALYSIS OFABSOLUTELY-DATED TREE RINGS:

IDENTIFYING CLINIATICALLY-SIGNIFICANT MARKER EVENTS IN HISTORYAND PREMISTORY

Participants:

K. Unlil, Prof.

P.I. Kuniholm, Prof. (Cornell University)

J. J. Chiment, Intructor (Cornell University)

D. K. Hauck, Grad. Student B. R. Pye, Undergraduate Student T. H. Daubenspeck, Activation & Irradiation Specialist Services Provided: Radionuclear Applications Laboratory Sponsor: Cornell University, NSF, and RSEC Abstract Uptake of metal ions by plant roots is a function of the type and concentration of metal in the soil, the nutrient biochemistry of the plant, and the immediate environment of the root. Uptake of gold (Au) is known to be sensitive to soil pH for many species. Soil acidification due to acid precipitation following volcanic eruptions can dramatically increase Au uptake by trees. Identification of high Au content in tree rings in dendrochronologically-dated, overlapping sequences of trees allows the identification of temporally-conscribed, volcanically-influenced periods of environmental change.

Ion uptake, specifically determination of trace amounts of gold, will be performed for dendrochronologically-dated tree samples. The concentration ofgold will be correlated with known environmental changes, e.g. volcanic activities, during historic periods. Several thousand wood samples will be scanned initially for gold. After this initial measurement, samples containing elevated levels of gold will be analyzed again for short and long half-life elements, e.g. silver, copper, etc., to investigate other elemental signatures ofenvironmental change. NeutronActivation Analysis (NAA) is the assay of choice for Au in organic material. The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology at Cornell University has archived over 40,000 individually-dated wood samples with 4.5 million rings. These samples span the period from 7000 BC to the present. Most of the dendrochronogicaly-dated samples present at the Wiener Laboratory are available for this project. Using samples already collected and dated and the NAA technique we propose to define periods of global environmental stress during the past six thousand years. This will provide modelers with a much-needed extended timeline. This project will be the first coordinated dendrochemical study of a period longer than one hundred years and the first study in the archaeologically important eastern Mediterranean.

44

Research Objectives The objective of this study is to determine experimentally periods of global environmental stress during the past six thousand years using tree samples already collected and dated and neutron activation analysis (NAA). The result of this study will provide climate modelers with a much-needed extended timeline. This study is the first coordinated dendrochemical study ofa period longer than one hundred years and the first study in the archaeologically important eastern Mediterranean. In addition, it may be possible to determine the precise dates of major prehistoric volcanic eruptions, e.g. Thera/Santorini.

Uptake of metal ions by plant roots is a function of the type and concentration of metals in the soil, nutrient biochemistry of the plant, and immediate environment of the root. Uptake of gold (Au) is sensitive to soil pH for many species'4. Soil acidification due to acid precipitation following volcanic eruptions may dramatically increase Au uptake. Volcanic aerosols from major eruptions stress plant communities in a variety of ways: darkness, acidity, increased or decreased rainfall. Plant stress invokes enzymatic antioxidant systems. Copper (Cu), an important trace nutrient in plants, is necessary for these systems. Plants do not discriminate in uptake among the Group b transition elements: Cu, silver (Ag), and Au. Once admitted to the plant Au is bound within the wood of the year and does not participate in biochemical reactions. Identification of high-Au tree rings in dendrochronologically-dated, overlapping sequences of trees may allow the identification-to the exact year-of temporally-conscribed, volcanically-produced periods of environmental change.

We have a model (Fig. 1) that links the dispersal of a sulfur dioxide-rich aerosol to increased soil acidity and increased uptake of metals from the forest soil.1". The model assumes Au will follow Cu up the nutrient pathway 2 13 . Once within the tree, Au forms complex ligands with organic molecules and remains relatively immobile'6-20 , allowing correlation with external events on the scale of a single ring/year. See references 21-23 for discussion of general limitations of trace element analysis in dendrochemistry. Ion uptake, specifically the determination of trace amounts of gold, can be performed for dendrochronologically-dated wood samples and the concentration of gold compared to dated events, e.g. volcanic activities.

The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology at Cornell University archives over 40,000 individually-dated tree samples with 4.5 million rings from one hundred and nine forests in the eastern Mediterranean and former Soviet Union. These samples span most of the period from 7000 BC to the present 24 25 (Fig. 2). All dendrochronogically dated samples at the Wiener Laboratory are available for this study. Staff and students of the Wiener Laboratory have already prepared approximately three thousand samples of wood, each from a single year, for this study.

45

NAA is the assay of choice for Au in organic material. Au has a large neutron cross-section and NAA can detect the element in the parts-per-billion (ppb) range2 6 . A dedicated NAA system was built at Cornell's Ward Center for Nuclear Sciences for this study with NSF and Cornell funds. Samples were activated at the core of Cornell's 500 kW TRIGA Mark II research reactor and NAA measurements performed using a spectroscopy facility with automatic sample changer system. After Cornell's decision to close the Ward Center for Nuclear Sciences, the prepared samples, gamma spectroscopy system, and sample changer were transferred to Penn State, Radiation Science and Engineering Center. Measurements will continue at Penn State using the I MW Breazeale Nuclear Reactor.

Fig. 1. This model anticipates increased uptake of copper, gold, silver and heavy metals with increasing soil acidity. Glutathione (GSH) increases due to oxidative stress and higher levels of sulfur and selenium following a volcanic eruption. Neutron activation (NAA), X-ray fluorescence (XRF), and plasma analysis (ICP) may record yearly change in the metal content of tree rings.

46

After initial measurements, samples containing elevated levels of gold can be re-analyzed for short and long half-life elements, e.g. silver, copper, etc., to investigate other elemental signatures of environmental change. NAA is the ideal technique for this study. It is nondestructive and sensitive. Other techniques, like ICP-MS, are destructive and sample preparation may introduce impurities and change the concentration of trace elements.

~.

i ....... ....... .. .. .. . . .. .. ... .... ... .........

He~ ~ ~ m

• um_

I~~~ U Fir h U oe EU_' - - a r l Ccwiterr Cbontl.d _

• d ,U *

• I.

-TV fi4XI -DPB -;~C% -313O soJ *Dc~t 1 'A7 i32U Pffeds 0166"Ic C1abc4Utk Eady Mddl Bra Af Cals Odlva b A f ft MAepan Ttee-Rnp CErg4%*9 as Spoing 2000 ;_ mauuriq 1t Gre Fig. 2. Summary of wood available for this study at the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology at Cornell University.

This research is a multidisciplinary study involving group of scientists, graduate and undergraduate students from the Radiation Science and Engineering Center (RSEC) at Penn State and M. and C. Wiener Laboratory for Aegean and Near Eastern Dendrochronolgy at Cornell. To the best ofour knowledge, this is the first such collaborative study across deep time. As a result ofthe research proposed here, a close collaboration between the faculty, staff, and students at RSEC and Cornell's M. and C. Wiener Laboratory will be established. It is expected that gold concentrations will help define years of high atmospheric SO2 and accompanying periods of increased soil pH. Thereby, a correlation can be made with ion uptake of dendrochronologically-dated woods and environmental change. The results ofthe proposed study will provide environmental modelers with a six thousand year historic record and give archaeologists exact dates for significant volcanic events in prehistory. The results should be applicable to northern hemisphere forests and, possibly, worldwide.

47

AdedicatedNAA laboratory with an automated sample-changer system, a High Purity Germanium detector, data acquisition and processing electronics for the NAA spectroscopy was built using partial funds from NSF (through Cornell University) and RSEC. The preliminary results support the hypothesis that determination oftrace elements e.g. gold in dendrochronologically dated tree rings can help correlate the date of environmental changes.

Experimental Facilities and Procedures Dendrochronologically-dated samples for this study are from the Malcolm and Carolyn Wiener Laboratory forAegean and Near Eastern Dendrochronology at Cornell University, where an archive of 40,000 measured and cross-dated samples with approximately 4.5 million rings is available.

Samples have already been cut from each ring using the same tools in a clean environment, placed in polyethylene bags, and heat-sealed. Sealed samples were put together in a large polyethylene vial and irradiated at 300 kW reactor power for four hours in a TRIGA-Mark II reactor at the edge of a graphite reflector. Thermal and epithermal neutron flux at this location was 1.02 x 1012 n/cm2 sec and 1.17 x 1010 n/cm2 sec respectively. Each run was accompanied by a gold wire for flux measurement.

After irradiation, samples were taken from the heat-sealed bags, weighed, placed in small vials, and labeled. Figure 3 shows a wood sample, cut samples from rings, samples after irradiation, and archived samples. To decrease the contribution of sodium (Na) to the spectrum, counting started approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after irradiation. Each sample was counted for one hour.

....E_ -

Fig. 3. a) typical wood sample, b) samples cut from single ring and heat-sealed in bags, c) samples after irradiation and weighing, but before counting, d) archived samples.

48

An automated sample handling system was built to handle the volume of samples in a reliable, consistent manner and reduce errors. The system consists ofa rotary sample table, pneumatic horizontal-transfer arm, pneumatic motion slide, gripper actuator, sample nest, and logic control system. Figure 4 shows the system, detector, and shielding. The outside row of a rotary table holds 90 samples prior to analysis. The system performs the following movements: 1) an irradiated sample is picked from the sample table and transferred to a sample nest above the detector; 2) the arm retracts to home; 3) upon receipt of a signal from the spectrometer indicating programmed counting time is over, the arm moves to the detector, picks up the counted sample and places it in the inside row of the rotary table. All motions are controlled via a programmable logic controller. Counting of each sample can be individually programmed and integrated with the spectroscopy system computer. The automatic sample handling system provides sequential presentation of samples to the detector for analysis with. Cycle time is less than 10 seconds.

A state-of-the-art gamma spectroscopy system is used for data acquisition and analysis. The system includes a 40% efficient HpGe detector in a well-shielded cave, a digital spectrum analyzer, and a computer with Genie2000 software. For each run a flux wire was used for flux measurements. We plan to continue irradiating up to 90 samples for 4 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> each at the 1 MW Breazeale Nuclear Reactor and count each sample for 30 minutes after a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> wait. Samples are archived after counting is complete. Samples showing elevated Au may be re-analyzed to determine other trace elements.

I Fig. 4. Automated sample handling system and HpGe detector with shielding 49

Preliminary Results and Discussions Initially, ca. two thousand rings from trees in Turkey and Greece were analyzed for Au27 . Data presented here are from a single tree that grew in Greece from 1411 until 1988 AD. A typical spectrum for one ring is given in Figure 5 shows the Au-198 peak at 411.8 keV for 1846 AD.

Although we allowed 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> cooling time for each sample, the Na-24 peak (2752 keV) dominates the spectra. Eight isotopes were consistently identified: Na-24, K-42, Cu-64, Pa-233, Zn-96m, Mn-56, Br-82 and Au- 198. Basic properties for identified isotopes are given in Table 1.

1368.60 keVa 411.80kcVtAu 84G.'VM, \ 1460. keVK 2754.00 keV1a 511 ke'1548 f Example Tree-Ring Gamma Sp. -

C So 1000 PholonE..r 1500 2000 2500 3000 Fig. 5. NAA spectrum of a sample from 1846 AD showing subset of major and trace elements. Gold, Au- 198, is present as a trace compared with Na-24.

Elemental concentration of tree ring samples for the years 1411-1429 AD is given in Table 2. In this table A/m denotes activity per mass in Becquerel (Bq) per gram and C is concentration in ppm. In some years we observed an elevated level ofAu, while in other years the Au was below our minimum detection limit. For example, for the years 1411-1429 we were unable to detect Au in 1419, 1423, 1426, and 1429 AD. The maximum concentration of Au was found in wood of the year 1413 AD (0.879 ppm). Measured amounts of other identified isotopes also varied from year to year.

Percent error for concentration varies from 15% to 65% depending on the amount of Au in the sample. Percent error is based on statistical counting, weighing error, and precision of standard efficiency measurement. Our minimum detection limit forAu-198 varied from 1.4 x 10-3 to 7.6 x 10-3ppm based on the spectral background platform.

Results presented here are based on samples from a single tree. A more comprehensive analysis will be available when we complete analysis of several thousand samples from multiple localities. The following discussion is based on our preliminary results. Figure 6 shows data for Au concentration and major known volcanic activities. The data for Au concentration within each tree ring was normalized by setting .03123 ppm equal to one and adjusting other values accordingly. The value

.03123 ppm is the second highest value found between the years 1411 and 1699 AD. The highest 50

value occurred in 1413, whenAu concentration was anomalously high (.8788 ppm). The dashed line represents average Au concentration for a year and the following two years. The choice of a three-year average was based on the time that volcanic debris usually remains in the upper atmosphere.

Data points represent measured Au concentration. The average Au concentration between 1411 and 1699 AD is .00728 ppm. This average does not include data for years in which no Au was found.

For those years there was not enough Au in the sample to produce a recognizable gamma peak at 411.8 keV.

Table 1. Identified Isotopes for typical runs for tree ring samples Isotope Name Half Life Gamma Energy Production Method (with Precursor's (keV) thermal neutrons) Isotope Abundance Potassium-40 1.28 x 10 yr 1460.83 Natural Product 1.17 (40K)

Bromine-82 35.3 h 554.35 8 Br+1n-.82 Br + y 49.3 82

( Br) 619. 11 3B~n+5B~

698.37 776.52 827.83 1044.08 1317.47 1474.88 Sodiun-24 14.96 h 1368.60 23 Na+n. 24 Na + y 100 (2 4Na) 2754.00 1 0 1 1 Zinc-69m 13.76 h 438.63 6 8 Zn+Ilno 69mZn +y 18.80 69

( Zn) __ _ _ __ 30____

_ _30__ _ __ _ _ _

Copper64 12.70h 511.00 63Cu+ n64Cu + 69.17 (64Cu) 291345.77 o 29 Potassium-42 12.36 h 1524.58 4 K+'no 42 K+y 6.7 562 'Mn+On-+Mn 9 00 Manganese-56 2.58 h 846.76 55Mn+ no 56 + y loo (56Mn) 1810.72 25 0 25 2113.05 Gold-198 2.70 d 411.80 19 7 9 8 Au+

98Au+'n.. 100 8

('" Au) _________ 675.89 790~l-79Au y Protactinium-233 27.0 d 75.34 2 32Th+ n1 233 Pa+r 100

~ pa) 3 86.6590. o->9 a y 300.18 312.01 340.59 398.66 415.93 Volcanoes shown in Figure 6 include all known between 1411 and 1699 AD with a Volcanic Explosivity Index (VEI) of 5 or greater 28 . Such volcanoes tend to inject significant amounts of debris into the stratosphere. VEI, however, is not an absolute quantifier. Properties of volcanoes with similar VEI may very greatly. One characteristic, hard to identify for historic volcanoes, is the amount of SO2 released. A good data set for identifying years with increased atmospheric acidity (and increased likelihood of acid rain) has been derived from ice cores with the caveat that are errors in counting ice layers.

51

Table 2. Elemental concentration of tree ring samples for the years 1411-1429 AD from Greece.

In this table A/m denotes activity per mass in Becquerel (Bq) per gram and C is concentration in ppm.

Element Concentration Report C-GR-PPG-4 Years 1411-1429 Au 198 Br 82 Na 24 K 42 Cu 64 A/m C A/m C A/m C A/m C A/m C 1411 5726 1.403E-02 3703 2.766E-01 1844000 I.165E+02 176800 1.001 E+02 240000 4.248E+01 1412 7603 1.863E-02 3903 2.916E-01 2083000 1.316E+02 209300 1.185E+02 250100 4.427E+01 1413 358700 8.788E-01 3004000 1.899E+02 275800 1.561E+02 372300 6.590E+01 1414 1436 3.518E-03 3245 2.424E-01 1120000 7.078E+01 111400 6.305E+01 138800 2.457E+01 1415 3314 8.119E-03 2086 1.558E-01 1005000 6.352E+01 105100 5.949E+01 121200 2.145E+01 141 4075 9.984E-03 4263 3.184E-01 1847000 1.167E+02 168900 9.560E+01 204400 3.618E+01 1417 5211 1.277E-02 4642 3.468E-01 1534000 9.695E+01 168800 9.554E+01 17980 3.182E+01 1418 1390 3.406E-03 3175 2.372E-01 957700 6.053E+01 91980 5.206E+01 131400 2.326E+01 1419 3071000 1.941 E+02 232800 1.318E+02 354200 6.269E+01 142C 3758 9.207E-03 4338 3.240E-01 2276000 1.438E+02 199600 1.130E+02 249600 4.418E+01 1421 2500 6.125E-03 2869 2.143E-01 1202000 7.597E+01 109700 6.209E+01 151500 2.682E+01 1422 2608 6.390E-03 3197 2.388E-01 1231000 7.780E+01 110400 6.249E+01 161000 2.850E+01 1423 4826 3.605E-01 2021000 1.277E+02 179300 1.01 5E+02 235100 4.161 E+01 1424 2518 6.169E-03 936.8 6.998E-02 1167000 7.375E+01 100200 5.671 E+01 144700 2.561 E+01 1425 1506 3.690E-03 2061 1.540E-01 2020000 1.277E+02 177300 1.004E+02 23480 4.156E+01 142( 2735 2.043E-01 1234000 7.799E+01 113200 6.407E+01 166000 2.938E+01 1427 1633 4.001 E-03 3555 2.656E-01 1169000 7.388E+01 106400 6.022E+01 177000 3.133E+01 1428 2532 6.203E-03 2633 1.967E-01 1363000 8.614E+01 126600 7.166E+01 191900 3.397E+01 142S 3354 2.505E-01 1252000 7.913E+01 134900 7.635E+01 185200 3.278E+01 However, only one of the pre-modern volcanoes (Kuwae, 1452 AD) has been dated using ice core data. Yearly layer counts in ice cores can not yet be replicated in the same manner as tree rings. Ice-core dating of volcanoes may place the date of the eruption within the nearest fifty years. Some volcanoes are recorded only through ambiguous or conflicting reports. We think our well-replicated tree-ring sequences, accurate to the year, offer a greater potential for the study of palaeoclimate.

Figure 7 shows Au concentration and tree-ring width. Both are normalized and averaged according to the process described above. Major eruptions have been included. For the years presented there is no easily discernible correlation between Au concentration and ring width. This suggests that factors affecting Au uptake such as acid rain, are not directly correlated with factors affecting tree growth, such as yearly average temperature.

52

Fig. 6. Gold concentration for a tree that grew in Greece from 1411 to 1699 AD. Major known volcanic activities in this period are listed.

0.8 t 0.6 0.4 0.2

-0.2

-0.4

-0.64 , I I 1400 1420 1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640 1660 1680 1700 Fig. 7. Gold concentration and tree ring width for a tree that grew in Greece from 141 1 to 1699 AD. Major known volcanic activities in this period are marked.

53 CyL2~

Summary Gold concentrations may help define years of high atmospheric SO 2 and increased soil pH. It may be possible to demonstrate a connection between Au concentration in dendrochronologically-dated wood and environmental change. Findings of this study will provide environmental modelers with a six thousand year record of change and give archaeologists exact dates for significant volcanic events in prehistory. Results of this study will also be applicable to northern hemisphere forests and, possibly, worldwide. We present here preliminary results of our study using wood from a single tree that grew in Greece from 1411 to 1988 AD. After initial scans are completed, samples with elevated Au will be re-analyzed to determine other elements correlated with environmental change. Our immediate goal is to quantify yearly Au from the eighteenth and nineteenth centuries.

Recent volcanic eruptions such as Tambora in 1815 and Krakatoa in 1883 are better documented and more accurately dated and are matched by Au spikes. This provides a stronger test of the possible correlation of Au with volcanic activity. Au concentrations in the tree-rings are being compared to the ice core data to identify eruptions that increased soil acidity.

This study is multidisciplinary in nature, involving contributions of many individuals. These include the staff and students of the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology and the Ward Center for Nuclear Sciences at Cornell University, the Radiation Science and Engineering Center at Penn State University, Drs. Leonard Weinstein and Jonathan Comstock of the Boyce Thompson Institute for Plant Research at Cornell University, Dr. Leon Kochian of the Plant Biology Department, Cornell University and Dr. Arthur DeGaetano at the Department of Earth and Atmospheric Sciences, Cornell University. The National Science Foundation, the Ward Center for Nuclear Sciences at Cornell University, and the Malcolm H. Wiener Foundation supported the initial phase of this study.

Bibliography

1. Anon. "Absorption of gold by plants, " United States Geological Society Bulletin B1314 (1970).

2. Stewart, K.C. and D.M. McKown. "Sagebrush as a sampling medium for gold exploration in the Great Basin: Evaluation from a greenhouse study," Journal of Geochemical Exploration, 54(1): 19-26 (1995).

3. Anderson, C.W.N., R.R. Brooks, R.B. Stewart, and R. Simcock. "Harvesting a crop of gold in plants," Nature 395: 553-4 (1998).

4. Anderson, C.W.N., R.R. Brooks, A. Chairucci, C.J. Lacoste, M. Leblanc, BH. Robinson, R. Simcock, and R.B. Stewart. "Phytomining for nickel, thallium, and gold," Journal of Geochemical Exploration 67(1-3): 407-415 (1999).

54

5. Kim, J.-K. "Analysis ofheavy metals in tree rings ofPinusdensifloragrown in industrial and non-industrial areas," pages 105-111 in Proceedings ofthe East Asia Workshop on Tree-ring Analysis W.-K. Parked., Choengju, Korea, 206pp. (1997).

6. Angerhn-Bettinazzi, C., L. Thoni, and J. Hertz. "An attempt to evaluate some factors affecting the heavy metal accumulation in a forest stand," Intern. J. Environ. Anal. Chem.

35: 69-79 (1989).

7. Baes, C.F., III and S.B. McLaughlin. "Trace elements in tree rings: evidence of recent and historical air pollution," Science 224: 494-497 (1984).

8. Guyette, R.P., B.E Cutter, and GS. Henderson. "Long-term correlations between mining activity and levels of lead and cadmium in tree-rings of eastern red-cedar," Journal of Environmental Quality 20(1): 146-150 (1991).

9. Pernestal, K.B. Jonsson, J.-E. Hallgren, and K.-K. Li. "Elemental content of tree samples from an acidic and a limed environment investigated by means of PIXE," Lundqua Report 34: 259-263 (1992).

10. Pohlman, A.A. and J.G McColl. "Kinetics of metal dissolution from forest soils by soluble organic acids," Journal of Environmental Quality 15(1): 86-92 (1986).

11. Rea, D.K. "The paleoclimatic record provided by eolian deposition in the deep sea: the geologic history of wind," Reviews of Geophysics 32(2): 159-195 (1994).

12. Baker, A., R. Brooks, and R. Reeves. "Growing for gold, and copper, and zinc," New Scientist 117: 344-48 (1988).

13. Hantemirov, R.M. "Possibility to use chemical elements in tree rings of Scots pine for the air pollution reconstruction," Lundqua Report 34: 142-145 (1992).

14. Jarvis, S.C. "Copper concentrations in plants and their relationship to soil properties,"

pages 265-285 in Copper in Soils and Plants. J.F. Longeragen, A.D. Robson, AND R.D.

Graham, eds., Academic Press, New York, xv+380 (1981).

15. Streit, B. and W. Stumm. "Chemical properties of metals and the process of bioaccumulation in terrestrial plants," pages 31-62 in Plants as Biomonitors B.MARKERT (ed.), VCH Publishers, New York, xxxiii-644.

16. Chiment, J.J., R. Alscher, and P.R. Hughes. "Glutathione as an indicator of S02-induced stress in soybean," Environmental and Experimental Botany 26(2): 147-152 (1986).

17. Grill, D., H. Esterbauer, M. Scharner, and CH. Fetlgitsch. "Effect of sulfur-dioxide on protein-SH in needles of Picea abies," Eur. J. For. Pathol. 10: 263-267 (1980).

55

18. Grill, D., H. Esterbauer, and K. Hellig "Further studies on the effect of S02-pollution on the sulfhydryl-system ofplants," Phytopathol. Z. 104: 264-271 (1982).

19. Robson, A.D. "Conclusion: copper in soils and plants-and overview," pages 351-354 in Copper in Soils and Plants, Academic Press, New York, xv+380 (1981).

20. Sheppard, J.C. and W.H. Funk "Trees as environmental sensors monitoring long-term heavy metal contamination of Spokane River, Idaho," Environmental Science and Technology 9:

638-642 (1993).

21. Cutter, B.E. and R.P. Guyette. "Anatomical, chemical, and ecological factors affecting tree species choice in dendrochemistry studies," Journal of Environmental Quality 22(3): 611-619 (1993).

22. Hagemeyer, J. "Monitoring trace metal pollution with tree rings: a critical reassessment,"

pages 541-563 in Plants as Biomonitors, B. Markert (ed.) VCH Publishers, New York, xxxiii+644 (1993).

23. Smith, K.T. and W.C. Shortle. "Tree biology and dendrochemistry," pages 629-635 in Tree Rings. Environment and Humanity J.S. Dean, D.M. MekoAND T.W. Swetnam, eds.,

Radiocarbon Tucson (1996).

24. Kuniholm, P.I. "Archaeological evidence and non-evidence for climatic change," in S.K.

Runcom AND J.-C. Pecker, eds., The Earth's Climate and Variability of the Sun Over Recent Millennia. Phil. Trans. R. Soc. Lond. A, 645-655.

25. Kuniholm, P.I. "The Prehistoric Aegean: Dendrochronological Progress as of 1995,"

Absolute Chronology: Archaeological Europe 2500-500 B.C. (= Proceedings of the Verona Chronology Conference 1995) Acta Arcaeologica 67 Acta Archaeologica Supplementa Vol. 1: 327-335 (1996).

26. Guyette, R.P., B.E. Cutter, and G.S. Henderson. "Inorganic concentrations in the wood of eastern red cedar grown on different sites," Wood and Fiber Science 24(2): 133-140 (1992).

27. Jnlii, K., P.I. Kuniholm, J.J. Chiment, D.K. Hauck. "NeutronActivationAnalysis of Absolutely-Dated Tree Rings," Accepted for publication in J. of Radioanal Nucl Chem, (2003).

28. Simkin, T., and L. Siebert, Volcanoes of the World, 2nd Edition, GeoScience Press, Tucson (1994).

56

Angul ar Correlations Laboratory

VII. ANGULAR CORRELATIONS LABORATORY The Angular Correlations Laboratory has been identified many drag-reducing polymers, in operation for approximately 14 years. The investigators have not been able to observe laboratory, which is located in room 116 and directly the polymer-solvent interactions room 4 of the RSEC, is under the direction of causing drag reduction. For this purpose, Professor Gary L. Catchen. The laboratory Professor Catchen is using PAC spectroscopy.

contains three spectrometers for making Perturbed Angular Correlation (PAC) measurements. One apparatus, which has been in operation for 16 years, measures four coincidences concurrently using cesium fluoride detectors. A second spectrometer was acquired 12 years ago, and it measures four coincidences concurrently using barium fluoride detectors. A IW third spectrometer was set up eight years ago to accommodate the increased demand for measurement capability. The detectors and electronics provide a nominal time resolution of I nsec FWHM, which places the measurements at the state-of-the-art in the field of perturbed angular correlation spectroscopy.

Penn State has a unique research program that uses PAC Spectroscopy to characterize technologically important electrical and optical materials. This program represents the synthesis of ideas from two traditionally very different branches of chemistry; materials chemistry and Figure 1. Prof. Catchen inserts a sample into a high-nuclear chemistry. Although the scientific temperature sample furnace, which is mounted in the center of the four-detector array of the perturbed-questions are germane to the field of materials angular-correlation spectrometer chemistry, the PAC technique and its associated theoretical basis have been part of the fields of The PAC technique is based on substituting a nuclear chemistry and radiochemistry for radioactive probe atom such as "'In or 8'Hf several decades. The National Science into a specific site in a chemical system.

Foundation and the Office of Naval Research Because these atoms have special nuclear have sponsored this program in the past. properties, the nuclear (electric-quadrupole and magnetic-dipole) moments of these atoms can Currently Professor Catchen is executing a interact with the electric field gradients (efg's) research program funded by the Petroleum and hyperfine magnetic fields produced by the Research Fund of the American Chemical extranuclear environment.

Society. It is titled: "Drag Reduction in Turbulent Flows: Direct Observation of Very Static nuclear electric-quadrupole interactions Rapid Fluctuations in Polymer-Solvent can provide a measure of the strength and Interactions." Low concentrations of linear symmetry of the crystal field in the vicinity of polymers can greatly reduce drag in various the probe nucleus. In the case of static types of fluid transport. Although scientists have interactions, the vibrational motion ofthe atoms 57

in the lattice is very rapid relative to the PAC timescale, i.e., 0.1-500 nsec. As a result, the measured efg appears to arise from the time-averaged positions of the atoms, and the sharpness of the spectral lines reflects this "motional narrowing" effect. In contrast to static interactions, time-varying interactions arise when the efg fluctuates during the intermediate-state lifetime. In solids, these interactions can provide information about defect and ionic transport. In liquids these interactions can provide information about, for example, the conformations of macromolecules such as polymers. The effect of the efg fluctuating in either strength or direction, which can be caused, for example, by ions "hopping" in and out of lattice sites or by molecules tumbling in a solution, is to destroy the orientation of the intermediate state.

Experimentally, this loss of orientation appears as the attenuation or "smearing-out" of the angular correlation. And, often a correspondence can be made between the rate of attenuation and frequency of the motion that produced the attenuation.

Magnetic hyperfine interactions, which can be measured in ferromagnetic and antiferromagnetic bulk and thin-film materials, are used to study the mechanisms that cause the transition between the magnetically-ordered phase and the disordered phase.

Current laboratory research is detailed in Section XI of this report.

58

l - mi - -

4 p tos - -0000 i .

I

.4 1*' t. i t;

I:

f I,

I i; I f r la1 i

'I I I

• 1 4

f IlEAWE KOMDIN I e.

ia i l

I -;~.

ft II t A

.! [.",

1 1 1F . :4m I iF i

atl hjb

• -P C: .;:1 1, AIe

IX. LOW-PRESSURE INTEGRAL TEST FACILITY L INTRODUCTION The Penn State Low-Pressure Integral Test Facility (LPITF) is a one-half height scaled representation of the General Electric's Simplified Boiling Water Reactor (SBWR). The unique characteristic of the facility is that it was designed, built, and engineered by Penn State Nuclear Engineering undergraduate students. The facility was started in 1995 with funding from the Dean of Engineering. Subsequent funding was obtained from different companies, such as Westinghouse, Rosemount-Fisher and others as well as matching funds from the Department of Energy. Penn State students participated in the scaling analysis used for the design, the hardware design, and fabrication of the facility components, analysis of the facility response, testing and analysis associated with the data. The facility operates near atmospheric pressures to take advantage of displaying boiling phenomenon at relatively lower temperatures.

The facility underwent a great deal of modification over the last year. The previous facility design had some problems with the two-phase natural (re)circulation. A new design is introduced to overcome some of the problems in flow stability (Figure 1). The new design also incorporates a motor actuated valve to improve the controllability of the loop (Figure 3).

Figure I - Detail of the modifications to the downcomer line and crossover leg.

59

11. DESCRIPTION OF FACILITY The reactor core is simulated using 12, one-half height electric heater rods, as can be seen in Figure 2.

Four rods have four embedded surface thermocouples each, which determine the temperature profile along the bundle. Additional heater rods have a thermocouple near the exit of the heated length. The heater rods are connected to silicon controlled rectifiers (SCR), which provide the electrical power to the rod bundle. The glass channel diameter is 3-inches, which was obtained by scaling the facility to the SBWR.

The core and the downcomer regions of the test loop are partially made of borosilicate glass so that the flow can be seen. This configuration allows students to visually study the boiling process and two-phase flow behavior over a range of thermal-hydraulic conditions. Figure 3 shows the front-view of the test loop. To the right is the borosilicate glass core. There are several penetrations on the core section for instrumentation including pressure transducers, void probes, and thermocouples.

I I

I 4 He Vy~~03,0000 I

I I

I 480 +030 I

I I

I 00,4830 I

I I

I Figure 2 - Core rod layout.

60

Figure3 - Front view of the test loop core section. The core is located on the basement of the Cobalt-60 irradiation facility.

11. MODIFICATIONS AT THE FACILITY The previous design had stability problems for two-phase (re)circulation experiments. The facility was designed to simulate the basic behavior of SBWR, however drastic differences in operating conditions resulted in major problems in the operation of the facility. First of all, SBWR operates at pretty high pressures relative to the LPITF. Operation at near atmospheric pressures makes the facility vulnerable to gravity, acceleration, and friction pressure drop; because as the water rises in the chimney section, it loses its head resulting in a considerable pressure loss compared to the operating pressure level. This has a significant impact on calculations regarding to two-phase flow. This cannot be resolved by any means other than changing the operating pressure of the facility.

The other problem was flow reversal to the main condenser: Since the two-phase flow experiments did not involve the main condenser in order to reduce water inventory, the portions of the facility above the steam separator were under vacuum. Water at a relatively higher pressure forced water/steam mixture through the condenser return line. Water forced to the condenser got cooled down and turned back to the circulation below saturation temperature resulting in change in temperature distribution along the loop.

61

The new design employs a three-leg downcomer section, which separates steam separator return line, condenser return line and downcomer line from each other. This way water/steam mixture has a less probability to flow to the condenser and affect the temperature distribution of the system at quasi-equilibrium. This modification is expected to reduce geysering and improve two-phase flow stability.

Figure4. Modifieddowncomersection:This design eliminatesflow reversaltothe steam separatorand/ormain condenser.

One other modification involved the flow control: Flow rate is related to the temperature distribution along the loop and the temperature gradient between the hot and cold legs. There was no direct control over the flow, but through the condenser flow rate, which had a minuscule effect. With the addition of flow control valve (Figure 5), one can restrict the maximum flow rate through the core and reduce the number of geysering cycles in the unstable two-phase flow regime. The electric motor actuated valve is equipped with a bypass line to guarantee a minimal flow rate in the case of a valve failure.

62

Figure5. Electric motor actuatedvalve and bypass valve.

IV INSTRUMENTATION The state of the loop is observed through a number of instrumentation:

i. Flowmeter: A very sensitive magnetic flowmeter; located on the pipe between the downcomer and heater rod bundle lower plenum.

ii. Pressure transducers: Absolute and differential pressure measurements to estimate the average void fractions in two-phase flow.

iii. Void probes: The miniature void probes penetrate into the piping and bundle, and determine the local void concentration at different locations.

iv. Thermocouples: There are two different J-type thermocouples: surface thermocouples, which are inside the heater rods and measure the heater rod surface temperature; and fluid thermocouples, which measure the local fluid temperature. The computer hardware allows up to 64 simultaneous thermocouple connections.

v. Power transducers: The power applied through the SCR's is read back to verify electrical heat input.

63

A computer reads the measurements and displays them through an interface application designed in LabVIEW (Figure 6). This application also interfaces to the control the power signal for SCR's, which in turn controls the electricity input to the rod bundle.

50gt^SED TwME

\_J 111l l Il I11 *

~~~~~1

._. t . ~~~.

4)__

a... ,

.00 .. 0 20

£5 0.O 0.00 10 ~~40~

to 1

I.00I 5

ii la 000 l~~~~~~~i~6 oo~~~~~~~~a Figure 6 - Screenshotfrom the LabVIEW main control interface.

V TYPES OF EXPERIMENTS The main objective of the test loop is for students to understand the principles of single-phase and two-phase natural circulation flow and heat transfer behavior. The students determine energy balances over the system, and observe the two-phase natural circulation.

64 A, b :

IVA. Single-Phase NaturalCirculationExperiments During 2000-2001, single-phase experiments were performed in the spring. The students were requested to check the physical integrity of the facility, get acquainted with the instrumentation, and verify that the electrical energy transferred to the core matched the energy transfer in the primary side of the main condenser as well as the energy transfer in the secondary side of the main condenser. The students also developed calculational models to predict the natural circulation flow in the test loop. Calculations were also performed with the TRAC-PF-I code.

120 l 110 1 1001! 1 T 0-i- 90 Bundle Outlet E 80 -

70 l / ~~~~~~~Bundle Inlet 60 50 T_

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Time (sec)

Figure 7 - History of the core mean temperatures duringa single-phaseflow.

Figure 7 and Figure 8 show the fluid temperature behavior during the single phase natural circulation experiment along the core and in the main condenser. The flow becomes established as the temperature difference develops between the hot and the cold legs, as can be seen in Figure 9. The heater rod axial temperature distribution is shown in Figure tO for this experiment.

65 CoI&

Time (sec) 1000 2000 3000 4000 5000 6000 7000 8000 9000 Time (sec)

Figure 8- Temperature history in the main condenser.

66

3-2.5 2

_ 1.5 I

.2 1

> 0.5 0

-0.5 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Time (sec)

Figure 9- Single-phase naturalcirculationflow rate.

110 100 90 I

8 I

10000 Figure 10 D profile along the core of the fluid temperaturefor this particularexperiment.

All 67 C

IVB. Two-Phase Natural Circulation Experiments Two-phase natural circulation experiments have also been performed in the facility and are very useful for the students to observe the boiling process and flow regime behavior along the vertical channel, which contains the rod bundle. Subcooled nucleate boiling can be observed, with very small bubbles being formed at the heater rod surfaces. As the coolant is heated to saturation, bulk boiling occurs and several different flow regimes such as bubbly, slug, and churn-turbulent flow can be observed.

110 II I I Bundle Inlet I I I Bundle Exit .j 100 -I - - +-1_ -_1 90 ________ I_'_ I> r-80I I I 1. ;1, 17 1 1 t8 0 - - - - - - - - -- +- t-8$1--t--t--- - -0 AX- 70_ _

IiL. _ I211v- -- -

21 - - F- - X - - - - -~

E I 60f I I I l li III a, 50 - 40 g--I--I--I--~

-- I-- -- l- __

30__Ia)[s__ I -4T - - - - --

40 - - - - - - - - - - - - - - - - - - -

30 I 2-20 IIII ---+/-

I 4--

I - -I - - --

10 I I 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time (hr)

Figure 11 - Corefluid temperaturehistory.

The two-phase natural circulation experiments are initiated as single-phase natural circulation test to heat the fluid to the saturation temperature. Once the fluid approaches saturation temperature, the facility is partially drained, which reduces the system pressure. As a result of the reduced system pressure, the remaining water in the facility starts to boil with lower heat input. Figure 11 shows the temperature of the bundle inlet and exit as the facility transitions into a two-phase mode after approximately three hours.

06

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time (hr)

Figure 12 - Flow rate during the two-phase naturalcirculation experiment.

Figure 12 shows the stable single-phase natural circulation flow, which then transitions to a very oscillatory flow once the system is in two-phase natural circulation. The two-phase flow oscillation experiments are part of a Department of Energy NEER program, which studies BWR flow/power stability.

I it~~~~~~~~~~ -

Figure 13 - The riser, chimney sections of the core; crossover leg, and steam separator.

69

VI. CONCLUSIONS The Penn State Low Pressure Integral Test Facility has proved to be a very effective learning tool for nuclear and mechanical engineering students. This facility allows the students to gain "hands-on" learning experiences in design, fabrication, and thermal-hydraulic testing and analysis. It provides the students with an opportunity to observe the complex boiling and two-phase flow processes that occur in commercial light water reactors and other boiling systems.

Figure 14 - A closer look to the crossover leg and the steam separator.

70

n~~~IneF

.X i_ r-

X. ENVIRONMENTAL HEALTH AND SAFETY Environmental Health and Safety (EHS) is an handled in a safe and controlled manner. The active participant in ensuring the overall safety surveys were conducted to detect possible of the Radiation Science and Engineering Center transferable contamination from radioactive (RSEC) operations. The RSEC and EHS are materials work or to survey radiation sources committed to the health and safety of the such as activation products, sealed sources, environment, public, students and employees. equipment, and reactor operations. The EHS is responsible for the overall administration radioactive contamination surveys are of the radiation safety program for Penn State. performed in laboratories where radioactive The University is licensed by the U.S. Nuclear materials are used and in the balance of the Regulatory Commission (NRC) to receive, RSEC's public areas to ensure that no acquire, possess, and transfer byproduct radioactive material has been transferred to material (radioactive material produced by a these areas. Both the contamination surveys and nuclear reactor), source material (naturally the radiation surveys are redundant to the occurring radioactive material, uranium surveys performed routinely by the RSEC staff.

compounds), and special nuclear material The redundancy of the contamination and (radioactive material that has the potential to radiation surveys is fundamental to the university's undergo nuclear fission) and to operate the ALARAprogram.

Breazeale Nuclear Reactor at the Radiation Science and Engineering Center. The College of Engineering has administration responsibility for the reactor operations license (R-2 license).

The ALARA radiation protection philosophy, keeping the radiation exposure as low as reasonably achievable, is the basis for the RSEC and EHS radiation protection and safety programs. Both groups collaborate to maintain the highest level of health and safety programs necessary for the administration of nuclear programs and compliance with federal and state regulations.

Services provided to the RSEC fall into the following categories: "ALARA" program, customer service, licensing and regulatory requirements, and training.

ALARA Program This year EHS performed over 130 radiation surveys at the RSEC. Survey results showed that there were no radioactive contamination surveys or radiation surveys above established limits and radioactive material was being 71

EHS staff regularly attend scheduled RSEC The exposure was to the hands of reactor personal operation meetings. The meetings provide a forum analyzing samples in the neutron beam lab. The for participants to review the current reactor corrective action implemented involved designing operations and experiments. This active a new rack to hold the samples. The new rack participation has established an open line of replaced much of the aluminum with wood, which communication between the RSEC and EHS. would not become activated by the neutron beam.

Input by the radiation protection staff has The follow up investigation, which was conducted contributed to the facility's safety and ALARA this year, determined that the corrective action did program. correct the problem and hand doses returned to normal. Administration of the dosimeter program includes issuing dosimeters, processing dosimeters Customer Service and maintaining all dosimetery records. The RSEC's director is provided with quarterly EHS is responsible for the shipping and transfer dosimeter reports for his review. Additionally, of radioactive materials (RAM) to customers EHS provides on request, by signed permission other than the RSEC. The U.S. Nuclear only, dosimetry reports for reactor personnel and Regulatory Commission and U.S. Department students so they can trace their exposure history.

of Transportation mandate complex EHS has administered a thermal neutron dosimeter requirements for the packaging, shipping and program to check exposures more accurately for transfer of radioactive materials. EHS facilitated those working around the neutron radiography twelve shipments of RAM for RSEC customers. laboratory. One neutron dosimeter is a permanent Customer support included packaging and shipping Ar-41 and Na-24 for Tru-Tec Inc., Ar-41 for Synetix Inc. and Na-24 for NWT Inc. The shipping and transfer of radioactive materials includes the disposal of reactor radioactive waste materials.

In June RSEC and EHS personnel started to perform the necessary inspections and surveys of the Pathfinder fuel in order to prepare it for shipment.

Licensing and Regulatory Requirements Dosimetery requirements are administered by EHS and dosimetry is issued to RSEC personnel to measure staff, student, and worker radiation exposures. This year EHS issued a total of 500 dosimeters to RSEC personnel and there were no exposures above unsafe levels. A follow up investigation was conducted as a result of a slight dose increase that occurred at the end of last year.

72

fixture in the laboratory, and individuals wear the others as they work in the lab. A total of 144 thermal neutron dosimeters were monitored with Training programs provided by EHS to the RSEC no indication of any measurable thermal neutron are license and regulatory driven. Training covering exposures to personnel. Self-reading dosimeters the requirement of shipping limited quantities of are issued to transient persons and visitors to the radioactive material was given to three reactor RSEC. The information for the temporary personnel this year. Also, approximately 44 new dosimetry is documented in logbooks maintained reactor personnel and students attended the by the administrative staff at the facility. radiation safety orientation. Required retraining for all radiation workers was provided to the Eric Boeldt, Penn State's radiation safety officer, RSEC by means of a newsletter distributed to all is a member of the Reactor Safeguards Committee. laboratory supervisors. Training is also offered Boeldt has taken an active role in the Safeguards annually to cover chemical and chemical waste Committee and has provided input regarding many handling requirements. All new employees and reactor safety issues brought to the committee's students attended this mandatory training.

floorthis year. Existing staff attended to meet the requirements for mandatory refresher training.

Additional Environmental Health and Safety support this year included an inspection of the storage tanks located at the Breazeale Nuclear Reactor. This inspection included three underground storage tanks (suspect, waste, and I . - , .' -,

process water tanks) as well as the above ground pure water storage tank. As a result of this inspection a process was implemented to help ensure the detection of any tank leaks. A Preparedness, Prevention and Contingency Plan (PPC) audit was conducted within the past year and the RSEC was found to be in compliance.

RSEC personnel also completed the annual chemical & chemical waste refresher training.

The chemical training program at the RSEC has a history of being in compliance with Penn State requirements. EHS also assisted the mechanical/nuclear engineering department with the development of a new chemical waste tracking system.

73

V I

is P I I

r i

,IL I, I ok I

I.

I11I Osarc II III 0 ' 1

,1,,

v~~~~~~~~~~ 1 0

11 P ~1.." I it -

'iil

' IF A J' si

.4

. II1 I i fI 10%

I

XI. RESEARCH AND SERVICE UTILIZATION Research and service continues to be the major focus of the RSEC. A variety of research and service projects are currently in progress as indicated on the following pages. The University-oriented projects are arranged alphabetically by department in Section A. Theses, publications, papers, and technical presentations follow the research description to which they pertain. In addition, Section B lists users from industry and other universities.

The reporting of research and service information to the editor of this report is the option of the user, and therefore the projects in Sections A and B are only representative of the activities at the facility.

The projects described involved 8 technical reports, presentations or papers, 26 publications, 6 master's theses, and 14 doctoral theses. The examples cited are not to be construed as publications or announcements of research. The publication of research utilizing the RSEC is the prerogative of the researcher.

Appendix A lists all university, industrial, and other users of RSEC facilities, including those listed in Sections A and B. Names of personnel are arranged under their department and college or under their company or other affiliation. During the past year, 49 faculty and staff members, 38 graduate students, and 9 undergraduate students have used the facility for research. This represents a usage by 13 departments or sections in 5 colleges of the university. In additions, 40 individuals from 24 industries, research organizations, or other universities used the RSEC facilities.

74

SECTION A. PENN STATE RESEARCH UTILIZING THE FACILITIES OF THE RADIATION SCIENCE AND ENGINEERING CENTER Anthropology Department MEETARHYOLITE USE IN THE ID-ATLANTIC DURING THE ARCHAIC-WOODLAND TRANSITION, 4,000-3,000 B.C.

Participants:

K. Hirth, Professor Greg Bondar, Ph.D. Candidate Services Provided: Neutron Irradiation, Radiation Counters, Laboratory Space Four thousand years ago, the Native American cultural continuum of the Mid-Atlantic and Northeastern regions of what is now the United States was apparently interrupted by the introduction of new and unique cultural practices. One diagnostic indicator of this discontinuity in the archaeological record across this region is the appearance of distinctive stone tools, popularly called "broadspears", which were often produced from an uncommon lithic material called metarhyolite. By using neutron activation analysis at Penn State's Breazeale Nuclear Reactor facility, we intend to chemically characterize (or "fingerprint")

geologic sources of metarhyolite to match broadspear-related artifacts to their sources of raw material. To date, over 300 samples from 31 individual quarries have been added to the database. This unprecedented research, combined with several other quantitative measurements of the artifacts, should help determine whether the distribution of this cultural material from Georgia to New England is due to a prehistoric migration of people, a transfer of cultural traits, or an in situ response to environmental perturbations occurring at the end of the third millennium, B.C.

In particular, artifacts from two sites were analyzed and compared to the existing database. The Mt. Aetna site in Washington County, MD, dates to the earlier Savannah River tradition, approximately 2,000 B.C.,

while site 36PE60 from Perry County, PA, dates from the later Susquehanna tradition, approximately 1,700 B.C. The fourteen Savannah River artifacts from the Mt. Aetna site traced to several different quarries in Pennsylvania and Maryland, except for one specimen which was most similar to source material in southern Virginia, approximately 250 miles away, as seen in Figure 1. In contrast, every one of the fourteen samples from the Susquehanna phase site in Perry County, PA, traced to the same quarry in southern Pennsylvania, as seen in Figure 2, the nearest source for this material. While these results are preliminary, they support the hypothesis that the earlier people of the Savannah River tradition used a variety of lithic sources, and were mobile, particularly from south to north. The results from the Susquehanna tradition suggest that they were more established, focused, or territorial on the landscape as expressed by their exploitation of a single distant lithic source. Our goal for the coming year is to complete the sampling of archaeological sites along a transect between the metarhyolite quarries in Maryland and those in southern Vrginia 75

Ph.D. Thesis:

Bondar, G.H., and K.G. Hirth, adviser. Tracing the Transitional: Examining Metarhyolite Use Along the Atlantic Seaboard During the Archaic-Woodland Transition. (In progress)

Publications:

Bondar, G. H., C. E. Donaldson, and T. H. Daubenspeck. Characterization and Sourcing of Metarhyolite in the Northeast. Paper presented at the 69b Annual Meeting of the Eastern States Archaeological Federation in Mt. Laurel, New Jersey, 2002.

10 1 + '+ t3 a To o, aUO-uknos + 41 B~

oUNSyRidge O PA

S nagiRidd, PA ACaoctn hlnMUDP

,W-III, O. MD

• Wfs.IA Rd, D MO C 0-_ W.UfllI.G.i&WlRd,MD

=Geasey C-/aill' "I AA,.,,y.,,ill, MD

• Cosd. HillRd. M0 Ul RPog.. VA Csdia SI. Bep. VA,NC Ot01- . , ., .I . . .. . . . . .

001 Cl 10 FUr.

Figure 1: Compositions of metarhyolite from the Mt. Aetna site in Washington Co, MD

,0

.1 tI I

+ . . I /; +

VA

+et+ tt

• . . -  :. - I-:

F~~~~~~~ S I p,' C.. PA

.. S..,, P.OI. PA

.S S.,AAa.". PA

. ,-aI.,

C

.C 5

- S.. Gv f o +4 NP C

vii 4-O1(1 HfI Figure 2: Compositions of metarhyolite.

76 C. v;

Biochemistry Department THE USE OF HIGH-ENERGY GANMA-IRRADIATION TO EFFECT CRYOREDUCTION OF METALLOENZYMiES FOR SPECTROSCOPIC CHARACTERIZATION.

Participants:

M.J. Bollinger, Jr., Associate Professor R.B. Guyer, Research Technician C. Krebs, Assistant Professor J.C. Price, Graduate Student L. Saleh, Graduate Student Service Provided: Gamma Irradiation Sponsor: Project (1) has been funded from a seed grant from the Innovative Biotechnology Research Fund of the Huck Institute for Life Sciences at Penn State to JMB and CK.

A grant was submitted to NIH (GM69657), which is currently being considered and received a score of 10.9 percent.

Project (2) is funded by grant GM 55365 from NIH to JMB ($ 157,500 per year).

Project (3) is a collaboration of Boi Hanh Huynh with CK and is supported by grant GM 47295 to BHH ($ 190,000 per year).

Enzymes containing metal ions are widespread in nature and play a pivotal role in almost every aspect of life; they catalyze numerous biochemical transformations, such as key steps in the biosynthesis of DNA and antibiotics. The main purpose of our research program is to define the mechanisms on a molecular level, by which metallo-enzymes catalyze these reactions. To accomplish this goal, we employ time-resolved spectroscopic methods with the aim to identify and characterize reaction intermediates and thereby deconvoluting the catalytic mechanism.

Significant information about such species can be gained from studies of samples that have been exposed to gamma-irradiation (total dose 2 to 5 Mrad) at low-temperatures (77 K), a.k.a.

'cryoreduction'. It has been demonstrated (Davydov et al. JACS 1994, 116, 11120-11128 and references therein) that this procedure allows reduction of the metal clusters while retaining the geometry of the oxidized cluster, because the molecular motion of the radiolytically reduced metal center is impeded due to the low temperature.

77

This method is extremely valuable for the study of diamagnetic species, because they can be converted to paramagnetic species, which can then be interrogated in detail by paramagnetic methods, such as EPR, ENDOR, ESEEM, and Mossbauer spectroscopies. We employ this methodology to study the following projects:

1) We have recently used this method for the initial characterization of the first reaction intermediate in a mononuclear non-heme Fe-enzyme. In particular, the assignment that this species contains formally a high-spin Fe(IV) center was made possible by this technique.

Additional information about the geometric and electronic structure will be obtained by the other, above-mentioned methods. Status: in progress

2) We have identified several peroxodiferric reaction intermediates in the reactions of non-heme diiron enzymes. Such species are believed to be key species in some of the non-heme diiron enzymes, and in order to gain insight into the reaction mechanisms detailed insight into the geometric and electronic structure is of high importance. We intend to employ the cryoreduction method to study the diamagnetic peroxodiferric species by the above paramagnetic methods. Status: in progress

3) In collaboration with Boi Hanh Huynh, Emory University, we will study the enzyme ferredoxin:

thioredoxin reductase, which contains an unusual iron-sulfur cluster. Again, we will attempt to convert the diamagnetic cluster to a paramagnetic cluster by cryoreduction and gain information about this species by the above methods. Status: in progress Ph.D. Theses:

John C. Price, and J. Martin Bollinger, Jr. (advisor) Mechanistic and Structural Studies on Taurine:a-Ketoglutarate Dioxygenase (In progress)

Lana Saleh, and J. Martin Bollinger, Jr. (advisor) Oxygen Activation and Electron Transfer in the R2 Subunit of Ribonucleotide Reductase from Escherichiacoli (In progress)

Publications:

Price, J. C., J.W. Barr, B. Tirupati, J.M. Bollinger Jr., and C. Krebs. The First Direct Characterization of a High-Valent Iron Intermediate in the Reaction of an m-Ketoglutarate-Dependent Dioxygenase: A High-Spin Fe(IV) Complex in Taurine/-Ketoglutarate Dioxygenase (TauD) from Escherichiacoli Biochemistry, 42, 7497-7508, 2003 Presentations:

J. M. Bollinger, Jr. Characterization of a High-Spin Fe(IV) Intermediate in the Reaction of Taurine/

Ketoglutarate Dioxygenase (auD). Invited talk at the 1 International Conference of Biological Inorganic Chemistry Cairns, Australia, July 2003 78

Price, J. C., E. W. Barr, B. Tirupati, J.M. Bollinger Jr., and C. Krebs. On the Identity of a Novel Fe(IV)

Intermediate in the Catalytic Cycle of Taurine/Ketoglutarate Dioxygenase (TauD). Poster presentation by J.C. Price at the 11 International Conference of Biological Inorganic Chemistry, Cairns, Australia, July 2003 Price, J. C., E. W. Barr, B. Tirupati, J.M. Bollinger Jr., and C. Krebs. Spectroscopic Characterization of a High-Spin Fe(IV) Intermediate in the Reaction of Taurine/Ketoglutarate Dioxygenase (TauD). Poster presentation by C. Krebs at the 1 International Conference of Biological Inorganic Chemistry, Cairns, Australia, July 2003 Biology Department GENETIC ANALYSIS OF THE DROSOPHILIA EYE DEVELOPMENT

Participants:

Z.C. Lai, Associate Professor M. Fetchko, Graduate Student Service Provided: Gamma Irradiation Sponsor: National Institutes of Health, $483,760 Notch signaling plays an important role in many biological processes, such as neurogenesis. Our research has been focused on how Notch signaling is regulated. Specifically, we hypothesized that a leucine-rich repeat (LRR) protein, Gpl50, is involved in modulating Notch activity to regulate eye development. Our current model is that Gp 150 acts in an endocytic pathway to facilitate Notch signaling.

Ph.D. Thesis:

Fetchko, M., and Z.-C. Lai, advisor. Molecular Genetic Analysis of Drosophila Eye Development:

Investigation of a Leucine-Rich Repeat Protein's Role in Cell-Cell Communication, 2002.

Publications:

Fetchko, M., W. Huang, Y. Li and Z.-C. Lai. DrosophilaGpl50 is Required for Early Ommatidial Development through Modulation of Notch Signaling. The EMBO Journal, 21: 1074-1083, March 2002.

Li, Y., M. Fetchko, Z.-C. Lai and N. E. Baker. Scabrous and Gp 150 are Endosomal Proteins that Regulate N Activity. Development, 130: 2819-2827, July 2003.

79

ORGANOGENEUS IN C. ELEGANS

Participants:

W. Hanna-Rose, Assistant Professor R. Sharma, Research Technologist H. Sun, Graduate Student Service Provided: Gamma Irradiation Sponsor: March of Dimes, $150,000 National Science Foundation, $360,000 Organ formation requires complex developmental coordination among groups of cells of various fates as they remodel themselves into functional structures. Additionally, strict coordination ofthe spatial development among organs is also essential for proper function. Our goal is to elucidate the molecular mechanisms controlling cellular remodeling during organogenesis and developmental coordination between organs.

We use development of the Caenorabditis elegans vulva and uterus as a model system, and we are studying the function of several genes in organizing the proper connection between these organs. We use gamma irradiation to create stable transgenic animals for numerous experiments to examine gene expression and function.

Ph.D. Thesis:

Hongliu Sun and Wendy Hanna-Rose (advisor). EGL-26 function in C. elegans vulva development. (in progress).

Civil and Environmental Engineering Department EFFECTS OF Zn(II), Cu(II), Mn(II), Fe(II), NO3 , or S0 4 2 at pH 6.5 AND 8.5 ON TRANSFORMATIONS OF HYDROUS FERRIC OXIDE (IFO) AS EVIDENCED BY MOSSBAUER SPECTROSPCOPY

Participants:

J. Jang, Graduate Student G. Catchen, Professor B. Dempsey, Professor W. Burgos, Associate Professor Service Provided: Angular Correlations Laboratory, Laboratory Space 80

The objective of the research is to determine the effects of transition metals on transformation of hydrous ferric oxide (HFO) into more thermodynamically stable ferric oxides. Ferric oxides are important environmental adsorbents. In anoxic environments, ferric oxides with Fe(ll) are important redox buffers.

Transformation of HFO to more stable phases can result in decreased surface area and reduced redox potential.

In some experiments, HFO was precipitated in the presence of Cu(fl), Zn(ll), Mn(II) and/or Fe(ll). In other experiments, Fe(H), NO3 -, and/or SO42- were added to pre-formed HFO. Transmission 57 Fe-Mossbauer spectroscopy was used to monitor the phase changes. At pH 6.5 and 65 C, HFO was transformed into hematite in the presence of Zn(HI) or Mn(ll). Both metals were significantly adsorbed for these conditions, occupying about 1.2 sorption sites per nm2 of HFO surface. Transformations were not observed at pH 6.5 in the presence of Cu(II), which was weakly adsorbed (0.06 sites per nm 2 ). No transformation occurred in the absence of Me(H) transition metals. At pH 6.5 and room temperature, HFO plus Fe(n) transformed into poorly crystalline goethite in the presence of chloride, into goethite and lepidocrocite in the presence sulfate, and into goethite and magnetite in the presence of nitrate. At pH 8.5 and room temperature, HFO that was formed with 0.033 or 0.33 mM Zn(II) and then aged with Fe(II) was transformed into magnetite that was depleted in octahedral Fe, i.e. non-stoichiometric or possibly mixed metal spinel, (Fe3 +)IV(Me"Fe2 + XFe0+)1O 4 . HFO that was aged with Cu(II) and Fe(II) was transformed into goethite and into magnetite that was also depleted in octahedral Fe. The transformations at pH 8.5 were completely inhibited by 3.3 mM Zn(II) and transformations were significantly decreased by 3.3 mM Cu(II). These results have extended observations of the transformation of HFO to neutral pH ranges and to lower concentrations of metals than previously reported.

Ph.D. Thesis:

Je-Hun Jang, "Chemistry of Environmentally Significant Phases of Oxides of Iron," Dept. of Civil and Environmental Engineering, The Pennsylvania State University, 2003.

Research Supervisor: Dr. Brian A. Dempsey Publications:

Jang, Je-Hun, Brian A. Dempsey, Gary L. Catchen, and William D. Burgos, "Effects of Zn(II), Cu(II),

Mn(II), Fe(I), NO3-, or So42- at pH 6.5 and 8.5 on Transformations of Hydrous Ferric Oxide (HFO) as Evidenced by Mossbauer Spectroscopy," Colloids and SurfacesA: Physicochem. Eng. Aspects, 221, 55-68 (2003).

81

Engineering Science and Mechanics Department STUDIES OF THE RADIATION RESPONSE OF A HIGH-K GATE DIELECTRIC/

SILICON SYSTEM: HfO2/Si

Participants:

A. Kang, Ph.D. Candidate P. Lenahan, Professor Service Provided: Gamma Irradiation Sponsor: NASA/Jet Propulsion Lab, $40,001 In collaboration with John F. Conley of Sharp Labs, Camas, Washington, we initiated a study of high-k dielectric/silicon systems. This work is relevant to NASA's interest in microelectronics, as future generations of low power CMOS technology will almost certainly utilize high-k dielectric oxides. This is so because the downscaling of SiO2 gate thickness reaches a fundamental physical limit at about 1.5 nm. The "leading candidate" high-k material in the literature is HfO2 . Arguably, the leading deposition technique is atomic layer deposition (ALD). Thus, we chose ALD HfO/Si systems for our initial investigations.

Unlike the conventional Si/SiO2 system, the HfO/Si interface dangling bond concentration does not increase when the devices are exposed to even quite high (>lOMrad) levels of 6Co irradiation. Capacitance versus voltage measurements also indicate very little interface trap generation. However, we find that irradiation generates significant densities (up to about 7x10'2 electrons/cm 2 ) of negative charge within the dielectrics.

Results of our initial investigation were presented at the 2002 Nuclear and Space Radiation Effects Conference. Our results were also published in the December 2002 issue of IEEE Transactions on Nuclear Science (see #8, publications).

Ph.D. Thesis:

Kang, A.Y., and P.M. Lenahan, adviser. Contributing to the Development of High-K Dielectric Technology by Identifying Defects Which Will Limit Device Performance, expected completion date: May 2005.

Publications:

Kang, A.Y, P.M. Lenahan, and J.F. Conley, Jr. "The Radiation Response of the High Dielectric Constant Hafnium Oxide/Silicon System." IEEE Trans Nucl. Sci. 49(6), 2636, Dec.2002.

82

Food Science Department CHARACTERIZATION OF GANIA IRRADIATION CHANGES IN MAJOR FOOD COMPONENTS BY VIBRATIONAL SPECTROSCOPY.

Participants:

J. Irudeau, Faculty Advisor R.Kizil, Ph.D. Student Services Provided: Gamma Irradiation Publications:

Kizil, R., and J.Irudayaraj. Discrimination of irradiated starch gels using Raman spectroscopy and chemometrics. Radiation Chemistry (Submitted) 2003.

Presentations:

Kizil, R., and J.Irudayaraj. Towards rapid monitoring of gamma irradiation damages in beef adipose tissues by FT-Raman spectroscopy. Presented in DC at the conference on Radiation at NIST, March 10, 2003.

Kizil, R., J. Irudayaraj, and K. Seetharaman. Spectroscopic characterization of native and irradiated starches and gels. Presented at the AACC meeting in Montreal, Nov 11-13, 2002.

83

Mechanical and Nuclear Engineering Department MONITORING AND CONTROL RESEARCH USING A UNIVERSITY RESEARCH REACTOR (PHASE IV)

Participants:

R.M. Edwards, Professor S. Cetiner, Graduate Assistant W. He, Graduate Assistant Z. Huang, Graduate Assistant Services Provided: Laboratory Space, Machine Shop, Electronic Shop Sponsor: DOE, $393,512 from 1999-2003 The project was conducted over the four year period from July 1, 1999 to June 30,2003. This interval incorporated a one year no-cost extension. Two PhD dissertations and two MS thesis projects resulted from this work. Other research publications numbered 30.

The existing hybrid simulation capability of the Penn State Breazeale nuclear reactor was expanded to conduct research for monitoring, operations and control. Hybrid simulation in this context refers to the use of the physical time response of the research reactor as an input signal to a real-time simulation of power-reactor thermal-hydraulics which in-turn provides a feedback signal to the reactor through positioning of an experimental changeable reactivity device (ECRD). An ECRD is an aluminum tube containing an absorber material that is positioned in the central thimble of the reactor by an external computer-driven algorithm. Simulation of parallel boiling channels and modal reactor kinetics were used to expand the hybrid reactor simulation (HRS) capability to include out-of-phase stability characteristics observed in operating BWRs.

The Penn State thernal-hydraulic test loop was constructed to mimic the boiling phenomena of a Simplified Boiling Water Reactor (SBWR), an advanced reactor design concept, in a unique atmospheric pressure facility where flow visualization is afforded by borosilicate glass piping. Electrically heated rods take the place of the nuclear reactor fuel. A hybrid loop simulation capability (HLS) was added to this facility where the physical thermal-hydraulic time response of the test-loop provides feedback to a reactor kinetics simulation whose power response generates a signal to drive the electrically heated rods.

Furthermore, the hardware and software protocols to electronically couple the research reactor and testloop (HRLS) were developed where the reactor response could provide a signal to drive the electrically heated rods in the testboop and the boiling response of the testloop could provide a feedback signal to position the ECRD in the research reactor.

84

FINAL PHASE 4 The results of the first three phases of the project were summarized in previous RSEC progress reports. The final Phase 4 was originally scheduled for the one-year period from July 1, 2001 to June 30,2002. The project incurred an unforced change of scope through the failure of a major piece of experimental equipment in 2002. A recovery procedure was completed in December 2002 and operation of the loop to complete Phase 4 was conducted until April 2003. At that time, another malfunction occurred where only 3 of the 12 electrically heated rods were available. Three-rod operation does not provide enough heat input to develop two-phase conditions in a reasonable time due to heat losses from the system. The Mechanical and Nuclear Engineering Department provided funds to have the bundle dismantled and rebuilt using professional engineering services. As of the end of September 2003, the reconstructed bundle is ready for reinstallation. Future operation of the loop is planned as part of the required senior nuclear-engineering laboratory course in Experiments in Reactor Physics.

The original phase 4 description is: Phase 4 was to have a duration of 12 months. The goals of this phase were a) implement the hybrid reactor testloop simulator capability with optional modal kinetics and parallel boiling channel simulations; b) design and implement flow control incorporating a jet-pump for the SBWR testloop; c) develop wide-range automated control of BWR incorporating optimized-feedforward and robust feedback control; d) evaluate automated wide-range ABWR control in the hybrid simulation environment.

Phase 4 goal a) was concluded with the development of the computer hardware and software to implement the hybrid reactor testloop simulator. Phase 4 goal b), design and implementation of flow control, resulted in the addition of a motorized valve to restrict flow because the natural circulation driving force was found to be more than sufficient to provide cooling for the facility's power level.

Dynamic manipulation of the valve position was sought to stabilize the flow. Phase 4 goal c) has been completed in the theses and publications of Shyu [2, 8, 30]. Phase 4 goal d) could not be completed within the one-year no-cost extension because of the malfunctions and repairs of the test-loop. Furthermore, operation of the test-loop in a stable manner could not be reliability duplicated.

However, goal c) included simulation validation for an ABWR.

During the periods when the loop when was unavailable, alternative supporting research was conducted in two areas: 1) the development of additional ABWR control approaches and 2) stability analysis of low-pressure two-phase systems. The additional ABWR control approaches include multivariable fuzzy-logic control (FLC) and fuzzy adapted recursive sliding mode control (FARSMC) in the MS Thesis and PhD dissertation of Huang [3, 4, 23, 27, 29, 34]. The adaptation of these advanced control techniques for the desired experimental validation in the HRLS is still hampered by the inability to reliability operate the loop in a stable manner; thus, a major effort was initiated to develop stability analysis of the testloop, which is expected to lead to another dissertation. The goal of stability analysis is to identify facility and procedure modifications to obtain more predictable stable operation.

85

CONCLUSION:

The DOE Instrumentation, Controls, and Human Machine Interface (IC&HMI) Technology workshop was conducted in May 2002 to examine IC&HMI needs in the design of Nuclear Power 2010 and Generation IV programs. A conclusion identified demonstration facilities as the most important research objective. Research and education for advanced monitoring and control usually fails to take into account real-world characteristics of physical systems, instrumentation and digital implementation. The availability of appropriate experimental facilities and personnel to conduct sophisticated experiments therefore limits the opportunity to develop advanced control techniques to enhance safety and economy in future nuclear power plants.

This NEER project addressed these issues by expanding existing experimental-neutronics advanced-control capability to include experimental capability with a boiling-regime thermal-hydraulic test-loop and a coupled neutronics thermal-hydraulic physical system. Research on advanced control and stability analysis and monitoring was undertaken.

The benefits of a successful hybrid simulation testbed, with demonstrated capability to validate monitoring and control techniques, could be multiplied in future years to allow remote access to researchers from other institutions via advanced communication capabilities that are now becoming available via internet-2.

PROJECT BIBLIOGRAPHY FOR DE-FG07-99ID13778:

Note: Theses, Publications, etc. are listed below for entire four year project, but only items not listed in previous reports are reported in the 02-03 totals in the Chapter XI Introduction.

Theses:

1. Roman Shaffer, "Design, Simulation, and Validation of Robust Controllers", a Masters Thesis in Nuclear Engineering, The Pennsylvania State University, May 2000.

2. Shian-shing Shyu, "A Robust Multivariable Feedforward/Feedback Controller Design for Integrated Power Control of Nuclear Power Plant", A Dissertation in Nuclear Engineering, The Pennsylvania State University, May 2001.

3. Zhengyu Huang, "Fuzzy Logic Controller Design for Overall Control of a Nuclear Power Plant",

A Masters Thesis in Electrical Engineering, The Pennsylvania State University, August 2001.

4. Zhengyu Huang, "Fuzzy Adapted Sliding Mode Controller Design for a Nuclear Power Plant", A Dissertation in Nuclear Engineering, The Pennsylvania State University, May 2002.

86

Publications:

5. R.M. Edwards. Expansion of a Testbed for Advanced Reactor Monitoring and Control. Trans.

of the Amer Nucl. Soc. 82:78-80. San Diego, CA, June 2000.

6. Cecefias-Falc6n, M., and R.M. Edwards. Stability Monitoring Tests Using a Nuclear-Coupled Boiling Channel. Nuclear Technology. 131:1-11, July 2000.

7. Ceceilas-Falc6n, M., and R.M. Edwards. Out-of-Phase BWR Stability Monitoring. Proceedings of The Third American Nuclear Society International Topical Meeting on Nuclear Plant Instrumentation, Control and Human-MachineInterface Technologies, NPIC&HMIT'2000, 9 pages on CD ROM. Washington, DC, November 2000.

8. Shyu, S., and R.M. Edwards. Optimized-Feedforward and Robust-Feedback Used in Integrated Automatic Reactor Control. Proceedingsof The ThirdAmerican Nuclear Society International Topical Meeting on Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies, NPIC&HMIT'2000, 8 pages on CD ROM, Washington, DC, November 2000.

9. He, W., Z. Huang, and R.M. Edwards. Experimental Validation of Optimized-Feedforward Control for Nuclear Reactors. Proceedingsof The ThirdAmerican NuclearSociety InternationalTopical Meeting on Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies, NPIC&HMIT'2000, 8 pages on CD ROM, Washington, DC, November 2000.

10. Huang, Z., and R.M. Edwards. Hybrid Reactor Simulation of BWR Using a First Principle Boiling Channel Model, Proceedings of The Third American Nuclear Society International Topical Meeting on Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies, NPIC&HMIT'2000, 8 pages on CD ROM, Washington, DC, November 2000.

11. Shaffer, R., W. He, and R.M. Edwards. Experimental Validation of Robust Control for Nuclear Reactors. Proceedings of The Third American Nuclear Society InternationalTopical Meeting on Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies, NPIC&HMIT'2000,9 pages on CD ROM. Washington, DC, November 2000.

12. Edwards, R.M., Z. Huang, and W. He. Integration of a Thermal-Hydraulic Test-loop and University Research Reactor for Advanced Monitoring and Control Research, Proceedings of The Third American Nuclear Society International Topical Meeting on Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies, NPIC&HMIT'2000. 8 pages on CD ROM, Washington, DC, November 2000.

13. Huang, Z., and R.M. Edwards. BWR Hybrid Reactor Simulation Using an Experimental Changeable Reactivity Device. Trans. of the Amer Nucl. Soc. Student Conference, Raleigh, NC, 1 page, 2000.

14. Shaffer, R.A., and R.M. Edwards. Robust Reactor Control for Autonomous Systems. Trans. of the Amer Nucl. Soc. 82:75-76. San Diego, CA, 2000.

87

15. R.M. Edwards. Expansion of a Testbed for Advanced Reactor Monitoring and Control. Trans. of the Amer Nucl. Soc. 82:78-80. San Diego, CA, 2000.

16. Huang, Z., and R.M. Edwards. Simulation of BWR Out-of-Phase Oscillation Using a University Research Reactor, Trans. of the Amer Nucl. Soc. Student Conference, College Station, TX, 7 pages on CD ROM, 2001.

17. He, W., and R.M. Edwards. Robust Design an Evaluation of On-line Uncertainty Monitoring System on a Reactor, Trans. of the Amer Nucl. Soc. Student Conference, College Station, TX, 6 pages on CD ROM, 2001.

18. Cetiner, M., and R.M. Edwards. The Pennsylvania State University Low Pressure Integral Test Facility Data Acquisition System and User Interface, Trans. of the Amer Nucl. Soc. Student Conference, College Station, TX, 7 pages on CD ROM, 2001.

19. Huang, Z., and R.M. Edwards. Hybrid Reactor Simulation and 3-D Information Display of BWR Out-of-Phase Oscillation, Trans. of the Amer Nucl. Soc. 84:99-100, Milwaukee, WI, 2001.

20. He, W., and R.M. Edwards. Evaluation of a Reactor On-Line Uncertainty Monitoring System, Trans. of the Amer Nucl. Soc, 84:111-112, Milwaukee, WI, 2001.

21. Cetiner, S.M., L.E. Hochreiter, R.M. Edwards, W. He, and Z. Huang. Two-Phase Natural Circulation Experiments in The Penn State Low-Pressure Integral Test Facility, Trans. of the Amer Nucl. Soc, 85:311-333, Reno, NV, 2001.

22. Cecefias-Falc6n, M., and R.M. Edwards. Application of a Reduced Order Model to BWR Corewide Stability Analysis, Annals of NuclearEnergy, 28:1219-1235, 2001.

23. Huang, Z., and R.M. Edwards. ABWR Plant Overall Control Using Fuzzy Logic Control Technique, Trans. of the Amer Nucl. Soc, 86:180-182, Hollywood, FL, (First author supervised by candidate) 2002.

24. Cetiner, S.M., and R.M. Edwards. Integration of a Thermal-Hydraulic Test Loop and University Research Reactor For Advanced Control, Trans. of the Amer Nucl. Soc. 86:195-196. Hollywood, FL, (First author supervised by candidate) 2002.

25. He, W., and R.M. Edwards. Evaluation of in-phase BWR Stability Monitor with a Hybrid Reactor Facility, Trans. of the Amer Nucl. Soc, 86:242-243, Hollywood, FL, (First author supervised by candidate) 2002.

26. He, W., Z. Huang, and R.M. Edwards. Advanced BWR Stability Monitoring Tests with a Hybrid Reactor Facility, Proceedings of American Nuclear Society Topical Meeting, International 88

Congress on Advanced Nuclear Power Plants (ICAPP), 6 pages on CD ROM, (First author supervised by candidate) 2002.

27. Huang, Z., and R.M. Edwards. Sliding Mode Control Application in ABWR Plant Pressure Regulation, Proceedingsof American Nuclear Society Topical Meeting, InternationalCongress on Advanced NuclearPower Plants (ICAPP), 8 pages on CD ROM, June 2002.

28. Cetiner, S.M., and R.M. Edwards. Results of Coupling a Thermal-Hydraulic Test Loop and University Research Reactor, Proceedingsof American Nuclear Society Topical Meeting, International Congress on Advanced NuclearPower Plants (ICAPP), 7 pages on CD ROM, 2002.

29. Huang, Z., K.Y Lee, and R.M. Edwards. Fuzzy Logic Control for Nuclear Power Plant Overall Control, Proceedingsof 15th IFAC World Congress, Barcelona, Spain, 6 pages on CD ROM, 2002.

30. Shyu, S., and R.M. Edwards. A Robust Multivariable Feedforward/Feedback Controller Design for an Integrated Power Control of Boiling Water Reactor Power Plants, Nuclear Technology, 140:129-146, 2002.

31. Cecefias-Falc6n, M., and R.M. Edwards. Out-of-Phase BWR Stability Monitoring, Nuclear Technology, 143: 125-131, 2003.

32. Huang, Z., and R.M. Edwards. Hybrid Reactor Simulation of BWR Power Oscillations, Nuclear Technology, 143:132-143,2003.

Manuscripts accepted:

33. Shaffer, R., W. He, and R.M. Edwards. Design And Validation Of Optimized Feedforward With Robust Feedback Control of A Nuclear Reactor, Submitted December 2001 for publication in Nuclear Technology.

34. Huang, Z., R.M. Edwards, and K.Y Lee. Fuzzy Adapted Recursive Sliding Mode Controller Design for a Nuclear Power Plant Overall Contol, Submitted August 2003 to IEEE Transactionson Control Systems Technology.

89

NE 444, REACTOR OPERATIONS LABORATORY

Participants:

C.F. Sears, Professor and Director B.J. Heidrich, Research Assistant G.M. Morlang, Reactor Engineer C.C. Davison, Research and Education Specialist Graduate and Undergraduate Students The Nuclear Engineering 444 Laboratory Course is a one credit applied laboratory course taken by both graduate and undergraduate students. It provides a hands-on experience with the students as operators of the Penn State Breazeale Reactor under the oversight of a licensed NRC Senior Reactor Operator. Upon completion of the course each student will have over 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> of actual reactor operations experience. Using the TRIGA reactor as a teaching tool the students are taken through a series of successive laboratory exercises which build upon their classroom learning and the preceding reactor exercises. Material and operations covered include reactor operating and support systems, technical specifications, operating procedures, startups, power changes, reactivity measurements, heat transfer, instrumentation, transient operations including pulses and square waves, power coefficient measurements, log keeping, and operating predictions including critical rod positions and Xenon poisoning effects. They are also introduced to self checking systems as well as two- and three-way communications.

During each laboratory session the operations and measurements being performed by the students are related to similar evolutions for power and test reactors as well as developing reactor concepts. The students prepare laboratory reports in a manner consistent with that which they would be expected to use as engineers in describing industrial investigations. Upon completion of the course each student is tested using an operations evaluation and a written exam. The evaluation and exam assure that the students can apply in a practical manner the analytical skills they have been learning in other nuclear engineering courses.

NE 451, UNDERGRADUATE LABORATORY OF REACTOR EXPERIMENTS

Participants:

R.M. Edwards, Professor M.E. Bryan, Research Engineer T.L. Flinchbaugh, Manager, Operations and Training B.J. Heidrich, Research Assistant C.F. Sears, Director Services Provided: Laboratory Space, Machine Shop, Electronics Shop, SUN SPARC Server Computer System, Neutron Irradiation Using Subcritical Pile, Reactor Instrumentation and Support Staff 90

The Nuclear Engineering 451 course is the second of two 3-credit laboratory courses required of all Penn State Nuclear Engineering undergraduates and is typically taken during the Fall of the senior year. Each weekly laboratory exercise usually consists of two lectures and one laboratory session. By the beginning of the senior year, the students have already covered the LaMarsh Introduction to Nuclear Engineering text including reactor point kinetics. The 451 course emphasizes experiments using the instrumentation that was covered in NucE 450 and is divided into two (more or less) equal "tracks". These tracks can be coarsely described as TRIGA and non-TRIGA experiments and each is the major responsibility of a different professor. The non-TRIGA track includes three graphite pile, two reactor operation experiments and a xenon poisoning simulation. In 2000, the TRIGA track included:

1. Digital Simulation of TRIGA Reactor Dynamics

2. Large Reactivity Insertion (Pulsing)

3. Control Rod Calibration

4. Reactor Frequency Response

5. Neutron Noise

6. Reactor Control This sequence was first introduced in 1991, when the reactor control experiment replaced a reactor gamma field measurement experiment and the digital simulation exercise was modified to point kinetics from its previous focus on Xenon dynamics. The laboratory utilizes Macintosh computers with GW Electronics MacAdios Jr. data acquisition hardware and Superscope II software. The Superscope II software was a major software upgrade for 1993, and with its new point-by-point seamless mode enabled effective reactivity calculations and control experiments.

The Mathworks SIMULINK simulation software was used for the digital simulation exercise for the first time in 1992. Reactor control is offered as a graduate course in our department but until 1991, our undergraduates did not receive a complete introduction to feedback control. In the Fall of 1994, a new UNIX network compatible control system was utilized for the reactor control experiment. The new system was also acquired to enhance the NSF/EPRI sponsored research and is described in more detail in subsequent sections. The UNIX Network compatible controller programming is performed using the Mathworks SIMULINK block programming language in a SUN SPARC workstation. An automatic C code generation process produces and downloads the necessary real-time program for execution in a microprocessor-based controller with an ETHERNET network interface to the host workstation.

The 1994 version of the control experiment thus unified all of the MATLAB/ SIMULINK instruction earlier in the course into a demonstration of state-of-the-art CASE-based control system design and implementation. In 1998, the UNIX network compatible control system was made obsolete by the availability of a Windows NT implementation of the MathWorks SIMULINK environment. The Windows NT platform became available as a result of the DOE NEER grant project on "Monitoring and Control Research Using a University Research Reactor" described elsewhere in this report.

91

ANALYZING SOFT ERROR RATES IN SEMICONDUCTOR MEMORIES AND FIELD PROGRAMMABLE GATE ARRAYS

Participants:

V.Narayanan, Assoc. Prof.

M. J. Irwin, Prof.

K. Unli, Prof.

V. S. R. Degalahal, Grad Student S. Cetiner, Grad Student Services Provided: Neutron Beam Laboratory Sponsor: DOE, Innovations in Nuclear Infrastructure and Education (INIE), Big-Ten Consortium Mini Grant Program Project

Description:

Soft errors are transient circuit errors due to excess charge carriers induced primarily by external radiations. Radiation directly or indirectly induces a localized ionization that can flip the internal values of the memory cells. The flipping susceptibility of SRAM memory cells depends on the charge stored in the memory node and the number of particle strikes that induce sufficient charge to flip the stored charge. With the continued reduction of nodal capacitances and supply voltages to the memory cells, the charge required to flip the bits stored in memory is continuously decreasing. This observation coupled with the increasing size of on-chip memory elements makes soft errors a major reliability concern. Reliability concerns are projected to be among the most significant roadblocks facing the semiconductor industry as documented in the latest version of the International Technology Roadmap for Semiconductors. Exacerbating the soft error problem are various recently proposed leakage power mitigation techniques that modify the circuit structure and scale the supply voltage during operation. We expect to work with our industry colleagues in Intel, IBM and Xilinx in obtaining samples for testing as well as sharing results of our tests. The goal of this project is to provide a better understanding of the tradeoffs between soft errors and low power optimizations. We plan to characterize the potential increase in soft error rates as process technology scales (today's 130nm to 70nm and below) and study how soft error rates are affected by low power optimizations. The results will provide insight into circuit, architectural and system approaches that can be used to provide reliable systems in the face of increasing soft error rates. Specifically, we plan to perform the following experiments Use thermal neutrons from the Breazeale nuclear reactor to investigate the impact of soft errors on memory elements. The experimental setup will initialize the memory with a specified data pattern and will be followed by exposure to the neutron beam. This will be followed by reading the data pattern from the exposed memory to find the number of bits that are flipped due to the radiation. The experiment will involve various parameters including - Changing the reactor power ranging from I KW to 1000KW which will vary the flux of the neutron. The goal is to quantify the relation between flux and soft error rates. - The target memory design will be selected from different process technologies supporting different features sizes and circuit styles. This will be used to predict the soft error problems in future designs. Different supply voltages will be selected 92

for the memory cells when performing the experiments in order study the impact of supply voltage scaling, a widely used power optimization technique, on soft error rates. - Different packaging choices will be used for memory elements selected to study the influence of packaging technology on soft error rates A similar set of experiments will then be performed using Field Programmable Gate Arrays (FPGAs) that use distributed memories unlike the normal memory elements The results from these experiments will be of significant importance to the chip design industry. The quantification of the influence of different layout, circuit, process and operational parameters on soft error rates using our experiments can be used to build a model that would permit designers to easily plug and play parameters for evaluating the impact of their design decisions on SER. Eventually, such a model can be incorporated into commercial tools such as layout extractors or memory synthesizers to estimate/generate reliability conscious designs. The availability of such models is of critical importance to the future success of semiconductor industry. This project builds on the ongoing efforts of the researchers in the Computer Engineering (Drs. Narayanan and Irwin) on soft error and low power design and the expertise of Dr. Unlu in nuclear engineering.

Status:

Experimental memory chips that will be exposed to radiation have been selected and ordered. The radiation setup at the nuclear plant has also been devised. The memory chips include both custom made and commercial chips. The custom-made chip is made from an advance 130nm process and, operates at V and 200mV (in low power mode). 9 commercial chips from 6 different vendors are chosen for the test. All these chips are SRAM based memories, working under different operating voltages and manufactured under different process. Most of these chips support a low power consumption mode. These chips span a few technology generations, thus giving us a good mix of the whole spectrum. The next step requires integration of these chips onto a PCB with interconnects to the chip and supporting power supplies. The PCB currently focuses on the simplest implementation to speed up the process. The approach envisioned is to "drive" the memory chip from a commercial digital 1/0 card hosted by an IBM PC since no "high speed" 1/0 is required for the initial research, at this time. Higher speed testing of the memory under operational I/O conditions may be a later objective.

Of course, this all implies a second generation of the target PCB. Engineering Design Services of College of Engineering, Penn State, are handling the current implementation of the PCB. Tentatively, the board is slated to be ready for testing by the late of November 2003. A Field Programmable Gate Array board has also been ordered for performing a different set of tests.

We believe the current effort will help us understand the correlation between power consumption and reliability of semiconductor memories. Currently, power consumption and soft errors are considered among the biggest challenges confronting the semiconductor industry. The support obtained from DOE, INIE, Big-1O Consortium Mini Grant Program has been vital in distinguishing this effort and attracting attention from industry to this work due the experimental part in a nuclear facility.

Relevant Publications:

see (http://www.cse.psu.edu/-mdl/softerrors.html) 93

MODELING OF EXISTING BEAM-PORT FACILITY AT PENN STATE UNIVERSITY BREZEALE REACTOR USING MCNP

Participants:

F. Alim, Grad Student B. Sarikaya, Grad Student Y Azmy, Prof.

J. Brenizer, Prof.

K. Ivanov, Assoc. Prof.

K. Unli, Prof.

Services Provided: Neutron Beam Laboratory Sponsor: DOE, Innovations in Nuclear Infrastructure and Education (INIE)

Introduction The Radiation Science and Engineering Center (RSEC) facilities at The Pennsylvania State University (PSU) include the Penn State Breazeale Reactor (PSBR), gamma irradiation facilities, and various radiation detection and measurement laboratories. The PSBR is the nation's longest continuously operating reactor that went critical in 1955. The PSBR is a 1 MW, TRIGA with moveable core in a large pool and with pulsing capabilities. The core is located in a pool of de-mineralized water.

When the reactor core is placed next to a D 2 0 tank and graphite reflector assembly near the beam port locations, thermal neutron beams become available for neutron transmission and neutron radiography measurement from two of the seven existing beam ports (BP).

When the PSBR reactor was built MTR type fuel elements with active length of 24" were used. With the MTR fuel the beam port arrangement did not limit the maximum neutron output. In the mid 60's the PSBR was converted from MTR type to TRIGA type fuel (active length of TRIGA fuel is 15").

With TRIGA fuel, only one beam port is at the centerline of the core active area, four beam ports are five inches below the centerline and two are eleven inches below the centerline (below the active fuel region). Only two beam ports are currently being used. BP #4 which is located axially at the centerline of the reactor core is used for research, primarily neutron radiography and radioscopy, and BP #7 with its lower neutron flux level is used for service activities involving neutron transmission measurements. Due to inherited design issues with the current arrangement of beam ports and reactor core-moderator assembly, the development of innovative experimental facilities utilizing neutron beams is extremely limited. Therefore, a new core-moderator location in PSBR pool and beam port geometry needs to be determined in order to build useful neutron beam facilities. A study is underway with the support of DOE-INIE funds to examine the existing beam ports for neutron output and to investigate new core and moderator designs that would be accessible by new additional beam ports.

94

Description of Work Core calculations are performed by using the diffusion code ADMAC-H [ 1], which utilizes a few-group cross-section library developed with HELIOS [2]. Since the geometrical and material configuration of the beam-port facility is complex the MCNP [3] code is used instead of the deterministic codes because of its geometrical flexibility. An interface program has been developed at PSU to link the diffusion code to the neutron transport code. This interface basically reads the ADMARC-H output then computes the source term for MCNP and finally prepares the necessary MCNP input card at the requested format. Fig. I shows the schematic view of the overall simulation.

The reactor core model used for this simulation is given in Figure 2. This model includes also the D20 tank reflector.

Core

, aiModel ZZA AR .~ HM CN P Fig. 1. The schematic view of the simulation package Fig. 2. The core model The ADMARC-H Model The PBSR TRIGA core was first loaded in 1965. Currently, the PBSR is operated using core cycle 51 and the simulation core model is based on this configuration of the core. The model has been validated using measured data from TRIGA. The uniform lattice in PBSR is formed in hexagonal shape. The center of the core is the location of the central thimble (the water rod), which is surrounded by hexagonal rings. There are 94 fuel rods; 30 of them are 12 wt% and 64 of them are 8.5 wt%, both with a 20 wt% uranium-235 enrichment. Three control rods (shim, regulating and safety) are fuel follower control rods driven by motor. They are composed of graphite at the top and bottom, fuel and absorber (borated graphite) in the middle. The fourth control rod is the transient rod (air rod), the only control rod without fuel material driven by an electro-pneumatic during the steady-state operation.

The core model also includes the D 7O reflector.

The MCNP Model The MCNP model consists of the D 2 0 tank and the beam port tube with their surroundings. Preliminary runs showed that modeling of the whole system with MCNP is computationally very expensive.

Therefore, the overall MCNP model is broken up into two parts, namely a D 2 0 tank model and a beam-port model. The MCNP part of the simulation is performed in two steps. First, the DO tank model, which contains the source information from the interface code and geometry data for the D 20 tank is run. Then, the output of the D 2 0 tank model is used as the input for the beam-port model. Finally the beam-port model is run with this input data.

95

Results and Discussion The neutron spectrum at the exit of BP#7 was measured using a single disk neutron chopper at 1 MW reactor power [4]. We modeled the core, D 2O tank and beam-port by using the PSU simulation package shown in Fig. 1 The measured neutron spectrum is compared with the result of the model simulated with our package in Fig.3.

• 250E0u A Fig. 3. Comparison of the results of beam-port model with the experimental data Conclusions The preliminary results show very good agreement with the experimental data. In order to further test the accuracy of the intermediate calculations performed in between two MCNP calculational steps, a full model case is also being performed.

References

1. Ivanov, K., N. Kriangchaiporn. "ADMARC-H Manual", The Pennsylvania State University, 2000.

2. "HELIOS Methods", StudsvikScandpower, 2000.

3. X-5 Monte Carlo Team. "MCNP - A General Monte Carlo N-Particle Transport Code, Version 5, Volume I: Overview and Theory", LA-UR-03-1987, April 24,2003.

4. J. H. J. Niederhaus. "A Single-Disk-Chopper Time-of-Flight Spectrometer for Thermal Neutron Beams," M. Sc. Thesis, The Pennsylvania State University, August 2003.

96 C-15

THERNIAL-HYDRAULIC BEHAVIOR OF THE PENN STATE BREAZEALE NUCLEAR REACTOR (PSBR)

Participants:

J.E. Chang, Research Assistant L.E. Hochreiter, Professor T.F. Miller, Research Associate Services Provided: Reactor Pool, Machine Shop Sponsor: Radiation Science and Engineering Center, PSU

SUMMARY

The objective of this project is to develop thermal-hydraulic model for the Pennsylvania State University Breazeale Nuclear Reactor (PSBR). The PSBR core is located in a large pool and is cooled by natural circulation, which is induced by the thermal expansion of the coolant. The earlier experiment showed that the PSBR core is mainly cooled by a strong cross-flow rather than an axial flow. The interaction between the Nitrogen-16 (N-16) jet flow and the buoyancy induced flow makes it complicated to measure or analyzed the flow distribution in the PSBR pool.

The thermal-hydraulic model for the PSBR was being developed including a computational fluid dynamics (CFD) model and a stand-alone fuel rod model. The CFD model showed the flow distribution in the PSBR pool including the velocity and temperature profiles. This model explains the strong cross-flow comes through the edge of the PSBR core, which is observed by the previous experiment. It also indicates the flow stagnation below the core and the flow path of the cold coolant from the small pool along the aluminum gate. In order to compare with the experiment data in 1970s, the neutronics calculation and the CFD calculation were performed. The estimated neutron flux distribution gives more accurate temperature distribution of the coolant channels compared with the experiment data. The stand-alone fuel rod model was being developed and used to predict the temperature response of a PSBR fuel rod during the pulsing and steady-state operations. The fuel rod model represents the temperature profile inside a fuel rod for the steady-state and the transient behavior during the different reactivity insertions.

The flow and temperature measuring experiment is being proposed for the proceeding work. An insertion flow meter will measure the flow velocity around the PSBR core. A series of thermocouples will determine the PSBR coolant temperature including the core channel and the pool. Two different thermocouple probes will be used: one will be inserted inside the PSBR core through the coolant channel and the other will be located in the PSBR pool for the pool temperature.

97

INTRODUCTION There are several unsuccessful attempts to model the flow distribution in the PSBR pool. The previous experiments showed that the unique temperature profiles along the coolant channels. Below the center of an active fuel rod, all the temperatures of the coolant are almost identical even different locations. However, the temperature decreases above the two-thirds (2/3) height of an active fuel rod.

Three thermocouples are installed inside an instrumented TRIGA fuel rod, so the fuel temperature can be measured by the real-time monitoring system of the reactor. Haag (1971) calculated the radial temperature distribution of a fuel rod using FORTRAN IV. The general heat conduction equations describe the temperature profile during steady state operation even if the heat generation rate comes from a core-wide homogenized result. Gouger (1997) used a 3-D neutronics code, STAR (Space-Time Analysis of Reactor),

and a 3-D thermal-hydraulics code, COBRA-IV (Coolant Boiling in Rod Arrays-Version IV), to try to describe the flow field in the core. He could explain the temperature profile in the fuel rods within 17 %

variance. However, his results do not correctly represent the coolant temperature behavior. COBRA-IV was developed for the steady-state and transient operations of commercial reactors. The axial velocity is much more dominant than the lateral velocity in a typical power reactor, which is cooled by forced circulation.

The code depends on highly empirical correlations among adjacent channels for across-flow, so it can not really represent the pool boundary conditions, i.e., zero velocity.

In contrast to the fuel rod temperature, the coolant temperature has not been well explained or modeled.

Haag (1971) measured the coolant temperature inside the PSBR core using a thermocouple inserted through the flux holes on the upper grid plate. The channel L is located near the center of the core (between the B ring and the C ring of the fuel rods). The channel P is the farthest from the center. In Haag's experiment, he observed cyclic variations of the temperature reading.

The temperature profile shows a unique behavior along a channel. Below the center of an active fuel rod, all the temperatures of the coolant are almost identical even in all four core locations. The channel coolant temperature decreases above the two-thirds (2/3) height of an active fuel rod at all four locations. The explanation of this behavior is that a strong cross-flow comes through the edge of the PSBR core, turns and goes up along the fuel rods in Figure 1. Since the bottom grid plate has very small size of holes, most coolant comes from the edge of the PSBR core.

98

E -

n1Uj I

'-1 II

] 7-1

-A I 11I Figure 1. Expected flow path near the PSBR core (core front face)

FLOW-3D ANALYSIS It is necessary to obtain the neutron flux distribution in 1970s since the fuel loading has been changed several times. Especially the higher weight percent fuel rods (12.0 w/o) has been installed since 1972. The power distribution and the fuel bumup can only be estimated from the operation history of the PSBR and limited numbers of documentations. However, the averaged burnup was used for the 3-D neutronics calculation since there is not enough information for the pin-by-pin burnup history of the PSBR core.

Figures 2 through 5 show the CFD results using 1970s data along the coolant channels. The solid line shows the CFD prediction and the scattered points represent the measured data with temperature fluctuations during the experiment in 1970s. The results of channels L and M represent very good agreement on the measured data in Figures 2 and 3. The axial flow is dominant rather than the cross-flow near the center of the PSBR core. However, the results of channels N and P show a little underestimation of temperature distribution around the mid point of an active fuel rod in Figures 4 and 5. The temperature predictions of bottom and top coolant channels are very good. It is believed that the cross-flow model in FLOW-3D slightly overestimates the flow velocity near the edge of the core. Since the flow area near the core edge is larger than inside the core, a small overestimation offlow velocity results in an underestimation of temperature profile.

99

Temperature Profile along the L Channel so 70 60 e!!

0 50 8 3 20 30 20

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 Axial Position [z/LI Figure 2. Temperature profile along the L channel Temperature Profile along the M Channel 80 -

70 60-e i 50_

E 40 30 20

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 Axial Position [zt]

Figure 3. Temperature profile along the M channel 100

Temperature Profile along the N Channel 80 70 60 SO 7-E 40 30 20-i'

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 Axial Posson [z/l]

Figure 4.' Temperature profile along the N channel Temperature Profile along the P Channel 80 l l l 70 60 e

0L.

50 ED I-40 30 }

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 Axial Position izf1 Figure 5. Temperature profile along the P channel 101

The stand-alone fuel rod code has been used to calculate the temperature distribution of a PSBR fuel rod during the 1MWth steady-state operation. The temperature profile inside a PSBR fuel rod is represented in Figure 6. The maximum temperature of a fuel rod is predicted as 492.7 OC, which is within a 3.1%

difference compared with the measured data.

0.5 T 500 470.667 441.333 0.4 412 382.667 C 324 O _ _ _ 294.667 3S 0.3 265.333 9 ~~~~~~~~~~~~~~~~236 I _ 206.667

'a llllllll177.333 0.2 148 118.667 89.3333 60 0.1 0 0.01 0.02 Radial Position m]

Figure 6. Temperature distribution in a PSBR fuel rod for steady-state of 1 MWth power (Temperature in 0C, note difference in x & y scale)

The stand-alone fuel rod code has been used to calculate the thermal response of a PSBR fuel rod during pulsing. Figures 7 through 9 represent the temperature behavior of a PSBR fuel rod after each different reactivity insertion. The stand-alone code consistently overpredicts the maximum temperature of a PSBR fuel rod. The reactivity insertions from $1.50 to $2.50 are obtained from the pulsing operations of the PSBR.

For greater precision, it is necessary to improve the gap heat transfer model, the convection heat transfer model, and the material properties of a TRIGA fuel rod. The thermal expansion model, which describes the gap heat transfer, is being further developed for a more accurate prediction of the temperature re-sponse.

102 C, r'L9

600 500 .

400 -

0P a

300 E

U-200 - - - - - - -_

100 - -

0 20 40 60 80 100 120 Time [s]

Figure 7. Fuel temperature after $1.50 pulsing 600 500 400 U

300 E

L U.

200 100 0

0 20 40 60 80 100 120 Time (s]

Figure 8. Fuel temperature after $2.00 pulsing 103

600 500

- 400 E 300 e\

- 200 - -,- - -

100~~~~~~~

100 0 - - 0

• I _ II _ _ _ _ _ _

0 20 40 60 80 100 120 Time [s]

Figure 9. Fuel temperature after $2.50 pulsing FLOWNMEASUREMENT The flow measuring experiment is the first attempt to determine the flow distribution in and around the PSBR core. From the Computational Fluid Dynamics (CFD) analysis, a flow measuring tool for the flow distribution in the PSBR pool needs a capability of measuring the velocity of 2 cm/s (less than 1inch/s) at least. Examination of the literature indicates that an extremely sensitive micro-turbine meter can measure the low velocities near the edge of the PSBR core in Figure 10. A Turbo Probe, developed by Flow Technology Inc., is proposed to be used in the PSBR pool. It has a very sensitive jewel turbine bearing for the low velocity measurement. However, the high radiation field near the core causes a problem for an electronic circuit necessary for a signal transfer. In order to prevent this problem, the electronic circuit will be located out of the pool. The calibration of the Turbo Probe is provided by the manufacturer using an accurate piston-movement method, which is combined with the electronic circuit, Linear Link, and gives linear analog signals according to flow velocities or flow rates.

Since the expected flow distribution in the PSBR pool is quite complicated, it is necessary to perform two identical experiments: with and without operation of the N- 16 pump. For thermal-hydraulic clarity, lower power operation of the reactor without the N- 16 pump will provide the flow distribution with the buoyancy-induced pattern only.

104

Figure 10. Flow measurement with the Turbo Probe assembly (unit: inches)

CONCLUSIONS The proposed research, which includes developing the CFD model, developing the stand-alone fuel rod model, and performing the flow measuring experiment, is intended to predict and explain the thermal-hydraulic behavior or the PSBR core and pool. The CFD results provide the estimation of flow distribution in the PSBR pool. Based on the CFD results, the flow measuring experiment will be performed using a very sensitive micro-turbine meter. The complex interaction between the buoyancy-driven flow and the N-16 pump jet flow will be determined by two different experiments, which will include full power, steady-state reactor operation with the N- 16 pump and lower power, steady-state operation without the N- 16 pump.

105

NEUTRON RADIOGRAPHY MEASUREMENTS FOR WATER TRANSPORT IN AN OPERATING POLYMER ELECTROLYTE FUEL CELL

Participants:

M. Mench, Prof.

J. Brenizer, Prof.

K. Unli, Prof.

N. Pekula, Grad Student K. Heller, Grad Student S. Cetiner, Grad Student Services Provided: Neutron Beam Laboratory Sponsor: General Motors Corporation, RSEC INTRODUCTION Recently fuel cell technology has become of high interest for stationary and portable power supplies including automotive applications especially. The recent attention given to fuel cells has been stimulated by vast improvements in performance, increased environmental concern, as well as a need for petroleum-free power sources. The fuel cell type receiving the most interest of late is the polymer electrolyte fuel cell (PEFC) because of its high performance, mild operating conditions, simplicity, and rapid advances since the early 1990's. For these reasons, the PEFC has been chosen, among other uses, as the most suitable replacement for the internal-combustion engine for automotive power applications.

Although, there have been numerous mathematical models in literature that predict water production and transport phenomenon in fuel cells, there has been little success in its experimental investigation.

Due to the metal housing of the fuel cell along with several of its components, neutron imaging is an attractive non-intrusive testing technique for the visualization and quantification of liquid water-reactant gas, two-phase flow within the cell. These processes yield great insight into the operation of the fuel cell pertaining to water management that can undoubtedly lead to improvements in cell performance and design.

BACKGROUND To maintain high operating performance, the fuel cell's electrolyte must be hydrated during operation to support ionic conductivity. It is common to use humidified reactant gas flows to supply the cell with appropriate amounts of water. In addition, due to the electrochemical reactions inherent to the PEFC, water is produced at the cathode of the fuel cell. However, excessive levels of water in the cell lead to a reduction in cell performance due to the obstruction of reactant gas transport. This phenomenon is referred to as "flooding", and commonly occurs in the gas reactant flow channels of the 106

cell. In addition, several water transport mechanisms exist within the PEFC, which add to the complexity of water management during operation. Therefore, there is extensive research currently ongoing industry-wide to better understand water management issues in PEFCs to improve the overall performance of the fuel cell and its design.

The membrane-electrode assembly (MEA) consists of the fuel cell's electrolyte, electrochemical reaction sites, and the gas diffusion layers (GDLs). The GDLs supply the reactant gases from the adjacent flow channels to the reaction sites. It is within this assembly and the gas flow channels that all the cell's water production and transport occurs. However, this portion of the cell is surrounded by several components comprised of aluminum and graphite including flow field plates, backing plates and current collectors (see Figure 1). Therefore, visualization of water transport within PEFCs has been extremely limited, especially that in which typical cell operation and performance has been maintained. The significant differences in neutron attenuation characteristics of hydrogenous materials and aluminum or carbon however allow for neutron imaging techniques to produce a non-intrusive visualization procedure of the two-phase flow (liquid water and reactant gas) within the cell. Neutron radiography and radioscopy in the through-plane direction of the cell, with respect to the cell's backing plates, yield adequate spatial resolution for discerning liquid water in the flow channels of the fuel cell. In addition, radiographic image analysis at the Penn State Breazealle Nuclear Reactor's (PSBR) Neutron Beam Laboratory allows for the mass and volume of liquid water within an operating fuel cell to be quantified.

Backing Plates Current Collectors Gas Flow Inlets Neutron Beam Direction Flow Field Plates with MEA located in between 107

FUEL CELL TEST SET-UP An integrated fuel cell testing station at the PSU Neutron Beam Laboratory was constructed in order to control and monitor the operating parameters a PEFC while neutron imaging was conducted. The user-friendly Neutron Beam Laboratory Test Station (NBLTS) was designed and installed so that it was isolated from the neutron beam source, protecting the operator and station components from radiation poisoning and contamination. The station can accommodate various sized hydrogen-gas fuelled PEFCs for neutron imaging processes while the following conditions are controlled by the operator on the station's control panel. Figure 2 illustrates the NBLTS layout.

• Gas flow rates

• Inlet gas temperature and humidity

• Cell temperature

• Current/Voltage draw

• Operating pressure

• Nitrogen purge NRBeam Contrete Wan Beam Carvher CAnrn Cli nks Ellesed NR Beam Cave as es "' Condeaer Una Test Stada GasExiisI Beam Catch 1If~~~~~~~~..

Gas Exits PEWC E.smlted to Atmsphere Figure 2: NBLTS Layout FUEL CELL DESIGN OPTIMIZED FOR NEUTRON IMAGING A 50cm2 PEFC is used for evaluation with the NBLTS. Aluminum flow field plates replaced more commonly used graphite plates due to lower material neutron attenuation characteristics. The aluminum plates were thinly coated with gold to increase their electrical conductivity (pictured in Figure 3) to maintain high cell performance. The thickness of the each plate was reduced to 0.25 in.

to reduce neutron attenuation and scattering. The thickness of the aluminum backing plates was also reduced from a total thickness of 2 in. to 1.3125 in. In addition, the typical copper current collectors were switched with aluminum replacements.

108

Figure 3: Gold-coated Aluminum Flow Field Plates NEUTRON RADIOGRAPHY FOR FUEL CELL APPLICATIONS The high spatial resolution associated with neutron radiography allows for excellent visualization of liquid accumulation in the PEFCs. Figure 4 below illustrates a radiographic exposure of the operating fuel cell at the specified operating conditions. The exposure time of the radiograph was approximately 4 minutes at a reactor power level of 800kW.

Operation Conditions of the Fuel Cell:

Current Density: 0.5 A/cm2 Cathode Stoichiometry (flow): 2 Anode Stoichiometry (flow): 3 Cathode/Anode Pressure: 25 psig Reactor Power Level: 800 kW Exposure Time: Approx. 4 minutes Figure 4: Radiographic Image of Operating PEFC The accumulation of liquid water in the flow channels of both the anode and cathode is visible. It is typical for an abundance of liquid water to accumulate at the 180° turns of the flow channels due to changes in flow pressure and momentum. The geometry of the channels at these locations may also aid in the accumulation of liquid water. By momentarily increasing the hydrogen gas flow rate, it was concluded that a significant amount of the total visible water in the cell was located in the flow channels of the anode.

109

NEUTRON RADIOSCOPY FOR FUEL CELL APPLICATIONS To achieve a maximum neutron beam flux, the reactor is operated at 1 MW power for all fuel cell radioscopy experiments. The spatial resolution pertaining to the applied magnitude level is approximately 225 microns per pixel. Figure 5 illustrates two-phase flow within the flow channels of the fuel cell, where he darker shaded areas depict liquid water. The temperature of the fuel cell for this example was approximately 30'C where liquid water condensation in the cell is quite abundant.

PUELCEU.emPuIN PENN TAlEUNERSflY. NUCLEARREAC1M REAZEALE Cia ALK 3.141 CAINtMW 4L1 Figure 5: Radioscopic Image of Two-phase flow in an operating PEFC The digital sampling rate of 15 frames per second for radioscopy experiments proves sufficient for all transient processes of the fuel cell including determining the velocity of moving water droplets. In addition, the accumulation and purging cycles of water inside the cell is easily attainable through real-time radioscopy.

Initial results have seen a direct correlation between the time scales of these cycles and the cell's operating conditions, most notably gas flow rates.

The ability to store individual radioscopic images digitally allows for easy post-process image analysis including ascertaining pixel intensity values within the fuel cell vensus real time. Consequently, the determination of water volume within the cell as a function of time is attainable by referencing a pre-generated calibration curve. This curve is generated using a "water-filled wedge" constructed of aluminum and other materials similar to the fuel cell. It has the exact same through-plane dimensions to duplicate the neutron attenuation and scattering effect of the fuel cell. Seen in Figure 6, the wedge contains a water filled void of known varying thickness. The steady and gradual increase in pixel shade from the bottom to top of the wedge is representative of the increasing water thickness level within the wedge. Through radioscopy of the wedge, pixel intensity values are recorded at known water thickness levels producing a calibration curve. This curve can then be referenced to assign water thickness values to individual areas within the cell or the entire cell as a whole. A calibration curve must be generated for each experiment to account for inconsistencies in the neutron beam flux and reactor power level.

110

• C,~t

_____ _ _ ,aInC~*. _ _

F44 Tools Hl r eal

• ~~~~~~~~~~~~~~~~~~~~a, n, 400ia Wi Tl~* Prme-Figure 6: Water-filled Calibration Wedge Figure 6 also illustrates the user-friendly interface that was created for fuel cell radioscopy experiments.

The length of testing and sampling rate is easily programmable.

Several post-process image enhancement techniques were established to increase the overall radioscopic image quality and accuracy of the water quantification process. Minor fluctuations in the reactor power level which is common during testing result in changes in pixel intensity values.

This causes an error by giving the allusion of varying water levels. By monitoring a reference location on each image, the fluctuation of the beam is determined and the entire pixel matrix of the image is normalized accordingly. The reference is a static location such as the backing plate outside the active area where pixel intensity should be constant throughout the length of the test. In addition, the intensity of the neutron beam is not perfectly uniform across the image resulting in different values of pixel intensity even where material attenuation characteristics and thickness are identical.

This also leads to errors in water quantification. By examining a blank image (only the uninterrupted beam) the average pixel intensity value is determined. The acquired average value is divided by each pixel value of the blank image to produce a corresponding correction factor for each pixel. The correction factor matrix is multiplied by each image recorded during actual experiments to produce a "flattened" image making the initial beam intensity uniform. Lastly, random noise and noise caused by the analog to digital conversion process can cause time varying error. The pixel intensity values of each image along with the next three frames are averaged together. This process improves image quality and makes liquid water accumulation and movement more discernible.

111

ONGOING WORK Currently, there are efforts to ensure the accuracy of the water-filled wedge calibration curve by comparing the results generated by the curve to a known water thickness. Data collection is also presently being performed for a wide range of fuel cell operating conditions. The cell's total water volume content versus time is of high interest as well as water volume at individual locations within the cell. Initial results have shown distinct time scales for the accumulation and purging periods of liquid water during fuel cell operation. Continued analysis includes investigating the relationship between these periods and various operating parameters. Liquid water droplet characteristics are also being examined including the velocity of droplets in the gas flow channels. In addition, the critical volume of the droplet in which movement initiates is measured as well as its effect on other stationary droplets. The reactant gas flow pressures, operating temperatures, and cell performance are measured and monitored in real time for each experiment.

CONCLUSIONS Neutron imaging has proven a successful non-intrusive process to visualize two-phase flow inside a polymer electrolyte fuel cell. The spatial resolution provided at the Penn State Nuclear Reactor Neutron Beam Laboratory yields excellent imaging of liquid water inside the gas flow channels of the fuel cell. Neutron radioscopy with a temporal resolution of 15 frames per second, is capable of visualizing and quantifying all the transient processes associated with operation. Preliminary results have shown quantification of water volume and water transport is attainable through these processes.

Continued research will aid in better understanding of water management issues in PEFCs and ultimately lead to improved performance and cell design.

112

CONTINUOUS FRANE CAPTURE AND ANALYSIS SOFTWARE PROJECT AT RADIATION SCIENCE AND ENGINEERING CENTER

Participants:

S. M. 4etiner, Graduate Student Jared Hoover, Undergraduate Student J. S. Brenizer, Prof.

K. Unli, Prof Services Provided: Neutron Beam Laboratory Sponsor: RSEC, DOE- Innovations in Nuclear Infrastructure and Education (INIE)

INTRODUCTION The primary goal of this project is design of software that can capture and store neutron radiography images at a rate close to real-time. The main advantage of the software is that it brings digital recording capability. Once stored digitally, images can be accessed for post-processing or for future analyses.

The application and the user interfaces are written in Java. Java is a computer programming language that fully supports portability among different operating system platforms. This allows the execution of applications across different computers and operating systems without even recompiling the source code. The only thing that the software requires is that the Java interpreter be installed. Java compiler and Java Virtual Machine can be downloaded free of charge "'. A normal user should select from under the JRE column, which stands from Java Runtime Environment. This option will install the Java interpreter and Java Virtual Machine (JVM). More advanced users might be interested in installing SDK, Software Development Kit, which also installs a standalone IDE (IntegratedDevice Environment) for Java from Sun.

The core functions of the software are based on the ImageJ [2] Java libraries. The library functions that are made available by NIH (National Institute of Health) include drivers that can communicate with the frame grabber hardware, methods that can open, save almost all image formats commonly known, and methods that can perform essential image processing.

113

KEY FEATURES OF THE PENN STATE FRAME GRABBER (PSFG) SOFTWARE The main objective of the software is to save the captured images on a block device in an organized way. During a 30-min image recording at the maximum available sampling rate, one collects more than 30 thousand images each around 300 kB, which amounts to a disk space of about 10 GB if collected at 8-bit and saved in TIFF format. In order to access any particular image out of that many images, we implemented a unique way to store the data. Following sections will elaborate on this, but it suffices to say for now that this feature is one of the most outstanding capabilities that the software has to offer that incredibly facilitates data handling.

Another important feature of the software is that it saves the references that are linked to each frame, i.e., file location and the system clock at which image is captured. This allows the user to locate each image even after the image collection is completed. Another important advantage of this is that these references are used during post-processing, mainly while images are converted into a QuickTime movie.

The software also comes with movie conversion tools. This utility program creates a digital movie file from the image collection from a plenty of video formats without altering original images. For portability and availability purposes, we chose Apple QuickTime player as the media player application to run videos.

At present, the software is defaulted to capture and record images in only 8-bit format.

THE HARDWARE Because The Penn State Frame Grabber software is written in Java, it is possible to run the application on any platform. However, the reader might be interested in getting a sense of performance related to the specifics of the hardware.

The image collection application runs on a Macintosh G4. Here are the specifics of the computer:

• Apple Macintosh G4, Dual 1.43 GHz processor,

• 2 GB physical memory (RAM),

• 600 GB storage capability,

• 256 MB AGP video card,

• Scion LG-3 card is installed as the frame grabber hardware.

The computer was a leading edge product as of last year to assure the highest performance for the application. We think that the reduced sampling rate of the application for image collection, 22 frames per second is the highest rate we could attain, is an artifact of the Java programming language.

In Java, applications are not executed directly by the operating system kernel. Instead, each Java process is interpreted and handled by a standalone kernel called Java Virtual Machine (JVM). The presence of JVM brings a lot of simplicity as far as the portability of the code is concerned at the cost of deterioration in execution performance.

One should expect a performance degradation should the application be run on a slower computer.

114

If further performance is needed, then the code needs to be rewritten in a lower level programming language, like C++ or Object-Oriented C++. Only after then may one get a better performance.

THE SOFTNVARE

1. Main Window Application The main user interface is shown in Figure 1 during a recording process. This interface is the parent application of all the applications and can execute all the children from within.

The interface allows for inputting real run time of the recording application. The user may also choose to run the application without a time limit by selecting the Run Continuously checkbox. In the continuous run mode, the user should be aware that the density of data collected is substantial, and depending on the hard disk storage capacity, the application might run into a disk overflow runtime error, which will prematurely terminate the application and might as well result in an operating system crash.

The application will save images on the hard disk by default. However, one might want to run the application solely to observe the media without storing any image. So if the Save to HDD option is disabled the application will not save captured images on the hard disk.

Vjiin*Mdlj .i -i'iu m_ =jJj/ -1iJ Fb Tools e ReaThe Vdeo TiesCon*kt -

r{ * -1 1 ~~~~~~~~30dl Secmrd ieqs Grd SdU*

s'*  : f ',~~~~~~~~~~~~~~~~~~~~~~e

-f sta*C1 rtoHDORo SWAe l~~~ _ _hpGb EI

.~~~~~~~~~~~~~~~~~~~~~~~~~~~~e Th pube i Figure 1. Main window that interfaces frame grabbing and movie conversion applications.

115

Another option, which some users might find quite useful, is the Real Time Stack option. This option will enable image storage in the physical memory, RAM, at a cost of being limited by the physical memory. One should expect the highest sampling performance should this option be enabled and hard disk storage be disabled. As a mean for comparison, for our system given in the hardware section, we usually get a sampling rate of 14-18 frames/sec by enabling the hard disk storage and disabling the real time stacking. Disabling the hard disk storage and enabling the real time stacking would bring the sampling rate up to 18-22 frames/sec, which might be critical for fast dynamics. The user should also be aware here that physical memory is generally more restricted in capacity than hard disk; therefore the application should be run for shorter periods. Otherwise, should the application overrun the amount of memory that it is allowed to allocate maximally, the application will be terminated prematurely, and in some cases and/or systems, the environment might end up in a system crash'.

Real Time Process option allows for image processing on-the-fly. There are several options for image processing, and the user can conveniently select these from the Options menu, as shown in Figure 2. The application will perform only the selected algorithms during recording session.

The main application interface also lets the user adjust the sampling rate. Because there is no a prioriknowledge on maximum available sampling rate, this selection has no upper limit. However, one should anticipate that the recording performance will be primarily limited by the runtime environment. If the user wants to reduce the sampling rate further, which in some cases might be important, this option allows to do that.

Diredor Orit s I Ca0nM hto 0 P cSi Color hversloni 0 oRedren pd OSedrnI Re 332 -mttinI Olce Q brage Fld-!`eu OFI'.bnkg _

Figure 2. Options window allows for enabling/disabling different capture and recording capabilities...

Figure 2 shows the Options window available under the Tools menu. Under Image Processingtab is presented all the accessible image enhancement/processing options.

(Footnotes)

I This is a hardware and/or operating system dependent issue.

116

2. File Organization We mentioned the difficulty of handling large quantity of images before. Our group implemented a unique technique for data organization for this project.

Figure 3 shows a file browser window. The top level directory that stores the images in a structured way is provided by the user from the Options window under Directory Options as shown in Figure 2.

Once the top level directory is provided, a directory is created in the following format:

'Company Name' - 'Project Name' 'Month' 'Day' 'Hour' 'Minute' Q - t ., D al'm F l- V

~LT.0SW ~ - -,~L . . .

Ld, Bad~ swb n A+/-drs A - Fuel"4 -Fuel Ce Octb09 044W924 _ __ _ l fi Go Fod __ X sD GM- FuelCd @

e 17 09 25 WI t GM-Fue Cd Ocber O9 03 25

~i GM-Fud Cd a-tobw 09 004 04 ii Q, 04 s1 La 05 Frame4295.tff Frame4291bff Frame4297.off

,i 2 06 i iQ 07 3 L 09 i ; 00 o 01 Fb 02 A 04 FrMe 4296.tff Frare 4299.tff Fryw 4300.tff 5i as hi la 0 2 07 09 D

Fb11 EM GO 12 Frame430Lbff Fra., 4302bf FraMe 4303.tff Wi 14 tois 016 p617 N 19

a. 20 Fr&e4304.bff FrMe 430.5ff Frame4306.bff W.~ 21 I .22

. 023 024 FM 25 W 027 021 Frate 4307.tff 0020 13obc_ 3.81 M chLoW ienftw Figure 3. Directory structure in which captured frames are stored... Please note that the time stamp that is showed in big red dashed oval on the video in Figure 7: The above directory structure is created based on the information from the system clock, and the same time stamp is printed to the top of each frame in video along with the associated frame number.

117

As an example, the directory name as shown with 1 dashed red oval in Figure 3 can be examined as follows:

GM - Fuel Cell October 09 04 04 Company Project Month Day Hour Minute Name Name Having created the main directory for a particular experiment, the application continues to create new directories under this for each minute that follows. The 2nd red dashed oval in Figure 3 is an example.

Under each minute directory that is created, new directories are created for each second to come, as shown with the 3 rd oval in Figure 3. Images that belong to that time interval, i.e. the minute and the second, are recorded on the hard disk under the associated directory. Because the same operation is performed continuously, each image goes to the correct location, which makes file tracking very straightforward.

During the image recording, the application also saves the references to file location and capture time for each image to related files. Figure 4 shows the details from the file location and recorded time for Frame 4304, which is the same frame marked as 4 in Figure 3. These references will be used by Movie Builder, as will be discussed in the next section.

. - Fuel Cell October 09 e 04 04/09/24/Frame 4303.tiff il - Fuel Cell October 09 04 04/09124/Frre 4304.tiff A - Fuel Cell October 09 04 4/09/24/Frae 4305.tiff 1

'I7 O Csi --ler Oc 04 04O09 4 FrRoe-,z Frame 4i- 2003, October 09 Thu 04:09:24:654 rye 4304 2003, October 09 Thu 8 04:09:24:7B rrane 4305 2003, October 09 Thu 04:09:24:787 Figure 4. Each image is recorded with its directory location and time stamp.

3. Movie Builder Still images have only very little to say about the dynamics of the system being observed. The motion of a system can only be captured in a movie format. Movie Builder acts as an intermediary tool for conversion from a collection of images to a particular movie. Figure 5 shows the user interface for Movie Builder.

Movie Builder is designed both as a standalone utility application and as an embedded tool in the main application: The user can execute the code by selecting Tools > CreateMovie > Create Movie from Filesmenu item.

118

F Tools Help Figure 5. Movie Builder utility to convert collected an image collection to a QuickTime movie...

The interface is fairly simple to use. Before commencing the conversion process, Movie Builder expects the user to enter the top level directory where the image collection is stored. For a legitimate entry, the user is supposed to provide a directory withfileList.txt, timeStamp.txt, and codecSettings.txt files. Otherwise, the conversion process is not commenced and the user is given a warning.

=_ - ~-_I~4~

~~lMPEG4Vsdeo B~~~~~~~~~~MPGvd J__ __ _ ____ __ - I -~@

H Bee s DVACPRO -NTSC

_ DVCPRO-PAL Grirs H.261 H.263 InW IlrdeW dw 4.4 window (left)... MotionJrG A I enMcdr eJoE Phido G Ram#~ p16B Elum RGS R Bon~~~~~~~~~~~~~~~~~~~~~~~~~Il.AFF Figure 6. Compression settings dialog window (left). .. Motion frame rate is automatically retrieved by the application from the execution log for each run. Users can choose from a multitude of video encoders (right). The default encoder is set to MPEG-4 Video for its superior features.

119

If the user inputs a valid directory, the user is then asked to choose the movie compression parameters as displayed in Figure 6. First the compression encoder is to be chosen from a dropdown menu.

Then, depending on the specifics of the movie encoder, other parameters are chosen.

Quality is usually a common motion picture conversion parameter, which determines the resolution of the video, and therefore the file size. Generally a medium quality works pretty well. For example, with MPEG-4 Video format at medium quality, one gets an astounding compression ratio of about 1/

50 with a reasonably fine resolution.

Having set the compression parameters, Movie Builder starts to create the video from the image collection scanning from the first through to the last directory in the list. During the conversion process, reference information is also attached to the movie, as demonstrated with a video sample recorded for General Motors Fuel Cell Project in Figure 7. The white band at the top with information for each frame in the video is called the header. The header is optional and is added to help the user keep track of frames easily. The information includes the company and project name, as indicated with the blue oval, and other important references. The user will be able to locate a particular frame down the stack by looking at the time information. As an example, the 15' and the 2nd red ovals in Figure 7 give hints regarding the whereabouts of Frame 4304. In fact, Figure 3 illustrates how to track down a particular frame in an image collection, Frame 4304 in this case.

'0QT1eis Od 9 Close-Up.mov _ X E E ENEiFUet vrxh W W46 GENEPA^LIOTORSI Frame 4304 2003. October 09 Thu 04:09:24:71 t

'~ ?" ane

.. --..ss ~ vr IK

... Il£ eeraC7A 11^ ^

-T^- CLn Figure 7. Video can be played by QuickTime Media Player. One advantage of QuickTime is that it can be freely downloaded for almost all operating systems.

120

The conversion process is rather time consuming. As an example, the conversion of 10 thousand images takes about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to complete on a 2.8 GHz-Pentium 4-processor PC; much longer than the image collection time. Part of the reason is that the conversion algorithm requires further reduction of hard disk access time with improved memory allocation, and additional code optimization. Another reason for this delay is that header addendum is a CPU demanding process.

After the conversion is finished, Movie Builder notifies the user that the process is complete; otherwise it will give an error message. The user will find the QuickTime movie file in the top level directory that was chosen when Movie Builder was first started.

4. Playback with QuickTime Media Player QuickTime is a media player application from AppleTM Computers. The base version of QuickTime can be downloaded from the product website [3] free of charge.

The movie is platform independent and can be played back on any computer and operating system provided that QuickTime application is installed and the video decoder for the movie is supported.

If the required decoder is not installed in QuickTime, the application automatically warns the user and asks to download the codec automatically.

ONGOING WORK The following capabilities are to be added in the future versions of the software:

• capturing and/or recording images in 8-bit, 12-bit, and 24-bit format (this requires hardware support) a new utility program, FrameExplorer, that allows forbrowsing and seeking back and forth in a directory structure that keeps the image collection,

• better movie conversion performance DOWNLOAD INFORMATION The software can be downloaded at http://nesrin.rsec.psu.edulPSUFrameGrabber/

ACKNOWLEDGEMENT We would like to thank developers at the NIH and contributors of the ImageJ software, particularly Wayne Rasband for his help to the development of the software.

REFERENCES

1. Download Java 2 SDK, v 1.4.2_02 (J2SE), http://java.sun.com/j2se/1.4.2/download.html

2. ImageJ Software, National Institute of Health, http://rsb.info.nih.gov/ij/

3. Apple - QuickTime - Download web page: http://www.apple.com/quicktime/download/

121

STUDY OF A LOOP HEAT PIPE USING NEUTRON RADIOGRAPHY

Participants:

J. S. Brenizer, Prof.

J. M. Cimbala, Prof.

Po-Ya A. Chuang, Graduate Student Services Provided: Neutron Beam Laboratory Sponsor: Bechtel Bettis, Inc., Bettis Atomic Power Laboratory INTRODUCTION Thermal management is always a challenging and interesting topic in various applications, like permafrost stabilization, electronic equipment cooling, aerospace, etc. How to effectively remove heat from the heat source or supply heat to the heat sink has became a major obstacle for many newly developed technologies. Heat pipes have been the solution to a lot of engineering problems for the past several decades. A heat pipe is a two-phase heat transfer device used to transport heat in a highly efficient and effective manner. The effective coefficient of thermal conductivity of a heat pipe can be orders of magnitude higher than that of highly conductive solid materials, such as copper.

The heat transfer device investigated in this entire study is called a Loop Heat Pipe (LHP). It is a particular kind of heat pipe in which the evaporator and condenser components are separated, with the working fluid transported between the two components via tubing or pipes. After successfully demonstrating the heat transport capability and reliability in space applications, LHPs started gaining worldwide attention in the 1990s. LHPs are proven to be robust, self-starting and passive thermal transfer devices under regular operating conditions. Currently, LHPs have been used mainly in the spacecraft industry. With more and more ground test data, engineers who design terrestrial applications may find themselves interested in the development of LHPs.

A LHP consists of five key components: an evaporator, a reservoir, a condenser, a liquid line, and a vapor line. Surface tension developed in a porous material is the source of the pumping force used to circulate the fluid. A schematic diagram of a typical LHP is shown in Fig. 1.

When heat is applied to the evaporator body, it is conducted radially into the primary wick. Due to capillary action and surface tension, the liquid at the outer surface of the primary wick is vaporized and collected in the vapor channel. The amount of liquid vaporized depends on how much heat is applied to the evaporator. Because the vapor in the vapor channel has the highest pressure in the system, it flows through the vapor line to the condenser. In the condenser, where the heat is rejected, the vapor is condensed back to liquid and slightly subcooled. The liquid then flows through the 122

liquid line back to the evaporator. In the evaporator/reservoir assembly, the liquid line is referred to as the bayonet, which directs the liquid all the way to the closed end of the evaporator. After the liquid exits the bayonet into the evaporator core, most of the liquid wets the primary wick and the secondary wick. The excess liquid goes back to the reservoir through the non-wick flow path. This completes the flow cycle in aLHP.

Fig. 1: Schematic diagram of a loop heat pipe.

Loop heat pipes are very attractive heat transfer devices that have great potential in various applications. Although many papers regarding LHPs have been published, most of them present test results and discussions on certain specific aspects of LHP operation. Some aspects of LHP behavior are still not fully understood. Thus, a complete detailed operating theory of LHPs has not yet been developed and needs to be studied further.

Neutron imaging is an ideal flow visualization tool for LHP study if the working fluid contains hydrogen (high neutron attenuation), and the shell of the LHP is made of aluminum or stainless steel, which is nearly transparent to thermal neutrons. Liquids and vapors can also be easily distinguished since a liquid attenuates neutrons much more than a vapor of the same substance, because of the large density difference. Thus, the neutron beam laboratory in the Radiation Science and Engineering Center was utilized to see-through the test LHP for detailed study.

123

EXPERIMENTAL SETUP A schematic diagram of the setup in the Neutron Beam Laboratory (experimental room) and control room is shown in Fig. 2. During neuron radiography tests, the test loop was placed in the radiation active experimental room, while the chiller, Variac, data acquisition system, computer, monitor, and video recorder were placed in the control room. For safety, the experimental room has thick concrete walls to shield operational personnel and equipment from neutrons.

Control Room Cooling Water Flow Line -- -- -> Image Transport Line .-

=F Power Control Line -v Data Transport Line Fig. 2: A schematic diagram of the experimental setup in the control room and experimental room of the Neutron Beam Laboratory. (Not to scale) 124 C-1

DISCUSSION OF RESULTS Neutron radioscopy can be used to monitor the loop while it is operating. Dynamic and transient phenomena can be identified by neutron radioscopy. Radioscopic images were recorded on high-resolution videotape. Real-time difference images were used to qualitatively study the change in ammonia distribution.

One neutron radioscopic image of the reservoir is shown in Fig. 3. This image shows the details inside the reservoir, including the liquid level in the reservoir and the details of the bayonet. The aluminum and stainless steel portions of the LHP are essentially transparent to the neutrons. The ammonia and cooling water are sufficiently attenuating to produce good contrast, even in two-phase Fig. 3: Neutron radioscopic image of the reservoir and the evaporator.

From the results obtained with neutron radiography and radioscopy, operating characteristics like reverse flow in the liquid line or two-phase flow in the vapor line were observed; these are discussed as follows.

Reverse Flow:

The flow of the working fluid in the liquid line is sometimes opposite to the normal flow direction, as observed with neutron radiography. This is a transient phenomenon, observed only when there's a sudden drop of applied heat load, e.g., when the heater is turned off. With less heat load, the liquid-vapor interface moves toward the inlet of the condenser, which draws back liquid downstream of the interface from the evaporator core. This interface self-adjusting phenomenon causes reverse flow in the loop.

125

Two-Phase Flow in the Liquid Line:

Under certain operating conditions, the liquid line may be filled with vapor or two-phase fluid rather than liquid. These conditions include when the sink temperature is higher than the ambient temperature, and at transient operating conditions (after adjustment of the heater power or the sink temperature).

These observations agree with the predicted results of the steady-state model.

Two-phase flow in the vapor line (gravity-assisted operating theory):

To validate the proposed operating theory at positive elevation, neutron radiography was used to examine the LHP vapor line. Images were taken at different heat loads with a positive elevation of 4" inches (102 mm). The images from neutron radioscopy are difficult to interpret without knowing the physical setup of the LHP in front of the neutron camera, therefore a picture of the setup is shown in Fig. 4.

N4eutron Camera Insulated reservoir Vapor line Liquid Line Fig. 4: A picture of the LHP setup in front of the neutron camera.

Fig. 5 shows images from neutron radioscopy taken at steady- state conditions when the heat load is equal to 5,25,70, 150, and 300 watts, respectively. These images give qualitative information of what happens in the vapor line. When the heat load isis equal to 5 W, liquid chunks in the vapor line can be easily observed, and the flow pattern is slug flow (Fig. 5a). As the power is increased to 25 W, liquid slugs could still be observed in the vapor line (Fig. Sb). However, the slug at 25 W is lighter than that at 5 W, indicating less liquid. From the neutron radioscopy, it is observed that the slug travels at a higher speed with the heat load equal to 25 W than with the heat load equal to 5 W.

126

As the heat load is further increased from 25 to 70 W (Fig. Sc), the flow pattern changes from slug flow to stratified flow. Instead of liquid slugs, a thin liquid film at the bottom of the tube is consistently observed.

When the heat load is further increased to 150 W, this liquid film at the bottom can still be observed (Fig.

5d), although it is thinner than that in Fig. Sc). As the power is further increased to 300 W (Fig. 5e), the liquid disappears completely and the vapor line is filled with 100% vapor. In this test, the LHP operates in the gravity-controlled mode when the heat load is equal to or less than 150 W, and in the capillary-controlled mode when the heat load is equal to or greater than 300 W. The transition heat load fell somewhere between 150 and 300 W.

a) d) b) e) c)

Fig. 5: Images from neutron radioscopy when the heat load is equal to a) 5 W, b) 25 W, c) 70 W, d) 150 W, and e) 300 W at 4-inch positive elevation.

127

CONCLUSION This study presents a theoretical and experimental study of loop heat pipes (LHPs). The most significant result of this study is the discovery, development, and modeling of the operating theory at gravity-assisted conditions. The operating characteristics when the LHP is operating in the gravity-controlled mode are unique and have never been studied before, neither experimentally nor analytically.

In this study, with the aid of neutron radiography, the gravity-assisted operating theory is explained thoroughly and the performance of a LHP can be predicted analytically.

In this study, neutron radiography was proven to be a useful visualization tool to study the operating characteristics of a LHP. It would be an ideal tool to study specific problems like temperature oscillation, which can be identified in the transportation line or in the condenser. However, due to the construction of the evaporator, neutron radiography was unable to see-through the evaporator.

The operating conditions in the evaporator core were unable to be identified, which is the key factor for several important issues, like temperature hysteresis and low-power start-up. To see through the evaporator core using neutron radiography, special design of the evaporator is required, including the geometry, thickness, length, and material. With proper design, neutron radiography has great potential for visualizing what is happening in the evaporator core.

Despite the complexities and uncertainties, LHPs offer a potential solution to the next generation's thermal management problems. LHPs are the most reliable two-phase heat transfer devices, and have very high thermal conductivity. Within 10 years, LHPs may become the most popular device in the thermal management industry, both in space and ground applications.

Doctoral Thesis:

Author: Chuang, P-Y.A., J.M. Cimbala (Advisor), and J.S. Brenizer (Co-Advisor)

Title:

An Improved Steady-State Model of Loop Heat Pipes Based on Experimental and Theoretical Analyses Publications:

Chuang, P-YA., J.M. Cimbala, and J.S. Brenizer, et al. "Comparison of Experiments and 1-D Steady-State Model of a Loop Heat Pipe," InternationalMechanicalEngineeringCongressandExposition, New Orleans, LA, November 17-22, 2002 128

DEVELOPMENT OF A SINGLE-DISK NEUTRON CHOPPER FOR T]IEE-OF FLIGHT SPECTROSCOPY AT PENN STATE

Participants:

J. Neiderhaus, Grad Student J. Brenizer, Prof.

K. Unlu, Prof.

Services Provided: Neutron Beam Laboratory Sponsor: DOE, Innovations in Nuclear Infrastructure and Education (INIE)

INTRODUCTION A single-disk, "slow" chopper system' 2 has been developed at the Penn State Radiation Science and Engineering Center (RSEC) for the purpose of energy spectrum measurements on thermal neutron beams.

This was achieved by gating the beam with a single rotating narrowly-slotted disk of neutron-absorbing material (a "chopper") and measuring the resultant time-of-flight (TOF) distribution of transmitted neutrons to an adjacent detector, located at a known separation distance. The TOF distribution was transformed to distributions in neutron speed and energy, which closely matched models based on the Maxwell-Boltzmann distribution. The advantage of this technique is that no measurement of the neutron or secondary particle energy deposition is necessary.

EXPERIMENTAL SETUP AND DAKTA ACQUISITION Instead of measuring energy deposition, the TOF system recorded neutron counts and arrival times at the detector, relative to a known starting time. This starting time was established at the instant when the 1-mm-wide radial slit in the chopper disk reached full illumination as it passed through the beam. This occurred once per rotation, emitting a 384-ms-long pulse of neutrons in a thermal spread, which then traversed a known distance to the detector. The chopper disk rotated with a period of 115 ms, and was covered on both faces with 1-mm thick Cd sheet overlaid with Gd paint.

Neutrons transmitted by the chopper slit traversed a 2.1 8-m collimated flight path and interacted in a shielded LiI(Eu) scintillatorby (nt) reactions. A photomultiplier tube/multi-channel scaler (MCS) system counted these events in 1024 20-ps-wide data channels, sweeping over all of the channels sequentially once per chopper rotation. The start of each sweep was synchronized to the opening of the chopper slit using a photodiode triggering device on the chopper apparatus.

The chopper slit was centered in the RSEC primary neutron beam, at the exit of a 19.1-cm-diameter, 3.4-m-long beam tube (Figure 1-5). Neutrons were generated in the RSEC TRIGA Mark III reactor core, and moderated by a large D 2 0-filled tank coupled directly to the core. The beam tube used for this study had a direct view of the D 2 0 tank. The beam diameter was reduced to 3.8 cm, and then to 1.9 cm, by two 36-cm-long cylindrical Pb/concrete collimator plugs, placed at the downstream end of the beam tube.

129

With the reactor operating at a power of I MWt, the neutron signature from the chopper was nearly undetectable due to the gamma field, unless appropriate measures of collimation were used. Two sets of 5-inch deep Pb bricks, closely spaced to match the width of the beam transmitted by the chopper, were inserted in a straight tube between the chopper and detector for this purpose. The background due to gammas still present in the beam was further reduced by pulse-height discrimination.

Figure 1. Schematic layout of Breazeale reactor core, beam port #4 and neutron chopper time-of flight system.

2m detector neutron beam

/ collimator tube Pb chopper Figure 2. Schematic of chopper, collimator tube, and detector 130 C-1$

1mm slit Al Neutron beam -

cross section Disk rotation Neutron pulse duration:

384 gs.5 cm 0.36 Non-reflective mark7_

Side view optica I trigger med ianism Figure 3. Schematic of single-disk neutron chopper Figure 4. A picture of single disk neutron chopper 131

Figure 5. A picture of chopper and collimator tube at beam port #4.

DATA TRANSFORMATION The experimentally-measured data consisted of 1024 channels, each containing a number of accumulated counts, recorded over 150,000 MCS sweeps. A series of mathematical operations, performed on a channel-by-channel basis, was used to transform this dataset to distributions of differential flux in the time (TOF), velocity, and energy domains. The domain variables assigned to each channel were calculated as D

ti = (i - 1). dt, V=i , and E= mvi 2 where t.is the flight time, i is the channel index, dtis the MCS dwell time per channel (20 ps), D is the flight distance, and m is the neutron mass.

After background subtraction, the recording time per channel, dwell time, and detector efficiency were used to convert the recorded counts in each channel to the differential flux per unit time-of-flight (d#dt)1.

Two chain rule factors were then applied to convert this value to differential flux per unit speed (do'dv)1 ,

and differential flux per unit energy (doldE),. In this way, the total recorded flux was conserved.

132

MODELING AND RESULTS The neutron beam is fully thermalized in the D 2 0 moderator material. Hence, the differential number density of neutrons in the moderator with velocity v in dv can be described by the Maxwell-Boltzmann formula. Since flux is related to number density by = n - v , the flux of neutrons with velocity vin dv is described by the Maxwell-Boltzmann formula, modified by a factor of vand appropriately renormalized:

do(v) fm 2V3 exp -MV 2A) dv 21kT ) ( 2kT where is the total flux, k is Boltzmann's constant, and Tis the moderator temperature (20'C). Similarly, the Maxwell-Boltzmann distribution in energy is modified by a factor of En1 to describe the flux distribution:

dE kT )

IK ( kT These two distributions constitute a Maxwell-Boltzmann-based model to which experimental results from the chopper can be compared.

Figs. 6 and 7 show the velocity and energy spectra derived from experimental data, along with the corresponding Maxwell-Boltzmann-based models. The "measured" data points are (d4Ydv), and (dW' dE)1 , corrected for background, detection system dead time, and losses in air along the flight path. One data point per MCS channel is plotted, located at the velocity (v;) and energy (Es) corresponding to the midpoint ofthe time channel. The "moder' data points are the Maxwell-Boltzmann-based formulae evaluated at v; and E., after correction for losses in air in the beam tube.

133

9000 8000 7000

'A 6000 Ir -ModeLl Kc 5000

~~~~~~~~~~~~

>eI 4000 I 0 3000 2000 1000

______ . . . . __ 0 L.. .. .. . . ... .. I...

0 0 2000 4000 6000 8000 10000 12000 Velocity (m/s)

Figure 6. Thermal neutron velocity spectrum 3.5E+08 3.OE+08 2.5E+08 2.OE+08 0~

a>

1.5E+08 I .OE+08 5.OE+07 O.OE+O0 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Energy (eV)

Figure 7. Thermal neutron energy spectrum 134 (Ci

CONCLUSIONS The spectra generated by the chopper are in good agreement with physical models. These spectra fit the models to within one standard deviation. Since a slow-chopper spectrometer of this type is relatively simple and inexpensive to construct, it is hoped that future work will further develop this instrument for use in precise spectroscopic measurements on thermal neutron beams.

REFERENCES

1. T. Emoto, Ph.D. thesis, Cornell University, Ithaca, NY (1990).

2. S. Spern, Ph.D. thesis, Cornell University, Ithaca, NY (1998).

Thesis:

Niederhaus, John Henry J. "A single-disk-chopper time-of flight spectrometer for thermalneutron beams."

A Master of Science Thesis in Nuclear Engineering, The Pennsylvania State University, August 2003.

AUTOMATED THREE-DIMIENSIONAL MONTE CARLO BASED DEPLETION METHODOLOGY FOR PSBR CORE

Participants:

C. Tippayakul, Student K. Ivanov, Associatet Professor Sponsor: Radiation Science & Engineering Center The research is focusing on the application of Monte Carlo method to the Pennsylvania State University Breazeale Reactor (PSBR) core calculation. The Monte Carlo code, MCNP, is employed to model the PSBR core. The depletion calculation capability for the PSBR is made possible by coupling the MCNP code with the depletion code, ORIGEN2.2. These two codes are interfaced with a new developed computer code, TRIGSIM. The new development of the TRIGSIM code includes automatic generation of MCNP and ORIGEN input from a TRIGSIM input. Cells, surfaces and material compositions in the MCNP input are determined from TRIGSIM input describing fuel rod positions and dimensions, control rod elevations, and fuel rod compositions. After the MCNP input was generated and calculated, the TRIGSIM code extracts the fission reaction rate of each fuel rod and generates ORIGEN input for each fuel rod based on the extracted fission rate. When ORIGEN completed all fuel rod burnup calculations, the TRIGSIM code updated the material changes to the next burnup step until the calculations are complete.

Each of PSBR core loadings is being modeled using the automated TRIGSIM code starting from core loading 1 up to the current core loading. The PSBR core loading 1, core loading 2, core loading 3 and core loading 4 were calculated. The calculation results were compared to the measured data from the operation log book. Table I shows the eigenvalue comparison between the calculated values and the measured value.

135

Moreover, new temperature dependent cross section libraries for the TRIGA reactor are generated from ENDF/B-VI data file. The temperature dependent cross section is being used for MCNP code to more accurately perform core calculation. The use of temperature dependent cross section reflects more realistic feedback from temperature to the core calculation. The cross section library generation processes for U-234, U-235, U-236, U-238, H- , Zr-Natural, thermal scattering of Zr in ZrH and thermal scattering of H in ZrH were completed and were validated.

Future tasks include the development of the PSBR core model up to current core loading, the implementation of the temperature dependent core section to the automated 3D Monte Carlo based depletion code TRIGSIM and the development of acceleration scheme for Monte Carlo calculation. In addition, the coupled Monte Carlo/Nodal method methodology will be performed to efficiently provide the spatial distribution of the PSBR core. The integration of all methodologies into one computer code package will be the final step of the research. The computer code system will be available for the future PSBR fuel management and core analysis.

DRAG REDUCTION IN TURBULENT FLOWS: DIRECT OBSERVATION OF VERY RAPID FLUCTUATIONS IN POLYMER-SOLVENT INTERACTIONS

Participants:

G.L. Catchen, Professor C.C. Dey, Postdoctoral Research Associate J. deJong, Graduate Student Services Provided: Angular Correlations Laboratory, Laboratory Space Sponsor: American Chemical Society, Petroleum Research Fund, Grant No. 36322-AC9,

$40,000 Low concentrations of linear polymers can greatly reduce drag in various types of fluid transport. Although scientists have identified many drag-reducing polymers, investigators have not been able to observe directly the polymer-solvent interactions causing drag reduction. For this purpose, we use perturbed-angular-correlation (PAC) spectroscopy. This technique is based on tagging a very small fraction of polymers with radioactive probe ions, 'In or '8'Hf. which act as "rotational tracers" and are used to measure nano-scale relaxation times associated with polymer motion. Specifically, using PAC spectroscopy, we measure hyperfine interactions between these probe nuclei and the extra-nuclear, chemical environment. In principle, we can measure rapid fluctuations in these hyperfine interactions that motion of the polymer causes. Thus, we could characterize the polymer motion via these measurements. Concomitantly, we could identify changes in polymer conformation caused by shear during flow. Executing the project involves four major tasks: (1) develop techniques to bind the PAC probe ions to several different polymers, (2) identify and analyze the hyperfine interactions, which are observed on polymers dissolved in static solutions, (3) design apparatus with which to make PAC measurements on flowing solutions, and (4) analyze hyperfine interactions measured in solutions of polymers that are flowing under drag-reducing conditions.

136

During the first two years of the project, we have experienced considerable difficulties binding the probe ions to the polymers and identifying the corresponding hyperfine interactions. As far as we know, no PAC experiments of this type have been reported. Measurement of a series of perturbation functions for the electrolytic polymer, poly-acrylic-acid, dissolved in solutions of ethylene glycol and water show that the parameter X2, which is proportional to the nano-scale relaxation time, increase with increasing viscosity produced by ethylene glycol.

Masters Thesis:

deJong, Jeremy, "Study of polymer motion in fluids using perturbed angular correlation spectroscopy,"

M.S. Thesis, Mechanical Engineering, Pennsylvania State University. Research Supervisor, Dr. Gary L.

Catchen (In progress)

NEUTRON RADIOGRAPHY FOR TWO-PHASE FLOW VISUALIZATION IN POLYMER ELECTROLYTE FUEL CELLS

Participants:

M. Mench, Assistant Professor of ME J. Brenizer, Professor-in-Charge of Planning and Admin./Program Chair of Nuc.E K. UnlW, Professor of Nuclear Engineering N.Pekula, M.S. Student Services Provided: Neutron Radiography Sponsor: General Motors, $75,000 We are using the NR facilities to image and quantify the water distribution in an operating polymer electrolyte fuel cell. This issue (liquid water accumulation and transport) is a major technical challenge in the fuel cell industry.

Publications:

Several Project updates delivered to General Motors Personnel. Technical publication in preparation.

NEW CORE LOADING

Participants:

N. Kriangchaiporn, Graduate Student K. Ivanov, Assistant Professor Sponsor Radiation Science & Engineering Center The PSBR core loading cycle 51 has been activated since December, 1999. Currently, the reactor is operating with $4.62 excess reactivity. This value, due to bumup, is lowe than desired for the TRIGA reactor. Consequently, the plan to transform the core to the new loading was established. The objective of this study is to seek for the new core pattern that reaches the desired excess reactivity of $6.40. The 3-D 137

nodal diffusion code ADMARC-H has been used to perform the core simulation using two-group cross section generated by HELIOS, 2-D lattice physics code. The results from ADMARC-H are in good agreement with the experimental results for the current core loading cycle 51 A within - 1.95% of the excess reactivity. The new core configuration has been predicted and will be implemented afterward.

PARALLEL MODEL BASED ON 3-D CROSS SECTION GENERATION FOR TRIGA CORE ANALYSIS

Participants:

N. Kriangchaipom, Graduate Student K. Ivanov, Assistant Professor Sponsor: Radiation Science & Engineering Center Transport theory provides the basic physics method for analyzing a nuclear reactor core. Although, up to now, the three-dimensional (3-D) transport methods have been considered to be computationally expensive for practical analysis of LWR cores, the much smaller dimensions of the TRIGA core and the current progress in computer technology allow such methods to be applied and validated. The research is focused on the development of an efficient 3-D transport model for TRIGA core analysis based on the Sn method.

The Sn transport theory method is one of the most accurate numerical approximations for solving the linear Boltzmann equation. The first part of this study deals with the development of multi-group cross-section generation methodology for such model has been done. Different steps of the methodology are presented on the 8.5 wt% TRIGA fuel cell using the DORT code. We have developed a homogenized 18-group cross-section library for simulation of a TRIGA core. The results indicate very good agreement with 279-group library and reference MCNP results. This homogenized 18-group cross-section library will be used further for the TRIGA core analysis.

PSBR Scholarship Research Projects NEUTRON RADIATION RESISTANCE OF SiC: EXPERIMENTAL DEMONSTRATION

Participants:

A.T. Motta, Associate Professor G.L. Catchen, Professor C. Tyree, Graduate Student C. Trivelpiece, Undergraduate Student F. Ruddy, WEC A. Dullo, WEC J. Seidel, WEC Services Provided: Neutron Irradiation, Laboratory Space, Angular Correlations Laboratory Sponsor: FERMI Industrial Consortium 138

Cory Trivelpiece and Chris Tyree are conducting research on silicone carbide wafers that are being consider for radiation detection equipment. The semiconductor material is very resilient at high temperatures and could be used inside the pressure vessel of commercial reactors. The research project's main focus is on what kinds of defects are caused by neutron irradiation and at what temperature will the sample anneal and return to a defect free state. Irradiation of the samples is conducted at the Breazeale facility along with the analysis and annealing of the samples. Analysis of the samples is conducted by using Positron Annihilation Spectroscopy. The research is funded by the FERMI group and is done in conjunction with Westinghouse Electric Company.

NEUTRON IRRADIATED SILICON CARBIDE STUDIED USING POSITRON ANNIHILATION LIFETIME SPECTROSCOPY Participant: Cory Trivelpiece, Undergraduate Nuclear Engineering Sponsor: Radiation Science & Engineering Center In the Spring 2003, much was accomplished regarding the FERMI project. The goal of this project is to characterize the type or types of radiation induced damage in silicon carbide wafers, which have been exposed to varying neutron fluences. These wafers were irradiated at the PSBR, both in the central thimble and at the reactor core face. No new irradiations were performed during the 2003 spring semester.

However, the samples that were irradiated at earlier times were isochronally annealed to temperatures of 800'C. The samples are annealed in an effort to impart enough thermal energy into the SiC lattice so the irradiation-induced defects become mobile. When this happens, the defects will migrate throughout the lattice until these defects annihilate with each other or get absorbed at defect sinks. The average positron lifetime is higher in wafers containing radiation damage. Because of the higher lifetime in irradiated wafers, the positron lifetime should decrease as the defects are eliminated. It is thought that the thermal energy needed for this defect mobility to occur is associated with temperatures exceeding 1400'C. Therefore, no change in the positron lifetime has been noticed. Future work will include the irradiation of new wafer pairs to different fluences, as well as the annealing of these wafers combined with the subsequent positron lifetime measurements.

Plant Pathology Department. Fusarium Research Center

Participants:

J.Juba, Research Support Technologist Carnation leaves are irradiated in the Cobalt-60 facility in order to provide a sterile growing medium for Fusarium species at the Fusarium Research facility. Nearly every project in our lab relies on the use of these leaves and as far as I know we are the only source of irradiated carnation leaves worldwide. We make them available to others in the Fusarium research community, charging fees to cover our costs. You might find some helpful information at http://frc.cas.psu.edu/.

139

Publications:

Moorman, GW, S. Kang, D.M. Geiser, and S-H. Kim. Identification and characterization of Pythium species associated with greenhouse floral crops in Pennsylvania, Plant Disease 86: 1227-1231,2003.

Taylor, J.W., J. W. Spatafora, K.L. O'Donnell, F. Lutzoni., T.Y James, D.S. Hibbett, D.M. Geiser, T.D. Bruns, and M. Blackwell. The Fung,. I The Tree of Life, Cracraft, J. and Donoghue, M, eds. In Press, 2003.

Geiser, D.M. Practical molecular taxonomy of fungi. Advances in Fungal Biotechnology for Industry.

Agriculture and Medicine. Plenum Publishers, In Press, 2003.

Chaverri, P., L.A. Castlebury, G..J. Samuels, and D.M. Geiser. Multilocus phylogenetic structure within the Trichodermaharzianum/Hypocrealixii complex, Mol. Phyl. Evol, 27: 302-313,2003.

Kang, S., J.E. Ayers, E.D. DeWolf, D.M.Geiser, G.A. Kuldau, G.W. Moorman, E. Mullins, J.C. Correll, G. Deckert, Y-H Lee, Y-M Lee, F.N. Martin, and K. Subbarao. The Internet based Fungal Pathogen Database: A Proposed Model, Phytopathology, 92: 232-236,2002.

Shen, Q., D.M. Geiser, and D.J. Royse. Molecular phylogenetic analysis of Grifolafrondosa(maitake) reveals a species partition separating North American and Asian isolates, Mycologia, 94:472-482,2002.

Nalim, F.A., G..J. Samuels, R.L. Wijesundera, and D.M Geiser. Biogeography of the Fusarium solani species complex: sampling in the Southern Hemisphere, The Mycological Society of America, Asilomar, California, July 2003.

Jiminez-Gasco, Maria and D.M Geiser. Killing Fusarium moniliforme: correct identification of Fusarium Research Center culture collection accessions using molecular phylogenetics, The Mycological Society of America, Asilomar, California, July 2003.

Jiminez-Gasco, M.M., M.G. MIlgroom, and R. M. Jimenez-Diaz . Stepwise evolution of Fusarium oxysporum f. sp. ciceris races inferred from fingerprinting with repetitive DNA sequences, American Phytopathologival Society, Charlotte, North Carolina, August 2003.

Presentation:

Ning Zhang, D.M. Geiser, and K. O'Donnell. A Molecular Phylogenetic Study of the Fusariumsolani Species Complex Mycological Society of America 2003 Annual Meeting at Asilomar, California.

140

The Energy Institute and Department of Energy and Geo-Environmental Engineering DEVELOPMENT OF HIGH TEMPERATURE H/02 PROTON EXCHANGE MEMBRANE FUEL CELLS

Participants:

S.N. Lvov, Associate Professor H.R. Allcock, Professor C.M. Ambler, Ph.D. Candidate R.M. Wood, Ph.D. Candidate E.Chalkova, Research Associate A.E. Maher, Ph.D. Candidate M.Pague, Graduate Student D.K. Jayabalan, Graduate Student Service Provided: Gamma Irradiation Sponsor: Department of Energy, $75,000/year The goal of the project is to develop a high temperature polymer electrolyte fuel cell.

This work is an interdisciplinary effort involving researchers and students from Dr. Lvov and Dr Allcock research labs. The principal aspects of this work are (1) polymer design, synthesis, and membrane properties optimization; (2) membrane characterization and fabrication of membrane electrode assemblies; (3) construction of a bench-scale prototype fuel cell and determination of MEAs performance at elevated temperatures. We utilize the radiation facility to cross-link our polymeric materials. The process of cross-linking produces mechanically strong membranes, and reduces membranes water uptake.

Ph.D. Theses:

Maher, A. E., and Allcock H. R. advisor, in progress, Ph.D.

Ambler, C. M., and Allcock H.R., advisor, in progress, Ph.D.

Wood, R. M., and Allcock H.R., advisor in progress, Ph.D.

Michael Pague, and Lvov S.N., advisor in progress, Master's Publications:

Hofmann, M.A., C.M. Ambler, A.E. Maher, E. Chalkova, X.Y Zhou, S.N. Lvov, and H.R. Allcock.

Synthesis of Polyphosphazenes with Sulfonimide Side Groups, Macromolecules 35,6490,2002.

Zhou, X.Y, J. Weston, E. Chalkova, M.A. Hofmann, C.M. Ambler, H. Allcock, and S. Lvov, High Temperature Transport Properties of Polyphosphazene Membranes for Direct Methanol Fuel Cells, Electrochim, Acta 48,14-16,2173-2180,2003.

E. Chalkova, X.Y. Zhou, C.M. Ambler, M.A. Hofmann, J.A. Weston, H.R. Allcock, and S.N. Lvov.

Electroch Solid State Letters, 5, 10, A221, 2002.

141

Allcock, H.R., M. A. Hofmann, C.M. Ambler, S.N. Lvov, X.Y Zhou, E. Chalkova, and J. Weston, Phenyl Phosphonic Acid Functionalized Poly[aryloxyphosphazenes] as Proton-Conducting Membranes for Direct Methanol Fuel Cells, J. of Membrane Science, 201,47-54,2002.

Ambler, C.M., A. E. Maher, R. M. Wood, H. R. Allcock, E. Chalkova, S. N. Lvov. Novel Polyphosphazenes for Use in Fuel Cell Applications, PMSE preprints- Accepted May 2003.

Veterinary Science Department

Participants:

M.Sylte, Post-doctoral Student L.Sordillo, Professor Services Provided: Gamma Irradiation Sponsor: National Institute of Health RO1 HL6044 - $1,500,000 over 5 years awarded to Lorraine Sordillo THE ROLE OF 15-LIPOXYGENASE IN THE PATHOGENESIS OF ARTHEROSCLEROSIS.

We tested out ability to perform RNA interference (RNAi) experiments, a novel technology to "knock-down" gene transcription. We utilized a previously developed plasmid expressing RNAi against p 53 ,

which is a cytoprotective protein known to be induced in response to ionizing radiation. The hypothesis tested whether knocking-down p53 mRNA expression would block its induction after treatment with ionizing radiation. We transfected Human Embryonic Kidney 293 (HEK-293) epithelial cells with or without a combination of plasmids containing p53 RNAi, naked vector and a p53-luciferase reporter, and subjected them to gamma irradiation. As expected, RNAi successfully blocked the activation p53 in HEK-293 in response to ionizing radiation, and was a success. With these data, we felt confident that RNAi experiments could be performed. Because the interest of this laboratory is 15-lipoxygenase activity in endothelial cells, it is unlikely that we will be using ionizing radiation over the next year. Future experiments will be directed at developing RNAi for 15-lipoxygenase in bovine endothelial cells. These experiments were preliminary data for a NIH RO 1 renewal proposal.

142

Northeast Technology Corporation

Participants:

D.Vonada K.Lindquist Services Provided: Neutron Irradiation, X-Ray Radiography, Laboratory Space Neutron absorber materials such as BORAL, Boraflex, borated stainless steel and several new boron carbide/aluminum metal matrix composites are used for criticality control in spent nuclear fuel storage racks and in dry spent fuel storage and shipping casks. The work at RSEC includes qualification of new materials such as BorTec and METAMIC for these applications as well as testing surveillance coupons of these neutron absorber materials for in-service performance verification. A key attribute which is tested is the neutron absorber capacity. This work is conducted in the Beam Hole Laboratory at RSEC.

Other attributes tested include dimensional stability, mechanical properties, elevated temperature performance and corrosion resistance. This work is ongoing.

143

SECTION B. OTHER UNIVERSITIES, ORGANIZATIONS AND COMPANIES UTILIZING THE FACILITIES OF THE PENN STATE RADIATION SCIENCE & ENGINEERING CENTER

___~~~~~~~~MN,1 AAR Neutron Transmission Bettis Labs, Westinghouse Neutron Radiography Bio-Pore, Inc. Gamma Irradiation COGEMA (formerly Transnucleaire France) Neutron Radiography Neutron Radioscopy Neutron Transmission Cornell University Neutron Radioscopy Eagle-Picher Neutron Radiography Neutron Radioscopy Neutron Transmission Fairchild Corporation Semiconductor Irradiation General Motors Neutron Radiography Neutron Radioscopy Hamilton-Sundstrand Neutron Radiography Lockheed Martin Semiconductor Irradiation NETCO (Northeast Technology Corporation) Neutron Radioscopy Neutron Transmission NWT Isotope Production Oglevee Ltd. Gamma Irradiation Qualtity Services Laboratory Plus Irradiation of Electronic Devices Raytheon, St. Petersburg, FL Irradiaiton of Electronic Devices Raytheon Company, Sudbury, MA Irradiation of Electronic Devices Raytheon Systems Company, El Sequndo, CA Irradiation of Electronic Devices St. Louis Metallizing Company Neutron Transmission Synetix Isotope Production TRW Irradiation of Electronic Devices Tru-Tec Isotope Production University of Georgia Neutron Activation Analysis University of Pittsburgh, Greensburg Neutron Activation Analysis Westinghouse Science & Technology Center Neutron Irradiation 144

- 12 i ads~~k~ - ' - * #

-* -H

• f - pendices

,4p

.I

, " Y II

APPENDIXA Personnel Utilizing the Facilities of the Penn State RSEC.

Faculty (F), Staff(S), Graduate Student (G), Undergraduate (U), Visiting Professor (VP), Visiting Scholar (VS), Faculty Emeritus (FE), Post-Doctoral (PD), High School Student (HS)

I WOIo 6=7MI am IN II[%Iw M11F.411(11111 Irudeau. J. F Daubenspeck, Thierry S Kizil, Ramazan lG Davison, Candace S Decker, Chanda U Juba, Jean lS deJong, Jeremy G Dey, Chandi PD Sordillo, L. ;F Edwards, Bob F Sylte, M. G Flinchbaugh, Terry S Grieb, Mark S Hahn, Dianna G Hauck, Danielle G He, Weidong G Heidrich, Brenden F Hochreiter, Larry F Chalkova, Elena Huang, Zhengyu G Jayabalan, D.K. G Ivanov, Kostadin F Lvov, SN. F Kenney, Edward FE Maher, A.E. G Klevans, Edward FE Pague, M. G Kohlhepp, Kaydee U Wood, RM. G Koziol, Adam U Kriangchaiporn, Natekool G Liszewski, Rob U Marcy, Melisa U Burgos, William F McCullough, Randy S Dempsey, Brian F Mench, Matt F Morlang, G. Michael G

_~~~~~ Motta, Arthur F ang, Andrew G Niederhaus, John G han, eP. F Pekula, Nick G Portanova, Alison S Admns, Jaclyn U Rankin, Paul S Aim, Fatih Cane, eny G Rickert, Bret U AmYousry F Sarikaya, Baris G Brenizer, Jack- F Schaeffer, Tristan U Bryan, Mac S Sears, C. Frederick F Catchen, Gary F Slaybaugh, Rachel U Cetiner, Sacit G Taylor, Bryce G Chance, Henry G Tippayakul, Chanatip G Chang, Jong G Todorova, Nadejda G Chaung, Abel G Trivelpiece, Cory G 145

YIUV1 1r Lavr Whisker. Vaughn G Wilks, Ben Ts Yilmaz, Serkan lG Bondar, Greg G Hirth, K F Bollinger, .J., Jr.F KrbCarsten F Price, J.C. G Saleh, L. G Fetchko, M. G Hanna-Rose, Wendy F Lai, Z.C. F Sharna, R. S Sun, H. G Bertocchi, Dave S Boeldt, Eric S Hermann, Greg S Linsley, Mark S Morlang, Suzanne S 146

AAR Phil Pusilio Bettis Labs, Westinghouse Tom Conroy Bio-Pore, Inc. Steve Schwartz COGEMA (formerly Transnucleaire France) Guillaume Bostetter Renaud DeVera Jacques Gardine Cornell University Mark Dinert Eagle-Picher Monte Hart Jerry Houdyshell Sandi Rushin Fairchild Corporation Joe Macieunas General Motors Tom Trabold Hamilton-Sundstrand Kevin Hartman Peter Kinsman Joe Montefusco Ken Zacharias Lockheed Martin Alex Bogorad Surinder Seehra NETCO (Northeast Technology Corporation) Matt Harris Ken Lindquist Doug Vonada NWT Jerre Palino Oglevee Ltd. Ed Mikkelson Qualtity Services Laboratory Plus Michael Lange Raytheon, St. Petersburg, FL Craig Uber Raytheon Company, Sudbury, MA Bruce Black Raytheon Systems Company, El Sequndo, CA Ed Craig St. Louis Metallizing Company Klaus Dobler Synetix Scott Vidrine TRW Frank Cornell Don Randall Tru-Tec Mike Flenniken Jerre Kolek University of Georgia Rebecca Downey University of Pittsburgh, Greensburg Hollie Ramaley Tim Savisky Ted Zaleskiewicz Westinghouse Science & Technology Center Abdul Dulloo Frank Ruddy John Seidel 147

APPENDIXB Formal Tour Groups

.I~li I "ii Xi.. jf Pfo0 M0 3.-r meT Personal 07/02/02 I ANL 08/07/02 1 Former Student and Guests 07/02/02 3 PSU Student 08/12/02 5 VIEW 07/03/02 19 Personal 08/19/02 1 Personal 07/08/02 1 NETCO 08/21/02 1 Physics Students 07/08/02 11 Personal 08/23/02 1 Physics and Chemistry Teachers 07/09/02 8 ARL 08/27/02 1 Governor's School 07/10/02 34 Freshman Seminar 08/27/02 19 TRTR 07/11/02 3 Freshman Seminar 08/29/02 18 Governor's School 07/11/02 34 Personal 08/30/02 2 Personal 07/17/02 1 Daily Collegian 09/04/02 1 NST 07/17/02 6 Personal 09/06/02 1 Personal 07/18/02 3 Prospective Student 09/06/02 4 Spend a Summer Day 07/22/02 6 CPI 09/12/02 12 Engineering Union Steward 07/23/02 1 Cornell University 09/12/02 2 Physics and Chemistry Teachers 07/24/02 14 IE 408 W Meeting 09/13/02 2 Brazil 07/24/02 1 OPP 09/16/02 5 Prospective Student and Family 07/24/02 2 NucE 401 09/18/02 9 00 Environmental Camp 07/25/02 31 EASI House 09/24/02 27 Personal 07/25/02 1 NucE 301 09/25/02 Personal 07/26/02 1 Student 09/25/02 Reactor Sharing 07/26/02 7 Student 09/26/02 Spend a Summer Day 07/26/02 4 Student 09/26/02 1 Spend a Summer Day 07/26/02 8 State College, The Magazine 09/27/02 13 1

Personal 07/28/02 1 VWR 10/01/02 28 5

Framatome 07/29/02 2 Charter School 10/01/02 23 23 INEEL 07/29/02 3 Biology Dept 10/01/02 Spend a Summer Day 07/29/02 9 Student 10/02/02 2

International Grad Students 07/30/02 3 STS 150 10/03/02 1

NucE Grad Student 07/30/02 1 Westinghouse 10/03/02 15 Personal 07/31/02 5 Work Study Student 10/04/02 1 Bettis 08/02/02 2 Student-ME 30 10/04/02 15 Spend a Summer Day 08/02/02 9 Parent's Weekend Open House 10/05/02 283 Spend a Summer Day 08/02/02 2 ABET 10/07/02 I Oglevee 08/07/02 1 Student 10/08/02 I

APPENDIXB Fonnal Tour Groups

. . nn I. - ~ v -rT9 I .u. -=.: rO;.

University Pitt-Greensburg 10/08/02 2 RPO Retiree 11/08/02 I Food Science 10/08/02 Prospective Students 11/08/02 7 Radiation Protection Conference, 10/08/02 19 Personal 11/15/02 1 Personal 10/09/02 1 NucE Faculty/Student 11/15/02 2 Food Science 10/10/02 26 Department Speaker 11/21/02 2 Personal 10/10/02 2 Eagle-Picher 11/21/02 2 Personal 10/10/02 1 Oakridge National Lab 11/22/02 2 FBI 10/11/02 1 Personal 11/22/02 2 Personal 10/11/02 2 NucE Grad Student 11/25/02 2 LHP Tour 10/14/02 1 Framatome 11/25/02 1 Student 10/15/02 1 Personal 11/27/02 2 Personal 10/15/02 I Personal 11/29/02 I NucE 401 10/16/02 8 Personal 11/29/02 5 Air Force NDT 10/16/02 1 Personal 11/29/02 4 Cornell University 10/22/02 2 Prospective Student and Family 12/02/02 3 IE 408 W 10/23/02 20 Personal 12/03/02 2 IE408W 10/24/02 16 INIE 12/09/02 11 ORNL 10/24/02 1 ESAC 433H 12/11/02 12 IE 408 W 10/24/02 26 Conway Trucking 12/12/02 I Schreyer Honors & Nativity HS 10/25/02 17 CEDEC 12/12/02 2 AG 150 10/28/02 23 Student 12/12/02 1 Houserville Elementary 10/29/02 53 PSU Student 12/13/02 1 PPL/INPO 10/29/02 2 Berwick High School 12/16/02 9 Interview 10/30/02 1 Personal 12/16/02 1 Halloween Party 10/31/02 5 Home School Group 12/17/02 7 Personal 10/31/02 Cornell University 12/17/02 2 Personal 10/31/02 12 University Pitt-Greensburg 12/18/02 3 Student 10/31/02 1 Computer Science & Engineering 12/18/02 3 PSU Alumni 11/01/02 2 Personal 12/19/02 2 Prospective Student and Family 11/04/02 2 Christmas Party Guests 1219/02 17 College of Engineering 11/05/02 Vet Science 12/19/02 I Houserville Elementary 11/05/02 Police Training 12/19/02 7 Associated Press 11/06/02 2 DOJ-FBI 12/20/02 1 Personal 11/06/02 1 PSU Students 12/20/02 2

APPENDIXB Formal Tour Groups

. . .. - 9CM.7-rizz Me.

Biochemistry 01/02/03 I Personal 03/14/03 7 Ag & Bio Engineering 01/03/03 I Personal 03/16/03 1 Police Training 01/03/03 11 Prospective Student 03/17/03 1 Personal 01/08/03 I National Instruments 03/17/03 1 Biochemistry 01/08/03 2 Personal 03/17/03 I FilTech 01/09/03 1 BWX Technologies 03/19/03 I DEP 01/10/03 1 NRC 03/20/03 I NucE 444 01/13/03 8 Il-VI Inc. 03/21/03 NucE 450 01/15/03 1 Girl Scouts 03/22/03 26 Freshman Seminar 01/16/03 18 Personal 03/22/03 1 Nittany Office 01/24/03 1 PAJSHS 03/24/03 12 Brockway High School 01/28/03 8 Tyrone Middle School 03/25/03 29 Police Services 01/28/03 19 Tyrone Middle School-Bus Drivers 03/25/03 2 FilTech 01/29/03 1 Tyrone Middle School 03/25/03 30 NucE Faculty 02/05/03 1 Anthropology 03/27/03 1

_ Graduate Students 02/07/03 4 PPL 03/27/03 1 o Boy Scouts 02/08/03 54 Greensburg Salem HS 03/28/03 23 Mechanical and Nuclear Engineering 02/12/03 1 Physics Department 03/31/03 2 Police Services 02/12/03 1 ME 30H 03/31/03 20 PSY 432 02/12/03 18 Student 03/31/03 1 ELCO 02/13/03 9 Grove City College 04/01/03 15 Personal 02/18/03 I CE 597D 04/01/03 8 Student 02/20/03 I Students 04/01/03 2 Seminar Speaker 02/20/03 I Altoona Chemistry Class 04/01/03 10 Boy Scouts 02/22/03 32 Department Speaker 04/02/03 I Personal 02/22/03 1 BCMB 04/03/03 1 Personal 02/22/03 I Personal 04/03/03 1 Canberra 02/24/03 I Student 04/09/03 1 Personal 02/25/03 1 IE 408 W 04/09/03 26 DEP 02/27/03 I 1E408W 04/10/03 24 Biology 02/28/03 1 Security Bid Meeting 04/10/03 6 Personal 02/28/03 2 1E 408 W 04/10/03 23 Engineering Open House 03/01/03 139 Hollidaysburg High School 04/11/03 41 Personal 03/03/03 I Department Speaker 04/14/03 1

APPENDIXB Formal Tour Groups 0e MUM _ S S - I. -1~1 Outstanding Engineering Alumni 04/14/03 1 Engineering Services 05/14/03 3 Williamson High School 04/15/03 19 Grier School 05/15/03 12 PSI 04/15/03 1 Nittany Valley Charter School 05/16/03 29 Mechanical and Nuclear Engineering 04/16/03 1 Personal 05/16/03 10 PSI 04/16/03 1 Prospective Student and Family 05/19/03 3 CEDCC 04/16/03 1 Personal 05/20/03 1 Personal 04/17/03 2 Cornell University 05/20/03 1 Punxsutawney High School 04/17/03 17 ADA 05/21/03 4 Brownies 04/17/03 27 St. Mary's High School 05/23/03 27 DOE 04/18/03 1 Personal 05/23/03 1 Personal 04/18/03 2 Selinsgrove High School 05/27/03 15 Personal 04/21/03 1 Physics Department 05127/03 1 BMB 04/22/03 2 Personal 05/27/03 2 Personal 04/24/03 1 EMS 05/28/03 3 Take Your Daughters & Sons to Work 04/24/03 9 Kane High School 05/28/03 14 Take Your Daughters & Sons to Work 04/24/03 13 Vet Science 05/28/03 2 Police Training 04/24/03 6 Personal 05/28/03 2 Personal 04/24/03 2 COE HR 05/29/03 1 Spring Grove High School 04/25/03 19 FilTech 06/02/03 1 Graduate Student 04/25/03 1 Mechanical and Nuclear Engineering 06/02/03 2 ME Faculty 04/25/03 1 SP McCarland Co. 06/03/03 2 Former Student 04/25/03 1 Personal 06/03/03 2 Cornell University 04/27/03 1 Personal 06/09/03 1 Personal 04/28/03 1 AAR Cargo Systems 06/11/03 2 Marion Center 04/29/03 12 Job Shadow 06/11/03 1 Red Lion Christian School 04/30/03 17 Soil Sciences/PSIE 06/11/03 8 Ligonier Valley High School 05/01/03 36 Entomology Department 06/12/03 1 Department Speaker 05/01/03 1 Oak Ridge National Lab 06/18/03 2 ITS-telecommunications 05/02/03 1 VIEW 06/19/03 24 Computer Science & Engineering 05/02/03 2 Site Review Committee 06/20/03 2 95.3/3WZ 05/08(03 1 WISE Week (Group A) 06/23/03 19 Personal 05/09/03 2 Personal 06/23/03 1 DOE 05/09/03 1 State College Preview 06/23/03 2 University Pitt-Greensburg 05/14/03 4 WISE Week (Group B) 06/23/03 19

APPENDIXB Formal Tour Groups VIEW 06/26/03 14 PSU IRO 06/26/03 5 PSU Students 06/26/03 4 Scalacs 06/27/03 1 Personal 06/27103 2 Alpha Fire Company Volunteers 06/30/03 22 1562

• 183 other individuals visited the facility but did not partake in a formal tour (i.e., caterers, physical plant supervisors, human resource reps, office maintenance personnel, vendors, etc.)