ML20149J975
| ML20149J975 | |
| Person / Time | |
|---|---|
| Site: | Texas A&M University |
| Issue date: | 07/22/1997 |
| From: | TEXAS A&M UNIV., COLLEGE STATION, TX |
| To: | |
| Shared Package | |
| ML19317C540 | List: |
| References | |
| ENVR-970722, NUDOCS 9707290177 | |
| Download: ML20149J975 (9) | |
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O APPENDIX F i
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l ENVIRONMENTAL REPORT
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- OF FACILITY LICENSE R-23 O DOCKET # 50-59 AGN20lM (serial #106)
TEXAS A&M UNIVERSITY l
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i ENVIRONMENTAL REPORT 1
i CONTENTS 1.0 INTR O D U CTI ON . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I 2.0 RECENT REACTOR OPERATING HISTORY . . ... . . . ...... ................. 3 1
3.0 GASEOUS EFFLUENT: ARGON-41 PRODUCTION..... .. .. .. ......... ..... 4 4.0 OTH E R E F FL U ENTS . . . . . .. . . . . . . . . . . . . ... . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. . 5 5.0 ENVIRONMENTAL MONITORING.... . ..... .. .... . ........... ................... 5 6.0' C O N C L U S I O N S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 d
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1.0 INTRODUCTION
The Texas University AGN-20lM has been operated by the Department of l Nuclear Engineering in the Collage of Engineering for nearly 40 years. The reactors l operating license R-23 was first issued by the United States Atomic Energy Commission
- in 1957. The AGN-201M has been operating in the reactor facility in the Zachry
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Engineering Center since 1972. The reactor is currently used both as a research device j
j and as a training center for students in the Department of Nuclear Engineering and for j facility reactor operators. The reactor is used in laboratories which are directly associated I with classes taught in the Department of Nuclear Engineering, the reactor is used to irradiate sma!! samples for later analysis in counting laboratories and for conducting for
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reactor operations for the training of students.
The reactor room is located in room 61 B of the Zachry Engineering Center. !
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- The reactor room is designed so that it can only be entered through a double set of doors that are built in a concrete block wall. This door has an electromechanical lock with
! combination and is located in a concrete block wall in the middle of what once was one l
large room.' The exterior walls and ceiling of the reactor room and room 61 A are constructed of 3.5 and 4.0 thick concrete, respectively. The reactor room,61B has the !
n following dimensions ,12 foot high walls and a floor that measures 29 feet by 25 feet.
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The AGN-201M reactor is a self-contained, thermal reactor with a compact core of <20% enriched uranium oxide homogmously dispersed in a matrix oflow-density polyethylene. The reactor core is contained in a hermetically sealed aluminum can that isolates the reactor fuel and prevents the escape of fission-product gases to the environment. Since the reactor has such a low thermal power no external means are
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2 required to cool the reactor core. Heat transfer of fission energy occurs through A
() conduction from the fuel through the graphite reflector and lead shield surrounding the core to the approximately 1000 gallons of water contained in the shield tank. In addition to serving as a fast neutron shield, the water acts as a massive thermal sink. Hence, there are no thermal or radioactive liquid effluents released from the facility.
Since 1973 this reactor has been operated with a maximum rated power level of 5 watts. All shielding surveys in the area of the reactor and in the accelerator laboratory l
above indicate extremely low radiation levels except when operating at higher power l levels. The highest radiation levels have been noted in the area around the rear skirt door, this local area has been posted as a high radiation level during 5 watt reactor
- operations and all personnel in the reactor facility are briefed on the areas of highest l
possible exposure. It should be noted that the reactor is only operated at higher power n
d- levels during required reactor maintenance procedures and not during normal reactor operations.
A radiation protection program is administered by Radiological Safety Division of Texas A&M University's Environmental Health and Safety Office. The University Radiation Safety Officer heads up the office of Radiological Safety. This office provides administrative and technical support for all users of radioactive materials at TAMU.
I All personnel assigned to the reactor facility and the Head of the Department of Nuclear l Engineering have been issued individual radiation dosimeters which measure equivalent dose from beta, gamma and neutron radiation. No visitors are allowed in the reactor facility during reactor operations and students working in the reactor facility are issued self-reading pocket dosimeters. Two environmental monitoring film badges are placed in
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3 areas inside and outside the reactor room to measure cumulative exposure to ionizing f3
() radiation. These environmental monitorss, as well as personnel dosimeter devices, are 1
analyzed on a monthly basis.
l 2.0 RECENT POWER lilSTORY i
The AGN-20lM reactor has had limited power history in the last few years. This i has been primarily due to material problems associated with the reactor channel #2 l
1 drawer. The reactor has been operated for many years in direct support of several Nuclear j i
Engineering classes and for operator proficiency. The reactor is mostly operated during j l
the start of both the fall and spring semesters. Students perform reactor startups for both graduate and undergraduate reactor laboratories and other experiments are conducted ,
1 during tliese times using the reactor facility. i A
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Table 1. Average annual values for AGN-201 reactor operations.* i Annual Operations 28.9211ours Energy Generation 10.25 watt-hours Mean Power Level 0.666 watts l
- Data from Annual Operating Reports from May 90 - May 96, May 94-May 95 not used I due to very limited reactor operations during this time period.
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'h 3.0 GASEOUS EFFLUENT: ARGON-41 PRODUCTION
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V With the design of the AGN-20lM reactor core and fuel, the production of argon-41 is considered to be the only gaseous effluent of concern. Since argon-40 is a minor constituent of dy air,0.93 percent by volume or 1.3 percent by mass, the ,
production Ar-41 should be at least considered. Argon-41 is produced by the neutron capture in argon-40. The only air volumes that might be effected are those in the glory hole or inside one of the access ports. The access ports are filled with wood , lead and graphite under normal operating conditions. Air is also contained in solution in shield tank but this tank is sealed from the ouiside environment. Other considerations are that the flux level in the shield tank is much lower than in the areas closer to the core and that .
the argon concentration in the tank will be vey small. In order to reach saturation activity at the highest possible concentration levels the air in question would have to be
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V irradiated for at least seven half-lives, about 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> at maximum rated power. The AGN-20lM reactor has not been operated at full power for this length of time in the past and such reactor operations are very unlikely in the future.
With the small amount of air actually exposed in the sealed glory hole, the low reactor power history and the large amount of airflow thought the laboratory the production levels of argon-41 and release levels are very minuscule. The reactor facility has its own discharge flow path through the accelerator laboratory and out a discharge vent on the roof of the four-story Engineering Building.
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l 4,0 OTilER EFFLUENTS i
No liquid or solid radioactive effluents are generated by the AGN-20lM reactor
- facility. The only radioactive material produced is that used in irradiation experiments l
and all this material remains within the Department of Nuclear Engineering laboratories l
j or is disposed of by Radiological Safety as solid waste. If any material were irradiated l
l for use other than in the department, Radiological Safety would have to transfer the l
material to a sub licensee. With the presence of a TRIGA reactor at the University, no outside departmental irradiation work takes place in the AGN reactor facility.
Some levels of reactor structure and component activation have been experienced during decommissioning of this type of reactor but that has been limited to components l
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[ - that have been in direct contact with the uranium-impregnated polyethylene fuel disks.
Some contaminated surfaces were also found but were limited to the inner surface of the d core, in-core graphite reflector and the interior surfaces of the aluminum clads of the safety and control rods. Since this will not be of concern until decommissioning and is already a recognized problem, measures will be taken at that time to prevent any possible spread of contamination.
l 5.0 ENVIRONMENTAL MONITORING All environmental monitoring is done by the Radiological Safety personnel. A radiation survey of the reactor facility and surround laboratories is performed an annual
! basis. These annual survey are done at the sam; ints every year and are compared to I
previous radiation surveys. With the thickness of both the ceiling and the surrounding walls of the reactor room and the accelerator room, only very low levels of radiation can
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6 be detected outside the reactor room even during full power operations. Contamination I r"'S
( ,) surveys of the reactor room and adjoining laboratory are currently performed on a monthly basis by Radiological Safety personnel.
Two environmental dosimeters are currently in place in areas in and around the
! reactor room to measure accumulated equivalent doscs. One is located in the reactor l room itself, another is in the adjoining laboratory. These dosimeters are film badges and plastic tract-etch (CR-39 or equivalent) for detection of beta, gamma and neutron l
radiation.
6.0 CONCLU$!ONS No events have os curred or maintenance items performed which might in any way l have affected the physical barriers between the reactor core and fuel and the local O
l V environment. All contamination surveys have indicated no loose surface contamination i in the reactor room and the annual radiation surveys have verified the effectiveness of the shielding at all reactor power levels. Any and all material associated with experiments performed with the AGN-201 remain within the confines of the departmental laboratories, none are transferred to other facilities. If material were to be transferred the l
personnel of Radiological Safety would make all the necessary arrangements and transfer the material, since departmental personnel are not authorized to make such transfers of material.
l The benefits of continuing operation of the TAMU AGN-201 to the current and future students in the Department of Nuclear Engineering far outweigh any minor O
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negative environmental effects. The reactor by its design considerations and ct.rrent !
- location will pose no significant environmental impact. i i
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