ML19296B587
| ML19296B587 | |
| Person / Time | |
|---|---|
| Site: | 07000157 |
| Issue date: | 08/27/1979 |
| From: | TEXAS, UNIV. OF, AUSTIN, TX |
| To: | |
| Shared Package | |
| ML19296B583 | List: |
| References | |
| 13943, NUDOCS 8002210115 | |
| Download: ML19296B587 (12) | |
Text
I' 4
APPLICATION FOR RENEWAL OF LICENSE SNM-180 SPECIAL NUCLEAR MATERIALS Submitted to Director, Division of Materials Licensing U.
S.
Nuclear Regulatory Commission Washington, D.
C.
20545 by Nuclear Reactor Laboratory University of Tevas at Austin Austin, Texas 78712 3002210
\\l5 13913
?-
1 APPLICATION FOR LICENSE FOR SPECIAL NUCLEAR MATERIALS 70.22 (a) (1)
Name of Applicant:
Nuclear Reactor Laboratory Mechanical Engineering Department The University of Texas Austin, Texas, 78712 D.
E.
Klein, Laboratory Director Address as above All officers of The University of Texas and the Nuclear Reactor Laboratory are presently citizens of the United States of America.
70.22 (a) (2)
Activity for Which Special Nuclear Material is Requested:
The Nuclear Reactor Laboratory of the University of Texas uses Special Materials to improve and facilitate its training programs in the fields of nuclear science and engineering.
The items described below in paragraph 70.22 (a) (4) are
,used for laboratory instruction in Junior, Senior, and Graduate level courses in the NucJear Engineering Program in the Department of Mechanical Engineering.
The Laboratory areas in which the material will be used are the Nuclear Reactor Laboratory of the Department of Mechanical Engineering and the Center for Nuclear Studies of the Department of Physics on the main campus of The University of Texas at Austin, Austin, Texas.
70.22 (a) (3)
Requested duration of license is for 5 years.
70.22 (a) (4)
Lescription of Special Nuclear Material:
The Special Nuclear Material to be covered by this license has been used with great effectiveness in our teaching laboratories since its arrival under Grant SNM-180 dated February 27, 1958, and later amendments.
Experience has shown us ways of
2 improving the material utilization.
This improved utilization is facilitated through access to and control of portions of the material covered by the original license and later amendments by different departments of The University or Texas; therefore only those materials which are utilized by the Nuclear Reactor Laboratory are described below for licensing.
I.
Plutonium-Beryllium Scaled Sources:
A.
Description M-798 This scarce contains 31.960 gms of Pu sealed in a tantalum and stainless steel capsule with dimensions of 1.021" O.D.
x 2.182" high.
The Pu is 93.02325% enriched in (Pu-239 + Pu-241) making a total of 29.730 gms of (Pu-239 + Pu-241).
The source has a total strength of 6
3.62 x 10 neutrons /second.
M-799 This source contains 79.940 gms Pu sealed in a tantalum and stainless steel capsule with dimensi~ons of 1.31" O.D.
x 2.72 " high.
The Pu is 93.02325% enriched in (Pu-239 + Pu-241) making a total of 74.363 gms (Pu-239 + Pu-241).
The source has a total strength of 6
8.82 x 10 neutrons /second.
M-797 This source contains 15.970 gms Pu sealed in a tantalum and stainless steel capsule with dimensions of 1.02" O.D.
x 1.46" high.
The Pu is 93.02325% enriched in (Pu-2 39 + Pu-241) making a total of 14.8560 gms (Pu-2 39 +6Pu-241).
The source has a total strength of 1.81 x 10 neutrons /second.
B.
Usage The above listed sources are used (1) for maintaining a steady neutron flux in the suberitical reactor and (2) for calibration of neutron detection instruments.
To maintain a steady f?.ux in the suberitical assembly one of the sources is placed in the center of the core with the remaining voids filled with core materials and/or reflector material.
The location of this use of the sources is in the Nuclear Reactor Laboratory.
Fig. 1 Page 3 shows the geometry of the source in the core.
3 0.010 " POLYETHYLEN E WALL DETAIL OF T
VOID FILLER (V
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CORE QR REFLECTOR MATERidL DISKS ACTIVATION
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GRAPHITE REFLECTOR O
10 "
Irii iIi iii SCALE FIGURE I
4 II.
Enriched Uranium in Subcritical Assembly:
A.
Description The subcritical core consists of eight large disks and originally of 36 smaller disks.
An inventory in 1974 discovered that three (3) of the small disks were missing and this fact reported to the U.S. Nuclear Regulatory Commission (Mr. Richard Bangart RO IV).
Subsequently, two (2) of the disks have been recovered for a total of 35 now present.
These disks are made from 00 nriched 2
to 19.77612% U-235 impregnated in high density polyethylene.
The total weight of Uranium is 2375.34 gms and the weight of Uranium-235 is 469.75 gms.
B.
Usage The subcritical assembly is used with the Plutonium-Beryllium sources in the Nuclear Reactor Laboratory.
A floor plan of the Nuclear Reactor Laboratory is shown in Fig. 2 Page 5.
- 70. 22 (a) (6) Technical Qualifications of Appli; ant:
The staff members who will be in charge of using the Special Nuclear Material and their experience are as follows:
Klein, Dale E.: Director, Nuclear Reactor Laboratory Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas.
B.S., Mechanical Engineering, University of Missouri, 1970; M.S.,
Mechanical & Aeropsace Engineering, University of Missouri, 1971; Ph.D., Nuclear Engineering, Univer-sity of Missouri, 1977.
Bauer, Thomas L.:
Associate Director, Nuclear Reactor Laboratory, Department of Mechanical Engi-neering,- The University of Texas at Austin.
B.S.,
Physics, University of Texas at Austin, 1971; M.S.
Nuclear Engineering, University of Texas at Atsuin, 1975; Ph.D., Nuclear Engineering, University of Texas at Austin, 1978.
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6 Burack, Joseph A.:
Supervisor, Nucleat-Reactor Laboratory, Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas United States Navy (Nuclear) 1964-1972; Operator-trainee Nuclear Reactor Laboratory, 1973; Nuclear Regulatory Commission Operators License, 1974; Nuclear Regulatory Commission Senior Operators License, 1975.
70.22 (a) (7) Facilities and Equipment for Handling the Special Nuclear Material.
Plutonium-Beryllium sources M-797, M-798, and M-799, when not in use, are stored in one of the three 10 inch diameter by 10 feet deep steel storage wells shown in the facility floor plan, Fig. 2 page 6.
Radiation levels at the top of the well, with all three Pu-Be sources in the well, are less than
.5 mr/hr neutron and less than.5 mr/hr beta-gamma.
Long handling tongs and long threaded rods are available for handling purposes.
Access to the sources and rooms where the sources are used is controlled by the Director and Supervisor.
The 35 small uranium disks are, when not in use, stored in the floor vault as shown in Fig. 2 page
- 5. Access to this safe is directly under the con-tol of the Supervisor.
The large disks as well as the subcritical assembly are stored and used within the confines of the Nuclear Reactor Laboratory.
The Plutonium Beryllium sources are occasionally used at the Balcones Research Center, Building 10, as calibration standards.
When used at that facility they are transported and stored in a standard 15 gal Mound neutron source shipping container.
A drawing of the shipping container with radiation levels is included in Fig. 3 page 7.
Both the Nuclear Reactor Laboratory and the Balcones Research Center, Building 10 facilities are routinely monitored by the University Radiation Safety Officer.
7 N
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FIGURE 3
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8 70.22 (a) (8)
Safety Procedures for Minimizing Danger to Life or Property:
The Plutonium-Beryllium sources are swipe tested for leakage and/or contamination semi-annually.
These swipes are then counted by the University Radiation Safety Officer.
In the event this test reveals the presence of 0.005 microcurie or more of removable contamination, the source will be removed from service, decontaminated, or returned to manufacturer.
All positive leak tests will be
=
reported immediately to the U. S. Atomic Energy Commission.
Manipulation of the sources is supervised.by Reactor Laboratory staff personnel.
All rooms where the sources are used or stored are
" restricted areas".
These rooms are locked with keys possessed only by qualified Reactor Laboratory personnel.
These areas are routinely monitored by the University Radiation Safety Officer.
The subcritical assembly is located in the same areas with the same controls as the Plutonium-
~
Beryllium sources.
The radiation levels at the surface of the suberitical assembly are tabulated in Fig. 4 page 9 with one of the sources located in the center of the core.
From calculations of fission product buildup presented in the Appendix
=
and the radiation levels of Fig. 5 it is determined that there is no hazard associated with handling the core; therefore, the core is simply handled by hand when changing reflectors. Swipe tests on surface of polyethylene envelope enclosing the core show that no measurable activity has leaked E --
through the envelope.
'S
e POSITION SOURCE RADIATION 1
2 3
4 METER TYPE BARE 3 " POLY 6" POLY G'RAPHITE M-797 S
l 0
0 0
0 S U-14 T W 4
f S+y limr/ hr 6 m r/ hr 3 m r/hr limr/ h r S U-14 T W 2
2 2
n(Thermal) 220/cm sec UNDET.
I20/cm sec 45.im sec FOILS NONE S
O O
O O
S U -14 T W l
S+7 1.2 mr / h r O
O O
S U - 14TW FIGUR E 4 '
-~
APPENDIX 1)
ESTIMATION OF FISSION PRODUCT BUILDUP IN SUBCRITICAL ASSEMBLY The measurements of the thermal flux pattern in the core can be fitted approximately by n = (50 x 10- /r) sin (0.18r) for a source strength of 1.6 x 10 neutrons /second.
The number of fissions per second in the core is given by E 6dv.
To make f
calculation simple, the expression n = A sin Br is fitted to the r
axial neutron density.
The constants are A = 50 x 10-neutrons /cm and B = 0.18cm-The fission cross section E is 0.04]em-from f
the core composition and v is 2.2 x 10 cm/sec.
The number of fissions per second is then calculated to be 4.37 x 10 fissions /
second.
Since 180 mov of energy is liberated per fission the power level is obtained by (1.80 mev/ fission) x (1.60 x 10" joules /mev) x (4.37 x 10 fiesions/second) giving 12.7 x 10-watts for a source of 1.6 x 10 neutrons /second.
Thus source M-797 will produce 14.7 x 10-watts having a source strength of 1.81 x 10 neutrons /sec.
Further calculations are done with M-799 source this being the largest source used.
If this source had been inserted on the day of arrival of the assembly in early 1959 it would have kept the core at power for 10 years x (365 days / year).x (86,400 second/ day) or 3.15 x 10 seconds.
The integrated power level times time would then total 2.2 x 10 watt-sec.
However, the scheduled use at this time of the core with a source is for approximately 50 hrs / semester.
The core has been
used in 20 semesters with varying usable or a total of approximately 3000 hrs or 1.08 x 10 seconds.
The total number of fissions to date 4
6 is thus approximately (4.37 x 10 fission /sec/1.6 x 10 neutrons /
sec 8.82 x 10 neutrons /sec) x (1.08 x 10 sec) = 2.61 x 10 fissions.
According to results given by J. F.
Perkins and R. W. King, " Energy Release from Decay of Fission Products", Nuclear Science and Eno in ee ri ng, 1958, the beta disintegration rate per fission is 10~
on the average.
After 100 days the disintegration rate is 10~
From this it is determined that the present beta decay rate of accumulated fission products is no more than 10~
x 2.61 x lb or 2.61 x 10 disintegrations /sec or less than 3 microcuries of a
fission product activity.
All the estimates above are extremely
' conservative and we are confident that the actual fission product activity is far below the velue calculated here.
13343