ML20040E101
| ML20040E101 | |
| Person / Time | |
|---|---|
| Site: | 05000139 |
| Issue date: | 01/27/1982 |
| From: | WASHINGTON, UNIV. OF, SEATTLE, WA |
| To: | |
| Shared Package | |
| ML20040E100 | List: |
| References | |
| NUDOCS 8202030111 | |
| Download: ML20040E101 (5) | |
Text
-_ _
Annual Report from the University of Washington Facility License R-73 A.
A NARRATIVE Summary of Operating Experience for the Period January 1, 1981 to December 31, 1981 The University of W shington Nuclear Reactor was operated for 204 hours0.00236 days <br />0.0567 hours <br />3.373016e-4 weeks <br />7.7622e-5 months <br /> (baseline -
- shutdown) and generated 11,923 >~a of energy. The 105 experimental runs consisted of sample irradiations for neutron activation analysis, isotope production, class demonstrations, anomaly detection experiments, operator training and testing and calibrations.
B.
Unscheduled Shutdowns 1.
At Power Date Power Level Cause Nov. 20, 1981 1 kw Caused by 110 volt AC noise resulting in photodiode isolation falling beloe operational level in safety amplifier.
C.
Corrective and Preventative Maintenance Ha'ving Safety Significance 1.
Routine calibrations and maintenance as scheduled.
2.
Fuel box gaskets were replaced during September and October 1981. The gaskets on the inlet and outlet headers of the fuel boxes, as well as gaskets on the return line flanges were replaced with similar insterial (95% asbestos 5% neoprene). The shim rod shaf t bearings outside the concrete shield were replaced on shims 1, 2 and 3 at this time. During this maintenance some corrosion was discovered on the exterior of the 8202030111 820127 PDR ADOCK 05000139 R
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. s fuel boxes. *This condition was reported separately by ? etter dated s
s.
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November 2, 198] to NRC Washington with carbon copy to Region V.
Static-headstests were conducted on all fuel boxes before returning s
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them to servica..
s 3.
The constant voltage transformer that supplies the 115 VAC to'the c
s, linear channel, log N channel, area monitors and stack monitors was replacedonDecemper 18, 1981. A voltage degradation was discovered during regu}ar mon,thly. preventative maintenance check so the unit was replaced with a similar one by the same manufacturer.
y 4.
Checking of Shim No. 3 s
' 'During a checkout bn, January 18, lo82 (last operation, December 21,
' 1981), it was' observed during a pre-critical checkout that Shim No. 3 L was dropping ecre slowly th'an the.other shims. A subsequent check
., o indicated that the first drop from 100% was over 1 second.
Sequential 4
drops from 100% were all under 1 second with the 7th being 750 milli-sec, the lowest.
A che.:k of No. 3 drive mechanism and shaft alignment indicated that neither'one was the cause. A drop check on January 19 prior to the pre-cr tica1' checkout (hence no movement of rod before the chec'k)'gave a 1st drop from 100% at slightly over 1 second and all subsequent,,drope l'ess than 1 second.
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Am They suggested that in the Regi' n V NRC of fice was contacted.
o N e r future ve closely observe Shim No. 3 and thac we include our C'
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[T recent observations in this report.
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Our current invcstiga ions indicate that a time between runs s.
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'J andatemperature6['the' core'deptadenceexistsandthattheinner a
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rod beari$bs are probably this(dause~. One correction is to change e,I..
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3 the inner rod bearings which entails unloading the core and being subjected to significant radiation exposures. Until we definitely pin down the cause we will monitor Shim No. 3 closely and look for other colutions.
D.
Discussion of Chsnges Carried Out Pursuant to 10 CFR 50.59 1.
None for 1981.
E.
Radioactive releases to the Environs;
'1 1.
Emptied one retention tank (1440 gallons) to sanitary sewer April 16, l
l 1981, with total activity less than 0.03 microcuries.
2.
The Argon-41 released from the facility during 1981 was measured to be 17 curies.
F.
Environmental Surveys Outside the Facility 1.
Surveys performed with a survey meter Following surveys were performed during_ period of gasket changing on fuel boxes at the windows surrounding the reactor room:
Date Dose Rates Found l
Sept. 21, 1981 Maximum 0.3 mrem /hr i
Sept. 24, 1981 Maximum 0.2 mrem /hr Sept. 25, 1981 Maximum 0.1 mrem /hr Sept. 28, 1981 Maximum 0.1 mrem /hr 2.
Film Badge and TLD Data See following table.
Dosimeter provided by R.S. Landauer, Jr. & Co.
/
.'p
/
4 Table of Film Badge and TLD Data i
Date Monitor Placed in Position Location (")
6/1/81 7/9/81 8/3/81 9/3/81 10/9/81 11/3/81 1
Film M
M M
M M
M i
i TLD 10 20 20 20 M
20
}
I l
2 Film M
M M
M M
M TLD 30 30 20 20 M
20 l
3 Film M
M M
10 10 M
i l
TLD 30 30 20 60 30 20 i
l 4
Film M
M M
30 M
M TLD 40 30 20 80 20 20 5
Film l M
M M
20 M
M TLD 40 40 20 80 20 30 l
40 M
M 6
Film M
M M
i TLD 40 30 20 60 20 20 1
7 Film M
M M
l M
M M
f TLD 30 20 20 30 M
10 l
8 Film M
M M
M M
M l
I i
TLD 30 50 20 20 M
20 l
Dose in Millirem (a)
See First Floor Plan showing locations.
LOCATION OF ENVIRONMENTAL MONITORS
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CLASS
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ROOM l
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N I
s REACTOR l
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(50 feet from building)
NUCLE AR RE ACTOR L ABOR ATORIES FIRST FLOO R PLAN UNIVERSITY of WASHINGTON COLLEGE of ENGINEERING DATE </,
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G. -Sg nificant Exposures (over 500 mrem for Year)
For the year 1981 there were two exposures greater than 500 mrem for the year.
Individual A received 630 narem for the year and B received 1290 mrem 4
as reported by film badge service. All of individual A's exposure and 1280 mrem of. individual l's exposure occurred in September and October during
-fuel box gasket replacement. For the September-October period finger TLD rings gave a reading of 820 mrem and 940 mrem for individual A and 1540 and 1680 mrem for individual B.
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