ML20079R602
| ML20079R602 | |
| Person / Time | |
|---|---|
| Site: | 05000433 |
| Issue date: | 01/24/1984 |
| From: | Kroes R, Profio A CALIFORNIA, UNIV. OF, SANTA BARBARA, CA |
| To: | NRC |
| References | |
| NUDOCS 8402020302 | |
| Download: ML20079R602 (5) | |
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.i UNIVERSITY OF CALIFORNIA, SANTA BARBARA i
L-77 REACTOR i
ANNUAL REPORT OF OPERATIONS January 1,1983 through December 31, 1983 License R--124 Docket No. 50-433 '
s A.E. Profio, Reactor Director January 24, 1984 . ,
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ld Operating Experience, Changes and Tests This is the ninth annual report for the 10 watt, L-77 training reactor at the University of California, Santa Barbara. The reactor is operated mainly for instruction in nuclear engineering and for occasional neutron activation irradiations.
The L-77 reactor is the principal facility for the NE125 Neutronics Lab-oratory course. The course is required for all B.S. degree majors in nuclear engineering, and may be taken as an elective by graduate students or majors in other fields. In 1983, twelve students took the course for credit.
2speriments include power calibration by flux plotting, control rod reactivity calibrations by suberitical multiplication and supercritical period measure-ments, reactivity-worth (importance) of neutron absorbing and scattering samples at different positions within the through-co'r e tube, approach to critical, and neutron activation. Students operate the reactor under the supervision of a licensed operator (A.E. Profio). the lab is offered in the Spring Quarter (April-June), once or twice a week according to enrollment.
Senior Operator A.E. Profio is currently the only licensed operator, but a staff suployee (Victor Thomas) was being trained as an operator until he left in September 1983. He has been replaced and the new employee will be trained.
The reactor operator or technician performs the weekly alarm checks as well as maintenance of the reactor and instruments with the help of other department employees.
There were no significant changcs in the facility in 1983. New area rad-iation monitors (Eberline) were installed to replace the obsolete and troublesome (f alse alarms) Tracerlab area radiation monitors.
The annual power calibration was performed on 5-18-83 (calibration was same as in previous years) . The annual control rod worth and speed tests were performed on 6-23-83. The control rod mechanisms were due to be inspected and serviced after 12-10-82 (planned for January or February 1984) . Tne annual radiation monitor and air monitor calibrations and servicing were due after 12-17-83 (planned for January or February 1984) . The seismic trip calibration / test was due after 11-18-83 (done in January 1984) . The tank and console maintenance ,
and inspection was done on 1-5-83. All items passed the tests.
The semiannual rod drop time tests were performed on 2-16-83 and 9-30-83.
Rod drop times were within specifications. The core-recombiner pressure scram test and calibration was carried out on 5-9-83 (and on 1-5-84) . The shield water level scram was tested on the same dates. The flux instrumentation and recorder were calibrated and serviced on 3-28-83 and 11-28-83. The radiation level and contamination surveys were carried out by the Campus Radiation Safety Officer (Frank Gallagher) and assistant on 6-23-83, and was due after 12-23-83 (planned for February 1984) . Alarms were checked weekly.
Unscheduled Shutdowns and Scrams 2-16-83: spurious log n level scram on lowering control rod.
3-16-83: spurious scram on leveling of f ,at power.
3-30-83: spurious period scram with reactor subcritical.
5-11-83: spurious scram on switching range en picoammeter (turned wrong way) .
6-23-83: spurious scram on leveling off at power.
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'r Except for the range switching error, the scrams occured with moving the control rod (even in), because of electrical transients from the relays or switch contacts, and a very sensitive log n and period amplifier. Efforts continued to eliminate the problem but spurious scrams may still occur.
Preventive and Corrective Maintenance Operations Routine preventive and corrective maintenance operations were performed according to the Operations Manual. The main corrective maintenance needed was related to be spurious scram problem. In additon to the maintenance of relays and switch contacts, grounding, and isolation, a modified test signal generator for log n, period, and linera flux scram testing was installed.
The problem, however, was not solved completely.
There were a number of radiationand security (intrusion) alarms, all false:
1-8-83: high area radiation alarm and loss-of-vacuum alarm, because of campus power failure. r 1-29-83: radiation alarm because of power outage.
2-11-83: security alarm, area secure, cadse unknown.
2-23-83: security alarm, worker bypassed alarm incorrectly.
2-24-83: security alarm, suspect moisture in cable to Dispatcher (rain) .
3-18-83: radiation alarm, power failure.
5-14-83: security alarm, all secure, cause unknown.
9-13-83: radiation alarm, power outage.
10-26-83: security alarm, all secure, cause unknown.
11-9-83: security alarm,all secure, possibly tripped by machinery in FEL.
12-25-83: security alarm, all secure, perhaps set off by storm.
Except for power outages, radiation alarms are performing satisfactorily.
The increased incidence of securiy alarms to Police Dispatch Office may be caused by power outage, storm related problems, or interference fram the FEL (Free Electron- Laser lab nextdoor) which may be momentarily changing g line voltage or vibrating the motion detector when the FEL starts up.
- The problem is being investigated.
Changes Under 10 CFR 50.59 None.
Radioactive Effluents Discharged-
- Liquid wastes
- none.
l Solid wastes: Very low level contaminated gloves and similar items disposed to l radwaste container for pickup and off-site disposal by contractor, through
! Environmental Health and Safety office on campus.
Gateous wastes: Not discharged during operation as core-recombiner vessel l is sealed and under vacuum. The core-recombiner vacuum (pressure) gage is
- recalibrated, and the loss-of-vacuum alarm and trip are tested semiannually t
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by admitting air'. Then the vessel is reevacuated into a holdup tank for decay over the 6 months or more between tests. Short lived activities in the vessel gas space decay between tests, but some 10.4 year half-life krypton-85 is discharged to the atznosphere, mixed with room exhaust, when the holdup tank is evacuated. Calculations based on watt-hours of operation, fission yield of krypton-85, and conservatively neglecting radioactive decay, give for activity discharged in 1983: 0.39 microcurie, negligible health effect.
Environmental Surveys Done Outside Facility Radiation levels are measured immediately outside the facility as part of the semiannual radiation-contamination survey. All were at background level or lowest measurable (less than 0.1 mR/hr) .
Significant Radiation Exposure None.
Energy Output in 1983; 1
3.4 watt-hours.
Hours Critical in 1983 10.6 Energy Output Since Initial Criticality 327.4 watt-hours or 13.6 watt-days.
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sta en m . m a. . . .svaa. = m.o . wo una saw na . a na car David Pit rient Gardner OFFICE OF Tile Cil ANCELIDR JYrsident of tat Unirrrrity SANTA ItARitARA. CALIFORNIA 93106 Robert A. Iluttenback Chantrifor at Santa Barbara January 30, 1984 1
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Facility Licensing Branch U.S. Nuclear Regulatory Commission Washington, D.C. 20555 j
REF: Docket 50-433. License R-124
, SIRS:
Enclosed are 21 copies of the Annual Report of Operations for the 1983 calendar year, for the L-77 training reactor at the University of California, Santa Barbara.
Sincerely, Robert J. Kroes Vice Chancellor
, Administrative Services
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cc: A.E. Profio F.E. Gallagher j
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