ML20040B758

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Annual Operating Rept,1981.
ML20040B758
Person / Time
Site: 05000262
Issue date: 01/04/1982
From: Dixon D
Brigham Young University, PROVO, UT
To:
Shared Package
ML20040B745 List:
References
NUDOCS 8201260388
Download: ML20040B758 (3)


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Annual Operating Report for 1981 Brigham Young University L-77 Reactor Facility 4 Jan 1982 A. Narrative summary of reactor operating experience.

The L-77 reactor was operated 37 tincs during the calendar 1981 with a total energy production of 304 watt-hours.

Reactor use fell generally into three areas. First, the reactor-physics laLoratory class, Physics 557, was given during the spring term, and exercises in that class included training in reactor operation, rod-worth calibrat ions, neutron activation, flux and power measurements, cross-section measurements, and measurements of delayed-neutron precursor half-lives. Secondly, several operations for maintenance or operator practice runs were performed. Thirdly, twenty f3ur operations were for activation 29 Al, 39 of 24 Na, and C1 samples for use in measuring the gamma-ray response of 6Li glass.

B. t:nscheduled shutdowns.

There were seven unscheduled shutdowns during 1981. Five of these occurred at near-shutdown pouer levels during start-up operation; these occurred mainly from c.tudent unf amiliarity with instrument behavior. Two occurred during operation near ten watts, when transients in one of the log micro-microammeters resulted in a short-period scram; in both cases the actual power level was constant. The cause of those transients has l

now been elininated. In none of the seven cares was there any safety 1

l problem whatsoever.

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2 C. Surveillagee_ tests.

All safety circuits associated with the reactor were tested and found t o b e no rma l . Control-rod-drop t imes were well within the 0.5-second limit.

Control-rod worth calibrations were consistent with previous determinations.

One recent power calibration check showed that at a nominal 1.0 watt the ca lcula t ed ,)ower was 0. 70 wa t t , and a second gave 1.06 watts, also at a nominal 1.0 watt. These are consistent with those of previous years, so the old calibration was retained.

D. Ma in tenance operat_f or!s.

Maintenance work was performed on both log micro-microammeters. Log mete r "A" began to read a false short period, and needed some tube replace-ments and other work. l.og meter "B" developed an instability and resulted in two short-period scrams. This meter spent considerable time in the electronics shop and now appears to be normal. Work on it included replace-ment of a selenium rectifier.

1;. Fac i1 i ty j.nd p_rocedure changes.

The 2-MeV Van de Graaf f accelerator that has occupied portions of the nuclear laboratory was moved in December to another laboratory. The resul-tant unused space will be used for storage of rock samples for the geology department and for locating some mini-computer terminals for the math department.

F. Sa d [gi c,t I ve. _ma t_e r ia l s_ r.q[91s_qd t q t h_q_en v [rgnmqn t,.

None.

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G. Environmental survey outside the facility.

l None.

l 11 . S ign i f ican t radiation exposures.

None.

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Dwight R. Dixon Facility Chief 1

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