ML19273B350
| ML19273B350 | |
| Person / Time | |
|---|---|
| Site: | 05000538 |
| Issue date: | 03/13/1979 |
| From: | Dietz R MEMPHIS STATE UNIV., MEMPHIS, TN |
| To: | |
| Shared Package | |
| ML19273B347 | List: |
| References | |
| NUDOCS 7904060160 | |
| Download: ML19273B350 (4) | |
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MEf4PHIS STATE UtlIVERSITY AGll-201 tiUCLEAR REACTOR FACILITY LICEllSE R-127, DOCKET t10.
50-538 FOLLOW-UP REPORT TO REPORTABLE OCCURRENCE No. 79-2 Date of Report:
March 10, 1979 Date of Occurrence:
March 5, 1979 Date NRC flotification:
March 5, 1979 1.
Reac'or.
151-201, serial 108. Located at the Center for Nuclear Studies, Memphis State University, Memphis, Tennessee.
Facility Operating License R-127, Docket No. 50-538.
2.
Reportable Occurrence.
Electric power service to the Memphis State University South Campus was momentarily interrupted. The unscheduled power outage occurred during AGtl-201 reactor operat:on and, as a direct result of the event, caused reactor shlJtdowr, in the form of a silent reactor scram.
Item 6.9.2.a.(7) of the Facilit; lechnical Specifications applies.
3.
Conditions at Time of Occurrence.
a.
An operator training program was in progress for the purpose of providing reactor startup experient.e for prospective licensees.
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b.
The reactor was supercritical with period 382 seconds (neutron source inserted) at a power level of 2.5 milliWatts.
Safety Rods were fully inserted (24 cm), Coarse Control Rod at 23 cm, Fine Control Rod at U
16.12 cm, and reactor temperature was 19.6 C,
- 4. Narrative At 11:29 a.m., CST, on March 5,1979, a momentary electrical power outage, with immediate restoration of electric power, occurred to the entire South Campus of Memphis State University.
The AGN-201 Reactor, located on South Campus, was being operated by a student operator under the direct supervi-sion of licensed Senior Operators.
At the time of the unplanned event, the operator was increasing reactor power to achieve a convenient level at which to obtain precise delayed critical data to complete reactor startup procedural requirements and to verify an estimated critical rod position previously calculated by the student.
This exercise was being conducted as part of an approved operator training program.
The reactor scrammed, as designed and as required by technical specifi-cations, due to loss of control power which interrupted electrical current to the Control Rod Holding Magnets.
The sound of the Safety and Coarse Control Rods contacting their dashpots (fully withdrawn position) was immediately heard by the operator and Senior Operators in the Control Room via a microphone located in the reactor skirt area.
The Fine Control Rod, which has no scram function, remained inserted to 16.12 cm, and the Safety and Coarse Rod Magnet Assemblies remained at the pre-scram positions.
All console instrumentation, alarms, and safety circuits were momentarily deenergized and immediately reenergized.
Reactor Control Power remained deenergized, as designed, due te the Low Voltage Protected (LVP) tiain Control Power Relay which can only be reset by manual operator action.
Reactor Control Power was reenergized ty the operator to permit the Safety and Coarse Rod Magnet Assemblies ard the Fine Control Rod to be returned to their fully withdrawn limits. The nomal Reactor Shutd.own Checkoff Procedure (0P-5) was completed at 11:42 a.m., CST.
All three channels of neutron flux monitoring instrumentation indicated the normal shutdown neutron level.
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The Reactor Supervisor was in the control room at the time of the unplanned event.
The facility Director was inmediately notified.
The event was reported to the USNRC Region II, Office of Inspection and Enforcement, via telephone conversation between the CNS Operations Supervisor and Mr. Cottle (2:05 p.m., CST), and confirmed by mailgram to the Director, USNRC Region II (3:23 p.m., EST) in compliance with section 6.9.2.a of the Facility Technical Specifications.
The reactor Prestartup Checkoff Procedure (0P-2) was performed and no abnormalities were noted.
Reactor operation resumed at 1:32 p.m.,
CST, March 5, 1979.
5.
Safety Significance of the Occurrence None. A loss of electrical pswer de-energizes the Safety and Coarse Control Rod Holding Magnets causing a reactor scram and thus assures safe and immediate shutdown in case of a power outage.
Reactor systems performed as designed and as required by technical specification 3.3.
6.
Cause of Failure The momentary interruption of electrical power was caused by a power perturbation of unknown origin at Memphis Light, Gas and Water Company substation No. 42, which provides electrical service to the MSU South Canpus.
7.
Corrective Action None.
Corrective action to restore and maintain the South Campus electric service feeder is under the cognizance and control of oroanizat'ons outside the Center for Nuclear Studies and the AGN-201 Reactor Facility.
8.
Measures to Prevent Recurrence None.
Measures to prevent.ecurrence of an electric power outage of the nature described in this report are not within the capabilities of the Center for Nuclear Studies or AGN-201 reactor Facility staff.
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i 9.
Similar Reportable Occurrences.
115U Follow-up Report #79-1 dated January 29, 1979.
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Prepared by:
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Reactor Supe visor s
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