ML20248G624

Ro:On 890302,reactor Operated for 2 H & 33 Minutes W/ Emergency Generator Local Switch in Stop Position.Caused by Personnel Error.Subj Local Switch Placed in Remote Position. Operator Involved Counseled.Checksheet Revised

ML20248G624
Person / Time
Site:	University of Missouri-Columbia
Issue date:	03/28/1989
From:	Mckibben J, Meyer W MISSOURI, UNIV. OF, COLUMBIA, MO
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8904130511
Download: ML20248G624 (3)

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I UNIVERSITY OF MISSOURI March 28, 1989 Research Reactor Facility l Research Park Columbia, Missouri 65211 Telephone (314) 882 4211 Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D. C. 20555

REFERENCE:

Docket 50-186 University of Missouri Research Reactor License R-103

SUBJECT:

Report as required by Technical Specification 6.1.h(2) concerning reactor operations with the emergency generator operable but in a degraded state.

DESCRIPTION:

On March 2, 1989 the reactor operated for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 33 minutes with the Emergency Generator (EG) local switch in the ST0_p_ position. This local three position switch (RUN/STOP/ REMOTE) is required to be in the REMOTE _ position for the EG to iatomatically start and assume emergency electrical loads after a loss of facility electrical power.

Operation of the reactor with the EG local switch in the wrong position for automatic operation deviates from Technical Specification 3.10(a) which states "the reactor shall not bc Operated unless the emergency electrical generator is operable." Operable as defined in Technical Specifications means capable of performing its intended function in a normal manner. Although the EG was capable of being operated within a few minutes had a loss of electrical power occurred, it was in a degraded condition since it would have required operator manual inter-vention for it to start and assume emergency electrical loads instead of starting automatically.

ANALYSIS:

The EG is a 45 KVA generator powered by a Ford 292 cubic inch gasoline vgir,'

with a one barrel carburetor fuel system and a 12 volt electric choke.

Technical Specification surveillance requirements include a full load test (Compliance Procedure #17) of the EG at a semi-annual frequency and a test of the operability prior to each startup following a shutdown greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

During extended operation, the operability is to be verified on a weekly basis.

MURR meets or exceeds these requirements by performing a monthly EG load test (CP #17) and by exercising the EG automatically the morning of each weekly shut-down for maintenance and refueling.

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. Director of. Nuclear Reactor Regulation March 28, 1989 Page 2 The EG is also exercised for 30 minutes as part of the Full Power Startup Checksheet completed prior to the reactor startup. This is normally accomplished by placing the EG local switch to the RUN position. Following a 30 minute run period, the reactor operator performing the startup checksheet secures the EG by going i a the STOP position, allows the engine to coast to a stop, and then places the switcc in the REMOTE position, which enables the generator to start auto-matically when site electrical power is lost.

In reviewing the situation with the operating crew, the following was deter-mined. The operator performing the startup checksheet, while securing the EG from its 30 minute exercise, thought the valve lifters for the EG engine were louder than normal. He placed the EG local switch to STOP, allowed the engine to stop, and checked the engine for sufficient oil level. After finding the oil level normal and performing a visual check of the EG, he concluded that there was nothing wrong with the EG. He then forgot to place the local switch to the REMOTE position.

In this condition, the EG would not have responded automatically to a loss of electrical power. If a loss of electrical power had occurred during this 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> j and 33 minute period of time, an operator would have been sent to inv9stigate why the EG had not started automatically and would have been able to start the EG and supply emergency electrical loads within a few minutes by placing the local switch to the REMOTE position.

An evaluation of the Full Power Startup Checksheet revealed that the step that calls for the EG test is actually a redundant test, whenever the reactor is shutdown less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, since the EG is scheduled to run on its weekly exerciser the n'orning of each scheduled maintenance day. Performing the test run, which calls for removing the EG from its normal lineup (from REMOT_E_ to RUN), creates a situation where the risk of not getting the switch back to its normal position is much greater than any benefit gained by a second 30 minute run of the EG. For shttdowns less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration, a more appropriate step in performing a normal Full Power Startup Checksheet would be to ensure that the EG is in its paper lineup for opera-tion, that is, to check that the local switch is in REMOTE. For shutdowns greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the manual test prior to startup would continue to be performed.

The analysis for loss of electrical power with the reactor operating at 10MW and the emergency generator failing to start is covered in Hazards Summary Report (HRS), Addendum 5, Section 2.4.1, 2.4.2, and 2.5. In this dual failure mode, the reactor will shut down if not already shut down and decay heat removal will be per-formed indefinitely / the in-pool heat exchanger. The control blades are released on loss of electrical current to their electromagnets and drop to the full inserted position by gravity. All process systems are placed in the shutdown condition due to the failsafe design of these systems; i.e. the redundant (only one is required) primary in-pool heat exchanger valves 546 A and B open by spring actuation, placing the convection cooling in-pool heat exchanger in service. This failsafe design of the system permits shutdown decay heat removal with no electrical power (Appendix D of Addendum 4 to HSR). The containment building integrity could not be indefinitely guaranteed if facility electrical power and emergency generator were not available, but the reactor would be shut down and containment would not be required.

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l Director of Nuclear Reactor Regulation L March 28, 1989

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CORRECTIVE ACTION:

The immediate corrective action was to place the EG local switch to the REMOTE positioi. This placed the EG in its normal condition, enabling it to respond auto-matically to any loss of facility electrical power.

The operator involved was counselled by both his shift supervisor and the Operations Engineer about the significance of leaving the EG switch in the wrong position, as well as, the importance of paying attention to details when performing licensed tasks.

The steps in the Full Power Startup Checksheet that calls for a redundant test of the EG on shutdowns of less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> duration, will be replaced with a step that checks the EG local switch in the REMOTE position. For shutdowns greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the manual test prior to startup will continue to be performed.

Sincerely, Walt A. Meyer, J Reactor Manager ENDORSEMENT: M G

Reviewed and Approved

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