ML14125A293

Written Communication as Required by University of Missouri Research Reactor Technical Specification 6.1.h(2) Regarding a Deviation from Technical Specifications 3.5.a

ML14125A293
Person / Time
Site:	University of Missouri-Columbia
Issue date:	05/02/2014
From:	Rhonda Butler Univ of Missouri - Columbia
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14125A293 (5)

Text

UNIVERSITY of MISSOURI RESEARCH REACTOR CENTER May 2, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P 1-37 Washington, DC 20555-0001

REFERENCE:

Docket No. 50-186 University of Missouri-Columbia Research Reactor Amended Facility License R-103

SUBJECT:

Written communication as required by University of Missouri Research Reactor Technical Specification 6.1.h(2) regarding a deviation from Technical Specifications 3.5.a The attached document provides the University of Missouri-Columbia Research Reactor (MURR) Licensee Event Report (LER) for an event that occurred on April 7, 2014, that resulted in a deviation from MURR Technical Specification 3.5.a.

If you have any questions regarding this report, please contact John L. Fruits, the facility Reactor Manager, at (573) 882-5319.

Sincerely, Ralph A. Butler, P.E.

Director RAB:jlb Enclosure xc: Reactor Advisory Committee Reactor Safety Subcommittee Dr. Kenneth Dean, Deputy Provost Mr. Alexander Adams, Jr., U.S. NRC 02-0 Mr. Johnny Eads, U.S. NRC 911 E-10-)

1513 Research Park Drive Columbia, MO 65211 Phone: 573-882-4211 Fax: 573-882-6360 Web: www.murr.missouri.edu Fighting Cancer with Tomorrow's Technology

Attachment U.S. Nuclear Regulatory Commission May 2, 2014 Licensee Event Report No. 14 April 7, 2014 University of Missouri Research Reactor Introduction On April 7, 2014, with the reactor shutdown for regularly scheduled maintenance activities, the facility exhaust ventilation system low flow alarm was being tested as part of the pre-startup checks prior to conducting a normal reactor startup. During this time, Master Control Switch IS1 was in the "Test" position in order to complete preventive maintenance on Pool Coolant Circulation Pump P-508A. With switch ISI in the "Test" position, the reactor was not in the secured condition as defined by Technical Specification (TS) 1.20. When the exhaust ventilation fans were secured, this created a situation where one of the six (6) conditions for reactor containment integrity to exist was not satisfied. TS 3.5.a requires that reactor containment integrity shall be maintained at all times except when (1) the reactor is secured, and (2) irradiated fuel with a decay time of less than sixty days is not being handled. Immediately upon receipt of the low flow alarm, the exhaust ventilation fan was restarted and reactor containment integrity reestablished.

As defined by TS 1.15, six conditions must be satisfied for reactor containment integrity to exist.

One of these six conditions is "The reactor mechanical equipment room exhaust system, including the particulate and halogen filters, is operable." Because the facility exhaust ventilation fans EF-13 and EF-14 were secured to initiate the low flow alarm, a no flow condition was momentarily present in the mechanical equipment room exhaust system particulate and halogen filters, as such the system was considered to be in a degraded condition.

For approximately five seconds, the reactor was not secured while reactor containment integrity did not exist.

Description of the Relationship between Reactor Containment Integrity and Reactor Secured Reactor containment integrity is defined in TS 1.15 as follows:

"For reactorcontainment integrity to exist, the following conditions must be satisfied.-

a. The truck entry door closed and sealed

b. The utility seal trench filled with water to the depth required to maintain a minimum water seal of 4. 25feet.

c. All containment building ventilation system automatically-closing doors and automatically-closingvalves are operable or placed in the closedposition.

d The reactor mechanical equipment room exhaust system, including the particulate and halogen filters, is operable.

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Attachment U.S. Nuclear Regulatory Commission May 2, 2014

e. The personnel airlock door operable.

f The most recent building leak test was satisfactory."

As stated in TS 3.5.a, "Containment integrity shall be maintainedat all times except when.

(1) The reactor is secured,and (2) Irradiatedfuel with a decay time of less than sixty (60) days is not being handled" For the reactor to be secured it must meet all of the following requirements stipulated in TS 1.20:

"The reactor shall be considered secured whenever it contains insufficient fuel in the reactor core to establish criticality with all control rods removed or whenever all of the following conditions are met.

a. All shim rods arefully inserted.

b. One of the following conditions exists:

(1) The "Master Control" switch is in the "off' position with the key locked in the key box or in the custody of a licensed operator.

(2) A licensed operator is present in the Control Room and the dummy load control rod test connectors are installed.

c. No work is in progress involving transferringfuel in or out of the core.

d No work is in progress involving the control rods or control rod drives with the exception of installing or removing dummy load control rode test connectors.

e. The reactorpressure vessel cover is secured in position and no work is in progress on the pressure vessel or its supports. "

In order to meet the requirements of TS 3.5.a, the requirements for reactor containment integrity (TS 1.15) or the requirements for the reactor being secured (TS 1.20) must be met.

In the instance on April 7, TS 1.1 5.d was not met; therefore, reactor containment integrity did not exist. Hence, TS 1.20.b was not met and the reactor was not considered secured. These two conditions combined caused a deviation from the requirements of TS 3.5.a.

Detailed Event Description At approximately 15:05 on April 7, 2014, with the reactor shutdown for regularly scheduled maintenance activities, the facility exhaust ventilation system low flow alarm was being tested as part of the pre-startup checks prior to conducting a normal reactor startup. At the same time, Master Control Switch IS 1 was in the "Test" position as part of placing the pool coolant system on-line to complete preventive maintenance on Pool Coolant Circulation Pump P-508A. With switch IS I in the "Test" position without the dummy load control rod test connectors installed, the reactor was not secured. When the exhaust ventilation fans were secured during performance Page 2 of 4

Attachment U.S. Nuclear Regulatory Commission May 2, 2014 of operator aid OA-1, "Facility Exhaust Fans EF-13 and EF-14, EF-13 Running," as required by a step on form FM-57, "Long Form Startup Checksheet," this caused a condition where reactor containment integrity was not met. TS 3.5.a requires that reactor containment integrity shall be maintained at all times except when (1) the reactor is secured, and (2) irradiated fuel with a decay time of less than sixty days is not being handled. Immediately upon receipt of the low flow alarm the control room operators identified the degraded condition and an exhaust ventilation fan was restarted which re-established reactor containment integrity.

Safety Analysis The basis for TS 3.5.a is to assure that the reactor containment building can be isolated at all times except when the plant conditions are such that the probability of release of radioactivity is negligible. The reactor containment integrity condition which requires that the mechanical equipment room exhaust system to be operable, including halogen and particulate filters, is based on mitigating the consequences of a release of radioactivity to the mechanical equipment room during an accident scenario involving fuel failure. Hazards Summary Report, Addendum 4, Appendix C, states that no accident other than the hypothetical Design Basis Accident (DBA) would result in a release of fission products from the fuel. The DBA is selected to postulate conditions which lead to consequences worse than those resulting from any credible accident associated with operating the reactor. With the reactor shutdown, no credible mechanism for a fuel failure accident exists and thus, the probability of release of radioactivity from the mechanical equipment room should be negligible. Therefore, the degraded condition of the exhaust ventilation system for the mechanical equipment room was a deviation from the performance specification provided in TS 3.5.a but did not represent an undue safety hazard or concern for the reactor, staff or general public.

Corrective Actions When the control room Fan Failure Alarm Panel audible alarm sounded, the control room operators immediately recognized the deviation and an exhaust ventilation fan was restarted in slow speed. This restored flow through the mechanical equipment room exhaust system and satisfied the requirements of TS 1.15. The pool coolant system was shutdown and Master Control Switch 1S1 was placed in the "Off' position with the key removed.

The Reactor Manager stopped all work in progress and convened all reactor operators involved with the maintenance activities. The Reactor Manager and Assistant Reactor Manager -

Operations discussed the event in detail with the operators and potential corrective actions. The Reactor Manager met with the individuals directly involved with the oversight of the evolutions and counseled them on the severity of the incident.

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Attachment U.S. Nuclear Regulatory Commission May 2, 2014 A direct contributing factor to the incident was the routine nature of the activity and the failure to adhere to the prescribed procedures and operator aids. The current operator aids, OA-1, "Facility Exhaust Fans EF-13 and EF-14, EF-13 Running," and OA-2, "Facility Exhaust Fans EF-13 and EF-14, EF-14 Running," have been obsoleted. Reactor operating procedure RO-OP-730, "Building Exhaust System Fans," has been revised to provide more stringent control of the activity by the control room operator and provide for specific steps in the procedure to ensure the reactor is secured prior to securing exhaust ventilation fans by the control room operator and Lead Senior Reactor Operator (LSRO). FM-57, "The Long Form Startup Checksheet," has also been revised to relocate the step for testing the Fan Failure Alarm System in the Reactor Experiment, Instrumentation and Controls section.

In addition, the Reactor Manager will meet with all Reactor Operations Staff to ensure that all individuals are aware of the severity of this event and to re-enforce the requirement for strict procedural compliance.

If there are any questions regarding this LER, please contact me at (573) 882-5319. 1 declare under penalty of perjury that the foregoing is true and correct.

ENDORSEMENT:

Sincerely, Reviewed and Approved, John L. Fruits Ralph A. Butler, P.E.

Reactor Manager Director /

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