ML20309A676

Missouri University of Science and Technology - Written Communication as Specified by 10 CFR 50.4 Requesting Approval of an Exigent Amendment to the Technical Specifications Appended to Facility Operating License R-79

ML20309A676
Person / Time
Site:	University of Missouri-Rolla
Issue date:	11/04/2020
From:	Graham J Missouri Univ of Science & Technology
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML20309A676 (4)

Text

MISSOURI Nuclear Engineering and S&T November 4, 2020 Radiation Science ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

REFERENCE:

Docket No. 50-123 Missouri University of Science and Technology Reactor Facility Operating License R-79

SUBJECT:

Written communication as specified by 10 CFR § 50.4 requesting approval of an exigent amendment to the Technical Specifications appended to Facility Operating License R-79 Pursuant to 10 CFR 50.90, the Missouri University of Science and Technology Reactor (license R-79) hereby requests an amendment to the Technical Specifications appended to the Facility Operating License R-79 as a one-time extension of the surveillance interval for TS 4.2.1 2) " Shim/Safety Rods",

up to a year beyond the CUITent requirement due date.

Enclosure 1 provides the precedents and basis for the requested extension.

Approval of the proposed amendment is requested by November 9th 2020. Once approved, the amendment shall be implemented within 1 day. If there are questions regarding this license amendment request, please contact me at grahamjose@mst.edu. I declare under penalty of pe1jury that the foregoing is true and correct.

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Joseph Graham, Ph.D.

II /4/UU>

Reactor Director Missouri University of Science and Technology grahamj ose@mst.edu (573)341-7759 301 West 14lh Street

• 222 Fulton Hall

• Rolla, MO 65409-0170 Phone: 573-341-4720

• Fax: 573-341-6309 Email: nuclear@mst.edu

• Web: nuclear.mst.edu An equal opportunity institution

Enclosure 1 - Precedents and Basis for the Requested Extension to TS 4.2.1 2) 1.0 Introduction The Missouri University of Science and Technology Reactor (MSTR) is requesting an amendment to Technical Specification 4.2.1 Shim/Safety Rods, as a one-time extension of the surveillance requirement on visual inspection of the shim/safety rods up to one year beyond the current requirement due date. Due to ongoing issues with a malfunctioning fission chamber and its associated channel, the reactor is currently inoperable until repairs can be made. Per TS 14.6.4 Operating Procedures, the reactor staff shall follow written procedures for fuel and control rod movements that require the use of an operable fission chamber. The use of the fission chamber ensures safe fuel movement and unloading of control rod elements. Control rod visual inspections are due by November 12th 2020. In its current, inoperable condition, removal of control rods from the MSTR for inspection is not possible and it is now becoming likely that the facility will be in violation of its Technical Specifications on the grounds of failing to perform required surveillance within the surveillance interval. A one-year extension of the surveillance requirement to November 12th 2021 will provide ample time to complete the surveillance requirement after repairs to the fission chamber can be made.

2.0 Background

The Technical Specifications amended to the Facility Operating License states the following surveillance requirements on the shim/safety rods, TS 4.2.1 Applicability: This specification applies to the surveillance requirements for the shim/safety rods.

Objectives: To ensure that the control rods are capable of performing their function and to establish that no significant physical degradation in the rods has occurred.

Specifications:

1) Shim/safety rod drop times shall be measured as follows: a) semiannually b) for a particular control rod, whenever the magnet assembly is disassembled or reassembled, or if the control assembly is moved to a new grid position

2) The shim/safety rods shall be visually inspected annually for pitting and cracking and whenever rod drop times exceed the LCOs (Section 3.2.3 of these specifications).

Bases:

1) Rod drop-time measurements are required to ensure the reactor can be quickly shut down.

2) The visual inspection of the shim/safety rods and measurement of their drop times are made to determine whether they are capable of performing properly and to detect any gradual degradation in rod performance.

TS 14.6.4 Operating Procedures states The reactor staff shall prepare and use written procedures for at least the items listed below. These procedures shall be adequate to ensure the safe operation of the reactor but should not preclude the use of independent judgment and action, should the situation require it.

(1) startup, operation, and shutdown of the reactor 1

Enclosure 1 - Precedents and Basis for the Requested Extension to TS 4.2.1 2)

(2) installation or removal of fuel elements, control rods, experiments, and experimental facilities (3) actions to be taken to correct specific and foreseen potential malfunctions of systems or components, including responses to alarms, suspected coolant system leaks, and abnormal reactivity changes (4) emergency conditions involving a potential or actual release of radioactivity, including provisions for evacuation, reentry, recovery, and medical support (5) preventive and corrective maintenance operations that could have an effect on reactor safety (6) periodic surveillance (including testing and calibration) of reactor instrumentation and safety systems (7) radiation control procedures, which shall be maintained and made available to all operations personnel (8) implementation of emergency and physical security plans Items (2) and (6) are addressed through Standard Operating Procedures (SOPs) 302 Inspection of Control Rod and 207 Fuel Handling. SOP 102 Pre-startup Checklist Procedures, which is pre-requisite to SOP 207, requires verification of fission chamber response. Without an operable fission chamber, it is not possible to move fuel elements per SOPs 102 and 207 in order to partially or fully unload the core. Unless the core can be unloaded, it is not possible to remove control rod elements for inspection under SOP 302. Therefore, control rod removal and inspection is dependent on having an operable fission chamber.

3.0 Justification The requested extension will have negligible impact on reactor safety. Previous control rod visual inspections revealed minimal pitting/fretting and no cracking. Since the last visual inspection, the total energy generation of the MSTR has been low. It is exceedingly unlikely that a significant change has occurred to any of the shim/safety rods that could lead to a reactivity insertion while the reactor is in a secured or shutdown condition. Moreover, until the fission chamber is repaired or replaced, the reactor will continue to remain in a secured or shutdown condition and therefore no further irradiation of or significant manipulation of the control rods will occur.

4.0 Precedents

Three similar one-year extensions were granted to the MSTR through license amendments 12 (July 30, 1993), 13 (August 17, 1994), and 14 (August 28, 1995). Those extensions were applied to the same surveillance requirement, 4.2.1 2) for reason of being unable to move fuel to the fuel storage 2

Enclosure 1 - Precedents and Basis for the Requested Extension to TS 4.2.1 2) pit. The present circumstances differ in that fuel movement cannot be performed due to a malfunctioning fission chamber, while the delay in fuel movements from 1993-1995 were the result of insufficient fuel pit storage space during the facilities HEU to LEU conversion. Nevertheless, the inability to unload the core as being the reason for the delay in conducting control rod visual inspections is common factor necessitating this license amendment request.

5.0 Proposed Amendment to Technical Specification 4.2.1 Technical Specification 4.2.1 currently states Applicability: This specification applies to the surveillance requirements for the shim/safety rods.

Objectives: To ensure that the control rods are capable of performing their function and to establish that no significant physical degradation in the rods has occurred.

Specifications:

1) Shim/safety rod drop times shall be measured as follows:a) semiannually b) for a particular control rod, whenever the magnet assembly is disassembled or reassembled, or if the control assembly is moved to a new grid position

2) The shim/safety rods shall be visually inspected annually for pitting and cracking and whenever rod drop times exceed the LCOs (Section 3.2.3 of these specifications).

Specification 4.2.1 will be revised to include an asterisk on specification 4.2.1 2) to a footnote stating:

This visual inspection shall be conducted before November 12, 2021, or within four months after the startup channel is made operable so that pre-startup checklists procedures and fuel movement procedures can be performed.

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