ML15219A471

University of Maryland - Request for Additional Information for License Renewal of the Maryland University Training Reactor Pertaining to Thermal Hydraulics

ML15219A471
Person / Time
Site:	University of Maryland
Issue date:	09/10/2015
From:	Cindy Montgomery Division of Policy and Rulemaking
To:	Koeth T Univ of Maryland - College Park
Allen E, NRR/DPR, 415-4246
References
TAC ME1592
Download: ML15219A471 (6)

Text

September 10, 2015 Dr. Timothy W. Koeth, Director Nuclear Reactor and Radiation Facilities Chemical and Nuclear Engineering Building 090 University of Maryland College Park, MD 20742

SUBJECT:

UNIVERSITY OF MARYLAND - REQUEST FOR ADDITIONAL INFORMATION FOR LICENSE RENEWAL OF THE MARYLAND UNIVERSITY TRAINING REACTOR PERTAINING TO THERMAL HYDRAULICS (TAC NO. ME1592)

Dear Dr. Koeth:

The U.S. Nuclear Regulatory Commission (NRC) is continuing its review of your application for the renewal of Facility Operating License No. R-70, for the Maryland University Training Reactor, dated May 12, 2000 (a redacted version of the application is available on the NRCs public Web site at www.nrc.gov under the Agencywide Documents Access and Management System Accession No. ML052910399), as supplemented. During our review, questions have arisen requiring additional information and clarification to complete the review. The specific information requested is addressed in the enclosure to this letter. It is requested that the University of Maryland respond to this request within 30 days from the date of this letter.

In accordance with Title 10 of the Code of Federal Regulations (10CFR) 50.30(b), Oath or affirmation, the University of Maryland must execute its response in a signed original document under oath or affirmation. The University of Marylands response must be submitted in accordance with 10 CFR 50.4, Written communications. Information included in your response that is considered sensitive or proprietary that you seek to have withheld from the public, must be marked in accordance with 10 CFR 2.390, Public inspections, exemptions, requests for withholding. Any information related to security should be submitted in accordance with 10 CFR 73.21, Protection of Safeguards Information: Performance Requirements. Following receipt of the additional information, we will continue our review of your renewal request.

T. Koeth If you have any questions, or need additional time to respond to this request, please contact Mr. Eben S. Allen at 301-415-4246, or by electronic mail at Eben.Allen@nrc.gov.

Sincerely,

/RA/

Cindy Montgomery, Project Manager Research and Test Reactors Licensing Branch Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-166

Enclosure:

Request for Additional Information cc: See next page

University of Maryland Docket No. 50-166 cc:

Director, Dept. of Natural Resources Power Plant Siting Program Energy & Coastal Zone Administration Tawes State Office Building Annapolis, MD 21401 Mr. Roland G. Fletcher, Program Manager IV Radiological Health Program Maryland Department of Environment 1800 Washington Blvd., Suite 750 Baltimore, MD 21230-1718 Mr. Vincent G. Adams Facility Coordinator Chemical and Nuclear Engineering Building 090 University of Maryland College Park, MD 20742 Mary J. Dorman Radiation Safety Officer Department of Environmental Safety 3115 Chesapeake Building 338 University of Maryland College Park, MD 20742 Professor Ray Phaneuf Department of Materials Science and Engineering Chemical and Nuclear Engineering Building 090 University of Maryland College Park, MD 20742-2115 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611

ML15219A471 concurrence via e-mail* NRR-088 OFFICE NRR/DPR/PRLB NRR/DPR/PRLB NRR/DPR/PRLB NRR/DPR/PRLB NRR/DPR/PRLB NAME EAllen ELee PBoyle* AAdams CMontgomery DATE 8/12/2015 8/14/2015 9/1/2015 9/10/2015 9/10/2015

OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION FOR THE RENEWAL OF FACILITY OPERATING LICENSE NO. R-70 THE MARYLAND UNIVERSITY TRAINING REACTOR DOCKET NO. 50-166 The U.S. Nuclear Regulatory Commission (NRC) is continuing its review of your application for renewal of Facility Operating License No. R-70, for the Maryland University Training Reactor (MUTR), dated May 12, 2000 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML052910399). During our review of supplemented information dated February 2, 2011 (ADAMS Accession No. ML110350175), NRC staff found it necessary to perform independent calculations to confirm the results in the MUTR Safety Analysis Report (SAR), as supplemented. Questions have arisen requiring additional information and clarification to support a departure from nucleate boiling ratio confirmation calculation.

1. Guidance in NUREG-1537, Part 2, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Standard Review Plan and Acceptance Criteria Section 4.6 provides that a reviewer should confirm that the thermal-hydraulic analyses for the reactor are complete and address all issues that affect key parameters (e.g., flow, temperature, pressure, power density, and peaking). MUTR SAR section 4.6 Thermal Hydraulic Design describes maximum fuel temperature with natural convection cooling.

However, independent confirmatory calculations cannot be completed because of incomplete or conflicting information in the SAR and thermal hydraulic analysis dated February 2, 2011.

Provide additional information to the specific parameters requested below or justify why they are not needed.

a. MUTR SAR Section 4.2.1 Reactor Fuel states MUTR TRIGA fuel is slightly smaller than standard TRIGA fuel. Clarify the General Atomics fuel element (FE) type used at the MUTR.

b. MUTR SAR Section 4.2.1.1 Fuel Moderator Elements describes the cladding outer diameter (35.8 millimeters), fuel meat outer diameter (34.798 millimeters), and zirconium rod (4.57 millimeters) used after fuel element hydrating. However, the thermal hydraulic analysis dated February 2, 2011, describes fuel meat outer diameter (34.823 millimeters), and zirconium rod diameter (5.715 millimeters). It appears the values conflict with one another. Design values (probably written in inches) are typically obtained from design drawings that indicate values accurate to three decimal places.

Provide a drawing of a typical four-rod fuel assembly as shown in Figure 4.1, Fuel-Moderator Element to clarify the correct fuel meat, cladding and zirconium rod dimensions.

c. MUTR SAR Section 4.0 Rector Description Figure 4.1 Fuel-Moderator Element displays the Stainless Steel Locking Plate; Four-Rod Fuel Cluster Bottom Adapter (Figure 4.4), and the Four-Rod Fuel Cluster Handle (Figure 4.6); however, there is insufficient detail for independent confirmation calculations.

Enclosure

i. Provide a plan view or engineering drawing for the Four-Rod Fuel Cluster Bottom Adapter that can be used to calculate the flow area and the hydraulic diameter.

ii. Provide a plan view, engineering drawing, or description of the top FE Stainless Steel Locking Plate.

iii. Provide a plan view or engineering drawing for a Four-Rod Fuel Cluster Handle that can be used to calculate the flow area and the hydraulic diameter.

d. The MUTR thermal hydraulic analysis dated February 2, 2011, provides power peaking values; however, these values appear to be developed from other TRIGA reactors. To complete independent confirmation calculations NRC staff require neutronic and thermal hydraulic analyses specific to the MUTR facility identifying hot fuel rod values. Due to the complexity of neutronic and thermal hydraulic analyses, provide an expected completion date of these analyses, or justify why they are not necessary. Include a description of identified millstones, the analysiss approach, and methodology.

e. MUTR SAR Section 1.5 Comparison With Similar Facilities explains the MUTR is a TRIGA conversion from an MTR-type reactor. MUTR SAR Section 4.0 Rector Description Figure 4.9 Core Layout and the thermal hydraulic analysis dated February 2, 2011, both show the reactor grid plate layout containing components of the reactor core. There is insufficient detail in these descriptions for independent confirmation calculations.

i. Provide the bottom elevation of active FEs measured from the bottom of the reactor tank.

ii. Clarify whether the grid plate locations that do not contain fuel assemblies are open or closed to flow during normal operation.

iii. Clarify whether there are any other penetrations allowing the flow of water through the core other than the FE adaptor in the grid plate. If so, provide the dimensions or corresponding flow area(s).

iv. Confirm the grid spacing dimensions.

f. MUTR SAR Section 4.1 Summary Description states the core is cooled by natural convection; however, MUTR SAR Section 1.3.5 Cooling System states the coolant flow rate is 120 gallons per minute and the thermal hydraulic analysis dated February 2, 2011, assumes a flow rate of 120 gallons per minute, entering at the bottom of reactor core. Clarify the typical core flow rate at full power.