ML071500054
| ML071500054 | |
| Person / Time | |
|---|---|
| Site: | Purdue University |
| Issue date: | 05/25/2007 |
| From: | Joel Jenkins Purdue University |
| To: | Mendonca M Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML071500054 (6) | |
Text
PURDUE U N I V E R S I T Y SCHOOL OF NUCLEAR ENGINEERING 25 May 2007 Document Control Desk ATTN: Mr. Marvin Mendonca U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738
SUBJECT:
Application for Amendment to License R-87, Docket No. 50-182, to Increase the Possession Limits for Uranium-235 Regarding the above mentioned license, the Purdue University Research Reactor (PUR-1) is currently licensed to "receive, possess and use up to three (3) kilograms of Uranium-235 contained in uranium enriched in the isotope Uranium-235" in connection with the operation of the facility. Currently, PUR-1 is working with the U.S. Department of Energy (DOE), DOE contractors and the Nuclear Regulatory Commission (NRC) to convert the reactor from Highly Enriched Uranium (HEU) fuel to Low Enriched Uranium (LEU) fuel in support of the Global Threat Reduction Initiative.
Due to this planned reactor fuel conversion, PUR-1 will be making a spent fuel shipment, and receiving a fresh LEU fuel shipment to complete the evolution. In order to minimize shutdown time of the facility, and to perform the required tasks for conversion in a timely fashion, PUR-1 must increase its possession limits of U-235. PUR-1 is the only licensed reactor in the state of Indiana, and its extended shutdown will adversely impact the students and academic researchers at Purdue University.
Furthermore, the limit increase allows PUR-1 to receive the new fuel while still maintaining possession of the existing HEU core until it can be shipped to a DOE facility for storage. This will allow PUR-1 to perform its quality assurance verifications of the new fuel plates, and quality assurance verifications during the assembly of the new LEU elements prior to assembly of the LEU core. It will also allow for timely restart so as to minimize the impact on the users of the facility. In order to avoid this prolonged reactor shutdown, a period will exist in which PUR-1 will need to possess a quantity of U-235 in excess of the current licensed maximum of three (3) kilograms.
School of Nuclear Engineering Nuclear Engineering Building o 400 Central Drive o West Lafayette, IN 47907-2017 (765) 494-5739 o Fax: (765) 494-9570 o https://engineering.purdue.edu/NE
PUR-1 Possession Limit Request License R-87, Docket 50-182 Page 2 of 2 The following table provides the current and anticipated on-site gram inventory of U-235 throughout the conversion evolution:
Transaction Timeline Transaction, g U-235 On-Site Inventory, g U-235 Current 2050 Fuel Receipt +3800 5850 Fuel Shipment -2047 3803 Includes U-235 in Fission Chamber, which is not shipping out.
To facilitate this important conversion, the Purdue University Research Reactor requests a temporary amendment to the Facility Operating License No. R-87, Amendment No. 10, Section 2, Part B.(2), allowing the possession limits to be increased from three (3) kilograms to seven (7) kilograms of Uranium-235. A limit of seven (7) kilograms is proposed to cover any potential uncertainties in the total mass of U-235 in the PUR-1 inventory. Once the shipment of the HEU core offsite is complete, PUR-1 proposes that the possession limit be lowered to the new license limit proposed in the conversion proposal (ML070920272) of 3900 grams (3.9 kilograms).
Please see the attachment to this document for the safety analysis for this proposal. Should you have any questions, or require further information, please contact Mr. Jere Jenkins, at 765.496.3573, or jere@purdue.edu.
Under penalty of perjury, I declare this to be true and correct to the best of my knowledge.
Director of Radiation Laboratories Purdue University Nuclear Engineering Cc: Alexander Adams, NRC Project Manager Dan Hughes, NRC Project Manager
Enclosures:
As stated.
SAFETY ANALYSIS SUPPORTING REQUEST FOR POSSESSION LIMIT CHANGES TO ALLOW CONVERSION FROM HIGH-ENRICHED TO LOW ENRICHED URANIUM FUEL PURDUE UNIVERSITY RESEARCH REACTOR LICENSE NO. R-87 DOCKET NO. 50-182 1 INTRODUCTION The Purdue University Research Reactor (PUR-1) is requesting a change to possession limits for the isotope Uranium-235 to support the conversion from Highly Enriched Uranium (HEU) to Low Enriched Uranium (LEU) in accordance with 10 CFR 50.64 with the support of the U.S. Department of Energy, as part of its Global Threat Reduction Initiative. In order to allow for the timely conversion of PUR-1, the possession limit increase will allow PUR-1 staff to perform all necessary functions for Quality Assurance in receipt of the new LEU fuel, and Quality Assurance in assembly of the new reactor fuel elements, and reduce to the extent possible the shutdown time required for the conversion evolution, thereby minimizing the impact on the users of the facility, the students and faculty of Purdue University.
2 SAFETY Maintaining security by procedure, racks specifically constructed for the purpose of storage of the plates will contain each bundle. A criticality analysis of the storage facility was performed with MCNP. The model is shown in Figure 1.
Figure 1: MCNP model of dry storage facility.
Analysis Safety Analysis Limit Safety 1/3 25 May07 PUR-1 Possession Limit PUR-1 Possession 1/3 25 May 07
With all of the plates moved to that new location, the calculated eigenvalue of the storage rack is 0.015+/-0.0003. Should the storage flood with water, the eigenvalue becomes 0.26+/-0.004. In both of these conditions, the TS limit of keff<0. 8 is met. Parametric analyses were performed with spacing of the plates within the tubes, and the above listed cases are the worst case. All movement of fuel will be performed under the direction of licensed senior reactor operators.
After pre-assembly, the fuel elements will be returned to dry storage. The use of the in-pool storage racks was modeled, though, as a limiting case, since the in-pool storage racks place the assemblies in a configuration similar to the dry storage facility, and it is already flooded. An MCNP model of the in-pool storage racks was constructed. Two cases for the LEU fuel were examined. One case was run with standard LEU assemblies in all of the 18 positions (which is not possible with the anticipated LEU inventory, but was run as a limiting case), and no credit was taken for the 1/4" BORAL plate between the two rows. This first case had a calculated eigenvalue of 0.7660+/-0.0046. The second case was modeled with the 1/4" BORAL plate with a boron density of 23.8E21 atoms/co, and 16 standard assemblies with 14 fuel plates in each. The eigenvalue for this calculation was determined to be 0.3319 +/-0.00178. Both of these bracketing cases are below the TS 5.3 limit of 0.8, thus TS 5.3 will be met. The geometry of the model is shown in Figure 2 below.
Figure 2: Model of the in-pool fuel storage racks.
3 OTHER LICENSE CONSIDERATIONS No changes to the Technical Specifications are required for this request, as no LEU fuel will be loaded into the core until an NRC Order to Convert is received by the licensee. The only work to be done with the LEU fuel will involve receipt inspection of each LEU plate, and pre-assembly of LEU reactor fuel elements in preparation for eventual core loading and approach to critical, with no core insertion.
4 CONCLUSIONS All work will be performed in accordance to appropriate NRC regulations and license requirements. The LEU fuel will not be used in the core until an order to PUR-1 Possession Limit Safety Analysis 2/3 25 May 07
convert is received from the NRC. The only work done with the LEU fuel will be receipt inspection and quality assurance, and pre-assembly of the LEU plates into fuel elements, without insertion into the core.
Analysis 3/3 25 May 07 PUR-1 Possession PUR-1 Safety Analysis Limit Safety Possession Limit 3/3 25 May 07
Department of Energy Idaho Operations Office 1955 Fremont Avenue S Idaho Falls, ID 83415 February 15, 2007 Jere H. Jenkins Director of Radiation Laboratories Purdue School of Nuclear Engineering Nuclear Engineering Building 400 Center Drive West Lafayette, IN 47907-2017
SUBJECT:
Material Possession Limits at Purdue University (TD&D-NS-07-004)
Dear Mr. Jenkins:
As part of the U. S. Department of Energy's (DOE) efforts to convert the Purdue PUR-1 reactor from High Enriched Uranium (HEU) fuel to Low Enriched Uranium (LEU), a logistical issue has been identified that requires your timely attention. The issue is that the new fuel plates and new fuel containers will likely be fabricated at separate locations. If this occurs, the logistics will require the fuel plates and fuel containers be delivered to Purdue and then be assembled at a Purdue facility. This precipitates the need for the new reactor fuel to be delivered to your facility before the spent fuel can be shipped out later in the year.
We expect that these logistics will require the issuance of an Order from the Nuclear Regulatory Commission to allow you to increase your possession limits. This increase may only be necessary until the spent fuel is shipped from your facility.
Please review the imp act of this situation on your prograrn and take the steps necessary to allow the fuel to be received, stored, and assembled before the spent fuel is shipped. As always, we will help as necessary to ensure your success with this task. If you have questions please call Carl Friesen at (208)526-1765.
Sincerely, Donald W. Macdonald, Team Lead National Security Programs