ML23003A046

Response to Request for Reviewing a Position Paper from Nuclear Fuel Services, Inc. Related to Applicability of 10 CFR 71.15(C) to Shipment(S)

ML23003A046
Person / Time
Site:	Erwin
Issue date:	03/29/2023
From:	Shana Helton Division of Fuel Management
To:	Knowles T Nuclear Fuel Services
Garcia-Santos N
Shared Package
ML23003A040	List: ML23003A046
References
CAC 001029, EPID L-2022-LLL-0017
Download: ML23003A046 (3)

Text

Tim Knowles, Director Safety and Safeguards Nuclear Fuel Services, Inc.

1205 Barnner Hill Road Erwin, TN 37650

SUBJECT:

REQUEST FOR REVIEWING A POSITION PAPER FROM NUCLEAR FUEL SERVICES, INC. RELATED TO APPLICABILITY OF 10 CFR 71.15(C) TO SHIPMENT(S)

Dear Tim Knowles:

This letter responds to your request dated September 16, 2022, (Agencywide Documents Access and Management System [ADAMS] Accession No. ML22285A146), for the U.S. Nuclear Regulatory Commission (NRC) to review and concur on the document titled Position Paper for Compliant Handling, Shipping, and Disposal of Low-Level Radioactive Waste Containing Fissile Material per the Exemption in 10 CFR 71.15 (hereafter, position paper). In this letter the NRC staff (hereafter, the staff) provides its views on Nuclear Fuel Services Inc.s (hereafter, the licensee) discussion on the position paper of regulatory applicability of Title 10 of the Code of Federal Regulations (10 CFR) 71.15(c)(1) and concludes that the shipping configuration NFS describes does not meet the requirements of this regulation.

In its position paper, the licensee describes a transportation configuration of waste material containing uranium-235 (235U) that the licensee believes meets the fissile exemption requirements of 10 CFR 71.15(c)(1). This regulation allows low concentrations of fissile material commingled with solid nonfissile material to be exempted from the fissile material transportation requirements provided that:

(i) There is at least 2,000 grams of solid material nonfissile material for every gram of fissile material, and (ii) There is no more than 180 grams of fissile material distributed within 360 kg of contiguous nonfissile material.

The configuration that the licensee describes consists of radioactive material containing 235U (fissile material) placed in plastic bottles or liners and subsequently in 55-gallon drums filled with sand in a mass sufficient to meet the 2,000:1 of nonfissile-to-fissile mass ratio required by 10 CFR 71.15(c)(1)(i). The licensee stated that it would also need to control the mass of fissile material per drum to meet the mass distribution criterion of 10 CFR 71.15(c)(1)(ii) (no more than 180 grams fissile material distributed within 360 kilograms of contiguous nonfissile material).

March 29, 2023

T. Knowles 2

The licensee noted in its position paper that it believes the transport configuration described meets the requirements of 10 CFR 71.15(c), since the fissile material is commingled with nonfissile material in the required ratio per 10 CFR 71.15(c)(1)(i), and the distribution requirement of 10 CFR 71.15(c)(1)(ii) is met. In section 7 of the position paper, the licensee further notes that the calculations referenced in NUREG/CR-7239 ORNL/TM-2013/57, Review of Exemptions and General Licensees for fissile Material in 10 CFR 71, (ML18052A520)

(hereafter, NUREG/CR-7239) allow for non-homogeneity/redistribution while remaining compliant with the safety basis of the regulation. The licensee also notes that the calculations performed to support the 10 CFR 71.15(c) fissile exemption in NUREG/CR-7239 do not carry an expectation the waste matrix is homogeneous.

The staff notes that NUREG/CR-7239 provides a discussion of the intent of the fissile exemptions in 10 CFR 71.15, and clearly states for 10 CFR 71.15(c) in section 4.1.3 that:

The intent is to have package contents that have an essentially homogeneous mixture of fissile and nonfissile material.

the fissile material must be distributed within contiguous nonfissile material, which will ensure the fissile material will not form any heterogeneous arrangements within the waste matrix during normal conditions of transport and hypothetical accident conditions.

The licensee noted that the staff performed calculations evaluating potential heterogeneous configurations of fissile material commingled with nonfissile material. However, the staff performed these calculations to ensure that essentially homogeneous packaged material, which may have concentration variations introduced during normal conditions of transport and hypothetical accident conditions (e.g., due to leaching, settling, impacts, fire, etc.) would remain subcritical in infinite quantities with the distribution requirement of 10 CFR 71.15(c)(1)(ii) (see the discussion of large rail cars containing homogenized distributions of fissile material within a nonfissile waste matrix in the 10 CFR Part 71 2004 Final Rule (69 Federal Register 3698, 3749)). The licensees described transportation configuration is heterogeneous as packaged, and as discussed below, could have non-fissile mass removed from the packaging configuration during normal conditions of transport and hypothetical accident conditions.

The staff notes that for the described fissile material configuration, the plastic bottles containing fissile material are easily separable from the nonfissile backfill material (i.e., sand) under normal conditions of transport or hypothetical accident conditions, where material may be released from the package. Separated plastic bottles containing fissile material do not provide assurance of criticality safety in an optimum moderation accident condition, as required by 10 CFR 71.55(e)(1) and (2), and 10 CFR 71.59(a)(2) (including melting of plastic bottles in a fire, and the addition of unlimited quantities of water). This is especially true considering that there is no package accumulation control for fissile exempt packages, and criticality calculations supporting fissile exemptions, therefore, consider infinite media.

T. Knowles 3

Accordingly, the staff disagrees with the licensee that the shipping configuration described in the position paper meets the fissile material exemption regulation in 10 CFR 71.15(c)(1).

Additionally, NUREG/CR-7239 describes essentially homogeneous material configurations that meet the requirements in 10 CFR 72.15 on exemption from classification as fissile material.

The staff is available to meet to discuss this letter. If you have any questions, please contact Norma Garcia Santos of my staff at Norma.GarciaSantos@nrc.gov.

Sincerely, Shana Helton, Director Division of Fuel Management Office of Nuclear Material Safety and Safeguards Docket No.70-143 CAC No. 001029 EPID No. L-2022-LLL-0017 Signed by Helton, Shana on 03/29/23