ML23310A112

Aerotest - Letter, License Amendment 7 and SE Approving the Decommissioning Plan for the Radiography and Research Reactor

ML23310A112
Person / Time
Site:	Aerotest
Issue date:	03/06/2024
From:	John Marshall Division of Decommissioning, Uranium Recovery and Waste Programs
To:	Slaughter D Aerotest
Shared Package
ML23310A104:ml23310a104	List: ML23310A112 ML23310A114
References
EPID L-2021-LLN-0004
Download: ML23310A112 (44)

Text

Dr. David M. Slaughter, President and Reactor Administrator Aerotest Operations, Inc.

3455 Fostoria Way San Ramon, CA 94583

SUBJECT:

AEROTEST OPERATIONS, INC., ISSUANCE OF LICENSE AMENDMENT NO. 7 TO FACILITY OPERATING LICENSE NO. R-98 FOR THE AEROTEST RADIOGRAPHY AND RESEARCH REACTOR (EPID NO. L-2021-LLN-0004)

Dear Dr. Slaughter:

The U.S. Nuclear Regulatory Commission (NRC) has issued the enclosed Amendment No. 7 to Facility Operating License No. R-98 for the Aerotest Operations, Inc. (Aerotest or the licensee),

Aerotest Radiography and Research Reactor (ARRR). The amendment consists of changes to the facility operating license in response to your application dated July 20, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21230A304), as supplemented by letters dated January 20, 2022, July 21, 2022, and November 16, 2022 (ML22025A200, ML22215A152, and ML22340A004, respectively), to approve the Decommissioning Plan (DP) for the ARRR.

Pursuant to Section 20.1405, Public notification and public participation, of Title 10 of the Code of Federal Regulations (10 CFR) and Paragraph (b)(5) of 10 CFR 50.82, Termination of license, the NRC published a notice and solicitation of comments for this DP in the Federal Register (FR) on July 28, 2023 (88 FR 48919). The NRC also conducted a safety and technical evaluation of the proposed DP. Based on these actions, the NRC has concluded that the ARRR DP demonstrates that the proposed decommissioning plan will be performed in accordance with the Commissions regulations and will not be inimical to the common defense and security or to the health and safety of the public. Therefore, the Commission approves the application and amends Facility License No. R-98 to reflect the decommissioning status.

The amendment incorporates the DP into the license as a supplement to Aerotests Safety Analysis report, pursuant to 10 CFR 50.82(b)(5). The amendment also adds conditions on how the DP can be changed after this approval and a condition to update the DP before the start of major dismantlement activities in accordance with 10 CFR 50.82(b)(2). No changes are necessary to the other Possession-Only License Conditions and the Technical Specifications, both of which remain in effect. The approved DP is subject to such conditions and limitations as the Commission deems appropriate and necessary and as provided in the enclosed Safety Evaluation Report (SER). The SER also identifies areas of the DP that will need to be updated and approved before the start of major dismantlement activities.

A Notice of Issuance of this amendment will be published in the Federal Register. March 6, 2024 Dr. Slaughter If you have any questions, please contact Jack Parrott at 301-415-6634, or by electronic mail at Jack.Parrott@nrc.gov.

Sincerely, Jane E. Marshall, Director Division of Decommissioning, Uranium Recovery, and Waste Programs Office of Nuclear Material Safety and Safeguards Docket No. 50-228 License No. R-98

Enclosures:

1. Amendment No. 7 to Facility Operating License No. R-98

2. Safety Evaluation Report cc: California Energy Commission 1516 Ninth Street, MS-34 Sacramento, CA 95814 Radiologic Health Branch P.O. Box 997414, MS 7610 Sacramento, CA 95899-7414 Test, Research and Training Reactor Newsletter Attention: Ms. Amber Johnson Dept of Materials Science and Engineering University of Maryland 4418 Stadium Drive College Park, MD 20742-2115 Aerotest Operations, Inc.

3455 Fostoria Way San Ramon, CA 94583 Signed by Marshall, Jane on 03/06/24

AEROTEST OPERATIONS, INC

DOCKET NO. 50-228

AEROTEST RADIOGRAPHY AND RESEARCH REACTOR

AMENDMENT TO FACILITY OPERATING LICENSE

Amendment No. 7 License No. R-98

1. The U.S. Nuclear Regulatory Commission (NRC or the Commission) has found that:

A. The application for an amendment to Facility Operating License No. R--98, filed by Aerotest Operations, Inc. (the licensee), on July 20, 2021, as supplemented on January 20, 2022, July 21, 2022, and November 16, 2022, complies, as evaluated in the NRC staffs safety evaluation dated March 6, 2024, with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I;

B. The facility will be possessed in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission;

C. There is reasonable assurance that (i) the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) such activities will be conducted in compliance with the regulations of the Commission set forth in 10 CFR Chapter I;

D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public;

E. This amendment is issued in accordance with 10 CFR Part 51, Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions, of the Commission regulations and all applicable requirements have been satisfied; and

F. Pursuant to the requirements in 10 CFR 20.1405, Public notification and public participation, the NRC staff provided notification of the availability of, and solicited comments on, the Aerotest Radiography and Research Reactor Decommissioning Plan from local and state governments in the vicinity of the site, as well as from potentially affected parties and the public. No Indian Nation or other indigenous people that have treaty or statutory rights that could be affected by the decommissioning of the ARRR facility could be identified. Prior notice of this amendment was not required by 10 CFR 2.105, Notice of Proposed Action, and publication of a notice for this amendment is not required by 10 CFR 2.106, Notice of Issuance.

Enclosure 1

2. Accordingly, the license is hereby amended by the addition of License Condition 2.F. to read as follows:

F. Decommissioning The licensee shall implement and maintain in effect all provisions of the approved Decommissioning Plan for the Aerotest Radiography and Research Reactor, dated July 20, 2021, as supplemented on January 20, 2022, July 21, 2022, and November 16, 2022 (hereinafter the DP), which authorizes inclusion of the DP as a supplement to the Safety Analysis report pursuant to 10 CFR 50.82(b), and is subject to and amended by the following stipulations:

(1)The licensee may make changes to the DP without prior NRC approval provided the proposed changes do not meet any of the following criteria:

a)Require Commission approval under 10 CFR 50.59, Changes, tests, and experiments.

b)Result in the potential for significant environmental impacts that have not previously been reviewed.

c)Detract or negate the reasonable assurance that adequate funds will be available for decommissioning.

(2)This DP is approved under the regulation in 10 CFR 50.82(b)(2) that allows for a DP, in which the major dismantlement activities are delayed by first placing the facility in storage, to be less detailed. Therefore, an updated detailed DP shall be submitted and approved prior to the start of major dismantlement activities. The updated DP shall contain more detailed information on the remaining site characterization, dismantlement, and remediation activities, as well as the final status survey plan, for NRC review and approval prior to conducting final status surveys for license termination.

Approval of this less detailed DP is not binding on the NRCs determination of the specific adequacy of the updated detailed ARRR DP.

3. This license amendment is effective as of the date of its issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Jane E. Marshall, Director Division of Decommissioning, Uranium Recovery, and Waste Programs, Office of Nuclear Material Safety and Safeguards Signed by Marshall, Jane on 03/06/24

Attachments:

1. Changes to Renewed Facility Operating License No. R-98

Date of Issuance: March 6, 2024 SAFETY EVALUATION REPORT BY THE

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

RELATED TO AMENDMENT NO. 7 TO

FACILITY OPERATING LICENSE NO. R-98

AEROTEST OPERATIONS, INC.

APPROVAL OF THE DECOMMISSIONING PLAN FOR THE

AEROTEST RADIOGRAPHY AND RESEARCH REACTOR

DOCKET NO. 50-228

1.0 INTRODUCTION

The Aerotest Radiography and Research Reactor (ARRR) was licensed to operate pursuant to Section 104c of the Atomic Energy Act of 1954, as amended, and under Paragraph (c) of Section 50.21, Class 104 licenses; for medical therapy and research and development facilities, of Title 10 of the Code of Federal Regulations (10 CFR). The ARRR started operation in 1964 and ceased operation in 2010. The license was modified on December 6, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21242A463) to remove the authority to operate the ARRR, to authorize possession-only of the reactor and fuel, and to remove operational requirements not needed for the possession-only status.

By application dated July 20, 2021 (ML21230A304), as supplemented by letters dated January 20, 2022, July 21, 2022, and November 16, 2022 (ML22025A200, ML22215A152, and ML22340A004, respectively), Aerotest Operations, Inc. (Aerotest or the licensee) submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request for changes to Facility Operating License No. R-98 for the ARRR. The proposed changes would amend the license (License Amendment No. 7) to approve the Decommissioning Plan (DP) for the ARRR, which was submitted an accordance with Paragraph (b) of 10 CFR 50.82, Termination of license, for the decommissioning of non-power reactors. The July 20, 2021, submittal included the proposed DP as required under 10 CFR 50.82(b)(1). The January 20, 2022, submittal included an application for termination of the ARRR Facility Operating License No. R-98, which is also required by 10 CFR 50.82(b)(1). The July 21, 2022, and November 16, 2022, submittals supplied additional information requested by the NRC in a letter dated June 28, 2022 (ML22152A252).

The ARRR ceased operation on October 15, 2010, and Aerotest declared the ARRR to be permanently shut down as of December 6, 2018. A possession-only license (POL) was issued for the ARRR in December 2021 that, in part, evaluated the licensee's, safety systems, Certified Fuel Handler Program, security plans, emergency plans, and method of fuel storage and configuration for long-term storage suitability. Pursuant to 10 CFR 50.82(b), Aerotest intends to proceed with decommissioning and termination of the ARRR reactor license. As described in

Enclosure 2

the proposed DP, the licensee intends to keep the facility in a safe storage condition consistent with the requirements of the POL until such time as the fuel is removed from the site. After fuel removal Aerotest is required to file updated, and more detailed, plans for decommissioning that must be submitted by license amendment and approved by the NRC, pursuant to 10 CFR 50.82(b)(2), prior to the start of active decommissioning. At that point the licensee would undertake dismantlement, waste disposal, decontamination, and survey activities so that the ARRR license can be terminated, and the site released for unrestricted use.

The NRC noticed the ARRR DP in the Federal Register on July 28, 2023, and provided opportunity for interested persons to provide comments (88 FR 48919). In accordance with 10 CFR 20.1405, Public notification and public participation, the notice solicited comments from individuals and local and state governments in the vicinity of the site, as well as any Indian Nation or other indigenous people that have treaty or statutory rights that could be affected by the decommissioning. Further, in accordance with 10 CFR 50.82(b)(5), the notice informed interested persons of the Commission's intent to approve the plan by amendment, subject to such conditions and limitations as the Commission deems appropriate and necessary, if the plan demonstrates that decommissioning will be performed in accordance with the Commission regulations and will not be inimical to the common defense and security or to the health and safety of the public. No comments from the public, local governments, or the State of California were received. No Indian Nation or other indigenous people that have treaty or statutory rights that could be affected by the decommissioning of the ARRR facility could be identified.

This Safety Evaluation Report (SER) summarizes the NRC staffs safety review of the licensees proposed ARRR license amendment and DP. Based on the results of this review, as described below, the NRC staff approves the proposed license amendment and DP for the ARRR.

2.0 REGULATORY EVALUATION

The regulations in 10 CFR 50.82(b)(4) contains the requirements for the contents of DPs for non-power reactors. This regulation requires that the proposed DP include the following items:

• The choice of the alternative for decommissioning with a description of activities involved;

• A description of the controls and limits on procedures and equipment to protect occupational workers and public health and safety from ionizing radiation;

• A description of the planned final status survey (FSS);

• An updated cost estimate for the chosen alternative for decommissioning, a comparison of that estimate with present funds set aside for decommissioning, and a plan for assuring the availability of adequate funds to complete decommissioning; and

• A description of the quality assurance (QA) provisions, physical security plan provisions, and technical specifications (TS) in place during decommissioning.

However, 10 CFR 50.82(b)(2) states that for decommissioning plans in which the major dismantlement activities are delayed by first placing the facility in storage, planning for these delayed activities may be less detailed, and that updated detailed plans must be submitted and approved prior to the start of the major dismantlement activities. In these instances, pursuant to 10 CFR 50.82(b)(3), the licensee must provide additional information regarding financial

assurance that sufficient funds will be available to complete the decommissioning activities at the end of the storage or surveillance period.

The NRC conducted its review of the ARRR DP submitted by Aerotest in accordance with 10 CFR 50.82(b)(2) and 10 CFR 50.82(b)(5) to determine whether the preferred decommissioning alternative, including the period of safe storage and deferral of active dismantlement and decontamination until after removal of the fuel from the site, would be performed in accordance with applicable regulations and would not be inimical to the common defense and security or to the health and safety of the public. 10 CFR 50.82(b)(5) states that, if the NRC finds that these criteria are met, after notice to interested persons it will approve, by amendment, the DP, subject to such conditions and limitations as the Commission deems appropriate and necessary. The DP will be included as a supplement to the licensees Safety Analysis report for the decommissioning facility.

After fuel removal and prior to the start of active decommissioning, Aerotest is required by the regulation in 10 CFR 50.82(b)(2) to file an updated detailed DP for NRC review and approval. At that point the licensee would undertake dismantlement, waste disposal, decontamination, and FSS activities so that the license can be terminated, and the site released for unrestricted use in accordance with the criteria in 10 CFR 20.1402, Radiological criteria for unrestricted use.

Upon future approval of a detailed DP for ARRR, 10 CFR 50.82(b)(6) provides that the NRC will terminate the license if it determines that the decommissioning has been performed in accordance with the approved DP and that the FSS and associated documentation demonstrate that the facility and site are suitable for release in accordance with the criteria for decommissioning in 10 CFR Part 20, Standards for Protection Against Radiation, Subpart E, Radiological Criteria for License Termination.

The NRC staff conducted its review of ARRRs DP using the guidance: NUREG-1537, Part 1, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors:

Format and Content (ML042430055), Chapter 17, Decommissioning and Possession-Only License Amendments; NUREG-1537, Part 2, Standard Review Plan and Acceptance Criteria (ML042430048), Chapter 17, Decommissioning and Possession-Only License Amendments, and Appendix 17.1, NRC Review of Decommissioning Plans for Non-Power Reactors; and NUREG-1757, Volume 2, Consolidated Decommissioning Guidance: Characterization, Survey, and Determination of Radiological Criteria, Revision 2 (ML22194A859). NUREG-1537 provides guidance to the NRC staff for performing reviews of possession-only license amendment requests for non-power reactors, including the review of the decommissioning plan.

NUREG-1757 provides guidance for the review of facility radiological status and determination of appropriate release criteria.

3.0 TECHNICAL EVALUATION

3.1 Background

The ARRR is a 250 kilowatt-thermal Training, Research, Isotope, General Atomics (TRIGA) research reactor that was used primarily to perform neutron radiography on various industrial components and materials. The ARRR operated from 1965 until it was shut down on October 15, 2010, as documented in NRC Non-Routine Inspection Report No. 50-228/2010-203, dated December 6, 2010 (ML103340011). All fuel was removed from the reactor core in 2012, as documented in NRC Non-Routine Inspection Report No. 50-228/2012-204, dated August 14, 2012 (ML12213A001). The fuel is currently in wet storage in the reactor pool. Aerotest continues to own, possess, and store TRIGA fuel elements

at ARRR under Facility Operating License No. R-98. This fuel will be retained at the ARRR site until such time as the U.S. Department of Energy (DOE) removes it from the facility pursuant to DOE Contract DE-CR01-83NE44484.

As the fuel remains in wet storage at the ARRR facility and is preventing dismantlement and decommissioning activities from occurring, Aerotest is proposing to delay the major dismantlement and decontamination activities associated with decommissioning until after the TRIGA fuel elements are removed from the site. Because of this delay in dismantlement of the facility, the planning for these delayed activities described in the initial ARRR DP can be less detailed than the final DP, in accordance with 10 CFR 50.82(b)(2). The current Aerotest license amendment request and DP were reviewed by the NRC staff in consideration of this safe storage status and with the understanding that updated detailed plans must be submitted and approved by the NRC prior to the start of active decommissioning activities.

3.2 Decommissioning Alternatives

The overall objective of the ARRR decommissioning activities is the regulatory release of the property and buildings for unrestricted use. Prior to implementing the decommissioning actions described in the DP, Aerotest states that the ARRR facility will have been cleared of all extraneous fixtures, equipment, and materials. To the extent practical, the facilities will have been decontaminated to meet the site criteria for unrestricted access, radioactive waste will have been removed from the site, and secondary support systems outside the reactor building that are no longer needed will have been removed.

Section 4.1, Decommissioning Activities, of the ARRR DP outlined the proposed decommissioning pathway and considered three possible scenarios. As noted, the licensee intends to keep the facility in a safe storage condition until such time as the fuel is removed from the site. Section 4.1 of the ARRR DP states that in safe storage, the ARRR would be placed and maintained in a condition that allows it to be safely stored and subsequently decontaminated to meet the NRC and State of California radiological criteria permitting unrestricted release of the property. Implementation of the proposed safe storage decommissioning pathway would include retention of fuel on site. Section 4.1 of the ARRR DP states that this could be accomplished by using one (or a combination) of three scenarios:

(1) storing the fuel in the pool covered with water where it is currently located, (2) removal of the reactor fuel from the pool to an onsite dry fuel storage location, or (3) maintain the fuel in the current pool location but under dry conditions. Once DOE has taken the fuel offsite, the facility would be decontaminated and dismantled (i.e., active decommissioning), including performance of the FSS, release of the site for unrestricted use, and termination of the ARRR license.

Although the ARRR DP does not indicate which of the three safe storage scenarios for fuel Aerotest will utilize at this point in the overall decommissioning process, the NRC staff notes that the licensee cannot currently implement dry storage of fuel in the reactor core tank, Scenario 3, because ARRR TS 4.1 requires at least 16 feet of water depth above the top of the core structure, which is well above the storage racks in the tank. Scenario 2 is infeasible without a license amendment because, while ARRR possesses six fuel storage pits each capable of storing 19 fuel elements, storage of fuel in the fuel storage pits is limited to 19 fuel elements in total pursuant to ARRR TS 11.1. A license amendment would be required to make changes to either of these TS requirements, which would prompt an NRC evaluation of the acceptability of storing fuel under Scenario 2 or Scenario 3 at the ARRR facility. Under either Scenario 2 or Scenario 3, major dismantlement activities would continue to be delayed. Under Scenario 2, even if there is enough licensed storage in the fuel storage pits to store all of the remaining fuel, these fuel storage pits are located in the reactor building and would likely prevent major

dismantlement activities. Under Scenario 3, the fuel would remain in the pool but in dry conditions and prevent dismantlement of the reactor unit as the fuel would be located directly in the reactor unit. Additional considerations related to fuel removal and storage are discussed in the response to Question 9 in the Aerotest letter dated July 21, 2022.

3.2.1 Conclusion

The NRC staff reviewed the licensees chosen method for decommissioning - a period of safe storage with fuel stored in the reactor building followed by updated and approved detailed decommissioning plans, then active decommissioning, decontamination, and dismantlement once the fuel has been permanently removed from the site - and concludes that this choice satisfies the requirements of 10 CFR 50.82(b)(4)(i). This choice is acceptable because, while it provides for completion of decommissioning with a significant delay from the original shutdown date for the ARRR, the delay necessary to protect the public health and safety because of the unavailability of waste disposal capacity for the ARRR fuel. Based on information from in the DP, the facility will be maintained in a safe and stable condition during the storage period, and prompt dismantlement and decontamination is expected to occur after the fuel is removed from the site and an updated detailed DP is approved by the NRC.

The NRC staff notes that there is a statement in Section 4.1 of the ARRR DP, in relation to release of the site for unrestricted use, that includes a possibility of burying at location low-level radioactive contaminated concrete that may exist, which surrounds the aluminum tank of the ARRR reactor. If this path forward is considered when the ARRR facility enters active decommissioning in the future, the NRC staff would need substantial additional detail to be provided in the updated ARRR DP related to this potential for onsite low-level radioactive waste disposal. Onsite waste disposal includes a different set of considerations than evaluating the residual radioactivity remaining onsite, as a result of decommissioning activities, and this type of disposal activity would need to be reviewed and approved by the NRC in advance of the action (see 10 CFR 20.2002, Method for obtaining approval of proposed disposal procedures).

3.3 Facility Radiological Status

3.3.1 Facility Description and Operating History

According to Section 4.2.1, Facility Operating History, of the ARRR DP, the reactor achieved initial criticality on July 9, 1965, with a licensed steady state thermal power limit of 250 kilowatts and provided a neutron source for various research and development projects, mainly neutron radiology, until reactor operations permanently ceased on October 15, 2010. The facility consists of a reactor building with a high bay section, control room, offices, bathrooms, change facilities, a lunchroom/conference room, machine shop, small laboratories and storage areas, including a waste storage room. The reactor building footprint is about 3,200 square feet with two floor levels. The total footprint for all buildings at the ARRR is 9,250 square feet. As previously noted, Aerotest states that fuel is currently onsite and will remain at the ARRR facility until its removal and transportation from the site by the DOE.

Section 4.2.1 of the ARRR DP discusses the potential sources of radiological contamination onsite based on historical operating occurrences. Specifically, the licensee noted that there were no instances of releases of radioactive material with activity levels greater than the public dose limits (in accordance with 10 CFR Part 20) for air or water during operation. There were no instances of surface water flooding at the site that might have contributed to an uncontrolled release of radioactive water. In addition, no gaseous fission products were recorded or detected

during operation of the ARRR. There was a single known instance of a leaking fuel element reported during operation of the ARRR, which was located and removed from the reactor core in November 1965. The ruptured fuel element was immediately shipped offsite for disposal.

However, Aerotest noted that the current presence of low levels of fission products such as Cesium-137 (Cs-137) in the ARRR pool water demineralizer system indicates there may be leaks from additional fuel elements. Additional information on the evaluation, disposition, and continued monitoring of leaking fuel elements can be found in the SER for the ARRR possession-only license amendment dated December 6, 2021.

3.3.2 Current Radiological Status

The ARRR DP included information from a Site Characterization Survey Report, dated October 12, 2011 (ML22340A017), which was performed by a contractor, EnergySolutions, and concluded that only minor quantities of residual radioactivity or radioactive contamination are present at the site. The information from the surveys indicates that the radioactive portions of the facility are primarily confined to the radioactive waste room and the reactor pool. The NRC staff note that this characterization report does not address potential contamination on the inside surfaces of the reactor pool originating from fuel element leaks. This should be addressed after fuel removal and dewatering of the reactor pool. The characterization information gathered will be used to develop the necessary decommissioning work evolutions, appropriate hazard controls, and estimated waste volumes to support the decommissioning plans described in the more detailed ARRR DP. In addition, the data collected in the report will contribute to estimates of radiological and mixed waste volumes, methods for removal and packaging of waste materials, and disposal options for radioactive and mixed waste generated during decommissioning. The data will also be incorporated into the decision-making process for the development of the FSS data quality objectives described in NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM), Revision 1 (ML003761445).

Overall, the ARRR Site Characterization Report provides a detailed status of the radiological conditions at the facility. Characterization efforts were guided by a thorough historical site assessment (HSA) and characterization plan. Characterization activities included fixed-point surveys, scanning surveys, removable contamination measurements, and gamma radiation surveys. The onsite surveys conducted at the ARRR facility included measurements of removable contamination levels, total (fixed plus removable) surface activity levels, radiation exposure rates, and sampling of various media for analysis at an offsite laboratory. The offsite analyses determined the specific radionuclides present, and in some cases, the volumetric concentration of radionuclides. In addition, biased measurements were performed and biased samples were obtained at locations that were the most likely to exhibit elevated contamination or radiation levels, based on site operations. The information obtained from the site characterization effort provides sufficient data to demonstrate that it is unlikely that significant quantities of residual radioactivity have gone undetected in the ARRR. Table 3-2, Characterization Survey Summary, of the ARRR DP summarizes the results of the characterization survey and identifies areas containing residual radioactivity.

Section 4.2.2.2, Radionuclides, of the ARRR DP discusses expected radionuclides present at ARRR. The list assumes that reactor operation resulted in neutron activation of reactor core components and other integral hardware, or structural members situated adjacent, or in close proximity, to the reactor core. Table 4-1, List of Expected Radionuclides, of the ARRR DP contains a list of radionuclides possibly present at detectable levels within the ARRR. The licensee stated that the determination of residual activity levels in reactor components and structures surrounding the reactor is based upon theoretical neutron activation calculations;

however, during active decommissioning, remediation and other actions will be determined based on direct measurements and sampling.

3.3.3 Radiological Release Criteria

The licensees proposed decommissioning plan, a period of safe storage followed by entering active decommissioning upon removal of fuel from the site, does not necessitate the major dismantlement of ARRR buildings. The licensee stated that the results of the site and facility radiological characterization to date have indicated that the building structures are directly releasable without extensive need for decontamination.

In order to determine whether the residual radioactivity remaining at the ARRR site meets the radiological criteria for unrestricted release, ARRR states that the FSS will use Derived Concentration Guideline Levels (DCGLs) developed from the characterization survey data. The licensee expects that the remaining soil and building surfaces will satisfy the requirements of 10 CFR 20.1402, and that the residual radioactivity that is distinguishable from background radiation will not result in a Total Effective Dose Equivalent (TEDE) to an average member of the critical group that exceeds 25 millirem per year (mrem/yr), and that the residual radioactivity will have been reduced to levels that are as low as reasonably achievable (ALARA).

Section 4.7, Facility Release Criteria, of the ARRR DP also states that the release criteria will be determined to have been met by demonstrating that the surface or volumetric activities meet their respective NRC screening values, as found in Appendix B, Screening Values, of NUREG-1757, Consolidated Decommissioning Guidance, Volume 1, Decommissioning Process for Materials Licensees, Revision 2 (ML063000243). These screening values (meeting the 10 CFR 20.1402 criteria) are provided for several common radionuclides for building surface and surface soil contamination, and are duplicated in Table 4-6, License Termination Screening Values for Building Surface Contamination, and Table 4-7, License Termination Screening Values for Surface Soil, of the ARRR DP.

The licensee also noted that the site and facility radiological characterization information to date does not indicate that there is any surface soil contamination present at the ARRR. Therefore, the unrestricted release criteria for surface soil will be based upon the relative concentrations of isotopes measured in the material during the active decommissioning phase, and their respective release criteria, if more than one category of radionuclide for beta-gamma emitters applies from Table 4-7 of the ARRR DP. If additional screening values are required for radionuclides not included in Table 4-6 or Table 4-7 of the ARRR DP, they will be calculated using the NRC's D & D Code with default values. Finally, Section 4.3.1.1.2, General Cleanup of ARRR, of the ARRR DP states that equipment, materials, instrumentation, and tools that are used or encountered during active decommissioning will be surveyed and released as clean waste only if the residual radioactivity is less than the current site release limits of 200 disintegrations per minute (dpm) per 100 square centimeters (cm2) measurable beta contamination above background radiation and 30 dpm/100 cm2 measurable alpha contamination above background radiation.

The licensee noted that an ALARA analysis is not needed when using the license termination screening values to meet the NRCs radiological criteria for unrestricted release. As stated in NUREG-1757, Volume 2: In light of the conservatism in the building surface and surface soil generic screening levels developed by the NRC staff, the staff presumes, absent information to the contrary, that licensees or responsible parties that remediate building surfaces or soil to the generic screening levels do not need to provide analyses to demonstrate that these levels are

ALARA. In addition, if residual radioactivity cannot be detected, it may be assumed that it has been reduced to levels that are ALARA. Therefore, the licensee may not need to conduct an explicit analysis to meet the ALARA requirement. Accordingly, the NRC staff agrees that an ALARA analysis would not required for the ARRR if the future FSS results confirm that the remaining radioactivity at the site meets the NRC screening values for unrestricted release.

3.3.4 Conclusion

The NRC staff reviewed the ARRR site and facility radiological characterization information provided by the licensee to date. The NRC staff finds this version of the ARRR DP is acceptable when reviewed as a less detailed decommissioning plan pursuant to 10 CFR 50.82(b)(2) because the fuel remaining in the pool is physically preventing the full site characterization necessary for the licensee to develop a DP that meets the regulatory requirements of 10 CFR 50.82(b)(4)(ii). However, a more complete characterization of the radiological conditions at the facility will be needed in the updated DP to determine if the controls and limits on procedures and equipment, to protect the occupational and public health and safety during the active dismantlement of the site, are adequate.

Specifically, a more complete characterization of the radiological conditions and residual activity levels in reactor components and structures surrounding the reactor will be needed, including characterization of the inside surfaces of the reactor pool, after the pool water is removed, to address potential contamination from leaking fuel elements. In addition, the NRC staff notes that the ARRR DP makes no mention of surface water or groundwater considerations for the ARRR site. This information will be necessary to allow the NRC staff to make the health and safety conclusions required pursuant to 10 CFR 50.82(b)(4)(ii), and as described by NUREG-1537, Part 2, Appendix 17.1, Section 2.2.2, Current Radiological Status of the Facility. Since the licensee is required to provide a more detailed version of the ARRR DP before active decommissioning begins, that updated DP will be reviewed by the NRC as part of the overall decommissioning approval process to ensure that it appropriately addresses the radiological conditions as they relate to occupational and public health and safety.

The NRC staff also reviewed the release criteria proposed by the licensee and concludes that because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2),

which allows for less detailed decommissioning planning while the facility is in storage and surveillance, this version of the ARRR DP is acceptable. However, since the licensee commits to two different methods of establishing unrestricted release criteria in the DP, using both site-specific DCGLs, which have not yet been developed, and the generic screening levels found in NUREG-1757, Volume 1, the NRC staff is unable to determine whether there is sufficient information in the current ARRR DP to demonstrate compliance with the radiological release criteria of 10 CFR 20.1402.

The NRC staff also notes that Section 4.3.1, Activities and Tasks, of the ARRR DP contains a discussion of potentially elevated activity related to Carbon-14 (C-14), Calcium-41 (Ca-41),

Calcium-45 (Ca-45), Manganese-54 (Mn-54), Iron-55 (Fe-55), and Cobalt-60 (Co-60) being present in the soils associated with the reactor and pool, as well as the reactor building walls, which will have to evaluated and dispositioned before the NRC can conclude that the release criteria have been met. Because the licensee is required to provide a more detailed version of the ARRR DP before active decommissioning begins, which will be reviewed by the NRC as part of the overall approval process for the updated DP to ensure that it appropriately addresses the radiological release criteria, the NRC staff finds this less detailed version of the ARRR DP acceptable, consistent with 10 CFR 50.82(b)(2).

3.4 Decommissioning Tasks

3.4.1 Scope of the Decommissioning Project

Section 4.3, Decommissioning Tasks, of the ARRR DP discusses the remaining decontamination and dismantlement activities at the facility to complete decommissioning and prepare the site for unrestricted release, as well as providing a description of each area and component at the ARRR that will be subject to active decommissioning activities in the future.

This section states that the ARRR DP pertains to the dismantling of the reactor and associated systems in a safe manner, in accordance with the ALARA principles, and leading to the decontamination and FSS of the entire ARRR facility and site. This section of the ARRR DP also states that in preparation for future active decommissioning activities, non-reactor-related equipment and materials situated throughout the facility complex will be collected, surveyed, packaged, and appropriately dispositioned in accordance with established Aerotest procedures.

A high-level overview of the planned decommissioning activities for the ARRR, and their approximate order of completion, can be found in Section 4.3.1.2, Dismantling Sequence, and Figure 4-2, ARRR Decommissioning Schedule, of the ARRR DP. Items to be removed during active decommissioning will be placed into four groups as follows:

Group 1 Equipment that does not have induced radioactivity, but which may have surface contamination (see Table 4-2, Components with Potential Surface Contamination -Group 1, of the ARRR DP).

Group 2 Core components and other components that have induced radioactivity, including pool concrete that has been activated (see Table 4-3, Components with Induced Radioactivity - Group 2, of the ARRR DP).

Group 3 Reactor support systems (see Table 4-4, Reactor Support System - Group 3, of the ARRR DP).

Group 4 Equipment, tools and systems that become contaminated during decommissioning operations (see Table 4-5, Equipment Used in Decommissioning Operations - Group 4, of the ARRR DP).

In general, the dismantling of the ARRR will occur sequentially as follows:

1) remove shielding around reactor area,

2) remove reactor and neutron radiography components,

3) empty reactor pool and process water,

4) decontaminate reactor pool tank,

5) remove auxiliary systems,

6) decontaminate facility surfaces,

7) remove the reactor pool tank and backfill the excavation,

8) perform FSS activities for the remaining licensed facility and site.

3.4.2 Schedule

According to the ARRR DP, Aerotest estimates that a formal request for termination of NRC Facility License No. R-98 will be submitted approximately eighteen months after removal of fuel

from the site. The preliminary portion of the ARRR decommissioning activities (prior to fuel removal) is projected to run for six months. The NRC staff notes that Aerotest has already begun non-major decommissioning activities such as collection of non-reactor-related equipment and materials. The licensee stated that changes to the ARRR decommissioning schedule may occur as a result of changes to fuel disposition plans, resource allocation, availability of a radioactive waste disposal site, ALARA considerations, and the results of additional radiological characterization measurements.

3.4.3 Conclusion

The NRC staff reviewed the ARRR facility decommissioning tasks and the manner in which the licensee proposes to complete each of the decommissioning tasks. Because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance, the NRC staff finds this version of the ARRR DP acceptable. The list of activities outlining decommissioning tasks and plans for removing components is consistent with the guidance provided in NUREG-1537, Part 1, Appendix 17.1, Section 2.3, Decommissioning Tasks. However, more information regarding methods to complete these tasks, or the criteria against which successful completion of these tasks will be gauged, will be needed in the updated DP for the NRC staff to review these methods for acceptability pursuant to the 10 CFR 50.82(b) requirement that updated detailed plans must be submitted and approved prior to the start of these activities.

The proposed overall schedule for accomplishing the remaining ARRR decommissioning tasks is compatible with the quantity of radioactivity to be removed and meets the requirements of 10 CFR 50.82(b)(4)(i), which state that decommissioning must be completed without significant delay, unless a delay is necessary to protect public health and safety. The guidance in NUREG-1700, Standard Review Plan for Evaluating Nuclear Power Reactor License Termination Plans, Revision 2 (ML18116A124), lists scenarios relevant to this regulation, including unavailability of radioactive waste disposal facilities, which is applicable to ARRR.

The NRC staff notes that more detailed schedule information is expected to be provided as part of the revision to the ARRR DP that will be submitted before active decommissioning begins, consistent with the guidance provided in NUREG-1537, Part 1, and in accordance with 10 CFR 50.82(b). However, because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance, the NRC staff finds the information in this version of the ARRR DP acceptable.

3.5 Decommissioning Organization and Responsibilities

According to Section 4.4, Decommissioning Organization and Responsibilities, of the ARRR DP, Aerotest is committed to, and retains ultimate responsibility for, full compliance with the existing NRC reactor license and all applicable regulatory requirements during decommissioning. The ARRR DP states that the Aerotest President, with support from the Reactor Safeguards Committee (RSC), will monitor decommissioning operations to ensure they are being performed safely and in accordance with the applicable federal (NRC, U.S. Environmental Protection Agency (EPA), and U.S. Department of Transportation (DOT)),

state, and local regulatory requirements, and will approve decommissioning procedures for use during active dismantlement and decontamination as described in the ARRR DP.

In addition, consistent with Aerotest policy, the ARRR RSC has certain responsibilities to review and approve policies, procedures, programs, and facilities pursuant to the safe use of radiological materials and radiation producing equipment. The RSC's jurisdiction will extend to all decommissioning activities dealing with radioactive material and radiological controls.

According to the ARRR TS, and as further discussed in the Aerotest letter dated July 21, 2022, the RSC will be responsible for, but not limited to the following:

• Reviewing and approving nuclear safety standards associated with the use of the facility.

• Reviewing the ARRR facility's procedures and modifications.

• Determining whether proposed changes to the facility or procedures are allowed without prior authorization by the NRC, in accordance with 10 CFR 50.59, Changes, tests, and experiments.

• Conducting periodic audits of procedures, maintenance activities, equipment performance, and record retention requirements.

• Reviewing all reported violations of the TS, evaluating the causes of such events and the corrective actions taken, and recommending measures to prevent reoccurrence.

• Reporting findings and recommendations concerning the above to the Aerotest President.

The proposed Aerotest organization for the ARRR decommissioning activities is shown in Figure 4-3, ARRR Decommissioning Organization, of the ARRR DP.

3.5.1 Contractor Assistance

The licensee stated that Aerotest management will maintain responsible staff to perform the ARRR decommissioning project. The team will consist of Aerotest personnel, selected advisors, and contract support, as needed, who will be selected through established corporate procurement procedures and standards requiring a rigorous source evaluation and review process. The review and evaluation will include defined criteria such as qualifications, experience, and reputation. Personnel, consultants, and subcontractors performing work under the ARRR DP will be required to comply with applicable Aerotest policies and procedures.

Aerotest will maintain overall project management and provide for oversight of contractors.

The NRC staff notes that if Aerotest plans to employ a decommissioning contractor to decontaminate and dismantle the ARRR, the qualifications and experience of the contractor should be discussed in the updated DP submitted in support of active decommissioning in the future. Such a contractor could manage the physical aspects of the ARRR decommissioning work, including work planning, QA, health physics, training, safety, waste processing, and waste packaging and shipping, as well as preparation of the FSS report.

3.5.2 Functions of Specific Licensee Staff

Key licensee positions are described in Section 4.4.2, Aerotest President, Section 4.4.3, Reactor Administrator, and Section 4.4.4, Radiation Safety Officer, of the ARRR DP.

According to the ARRR DP, the functions of the Aerotest President include:

• Controlling and maintaining safety during decommissioning activities and protection of the environment.

• Reporting of performance.

• Approving minor changes to the DP and procedures (which do not change the original intent and do not involve an unreviewed safety question).

• Oversight and coordination of Aerotest functional groups and decommissioning contractors.

• Ensuring that the conduct of decommissioning activities complies with applicable regulations and is in accordance with the ARRR facility license.

According to the ARRR DP, the functions of the ARRR Reactor Administrator will include:

• Responsibility for ensuring security and safety of the ARRR facility.

• Maintaining the new, unirradiated, and used, irradiated, TRIGA fuel in a safe and proper condition during the evolution of the ARRR decommissioning project activities, in accordance with the requirements set forth in the ARRR facility license.

• Review of decommissioning activity plans and procedures.

• Providing engineering support for the decommissioning activities.

• Enforcing, reviewing, and amending procedures associated with security and safety programs.

• The reactor administrator is responsible to the Aerotest President.

According to the ARRR DP, the ARRR Radiation Safety Officer (RSO) will be responsible for providing radiological protection and support during the active decommissioning of the ARRR.

The RSO and the associated radiation safety organization will also have the independent authority to stop work at the site during active decommissioning, as discussed in the Aerotest letter dated July 21, 2022.

According to the ARRR DP, the ARRR RSO is responsible for ensuring or providing:

• Radiological controls are in place prior to and during any work involving radiation.

• Applicable license conditions are satisfied.

• Applicable state and federal regulations are met.

• Review and approval of all procedures involving radiological safety.

• Enforcement of rules, regulations, and procedures relating to radiological safety.

• The conduct of routine radiation surveys.

• The RSO is responsible to the Aerotest President.

3.5.3 Conclusion

The NRC staff reviewed the ARRR DP with respect to the proposed decommissioning organization and responsibilities. The NRC staff concludes that this information satisfies the requirements of 10 CFR 50.82(b)(4)(v) regarding QA provisions, when reviewed as a less detailed plan consistent with 10 CFR 50.82(b)(2), because the licensee has provided reasonable assurance that the organizational structures needed to safely decommission ARRR are, or will be, in place. As noted above, if Aerotest plans to employ a decommissioning contractor to decontaminate and dismantle the ARRR, the qualifications and experience of the contractor should be discussed in the updated DP submitted in support of active decommissioning in the future. In addition, the licensee has committed to ensuring that the ARRR RSC will properly oversee all decommissioning activities, including the review and approval of changes to the facility and of decommissioning related plans and procedures. The NRC staff finds that the project management structure for the decommissioning of the ARRR is consistent with the guidance on the role and composition of the facility safety committee provided in Section 2.4, Decommissioning Organization and Responsibilities, of Appendix 17.1 to NUREG-1537, Part 1, and is therefore acceptable.

3.6 Training Program

According to Section 4.5, Training Program, of the ARRR DP, individuals (personnel, consultants, contractors, and visitors) who require access to the work areas or a radiologically restricted area at the facility will receive training commensurate with the potential hazards to which they may be exposed. Radiation protection training will be provided to personnel who will be performing remediation work in radiological areas or handling radioactive materials. The training will ensure that decommissioning project personnel have sufficient knowledge to perform work activities in accordance with the requirements of the radiation protection program and accomplish ALARA goals and objectives. The principal objective of the ARRR training program is to ensure personnel understand the responsibilities and the required techniques for safe handling of radioactive materials and for minimizing exposure to radiation.

Records of training will be maintained, which will include the trainees names, dates of training, type of training, test results, authorization for protective equipment use, and instructor's name.

3.6.1 General Site Training

According to Section 4.5.1, General Site Training, of the ARRR DP, a general training program designed to provide orientation to project personnel and meet the requirements of 10 CFR Part 19, Notices, Instructions, and Reports to Workers: Inspection and Investigations, will be implemented. General Site Training will be required for all personnel assigned on a regular basis to the ARRR remediation project.

The training will include, but is not limited to:

• Project orientation, security, and access control.

• Introduction to radiation protection.

• Quality assurance.

• Industrial safety.

• Emergency procedures.

3.6.2 Radiation Personnel Training

According to Section 4.5.2, Radiation Personnel Training, of the ARRR DP, Radiation Personnel Training (RWT) will be required for all individuals directly associated with the ARRR decommissioning project, and the training will include the following topics:

• Fundamentals of radiation.

• Biological effects of radiation.

• External radiation exposure limits and controls.

• Internal radiation limits and controls.

• The ALARA program (objectives, investigational limits, keeping doses ALARA).

• Contamination limits and controls.

• Management and control of radioactive waste.

Section 4.5.2 of the ARRR DP states that personnel who have documented equivalent RWT from another site may be waived from taking most of the site-specific training listed above, except for training on Aerotest administrative limits and emergency response, and will be required to pass the written examination and demonstration exercises.

3.6.3 Respiratory Protection Training

According to Section 4.5.3, Respiratory Protection Training, of the ARRR DP, personnel whose work assignments require the use of respiratory protection devices will receive respiratory protection training on the devices and techniques that they will be required to use.

The ARRR DP states that the training program will follow the requirements of Subpart H, Respiratory Protection and Controls to Restrict Internal Exposure in Restricted Areas, of 10 CFR Part 20 and 29 CFR 1910.134, Respiratory protection. In addition, the ARRR DP states that the training program will be implemented using the guidance provided in NRC Regulatory Guide 8.15, Acceptable Programs for Respiratory Protection, Revision 1 (ML003739512), and NUREG/CR-0041, Manual of Respiratory Protection Against Airborne Radioactive Material, Revision 1 (ML010310331). The ARRR DP also states that training will consist of a lecture session and a simulated work session. Personnel who have documented equivalent respiratory protection training may be waived from this training.

3.6.4 Industrial Safety Program

Section 5.3, General Industrial Safety Program, of the ARRR DP discusses the general industrial safety program for the site, which includes a discussion of non-radiological accident prevention and mitigation. This section of the ARRR DP states that the Aerotest President will be responsible for ensuring that the ARRR decommissioning project meets all occupational health and safety requirements. The primary functional responsibility is to ensure compliance with the requirements established by the Occupational Safety and Health Administration (OSHA). Specific responsibilities include conducting an industrial training program to instruct personnel in general safe work practices; reviewing ARRR decommissioning project procedures to verify adequate coverage of industrial safety and industrial hygiene concerns and requirements; and performing periodic inspections of work areas and activities to identify and correct any unsafe conditions and work practices.

Section 5.3 of the ARRR DP also states that all personnel working on the decommissioning project will receive health and safety training in order to recognize and understand the potential

risks involving personnel health and safety associated with work at the ARRR. The implementation of this health and safety training will ensure compliance with the requirements of the NRC contained in 10 CFR, the requirements of the EPA found in Title 40, Protection of the Environment, of the CFR, and the OSHA requirements in Title 29, Labor, of the CFR.

3.6.5 Conclusion

The NRC staff reviewed the licensees training program as described in the ARRR DP. Because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance, the NRC staff finds the current training program described in the ARRR DP acceptable. However, also in accordance with 10 CFR 50.82(b)(2), the licensee is required to provide a more detailed version of the ARRR DP before active decommissioning begins, which will be reviewed by the NRC as part of the overall approval process for the updated DP to ensure that it appropriately addresses the training program requirements for active decommissioning. Specifically, the licensee does not include information in the ARRR DP related to designated training personnel, training personnel qualifications, time allotted to training, or clear methods for evaluating the effectiveness of training, as outlined by NUREG-1537, Part 2, Appendix 17.1, Section 2.5, Training Program, and pursuant to 10 CFR 50.82(b)(4)(v) regarding QA provisions.

The licensee also recognized that specific training would be required to reflect the unique hazards associated with decommissioning operations. While the NRC does not regulate non-radiological hazards as specified by the Atomic Energy Act, as amended, the licensee is aware that personnel involved with decommissioning project activities are subject to training requirements administered by other Federal, state, and local government agencies and has committed to provide training commensurate with the potential hazards to which individuals may be exposed during the ARRR decommissioning project.

3.7 Radiation Protection

3.7.1 ALARA Program

Section 5.1.1, Ensuring As Low As Reasonably Achievable (ALARA) Radiation Exposures, of the ARRR DP describes the ALARA program for the ARRR decommissioning project, and states that the licensee will conduct the ARRR decontamination and dismantlement activities in such a way to minimize exposures to workers and the public ALARA. The ARRR DP provides the expectation that all decommissioning personnel be knowledgeable of decontamination and dismantlement activities and follow all ALARA requirements documented in policies and procedures, as well as be responsible for minimizing dose to themselves and others.

Section 5.1.1 of the ARRR DP also discusses the specific Aerotest practices during the ARRR decommissioning project that will be utilized to maintain doses ALARA. Namely, a documented ALARA evaluation will be required for specific tasks if the RSO determines that 50 percent (%)

of the applicable dose limits (collective dose) for any of the following may be exceeded:

• TEDE (5 rem).

• The sum of the Deep-Dose Equivalent and the Committed Dose Equivalent to any individual organ or tissue other than the lens of the eye (50 rem).

• Eye Dose Equivalent (15 rem).

• Shallow-Dose Equivalent to the skin or any extremity (50 rem).

In addition, various methods will be utilized during decommissioning work to ensure that occupational exposure to radioactive material is kept ALARA, including the use of Radiological Work Permits (RWPs), special equipment including the establishment of a respiratory protection program, and ALARA techniques and practices. The specifics of these practices include establishing work techniques in such a manner that the exposure for all personnel, individually and collectively, are maintained ALARA; explaining in the RWP any special instructions or precautions pertinent to radiation hazards in the area, including listing the radiological hazards present, area dose rates and the presence and intensity of hotspots, loose surface radioactivity, and other hazards as appropriate; and maintaining appropriate controls for the storage of radioactive material, including minimization of the volume of radioactive wastes generated during decommissioning of the ARRR facility.

3.7.2 Health Physics Program

Section 5.1.2, Health Physics Program, of the ARRR DP describes the health physics (HP) program for the ARRR decommissioning project, and states that (1) the RSO, while organizationally independent of the decommissioning project staff, has direct access to the Aerotest President and will have full authority to act in all aspects of protection of personnel and the public from the effects of radiation; (2) during the ARRR decommissioning project, aspects of the HP program may be assessed through audits, assessments, and inspections of various aspects of decommissioning performance in accordance with 10 CFR Part 20; and (3) HP equipment and instrumentation suitable to permit ready detection and quantification of radiological hazards to personnel and the public will be available to ensure the validity of measurements taken during remediation and final release surveys.

In addition, the ARRR HP program will satisfy individual commitments in the following areas:

• Storage, calibration, testing, and maintenance of HP equipment and instrumentation.

• Airborne effluent monitoring.

• The conduct of radiation surveys.

• Internal and external personnel monitoring.

• Respiratory protection equipment maintenance and storage.

• Contamination control, access control, and engineered controls.

• Airborne radioactivity monitoring, as required by 10 CFR 20.1502(b).

• Potential sources of radiation or contamination exposure to personnel and the public as a result of decommissioning activities at the ARRR.

Aerotest has HP procedures in place that will be implemented during the ARRR decommissioning project. Additional HP procedures may be required and will be developed and approved in accordance with Aerotest policy and procedure. The NRC staff notes that any future changes or additions to the licensees HP procedures would be subject to the

requirements in 10 CFR 50.59 as applicable. Section 5.1.2 of the ARRR DP also states that the licensee will control the potential sources of radiation exposure to personnel and the public as a result of decommissioning activities through the use of administrative, engineering, and physical controls, among other considerations.

According to the ARRR DP, administrative controls consist of, but are not limited to:

• Administrative dose limits that are lower than regulatory limits.

• Training.

• Radiological surveys.

The licensee may also employ physical barriers, such as radiological warning rope/ribbon, in combination with radiological warning tape, lockable doors and gates, as well as information signs and flashing lights or other applicable barriers.

According to the ARRR DP, engineering controls may consist of, but are not limited to:

• HEPA ventilation/enclosures.

• Protective clothing/equipment.

• Access restrictions/barriers.

• Confinement.

3.7.3 Radioactive Materials Controls

Section 5.1.3, Radioactive Materials Controls, of the ARRR DP describes the aspects of the Aerotest radiation protection program that establish radioactive material controls to ensure:

• Prevention of inadvertent release of decommissioning radioactive waste material to uncontrolled areas at the site.

• Assurance that personnel are not inadvertently exposed to radiation from licensed radioactive decommissioning waste materials.

• Minimization of the amount of radioactive waste material generated during decommissioning.

According to the ARRR DP, decommissioning waste materials that can be released will be surveyed and removed for general disposal, while contaminated materials will be shipped to an offsite licensed radioactive waste processing facility for survey, processing, and disposal. In addition, the release of any reactor pool water will be analyzed and filtered to ensure that discharges to sanitary sewerage will meet the requirements of 10 CFR 20.2003, Disposal by release into sanitary sewerage, and the Aerotest liquid discharge procedures.

Based on the above discussion, the NRC staff notes that, collectively, the ARRR HP program will (1) implement the procedures defined in the radiation protection program; (2) ensure radiological safety of the public, occupationally exposed personnel, and the environment; (3) monitor radiation levels and radioactive materials; (4) control the distribution and release of radioactive materials; (5) maintain potential exposures to the public and occupational radiation exposure to individuals within administrative limits and the regulatory limits of 10 CFR Part 20 and ALARA; and (6) monitor personnel internal and external exposure in accordance with the

10 CFR Part 20 requirements. Although additional details may be needed in some of these areas before approval of an updated DP and start of active decommissioning at the site, as discussed in Section 3.7.5 below, the general structure of the ARRR radiation protection program appears adequate to protect public health and safety when reviewed under the less detailed standard of 10 CFR 50.82(b)(2).

3.7.4 Dose Estimates

Section 5.1.4, Dose Estimates, of the ARRR DP states that the total projected occupational exposure to complete the decommissioning of the ARRR is estimated to be 18.34 person-rem.

This dose estimate for decommissioning the ARRR reactor was taken from NUREG/CR-1756, Technology, Safety and Costs of Decommissioning Reference Nuclear Research and Test Reactors (ML080500542). The dose estimate in this document was developed for a reference nuclear research reactor, which was a 1,000-kilowatt TRIGA reactor. The ARRR DP states that the dose estimate is provided for planning purposes only and uses area dose rates based on process knowledge and current survey maps (where available). Detailed dose estimates and exposure controls will be developed in accordance with the requirements of the ALARA program during detailed planning for the active phase of the ARRR decommissioning activities.

According to the ARRR DP, the dose estimate to members of the public as a result of decommissioning activities is estimated to be negligible (less than 0.1 person-rem) because site perimeter controls will restrict members of the public from the area where decommissioning activities are taking place. This approach is consistent with the dose estimate given for a reference research reactor in NUREG-0586, Final Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities (ML18057B048). NUREG-0586 states that the dose to the public during active decommissioning and truck transportation of radioactive waste from a reference research reactor is estimated to be negligible (less than 0.1 person-rem).

3.7.5 Conclusion

The NRC staff reviewed the licensees commitments to decommissioning ALARA and HP programs and the estimate of the potential dose from the ARRR decommissioning activities provided by the licensee to date. Because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance, the NRC staff finds this version of the ARRR DP acceptable. However, as also required by 10 CFR 50.82(b)(2), the licensee must provide a more detailed version of the ARRR DP before active decommissioning begins, which will be reviewed by the NRC as part of the overall approval process for the updated DP, to ensure that it appropriately addresses the ALARA requirements for active decommissioning. Specifically, the section in the ARRR DP regarding an ALARA program does not include information on methods for maintaining exposure to the public ALARA, personnel training, procedural reviews, or walkthroughs to ensure work activities are consistent with the ALARA goals pursuant to 10 CFR 50.82(b)(4)(ii), and as described by NUREG-1537, Part 2, Appendix 17.1, Section 3.1.1, Ensuring ALARA Radiation Exposures.

The NRC staff finds that the radiation protection controls described by the licensee as part of the ARRR HP program will maintain doses within the 10 CFR Part 20 limits, specifically those found in 10 CFR 20.1201, Occupational dose limits for adults, and be in accordance with ALARA principles. These controls are adequate to protect occupational health and safety and therefore satisfy the occupational component of the requirements found in

10 CFR 50.82(b)(4)(ii), which states that the DP must include a description of the controls and limits on procedures and equipment to protect occupational and public health and safety.

The NRC staff notes that the ARRR DP does not include specific dose estimates for major decommissioning tasks, but states that they will be developed during detailed planning for active decommissioning activities. Specific dose estimates should be provided for each task identified in Section 4.3 of the ARRR DP in the updated detailed DP, pursuant to 10 CFR 50.82(b)(2). In addition, the NRC staff notes that Section 5.1.1 of the ARRR DP discusses ALARA evaluations for specific decommissioning tasks but does not describe the proposed procedures for disposition of small areas of elevated radioactivity, or hotspots. Accordingly, the updated detailed DP should include further discussion of the ALARA considerations and practices for removing small areas of elevated radioactivity.

3.8 Radioactive Waste Management

Section 5.2.1, Radioactive Waste Processing, of the ARRR DP describes the licensees proposed program to manage and control the solid and liquid radioactive waste for the ARRR decommissioning project. The licensee stated that processes for decontamination, remediation, and dismantlement of the ARRR will result in the generation of solid and liquid low-level radioactive waste, mixed waste, and hazardous waste. Limited soil remediation is anticipated that would result in solid radioactive waste. According to the ARRR DP, this waste will be handled (processed and packaged), stored and disposed of in accordance with the applicable NRC regulations, disposal site Waste Acceptance Criteria, California Department of Public Health requirements, the commitments in the ARRR facility licenses and permits, and the applicable implementing plans and procedures. Radioactive waste processing includes waste minimization or volume reduction, radioactive and hazardous waste segregation, waste characterization, stabilization, solidification, and packaging.

3.8.1 Radioactive Waste Disposal

Section 5.2.2, Radioactive Waste Disposal, of the ARRR DP states that low-level radioactive waste will be processed and packaged for disposal at a licensed low-level waste site. Mixed low-level waste will be prepared for shipment to offsite commercial processing and disposal facilities. These disposal shipments will be conducted in accordance with the requirements of Subpart D, Technical Requirements for Land Disposal Facilities, of 10 CFR Part 61, Licensing Requirements for Land Disposal of Radioactive Waste, to ensure appropriate waste classification, as well as the appropriate characterization and labeling requirements for the radionuclide content of a specific shipment.

This section of the ARRR DP also discusses the various requirements that the licensee will adhere to in order to ensure that Aerotest will process all radioactive waste in controlled areas to minimize radiation exposure to personnel and the spread of contamination. The licensee will package waste to meet the applicable DOT requirements in 49 CFR Part 173, Shippers -

General Requirements for Shipments and Packagings, 10 CFR Part 20, and 10 CFR Part 71, Packaging and Transportation of Radioactive Material, as well as the disposal facility's criteria for transportation and disposal for each decommissioning waste stream. The licensee also states that Aerotest will meet the requirements of 10 CFR 20.2006, Transfer for disposal and manifests, which establishes requirements for controlling transfers of low-level radioactive waste intended for disposal at a land disposal facility; establishes a manifest tracking system; supplements requirements concerning transfers and record keeping; and requires generator

certification that transported materials are properly classified, described, packaged, marked and labeled, and are in proper condition for transport.

According to the ARRR DP, the majority of these requirements will be met through the implementation of Aerotest packaging and shipping procedures for the ARRR decommissioning project under the oversight of the Aerotest President and ARRR RSC. In addition, Aerotest will ensure that generator State (California) and treatment/storage/disposal facility states (Utah, etc.) requirements for radioactive and mixed waste management will be incorporated into the ARRR plans and procedures to assure conformance with the applicable state regulations, ARRR licenses, and permits. Specifically, radioactive waste will be staged in designated controlled areas in accordance with the 10 CFR Part 19 and 10 CFR Part 20 requirements; mixed wastes will be staged in designated controlled areas per the applicable EPA requirements, the NRC requirements, and in accordance with local and state permits. The licensee also states that measures will be implemented through plans and procedures to control the spread of contamination, limit radiation levels, and prevent unauthorized access, unauthorized material removal, tampering, and weather damage.

According to the ARRR DP, radioactive and mixed waste material will be packaged for shipment and placed in permitted interim storage (staged) until shipped. The quantity of waste packages staged for shipment will be a function of waste generation and packaging rate, shipment preparation rate, shipment rate, and disposal site acceptance rate. To meet this objective, shipments from ARRR will be scheduled throughout the life of the decommissioning project to designated treatment, storage, and disposal facilities. Finally, radioactive material storage areas will be contained inside posted restricted areas according to existing Aerotest procedures, and consistent with the applicable requirements in 10 CFR Part 20.

3.8.2 Conclusion

The NRC staff reviewed the licensees proposed decommissioning waste management program and concludes that because this version of the DP was evaluated against the requirement in 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance, this version of the ARRR DP is acceptable. Until such time as the fuel is moved out of the pool, the characterization, remediation, and dismantlement of the remainder of the ARRR site is infeasible and prevents the licensee from developing a detailed DP that fully analyzes the radioactive waste management requirements of the site. Once major decommissioning activities can commence after the fuel is removed from the pool, this information can be supplemented and reviewed by the NRC staff.

In addition, as required by 10 CFR 50.82(b)(2), a more detailed DP must be submitted and approved prior to the start of decommissioning activities. A more detailed DP which meets all of the applicable requirements of 10 CFR Parts 20, 50, and 71, as well as 10 CFR Part 73, Physical Protection of Plants and Materials, should include a complete description of the radioactive waste management plans to determine if the radioactive waste management program for active decommissioning is sufficient to control, process, package, and transport radiological waste, as described by NUREG 1537, Part 2, Appendix 17.1, Section 3.2, Radioactive Waste Management.

The NRC staff notes that the ARRR DP does not specify designated disposal sites, methods of transportation, waste characterization, waste volume, or certification plans. In addition, future updates to the ARRR radioactive waste management plans should include (1) a discussion of the disposition of all fuel; (2) a description of waste management systems and procedures; and

(3) a description of planned radioactive waste disposal, including estimates of type and quantify of waste, transportation modes, and disposal locations. The plan should also provide detailed guidance for the characterization, sampling, classification, segregation, handling, packaging, manifesting, transporting, and disposal of waste generated by the ARRR decommissioning activities. In addition, these plans should define the radioactive waste management and pollution prevention programs prior to beginning active decommissioning operations. Finally, the radioactive waste management plan should describe how the licensee will perform appropriate processing, packaging, and monitoring of solid and liquid wastes generated during the process in accordance with formally approved administrative and technical procedures.

3.9 Radiological Accident Analysis

Section 5.4, Radiological Accident Analysis, of the ARRR DP states that potential radiological accidents that could occur during the decommissioning of the ARRR were evaluated by determining which ARRR components and areas contain the highest radioactive material inventory and using those parameters in conducting the associated analyses. The proposed decommissioning activities and methods by which radioactive material could be released to the work area or environment were considered. Since, based on information in the DP, all special nuclear material will have been removed from the site prior to active decommissioning, the majority of the accidents discussed in the current ARRR license are not applicable. Further, the ARRR accident identification process was supplemented by reviewing experiences at other non-power reactor decommissioning projects. The following radiological accidents at ARRR were considered to present the highest potential consequences during active decommissioning: (1) a fire in the waste storage area; (2) a fire in activated graphite; (3) a dropped and damaged ion exchange column; (4) a dropped irradiated hardware liner; and (5) a transportation accident.

3.9.1 Fires

Section 5.4.1, Fire in Waste Storage Area, of the ARRR DP states that the consequences of a fire during decommissioning of the ARRR were considered by the licensee and determined to not be significantly different than the consequences of a fire during reactor operations. Similar to when the ARRR was operational, most materials present during decommissioning will be metals, concrete, or similar non-combustible materials. Although the licensee stated that some torch cutting operations may be performed during decommissioning, the likelihood is low that a fire would start or that a fire could become intense enough to release radioactive material.

3.9.1.1Fire in a Waste Storage Area

Section 5.4.1 of the ARRR DP goes on to state that the waste storage area fire scenario is for a fire to occur in the dry solid waste. The licensee discusses that dry radioactive waste is normally collected and packaged in metal containers to limit the volume of dry radioactive waste available for consumption by fire. For this scenario, it was assumed that the activity concentration in the dry solid waste material will be 10% of the concentration present in the reactor pool cleanup resin. The licensee considers this a conservative assumption as the reactor pool cleanup resin column concentrates radioactivity, and most of the dry solid waste material at ARRR will have minimal contamination. Accordingly, a waste inventory of 360 cubic feet of dry solid waste was estimated to contain 0.11 millicuries of contamination assuming it would have the same activity distribution as the reactor pool cleanup resin. It was also estimated that combustion of this material would release approximately 25% of the contamination (0.0275 millicuries) in a respirable form. Based on these assumptions, the licensees accident analysis estimated the total exposure to be 30 mrem, to which the external dose was a negligible contributor.

3.9.1.2Fire in Activated Graphite

The ARRR DP examines another scenario in Section 5.4.2, Fire in Activated Graphite, for a fire in activated graphite material that will be removed as part of the active decommissioning process. The activated graphite at the ARRR facility is approximately 2-feet by 2-feet by 4-feet in dimension, and for this scenario it was assumed that it would catch fire even though it is currently contained in aluminum. The graphite volume of 16 cubic feet was estimated to contain 1.41 curies of contamination based upon an independent activation analysis of this graphite material, which calculated a radionuclide inventory of Europium-152 (Eu-152) present at 93.3%

and Europim-154 (Eu-154) present at 6.5%, with other radionuclides representing less than 1%.

It was also estimated that combustion of this structural material would release approximately 25% of the contamination (0.325 curies) in a respirable form. Based on these assumptions, the licensees accident analysis estimated the total exposure to be 182 mrem, to which the external dose was a negligible contributor.

3.9.2 Release of Airborne Contamination

3.9.2.1Dropped and Damaged Ion Exchange Column

Section 5.4.3, Dropped Ion Exchange Column, of the ARRR DP states that an uncontrolled release of airborne radioactivity could occur during demolition activities involving contaminated or activated materials, such as the reactor pool water demineralizer. For this scenario, the licensee estimated that the reactor pool water demineralizer contains 3.3 cubic feet of resin and 79 millicuries of contamination based upon an independent laboratory analysis of the resin activity concentration. The worst-case accident scenario would be dropping the reactor pool water demineralizer resin column liner as it is being lifted out of the pool for disposal. Aerotest assumed that 1% of the activity of this column was respirable, and 10% of the respirable material escaped the column and became airborne during the postulated accident. Based on these assumptions, the licensees accident analysis estimated that the TEDE is less than 1 mrem, to which the external dose was a negligible contributor.

3.9.2.2Dropped Irradiated Hardware Liner

Section 5.4.4, Dropped Irradiated Hardware Liner, of the ARRR DP states that most of the activity in the reactor pool is contained in activated components that include control rods, instrument tubes, etc. Because cutting operations for these components will be performed underwater, no cutting accident releases were postulated. However, a liner filled with irradiated hardware could be dropped while it is lifted for placement into a shipping container. The licensee stated that the radioactivity in irradiated hardware is contained within the metal structure of the hardware item except for surface contamination, and it would be highly unlikely for a component in the liner to break. If an irradiated component did break, the diameters of any particles produced would be large enough that it is unlikely that the particles would remain airborne and be respirable. Accordingly, even though Aerotest does not consider it plausible that an accident involving a dropped irradiated hardware liner could result in measurable exposures at the ARRR site boundary, this scenario was evaluated because it includes the largest curie inventory, and therefore demonstrates that potential exposures to the public are acceptable even when worst-case accident assumptions are utilized.

For this scenario, a waste shipping liner containing 120 cubic feet of activated hardware was estimated to contain 1,460 curies of contamination based on the guidance contained in NUREG/CR-1756, Volume 1, Tables E.1-2, E.1 -3, E.1-5, and E.1-6, for a reference research

reactor. The worst-case accident scenario would be dropping the filled liner as it is being lifted out of the pool for disposal. Aerotest assumed that 1% of the activity of this liner was respirable, and 1% of the respirable material escaped the liner and became airborne during the postulated accident. Based on these assumptions, the licensees accident analysis estimated the total exposure to be 143 mrem, to which the external dose was a negligible contributor.

3.9.3 Transportation Accidents

Section 5.4.5, Transportation Accidents, of the ARRR DP provides the licensees assessment of transportation accident consequences. Various forms and quantities of radioactive waste will be shipped from the ARRR facility during the active decommissioning project. As stated in this section of the DP, the dose consequences from transportation accidents could be higher than the contamination accident scenarios described above because high-activity components could be involved. As such, there is a potential for a moderate dose consequence of between 1 and 25 mrem for the public following a transportation accident. However, the licensee concludes that adherence to NRC and DOT radioactive material packaging and transportation requirements is a sufficient control measure for mitigating transportation-related incidents.

3.9.4 Conclusion

According to the ARRR DP, the accident analysis shows that the postulated accident scenarios for the facility during active decommissioning would result in a TEDE to the nearest member of the public that is much less than the EPA's lower Protective Action Guide (PAG) limit of 1 rem (1,000 mrem), as stated in the Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, but for some scenarios is somewhat larger than the NRCs normal annual operational dose limits for individual members of the public of 0.1 rem/yr (100 mrem/yr) contained in 10 CFR 20.1301, Dose limits for individual members of the public. The ARRR DP further states that the results of the accident analyses show that potential offsite consequences from accidents are well below the EPA PAGs. Therefore, offsite emergency plans are not needed to address the potential consequences from the postulated accidents that could occur during the active decommissioning of the ARRR facility.

The NRC staff reviewed the postulated accidents identified in the ARRR DP and determined that because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2),

which allows for less detailed decommissioning planning while the facility is in storage and surveillance, this version of the ARRR DP is acceptable. However, as also required by 10 CFR 50.82(b)(2), a more complete description of the postulated accidents will be needed in the updated DP to determine if the ARRR postulated accidents and descriptions are consistent with the guidance provided in NUREG-1537, Part 2, Appendix 17.1, Section 3.3, Radiological Accident Analysis, pursuant to 10 CFR 50.82(b)(4)(ii). The licensee is required to provide a more detailed version of the ARRR DP before active decommissioning begins, which will be reviewed by the NRC as part of the overall approval process for the updated DP to ensure that it appropriately addresses these remaining postulated accident scenario concerns.

Specifically, the NRC staff notes that future updates to the ARRR radiological accident analyses should consider incorporating (1) additional information on the ARRR risk mitigation plans, including information that supports why they are sufficient to protect the public health and safety and (2) a discussion of why the release of contaminated liquids was not considered a plausible accident scenario for ARRR, or alternatively, a discussion of the potential consequences of such an accident or other plausible contaminated spill scenarios.

The NRC staff notes that the current postulated accidents are reasonable and reflect the accidents that could be expected during active decommissioning. According to the DP, the licensee will have removed the reactor fuel from the site before commencing active decommissioning of the ARRR facility, so the radiological consequences of these postulated accidents are significantly less than those accidents occurring during reactor operations. The licensee considered accidental exposures from fire in either a waste storage area or from activated graphite, release of airborne radioactivity from a dropped and damaged ion exchange column or dropped irradiated hardware liner, and transportation accidents. The licensee concluded that the potential dose from transportation accidents could be higher than for the other postulated accidents, but that the licensee will reduce this potential by following NRC and DOT radioactive material packaging and transportation requirements. The NRC staff agrees with this conclusion related to the postulated accidents during active decommissioning.

3.10 Proposed Final Status Survey Plan

When fuel is removed from the site, as described in the DP, and major decommissioning activities are no longer delayed, the licensee must submit an updated detailed DP that will include detailed plans for a set of measurements to verify that the remaining residual radioactivity can conform to the NRCs release criteria once reactor-related radioactivity has been reduced or removed.

The updated DP should include the proposed plan for performing these measurements, analyzing the results, interpreting the results, and relating those results to the release criteria for terminating the license. The licensee will generally submit these results in a comprehensive report to the NRC when it requests an NRC inspection confirming that the release criteria have been met. According to NUREG-1537, Part 2, Appendix 17.1, Section 4, Proposed Final Radiation Survey Plan, the FSS plan should address the following:

• Summary of the location and types of all residual radioactivity.

• Scope of methods to measure and determine the relevant radiological parameters, including background radiation.

• Discussion of methods, statistical or otherwise, to ensure that essentially all residual sources of radiation are found and quantified.

• List of instruments and discussion of measurement techniques used.

• Procedures for calibrating instruments to ensure reliability and accuracy.

• Methods of documenting results that are available, retrievable, and comprehensible.

The licensee states in Section 6.1, Proposed Final Radiation Survey Plan, of the ARRR DP that the purpose of the FSS is to demonstrate that the radiological condition of the ARRR structures is at or below the release criteria established for the facility and the site and meets the unrestricted use requirements as specified in 10 CFR 20.1402. The licensee will develop the FSS based on applicable guidance contained in NUREG-1575 (MARSSIM), NUREG-1757, Volume 2, and NUREG-1507, Minimum Detectable Concentrations with Typical Radiation Survey for Instruments for Various Contaminants and Field Conditions (ML20233A507), which will also be used as guidance for the FSS plan (FSSP). When developed, the FSSP will

incorporate the following major elements: (1) radiological contaminants, (2) DCGL summary, (3) survey areas and units, (4) survey methodology, (5) survey instrumentation, (6) survey design, (7) data assessment, and (8) quality control.

The licensee states that the FSS will be designed to demonstrate that licensed radioactive materials have been removed from the site to the extent that any remaining residual radioactivity is below the radiological criterion for unrestricted release. If the survey results pass the requirements of the FSSP, the survey unit will be suitable for unrestricted release. If the survey results do not meet the criteria and testing requirements as specified in the FSSP, additional investigation and remediation will be performed as required by the survey plan.

Additional investigations will include an evaluation of the survey design, instrumentation used, and the statistical evaluations, as necessary. According to the ARRR DP, the FSSP will follow the guidance provided MARSSIM to demonstrate compliance with the release criteria. The MARSSIM process emphasizes the use of data quality objectives, proper classification of survey areas (survey units), a statistically based survey and sampling plan, and an adequate quality assurance/quality control (QA/QC) program.

The NRC staff notes that the NRCs dose criterion for unrestricted release, as specified in 10 CFR 20.1402, is 25 mrem/yr from all dose pathways, and the NRC will approve the site-specific ARRR DCGLs to that level during the future review of the more detailed updated ARRR DP. More restrictive operational DCGLs can be applied, but do not require approval from the NRC. In addition, a lower dose limit may be established to meet state or other non-NRC requirements, but the NRC will evaluate the ARRR FSS data against the 25 mrem/yr all pathways dose criterion.

3.10.1 Identification and Classification of Survey Units

Section 6.1.1, Area Classification, of the ARRR DP states that all soils and building structures were assigned a classification based upon information collected during the HSA and measurements and sampling conducted during site characterization activities. The initial area classifications for the ARRR are provided Table 6-1, ARRR Initial Classifications, of the ARRR DP. There are two overall classifications: non-impacted and impacted. Non-impacted areas have no reasonable potential for residual contamination because there was no known impact from facility operations. According to Table 6-1 of the ARRR DP, there were no initial area classifications of non-impacted at the ARRR site.

Impacted areas may contain residual radioactivity from licensed activities and are further divided into Class 1, Class 2, or Class 3 designations, as follows:

• Class 1 areas are impacted areas that have or are expected to have concentrations of residual radioactivity that exceed the DCGL(s), or areas identified to have contamination in excess of the DCGL(s) prior to remediation.

• Class 2 areas are impacted areas that are not likely to have concentrations of residual radioactivity that exceed the DCGL(s).

• Class 3 areas are impacted areas that are not expected to contain residual radioactivity or contain residual radioactivity levels are a small fraction of the DCGL(s).

Class 1 areas receive the highest degree of survey effort because they have the greatest potential for contamination, followed by Class 2, then Class 3 areas. According to the ARRR

DP, when available information was not sufficient to designate an area as a particular class, the licensee defaulted to a classification for the area of Class 1. Areas that are considered to be on the borderline between classes received the more restrictive classification designation.

The licensee states that areas that have been classified based on contamination potential will be further divided into survey units. However, specific survey units are not defined in the current ARRR DP and will be defined in the FSSP. An FSS will be performed in each survey unit and the data evaluated to demonstrate compliance with the unrestricted release criterion. The NRC staff notes that the size of a survey unit is directly affected by its classification. Section 4.6, "Identify Survey Units, of MARSSIM provides suggested sizes for survey units.

Section 6.1.12, Remediation and Reclassification, of the ARRR DP states that after survey data has been collected, it may be necessary to remediate the entire survey unit or only a portion of it. The licensee states that if an individual survey measurement (scan or direct) in a Class 2 survey unit exceeds the associated DCGL, the survey unit, or portion of the survey unit, will be evaluated, and if necessary, reclassified to a Class 1 survey unit and the survey re-designed and re-performed accordingly. If an individual survey measurement in a Class 3 survey unit exceeds 25% of the associated DCGL, the survey unit, or portion of a survey unit, will be evaluated, and if necessary, reclassified to a Class 2 survey unit and the survey re-designed and re-performed accordingly.

3.10.2 Sampling and Measurements Approach

Section 6.1.4, Background Reference Areas, Section 6.1.9, Scan Coverage, Section 6.1.10, Reference Grid, and Section 6.1.11, Systematic Sampling and Measurement Locations, of the ARRR DP describe the method for establishing background radiation, as well as the provisions for scan coverage and location based on survey unit classification. The amount of area to be covered by scan measurements in each survey unit is based upon the survey unit classification as described in MARSSIM and Table A.2, Scanning Coverage Fractions and Scanning Investigation Levels, of NUREG-1757, Volume 2, and is summarized in Table 6-2, Scan Coverage, of the ARRR DP.

The licensee states that for Class 3 survey areas, biased surface scans will typically be performed on areas with the greatest potential of contamination. A reference grid will be used for reference purposes and to locate the sampling and measurement locations. Sampling and measurement locations for Class 1 and Class 2 survey units will be located in a systematic pattern or grid. The grid spacing will be determined using the methodology in MARSSIM, based upon the survey unit size and the minimum number of sampling or measurement locations. For Class 3 survey units, each sampling and measurement location will be randomly selected.

3.10.3 Radiation Survey Instrumentation

According to Section 6.1.13, Survey Instrumentation, of the ARRR DP, radiation detection and measurement instrumentation for the FSS will be selected to provide both reliable operation and with the best possible sensitivity to detect the radionuclides of concern (ROCs) established for ARRR. When possible, instrumentation selection will be made to identify the ROCs at levels sufficiently below the DCGL. Detector selection will be based upon detection sensitivity, operating characteristics, and expected performance in the field.

Commercially available portable and laboratory instruments and detectors that will be used to perform survey measurements and sample quantification may include:

• Surface scanning.

• Direct surface contamination measurements.

• Gamma spectroscopy analysis of soil and other bulk materials.

• Alpha spectroscopy analysis of soil and other bulk materials.

The ARRR DP states that radiation detection and measurement instrumentation will be selected based on the type and quantity of radiation to be measured. The instruments used for direct measurements will be capable of detecting the minimum detectable concentrations (MDC).

Instruments and detectors will be calibrated for the radiation types and energies of interest or to a conservative energy source. Instrument calibrations will be documented with calibration certificates and/or forms and maintained with the instrumentation and project records.

Calibration labels will also be attached to all portable survey instruments. Prior to using any survey instrument, the current calibration will be verified, and all operational source and background checks will be performed. Instrumentation used for FSS will be calibrated and maintained in accordance with approved calibration procedures. Radioactive sources used for calibration will be traceable to National Institute of Standards and Technology standards and be obtained in standard geometries to match the type of samples being counted.

Table 6-3, Laboratory Analysis Methods and Sensitivities, of the ARRR DP provides a list of typical laboratory analysis methods and the associated MDCs (sensitivities) expected for FSS for the site. Methods listed are standard industry methods from the EPA and the Environmental Measurements Laboratory. In addition, according to Section 6.1.17, Field Screening -

Capability of Detection at DCGL, of the ARRR DP, Table 5-1, Health Physics Equipment and Instrumentation, of the DP lists typical field instruments for performing in-process surveys. The same, or similar, instruments will be used during FSS. The typical MDCs are noted to be low enough to measure concentrations at the DCGL for field instruments used for scanning.

Upon completion of the decontamination and remediation activities, the licensee states that a FSS will be performed per the guidance described in MARSSIM. The results of the FSS will be summarized in a FSS report (FSSR), which will be submitted to the NRC.

3.10.4 Survey Design

According to Section 6.1.14, Survey Design, of the ARRR DP, survey measurements and sample collection will be performed by personnel trained and qualified in accordance with applicable decommissioning procedures. The techniques for performing survey measurements and collecting samples, such as chain-of-custody, will also be specified in decommissioning procedures. Both random and biased surveys will be performed. Biased surveys will be based on results of historical surveys, walkdowns, historical use of the area, areas remediated, characterization surveys, and professional judgment.

The types of survey methods to be employed in the ARRR FSS include:

• Gamma walkover surveys.

• Scanning and static total surface contamination measurements.

• Removable contamination (smear) surveys.

• Volumetric sampling.

• Soil surveys.

• Building structural surveys.

Section 6.1.18, Investigation Levels, of the ARRR DP states that during the FSS, any areas of concern identified during the survey activities will be investigated. This will include any areas identified during the scan survey, as well as any results identified during survey data post processing and review, that exceed the investigation levels. Based on this review, the licensee will address the suspect areas by further biased surveys and sampling as necessary. In Class 1 and Class 2 survey areas, the investigation level will be set at the scan MDC for scan surveys, and at the DCGL for direct measurement or sample results, to ensure elevated areas are identified. In Class 3 survey areas, the investigation level will be set at the scan MDC for scan surveys, and at 50% of the DCGL for direct measurement or sample results, based on the guidance contained in MARSSIM related to appropriate investigation levels.

3.10.5 The Final Status Survey Report

The licensee states in Section 6.2, Final Status Survey Report, of the ARRR DP that Aerotest will develop an FSSR when it completes the FSS of the ARRR site and submit the report to the NRC. The FSSR will provide a summary of the survey results and the overall conclusions to demonstrate that the ARRR site meets the radiological criteria for release. Information such as the number and type of measurements, basic statistical quantities, and statistical analysis results will be included in the report. The level of detail is to be adequate to clearly describe the ARRR FSS program and to certify the survey results.

According to the DP, the FSS planning, data, and assessment information will be compiled for each survey unit. The documentation will provide a complete and unambiguous record of the radiological status of each survey unit relative to the established DCGLs. The information provided will also allow for an independent evaluation by NRC of the FSS results at a later time, including a repeat survey, commonly referred to as a confirmatory survey.

According to the ARRR DP, the following list provides a summary of the information that will be provided in the ARRR FSSR, at a minimum:

• Overview of the results of the FSS.

• Discussion of changes that were made in the FSS from what was proposed in the approved ARRR DP.

• Description of the method by which the number of samples was determined for each survey unit.

• Number of measurements/samples performed/collected in the survey unit.

• Description of the survey unit, including maps of measurement and sampling locations showing random start systematic locations for Class 1 and Class 2 survey units, and random locations for Class 3 survey units.

• Discussion of remedial actions and unique features.

• Measured sample concentrations in units that are comparable to the DCGLs.

• Statistical evaluation of the measured concentrations.

• Judgmental and miscellaneous sample data sets reported separately from systematic data.

• Discussion of anomalous data, including areas of elevated direct radiation detected during scanning that exceeded investigation levels, or measurement locations in excess of the DCGLs.

• A statement that the survey unit satisfied the DCGLs, and the maximum survey result encountered, as necessary.

• Description of any changes in the initial survey unit assumptions relative to the extent of residual radioactivity.

• Description of how ALARA practices were employed to achieve final activity levels.

• If a survey unit fails, a description of the investigation process and a discussion of the impact of the failure on other survey units and the site in general.

3.10.6 Conclusion

The NRC staff has reviewed the ARRR DP and FSSP and concludes that the plan is acceptable under 10 CFR 50.82(b)(4)(iii) because this version of the DP was evaluated against the requirement 10 CFR 50.82(b)(2), which allows for less detailed decommissioning planning while the facility is in storage and surveillance. However, as also required by 10 CFR 50.82(b)(2), a more complete description of the FSSP will be needed in the updated DP to determine if the ARRR FSSP is consistent with the guidance provided in NUREG-1757, Volume 2, and MARSSIM for the planning and conduct of final status surveys in order for the NRC staff to make the public health and safety conclusions required pursuant to 10 CFR 50.82(b)(4)(iii). As previously stated, the licensee is required to provide a more detailed version of the ARRR DP before active decommissioning begins, which will be reviewed by the NRC as part of the overall approval process for the updated DP to ensure that it appropriately addresses these remaining FSS and FSSP concerns.

Specifically, the NRC staff notes that an updated version of the ARRR DP could include additional detail in the following areas to assist the NRC staff in review of the ARRR FSSP:

• Information on ROCs for each applicable media, including:

o Insignificant contributors.

o Surrogate ratios.

• Ground water and surface water residual radioactivity characterization.

• DCGLs for each media (consider the EPA maximum contaminant levels).

• The use of DCGLs for elevated measurement areas or area factors.

In addition, NUREG-1537, Part 2, Appendix 17.1, Section 2.2.2, Current Radiological Status of the Facility, states that the licensee should discuss the types and quantities of all radioactivity remaining at the facility. And NUREG-1757, Volume 2, Section 4.2.3.1.3, Information to be Submitted, states that the licensee should provide a description and justification of the survey measurements for affected media (for example, building surfaces, building materials (volumetric

contamination) contamination, surface soil, subsurface soil, surface water, groundwater, sediments, as appropriate). However, the NRC staff notes that the ARRR DP makes no mention of surface water or groundwater considerations for the ARRR site. Even if these dose pathways are not relevant to the site, the more detailed version of the ARRR DP should provide a brief discussion of why this is the case to justify removal of the groundwater and surface water pathways from the final dose scenario to demonstrate compliance with the release criteria.

3.11 Technical Specifications, Physical Security, and Emergency Preparedness

3.11.1 ARRR Technical Specifications

The proposed amendment to approve the ARRR DP contains no changes to the ARRR TS since Amendment No. 6, approved by letter dated December 6, 2021, modified the ARRR TS to remove the authority to operate the ARRR, to authorize possession-only of the reactor and fuel, and to remove operational requirements not needed for the possession-only status. Thus, the current ARRR TS are sufficient for the permanently shutdown ARRR facility and this less detailed DP does not change the operating status of the facility; therefore, no additional TS changes are needed at this time to reflect the safe storage period. However, the NRC is issuing a license condition to Aerotest related to the change process for the ARRR DP, as discussed in Section 3.12 and Section 3.13 of this SER. This condition will be added to the ARRR facility license as part of the amendment that approves the ARRR DP.

3.11.2 ARRR Physical Security Plan

In accordance with the possession-only license issued to Aerotest on December 6, 2021, the licensee shall maintain in effect and fully implement all provisions of the NRC-approved physical security plan, including amendments and changes made pursuant to the authority of Paragraph (p) of 10 CFR 50.54, Conditions of licenses. The approved security plan consists of the document, withheld from public disclosure pursuant to 10 CFR 73.21, Protection of Safeguards Information: Performance Requirements, entitled Security Plan for ARRR, dated September 28, 2020. Thus, the current ARRR physical security plan is sufficient for the permanently shutdown ARRR facility and this less detailed DP does not change the operating status of the facility; therefore, no additional changes to the physical security plan are needed at this time.

3.11.3 ARRR Emergency Preparedness Plan

Section 9.0, Emergency Plan, of the ARRR DP states that Aerotest maintains a Reactor Facility Emergency Plan for responding to emergencies at the ARRR site. The purpose of this plan is to minimize any emergency's effect on the public, personnel, reactor facility, and the environment surrounding the facility. The ARRR Emergency Plan was updated as part of the transition to the possession-only license status, and revised in accordance with 10 CFR 50.54(q)(3). Thus, the current ARRR Emergency Plan is sufficient for the permanently shutdown ARRR facility and this less detailed DP does not change the operating status of the facility; therefore, no additional changes to the emergency plan are needed at this time.

3.11.4 Conclusion

The NRC staff reviewed the ARRR DP with respect to the licensees proposed TS, physical security plan, and emergency plan provisions that will remain in place during the period of safe storage before the onset of active decommissioning of the ARRR facility. The NRC staff

concludes that these provisions satisfy the requirement of 10 CFR 50.82(b)(4)(v) regarding TS and physical security plan provisions in place during decommissioning because the licensees continuing commitments in these programs are consistent with the applicable NRC regulations and are adequate for the protection of public health and safety, as well as the protection of facility radiological material and the response to emergencies that may arise at the ARRR site.

In addition, the NRC staff notes that the ARRR TS, physical security plan, and emergency plan may be further updated once the fuel is removed from the ARRR site, as removal of spent fuel from the site would significantly reduce the potential for a significant release of radioactive material offsite, thereby allowing reductions to the required provisions in several of these areas.

Changes to the ARRR TS, physical security plan, and emergency plan should be pursued in accordance with the provisions of 10 CFR 50.90, Application for amendment of license, construction permit, or early site permit, 10 CFR 50.54(p)(2), or 10 CFR 50.54(q)(3), as applicable for the type and scope of the change, or 10 CFR 50.54(a)(3), if applicable, for future changes to the ARRR QA plan or provisions.

3.12 Changes to the Decommissioning Plan

Section 11, Changes to the Decommissioning Plan, of the ARRR DP specifies the DP change criteria related to actions that can be taken without prior NRC approval. The licensee describes criteria they would use to make changes to the ARRR DP so that the changes do not involve an unreviewed safety question and would not need NRC approval. The areas of review include (1) an increase in the probability of occurrence, or an increase in the consequences from, an accident or malfunction of equipment important to safety when compared to the situation previously evaluated in the sites safety analysis report (SAR); (2) the possibility for an accident or malfunction of a different type than previously analyzed in the SAR; or (3) the reduction in margin of safety as defined in the SAR.

Therefore, the licensee is not allowed to make a change to the ARRR DP without prior NRC approval that would alter the original intent of the plan or would involve a situation that may impact radiation safety or worker or public dose. Further, the licensee states that the changes to the ARRR DP made without NRC approval will be approved by the Aerotest President, with support from the ARRR RSC. The licensee also infers that if a significant change to the ARRR DP is required, the RSC will apply the test identified in 10 CFR 50.59 as it applies to non-power reactors. Should the RSC determine that the change is an unreviewed safety question, the licensee will obtain NRC approval prior to implementing the change. The guidance related to implementation of 10 CFR 50.59 at non-power reactors was recently updated in NRC Regulatory Guide 2.8, Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments, at Non-Power Production or Utilization Facilities, Revision 0, dated February 2022 (ML22020A292). The NRC staff notes that 10 CFR 50.59 continues to apply for Aerotest, pursuant to 10 CFR 50.59(b), because Aerotest is authorized to possess fuel at the ARRR under the possession-only license issued on December 6, 2021. However, 10 CFR 50.59(b) also limits the application of 10 CFR 50.59 to ARRR once the fuel is removed. Therefore, after the licensees proposed plan for removal of the fuel from the ARRR site, any changes to the ARRR DP are controlled through the change process described in the ARRR DP and the ARRR facility license as described in SER Section 3.13 below. The NRC staff also compared the licensees proposed change criteria to those listed in NUREG-1537, Part 2, Appendix 17.1, and has determined that the ARRR DP change criteria are generally consistent with the NRC guidance for application of 10 CFR 50.59, and would not significantly increase potential worker, public, or environmental consequences.

In addition, relative to the environmental considerations for approval of this DP, the NRC staff has determined that the ARRR DP can be approved under an amendment that meets the eligibility criteria for categorical exclusion as set forth in Paragraph (c)(9) of 10 CFR 51.22, Criterion for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review (see Section 5 of this SER). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with issuance of the amendment approving the ARRR DP. However, since any changes made to the ARRR DP have the potential to challenge the criteria for the categorical exclusion, changes should be evaluated for potential significant environmental impacts that have not previously been reviewed.

Similarly, since the NRC staff determined that the ARRR decommissioning financial assurance information satisfies the requirements of 10 CFR 50.82(b)(4)(iv) (see Section 3.14 of this SER),

due in part to the licensee providing an updated cost estimate for the chosen alternative for decommissioning, any changes to the ARRR DP should also be reviewed for the potential to detract from or negate the reasonable assurance that adequate funds will be available for decommissioning. Therefore, the NRC staff has determined that change review criteria related to decommissioning environmental impacts and financial assurance should also be incorporated into the change review criteria for the ARRR DP, and, together with the changes to the ARRR facility license to approve the DP, are acceptable and necessary to ensure that NRC approval for changes to the ARRR DP is required under the appropriate circumstances.

3.13 License Condition Associated with the ARRR Decommissioning Plan

To reflect approval of the ARRR DP, the NRC is amending the ARRR facility license to incorporate the approved DP and establish additional change review criteria for the DP for changes that can be made without prior NRC approval.

The associated ARRR license condition will read as follows:

The licensee shall implement and maintain in effect all provisions of the approved Decommissioning Plan for the Aerotest Radiography and Research Reactor, dated July 20, 2021, as supplemented on January 20, 2022, July 21, 2022, and November 16, 2022 (hereinafter the DP), which authorizes inclusion of the DP as a supplement to the Safety Analysis report pursuant to 10 CFR 50.82(b), and is subject to and amended by the following stipulations:

The licensee may make changes to the DP without prior NRC approval provided the proposed changes do not meet any of the following criteria:

• Require Commission approval under 10 CFR 50.59, Changes, tests, and experiments.

• Result in the potential for significant environmental impacts that have not previously been reviewed.

• Detract or negate the reasonable assurance that adequate funds will be available for decommissioning.

In addition, the associated decommissioning license condition will read as follows:

This DP is approved under the regulation in 10 CFR 50.82(b)(2), which allows for the planning for major dismantlement activities in the DP to be less detailed when these activities are delayed by first placing the facility in storage. An updated detailed DP must be submitted and approved prior to the start of major dismantlement activities. The updated DP shall contain more detailed information on site characterization, the remaining dismantlement and remediation activities, as well as the final status survey plan, for NRC review and approval prior to conducting final status surveys for license termination. Approval of this less detailed DP is not binding on the NRCs determination of the specific adequacy of the updated detailed ARRR DP.

3.14 Estimated Costs of Decommissioning

Section 3.2.2, Estimated Cost, of the ARRR DP states that the decommissioning cost estimate is $2,879,276, and Aerotest summarizes the costs in Table 3-3, Decommissioning Cost Summary - ARRR, of the ARRR DP. The estimate includes costs for decommissioning planning, mobilization, and management; dismantlement and decontamination of several facility structures and outdoor areas; shipping and disposal of waste; and site decommissioning and FSS, including the costs of an NRC confirmatory survey and other oversight and licensing expenses. Aerotest includes a contingency of 25% in the decommissioning cost estimate as recommended in NUREG-1757, Volume 3, Financial Assurance, Recordkeeping, and Timeliness, Revision 1 (ML12048A683), Section A.3.1, Preparing the Site-Specific Cost Estimate, to ensure that sufficient funds are available to cover costs that may result from unanticipated conditions or unforeseeable elements in the project scope. The NRC staff finds that unanticipated conditions or unforeseeable elements may include factors such as waste disposal rates or waste volume increases from undiscovered contamination. In addition, the time interval between the development of the current version of the ARRR DP and the start of active decommissioning activities can influence the costs associated with changes in the economy and regulatory requirements.

Additionally, during its review, the NRC staff recognized the decrease in the decommissioning cost estimate for ARRR from $3,080,126 in 2019 to $2,879,276 in 2021. In reviewing the decrease in the cost estimate, the NRC staff noted that Aerotest explains that the decrease is attributable to the fact that some elements of the 2019 cost estimate are no longer relevant.

Aerotest provides examples of these elements, including decreases in low-level waste material, non-radioactive debris, and labor costs, as well as the repurposing of nonactivated or uncontaminated shielding blocks that would otherwise be disposed of at a low-level waste disposal site. Considering these factors, as well as a more focused and detailed review of the cost estimate provided by Aerotest, the NRC staff finds that the decrease in the decommissioning cost estimate is reasonable.

With respect to the availability of funds to radiologically decommission ARRR, the DP states that Aerotest is committed to providing the funding for decommissioning of the ARRR. In its response to a request for additional information related to the current availability of funding, Aerotest states that a trust fund meeting the 10 CFR Part 50 requirements represents the legal document that describes the administrative and financial controls and protections to ensure funds are available for decommissioning activities, and that current funds in the trust fund exceed both the 2019 and 2021 decommissioning cost estimates for ARRR.

When considering the affirmation by Aerotest that funds in the decommissioning trust exceed the current decommissioning cost estimate, the NRC staff notes that in accordance with the provisions of the license transfer granting Aerotest possession of the ARRR license, which was approved by the NRC on February 28, 2017 (ML16333A448) and effective on July 17, 2017 (ML17138A310), the financial resources to decommission the facility were established and include:

• The sum total of $3,376,030 in a decommissioning trust fund for ARRR, which is greater than both the 2019 and 2021 decommissioning cost estimates for ARRR.

• The sum of $748,000 in a segregated account in the decommissioning trust fund for the disposal of the facility's nuclear fuel elements pursuant to DOE Contract DE-CR01-83NE4484, as amended.

• The sum of $625,000 in a segregated account in the decommissioning trust fund intended to fund the acquisition of fuel element storage casks.

• The sum of $1,125,000 in a segregated account in the decommissioning trust fund that manages the nuclear fuel elements after permanent cessation of the facility's operations and before acceptance of the fuel by the DOE.

• The sum of $300,000 available in an Irrevocable Letter of Credit to cover any shortfalls in decommissioning funding.

These provisions, which include both funding for radiological decommissioning and spent fuel management, provide reasonable assurance that funding will be available to complete the radiological decommissioning of ARRR and the management of spent fuel on site until DOE removal and disposition of the fuel.

To confirm that the licensee will continue to review and adjust, as necessary, the decommissioning funding levels, and in accordance with 10 CFR 50.82(b)(4)(iv), NRC sent an e-mail to the licensee (ML24039A156). The licensee stated (ML24039A171) that Aerotest will continue to comply with those requirements.

3.14.1 Conclusion

The NRC staff has reviewed the licensees decommissioning cost estimate and funding availability statement in the ARRR DP. Based on this review, the NRC staff concludes that the provision of this information satisfies the requirements of 10 CFR 50.82(b)(4)(iv) because the licensee has provided an updated cost estimate for the chosen alternative for decommissioning, the licensee has stated that it has received full funding for this estimate, and the licensee has provided a plan for assuring the availability of adequate funds by committing that Aerotest will provide the appropriate funds to decommission the ARRR facility.

3.15 Additional NRC Staff Observations for Future Detailed ARRR DP Updates

In addition to the NRC staff notes provided throughout this SER, the staff offers these additional observations to consider when the licensee provides the more detailed revision to the ARRR DP that will be submitted before active decommissioning begins, in accordance with 10 CFR 50.82(b)(2). Addressing these items, as well as those mentioned previously, in the

updated ARRR DP will add efficiencies to the future decommissioning interactions between Aerotest and the NRC staff.

1) The NRC staff noted that a spill involving a capsule of Sodium-24 (Na-24) was documented in the HSA provided for the ARRR facility, but not included in the ARRR DP as a source of potential radioactive contamination to be addressed or remediated during the decommissioning process. Specifically, the ARRR HSA states: A capsule of Na-24 was spilled at the south end of the facility before carpet was laid in the area. The spill was cleaned up immediately after it occurred. The licensee should consider including additional detail regarding this Na-24 spill, or information on the effectiveness of the cleanup activities, to the site characterization and radiological contamination information provided in the facility operating history section of the future ARRR DP.

2) The ARRR Site Characterization Report states that the complete analytical results used to establish the radionuclide summary in Table 4-1 of the ARRR DP, which was based on the radiological analysis of a spent demineralizer resin sample, can be found in Appendix A of the characterization report. However, this data does not appear to be included in Appendix A of the ARRR Site Characterization Report. The licensee should consider including these analytical results in the site characterization information provided to support the future revision to the ARRR DP. This information will be important to the NRC staff in evaluating the list of expected radionuclides during the active decommissioning phase of the ARRR.

3) Section 4.3.1.1.2 of the ARRR DP states that equipment, materials, instrumentation, and tools that are used or encountered during active decommissioning will be surveyed and released as clean waste only if the residual radioactivity is less than the current site release limits of 200 dpm/100 cm2 measurable beta contamination above background radiation and 30 dpm/100 cm2 measurable alpha contamination above background. It is not clear where these site release limits for the ARRR are established, nor are they consistent with the release limits described in NUREG-1537, Part 1, Section 17.1.4, Release Criteria and Final Survey. The licensee should consider clarifying where these limits were established from and what the current release limits are for the ARRR facility and site in the future revision to the ARRR DP.

4) The future revision of the ARRR DP should include an update to the decommissioning cost estimates based on current activity/conditions at the facility and be in current year dollars. Additionally, the licensee should update the decommissioning trust fund information in any future revision of the ARRR DP.

5) The future revision of the ARRR DP should include an updated Environmental Report with information that is current within 2 years of the submittal of the DP and that follows the guidance in NUREG-1748, Environmental Review Guidance for Licensing Actions Associated with NMSS Programs (ML032450279).

4.0 PUBLIC NOTIFICATION AND PUBLIC PARTICIPATION

Pursuant to the requirements in 10 CFR 20.1405, the NRC staff provided notification of the availability of, and solicited comments on, the ARRR DP from: the State of California Agreement State Director and State Liaison Officer; the Contra Costa County Board of Supervisors and County Administrator; the City of San Ramon Mayor, City Council, and City Manager; and the City of Danville Mayor, Town Council, and Town Manager. No Indian Nation or other indigenous

people that have treaty or statutory rights that could be affected by the decommissioning of the ARRR facility could be identified. In addition, the staff published a notice in the Federal Register (88 FR 48919) and a local newspaper, and contacted a representative of a local organization, regarding the availability of the ARRR DP and to solicit comments on it from other potentially affected parties and the public. No comments on the ARRR DP were received.

Regulations in 10 CFR 2.105(a)(3) state that a notice of proposed action for an amendment of a license is required for a facility that involves significant hazards consideration. What constitutes an amendment with significant hazards consideration is given in 10 CFR 50.92(c). For non-power production and utilization facilities (NPUFs) licensed under 10 CFR 50.21(c) that are also not testing facilities, such as ARRR, the NRC site project manager decides if the requested amendment constitutes a significant hazards consideration.

Based on a review of the ARRR application, regulation in 10 CFR 50.92(c), and applicable guidance on what constitutes a significant hazard consideration for NPUFs found in LIC-101 Appendix C, Guide for Processing License Amendments for Non-Power Production and Utilization Facilities Revision 0, (ADAMS Accession No. ML19248C539) and NRC Regulatory Issue Summary 2001-22 (ADAMS Accession No. ML011860215), NRC staff finds that because the ARRR DP is permanently shutdown and the fuel is permanently removed from the reactor and in storage, as required by the POL, approving the DP by amendment involves no significant hazards consideration because it does not involve a significant increase in the probability or consequences of an accident previously evaluated, create the possibility of a new or different kind of accident from any accident previously reviewed, or involve a significant reduction in a margin of safety. Therefore, publication prior notification of this amendment pursuant to 10 CFR 2.105, Notice of Proposed Action, is not required as noted in the finding in the License Condition above.

Pursuant to 10 CFR 2.106, Notice of Issuance, publication of a notice of issuance is not required for an amendment of a license for a facility licensed under 10 CFR 50.21(c) which is not a testing facility as defined in 10 CFR 50.2.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment associated with the ARRR DP changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. Based on the review of the ARRR DP discussed above, the NRC staff has determined that the amendment involves no significant hazards consideration, no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment to approve the current version of the ARRR DP.

6.0 CONCLUSION

The NRC staff has reviewed the licensees proposed actions to plan for decommissioning of the ARRR, and to perform an FSS, once the reactor fuel has been removed from the site. The ARRR DP was reviewed to ensure that: (1) the DP shows that the licensee identified the technical and regulatory requirements to dismantle the reactor facility safely; (2) the licensee

has described in the DP methods to dispose of radioactivity from reactor operation that are acceptable; and (3) the DP shows that the licensee has the resources to complete the decommissioning so that the NRC can consider release of the facility once contamination levels have been adequately remediated to levels commensurate with unrestricted use in accordance with 10 CFR 20.1402.

In accordance with 10 CFR 50.82(b)(2), Aerotest submitted a less detailed version of the ARRR DP because the site decommissioning plans involve a delay of the major dismantlement activities by first placing the facility in storage. Updated detailed decommissioning plans shall be submitted by Aerotest and approved by the NRC prior to the start of active decommissioning activities at the ARRR after the licensees proposed plan of fuel removal from the site. As a result, several of the areas in the ARRR DP did not provide a level of detail that allowed the NRC staff to make definitive final decisions about the ability of specific aspects of the Aerotest decommissioning plans to meet the applicable requirements and regulatory guidance for license termination.

However, the NRC staff was able to use the information provided in the ARRR possession-only license and the DP to establish that the licensee was adequately prepared to enter a period of safe storage. Specifically, as discussed in the safety evaluation associated with the ARRR POL amendment, dated December 6, 2021, long term storage of spent fuel at the facility is considered adequate to provide reasonable assurance of public health and safety and the environment. This conclusion is based, in part, on the information provided by the licensee relative to the systems and procedures that will continue to be used to ensure that long term storage of the ARRR fuel is safe over the projected storage period discussed in the DP.

In addition, the ARRR DP was submitted to the NRC prior to the issuance of a license amendment that changed the ARRR facility license to reflect a possession-only status for the facility. Accordingly, the NRC staff notes that the requirements of the POL take precedence over any outdated or conflicting statements in the ARRR DP related to specific site programs or requirements. For the purposes of this SER, the NRC staff conducted its review of the ARRR DP based on the licensing basis established by the ARRR POL.

Based on the NRC staffs review of the licensees application for approval of the ARRR DP, the NRC staff finds that the licensee is adequately cognizant of its continuing responsibilities to protect the health and safety of both workers and the public from undue radiological risk. The licensee provided reasonable assurance that Aerotest will dismantle the reactor and dispose of all significant reactor-related radioactive materials safely and in accordance with applicable regulations and NRC guidance, including applicable state, DOT, and DOE requirements.

The NRC staff concludes that the licensees chosen method for decommissioning - a period of safe storage with fuel onsite followed by an updated and approved detailed DP, then active decommissioning, decontamination, and dismantlement once the fuel has been permanently removed from the reactor building - is acceptable and meets the requirements of 10 CFR 50.82(b)(4)(i). The NRC staff also concludes that the licensee provided acceptable organizational structure and control to decommission the ARRR while maintaining due regard for protecting the public, the environment, and workers from significant radiological risks.

Furthermore, the NRC staff concludes that the licensees general description of the plan for radiation protection and radioactive material and waste management is acceptable based on the use of standard guidance and practices for such programs. The NRC staff also finds that the personnel training program that Aerotest proposes is acceptable because its scope covers all

aspects of the future decommissioning activities that need to be performed safely. The industrial safety program and procedural and equipment controls are consistent with such programs at decommissioning reactors, and they are therefore acceptable.

Except as otherwise discussed in this SER, the NRC staff concludes that the accident analyses for the ARRR show potential radiological consequences to be well within acceptable limits. In addition, the NRC staff concludes that the ARRR DP contains a description of the controls and limits on procedures and equipment to protect occupational and public health and safety as required by 10 CFR 50.82(b)(4)(ii) when reviewed as a less detailed plan pursuant to 10 CFR 50.82(b)(2). The NRC staff also concludes that, except as noted in this SER, the licensee has adequately described the radiological status of the ARRR, as well as acceptably described the tasks, the sequence of activities, and the schedule needed to decommission the ARRR. Therefore, the NRC staff concludes that the licensee has provided an acceptable general overview and description of its planned final radiation survey as required by 10 CFR 50.82(b)(4)(iii) when reviewed as a less detailed plan pursuant to 10 CFR 50.82(b)(2).

The NRC staff concludes that the licensee has provided, in accordance with 10 CFR 50.82(b)(4)(iv) when reviewed as a less detailed plan pursuant to 10 CFR 50.82(b)(2),

an acceptable updated cost estimate for the chosen decommissioning option and has an acceptable plan for assuring the availability of adequate funds for the completion of decommissioning of the ARRR facility in the future. This includes additional information regarding financial assurance that sufficient funds will be available to complete the decommissioning activities at the end of the ARRR storage period.

The NRC staff concludes that the licensee has provided an acceptable description of the TS, QA provisions, emergency planning, and physical security plan provisions that will be in place during active decommissioning. Therefore, the NRC staff concludes that the ARRR DP meets the requirements of 10 CFR 50.82(b)(4) when reviewed as a less detailed plan pursuant to 10 CFR 50.82(b)(2).

Based on the above considerations, the NRC staff concludes that the ARRR DP demonstrates that the future active decommissioning activities, once fully described in a more detailed update to the DP, will provide reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner. The decommissioning activities will be performed in accordance with NRC regulations and will not be inimical to the common defense and security or the health and safety of the public. Additionally, as previously stated, the NRC has published a notice of the availability of the ARRR DP to interested persons and solicited comments. Therefore, in accordance with 10 CFR 50.82(b)(5), the NRC approves the ARRR DP by amendment, subject to the criteria in Section 2.F of the ARRR facility license.

Principal Contributors: Nathan Fuguet, NMSS Marlayna Doell, NMSS Shawn Harwell, NMSS Jack Parrott, NMSS Date: March 6, 2024

ml23310a104; Ltr ML23310A112

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NAME JParrott JPAGendelman AG SAnderson SA JMarshall JM DATE Nov 7, 2023 Mar 4, 2024 Mar 5, 2024 Mar 6, 2024