IR 05000113/2011001
| ML11187A017 | |
| Person / Time | |
|---|---|
| Site: | 05000113 |
| Issue date: | 07/05/2011 |
| From: | Spitzberg D NRC Region 4 |
| To: | Offerle R Univ of Arizona |
| References | |
| IR-11-001 | |
| Download: ML11187A017 (14) | |
Text
July 5, 2011
SUBJECT:
NRC INSPECTION REPORT 050-00113/11-001
Dear Mr. Offerle:
This refers to the NRC inspection conducted on June 21-24, 2011, at the University of Arizonas research reactor in Tucson, Arizona. This inspection was an examination of activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license. Within these areas, the inspection consisted of selected examination of procedures and representative records, observations of activities, and interviews with personnel. The enclosed report presents the results of this inspection. No violations were identified, and no response to this letter is required.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response, should you choose to provide one, will be made available electronically for public inspection in the NRC Public Document Room or from the NRCs document system (ADAMS), accessible from the NRCs Web site at http://www.nrc.gov/reading-rm/adams.html. To the extent possible, your response should not include any personal privacy, proprietary, or safeguards information so that it can be made available to the Public without redaction.
Should you have any questions concerning this inspection, please contact Mr. Robert Evans, Senior Health Physicist, at (817) 860-8234 or the undersigned at (817) 860-8191.
Sincerely,
/RA/
D. Blair Spitzberg, PhD, Chief
Repository and Spent Fuel Safety Branch Docket: 050-00113 License: R-52
Enclosure:
NRC Inspection Report 050-00113/11-001
UNITED STATES NUCLEAR REGULATORY COMMISSION R E GI ON I V 612 EAST LAMAR BLVD, SUITE 400 ARLINGTON, TEXAS 76011-4125
University of Arizona
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REGION IV==
Docket:
050-00113
License:
R-52
Report:
050-00113/11-001
Licensee:
University of Arizona
Facility:
Research Reactor
Engineering Building (20)
Location:
Tucson, Arizona
Dates:
June 21-24, 2011
Inspector:
Robert J. Evans, PE, CHP, Senior Health Physicist
Repository and Spent Fuel Safety Branch
Approved by:
D. Blair Spitzberg, PhD, Chief
Repository and Spent Fuel Safety Branch
Attachment:
Supplemental Inspection Information
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EXECUTIVE SUMMARY
University of Arizona Research Reactor NRC Inspection Report 050-00113/11-001
Site Status
- The licensee was actively decommissioning the research reactor room during the inspection. All components had been removed from the reactor tank including the former reactor core. The licensees contractor recently sampled the tank wall and the soil surrounding the tank to determine how much neutron-activated radioactivity will have to be removed for disposal. Following completion of decommissioning, the contractor will perform a final status survey to verify that the rooms previously supporting reactor operations have been decontaminated and can be free-released.
Research and Test Reactor Decommissioning
- The licensee and its contracted work force were conducting decommissioning activities in accordance with the NRC-approved decommissioning plan (Section 1.2.a).
- The licensee established sufficient procedure guidance to control site decommissioning activities. Site staffing was in compliance with technical specification requirements. The licensees final status survey plan was in general agreement with NRC guidance (Section 1.2.b).
- The NRC inspector conducted a survey in two rooms located above the former reactor to determine if these two areas were free of licensed radioactive material. The measured radioactivity levels were below the criteria for unrestricted release specified in the NRC-approved decommissioning plan. The licensee plans to conduct its final status survey of these two rooms in the near future (Section 1.2.c).
- The licensee established radiation protection, effluent monitoring, and emergency response programs in accordance with license and regulatory requirements (Section 1.2.d).
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Report Details
Site Status
The University of Arizonas TRIGA research reactor commenced operations during December 1958. The reactor was licensed to operate at a 110-kilowatt (thermal) steady state power level with a peak power of 650 megawatts. The reactor permanently shut down on May 18, 2010.
The fuel was removed from the core during May 2010, and the fuel was permanently transferred from the site during December 2010.
A contractor commenced with decommissioning activities during mid-May 2011. The contractor removed all major components from the reactor tank including instrumentation and piping, cooling coils, and reactor core. The licensee then sampled and discharged the pool water into the city sewer as allowed by regulations.
During the inspection, the licensees contractor collected core samples from the tank wall to determine the depth of neutron-activated radioactivity. The samples included the tanks gunite, steel liner, concrete and surrounding soil. The sample results were not available at the conclusion of the onsite inspection. The licensee will use these sample results to determine how much material will be removed from the walls of the tank for disposal.
Immediately after the onsite inspection, the contractor will begin removing all gunite material from the reactor tank wall since this material was in direct contact with the pool water. In support of this work, the contractor plans to install a containment system since this work will create the potential for airborne particulates. After the gunite material has been removed, the contractor plans to remove portions of the steel liner, concrete, and soil material as necessary based on the core sample results. Following the removal of the activated wall and soil material, the licensee plans to conduct general cleanup work in the reactor room and adjacent storage room. All residual radioactive material will be packaged for shipment to an out of state disposal facility.
As a final step in the decommissioning process, the contractor will conduct a final status survey of the five rooms associated with reactor operations. The contractor plans to conduct the final status survey during August 2011. Following the completion of the final status survey, the licensee plans to submit the survey results to the NRC for review and approval.
Research and Test Reactor Decommissioning (69013)
1.1 Inspection Scope
The purpose of the inspection was to determine if dismantlement and decontamination activities were being conducted safely and in accordance with regulatory requirements, licensee commitments, and the NRC-approved decommissioning plan.
1.2 Observations and Findings
a.
Decommissioning Activities
By letter dated May 21, 2009, the licensee submitted a proposed decommissioning plan to the NRC. The licensee supplemented the decommissioning plan by letter dated March 26, 2010. The NRC reviewed and subsequently approved the decommissioning
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plan by Amendment 20 to the license dated April 15, 2011. Five rooms are included in this decommissioning project: control room, reactor room, equipment storage room, and two rooms located directly above the reactor room. The inspector observed work in progress, interviewed site staff, and reviewed records. In summary, the inspector concluded that the licensee was conducting decommissioning in accordance with the NRC-approved decommissioning plan.
During 2010, the licensees contractor conducted core sampling around the reactor tank to obtain concrete and soil samples. The contractor collected these samples to determine if the subsurface area around the tank contained activated or contaminated concrete and soils. However, core sampling was suspended when an underground sewer pipe was breached. The results of these limited core sampling efforts were reported to the NRC in the post-shutdown characterization report dated October 13, 2010.
License Condition 2.B(3) allows the licensee to possess a 5-curie sealed americium-241 beryllium neutron source. During March 2011, the licensee removed its americium-beryllium sealed source from the reactor tank. The licensee transferred this sealed source to its radioactive materials storage facility. The inspector confirmed that the sealed source was in secure storage in the facility. The licensee eventually plans to transfer the sealed source to an authorized recipient, although the final destination of the sealed source had not been determined at the conclusion of the onsite inspection.
The licensee obtained the services of a contractor to conduct most decommissioning activities. Decommissioning commenced during May 2011. At the time of this inspection, the following components had been removed from the reactor tank: fuel storage racks and fuel holsters on the tank wall; instrumentation and irradiation tubes including radiation detectors, fission chambers, and ion chambers; cooling coils; beam and fast irradiation tubes; graphite thermalizer block; and all reactor components.
Following the removal of all components located within the reactor tank, the licensee disposed of the pool water. The pool volume was estimated to be between 4,000 to 5,000 gallons of water. The licensee sampled the water before and after core removal.
The licensee analyzed the two samples for gamma-emitting radionuclides and tritium (hydrogen-3) concentrations. The inspector reviewed the samples results. No gamma-emitting radionuclides were identified in the two samples. The samples contained measurable quantities of tritium, but the concentrations were well below the NRCs release limits. The tritium concentration in the pool water prior to core removal was 2269 picocuries per liter, while the concentration after core removal was 2300 picocuries per liter. These sample results were well below the NRCs sewer release limit of 10,000,000 picocuries per liter as specified in 10 CFR Part 20, Appendix B, Table 3.
Based on these two sets of gamma and tritium sample results, the licensee subsequently released the liquid into the university sewer as allowed by 10 CFR 20.2003. The release was conducted on June 14-16, 2011.
Following disposal of the tank water, the contractor collected samples from the reactor tank wall to determine the depth of neutron-induced activation of the wall materials.
These samples were collected, in part, to supplement the subsurface characterization sampling results that were submitted to the NRC by report dated October 13, 2010. The contractor collected six core samples: one vertical sample and five horizontal samples.
The samples included gunite, steel liner, concrete, and soil material. The radionuclides
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of concern included europium-152, europium-154, and cobalt-60. The sample results were not available at the end of the onsite inspection. The amount of material to be removed from the tank wall depends on the results of these six core samples.
b.
Work Controls
The organization and staffing requirements are described in Technical Specifications (TS) Section 6.1. The inspector compared the current organization to the structure provided in TS. Key positions designated in TS have been filled, and sufficient staff were available to conduct the work. The staff included the reactor operations staff, contractors, and licensee support staff. The licensee established a reactor committee in accordance with TS 6.2. The committee met at least quarterly. The licensee also established a quality assurance program for fuel removal and shipment activities, and the licensee continued to maintain a quality assurance program that included routine audits.
The inspector reviewed the work plans for the decommissioning work and discussed the work plans with contractor staff. The contractor was conducting the work under four work plans: facility preparation, reactor component dismantlement, concrete/soil removal, and facility restoration. The inspector concluded that the work plans provided sufficient instructions for conducting the decommissioning activities.
Two of the four work plans were still in draft during the inspection. The unapproved work plans included the concrete/soil removal and facility restoration work plans. These documents were in draft, in part, because the work to be conducted depends on the results of the recently collected tank wall core samples. The results of core sampling will be used to identify the tank wall material that will have to be removed. The quantity of material removed also has an impact on the tank wall bracing requirements that will have to be constructed for worker protection. The licensees reactor committee is expected to review and approve these two work plans prior to implementation.
The licensee still had radioactive material and wastes in storage pending completion of decommissioning. At the time of the inspection, some material was still in storage in the equipment storage room adjacent to the reactor room. In addition, the reactor core was in storage at the licensees radioactive material storage facility. The inspector toured the equipment storage room and the storage facility. The licensee was maintaining security of the stored material in accordance with the requirements of 10 CFR 20.1801.
Following completion of decommissioning, the licensee plans to package and ship all waste material to an out-of-state disposal site.
License Condition 2.C(4)c requires the licensee to submit a final status survey plan to the NRC. The plan was submitted by letter dated May 25, 2011. The inspector reviewed the final status survey plan and discussed the plan with the licensees representative. The inspector noted that the plan did not clearly discuss investigation levels and surveys of the sink, drain, and ventilation systems. The NRC project manager is expected to submit additional comments about the plan to the licensee.
Changes to the plan will require reactor committee approval prior to implementation.
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c.
NRC Survey
The NRC inspector conducted limited surveys to determine if two areas listed in the license were free of radioactive materials. The inspector conducted surveys of Rooms 216 and 216A. These two rooms are located above the reactor room. The two rooms were originally designed to receive a beam of neutrons from the reactor. A 9-inch beam port penetrates the floor of Room 216 directly above the reactor core. The licensees records suggest that this room was not used for neutron beam experiments.
Instead, the room was used for storage of reactor supplies and departmental records.
The licensee previously submitted a post-shutdown radiological characterization report to the NRC. This report described the radionuclides of concern for this decommissioning project. The radionuclides of concern included tritium and various beta-gamma emitting radionuclides. Based on the results of the characterization report and reactor operating history, the licensee concluded that alpha-emitting radionuclides were not a concern at this facility.
The inspector conducted ambient gamma radiation measurements, surface scans, and fixed-point measurements. In addition to the fixed-point measurement of beta-emitting radionuclides, the inspector elected to measure for the presence of alpha-emitting radionuclides on room surfaces. Based on the as-found sample results, the inspector elected not to collect swipe samples for removable alpha-beta contamination. Also, the inspector did not collect swipe samples for detection of removable tritium contamination due to its low health hazard. The NRC may elect to collect swipe samples for removable tritium contamination during a future inspection.
Prior to conducting the survey, the inspector collected background measurements in Room 111 of the engineering building. Room 111 is an administrative office that was used by the licensee for its background measurements. Based on these background measurements, the inspector calculated a lower limit of detection (LLD) for surface contamination. Any fixed point sample result greater than the LLD could be representative of contamination. Any sample result below the LLD was considered to be indistinguishable from background levels.
After measurement of background ambient gamma radiation levels, the inspector conducted gamma radiation surveys in Rooms 216 and 216A. The ambient gamma radiation surveys were conducted using a Ludlum Model 19 microRoentgen survey meter (NRC number 016337, calibration due date of 1/3/12, calibrated to cesium-137)
and a Ludlum Model 12 count rate meter (NRC number 20888G, calibration due date of 10/25/11, calibrated to cesium-137) coupled to a Model 44-10 sodium iodide probe.
With a background of 15 microRoentgens per hour, the two rooms ranged from 18-26 microRoentgens per hour using the Model 19 survey meter. With a background of 12,000 counts per minute (cpm), the two rooms ranged from 12,000-19,000 cpm. The highest ambient gamma radiation levels in both rooms were measured adjacent to the brick walls in the rooms. The inspector attributed the elevated gamma radiation levels to naturally occurring radioactive material in the bricks. The decommissioning plan does not provide a release limit for gamma radiation level, and the measurements were taken primarily to locate areas of elevated radioactive contamination.
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The inspector conducted scans and fixed point measurements of the room surfaces using an Eberline E-600 survey meter (NRC number 063473, calibration due date of 2/28/12, calibrated to technicum-99 and plutonium-239) coupled to a SHP380AB alpha-beta probe. The inspector scanned selected areas of the room including the beam port and floor cracks. The inspector also collected 30 fixed-point measurements in the two rooms. With a background of 4.74 cpm for alpha particulates, no direct measurements exceeded the survey meter LLD of 17.9 cpm. With a background of 248 cpm for beta particulates, 10 of 30 measurements exceeded the survey meter LLD of 325 cpm. The highest direct beta particulate measurement was 177 cpm above background, or 2528 disintegrations per minute per 100-square centimeters (dpm/100 cm2) above background. This sample result was comparable to the licensees highest sample result of 2772 dpm/100 cm2, as documented in the post-shutdown characterization report dated October 13, 2010. Although the inspector attributed these elevated measurements to naturally occurring radioactive material in the building construction material, all measurements were still below the licensees derived concentration guideline level of 7100 dpm/100 cm2.
In summary, the survey results suggest that Rooms 216 and 216A did not contain alpha particulate contamination. The beta particulate contamination was less than the NRC-approved derived concentration guideline level provided in the decommissioning plan and final status survey plan. The inspector concluded that the radioactivity identified in the two rooms was most likely attributable to naturally occurring radioactive material and not licensed radioactive material. Finally, the licensee plans to conduct the final status survey in these rooms in the near future. The results of the final status survey will be submitted to the NRC for review and approval at a later date.
d.
Radiation Protection Program Review
The inspector reviewed the licensees radiation protection program including occupational exposures to radioactivity. The licensee issued dosimeters to monitor for external exposures and conducted air sampling to monitor for internal exposures. The licensee discontinued the collection of bioassay samples during 2004.
The inspector reviewed the licensees occupational exposure records for 2010 because the licensees staff supported fuel movement activities during 2010. None of the licensees staff received greater than 10 millirems of exposure during 2010. In addition, the highest exposure for the defueling project staff was 14 millirems. These assigned exposures were well below the 5000 millirem total effective dose equivalent limit specified in 10 CFR 20.1201(a).
The licensee originally estimated that the collective occupational exposure for the decommissioning effort would be 2.39 person-rems (2390 person-millirems).
Decommissioning activities commenced during May 2011. At the time of the inspection, the exposure records for May 2011 were available for review. The licensees records indicate that the contractors staff received undetectable levels of external exposure during May 2011. The licensee and the contractor collected air samples to monitor for internal exposures to radioactivity. No internal doses were assigned because no airborne radioactivity was identified in these air samples above background levels.
Whole body dosimeters and finger rings were assigned to workers in June 2011 to
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support core removal and packaging operations, but these exposure results were not available during the inspection. The NRC will review the exposure records for June 2011 and beyond during a future inspection.
The inspector conducted a review of the licensees compliance with TS requirements.
The licensee had one air particulate monitor and three area radiation monitors in service to comply with TS 3.2 requirements. The ventilation system was operable per TS 3.3.
The licensee had established a program for conducting daily radiation monitor instrumentation checks as required by TS 4.3. The reactor building design specifications were being maintained in accordance with TS 5.2. The reactor committee was implemented as stipulated by TS 6.2. Procedures had been established as required by TS 6.3, and records were being maintained as required by TS 6.6. Finally, annual reports continue to be submitted to the NRC per TS 6.7, and the most recent annual report was submitted to the NRC during September 2010. However, the reactor tank pool water limits, as specified in TS 4.5, were no longer applicable due to fuel removal and water disposal.
The licensee maintained records of semi-annual calibrations of hand-held survey meters. The licensee maintained a sufficient quantity of survey meters for use during routine work activities. The licensee also maintained records of the annual area radiation and air sampling monitor calibrations.
The inspector reviewed the licensees radiological survey records. The licensee routinely conducted monthly surveys of the reactor room. No significant contamination problems were identified during these surveys. The licensee also exchanged and analyzed the continuous air monitor filter on a monthly basis. No detectable contamination was identified in the air samples between January 2010 through May 2011, indicating that decommissioning work activities had not created an airborne hazard. The contractor also conducted supplemental surveys after unusual work activities. These supplemental surveys confirmed that decommissioning activities were not creating loose contamination problems.
The licensee conducted surveys of equipment being free-released from the licensed area. The licensee maintained records of the free-release of various tools, office furniture, pipes, metals, and other loose components. The licensee used a conservative equipment release criteria of 100 dpm/100 cm2 above background for fixed surface contamination. Some of the components failed the release survey, and these components were disposed as radioactive waste.
The licensee conducted annual radiation program reviews as required by 10 CFR 20.1101(c). The inspector reviewed the licensees annual program review for 2010. The annual review was found to be comprehensive. The annual program review included a discussion of the licensees environmental sampling program, a program not specifically required by TS. As part of the annual review, the licensee calculated public exposures to licensed activities. Using conservatism, the licensees assessment concluded that public exposures would be no more than about one-fourth of the annual limit specified in 10 CFR 20.1301(a).
The licensee also maintained records of effluent releases as required, in part, by 10 CFR 20.1101(d). The results for 2010 were available during the inspection. For the first half of 2010, the licensee estimated a release of 0.587 millicuries of argon-41, a noble gas,
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during reactor operation. (Non-radioactive argon-40, a natural element in the air, will diffuse into the pool through the pool surface. The diffused argon-40 can absorb a neutron during reactor operations, a reaction which converts the argon-40 into argon-41.
Argon-41, a radioactive isotope, can then escape to the atmosphere through the pool surface. The licensee previously calculated the argon-41 production rate and documented its calculation in the Final Safety Analysis Report.) Using the COMPLY computer code, this release of argon-41 was calculated to have resulted in less than 1 millirem of public dose, well below the annual limit specified in 10 CFR 20.1301(a).
Because the reactor was permanently shut down during May 2010, there were no gaseous effluent releases for the second half of 2010.
Both the licensee and the contractor provided decommissioning worker training.
Radioactive material worker training was conducted during May 2011, prior to start of decommissioning work. The contractor also conducted daily planning and safety meetings to discuss the work activities scheduled for that day.
The licensee is required to maintain an emergency plan in accordance with 10 CFR 50.54(q). Analyzed accidents include fire, spilled water, airborne contamination releases, and transportation accidents. The licensee minimized the potential for accidents by limiting the use of flammable materials in the work areas, disposing of the tank water, using dedicated ventilation systems, and using containment systems during work activities that have the potential to create an airborne hazard.
Annual emergency response drills were held during September 2010 and May 2011.
The drills consisted of table-top exercises to discuss licensee responses to potential accidents. The potential accidents included a decommissioning worker falling into the reactor pool, dropping of a fuel transfer cask into the pool, and injury of a worker. The licensee also conducted an annual audit of the emergency plan and emergency procedures during September 2010. The annual audit confirmed that emergency information postings were up to date, agreement letters were in place for medical and emergency response organizations, the emergency kit was complete, and the security alarm was functional. Finally, the licensee submitted a revised emergency plan to the NRC by letter dated May 31, 2011, to remove all reactor operations portions of the plan, to bring the plan into agreement with the possession only status of the license.
1.3 Conclusions
The licensee and its contracted work force were conducting decommissioning activities in accordance with the NRC-approved decommissioning plan.
The licensee established sufficient procedure guidance to control site decommissioning activities. Site staffing was in compliance with technical specification requirements. The licensees final status survey plan was in general agreement with NRC guidance.
The NRC inspector conducted a survey in two rooms located above the former reactor to determine if these two areas were free of licensed radioactive material. The measured radioactivity levels were below the criteria for unrestricted release specified in the NRC-approved decommissioning plan. The licensee plans to conduct its final status survey of these two rooms in the near future.
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The licensee established radiation protection, effluent monitoring, and emergency response programs in accordance with license and regulatory requirements.
Exit Meeting Summary
The NRC inspector presented the inspection results to the licensees representatives at the conclusion of the onsite inspection on June 24, 2011. During the inspection, the licensee did not identify any information reviewed by the NRC inspector as proprietary information.
ATTACHMENT
SUPPLEMENTAL INSPECTION INFORMATION
PARTIAL LIST OF PERSONS CONTACTED
Licensee
R. Banks, University Project Manager C. Dewitt, Project Manager, Decommissioning Contractor A. Farber, Reactor Supervisor R. Offerle, Director, Nuclear Reactor Lab D. Silvain, Director, Radiation Control Office R. Wagner, Supervisor, Radiation Control Office
INSPECTION PROCEDURE USED
IP 69013 Research and Test Reactor Decommissioning
ITEMS OPENED, CLOSED, AND DISCUSSED
Open
None
Closed
None
Discussed
None
LIST OF ACRONYMS USED
CFR
Code of Federal Regulations cpm
counts per minute dpm/100 cm2
disintegrations per minute per 100-square centimeters IP
NRC Inspection Procedure LLD
lower limit of detection TS
technical specifications