Module 8: Uncontrolled Release of Radioactive Material

RPT 243 Instructional Resources

Module 8: Uncontrolled Release of Radioactive Material

Table of Contents:

Resources Key 2

Module Readings and Homework 2

Primary Scenario “Unmonitored Release During Tag-out Activity” 2

Transfer Scenario “Radioactive Source Discovered Outside the Radiologically Controlled Area” 2

Transfer Scenario Original Event Descriptions 3

Transfer Scenario “Radioactive Source Discovered Outside the Radiologically Controlled Area” 3

ACAD References 4

Resources Key

This refers to: / This reference:
ACAD / National Academy for Nuclear Training, Uniform Curriculum Guide for Nuclear Power Plant Technician, Maintenance, and Nonlicensed Operations Personnel Associate Degree Programs, ACAD 08-006.
DOE-SG / Office of Environmental, Safety and Health: Radiological Control Technician Training Site Academic Training Study Guide Phase I, Project Number TRNG-0003
Available at: http://nsedu.rnet.missouri.edu/docshare/. File is located under the Docs/General Curriculum/DOE materials folder.
G. / Gollnick, D. (2006). Basic Radiation Protection Technology, 5th Ed. Pacific Radiation Corporation, Altadena, CA.

Module Readings and Homework

Primary Scenario “Unmonitored Release During Tag-out Activity”

Core Concept: Techniques and precautions for mitigating the consequences of uncontrolled radioactive material release
Homework
Readings / Calculation Items / Non-calculation Items
G., Chap. 10, 420-427 / N\A / G., Chap. 10, # 12
Core Concept: Methods for estimating activity released during an incident
Homework
Readings / Calculation Items / Non-calculation Items
N\A / N\A / N\A

Transfer Scenario “Radioactive Source Discovered Outside the Radiologically Controlled Area”

· Refer to readings and homework for primary scenario above.

· The complete text of the event for this scenario is in the section “Transfer Scenario Original Event Descriptions” below.

Transfer Scenario Original Event Descriptions

Use the complete text of these events to assess students’ ability to analyze the event, and apply appropriate safety and response procedures.

Transfer Scenario “Radioactive Source Discovered Outside the Radiologically Controlled Area”

Description: Two liquid process radiation monitor skids were removed from storage and transferred to a scrap vendor as surplus. The vendor noticed small radioactive material labels in inconspicuous locations on both skids and informed the originating station’s purchasing personnel. The radiation protection manager (RPM) was informed of the issue the following morning and dispatched health physics personnel to the vendor's facility. The process skids were subsequently determined to each contain an exempt 8 microcurie Cs-137 check source. Surveys revealed no loose surface contamination and expected radiation levels of <0.2 mrem/hr on contact with the source housings. The sources and their housings were removed from the process skids, transported to the site in accordance with DOT requirements, and placed in the radioactive materials storage cage in the main warehouse.
Since the skids were located in an area where no special storage controls were imposed, only an incidental observation of the radioactive material labels and/or review of the attached tags would have prevented transfer of the sources to the vendor. In this case, the material handler did not note the radioactive material labels due to their placement on the side of the source housing, nor were the attached handwritten tags observed. Material handlers were not expected to perform detailed inspections of the material on the surplus list, only to verify that the correct item was transferred to the vendor.
Causes: The root cause of this event is the process for control of exempt sources stored in the warehouse did not establish adequate barriers to ensure such sources received proper disposal.
Corrective Actions:
1. Research and walk-downs were performed in order to identify other cases where materials containing radioactive check sources were stored outside of radiological storage areas. No cases were noted.
2. Research verified that no other sources had been inadvertently transferred to second parties.
3. Sales of scrap/surplus materials were temporarily halted pending implementation of appropriate corrective measures.
4. Controls were implemented to require placing all incoming radioactive material in the radioactive material storage cage or within a temporary radioactive material storage area in the warehouse if the item is too large.
5. Procedures were revised to require material handlers to inspect materials prior to movement for labels and tags that indicate special handling is required.
6. Appropriate personnel were trained on the lessons learned from this event.

ACAD References

Note: ACADs listed in the RPT 243 instructors’ guide introduction document may also apply.

ACAD
3.3.12 RADIOLOGICAL INCIDENT EVALUATION AND CONTROL
· Estimate activity released during an incident using the following:
– Airborne activity levels in a plume
– Contamination levels and extent of area contaminated
– Gaseous/particulate specific activity and volume released
– Liquid specific activity and volume released
– Pre-release and post-release radiation surveys (for example, pipe, valves, tanks)
3.3.14 RADIOACTIVE MATERIAL CONTROL
· Describe the controls over radioactive effluent releases, including the following:
– Normal liquid and gaseous radioactivity release paths
– Radiation monitors used to detect and measure releases
– Procedural controls and records associated with releases
– Off-site dose calculations for releases
– Use of derived air concentration and technical specification limits
– Notifications and actions required for abnormal releases
– Radiological environmental technical specifications

Module 8 Uncontrolled Release of Radioactive Material

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A Product of DOL Grant # HG-15355-06-60

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