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Home My WebLink About851162.tiff SSINS No. : 6835 IN 85-43 ,I ne ry ^ UNITED STATES • Cirri" "° „- NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT ,, `"'— "�� / .3i c; WASHINGTON, D. C. 20555 11'? JUG 11� ! 31985 May 30, 1985 GREELEY, cOLO. IE INFORMATION NOTICE NO. 85-43: RADIOGRAPHY EVENTS AT POWER REACTORS Addressees: All nuclear power reactor facilities holding an operating license (OL) or a construction permit (CP). Purpose: This information notice is provided to alert licensees to three events that occurred at nuclear power plants in the preoperational phase. No significant personnel exposures resulted from these events; however, such events indicate a potential for significant exposures. Licensee corrective actions and lessons learned from the events are discussed. It is expected that recipients will review this information for applicability to their facilities and consider actions, if appropriate, to preclude similar problems at their facilities. However, suggestions contained in this notice do not constitute NRC requirements; therefore, no specific action or written response is required. Description of Circumstances: A brief description of each of the three events is provided in Attachment 1. In each event, the responsible radiographers failed to maintain a high radia- tion area (created by radiographing) clear of unauthorized personnel . In each case, the radiographer did not use all reasonable means to ensure the affected "shot" area was evacuated. In two of the events, bullhorns (voice amplifiers) were either unavailable, in disrepair, or simply not effectively used, even though required by local procedures. In highly congested areas , such as BWR drywells, visual-only searches for clearing/warning personnel simply are not effective. In one case, the radiographer left his watch area during the exposure. In all the events, the radiographers promptly retrieved and stored the sources when they discovered unauthorized personnel in the affected area. Discussion: 10 CFR 34 establishes licensing and radiation safety requirements for radiogra- phers. Part 34 specifically requires certain precautionary procedures, making the radiographer responsible for ensuring worker safety by maintaining proper access controls for areas affected by radiographic operations. However, each power plant licensee can help increase worker awareness of radiography opera- tions. Power plant licensees can help increase overall worker safety by cooperating with and augmenting the radiographer' s control actions, where appropriate. 851162 8505280187 i IN 85-43 May 30, 1985 Page 2 of 2 Appropriate enforcement actions against the radiographers as a result of the events either have been taken or are under consideration. In an effort to improve control and increase their oversight during radiograph- ing, power plant licensees have taken the following corrective actions as a result of their review and lessons learned from the three events. 1. Plant control procedures for radiographing have been strengthened by clearly defining specific plant actions to provide additional oversight measures to augment the radiographers control efforts. 2. Plant worker awareness of on-going radiography was increased by training opportunities offered by routine plant safety meetings. The importance of remaining vigilant and obeying all radiological warning postings was reemphasized. 3. Appropriate plant health physics coverage is provided for radiographic operations. No specific action or written response is required by this information notice. If you have any questions about this matter, please contact the Regional Administrator of the appropriate regional office or this office. dwar . Jordan, Director Divi n of Emergency Preparedness an Engineering Response Office of Inspection and Enforcement Technical Contacts: J. E. Wigginton, IE (301) 492-4697 R. L. Pedersen, IE (301) 492-9425 Attachments: 1. Event Summaries 2. List of Recently Issued IE Information Notices Attachment 1 IN 85-43 • May 30, 1985 Event Summaries Perry Nuclear Power Plant, Unit 1 Event Date: 6/16/84 While radiographing in the drywell using a 200 curie Ir-192 source, radiogra- phers noticed two workers leaving the controlled shot high radiation area. These workers had been working near the reactor vessel , about 15 feet from the source (on a lower elevation) while a full radiographic exposure (13 min. ) and an abbreviated (2 min. ) exposure had occurred. According to the radiographers, a visual search was made, radiation warning signs and barriers erected, but no bullhorn was used to warn personnel . The bullhorn normally used had been inoperable for several weeks. The NRC inspector noted that the workers' location was shielded from view in most directions by piping, components, and scaffolding. Based on a reenactment of the incident (exposing dosimeters in the location that had been occupied by the workers), a maximum dose reading of 15 mrem was observed. Clinton Power Station, Unit 1 Event Date: 1/5/85 While radiographing the biological shield on the 737-foot elevation in the drywell , a radiographer noticed two workers descending a ladder approximately 20 feet from the exposed 76-curie Ir-192 sealed source. Although bullhorn and public address system warnings were given (but none on the elevation where the workers had been located) , workers on the 755-foot elevation reportedly could not hear warnings. Based on a reenactment of the incident, workers were each assigned 20 mrem from their stay in the high radiation area (maximum exposure rate of 600mR/hr). Hope Creek Nuclear Generating Station, Unit 1 Event Date: 3/21/85 While radiographing a piping weld inside the control building, a radiographer noticed a worker inside the no-access area. Contrary to the surveillance requirements for a high radiation area, the radiographer had left his watch area when the 53 curie Ir-192 source was exposed; upon returning, he noticed the apparent inadvertant entry. Further search found a second worker in the affected area. Based on the licensee' s worst-case evaluation, it is unlikely that any worker received a dose greater than 12 mrem. Attachment 2 IN 85-43 May 30, 1985 LIST OF RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No. Subject Issue Issued to 85-42 Loose Phosphor In Panasonic 5/29/85 All power reactor 800 Series Badge Thermo- facilities holding luminescent Dosimeter (TLD) an OL or CP Elements 85-41 Scheduling Of Pre-Licensing 5/24/85 All power reactor Emergency Preparedness facilities holding Exercises a CP 85-40 Deficiencies In Equipment 5/22/85 All power reactor Qualification Testing And facilities holding Certification Process an OL or CP 85-39 Auditability of Electrical 5/22/85 All power reactor Equipment Qualification facilities holding Records At Licensees' an OL or CP Facilities 85-38 Loose Parts Obstruct Control 5/21/85 All PWR facilities Rod Drive Mechanism designed by B&W holding an OL or CP 85-37 Chemical Cleaning Of Steam 5/14/85 All pressure water Generator At Milestone 2 reactor facilities holding an OL or CP 84-55 Seal Table Leaks At PWRs 5/14/85 All power reactor Sup. 1 facilities holding an OL or CP 85-20 Motor-Operated Valve Failures 5/14/85 All power reactor Sup. 1 Due To Hammering Effect facilities holding an OL or CP 85-36 Malfunction Of A Dry-Storage, 5/9/85 All licensees Panoramic, Gamma Exposure possessing gamma Irradiator irradiators OL = Operating License CP = Construction Permit SSINS No. : 6835 IN 85-42 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C. 20555 May 29, 1985 IE INFORMATION NOTICE NO. 85-42: LOOSE PHOSPHOR IN PANASONIC 800 SERIES BADGE THERMOLUMINESCENT DOSIMETER (TLD) ELEMENTS Addressees: All holders of a nuclear power plant operating license (OL) or a construction permit (CP). Purpose: This information notice is provided to alert NRC licensees to a problem noted in some Panasonic 800 series TLD badges that has caused spurious high readings in one of the badges' TLD elements. This information is intended to assist licensees in diagnosing any spurious readings with the Panasonic TLD system. It is expected that recipients will review the information provided for appli- cability, if appropriate, to their dosimetry programs. However, suggestions contained in this information notice do not constitute NRC requirements; therefore, no specific action or written response is required. Description of Circumstances: The Panasonic 800 series TLD badge contains a card that holds four TLD ele- ments. Each TLD element consists of a thin film of TL phosphor attached to a disk backing with a clear teflon bubble cover. During reading, the phosphor is heated by converging infrared light on the backing. The luminescence from the phosphor (which is proportional to the dose received) radiates through the teflon cover and is read with a photomultiplier tube. Several Panasonic TLD users (including NRC' s Region I) have identified badges where crystals of the phosphor have detached themselves from the backing of the element, resulting in high erratic readings in that element. When viewed through a stereoscopic microscope, phosphor crystals can be observed sticking to the teflon cover (presumably by electrostatic charge). In this position, the loose TL material is not in contact with the backing and does not get heated when the badge is read. These TL crystals remain at an elevated energy state and continue to accumulate dose. Apparently erratically high readings result when the loose crystals are shaken back onto the backing surface during a subsequent reading. They are then heated and luminescence proportional to the total doses received during several read cycles is produced. This process can cause the affected element to erroneously read as much as an order of magnitude higher than the other elements in the same card. Although the 8505280181 IN 85-42 May 29, 1985 Page 2 of 2 frequency of occurrence is small (one licensee found only one problem badge in 30,000), there is evidence that the frequency increases substantially once the badges have been through 100-200- read cycles. Panasonic has a manufacturing quality control (QC) specification on the amount of loose phosphor in an element. However, physical shock and thermal cycles, experienced during badge use, appear to loosen additional material . Panasonic has stated that they have modified their QC program to provide a greater physical challenge to the badge before they are screened. For those badges already in use, licensees can visually inspect any TLD elements suspected of having loose TL crystals. Panasonic has been exchanging badges identified as having excessive loose TL material . No specific action or written response is required by this information notice. If you have any questions about this matter, please contact the Regional Administrator of the appropriate regional office or this office. %4a11/ r L. Jord" an, Director Divi 'on of Emergency Preparedness an Engineering Response Office of Inspection and Enforcement Technical Contacts: R. L. Pedersen, IE (301) 492-2967 J. E. Wigginton, IE (301) 492-9425 Attachment: List of Recently Issued IE Information Notices Attachment 1 IN 85-42 May 29, 1985 LIST OF RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No. Subject Issue Issued to 85-41 Scheduling Of Pre-Licensing 5/24/85 All power reactor Emergency Preparedness facilities holding Exercises a CP 85-40 Deficiencies In Equipment 5/22/85 All power reactor Qualification Testing And facilities holding Certification Process an OL or CP 85-39 Auditability of Electrical 5/22/85 All power reactor Equipment Qualification facilities holding Records At Licensees' an OL or CP Facilities 85-38 Loose Parts Obstruct Control 5/21/85 All PWR facilities Rod Drive Mechanism designed by B&W holding an OL or CP 85-37 Chemical Cleaning Of Steam 5/14/85 All pressure water Generator At Milestone 2 reactor facilities holding an OL or CP 84-55 Seal Table Leaks At PWRs 5/14/85 All power reactor Sup. 1 facilities holding an OL or CP 85-20 Motor-Operated Valve Failures 5/14/85 All power reactor Sup. 1 Due To Hammering Effect facilities holding an OL or CP 85-36 Malfunction Of A Dry-Storage, 5/9/85 All licensees Panoramic, Gamma Exposure possessing gamma Irradiator irradiators 84-52 Inadequate Material 5/8/85 All power reactor Sup. 1 Procurement Controls On facilities holding The Part Of Licensees And an OL or CP Vendors 0L = Operating License CP = Construction Permit Hello