Information Notice No. 93-69: Radiography Events at Operating Power Reactors
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION &
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555
September 2, 1993
NRC INFORMATION NOTICE 93-69: RADIOGRAPHY EVENTS AT OPERATING POWER REACTORS
All holders of operating licenses or construction permits for nuclear power
reactors and all radiography licensees.
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert licensees to three events involving radiography at operating
nuclear power plants. It is expected that recipients will review the
information for applicability to their facilities and consider actions, as
appropriate, to avoid similar problems. However, suggestions contained in
this information notice are not NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
During three events in late 1992 and early 1993, employees at nuclear reactor
facilities circumvented controls established to ensure the safe conduct of
radiography. In each event, licensee personnel made unauthorized entries into
areas where radiography was either just about to occur or in progress. No
significant exposures resulted from these events; however, such events
indicate a potential for significant exposures.
On December 9, 1992, an operator on routine rounds in the auxiliary building
entered an area that was temporarily roped off and posted with a sign that
read, "High Radiation Area; Radiography In Progress; Exclusion Area; Do Not
Enter." The operator had read and signed a radiation work permit that allowed
entry into high radiation areas normally encountered during operator rounds
and felt that he was authorized to enter the area. However, Zion Station
procedures require the use of a specific radiation work permit to enter areas
in which radiography is taking place. Once inside the area, the operator
encountered the radiographer who had just finished setting up his equipment
and was doing a final boundary check. The radiographer noted he was not
authorized to enter this area and escorted the operator from the radiography
area. Subsequent interviews with the operator indicated that he was unaware
of the significant radiological hazards associated with radiography.
September 2, 1993
Page 2 of 3
On March 27, 1993, a licensee supervisor made an unauthorized entry into an
area in the turbine building that was temporarily roped off and posted with a
sign that read "Radiation Area; Danger - Keep Out; Radiography In Progress;
Contact Health Physicist Prior To Entry." The supervisor was obtaining
temperature data in the area and had not read or signed the appropriate
radiation work permit nor was he wearing proper dosimetry for the restricted
area. After obtaining his data, he was observed leaving the area by Health
Physics personnel who were responsible for watching the boundary while
radiography was in progress. The Health Physics personnel were watching a
different boundary when the licensee supervisor entered the unauthorized
radiography area. Subsequent interviews with the individual indicated that he
did not stop and read the sign. The licensee dose estimate indicated that the
individual received an approximate dose of 0.001 mSv [0.1 mrem].
About 11:00 p.m. on February 13, 1993, two workers made an unauthorized entry
into a posted radiologically controlled area established for radiography in
the Unit 1 high-pressure coolant injection building. The two radiographers
and the radiation protection technician involved with the radiography were on
a meal break at the time of the entry. After the break, the radiographers and
the radiation protection technician returned to the radiological controlled
area, without verifying the area was free of personnel. Radiography was
resumed and after 5 minutes of a 6 minute exposure had elapsed, the
radiographers observed the two workers leaving the area. In its review of the
event, the licensee determined that the two workers disregarded the postings
and intentionally entered the area to hold a personal conversation in a room
on the second floor of the building. Both workers were wearing
thermoluminescent dosimeters but had not signed the appropriate radiation work
permit for the radiography area. The route to the second floor led through
the first-floor room where the radiography source was located, but was some
distance away from the source. The licensee determined that doses of 0.15 mSv
[15 mrem] and 0.30 mSv [30 mrem] were received by the two individuals. The
two individuals received disciplinary action from the licensee.
Radiography sources can create radiation fields in which permissible
occupational dose standards can be exceeded in a short period of time.
Although doses were low in the three events described above, each could have
resulted in more serious exposures had the timing been different or had
personnel been closer to the radiography source. Appropriate enforcement
actions have been taken against the licensees as a result of the events. In .
September 2, 1993
Page 3 of 3
an effort to improve control during radiography, licensees have taken the
corrective actions, including some of the following, as a result of their
review of and lessons learned from the events.
(1) Heightened employee awareness of the potential hazards associated with
radiography through the use of station newsletters.
(2) Enhanced general employee training to ensure that licensee employees
receive information describing the radiological hazards associated with
radiography and radiography controls.
(3) Emphasized to licensee employees the importance with regard to safety of
obeying radiological procedures, signs, and warnings.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate Office of Nuclear
Reactor Regulation project manager.
/s/'d by CJPaperiello /s/'d by BKGrimes
Carl J. Paperiello, Director Brian K. Grimes, Director
Division of Industrial Division of Operating Reactor Support
and Medical Nuclear Safety Office of Nuclear Reactor Regulation
Office of Nuclear Material Safety
Technical contacts: William G. Snell, RIII
John B. Carrico, NMSS
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Page Last Reviewed/Updated Wednesday, March 24, 2021