ML16148A709
| ML16148A709 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/17/1992 |
| From: | Bryan Parker, Pharr E, Rankin W, Shortridge R, Testa E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16148A705 | List: |
| References | |
| 50-269-92-17, 50-270-92-17, 50-287-92-17, NUDOCS 9212040272 | |
| Download: ML16148A709 (23) | |
See also: IR 05000269/1992017
Text
REG
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION I
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
NOV 2 0 1992
Report Nos; 50-269/92-17, 50-270/92-17
and 50-287/92-17
Licensee: Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.: 50-269, 50-270, 50-287
License Nos.: DPR-38, DPR-47, DPR-55
Facility Name: Oconee 1, 2, and 3
Inspection Conducted: August 3-7, 1992*
September 2-4, 1992+
September 8-9, 1992+
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adiation Protection Branch
Radiological Protection and Emergency Preparedness Branch
Division of Radiation Safety and Safeguards
SUMMARY
Scope:
This routine, unannounced inspection was conducted in the area of occupational
exposure during extended outages and included a review of Information Notices.
A second inspection covering two periods was conducted to respond to a
potential exposure in excess of regulatory limits.
This included a review of
the event, how the licensee assessed the event and assigned the exposure, and
a review of the program to determine adequacy in preventing recurrence.
9212040272 921120
PDR ADOCK 05000269
G
Results:
The inspector found the radiation protection (RP) program at Oconee to be
adequate in protecting the health and safety of the public and plant
employees. However, during both inspections, apparent violations of
regulatory requirements were identified that signify the need for improvements
in the RP program and increased attention by plant management.
The (*) signifies reference to the first inspection of August 3-7, 1992.
The
(+) signifies reference to the second inspection ending on September 9, 1992.
(*) Apparent violation for inadequate posting of radiological control zones
with multiple examples:
(a) The normal sump area in containment where people were working in
respirators in very high levels of contamination was not posted as
an airborne radioactivity area; and
(b) There were work areas in the primary chemistry laboratory that
were not posted or taped to signify a controlled contamination
area. These areas had varied readings of 1,000 to greater than
100,000 corrected counts per minute (ccpm).
(*) Apparent violation with examples for failure to label radioactive
material:
(a) Air sampler reading greater than 10,000 ccpm was observed in
Unit 2 Auxiliary Building without.a radioactive material label;
and
(b) A contaminated screwdriver was located in a tool box in the
primary chemistry laboratory unlabeled, and reading greater than
1,200 ccpm.
(+) An apparent violation was identified when a Primary Chemist and a
Radwaste Operator failed to access a Radiation Work Permit (RWP)
prior
to performing radiological work.
REPORT DETAILS
1..
Persons Contacted
Licensee Employees
- B. Baron, Plant Manager
+S. Benesole, Plant Safety Review Group
+S, coy, Supervisor, Radiation Protection
+J. Davis,-Manager, Safety Assurance
+J. Hampton Vice President, Oconee Nuclear Station
+M. Hassell, Scientist, Radiation Protection
+B. Jones, Manager, Chemistry
- +M.
Manager, Regulatory Compliance
+B. Peele, Manager, Engineering
- +S. Perry, Technical Assistant, Regulatory Compliance
- +R. Sweigart, Acting Plant Manager, Operations Superintendent
+M. Thorne, Supervisor, Radiation -Protection
+R. Vassey, Plant Safety Review Group
- L. Wilkie, Manager, Chemistry
- +C. Yongue, manager, Radiation Protection
Other licensee employees contacted during the inspection included
craftsmen, technicians, and administrative personnel.
Nuclear Regulatory Commission
- +B. Desai, Resident Inspector
+P. Harmon, Senior.Resident Inspector
- Attended 1st Exit Interview August 7, 1992
+Attended 2nd Exit Interview September, 9, 1992
2.
Occupational Exposure During Extended Outages (83729)
a.
Organization and Management Controls
The licensee is required by Technical Specification (TS)
6.1.1.1
to establish clear lines of authority, responsibility, and
communication from the highest management levels through
intermediate levels including the operating organization.
The
inspector reviewed staffing levels and lines of authority as they
related to the Radiation Protection (RP)
program and discussed the
organization with the RP Manager. The inspector verifiedthat the
licensee had not made changes that would adversely affect their
ability to implement -critical elements of the RP program.
42
b.
Audits and Appraisals (83729)
TS 6.1.3.4 requires that audits of plant activities be performed
under the cognizance of the Nuclear Safety'Review Board (NSRB) and
that the audits.shall encompass, in part, the conformance of plant
operation to provisions contained within the TSs and applicable
license conditions at least once per 12 months.
The inspector reviewed a Quality Assurance (QA) audit of RP
program activities, NG-92-03 (ON), performed since the previous
NRC inspection of program activities conducted January 27-31,
1992, and documented in Inspection Report (IR)
92-06. The
inspector noted that the audit was well-planned and documented
and, most importantly, appeared to adequately assess the program.
The audit contained items of substance relating.to the program and
valid nonconformances were identified. The inspector noted
thorough investigations and responsive commitments by-management
to implement corrective actions for the deficiencies identified.
The inspector also noted a high level of management visibility for
audit findings and subsequent responses.
The inspector also reviewed Radiological Deficiency Reports (RDRs)
and Problem Identification Reports (PIRs) initiated from
January 1 to July 31, 1992.
During discussions with licensee
representatives, the inspector was informed that whereas the RDR
was only an internal RP self-assessment program, the PIR program
was to be used by all work groups to identify and investigate any
plant-related problems.
The inspector noted that the 19 RDRs which were written during the
1st quarter of 1992 usually documented poor work practices
resulting in contamination, both personnel and area. As well, 17
incident reports involving improper use of dosimetry and drifting
or offscale self reading dosimeters (SRDs) were made during the
first quarter of 1992. Since the PIR program was initiated in
April 1992, 15 RP-related PIRs had been written. The inspector
noted that these reports included procedural violations, non-ALARA
components/areas which posed potential procedural violations, and
lost, drifting, and offscale dosimetry. During review of the
identified RORs and PIRs, the inspector noted that the
investigations were thorough and that corrective actions were
appropriate and comprehensive. The inspector noted that
corrective actions did not always appear to be timely in that nine
of the 15 PIRs, had not been resolved at the time of the
inspection. However, the inspector noted that the licensee did
track PIRs as to their open or closed status and that identified
problems were trended quarterly. The inspector informed licensee
representatives that the method for trending deficiencies and for
tracking open items to final and approved resolution appeared
effective.
No violations or deviations were identified.
3
3.
Training and Qualifications (83729)
10 CFR 19.12 requires, in part, that the licensee instruct all
individuals working in or frequenting any portions of a restricted area
in the health protection aspects associated with exposure to radioactive
material or radiation; in precautions or procedures to minimize
exposure; in the purpose and function of protection devices employed; in
the applicable provisions of the Commission regulations; in the
individual's responsibilities; and in the availability of radiation
exposure data.
The inspector reviewed training provided to contract technicians in
preparation for the Unit 3 refueling outage. During discussions with
licensee personnel, the inspector was informed that prior to performing
RP tasks, vendor technicians must first successfully complete General
Employee Training (GET)
and respiratory protection training; a written
Health Physics (HP) knowledge test; site specific training, to include
applicable industry events; and qualification in tasks which the vendor
will be assigned. The inspector noted that successful completion of the
required training sessions required passing each associated written test
with at least 70 percent correct for seniors. The inspector reviewed
the HP knowledge test and noted that the test adequately addressed basic
HP concepts. However, the inspector considered passing standards of
70 percent for senior technicians and 50 percent for junior technicians,
respectively, to be relatively low for the material content.
The
inspector was informed that in response to a concern regarding vendor
passing standards raised during IR 92-06, the licensee was evaluating
increasing the passing score for senior technicians to 80 percent.
Additionally, licensee representatives stated that each vendor's
qualifications were assessed by the RPM and evaluations of the
technician's performance to certain tasks were performed as necessary.
The inspector also discussed with licensee representatives training
provided to the core vendor technician staff. The inspector was
informed that this core group consisted of 45 technicians which provided
RP support to the three Duke Power nuclear stations during outages.
However, during non-outage operations, a group of 15 technicians were
assigned to a base plant. .The 15 technicians assigned'to Oconee Nuclear
Station during operating periods participated in both continuing
training and special training sessions.
The inspector was informed that
special training was recently implemented for RP technicians And the 15
core vendors. This special training consisted of 34 computer-based
training modules and associated tests which focused primarily on
refresher HP theory and practices.
The modules were introduced in 1991
and by December 31, 1992, all technicians, both in-house and vendors,
were required to successfully complete 12 of the 34 training modules.
The inspector reviewed training files for selected RP te .hnicians signed
in on RWP associated with removal and decontamination of component drain
header piping. For those records reviewed, training was current and
included GET, site-specific training, the HP knowledge test, and various
task qualifications. Based on the above, the inspector found the
licensee's vendor RP training program to be satisfactory.
No violations or deviations were identified.
4.
External Exposure Controls (83729)
10 CFR 20.101 requires that no licensee possess, use, or transfer
licensed material in such a manner as to cause any individual in a
restricted area to receive in any period of one calendar quarter a total
occupational dose in excess of 1.25 rems to the whole body, head and
trunk, active blood forming organs, lens of the eyes, or gonads;
18.75 rems to the hands, forearms, feet and ankles; and 7.5 rems to the
skin of the whole body.
The inspector reviewed 1992 external exposure records for workers
involved with RWP activities associated with the Unit 3 component drain
header and valve replacement. The inspector noted that the maximum
whole body dose during any one quarter was 450 millirem (mrem).
However, during discussions with licensee representatives, the inspector
was informed of an exposure in excess of administrative limits which
occurred in January 1992. The inspector reviewed the accompanying RDR
which reported the circumstances of the incident and determined that,
based on TLD results, the individual received an exposure of 564 mrem,
exceeding his administrative limit of 500 mrem.
Investigation of the incident revealed that the individual received the
exposure while installing level indicating equipment on both the hot and
cold legs of "B" steam generator. On January,12 and 13, 1992, the
individual made three separate entries into the reactor building to
perform the specified work and received exposures of 250 mrem, 60 mrem,
and 195 mrem, respectively, based on electronic dosimeter readings.
When the individual attempted to enter the Radiation Controlled Area
(RCA) the following day, the Electronic Dose Capture (EDC) system would
not allow entry since the individual had exceeded his 500 mrem
administrative limit. Further investigations revealed that a different
RP technician provided job coverage for the individual on January 13,
1992. This RP technician did not attend the pre-job ALARA briefing on
January 12, 1992, and was not aware of complete dose rates in the work
area, nor the workers' complete dose information. As well, longer than
estimated stay times were encountered and no dose extensions were
requested by the workers' supervisor. Additionally, the licensee
determined that the individual did not understand basic radiological
terms and the ALARA impact of body positioning and low dose waiting
areas during high radiation work, nor did the individual fully
understand the EDC system. Corrective actions in response to the
incident included GET retraining for the involved individual, and
counseling for the RP technician on the importance of complete job scope
5
review, detailed pre-job surveys, and knowledge of workers' remaining
exposure -imits. As well, a case study of the incident was prepared for
presentation to RP technicians and supervisors to ensure continued
awareness to prevent recurrence.
The inspector reviewed the individual's exposure history for first and
second quarter 1992 and determined that the maximum dose received during
either quarter was 564 mrem. The inspector concluded that for those
selected individuals reviewed, all external exposures were within 10 CFR
Part 20 limits.
During tours of the Unit 3 Containment Building, the inspector noted
that the incore instrument wires retracted into the incore instrument
tank, and the tank was flooded with water for shielding.
However, the
method of restraint appeared to be a continuous restraint wire running
through all the lifting bail/support clamp type arrangement.
It
appeared to the inspector that the restraint wire running though the
lifting bail/support clamp could be inadvertently lifted which would
lift some of the incore wires from their storage location.
The
inspector discussed this at the exit interview with licensee personnel
and the licensee agreed to review further to see if the incore wires
were properly restrained to prevent inadvertent movement.
10-CFR 20.203(c)(1) requires that each high radiation area shall be
conspicuously posted with a sign or signs bearing the radiation symbol
and the words "Caution High. Radiation Area."
TS 6.4.1, in part, requires that the station be operated and maintained
in accordance with approved procedures.
Paragraph 6.4.1.g specifies
personnel radiation protection procedures.
Health Physics Manual
Section 4.2, Posting of Radiologically Controlled Areas and Materials,
dated March 13,
1986, in Step 3.1.8, defines a high radiation area as
any area-which is readily accessible to personnel and there exists a
potential to expose a major portion of the whole body to greater than
100 millirem per hour (mrem/hr).
During tours of the Unit 3 containment building, the inspector noted in
several areas that there were no barricades to prevent entry or warn
personnel of high radiation levels in the specific area.
There was a
rope and a sign posting the area to the "B" lower steam generator (S/G)
entrance; however, it was not placed across the entryway after the last
person exited the area. The manway was removed from the "B" lower S/G
manway for eddy current testing and a yellow flashing light was in the
area. However, there was no barricade or sign at the entry point of the
area, and thus no barrier existed that led to the 8.9 rem/hour radiation
field at 18 inches from the S/G tube sheet.
The inspector immediately
reported the condition to a health physics technician (HPT)
who posted
the area as required.
The same problem was observed at the entry point (ladder) leading to the
reactor cavity. The area had a flashing warning light; however, the
rope barrier and sign leading to the reactor cavity entrance, with dose
6
rates greater than 500 mrem/hr, were not in place. The HPT in the area
took immediate actions to post the area as required by procedure.
5.
Internal Exposure Controls (83729)
a.
Internal Exposure Assessments
10 CFR 20.103(a)(1) states that no: licensee shall possess, use, or
transfer licensed material in such a manner as to permit any
individual in a restricted area to inhale a quantity of
radioactive material in any period of one calendar quarter greater
than the quantity which would result from inhalation for
40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> per week for 13 weeks at uniform concentrations of
radioactive material in air specified in Appendix B, Table 1,
Column 1.
10 CFR 20.103(a)(3) requires, in part, that the licensee, as
appropriate, use measurements of radioactivity in the body,
measurements of radioactivity excreted from the body, or any
combination of such measurements as may be necessary for timely
detection and assessment of individual intakes of radioactivity by
exposed individuals.
The inspector reviewed internal exposure records for selected
individuals associated with RWP work on the Unit 3 component drain
header and valve replacement. For those records reviewed, the
inspector noted a maximum quarterly exposure of 6.32 Maximum
Permissible Concentration-hours (MPC-hrs) for third quarter 1992,
to date. During discussions with licensee representatives, the
inspector was informed that following reactor shutdown for the
Unit 3 outage and prior to operation of the containment purge
system, the licensee experienced airborne iodine levels in the
reactor building up to approximately 16 percent MPC. Licensee
representatives also stated that body burden analyses (BBAs) were
performed for an approximate 100 percent representative sampling
of workers in the reactor building during the increased airborne
levels. The inspector noted that based on BBAs, no iodine uptakes
were detected. The inspector also noted that for the individual
assigned 6.32 MPC-hrs during the first week of the Unit 3 outage,
full-face air-purifying respiratory protection was worn as
necessary and that the individual's internal exposure was based on
air sample results in the work area. The inspector verified that
no exposures in excess of the 40 MPC-hr control measure had
occurred since January 1, 1992.
No violations or deviations were identified.
7
b.
Respiratory Protection Program
10 CFR 20, Appendix A, footnote(d), requires adequate responsible
air of the quality and quantity in accordance with NIOSH/MSHA
certification described in 30 CFR Part 11 to be provided for the
atmosphere-supplying respirators.
30 CFR 11.121 requires that compressed, gaseous breathing air
meets the applicable minimum grade requirements for Type 1 gaseous
air set forth in the Compressed Gas Association (CGA) Commodity
Specification for Air, G-7.1 (Grade D or higher quality).
The inspector discussed with licensee representatives recent
upgrades in the station's breathing air systems.
Licensee
representatives informed the inspector that during previous years,
existing compressors were not adequate to supply the needed
breathing air capacity,' especially during outages.
Therefore, the
licensee recently upgraded their breathing air systems for each of
the three units, to include the turbine buildings.
Licensee
representatives informed the inspector that each unit's breathing
air would be supplied by two oil-cooled/lubricated compressors,
with approximately 15 manifolds in each reactor building. At the
time of the onsite inspection, the licensee had implemented the
Unit 3 system and was supplying breathing air -during the outage.
Additionally, the inspector was informed that the other units'
systems would be implemented in the near future with further
evaluations and operational design changes ongoing with the Unit 3
system.
HP/0/B/1010/02, Radiological Respiratory Quality Assurance, dated
July 28, 1992, requires any compressor or system used for
breathing air purposes be sampled quarterly to ensure Grade D air
quality.
The inspector reviewed breathing air sampling records
for 1992, to date, and noted that sampling was performed to ensure
Grade D quality air at least quarterly.
The inspector further
noted that with the exception of June 1992, all sample results for
carbon monoxide (CO) were less than 10 parts per million (ppm).
For the June sampling of the seven compressor systems, the
inspector noted that CO results ranged from 10.1 ppm to 13.6 ppm.
During discussions with licensee representatives, the inspector
was informed that the licensee's analysis laboratory had explained
that analyses of the seven samples had to be performed twice.
An
adequate testing quantity was not available-for the second
analyses, which produced erroneous results. During the period
from July 23, to August 3, 1992, the breathing air systems were
resampled and results of less than 10 ppm CO were achieved.
Licensee representatives also stated that CO alarms were located
on each breathing air system and that workers were successfully
removed from utilizing breathing air whenever CO alarms were
noted.
8
The inspector also reviewed and disrussed with licensee
representatives maintenance procedures for breathing air
compressors. The inspector noted that with the exception of one,
the procedures included a step for maintenance personnel to notify
RP after system maintenance in order to determine. if resampling to
verify Grade D compliance was necessary. :For the one procedure
without the step, the licensee initiated actions to change the
procedure and to develop a method for adding the notice
requirement to any future procedures or revisions associated with
breathing air compressor maintenance.
No violations or deviations were identified.
C.
Radioactive Source Control (83729)
During review of 1992 PIRs, the inspector noted an incident
investigation involving two sources which could not be located
during the 1991 annual source inventory. Sources ONSI-109
(nominal 100 microcuries (uCi) of strontium-90) and ONSI-134
(nominal 0.06 uCi of radium-226) were used to perform detector
source checks for two skid-mounted radiation detectors.
These
monitors were recently replaced and the sources were removed so
that the monitors could be disposed. The sources were
encapsulated with epoxy inside a hollow machine screw,
approximately 3/8 inches long. Following removal from the
monitors, the sources were to be maintained and stored by the
Instrumentation and Equipment (I&E) source custodian.
The inspector reviewed the 1991 source inventory and determined
that withthe exception of ONSI-109 and ONSI-134, all sources were
accounted for and leak tested as required. The inspector also
noted that the responsible source custodian had initiated a letter
to the RPM on June 4, 1992, which identified the lost sources by
isotope and activity. Although the custodian could not
conclusively determine the circumstances surrounding the loss,
corrective actions to prevent recurrence were discussed. These
corrective actions included coordination of I&E and RP to
establish a designated, centralized storage area for I&E sources,
storing the sources in lockable cabinets with sign-out logs to
ensure proper control, as well as returning sources to RP for
disposal when no longer needed. RP representatives stated that
the corrective actions should be adequate in preventing other
source losses. During discussions with licensee representatives
the inspector was informed that.the licensee was confident that
although the sources could not specifically be located, they were
maintained within the plant restricted area and probably within
the RCA. This was evidenced by tests with sources of similar
activity and isotopic content to ensure that the lost sources
could not bypass the plant's exit portal monitors. Additionally,
the licensee stated that efforts would continue to locate the
missing sources.
kII
9
Based on the minor safety significance of the issue due to efforts
taken by the licensee to ensure the sources were within the
restricted area and continuing efforts to locate the sources, the
inspector determined the licensee's actions, to date, were
appropriate but informed licensee representatives that their
followup actions would be reviewed during future inspections.
No violations or deviations were identified.
6.
Control of Radioactive Materials and Contamination, Surveys,
and
Monitoring
a.
Cavity Drain and Letdown Pipe Decontamination
10 CFR 20.203(d)(2) requires that each airborne radioactivity area
be conspicuously posted with a sign or signs bearing the radiation
caution symbol and the words "Caution Airborne Radioactivity
Area." TS 6.4.1, in part, requires that the station be operated
and maintained in accordance with approved procedures and
Paragraph g specifies personnel radiation protection procedures.
Health Physics Section Manual 4.2, Step 3.4.1, requires that areas
with airborne concentrations of radioactive materials greater than
25 percent MPC or areas with this potential (normally due to work
being performed in the area) shall be posted as Airborne
Radioactivity Areas.
During a tour of Unit 3 Reactor Building, the inspector noted that
personnel wearing full-face respirators were working in an area
without the posting for airborne radioactivity area in the sign.
The caution sign was posted as a high radiation area with 4000
5000 mr/hr in the alleyway on oilcloth,.50-5000 mr/hr general
area, and up to 450 mrad smearable. The inspector notified the
nearest HPT who posted the area as required. This was reported to
the licensee as an example of failure to post an area as required
by procedure (50-269, 270, 287/92-17-01).
The inspector observed the personnel in the area performing
decontamination of the letdown and cavity drain lines to support
shipment of the-same. The inspector noted that the deconners were
spraying water via a high pressure lance into the piping in the
general location of the normal sump, but the water exiting the
piping was not going into the sump. On occasion, the worker would
decon a piece of pipe with multiple pipes coming off in different
directions. When this pipe was deconned using the high pressure
lance, water would go in the direction of the pipe openings,
sometimes in all directions. The inspector exited containment to
review the RWP that controlled the work. RWP 3389, Revision 0,
dated June 24, 1992, required a pre-job briefing and protective
clothing for working in wet conditions. Radiation surveys of the
piping being deconned ranged as high as 30 R/hr before flushing,
cutting, and removal from the system. Immediately after the
10
Piping was cut out, radiation/contamination surveys ranged as high
as 10,000 mrem/hr gamma and 27,000 mrad beta. The inspector
reviewed the pre-job briefing as documented as Enclosure 5.1 of
HP/O/B/1000/ 73, ALARA Work Packages, dated August 1, 1992. All
personnel on the job were verified as having attended the pre-job
briefing; however, the ALARA considerations during the job stated
that a tent may be required to control the spray but did not
contain any special instructions other than that. The procedure
stated in a note to Step 5, in part, that all sections of the
piping reading greater than 100 mrem/hr should be taken to the
normal sump and deconned with a high pressure sprayer. Surveys of
deconned piping revealed that radiation levels had dropped
significantly, indicating that the extremely high levels of
radiation and contamination prior to decon were caused by loose
crud. The inspector noted that, although the methods to remove
the loose crud from the piping may have been appropriate, the
licensee's failure to adequately contain the crud and/or failure
to employ more restrictive radiological conditions led to poor
radiological work practices. The inspector informed the licensee
that the failure to use a containment as -suggested with ALARA work
packages and the lack of specific instructions on either the RWP
or ALARA Work Package to contain or control the crud was a poor
practice. Upon exiting the RCA, the inspector discussed the
operation and lack of controls with the RP Manager. The RP
Manager stated that this decon method had been used on Unit 1 and
not resulted in any problems.
He also stated that he thought all
piping had been deconned, but if not,,a method to contain the crud
would be utilized.
b.
Hot Particle Contaminations
The inspector noted by review of data and interviews with HPTs
that hot particle contaminations had been a problem during early
parts of the outage and were attributed to known failed fuel. A
total of 122 personnel contamination events (PCEs) occurred from
January 1, 1992, to August 1, 1992. Of these, 29 PCEs involving
hot particles had occurred since the start of the outage on
July 21, 1992, with two being particles on the skin and nine being
particles on clothing. Between August 1 and August 5, 1992,
sixteen PCEs occurred, five of which involved particles on the
skin.
Between August 5, 1992 and September 2, 1992, 88 additional
PCEs occurred. Eighteen of the last 37 were hot particles on the
skin. The inspector expressed concerns to the licensee and the
licensee noted the concerns and attributed the hot particles to
failed fuel.
The licensee stated that all fuel had been inspected
and as part of their new zero fuel defects program, there were no
known leakers in the core. At least eight leaking fuel assemblies
were replaced.
11
The licensee implemented a hot particle surveillance program after
August 6, 1992. The program contained the following guidance:
1.
Once-Through Steam Generator (OTSG) Work
a.
Worker should be surveyed with an open window R02-A
after breaking the plane of the manway with any part
of the body.
b.
Worker should be surveyed with an open window R02-A
after handling highly contaminated equipment inside
playpen (i.e., Probe driver, Roger equipment, hoses,
cables, etc.).
c.
Playpens should be surveyed with an open window R02-A
routinely or after significant work evolutions.
d.
Outside of playpens should be surveyed routinely with
an open window R02-A.
e.
Care should be taken handling plastic bags and plastic
anti-cs because of the static charge which attracts
the.hot particles. Don't forget to survey yourself
routinely.
2.
Breaching Primary Systems/Working with Open Primary Systems
a.
Routinely every hour, survey workers for hot particles
with an R02-A who are physically in contact with open
primary systems and/or laying on floor where systems
have been opened (i.e. CDH, valve work).
b.
Survey open systems, valves, piping, etc., for hot
particles prior to beginning work.
c.
Survey work areas where you know systems have been
opened prior to allowing workers to work there.
The inspector reviewed substantive evidence that the licensee was
taking a number of measures to both detect hot particles and
reduce exposure times. However, the inspector noted that the
problem was more significant than ever with some days having five
or six hot particle skin contaminations.
C.
Control of Radioactive Material
TS. 6.4.1 requires that the station be operated and maintained in
accordance with approved procedures.
0II
12
Oconee Radiation Protcction Manual Procedure (ORPMP) 5.1, Movement
of Radioactive Materials Within the Owner Controlled Area, dated
August 15, 1992, Step 3.1.2.1, requires -in
part that all
radioactive materials removed from the RCZ shall be labeled.
The inspector performed radiological surveys both inside and
outside the RCA. No discrepancies were noted outside the RCA,
however, a high volume portable air sampler outside of the Unit 2
HP office was found to have a reading of 10,000 ccpm and was not
labeled. HPTs were notified and immediately surveyed and properly
labeled the piece of equipment. During a tour of the primary
chemistry laboratory, Room 329 of the Auxiliary Building, the
inspector noted a tool box in the clean area of the laboratory.
The unlabeled tool box contained a screwdriver with levels of
radioactivity greater than 1,200 ccpm. HPTs were called and
confiscated the screwdriver providing proper controls as described
in ORPMP 5.1.
This is a repeat of a non-cited violation
documented by IR 92-06, dated March 6, 1992, when a contaminated
pair of needle nose pliers was found in the same tool box. Since
this was -a
repeat problem, the inspector informed the licensee
that the failure to control and label radioactive materials in
accordance with T.S. 6.4.1 and ORPMP 5.1 was an apparent violation
(50-269/92-17-02, 50-270/92-17-02, and 50-287/92-17-02). A tour
of the primary chemistry laboratory showed that radiological
controls were lax. Contamination was detected in many areas on
counter tops and on equipment that was not labeled or posted as a
contamination zone. For example, greater than 100,000 ccpm were
detected on equipment used to measure the pH of primary samples.
This equipment was not labeled or inside a controlled
contamination zone. Earlier in the year, the NRC found that a
contaminated lead brick that was being used as a laboratory door
stop had contaminated the floor. The inspector also noted that
there were no requirements posted for personnel to frisk after
completing work in a contaminated zone or when leaving the primary
chemistry laboratory. The licensee was informed that this was the
second example of apparent violation for failure to post
(50-269, 270, 287/92-17-01) (see Paragraph 6).
7.
Description of Events Surrounding an Unplanned Exposure (83524)
a.
Description of the Event
On August 14, 1992, the Resident Inspector notified the Region
about a potential overexposure that had occurred in July 1992. On
August 17,
1992, the licensee issued a Problem Investigation
Process Report #3-092-0347, Potential Technical Overexposure of an
Individual Based on a Thermoluminescent Dosimeter (TLD) Readout.
The beta (skin) exposure was reported as 10.002 rem, which
exceeded both the 10 CFR Part 20 limit of 7,500 mrem per quarter
and the Duke Power Company Administrative Skin Dose Limit of
6,000 mrem per quarter. Data from the licensee was subsequently
submitted to the Region concerning the dosimetric aspects of the
13
event.
However, some important radiological aspects did not reach
the Region for evaluation. The licensee's investigation showed
that a Radwaste Operator (RO)
and a Primary Chemist (PC)
had
anomalies on their TLDs for July and focused their investigation
on the overlay of a Unit 3 Deborating Demineralizer in the
auxiliary building on July 14,
1992.
The licensee assigned the
following doses based on their TLD analysis of the data and beta
correction factors. The RO's TLD read 4,959 mrads and 0 mrem
gamma,
and the PC's TLD read 653 mrad beta and 67 mrem gamma.
The
EDC system was implemented primarily to keep track of radiation
dose and maintain a record of a person's access on a RWP. It
showed that July 14,
1992, was the only time that month that the
RO and PC worked together, to add resin to a Unit 3 Deborating
Demineralizer.
TLDs were reviewed to determine if they had been physically
altered, surveyed to determine if contamination had occurred, and
other experiments were conducted to simulate the beta/gamma
component ratios of 50:1. Air samples conducted at the end of the
2-2.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> overlay operation showed eight MPC with the primary
isotopes noble gasses (Krypton and Xenons).
Two HPTs provided
continuous radiological coverage during the job and stated that no
unusual incidents occurred.
Following the job, both individuals
alarmed the PCMs near the job location.
It was determined to be
noble gas after performing a manual frisk with an RM-14 and a
pancake probe.
The RO and PC went to their respective shops after
degassing in front of fan.
After-making a shift turnover, gate
house portal monitors alarmed on both individuals when the RO and
PC attempted to exit the site. They were subsequently released
based on a manual frisk with a RM-14 and pancake probe.
In each
case, HPTs performed the manual frisk and each individual was
determined to be less than 150 ccpm.
b.
Inspection of the Event
On September 1, 1992, after reviewing recent developments based on
the licensee's investigation, the Resident Inspector requested
assistance from the Region. Three Region-based inspectors
responded with the intent of verifying licensee data, root cause
determination, and corrective actions. In addition, the
inspectors were to review aspects of the licensee's program to
prevent a radiation exposure in excess of regulatory limits.
The licensee.provided the inspector with a,
tour of the Unit 3
areas frequented by ROs and PCs in the performance of their
duties. The inspector also interviewed the RO and both HPTs that
participated in overlaying the resin bed in the Unit 3 Deborating
Demineralizer.- The methods used to add resin to the resin bed
were discussed as well as radiological considerations, locations
of airborne and gas radiation monitors, and frisking stations.
14
Based on interviews with licensee personnel who participated in
the resin bed overlay and a review of data, the inspector found
that a number of radiological discrepancies occurred during the
operation. The PC was assisted by the RO since the operation was
physically taxing.
The PC was signed in on RWP 13, Revision 0,
Routine Primary Chemistry Sampling/Analysis (includes
transportation and preparation). The licensee determined that the
PC should have been signed in on RWP 12, Revision 0, Spent Resin
Operations (includes recirculation, sampling, and transfers).
The
RO was not signed in on any RWP at the time the overlay was
performed but subsequently signed in on RWP 12.
RWP 12 required
in the special instructions/precautions section, a pre-job
briefing to be performed.
The licensee was not able to show that
a pre-job briefing had been conducted since neither individual was
on the correct RWP.
This is identified in Paragraph 7.c. as an
apparent violation.
This meant that to determine where the ROs unplanned exposure
occurred, the licensee had to rely solely on the RO's memory to
reconstruct the RO's movements and whereabouts for the month of
July. The inspectors, as well as the licensee, reviewed data for
all personnel in the Radwaste and Primary Chemistry departments to
determine if the EDC system was utilized properly.
Several
individuals did not appear to utilize the system properly,
frequently enough (this included the RO).
However, the inspectors
determined that the majority of the department was checking in on
the EDC system at the start of their shift and checking out on the
EDC system at the end of the shift. The inspector found that two
things contributed to this: 1) the PC group had RWP 13 and the RO
group had RWP 31, Liquid Radwaste Operations, that were almost
always used to perform their required tasks; and 2) Station
Directive 3.3.1 dated November 20, 1991, Personnel Dose-Control,
was not clear on the requirement to use the EDC system on each
individual entry and exit.
While it was determined that July 14, 1992, was the only day that
the RO and PC worked together on a job with the potential for a
significant exposure, the licensee has not been able to state with
any assurance that the unplanned exposure occurred on this date.
As a result of the unusual beta' dosimetry values obtained on TLD
- 400011728 an investigation was performed by the licensee to
determine the most probable cause of the dose and the amount of
the dose.
The inspector independently reviewed the following documents and
conducted independent interviews and event walk through to
evaluate the licensee's final beta dose assignment:
Memorandum to File dated August 16, 1991, Beta Half Value
Layer Determination File No: OS-752-01; OS-752.05
15
Enclosure 5.7 of Procedure HP/O/B/1010/04 titled,
"Respiratory Evaluation" dated August 27,
1992
Memorandum to File dated August 25, 1992, Beta Half Value
Layer Determination File No: 05-752.01; OS-752.05
Memorandum to C. T. Yongue, dated August 31, 1992, TLD Beta
Correction Factor File OS-756.00
Radiation Protection Manual Section 6.6 titled, "Measurement
and Control of External Dose Due to Beta Radiation,"
revision September 8, 1989
Procedure HP/O/B/1008/03 titled,"Procedure. for
Thermoluminescent Dosimeter Quality Assurance Check,"
undated
Performance Summary Report for Third Quarter 1989 Through
Fourth Quarter 1990 by Atlan-Tech, Inc., dated April 1991
National Voluntary Laboratory Accreditation Program (NVLAP)
Current Certificates of Accreditation for ANSI-N13.11
Categories I, II, III, IV, V, VI, and VII
Undated Research Reported titled, "Development of Dose
Algorithms for Low and Intermediate Energy Photons-Using the
Teledyne Isotopes PB-3 Badge Case and CA-S04:
DY Personnel
Dosimetry by E. A. Ballinger"
Computer program Listing for Calculating Personnel Gamma and
Beta Dose Equations written September 29, 1981 with
subsequent revisions including October 18, 1991
Report titled, "Oconee Nuclear Station Units 1, 2, 3, Docket
Nos. 50-269, 270, 287, Unusual Beta Radiation Exposure,"
dated September 30, 1992.
On August 12, 1992, the Oconee Nuclear Station RP staff was
notified of an unusually high beta exposure as read on the above
mentioned TLD badge from the July monitoring period.
The
individual who had been assigned that badge (TLD #400011728) for
July is an Oconee Nuclear Station employee in the Rad Waste
Section of the chemistry group. As part of the investigative
process, the individuals involved were interviewed and various
station documents, records, and logs were reviewed.
Beta dose is determined by the licensee using an in-house TLD
processing facility. As part of this process, the value seen on
the badge that is determined to be from beta radiation is a
fraction of the actual beta dose. To arrive at the actual beta
value, the initial output of the badge, that is determined to be
S
due from beta radiation, must be multiplied by a correction
16
factor. The correction factor is determined from the beta half
value layer (HVL).
The HVL is a density thickness measurement of
the amount of material necessary to reduce a beta dose rate by
one-half. By procedure this measurement is made at the beginning
of each major outage and may vary from one :unit to another and one
fuel cycle to another.
The current beta c6rrection factor used in
processing Oconee's TLDs is 4.8 (a conservative value) and based
on a HVL of 16 mg/cm2 measured from Unit 1 beta activity. A
previous HVL for Unit 3, measured in March of 1991, was 25 mg/cm 2.
The latest value measured for Unit 3, following an extended period
of operation with failed fuel, was determined to be 57 mg/cm
The corresponding correction factor as determined by procedure for
that HVL is 2.38.
The licensee investigation process revealed that tasks performed
by the individual in question, during July, limited their work
locations to the Unit 3 area of the plant and in particular the
Rad Waste Facility. One specific task places the individual in
question working with a Chemistry technician who also received a
beta dose for the month of July.
This beta dose was above the
normal range for Oconee Nuclear Station personnel, although many
times lower than the Rad Waste Technician.
The licensee
established various test conditions to determine if the high beta
to gamma ratio observed on the individual's TLD badge could be
reproduced. These tests revealed that radiation sources
originating from Unit 3 could produce such ratios.
Based on the interviews with the individuals involved, historical
data and TLD testing, the licensee has concluded that the most
probable cause of this beta exposure resulted from a hot particle
or a very small, localized area of surface contamination from
Unit 3.
Based on the licensee's investigations a determination was made
that the beta dose most likely resulted from a hot particle or a
very small, localized area of surface contamination from Unit 3
and the fact that the beta energies for Unit 3 were elevated due
to the presence of failed fuel from January 1992 through the end
of the cycle in July 1992.
The licensee has therefore applied a
beta correction factor of 2.38 to determine a record skin dose of
4.959 Rad to be assigned to the individual.
This correction
factor (2.38) was based on the most current HVL for Unit 3 and was
felt to be more accurate than the previously measured Unit 3 HVL
from March 1991 which does not reflect the activity in the reactor
coolant as a result of the failed fuel.
The inspector, after a review of the supporting data and after an
independent assessment of the event, believes the 4.959 Rad skin,
dose assignment is plausible and technically supportable.
Therefore, there was no regulatory overexposure nor was there an
administrative overexposure.
17
The inspector was concerned as to what extent plant personnel were
not using the EDC system.
A subsequent review of the EDC system
records showed that the RO routinely did not use the dose/RWP
tracking system.
This was identified as an apparent violation in
Paragraph 7.c. The inspector expanded the review of EDC system
records to the Chemistry department which includes radwaste and
primary/secondary chemistry. The review showed that the majority
of the chemistry department checked in on the EDC system at the
beginning of their shift and out at the end of their shift. These
actions would not support the tracking of a person in performing
their duties or maintaining a "real time" record of their dose.
Another contributing factor in not being able to track Radwaste or
Chemistry personnel easily in performing their duties was that
Radwaste primarily used one RWP (#31) and 'Chemistry another (#13)
for the majority of their duties. The inspector reviewed the
controlling procedure for the EDC System Station Directive 3.3.1,
dated November 20, 1991, and found that the procedure was not
clear on whether to use the EDC system on each individual entry
and exit. The inspector concluded that the procedure did not
require or specify EDC system usage necessary to maintain either
real time dose tracking or access on RWPs for jobs. The procedure
was determined to be inadequate and was characterized as an
apparent violation in Paragraph 7.c. As part of the concern about
EDC system usage, the inspector compared monthly thermoluminescent
(TLD) results with monthly pocket dosimeter (PD) doses accumulated
by the EDC system. The intent of the comparison was to identify
individuals whose TLD dose exceeded the PD dose entered in the EDC
system, indicating that the individual may not have been properly
using the EDC system. The inspector noted that the licensee
generallymaintained a 0.6 to 0.7 TLD-to-PD ratio. Also, on
average, only 2-4 individuals per month were indicated to have TL
eand
PD doses that did not correlate within an acceptable range.
Those that were identified were investigated as required.
However, the inspector also noted that PD doses were allowed to
differ by as much as -45% to +70% of the TLD dose before the dose
was isolated and "flagged" for investigation. For example, with a
TLD reading of 100 millirem (mrem), the EDC system could indicate
55-170 mrem for the same time period without a "flag."
Likewise,
for a TLD reading of 2000 mrem, the allowable PD dose was 1900
2500 mrem. In addition, the inspector noted that an individual
could receive 50 mrem per month on a TLD and never have-signed in
on the EDC system because the lower PD dose limit for that TLD
dose was 0 mrem. The inspector informed the licensee that the
wide PD dose ranges limited the usefulness of the system,
especially at the "lower" end of TLD doses. The licensee
indicated that- the ranges were appropriate and did not perceive a
problem with the correlation methods or the EDC system as a whole.
The inspector reviewed licensee procedure.HP/D/B/1000/04,
Change 24, dated December 17, 1991, Issuance, Revision, and
Termination of Radiation Work Permits and Standing Radiation Work
Permits, partly due to a concern that related to the overlay of
18
resin in the Unit 3 Deborating Deminerzlizer; specifically, why
was this operation not performed on a special rather than a
standing RWP. Upon review of the procedure, the inspector found
that the only criteria for requiring a RWP was that the task was
expected to exceed one. person-rem.
The inspector noted that the
overlay of resin in the potentially spent Unit 3 Deborating
Demineralizer was performed on a standing- RWP and that there were
no instructions in the procedure to direct when a special RWP
would be used. In fact, there were no directions in the procedure
for differentiating a special RWP from a standing RWP.
The
inspector found other shortcomings in the procedure and discussed
these observations with licensee management.who agreed to consider
any necessary changes.
The inspector also reviewed the licensee's !instrumentation and
equipment program.
The following procedures were reviewed and
appeared adequate:
HP/O/B/1003/1 6, Procedure for Calibration of Automated
Personnel Monitors, dated January 14,' 1992
HP/O/B/1003/ 22, Calibration Procedure for the Automated
Laundry Frisker, dated June 7, 1988;
HP/O/B/1004/58, Procedure for Calibration of Portable
Instrumentation, dated July 27, 1992. The inspector also
reviewed the licensee's area monitoring system and discussed
its current and future uses. The licensee's equipment
appeared to effectively meet their needs and was maintained
as required.
The inspector discussed the licensee's use of frisking devices for
site release purposes upon receiving portal monitor alarms.
Licensee procedure HP/O/B/1005/11, Response to Personnel and
Clothing Contaminations, allowed-for the use of friskers to clear
individuals for release once they had alarmed the portal monitors.
However, based on discussions with licensee personnel, it appeared
that frisking devices (i.e. RM-14 with pancake probe) were less
sensitive overall than the gatehouse portal monitors that act as
the licensee's "last defense" against unauthorized radioactive
material leaving the site.
In addition, the same procedure:
(1)
recommended that a multi-channel analyzer (MCA) be utilized
when noble gas was suspected to be causing the alarm to verify and
quantify the radioisotope; and (2)
did not require any
documentation of events believed to be noble gas-related.
According to the licensee, due to the relatively high numbers of
apparent noble gas contaminations, an MCA was not routinely
utilized nor were the events documented.
19
c.
Regulatory Implications
TSs 6.4.1 and 6.4.1.g requires that the station shall be operated
and maintained in accordance with approved procedures. Written
procedures with appropriate check-off list and instructions shall
be provided for personnel radiation protection procedures.
Oconee Nuclear Station Directive (ONSD) 3.3.1, Personnel Dose
Control, dated November 20, 1991, requires in Step 3.2, in part,
that work done in a radiation controlled zone or RCA shall be
performed under a SRWP or a RWP.
Contrary to the above, on July 14, 1992, an RO and PC performed
the resin overlay of the Unit 3 Deborating Demineralizer without
being signed on the correct RWP or SRWP. The licensee was
informed that this was an apparent violation of ONSD 3.3.1 and
TS 6.4.1 (50-269, 270, 287/92-17-03).
Duke .Power Company, Oconee Nuclear Station Procedure (ONSP)
HP/0/B/1000/0 4, Issuance, Revision, and Termination of Radiation
Work Permits, and Standing Radiation Work Permits, Change 24,
dated December 17, 1991, is inadequate in that the procedure is
not specific as to when a RWP or a SRWP is needed. The procedure
does not differentiate in criteria for the two. In addition,
field personnel may make changes to the SRWP without
authorizations from supervision and the procedure does not
adequately define what is meant by continuous coverage or
intermittent coverage. This issue was discussed with the licensee
at the exit interview.
ONSD 3.3.1 in Step 3.7 requires that the EDC system shall be used,
when in operation, by individuals to record the pocket dosimeter
dose he/she received for entry or work done under each RWP or
SRWP.
Thorough investigations into the July 14, 1992, job revealed that
two individuals in the Radwaste Chemistry department did not
routinely use the EDC system which is contrary to the above
requirement. This issue was also discussed with the licensee.
The licensee indicated that appropriate changes would be
considered for both issues.
8.
Information Notices (92701)
The inspector determined that the following Information Notices (INs)
had been received by the licensee, reviewed for applicability,
distributed to appropriate personnel, and that action, as appropriate,
was taken or scheduled.
90-48: Enforcement Policy for Hot Particle Exposures
20
88-63, Supp.
1:
High Radiation Hazards from Irradiated Incore
Detectors and Cables
91-36: Nuclear Plant Staff Working Hours
91-37: Compressed Gas Cylinder Missile Hazard
91-39: Compliance with 10 CFR Part 21,
"Reporting of Defects and
Noncompliance"
88-63, Supplement 2:
High Radiation Hazards from Irradiated
Incore Detectors and Cables
91-60: False Alarms of Alarm Ratemeters Because of Radiofrequency
- Interference
91-76:
10 CFR Part 21 and 50.55(e) Final Rules
92-25:
Potential Weakness in Licensee Procedures for Loss of
Refueling Cavity Water
92-30: Falsification of Plant Records
92-37:
Implementation of the Deliberate Misconduct Rule
9. Exit Meetings
a.
August 6, 1992
The inspector met with licensee representatives denoted with a (*)
in Paragraph 1 on August 6, 1992. The inspector discussed the
examples of inadequate posting of radiation controlled zones as an
apparent violation.
As well, the failure to control radiological
operations adequately during cavity drain line piping
decontamination was also discussed.
The inspector also discussed
the increase in hot particle skin contaminations.
The inspector
did not receive any proprietary material or dissenting comments.
Item Number
Description or Reference
50-269, 270, 287/92-17-01
VIO - Two examples of failure to
adequately post RCZs
(Paragraph 6.a).
50-269, 270, 287/92-17-02
VIO - Failure to label Radioactive
Material (Paragraph 6.c).
b.
September 9, 1992
As the result of an unplanned personnel exposure, a second
inspection was conducted. The inspector met with licensee
representatives denoted with a (+)
on September 9, 1992. The item
21
listed below is characterized as an apparent violation of NRC and
TS requirements. Since the licensee investigation was not
complete, the inspector requested a copy upon completion. The
inspector did not receive any proprietary material nor dissenting
comments.
Item Number
Description or Reference
50-269, 270, 287/92-17-03
VIO - Primary Chemist and Radwaste
Operator failed to access a RWP
(Paragraph 7.c).
On October 6, 1992, the inspector received a copy of the completed
licensee investigation. On October 30, 1992, Messrs A. Herdt,
W. Rankin, P. Skinner, and R. Shortridge of the NRC contacted
J. Hampton, D. Sweigart, C. Yongue, M. Patrick and S. Perry at
Oconee Nuclear Station via telephone and discussed the likely
characterization of the inspection report findings.