ML20154F193
| ML20154F193 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/08/1988 |
| From: | Loesch R, Shanbaky M, Weadock A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20154F178 | List: |
| References | |
| 50-317-88-20, 50-318-88-20, NUDOCS 8809190284 | |
| Download: ML20154F193 (6) | |
See also: IR 05000317/1988020
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
Report Nos.
50-317 88-20
50-31 88-20
Docket Nos.
50-317
50-318
License Nos.
Category
C
Licensee:
Baltimore Gas and Electric Company
P.O. Box 1475
Baltimore, Maryland 21203
Facility Name:
Calvert Cliffs Nuclear Power Plant, Units 1 and 2
Inspection At:
Lusby, Maryland
Inspection Conducted:
August. 17-19, 1988
Inspectors:
8. (1/u [
4[6 [I5'
A. Weadock, Radiation Specialist
date
S WA
9hhr
R. Loerch, Radiation Specialist
date
Approved by:
4#. C
[M
9///I
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1. Shanbaky,SectionChief, F4cilities Radiation
date
Protection
Inspection Summary:
Inspect'.on conducted on August 17-19, 1988 (Combined
Inspection Report Nos. 50-317/88-20,50-318/88-20).
Areas Inspected: Unannounced, reactive inspection of events associated with a
higher than anticipated worker exposure on June 21
1988.
This exposure
occurredduringroutinemaintenanceintheUnitIdux111aryBuilding27 foot
elevation valve alley.
Results: One violation was identified:
failure to perform an adequate survey
(see section 3.3).
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DETAILS
1.0 Persons Contacted
1.1 Licensee Personnel
- A. Anuje
Supervisor, Quality Assurance (QA)
- J. Carroll
General Supervisor, QA
- C. Cruse
Manager, Nuclear Engineering Support
Manager'ical Controls Operations Supv. Quality Assurance
- R. Douglass
Radiolog
- J. Lenhart
- J. Lohr
Assistant General Supervisor, Operations
- N. Millis
Radiation Safety General Supv.
- W.
Putnam
Senior QA Auditor
- D.
Shaw
Licensing
ineer
- C. Sly
Licensing
ineer
- L. Smialek
Radiation
trol and Support Asst. Gen. Supv.
- A. Vogel
Technical Training Supv.
1.2 NRC Personnel
- H. Slosson
NRR Project Manaaer
- D. Trimble
Senior Resident Inspector
- Attended the exit interview on August 19, 1988.
Other licensee personnel were also contacted during the course of this
inspection.
2.0 Purpose
The purpose of this unannounced reactive inspection was to review events
associated with the higher than anticipated worker external exposure which
occurred on June 21, 1988.
This exposure occurred during routine
maintenance activities in the Unit 1 Auxiliary Building 27 foot elevation
valve alley.
No regulatory exposure limits were exceeded during this
event.
3.0 Higher Than Anticipated Exposure Event
The inspector evaluated the licensee's identification of and response to
the above higher than anticipated exposure event by the following methods:
- discussion with involved personnel,
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- tour of the Unit 127' valve alley,
- review of associated radiological surveys, log entries, and Calvert
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Cliffs Report (CCR),
- review of Special Work Permit (SWP)"88-003, "Inspections and Minor
Maintenance in High Radiation Areas ,
- review of General Orientation Training lesson plan,
- review of the following procedures:
o RSP 1-101, "Radiological Surveys",
o RSP l-201, "SWP Preparation".
Within the scope of the above review, one violation, concernirg a failure
to perform an adequate survey, was identified and is discussed below.
3.1 Event Summary
On June 21, 1988, two maintenance workers entered the Unit 1 27' valve
alley, a locked and posted High Radiation Area (Special Work PermitHRA), to lu
No.68-003, "Inspections and Minor Maintenance in High Radiation Area (SWP)
rod linkage fittings. The workers signed in on
s."
leted
The most recent routine radiological survey for the valve alley, comp /hr at
on June 9,1988,k location inside the valve alley. indicated general area radiation dos
the presumed wor
The valve alley was
also posted as a contaminated area, with the boundary and step-off pad
located just inside the locked doorway.
ThetwoworkersmetwiththeareaRadiationSafetyTechnician(RST)lvewho
performed a brief, "spot check" survey inside the doorway of the va
alley to verify the previous survey readings. The two workers equipped
with their own survey meter,
then entered the valve alley and, worked for
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a) proximately 5 minutes. Anticipated exposure for this work entry was less
t1an 15 millirem. Upon exit, the workers read their pocket dosimeters
which indicated they had received 60 and 130 millirem, respectively.
The
workers notified the area RST.
in the valve alley and identified a
The RST 1mmediately performed a survey /hr located on a CVCS valve and
hot spot reading approximately 50-70 R
adjacent piping in the 13 CVCS ion exchanger discharge line, approximately
five feet from the work area. Although not recorded (see section 3.3),
survey measurements made in the work area adjacent to one of the
chest-level linkage fittings ranged from 800-2000 mR/hr, approximately
15-40 times the assumed dose rates. The RST then posted the valve alley as
an exclusion area, restricting all access.
Subsequent surveys performed by
a Radiation Control supervisor
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identified contact dose rates ranging from 30-70 R/hr on the valve and
short segment of CVCS piping, with 18 inch dose rates from 3-5 R/hr.
3.2 Licensee Followup
Licensee follow-up actions to the above event included the following:
Flush of the CVCS valve and piping on July 7, 1988.
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Immediate initiation of an investigation into circumstances leading to
the event. The investigation was conducted by a QA auditor with
previous health physics experience.
The investigation and findings
which was submitted
to the p'lant safety review committee (PSORC CCR) August 4, 198
were documented in a Calvert Cliffs Raport
on
The
auditor s review included interviews with t e maintenance workers, the
RST, review of related surveys, and observation of the work area.
The CCR was not submitted to PSORC until August 4, 1988, approximately
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six weeks after the incident. At that time, there was disagreement
between the CCR investigator and the RC staff as to whether an
inadequate survey had been performed.
It was not until the Assistant
General Supervisor, Radiation Control and Support, interviewed the
involved RST during the week of the NRC inspection, that the RC staff
concurred with the CCR.
The licensee's Radiation Safety Technicians were not briefed
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concerning details of the event until the week of the inspection.
As of August 19, 1988, the RC staff had not independently interviewed
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the two mi.intenance workers concerning the event. NRC interview of the
two workers identified significant discrepancies between the accounts
of the RST and the workers.
Followup surveys of the valve alley were not performed by the RC staff
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until August 15, 1988, several weeks after the valve was flushed.
3.3 NRC Review
10 CFR 20.201, "Surveys", requires the licensee to make such surveys as are
necessary to comply with the regulations in 10 CFR 20 and are reasonable to
evaluate the extent of radiation hazards that may be present.
The
inspector determined through interview of the involved RST that the
pre-work survey performed on June 21, 1988, was made just inside the
doorway to the valve alley, rather than in the area in which the
maintenance workers would be working, approximately six feet away.
Subsequent measurements identified that area dose rates in the work area
were much greater than antici)ated and that the presence of a significant
radiation hazard (50-70 R/hr lotspot) was unknown at the time work was
initiated.
Failure to perform an adequate survey of the work area
constitutes an apparent violation of 10 CFR 20.201 (50-317/88-20 01).
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The inspector noted the licensee's CCR identified the pre work survey as
inadequate, and therefore this violation potentially qualifies for
enforcement discretion as a licensee-identified violation as provided for
in 10 CFR 2, App. C.
Qual;fication for such discretion requires the
apparent violation to meet several conditions, including the requirement
that measures to prevent recurrence be completed within a reasonable period
of time.
The inspector stated that mitigation of the violation was not a propriate
as the QA auditor's findings relative to the inadequate radiolo ical survey
were being refuted by the RC group rather than initiating promp and
aggressive action to prevent recurrence.
The licensee stated their immediate corrective actions were directed at
posting and access control of the valve alley and hot spot and that these
actions were done in a timely fashion. The inspector acknowledged the area
was quickly and effectively controlled. The inspector also stated that the
poor survey practices exhibited, whether practiced on an individual or a
widespread basis, represented a significant concern in radiological work
control which should have been quickly addressed and corrected.
The following additional concerns were also identified during this review:
The use of a broad-scope, routine SWP for work in the valve alley was
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inappropriate.
Licensee procedure RSP 1-201, section 3.6, states that
routine SWPs are designed to allow access to controlled areas for
activities involving minimal or clearly defined radiological hazards.
The inspector noted that the valve alley is an area with the potential
for rapid and dramatic changes in area dose rates, based on radwaste
operations. The licensee indicated that the use of a routine SWP for
this and other HRAs would be evaluated. The licensee also stated that
the use of additional controls over work in HRAs (i.e., continuous
coverage) was being evaluated.
The pre-job surve performed by the RST was not documented. As this
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survey is the sub eet of one cpp(arent violation, no additional
citation against 0 CFR 20.401
i.e., failure to maintain survey
records
is warranted.
The inspector noted however add
examples)ofweaknessesinsurveydocumentatIonpractices.itional
Area dose
rate measurements in the ) resumed work location were apparently taken
after identification of tie hotspot and were stated to the inspector
however, these measurements
asbeing800and2000mR/hrrespectivelylsorecentlyimplementedthe
were not documented. The licensee has a
use of a "work ticket" form that accompanies the work party and
requires the area technician to document survey measurements on the
form.
The inspector noted the use of this unproceduralized form is
inconsistent; although it was used for similar activities in the valve
alley on previous days it was not used on June 21, 1988, for the
subject incident.
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NRC interview of the RST and the two workers identified significant
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inconsistencies concerning the level of the pre-job briefing and the
scope of work to be performed. A specific inconsistency of concern is
whether it was known that the workers would be climbing pipes in the
overhead, an unsurveyed area to reach two fittings 13 feet off the
floor. AsoftheweekofthIsinspectionthelicenseehadnot
followed up on this concern.
The licensee indicated that the investigation into activities
surrounding the incident was still continuing and the above concern
would be evaluated.
No formal dose assessment had been performed by the licensee to
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evaluate whether the worker's dosimetry placement was adequate to
monitor exposure to the unanticipated hot spot, and whether
adjustments to the recorded dose were necessary.
The licensee
indicated that the survey of the valve performed by tb3 RC supervisor
on June 21, 1988, indicated that the hot spot represented a whole body
exposure source to the workers and was adequately monitored by the
worker's TLDs. This was due to the consistency in dose rates, and the
valve's location and inaccessibility. No follow up to this initial
assessment, however, such as interviewing the workers concerning their
location or survey of the valve alley general areas prior to the
hotspot flush was performed. The inspector concluded, based on visual
inspection of the valve alley that the licensee's dose assessment of
60 and 130 mrem for the two workers was appropriate. The licensee
stated that the maintenance workers would be interviewed concerning
their movements to determine if the licensee's initial assessment
remained valid.
Licensee evaluations and any additional actions addressing the above
concerns will be reviewed in a subsequent inspection.
4.0 Exit Meeting
The inspector met with licensee re)resentatives, denoted in Section 1.0 of
this report, on August 19, 1988. Juring this meeting the inspector
summarized the purpose, scope and findings of the inspection.
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