IR 05000317/1988020
| 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 | |
| Preceding documents: |
|
| Download: ML20154F193 (6) | |
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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.
DPR-53 Category C
DPR-69 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:
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A. Weadock, Radiation Specialist date S WA 9hhr R. Loerch, Radiation Specialist date Approved by:
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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
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 inciden. _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _
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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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