IR 05000317/1994018
| ML20029E327 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/04/1994 |
| From: | Bores R, Joseph Furia NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20029E324 | List: |
| References | |
| 50-317-94-18, 50-318-94-18, NUDOCS 9405180158 | |
| Download: ML20029E327 (6) | |
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
50-317/94-18 Report No.
50-318/94-18 50-317
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Docket No.
DPR-69 Licensee:
Baltiniore Ga5_;ind Electric Company Post Office Box 1475 Baltimorg. Maryland 21203 Facility Name:
Calvert Cliffs Nuclear Power Plant. Units 1 and 2 Inspection At:
Lusby. Maryland Inspection Conducted:
bpril 25-29.1994 e
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Inspector:
w *M sw r/2/fy J. Ily'ria, Senior Radiation Specialist date Approved by:
u
- /oy'/97 R. Bores, phief, Facilities Radiation date Protection Section AmtLDLspected: Maintaining occupational exposures as low as reasonably achievable (ALARA), outage operations and assurance of quality.
Itemtlls: ALARA initiatives and improved ALARA planning for the Unit 1 1Ith refueling outage (RF-11) appear to be more successful than those taken during the past two years.
Ilowever, continued improvement is required in the area of ALARA, especially in regard to scaffold control and identification for work involving In-Service Inspection. One non-cited violation in the area of failure to follow procedures by a contractor health physics technician was also identified.
9405180158 940506-DR ADOCK 05000317 PD.
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DETAILS 1.0 Personnel Contacted 1.1 Licensee Personnel
- P. Chabot, Superintendent, Technical Support W. Coursey, ALARA Technician
- C. Cruse, Plant General Manager
- G. Detter, Director, Nuclear Regulatory Matters
- C. Gradle, Compliance Engineer
- S. Hutson, Supervisor, Radiation Control - Operations M. Patton, Training Instructor
- W. Paulhardt, Supervisor, Radiation Control - Operations
- G. Phair, Assistant General Supervisor, Radiation Control and Support
- M. Rigsby, Assistant General Supervisor, Radiation Services W. Sullivan, Quality Assurance Specialist
- B. Watson, General Supervisor - Radiation Safety
- R. Wyvill, Supervisor, Radiation Control - ALARA 1.2 NRC Personnel
- K. Lathrop, Resident Inspector
- C. Lyon, Acting Senior Resident Inspector
- Denotes those present at the exit interview on April 29,1994.
2.0 Previously Identified Items (Closed) Unresolved item (50-317/94-10-01; 50-318/94-10-01) Contractor health physics technician failed to follow Calvert Cliffs radiation control procedures leaving a lock and chain unsecured after exiting a posted Locked High Radiation Area.
Subsequent NRC review has determined that this item is a non-cited violation as described in Section 3.2 below. This item is closed.
3.0 Radiation Safety At the time of this inspection, the licensee had nearly completed its lith refueling outage at Unit 1 (1-RF-11). More than half of the contractor health physics technicians hired for this outage had been released, and the principal task assigned for the Radiation Controls - Operations Section was to allow for closure of the containment. Staffing levels for this phase of the outage appeared adequate.
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3.1 Maintaininy Occupational Exoosure ALARA Prior to the start of 1-RF-11, the licensee established an outage exposure goal of not more than 300 person-rem. At the end of April 28,1994, total outage exposure was 367.2 person-rem, and the ALARA staff anticipated final exposure for the outage to be 370 person-rem. There appeared to be three major components that led to the licensee exceeding its original exposure goal by more than 20%. These were emergent work due to unanticipated system failures and system repairs, emergent work due to poor craftsmanship by key contractors and failure to plan properly for In-Service Inspection work prior to the outage.
During the course of the refueling outage, several system failures and unanticipated system repairs occurred, the repairs of which significantly contributed to the outage exposure total. During testing of the reactor coolant pumps after closcout of the steam generator testing and repair work, coolant pump 12A had a catastrophic failure. Repairs to this pump motor were anticipated to add 10 person-rem to the outage exposure. During a system engineering walkdown of the chemical and volume control system, missing pipe supports near valves CVC-515 and CVC-516 were identified. Replacement of these missing pipe supports added approximately 1.4 person-rem to the total outage exposure. During a forced outage at Unit 2 during January 1994, a failure of the pressure indicator system for the inner 0-ring of the reactor cavity was discovered and repaired. Since a similar system was also used at
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Unit 1 (PIA-118), similar repairs were added to the outage, resulting in an additional 10.6 person-rem of exposure.
i Poor quality of workmanship was a significant contributor to total outage exposure, especially in the areas of steam generator, pressurizer and neutron shield work.
During steam generator tube plugging, the robotics system used to place steam generator tube plugs repeatedly failed, requiring human intervention to assist the robot. Additionally, the robot fell inside one of the steam generators, breaking open one of its hydraulic lines, leaking approximately two gallons of hydraulic fluid into the bowl of the steam generator. The licensee estimated a minimum of 2.8 person-rem of additional exposure was expended for rework alone in the steam generators, due to poor quality of work.
In the pressurizer project, the licensee was attempting to provide a nickel coating to the inner surfaces of the pressurizer to prevent stress corrosion cracking of the pressurizer heater sleeves. Repair and replacement of the heater sleeves at Unit 2 required more than a year's worth of work and 120 person-rem of exposure. The nickel plating project was estimated at 40 person-rem, and could be accomplished within the scope of the licensee's approximately 90-day outage. General area dose rates under the bowl of the pressurizer were expected to be 65 milliroentgens per hour (65 mR/hr) prior to decontamination and shielding of the pressurizer area, however upon initial entry, dose rates were found to be 85-120 mR/hr. An inability
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to create a freeze seal for the pressurizer decontamination and an unexpected sludge trap in the bottom of the pressurizer bowl led to a total exposure of 17 person-rem just to decontaminate the pressurizer prior to the commencement of work. Despite this, the total job appeared finished at just below the pre-outage goal of 40 person-rem. Upon drawing a bubble in the pressurizer during system testing, however, a leaking heater sleeve, with a swelled heater that could not be readily replaced, required rework in the pressurizer, adding approximately 4 person-rem to the total project exposure.
For this refueling outage, the licensee added the plant modification of a new neutron shield. Neutron exposure has been a significant concern at Calvert Cliffs since original plant start-up, and the neutron shield represented the culmination of 15 years of planning and design. The pre-outage exposure goal for the installation of this new shield, and the placement of a new pool seal was 15 person-rem. Actual exposure was approximately 19 person-rem. Difficulties in fitting the shield sections properly in the reactor annulus despite extensive measurements taken several years earlier to prevent just such problems, and poor workmanship during the welding of the pool seal were identified by the licensee as the causes of this additional exposure.
In-Service Inspection (ISI) in the containment was estimated to be 9.5 person-rem prior to the start of the outage. This work was completed for less than 6 person-rem.
However, these exposure goals and actual totals do not include the scaffold and insulation work necessary to support the actual ISI testing. Total exposure for scaffold and insulation work was approximately 47 person-rem, well above the 17.5 person-rem for miscellaneous refueling work and 20 person-rem for minor maintenance established as outage goals. Approximately 70% of the scaffold / insulation exposure was directly related to the support of ISI work, according to the licensee. A review of the licensee's outage preparations for ISI work, together with discus. cions with ALARA personnel indicated that a significant contributor to this poor performance was a failure to communicate properly with the ISI organization when establishing exposure goals and performing an ALARA review piior to the outage. While ISI identified 300 test points within the containment where approximately 500 tests would take place, the ALARA Section failed to accurately understand where the test points were located, and had little input into the scheduling of these tests to minimize exposure, and aid in ensuring appropriate coordination in the erection and use of scaffolding in the containment.
In spite of the weaknesses noted above, several outage activities were conducted very successfully from the ALARA viewpoint. These include: the refueling path, which finished 9 person-rem under budget; decontamination of the in-core instrument (ICI)
flanges, which was accomplished for 8 person-rem less than that used during 2-RF-09 at Unit 2 in 1993; and use of new steam generator nozzle dams, which saved 6.5 person-rem. In addition, in general ALARA and outage planning was considerably improved over the past two refueling outages. The level of ALARA reviews
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1 conducted of work in progress was greatly expanded, and the overall outage planning was significantly increased. Continued significant efforts by the licensee need to be made, however, in order for outage planning to continue to improve, and as a consequence minimize personnel exposure.
3.2 Radioloeical Operations i
During this inspection, tours of the radiologically controlled area (RCA), especially in the auxiliary building and the containment, were made. At the time of this inspection, final testing and closcout of the work in the containment was being
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conducted. The 45' elevation appeared to have been fully cleaned, while only small areas of the 10' and 69' elevations required any additional work prior to containment closure.
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As described in NRC Inspection Report Nos. 50-317/94-10; 50-318/94-10, on March 29, 1994, a contractor health physics technician (HPT), covering work in the head laydown area, failed to chain and lock the entrance to this area following the completion of work for which the HPT was providing coverage. The head laydown area was posted as a IAcked High Radiation Area. Approximately 10 minutes after
the HIrr left the area unlocked, a group of radiation safety staff members, conducting a walkdown of the containment, discovered the discrepancy, and took immediate actions to secure the area. No entry to the area was made while the area was not locked. Subsequent investigation by the licensee, and review by the NRC indicated that this area was under closed circuit television surveillance by a dedicated HPT located a short distance away on the same level as the head laydown area during the period of time that the area was unlocked. This surveillance was set up in part to maintain appropriate control over the Locked High Radiation Area access point. The contractor HPT's failure to lock the area access point was a violation of the licensee's radiation control procedures. Compliance with radiation control procedures is required under Plant Technical Specification 6.11. The licensee's corrective actions included taking disciplinary action against the contractor, installing a new gate at the access point to the head laydown area, evaluating all High and Locked High Radiation Area entrance points throughout the plant, and initiating changes to the procedures for access to Locked High Radiation Areas to incorporate a double verification system when locking the area. Due to the licensee's self-identification of the event, low safety significance of the event, prompt corrective actions and thorough investigation of the event, in accordance with Title 10, Code of Federal Regulations, Part 2, Appendix C, this event is classified as a non-cited violation.
During this inspection, direct observation of a shipment of spent mechanical filters was made. The license loaded these filters into a polyethylene liner located in the spent resin cask pit, then transferred the liner into a Chem-Nuclear Systems, Inc.
shipping cask. Radiation controls for this evolution were determined to be thorough, and all operations conducted were closely monitored by the radiation controls staff.
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One weakness was identified during these observations, and discussed with the licensee staff. It involved a 45-minute delay in bringing the shield cask containing the liner out of the spent resin pit and on to a truck in the spent resin processing area.
The cask was left attached to the crane hook, and suspended over the spent resin pit while discrepancies in the transfer procedure were addressed. The licensee recognized after the fact that this was not a " safe storage" configuration, and that the cask should have been lowered back down into the spent resin pit while the procedural problem was resolved.
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3.3 Assurance of Ouality As part of this inspection, a review of licensee Surveillance Reports of activities conducted during the outage was undertaken. Three Surveillance Reports were issued for work in the steam generators, one each during nozzle dam installation, eddy current testing, and tube plugging. While these surveillances were not specifically aimed at radiological controls and operations during these evolutions, these topics were examined and documented in the reports.
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The Surveillance Reports were in addition to the ALARA reviews conducted during the outage. During all entries made into the containment by the inspector, an ALARA specialist was observed conducting a work review. These reviews were documented, and are to be used by the licensee in preparing a post outage ALARA review. This post outage ALARA review is scheduled to be issued by mid-summer,
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and will be reviewed by the inspector during a future inspection in this area.
4.0 Exit Interview
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The inspector met with the licensee representatives denoted in Section 1 of this report at the conclusion of the inspection on April 29,1994. The inspector summarized the purpose, scope and fmdings of the inspection. The licensee acknowledged the fmdings of the inspection.
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