IR 05000374/1993029
| ML20057F971 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/13/1993 |
| From: | Louden P, Paul R, Pederson C, Charles Phillips, Snell W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20057F968 | List: |
| References | |
| 50-374-93-29-EC, NUDOCS 9310200033 | |
| Download: ML20057F971 (25) | |
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U. S. NUCLEAR REGULATORY COMMISSION
REGION III
i Report No.
50-374/93029(DRSS)
Docket No.
50-374 l
l License No. NPF-18 Licensee Commonwealth Edison Company Executive Towers West III 1400 Opus Place, Suite 300 Downers Grove, IL 60515 Meeting Conducted: October 5, 1993 Meeting Location:
Region III Office 799 Roosevelt Road Glen Ellyn, IL 60137 Type of Meeting:
Enforcement Conference Inspection Conducted:
LaSalle Site
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Marseilles, Il l
September 8 to 14, 1993 Inspectors:
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P. Louden Date ~
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l LK. Paul Date
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7 C. Phillips Date '
Reviewed By:
// ),[Mf_ (aff'
,of,,/g William Snell, Chief Ilat'e Radiological Controls Section 2 Approved By:
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/n// ?/93 Cygth~ia D. Pederson Chief Da~te'
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R4 actor Support Programs Branch Meetina Summary:
Enforcement Conference on October 5. 1993 (Report No. 50-374/93029(DRSS))
Areas Discussed: Three apparent violations and several programmatic 9310200033 931013 DR ADOCK 0500
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weaknesses identified during the special reactive inspection were discussed.
The three apparent violations concerned:
(1) failure to perform an adequate i
evaluation of radiological hazards incident to workers, contrary to 10 CFR 20.201(b); (2) failure to use engineering controls to mitigate the creation of an airborne radioactivity area, contrary to 10 CFR 20.103(b)(i); and (3)
failure to follow radiation protection procedures, contrary to Technical Specification 6.2.B.
The programmatic weaknesses concerned:
Management oversight of in-plant activities was inadequate to
ensure that expectations were being met and that work was being I
accomplished in an acceptable manner.
An ineffective pre-job meeting in which communication problems e
inhibited clear identification of the nature and scope of work to all parties involved with the evolution.
Poor radiation worker and radiation protection technician
performance during the disassembly.
Ineffective long term corrective actions which were developed to
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address continuing radiation worker and radiation protection technician performance problems.
The conference also included a discussion of two events which occurred subsequent to the inspection which involved three minor intakes of radioactive material received by workers performing a Control Rod Drive filter changeout, and the creation of a 90 R/hr hot spot in the bottom of the reactor vessel
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during Local Power Range Monitor work being conducted on the refuel floor.
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J DETAILS 1.
Persons Present at the Enforcement Conference Commonwealth Edison Company W. Murphy LaSalle Site Vice President j
J. Schmeltz LaSalle Acting Station Manager
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L. Oshier LaSalle Health Physics Services Supervisor
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J. Lockwood LaSalle Regulatory Assurance Supervisor T. Nauman LaSalle Master Mechanic F. Rescek Corporate Director, Radiation Protection J. Burns Regulatory Performance Administrator
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S. Barrett Byron Health Physics Services Supervisor l
S. Trubatch Attorney V. S. Nuclear Reaulatory Commission H. Miller Deputy Regional Administrator W. Axelson Director, Division of Radiation Safety and Safeguards W. Snell Chief, Radiological Controls Section 2 R. Hague Chief, Reactor Projects Section 1C D. Hills LaSalle Senior Resident Inspector J. Kennedy LaSalle Project Manager, NRR P. Louden Radiation Specialist i<. Paul Senior Radiation Specialist A. McMurtray Reactor Engineer i
T. Kozak Senior Radiation Specialist B. Bersen Regional Counsel l
P. Pelke Enforcement Specialist D. Carter Radiation Protection Specialist, NRR
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Enforcement Conference An enforcement conference was held in the NRC Region III Office on October 5, 1993.
This conference was conducted as a result of the preliminary findings of the inspection conducted from September 8 to September 14, 1993, in which apparent violations of NRC regulations were identified.
Inspection findings were documented in Inspection Report 50-374/93025(DRSS), transmitted to the licensee by letter dated September 27, 1993.
The purpose of this conference was to (1) discuss the apparent violations, their causes, and the licensce's corrective actions; (2)
determine if there were any escalating or mitigating circumstances; and (3) obtain any information which would help determine the appropriate enforcement action.
Following an introduction by the Director of the Division of Radiation Safety and Safeguards, the following apparent violations were presented:
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(1)
failure to perform an adequate evaluation of radiological hazards incident to workers, contrary to 10 CFR 20.201(b)
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failure to use engineering controls to mitigate the creation of an airborne radioactivity area, contrary to 10 CFR 20.103(b)(i)
(3)
failure to follow radiation protection procedures, contrary to Technical Specification 6.2.B.
The following programmatic weaknesses were presented:
Management oversight of in-plant activities was inadequate to
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ensure that expectations were being met and that work was being accomplished in an acceptable manner.
An ineffective pre-jeb meeting in which communication problems
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inhibited clear identification of the nature and scope of work to
all parties involved with the evolution.
Poor radiation worker and radiation protection technician
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performance during the disassembly.
Ineffective long term corrective actions which were developed to l
address continuing radiation worker and radiation protection technician performance problems.
The licensee's representatives described the events which led to the apparent violations, including root causes and corrective actions taken immediately following the event.
During the conference the licensee did not deny apparent violation #3
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but did express reservations about one example of the apparent violation concerning procedural requirements to wear respirators.
Specifically, it was stated that respirators were not procedurally required based on the contamination levels in the immediate work area defined by the responsible Radiation Protection Technicians (RPTs).
The NRC maintains that respirators were procedurally required because (1) the RPTs were in error in their definition of the immediate work
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area and contamination levels exceeded 100,000 dpm/100 cm' in an area i
which should have been included as the immediate work area; and (2) as found in an RPT log sheet, contamination levels exceeded 100,000 dpm/100
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cm' on the studs and nuts which were in the area defined as the immediate work area by the RPTs.
i At the conclusion of the meeting, the licensee was informed that they would be notified in the near future of the final enforcement action.
Attachment:
Commonwealth Edison Company handouts
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OCTOBER 5,1993 LASALLE ENFORCEMENT CONFERENCE
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REFUEL FLOOR CONTAMINATION EVENT
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AGENDA INTRODUCTION W. P. MURPHY 95/93 CONTAMINATION EVENT L. L. OSHIER OTHER RADIOLOGICAL EVENTS L. L. OSHIER CRD FILTER LPRM REMOVAL PROGRAMMATIC CONCERNS J. V. SCHMELTZ CULTURE ASSESSMENT J. V. SCHMELTZ CLOSING W. P., MURPHY a
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Intmduction Warren Murphy
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Introduction of Staff:
Joe Schmeltz Chip Oshier Tom Nauman John Lockwood
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The 9/7/93 refuel floor contamination event did result in violations and reveals opportunities for improvements / enhancements. Fortunately, the event had no safety significance, no regulatory or administrative limits were exceeded.
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The Radiation Protection (RP) Program has been a subject of attention for some time.
Enhancements have been made, and overall the program is improving. A review of prior corrective actions shows that they generally have been effective and could not have been expected to prevent this event. Additional corrective actions and program enhancements have been initiated and are ongoing as a result of this event. We will continue to aggressively upgrade the RP program.
Our principal focus now is on identifying and addressing the cultural and programmatic factors which continue to adversely impact radiation work practices both by plant workers and radiation department personnel. A cultural assessment is underway and some preliminary results have been obtained which show that most workers understand that they are responsible for their own radiation safety. We
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recognize that we still have work to do to attain a superior radiation protection program. Our steps in this direction will be discussed in detail along with our analysis of this event and the other two more recent events.
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9/7/93 Refuel Floor Contamination Event Leonard Oshier Background Several months before the outage, a team was assembled to look for ways to improve RP performance both in the preparation and conduct of work. The participating RP technicians were empowered to make decisions to implement identified improvements. One improvement identified and adapted was the lead technician concept. It empowers workers to make
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decisions on jobs they are covering, and provides for self d:rected teams. Two areas were proposed: the Drywell and the Refuel Floor. Drywell expectations were documented and communicated to the participating individuals. The Refuel Floor expectations were documented but were not communicated properly due to a disability of the program implementer. Management acknowledges a failure to adequately compensate for the disabled individual and to ensure complete implementation of the concept for the Refuel Floor (RFF).
Preparation (ALARA Review)
Preparation for the RFF work began with the RP outage committee which included RP workers and management. The new leader did review experience and lessons learned from other outages (including inputs from mechanical maintenance). The job had been performed successfully by having more than one crew using all of these air tools in the cavity at the same time.
It was also determined that strippable coating had not worked effectively as a decontamination measure in the previous outage. Therefore it was not used.
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Lead / water had been used in Unit 1 to control dose by providing shielding. It was planned to be used here, but after initial surveys, it was found unnecessary because it would not reduce dose significantly. Before this event, neither lead nor water was recognized as a means to control the potential airborne dispersal of " crud" stirred up by air driven tools.
Pre-Job Briefing On the morning of the day of the event mechanical maintenance supervisors and bargaining unit / Radiation Protection Technicians (RPT) discussed the work for the upcoming shift. A video tape of stud removal was reviewed, the Mechanical Maintenance (MM) supervisor narrated.
The RPTs discussed the scope of the Radiation Work Permit (RWP) clothing required and cavity conditions.
The lead RPT discussed the air tools with the mechanical maintenance supervisor -
focus on the need for respirators.
Smears were < 100 K dpm/100 cm in the primary work area.
This work was done in previous outages without respirators.
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The air sample on the prior shift showed < 0.25 MPC.
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Decided that face shielding vas sufficient to protect from splashing of oil which
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had been put on the studs to control contamination (done successfully before).
We acknowledge that they failed to redize the effect of air tools on the crud under the
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grating.
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i Work Conduct
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The crews entered the cavity in sequence to do sqes of work using air handling tools. The workers observed a puff when a stud was broken loose. Puffs like these are routinely seen due to dried graphite breaking free. Experience shows that they did not cause a
contamination control problem. Thus, there was no reason for workers to be concerned that there could be a different source of radiological contamination. We recognize that mistakes
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failure did not meet our expectations. 3 continuous air monitors (CAMS) on the refuel floor
- none near cavity - also did not meet our expectations for trained, qualified RPTs.
Ventilation was turned off based on work scope and cavity conditions. All work groups were involved in the meeting where the decision was made. No objections were raised. The decision only affected the extent of consequences of the event. The decision would have
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been correct if contamination under the grating had been controlled.
TN natch was covered and taped as had been done in previous outages.
That taping had been adequate previously but in fact, was not adequate when the ventilation was turned of'
and then back on. Thus, the team would have had no reason to suspect that shutting off the I
ventilation would cause leakage when turned back on.
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Ventilation was restarted because the refuel floor coordinator and shift engineer believed that t
the observed increase in contamination was due to shutoff of the ventilation. At that time the ventilation shutoff was seen as the only difference from previous outages. Restart of the ventilation spread contamination through the hatch and elevator shafts.
l Despite this incident, the total exposure for the entire job of disassembling reactor head was only 8 Rem as compared with 11 Rem previously.
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l Post-Contamination Response 22 individuals were contaminated,18 of these were on the refuel floor at the time. The
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individuals were decontaminated. No administrative limits were exceeded. An investigation
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began immediately. The Acting Station Manager elevated it to a Level 2 investigation in
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accordance with the Integrated R.eporting Program, (IRP). The Investigation Team determined
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?kat the root cause was the failure to identify that the contamination under the grating and bellows area lead to spread of contamination due to air handling tools, which led to a failure to evaluate how the decision not to shield the grating could be affected by the use of air
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driven tools. Work on the refuel floor was resumed after the Acting Station Manager, Radiation Protection Manager and the Contamination Control Coordinator determined that i
work could continue safely under certain conditions / restrictions. These extra actions will be reviewed for continuing applicability prior to the next refueling outage.
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VIOLATION l
The failure to perform an adequate survey to eva!aate radiological hazards incident upon workers is an apparent violation of 10CFR20.201(b).
- Consequences of using air tools not evaluated.
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b. Continuous Air Monitors (CAM) improperly placed.
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Root Cause RP management's incomplete implementation of the lead Technician on the RFF resulted a.
in a failure to consider that crud under the grating could be dislodged by the use of air tools if no lead / water shielding was used for dose control purposes.
b. RP Tech error.
Corrective Action al Lead Tech program for Refuel Floor will be implemented by a qualified manager. RP department will develop clear guidance with expectations of Lead Technician concept and provide appropriate training when necessary.
a2 Management will ensure that continuity is provided when new programs are implemented, bl RPM conducting one-on-one discussions with RPTs reviewing the event and expectations.
b2 Review of this event will be added to RPT initial and continuing training. As used at LaSalle, continuing training means that the event is covered one time to ensure all the current RPTs review the event.
b3 Insight from the cultural assessment will be applied to the programmatic assurance of basic RPT performance.
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Other Actions Two-person RP team, one Corporate and one offsite station person, reviewing package preparation for jobs involving high dose and/or contamination for incorporation of lessons learned.
A Corporate person is reviewing the effectiveness of administrative controls and a process for program improvement for pre-job planning.
Develop administrative controls guide for the refuel floor.
RP Refuel Floor manager assigned.
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VIOLATION
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Failure to use engineering controls to mitigate or limit the creation of an airborne radioactive area is an apparent violation of 10CFR20.103(b)(1).
Consequences of using air tools not understood and compensated for (HEPAs and a.
diffusers).
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Root Cause RP management's incomplete implementation of the Lead Technician conce pt resulted in a
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failure to consider that crud under the grating could be dislodged by the us: of air tools if
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no lead / water shielding was used for dose control purposes.
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Corrective Actions
al Lead Tech program for Refuel Floor will be implemented by qualified manager. RP department will develop clear guidance with expectations of Lead Technician concept and provide appropriate training when necessary.
a2 Management will ensure that continuity is provided when new programs are implemented.
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bl RPM conducting one-on-one discussions with RPTs reviewing the event and expectations.
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b2 Review of this event will be added to RPT initial and continuing training. As used at i
LaSalle, continuing training means that the event is covered one time to ensure all the current RPTs review the event.
b3 Insight from the cultural assessment will be applied to the programmatic assurance of
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basic RPT performance.
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Other Actions
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Two person RP team, one Corporate and one offsite station person, reviewing package preparation for jobs involving high dose and/or contamination for incorporation of lessons learned.
A Corporate person is reviewing the effectiveness of administrative controls and a process for program improvement for pre-job planning.
d Develop administrative controls guide for the refuel floor.
Reconsider needs for localized ventilation units during Reactor vessel disassembly.
For all RFF activities, a HEPA unit, or other exchange mechanism, will be placed in the cavity for air exchange purposes.
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VIOLATION
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Failure to follow radiation protection procedures is an apparent violation of Technical Specifications 6.2.B which requires, in part, that radiation protection procedures be followed.
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Air sample not taken to support non-use of respirators despite contamination levels a.
exceeding 100K dpm/100 cm
b. Inadequate sealing of hatch under work conditions.
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Root Cause In the spirit of focusing our energies on corrective actions, we will not contest this a.
example. We acknowledge that the procedure on non-use of respirators could be literally read to require the taking of an air sample whenever any spot in the work area, no matter
how small or far from the work, exceeds 100K dpm/100cm. That has not been the station's consistent interpretation.
b. Previously unrecognized poor work practice masked by ventilation effects.
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Corrective Actions Revise LRP 1310-4 to clarify criteria in procedure where respirators are required in a.
situations exceeding 100K dpm/100cm,
b. Train workers to ensure adequate sealing independent of ventilation.
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SAFETY SIGNIFICANCE Minimal because no administrative or regulatory limits exceeded.
l Based on our calculations th-nighest committed dose equivalent was 42 mrem.
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OTIIER EVENTS
While the investigation results are still under review, other corwetive actions may be under consideration and may be pursued upon completion of the event investigations.
Control Rod Drive (CRD) filter Change out Weakness - failure to perform contamination survey prior to removing individual from
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respirator.
Root Cause - Incomplete pre-job planning.
Immediate Corrective Action - investigated, identified weakness, and communicated
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Long Term Corrective Action - Expectations are to document decision process. Corporate to review pre-job planning. The RPM will hold one-on-one coaching sessions with technicians, small group sessions with management.
Local Power Range Monitor (LPRM) removal Weakness - we created a situation for potential administrative overexposure.
Root Cause - Lack of knowledge / training on job specifics.
Immediate Corrective Action - stopped work, investigated, identified weakness and communicated results to personnel.
Long Term Corrective Action - Train RPTs and fuel handlers on job' specifics.
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i RP PROGRAM ENIIANCEMENTS/ OVERVIEW Leonant Oshier
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l Program basically sound. The majority of work proceeds without incident.
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l Past correction actions have been effective and continue to be effective.
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Quiet turnover hours.
New RWP Implemented j
l Hold points in Mechanical Maintenance Procedures.
In our omgoing effort to continuously improve our program. The Station has initiated j
enhancements prior to these events happening.
Source Term Reduction Project Manager l
RP Supervisor to Mechanical Maintenance Staff
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Clean floodup system.
l Exploring non-CECO stations for program improvements.
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RESPONSE TO PROGRAMMATIC CONCERNS Joe Schmeltz
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We agree that the program has the weaknesses identified by the Commission. We j
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recognized these weaknesses before the event and initiated several actions to address them.
We established enhanced expectations on pre-job briefing criteria which required additional management involvement.
An expectation was established that instituted a 20% requirement for management time spent out in the plant to perform overviews of plant activities and to increase opportumties
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to communicate with workers in their environment.
Prior to the outage we held an "All Station Personnel" meeting focusing on critical areas within the organization such as radiation control practices, housekeeping, and procedure l
adherence.
l Selected RP Management personnel were identified to work in various areas of the j
maintenance and contractor support organizations providing ALARA oversight.
l Specifically for this outage, we distributed an outage booklet entitled "An Outage of l
Teamwork by the #1 Station" which contained information on the outage. This j
information encompassed all relevant outage data for handy reference.
In addition we required all working groups to establish Monday and Friday interdepartment communication meetings. At these meetings we discuss weekly activities and track the perf,.mance, good and bad, in order to keep all informed and knowledgeable.
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LASALLE CULTURE ISSUES Joe Schmeltz We believe there are some issues with radiation worker practices and radiation worker culture that we have to better understand if we are to continue to improve.
To establish a better understanding, we administered a culture survey to all the working departments and found that over 98% of those polled viewed themselves, or themselves and the RPT responsible for their radiological safety.
Additionally, the survey identified several issues within the RP department:
Technicians need to do more decision making on jobs with support from management.
Need to develop a better work together attitude / team build.
Helpful if technicians could be assigned to jobs from start to finish.
Need to improve communications with workers in plant, with other departments, interface with other departments more.
Continue to review radiation rules to see if there are better ways to do business.
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Improve trust between union and management.
Management should enforce RP expectations and make it a priority so workers believe it's important.
In addition to the survey we conducted a Radiological Performance Culture Study. This study was conducted by two offsite Health Physicists and consists of three phases.
Phase 1 Review station findings and implementation of Corrective Actions.
Review Towers Perrin survey identifying barriers.
Survey Radiation Protection users for benchmarking.
Phase 2: Identify the areas of concern and provide recommendations.
Phase 3: Assist in Corrective Action implementation and follow-up.
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ACTIONS TO ADDRESS PROGRAMMATIC AND CULTURE ISSUEF Joe Schmeltz Management expectations on Radiological Performance have been discussed with station personnel during a special stand down session.
Stand down focused on only Radiation Worker practices.
Obtained significant information and concerns from workers.
A multi-disciplinary team is being established to address the input.
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Ongoing one-on-one coaching between RP manager and RP union personnel. Small work group sessions between RP manager and management personnel.
An organizational change was made, the RP Manager reports to the Station Manager.
Establishing a teambuilding sessions program.
This is the first time that an Organizational Effectiveness facilitator will be used to develop a program. This should provide greater opportunity for success.
Evaluating RPT assigned total job coverage.
Establishing a small management / bargaining unit RP group to address barriers that are inhibiting this concept. Such barriers include dose leveling, job duration, etc.
Radiation Protection personnel will begin attending communication sessions with various departments.
RPTs will attend weekly communication meetings of other departments such as done at Byron. Based on Byron initiatives, LaSalle will be able to maximize benefits of this effort.
RP attendance will help develop a better understanding of roles and responsibilities et each other.
Site Vice President (SVP) has instituted a 20% of the time in-plant requirement for upper level managers.
All upper level managers are interacting with workers in the field.
Discussions are held every Monday with the SVP, reviewing the individual's field visit comments.
This applies during outage and non-outage periods.
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Corrective Action Manager (CAM) Program Implementation.
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A senior station manager (Site Engineering and Construction Manager) has been designated as the lead.
Reassigned all his normal responsibilities to others.
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Foc is will be on monitoring and correcting:
Radiation worker practices.
Housekeeping issues.
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Procedure compliance.
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Material condition.
Additional staff are being made available and assigned to assist the CAM in these field reviews.
Staff will review worker identified issues with the Corrective Action Manager for
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resolution.
The program will remain in effect through L2R05.
Develop actions from the Radiological Performance Culture Study.
A Radiation Worker impact Team will be established to address recommendations and
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an implementation plan.
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SQV Oversight during L2R05.
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t A two member RP Team in reviewing package preparation for high dose / contamination jobs.
Establishing a Business Development Team similar to Quad Cities.
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CLOSING Warun Murphy
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Event shows that we need to continue to enhance the RP program aui
.e have initiated the actions discussed today.
Personally committed to more aggressive action.
We are actively soliciting worker fe.edback and conducting a culture review.
Additionally, we are participating in the Corporate RP Effectiveness review.
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I am convinced that these actions will result in a superior program.
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ATTACIIMENT A
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DETAILED CIIRONOLOGY OF TIIE REFUEL FLOOR CONTAMINATION EVENT
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NARRATIVE:
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On midnight shift of 09/07/93, Mechanical Maintenance (MM) personnel were involved in detensioning the Reactor Vessel Head. This was a carry over from the previous shift and
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it was completed at 06:12.
Air sample results taken in the Reactor Cavity during the detensioning process were <
0.25 MPC.
During the midnight shift, a Fuel Handling Supervisor toured the Refuel Floor and specifically noted that, in his opinion all Refuel Floor hatches and penetrations were adequately sealed.
At the beginning of day shift, a pre-job briefing was held in the Mechanical Maintenance Shop to discuss the planned Reactor disassembly activities for the shift. The briefing consisted of viewing a video tape as the MM Supervisor narrated a discussion of stud removal process, nut removal and storage, bellows insulation removal by contract insulators, Reactor Vessel Head removal and initial cavity floodup. After these discussions the Radiation Protection Technicians (RPT) described the radiological conditions and clothing requirements.
A discussion was held between one of the MM Supervisors (MM #1) and the Lead RPT (RPT #1) concerning the use of air-powered tools in the Reactor Cavity. The discussion centered around the use of an air impact wrench and two smaller air ratchets.
Investigation has revealed that RPT #1 does not recall discussing the use of the larger air impact wrench.
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Workers then proceeded to the Refuel Floor.
0800 Workers began arriving on the Refuel Floor. The crew entering the Reactor Cavity was wearing two full sets of protective clothing, a face shield and the required dosimetry.
Mla After gathering their tools, the first crew (2 mechanics and the MM Supervisor (MM #1))
entered the Reactor Cavity. The first crew began to break the vessel studs free, after coating each with oil (WD-40) to control contamination utilizing an air powered impact wrench (13 studs for NDE testing and the normal 6 removed for the " cattle chute"). The impact wrench was supplied with air via a 3/4" red hose, and exhausted into the waist of the mechanic.
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0B19 The second crew (2 mechanics), entered the cavity to begin extracting the loosened studs utilizing a smaller air driven ratchet. The air supply for this wrench was via a 3/4" air line reduced to a 3/8" extension, the air exhausted out the end of the wrench's handle to the side of the mechanic.
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The remaining workers (3 mechanics) accessed the cavity to remove the nuts from the
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remaining studs utilizing a smaller air-driven ratchet. The air supply for this wrench was via a 3/4" air line reduced to a 3/8" extension. The air exhausted out the end of the wrench's handle to the side of the mechanic. The removed nuts were also being loaded into boxes for transport and storage.
This came to a total of 8 personnel in the cavity and 3 air supplied tools. There were
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2 RPT's (RPT#2 and RPT#3) present on the Refuel Floor at this time, the Refuel Floor Coordinator, a second MM Supervisor (MM #2), a signalman, a crane operator and a contractor working on the ROV submarine. Other personnel were entering and exiting the floor at various times.
There was no RPT present in the Reactor Cavity, an air sample was not pulled in the cavity at this time. 3 CAMS were in use on the 843' elevation, none near the cavity and no air sample was being taken near the cavity.
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Log entry - Smears taken of the 843' elevation, Refuel Floor general work area were 10K to 50K dpm. RPT#2 then contacted the fuel handlers to clean the surrounding floor areas.
0900 The Unit's Operating Shift secured the Reactor Building Ventilation (VR) for the performance of damper tests (LaSalle Operating Surveillance LOS-CS-Ql) as scheduled through Work Planning.
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RPT#1 entered the Refuel Floor to relieve, RPT#3 for a break. RPT#1 then began to
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perform a source check of the Mini-Edgar Portable Air Sampler. He could not get the air sampler to source check so he proceeded to walk back to his desk, passing the CAM at the north end of the Refuel Floor. The alarm light was lit. He attempted unsuccessfully to reset the alarm and then examined the chart recorder. He noticed a sharp increase on the chart and then went to examine the second CAM located near the RPT desk at approximately the 18 line. He observed a trend on this machine though it had not yet
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alarmed. RPT#1 decided to perform a contamination check of the Refuel Floor, but before he had started, he received a phone call from RPT#3 informing him that RPT#3 had facial contamination. RPT#1 then immediately notified the Maintenance Supervisor (MM #2) on the floor to bring the workers out of the cavity. This was immediately relayed to the workers via radio communications.
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Later inspections of the CAM charts has shown that the alarm for the unit at the north end must have just come in. The CAMS were all set at various alarm settings, inconsistent with their locations.
The CAM chart recordings indicate that the securing of Reactor Building Ventilation (VR)
resulted in n-decrease in the rate of change of contamination levels on the Refuel Floor.
0927-0940 The maintenance workers exited the cavity and the Refuel Floor.
023R RPT#1 started an air sample at the cavity handrail on 843'. (The air' sample field checked at 500k dpm.)
0940 The Refuel Floor Coordinator contacted the Operating Shift Engineer (SE) and informed him of the condition of the floor. They decided to restart the Unit 2 (U-2) VR because they believed that the lack of VR had caused the problem. (When VR was restarted, the contamination was pulled throughout the Reactor Building via pathways at the U-2 Elevator Penthouse and the U-2 equipment floor plugs).
Later inspections of the equipment floor plugs revealed that the rubber strips used as seals had shifted. allowing a ventilation path to the rest of the Reactor Building.
The following floors of the lower elevations were contaminated: 820',10K near the Equipment Hatch; 786',6K near the hatch; 761', < 1K near the hatch; 710' was not affected near the hatch.
The floors of the lower elevations near the elevator shaft were also contaminated due to
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ventilation flow paths in the Elevator Penthouse and the elevator movement: 832' through c
740'showed 2K at the entrance to the U-2 elevator. The inside of the elevator was contaminated 8K on the wall, and the Elevator Penthouse was contaminated up to 20K.
710' elevation and below were not affected by the event.
1015 The SE was informed of the spread of contamination and a PA announcement was made
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to secure access to the U-l and U-2 Reactor Buildings. Follow-up surveys and recovery
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commenced immediately.
i An investigation was started immediately following the initial decon of the individuals.
22 personnel were contaminated as a result of this one event. 3 were working elsewhere in the Reactor Building, receiving contamination on their shoes. I was a Security Guard at the Refuel Floor access on 843'. The remaining 18 were on the Refuel Floor. 17 l
workers showed positive whole body counts.
i A team was established to start the investigation. The initial intent was to determine the root cause of the spread of the contamination and to decide whether to allow work to
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continue or not. (The preliminary determination based on Root Cause Analysis techniques, was that the VR System shutdown and startup did not cause the event but it spread the contamination further and faster. Actions within the cavity had caused the contamination spread to 843').
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After consideration of what evolutions were still to be completed, work resumed with the
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following restrictions:
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l. Respirators were to be worn for the remainder of the work in the cavity.
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2. An RPT would perform a complete survey of the cavity, studs, and vessel head prior to any workers entering the cavity. The survey was also to include the tooling exhaust ports and hoses.
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3. A HEPA System would be set up and used at each stud as it was being extracted.
4. An RPT would be in attendance and an air sample taken during the removal of the remaining studs.
5. Air samples would also be taken on the upper,843' elevation.
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6. The equipment hatch was to be inspected to ensure it was sealed properly and taped.
7. All workers on the floor were to take a respirator up with them.
Overall, LaSalle has an acceptable ALARA/ pre-job review process. In this specific job, the process implementation began early in the planning stage for the outage, L2R05. A specific RP Supervisor was in charge of planning and administration. The plan included the routine previous RP methodology used for vessel work, including Lessons Learned, as well as an innovative approach to empower more authority and control to the RPTs assigned RFF coverage. Prior to completion of the plan, the plan Supervisor became unavailable due to health issues. Previous outage successes, including Lessons Learned, a developing trend of successful RP preparation reflected by decreasing PCEs and dose, and a (perceived) vessel disassembly RP plan ready, all led to the expectation of a successful job. In reality the plan was not completed and the appropriate RP coverage was lackmg.
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