IR 05000315/1992023
| ML17331A013 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 02/05/1993 |
| From: | Jorgensen B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17331A012 | List: |
| References | |
| 50-315-92-23, 50-316-92-23, NUDOCS 9302160022 | |
| Download: ML17331A013 (10) | |
Text
U.
S.
NUCLEAR REGULATORY COMMISSION
REGION III
Report Nos.
50-315/92023(DRP);
50-316/92023(DRP)
Docket Nos.
50-315; 50-316 License Nos.
Indiana Hichigan Power Company 1 Riverside Plaza Columbus, OH 43216 Facility Name:
Donald C.
Cook Nuclear Power Plant, Units 1 and
Inspection At:
Donald C.
Cook Site, Bridgman, HI Inspection Conducted:
December 3,
1992, through January 19, 1993 Inspectors:
J.
A. Isom D. J. Hartland Approved By:
B. L. Jorgensd~,
Chief Reactor Projects Section 2A ate Ins ection Summar
- Inspection from December 3, 1992, through January 19, 1993.
(Report Nos.
50-315/92023(DRP);
50-316/92023(DRP))
Areas Ins ected:
Routine unannounced inspection by the resident inspectors of: plant operations; maintenance and surveillance; radiological controls; and reportable events.
Results:
No violations or deviations were identified.
The inspection disclosed a strength in the licensee's immediate corrective actions in response to problems with the Individual Rod Position Indication System experienced during the inspection period.
The inspection disclosed weaknesses in the licensee's control of high radiation areas relating to initial residual heat removal (RHR) system operation during refueling outages.
9302160022 930205 PDR ADOCK 050003l5
DETAILS Persons Contacted
- A. A.
- K. R.
L. S.
- J.
E.
B. A.
T.
P.
P.
F.
D.
C.
L. J.
T.
K.
- J. R.
- P.
G.
+J.
S.
L.
M.
G. A.
- J. T.
M. L.
Blind, Plant Manager Baker, Assistant Plant Manager-Production Gibson, Assistant Plant Manager-Projects Rutkowski, Assistant Plant Manager-Technical Support Svensson, Executive Staff Assistant Beilman, Maintenance Superintendent Carteaux, Training Superintendent Loope, Radiation Protection Superintendent Matthias, Administrative Superintendent Postlewait, Design Changes Superintendent Sampson, Operations Superintendent Schoepf, 'Project Engineering Superintendent Wiebe, Safety h Assessment Superintendent Vanginhoven, Site Design Superintendent Weber, Plant Engineering Superintendent Wojcik,Chemistry Superintendent Horvath, guality Assurance Supervisor The inspector also contacted a number of other licensee and contract employees and informally interviewed operations, maintenance, and technical personnel.
- Denotes some of the personnel attending the Management Interview on January 26, 1993.
Plant 0 erations 71707 71710 42700 The inspector observed routine facility operating activities as conducted in the plant and from the main control rooms.
The inspector monitored the performance of licensed Reactor Operators and Senior Reactor Operators, of Shift Technical Advisors, and of Auxiliary Equipment Operators including procedure use and adherence, records and logs, communications, and the degree of professionalism of control room activities.
The inspector reviewed the licensee's evaluation of corrective action and response to off-normal conditions.
This included compliance with any reporting requirements.
The inspector noted the following with regard to the operation of Units 1 and 2 during this reporting period:
a.
Unit 1 status:
The licensee operated the unit at full power throughout the inspection period, with no significant operational problems note b.
Unit 2 status:
At the beginning of the inspection period, the licensee had the unit in Mode 1, at approximately 8 percent power, and was troubleshooting continued turbine generator vibration problems.
The licensee put the unit in Mode 2 on December ll, 1992, for generator bearing clearance adjustments and generator hydrogen, seal modifications.
At 3 p.m.,
on December 19, 1992, the licensee paralleled the unit to the grid and brought it to 100 percent power on December 26, 1992.
The licensee operated the unit at full power for the remainder of the period.
No violations, deviations, unresolved or inspector followup items were identified.
Maintenance Surveillance 62703 61726 42700
The focus of the inspection was to assure the maintenance activities were conducted in accordance with approved procedures, regulatory guides and industry codes or standards, and in conformance with Technical Specifications (TS).
The following items were considered during this review: the Limiting Conditions for Operation were met while components or systems were removed from service; approvals were obtained prior to initiating the work; activities were accomplished using approved procedures; and post maintenance testing was performed as applicable.
The activities related to the following problem were inspected:
Individual Control Rod Position Indication IRPI S stem Problems The inspector reviewed licensee actions in response to IRPI problems that occurred during the inspection period.
The inspector determined that immediate actions taken by the licensee wer e timel a
ro riate.
The licensee has yet to take preventive actions in response to deficiencies associated with the system which have caused problems over the last several years.
However, licensee management informed the inspector that the licensee intends to address the issue durin the 1995 96 time frame, as documented in their strategic plan.
The IRPI system consisted mainly of the primary sensors and the signal conditioning modules.
The primary sensors were linear transformer type detectors mounted on the outside of the control rod drive housings and consisted of alternately stacked primary and secondary windings.
The vertical position of the top of the control rod drive shaft within each detector determined the amount of coupling between the primary and secondary windings.
The output voltage from the secondary windings was an AC signal whose amplitude was proportional to the actual rod position.
The detector output signal voltage was transmitted to the signal conditioning module, which converted the signal to DC for use by the control board indicator and the plant compute On December 25, 1992, the licensee entered TS 3.0.3 after it was noted th'at two Unit 2 bank D control rod IRPIs in the same group, H-12 and N-8, indicated greater than 12 steps from the demand position indication.
TS 3. 1.3.2 allowed for a maximum of one IRPI channel per group to be inoperable.
With one IRPI inoperable, the TS required the position of the rod be indirectly determined by the movable incore detectors at learnt once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
The two IRPIs drifted out of alignment after the bank was driven in about 10 steps over an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> time period to control reactor core axial flux difference (AFD).
Readings taken by the 18C technician at the output of the secondary windings also indicated that the rods were greater than 12 steps from demand.
As a result, the licensee entered TS 3.0.3 at 2:28 p.m.
As immediate corrective action, the unit operators pulled the bank D rods out about 4 steps and returned the rod H-12 indication to within TS requirements.
The licensee exited TS 3.0.3 at 2:58 p.m.
The licensee attributed the problem to the inherent sensitivity of the IRPIs to temperature changes, caused by the rod movement, at the transformer-type detectors on the control rod drive housings.
The licensee started an additional control rod drive mechanism fan to stabilize the temperature.
The licensee performed flux maps to verify the position of H-8, as required by TS, until December 26, 1992, when the IRPI drifted back to within TS requirements.
The licensee entered the TS 3.1.3.2 action statement and resumed flux mapping on January 6,
1993, when the IRPI for rod M-8 drifted out again.
Flux mapping continued until January 12, 1992, when the IRPI drifted back after ILC replaced the signal conditioning module during troubleshooting.
The inspector observed the maintenance activity and reviewed the work package and did not identify any concerns regarding the activity."
Additionally, the licensee had problems with other IRPIs during the inspection period.
The IRPI for shutdown rod B-8 on Unit 1 was declared inoperable for a short period of time on January 18, 1993.
The inspector also noted that the IRPI for rod K-2 in control bank B on Unit 2 had provided an erratic indication during the inspection period which, although staying within 12 steps of demand, caused the rod sequence violation annunciator alarms.
The inspector spoke with the System Engineer and an I&C engineer about what preventive action was being taken to correct the ongoing problems with the IRPIs.
The inspector was told that two viable options had been evaluated in the past.
The first option was to replace the system with a more reliable digital system.
The other option was to request a
change to the TS to allow for (greater than)
12 steps deviation from deman The inspector noted that the licensee has not experienced a plant transient due to problems with the IRPI system in the past.
Although not a regulatory issue, the problems are a distraction to unit operators.
The licensee intends to address the issue in the 1995/96 time frame, as documented in their strategic plan.
No violations, deviations, unresolved or inspector followup items wqre identified.
Radiolo ical Controls 71707 During routine tours of radiologically controlled plant facilities or areas, the inspector observed occupational radiation safety practices by the radiation protection staff and other workers.
The inspector reviewed the following:
RHR S stem Surve Review The inspector identified a concern in NRC Inspection Report (IR)
No. 92018 relating to the adequacy of formal mechanisms to ensure that non-routine surveys are performed on a timely basis in response to changes in plant status.
As follow-up to this issue, the inspector reviewed survey data of initial RHR system operation during refueling outages dating back to 1990.
The ins ector identified two exam les of hi h radiation areas HRAs that ossibl were not ro erl controlled.
The licensee's control of areas in which radiation levels chan e because of non-routine lant evolutions was determined to be a weakness.
The licensee's definition of an HRA, as documented in PHI-6010,
"Radiation Protection Plan,"
Rev. 8, dated April 30, 1992, was
"any area, accessible to personnel, in which there exists radiation at such levels that a major portion of the body could receive in any one hour a
dose in excess of 100 millirem."
The licensee used a distance of 30 cm from a source as the criterium for determining if an area is accessible to personnel.
The first example was in the Unit 1 West residual heat removal (RHR)
Pump room during the 1992 outage.
The area was not posted as an HRA despite a documented survey, dated June 25, 1992, which indicated a
general area dose rate of 100 mrem/hr.
In response to this concern, the licensee initiated Problem Report (PR)
No. 92-2028 to document the deficiency.
Their investigation of this PR revealed that the radiation protection technician (RPT)
who took the survey considered this area, located on the pump discharge piping elbow, as not readily accessible and, therefore, not considered general area for whole body exposure.
The RPT did not document this assessment on the survey sheet.
Based on the survey data available, therefore, the licensee concluded that the area should have been posted as an HR The inspector noted, based on review of documented surveys taken in the pump room during that time period, that radiation levels were trending upward quickly.
After initiation of RHR operation at 10:49 a.m.
on June 25, 1992, general area radiation levels on the elbow rose from 30 mr/hr at 1:00 p.m. that day to 100 mr/hr at 1: 15 a.m.
on June 26.
A similar condition existed in the Unit 1 East RHR Pump Room, where levels rose from 50 mr/hr to 80 mr/hr during this time period.
Despite the.
upward trend, the licensee did not perform another documented survey in either pump room until 3: 19 a.m.
on June 27, shortly after an RCS chemical flush was initiated.
At that time, general area radiation levels were measured as high as 300 mr/hr in the West RHR Pump Room and 225 mr/hr in East RHR Pump Room.
The room was then posted as an HRA.
However, the inspector concluded that, based on the 100 mr/hr level discovered on June 25 and the upward trending of the levels at that time, it would have been prudent to post the areas as an HRA or maintain the frequency of the surveys performed.
The inspector identified a similar situation during review of surveys taken during the Unit
1990 refueling outage.
During this outage, the licensee placed RHR in service on October 21, 1990.
The only documented survey in the RHR pump rooms during this time period was not taken until October 24, 1992.
At that time, general area levels reached 250 mr/hr in the East RHR Pump Room at which time the room was posted as an HRA.
The potential for personnel overexposure because of these areas not being properly controlled was minimal because work in the RHR rooms would have required Radiation Protection support.
Also, the licensee did not have any documented overexposures during this time period.
As corrective action, documented in the PR investigation, the licensee will change applicable operations procedures to notify the RP prior to initial RHR use during an outage so that rooms can be posted.
The licensee committed to complete the procedure changes by June 30, 1993.
The licensee informed the inspector that there were no other areas in the plant where the potential for uncontrolled HRAs existed due to non-routine plant evaluations.
The inspector has no further concerns regarding this issue.
No violations, deviations, unresolved or inspector followup items were identified.
Re ortable Events 92700 92720 The inspector reviewed the following Licensee Event Reports (LERs)
by means of direct observation, discussions with licensee personnel, and review of records.
The review addressed compliance to reporting requirements and, as applicable, that immediate corrective action and appropriate action to prevent recurrence had been accomplishe (Closed)
LER 315/92004-LL:
Missed Surveillance on Boric Acid Flow Path Due to Personnel Error Durin Procedure Review Process This LER is being closed based on adequate licensee root cause analysis and corrective action.
On April 24, 1992, the licensee entered TS 3.0.3 for a short period of time after it discovered that a TS surveillance had not been performed within the required grace period.
The surveillance that was not performed was to satisfy the requirement for TS 4. 1.2.2.a. I, which specifies that the boration flow paths from the refueling water storage tank and the basic acid storage tank be demonstrated operable at least once per seven days.
This was done by cycling each testable power-operated or automatic valve in the flow path through at least one complete cycle of full travel.
The licensee had not performed the surveillance since April 13, 1992.
The licensee determined that the cause of the event was personnel error.
The Unit Supervisor had erroneously documented that the surveillance was completed in the master surveillance schedule.
During subsequent review of completed surveillance paperwork, Operations engineering noted that the surveillance was not performed; however, it was assumed that the shift management had rescheduled the surveillance, and the issue was not pursued.
As immediate corrective action, the licensee successfully completed the surveillance and exited TS 3.0.3.
In addition, Operations management reviewed the event with the personnel involved.
The inspector noted that this was an isolated event and that the licensee's procedures for ensuring that TS surveillances are completed in a timely manner were adequate.
This LER is closed.
(Closed)
LER 316/92007-LL: Reactor Tri From Turbine Tri Caused b
a Sudden Loss of Main Condenser Vacuum Durin Dia nostic
~Testin This LER is being closed based on satisfactory licensee root cause analysis and corrective action.
On July 2, 1992, the reactor tripped from approximately 8 percent power after the licensee manually tripped the turbine due to loss of condenser vacuum.
At that time, the licensee was adjusting condenser vacuum using a startup air ejector during troubleshooting of main turbine-generator vibrational problems.
As discussed in IR 92014, the inspector noted that the licensee did not have a procedure to control the vacuum reduction evolutio As immediate corrective action, the licensee issued a procedure which was used during subsequent testing that required condenser vacuum to be adjusted.
In addition, the licensee also made enhancements to their normal operating procedures and incorporated lessons learned into an operator training session.
No violations, deviations, unresolved or inspector followup items were identified.
Nana ement Interview The inspectors met with licensee representatives (denoted in Paragraph I) on January 26, 1993, to discuss the scope and findings of the inspection.
In addition, the inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspector during the inspection.
The licensee did not'dentify any such documents or processes as proprietary.