ML18065A896

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LER 96-011-00:on 960730,CR Continuous Air Monitor Alarm Setpoint Improperly Established.Caused by Failure to Utilize Mod Process in 1988 Leading to Failure to Properly Select & Calibrate Instruments
ML18065A896
Person / Time
Site: Palisades Entergy icon.png
Issue date: 08/29/1996
From: Mathews C
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18065A895 List:
References
LER-96-011, LER-96-11, NUDOCS 9609100228
Download: ML18065A896 (5)
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Text

NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (4195) EXPIRES 4130/98 ES'llMATED IUIOEN PER RESPONSE TO COMPLY wmt THIS llANDATORY INFORMATION COUEC'T10N REQUEST: 50.0 HRS. REPORTED LESSONS LEARHED ARE INCORPORATED INTO THE LICENSING PROCESS NW FED BACK TO INDUSTRY. FORWARD COMMENTS LICENSEE EVENT REPORT (LER) REGAHDING llURDEN ESTIMATE TO THE INFORMATION NW RECORDS MANAGEMENT BRAHCti (T~ F33), U.S. tu::LEAR REGULATORY COMMISSION, WASHINGTON, DC 2055s.

0001, NW TO THE PAPERWORK REDUCTION PROJECT (315G-010<, OFFICE OF (See reverse for required number of digits/characters for each block) MANAGEMENT NW BUDGET, WASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NUMBER (2)

PALISADES NUCLEAR PLANT 05000255 R)ofS II TITLE(4) LICENSEE EVENT REPORT 96-011 - CONTROL ROOM CONTINUOUS AIR MONITOR ALARM SETPOINT IMPROPERLY ESTABLISHED EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I SEQUENTIAL NUMBER REVISION NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 FACILITY NAME DOCKET NUMBER 07 30 96 96 - 011 - 00 08 29 96 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check one or more) (11)

MODE (9) N 20.2201(b) 20.2203(a)(2)(v) 50. 73(a)(2)(1) 50. 73(a)(2)(iii) 20.2203(a)(1) 20.2203(a)(3)(1) x 50.73(a)(2)(ii) 50.73(a)(2)(x)

I POWER LEVEL (10)

I I99.6 20.2203(a)(2)(1) 20.2203(a)(2)(ii) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(iv) 73.71 OTHER 11'.'l 20.2203(a)(2)(iii) 50.36(c)(1) 50. 73(a)(2)(v) Specify in Abstract below or 20.2203(a)(2)(iV) 50.36(c)(2) 50.73(a)(2)(vii) in NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

Clayton M. Mathews (616) 764-2035 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR I YES If yes COMPLETE EXPECTED COMPLETION DATE x I NO EXPECTED*

SUBMISSION DATE 115)

ABSTRACT (limit to 1400 spaces, i.e .. approximately 15 single-spaced typewrit1en lines) (16)

At 1347 hours0.0156 days <br />0.374 hours <br />0.00223 weeks <br />5.125335e-4 months <br /> on July 30, 1996, with the plant at 99.6% power, the Control Room Viewing Gallery Continuous Air Monitor (CAM), Eberline Model AMS-3, was declared inoperable due to an incorrect alarm setpoint. The setpoint problem was discovered while preparing an engineering analysis on Control Room habitability. The setpoint was based on- particulate activity rather than noble gas activity as required. This monitor is utilized to warn Control Room personnel of airborne radioactivity that is entering the Control Room Heating, Ventilation, and Air Conditioning (CR-HVAC) system for events that do not generate a signal which automatically switches the CR-HVAC to the emergency mode. Without a method for detecting radionuclide ingress into the Control Room following these type of events, manual switchover to the emergency mode of CR-HVAC c9uld be d~layed. With. a switching delay, predicted operator doses may exceed General Design -

Criteria 19 limits. CR-HVAC remained operable in its emergency mode (charcoal filtration in service) until an adequate instrument for noble gas alarm detection was provided.

At 1831 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.966955e-4 months <br /> on July 30, 1996, the AMS-3 CAM was replaced by an Eberline Model AMS-4 CAM, which was calibrated for noble gas detection capabilities.

9609100228 960829 PDR ADOCK 05000255 S Pr;',~,.

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I

FACILITY NAME 11 l DOCKETl2l LER NUMBER 61 PAGE 131 YEAR SEQUENTIAL REVISION NUMBER NUMBER PALISADES NUCLEAR PLANT 05000255 2 OF 5 96 011 00 TEXT {If more space is required, use additional copies of NRC Form 366A) (17)

EVENT DESCRIPTION At 1347 hours0.0156 days <br />0.374 hours <br />0.00223 weeks <br />5.125335e-4 months <br /> on July 30, 1996, with the plant at 99.6% power, the Control Room Viewing Gallery Continuous Air Monitor (CAM), Eberline Model AMS-3, was declared inoperable due to an incorrect alarm setpoint. The setpoint problem was discovered while preparing an engineering analysis on Control Room habitability. The setpoint was based _on particulate activity rather than noble gas activity as required. This monitor was utilized to warn Control Room personnel of airborne radioactivity that is entering the Control Room Heating, Ventilation, and Air Conditioning (CR-HVAC) system for events that do not generate a signal which automatically switches the CR-HVAC to the emergency mode. Without a method for detecting radionuclide ingress into the Control Room following these type of events, manual switchover to the emergency mode of CR-

CR-HVAC remained operable in its emergency mode (charcoal filtration in service) until an adequate instrument for noble gas alarm detection was provided.

At 1831 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.966955e-4 months <br /> on July 30, 1996, the AMS-3 was replaced by an Eberline Model AMS-4 CAM, which was calibrated for noble gas detection capabilities.

The following causes and series of events occurred since 1988 and allowed this CAM alarm setpoint condition to remain undiscovered:

1. A failure to utilize the modification process occurred when the AMS-3 was first placed in service in 1988. The AMS-3 was installed as part of the Health Physics Portable Instrument (HPPI) program without proper modification documentation *approval. . *
2. There was a failure to properly calibrate the instrument (AMS-3) for the application (noble gas monitor versus particulate monitor). The calculation for the setpoint contained errors that led to the improper alarm setpoint and the incorrect application of the AMS-3.
3.
  • A questioning attitude was lacking. A review of reference documents indicated that one *
  • possible reason this issue was not identified was the assumption that the CAM was designed for the application. There is no documentation that individuals with technical knowledge of the instrument's capabilities and limitations were consulted until 1996. All evaluations previous to 1996 assumed the instrument was calibrated properly *and the Health Physics Instrument group never questioned whether the instrument was being used in a manner outside of its capabilities.

II============================='=============================================::dJ'

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I

FACILITY NAME 11 \ DOCKETl2\ LER NUMBER 16\ PAGE f3\

YEAR SEQUENTIAL REVISION NUMBER NUMBER 3 OF 5 PALISADES NUCLEAR PLANT 05000255 96 011 00 TEXT (If more space is required, use additional° copies of NRC Form 366A) (17)

4. Clear ownership of the issue was lacking. The AMS-3 was installed as part of the Health Physics Portable Instrument (HPPI) program without proper modification documentation approval and the Health Physics Instrument group never questioned its application. The setpoint calculation and the total system operation/coordination responsibilities for this CAM were divided between Health Physics and Reactor Engineering.
5. Adequate commitment management was lacking. In November 1988, a Continuous Air Monitor (CAM) was installed. This information was reported to the NRC in LER-88-013-01.

We also committed to evaluate the feasibility of installing permanent radiation monitors for an automatic switch over of the CR-HVAC. The feasibility review was completed and it was determined that it was not feasible to perform the modifications. This was reported to the NRC in LER-88-013-02, dated March 1989. We also stated that we would perform additional evaluations to determine if other cost beneficial engineering options were available. In * *:

August 1989, we provided the final results of the engineering evaluations in LER-88-013-03.

We stated that we would provide automatic switch over of the CR-HVAC system to the emergency mode using the main steam line gamma monitors and the radioactive gaseous effluent monitoring system as initiators for the switch. The commitment to complete this modification was closed out to a follow-up corrective action and the commitment tracking system showed the item as closed. The project to make the modification was later canceled without recognition that it was tied to an NRC commitment. This missed commitment was identified in 1994. In July of 1994, we provided the NRC with a history of the issue and reported that the modification had not been perfa-rmed. **We committed' to reevaluate the .!

issue and report the results back to the NRC when that evaluation was complete.

ROOT CAUSE There was no single root cause but the following factors allowed this condition to remain undiscovered:

1. A failure to utilize the modification process in 1988 led to the failure to properly select and calibrate an instrument for the application.
2. Ownership of the issue was not clearly assigned and the personnel who were involved failed to display a questioning attitude.
3. Adequate commitment management was lacking.

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I

~4CILITY NAME <1 l DOCKETl2l LER NUMBER 61 PAGE l3\

YEAR SEQUENTIAL REVISION NUMBER NUMBER 4 OF 5 PALISADES NUCLEAR PLANT 05000255 96 011 00 rEXT (If more space is required, use additional copies of NRC Form 366A) (17)

SAFETY IMPLICATIONS This CAM was placed in service to alert Control Room personnel of radionuclide ingress following only those design basis events which do not automatically initiate a switch of the CR-HVAC system to the emergency mode. These events do not include Loss of Coolant Accidents or Main Steam Line Breaks inside containment, because the degraded containment environment automatically causes the CR-HVAC shift to the emergency mode. The limiting events, for which this manual switchover is required, are events with radiological releases outside containment. With CR-HVAC in the normal operating mode, it is possible for radionuclides to migrate through the normal HVAC fresh air intakes and enter the Control Room ventilation envelope. With CR-HVAC in the emergency mode, the normal fr~sh air intakes are closed, and air makeup is provided through charcoal filters, preventing radionuclide ingress. Delaying a switch to the emergency mode can increase operator doses by permitting more radionuclides to enter the Control Room.

In accordance with Standard Review Plan (SRP) Section 6.4, cumulative operator doses after relevant design basis events are predicted for 30 days after the event. Conservative assumptions .

are made about stay times, breathing rates, etc. in calculating these doses. Most importantly, the SRP predictions assume that the same operators are present over the entire 30 days. No credit is allowed for personnel dose monitoring and resulting reassignment of control room personnel which would occur if dose limits were approached.

  • *Accordingly,- the safety implications of the inadequate CAM setpoint were low because th*e CAM is only needed for releases outside of containment, and the fact that personnel dose monitoring would occur and result in active management of the time any operator would be required to spend within the control room envelope.

CORRECTIVE ACTION CORRECTIVE ACTION TAKEN AND RESULTS ACHIEVED

1. The AMS-3 was removed*from the Control Room. An Eberline Model AMS-4 CAM was calibrated and installed inthe control room viewing gallery with an alarm setpoint which

.correlates to 1E-5µCi/ml Xe-133. The AMS-4 has a sample head designed for noble gas* - * -

detection and has intrinsic software capable of constant monitoring for the isotope of concern. Control Room personnel have been informed of the change and appropriate operator aids haye been modified along with Standing Order 62. In addition, a review was conducted of other Health Physics Portable Instruments to validate that there were no other instruments placed in service in a condition outside of their capabilities. The Control Room AMS-3 was the only instrument of this type.

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 11 l DOCKET12l 05000255 YEAR ILER NUMBER 6\

SEQUENTIAL NUMBER I REVISION NUMBER PAGE13l 5 OF 5 PALISADES NUCLEAR PLANT 96 011 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

2. A modification to permanently install two Eberline AMS-4 CAMs with noble gas detection heads in the CR-HVAC Mechanical Equipment Room is in progress with completion expected in November 1996. Alarm annunciation will be provided in the Control Room.

Automatic CR-HVAC emergency mode switch-over is not planned to be implemented with this modification. The automatic switch:--over feature is still under evaluation.

3. Ownership of Control Room Habitability Analyses and associated modifications has been assigned to the Nuclear Engineering Section of the System Engineering Department.

CORRECTIVE ACTION TO PREVENT RECURRENCE

1. Evaluate current methods of setting various Health Physics Portable Instrument (HPPI) equipment setpoints to determine if. any or all instrument setpoints should be re-calculated and/or re-justified.
2. Review the controls that govern the Temporary Modification Program and assess whether this event would have been properly controlled had it taken place with today's standards.
3. Evaluate whether automatic switchover of the Control Room Heating, Ventilation, and Air Conditioning (CR-HVAC) to emergency mode is necessary and justifiable for events that cause the AMS-4 to alarm. *
4. Verify that commitment management procedures and practices are in place to assure that actions are properly addressed prior to closing a commitment.

PREVIOUS SIMILAR EVENTS LER 88-013 - Inoperable Control Room Ventilation System

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