ML20214Q821

Summary of 860528 Meeting W/Util & Bechtel in Bethesda,Md Re Control Room Emergency Ventilation Sys,Per TMI Action Item III.D.3.4 on Control Room Habitability.List of Attendees Encl

ML20214Q821
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	09/19/1986
From:	Chan T Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
TASK-3.D.3.4, TASK-TM TAC-61289, NUDOCS 8609260334
Download: ML20214Q821 (13)

Text

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September 190 1986 Docket No. 50-344 DISTRIBUTION Docket File OGC NRC PDR E. Jordan LICENSEE: Portland General Electric Local PDR B. Grimes PD#3 Rdg. ACRS(10)

FACILITY: Trojan Nuclear Plant S. Varga T. Quay T. Chan J. Hayes

SUBJECT:

MEETING

SUMMARY

REGARDING THE MAY 28, 1986 CONTROL ROOM HABITABILITY MEETING A meeting was held in Bethesda, MD with Portland General Electric Company (PGE) and NRC representative on May 28, 1986 to discuss the Control Room Emergency Ventilation System (CREVS) as it related to Control Room Habitability, TMI Action III.D.3.4. The staff's May 6,1986 request for additional information and PGE's May 19, 1986 response provided the background for discussion. A list of attendees is provided in Enclosure 1.

Discussions rentered around PGE's present and future activities regarding the correction of oeficiencies within the CREVS. Enclosure 2 identifies the major areas of concerns and proposed corrective actions. In cara ction with the corrective actions, the staff requested that PGE provide an update of their CREVS Action Plan (Attachment 2 to their May 19, 1986 respanse) with respect to commitments and schedules, in order for the staff to resolve concerns prior to restart from the 1986 refueling outage.

The NRC staff also requested that PGE provide a revised III.D.3.4 dose calculation utilizing input that was consistent with the implemented and proposed procedural and hardware changes, so that this concern could be resolved prior to restart.

PGE stated that revised Technical Specifications and an evaluation of toxic gas threats on the Control Room would be submitted to the staff by Septcmber 30, 1986. The staff concurred with this schedule.

On June 4, 1986, PGE provided the revised III.D.3.4 dose calculations and update of their CREVS Action Plan. A subsequent telephone conference on June 9,1986 provided additional clarification. These discussions and commitments were formalized in PGE's letter dated June 13, 1986.

DMginal .11gned ty Terence L. Chan, Project Manager Project Directorate #3 Division of PWR Licensing-A

Enclosure:

As stated cc: See next pa'e

1. PD#3 . PW CV an TChan s arca 96 9/}]/86 E

/p/86 8609260334 860719 PDR ADOCK 05000344 P PDR

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,lk Mr. Bart D. Withers Portland General Eletric Company Trojan Nuclear Plant ec: . .

Senior Resident Inspector U.S. Nuclear Regulatory Commission -

Trojan Nuclear Plant Post Office Box 0 Rainier, Oregon 97048 Robert M. Hunt, Chairman Board of County Commissioners Columbia County St. Helens, Oregon 97501 William T. Dixon Oregon Department of Energy Labor and Industries Building Room 111 Salem, Oregon 97310 Regional Administrator, Region V U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 1450 Maria Lane, Suite 210 Walnut Creek, California 94596

o ENCLOSURE 1 LIST OF ATTENDEES -

MAY 28, 1986 CONTROL ROOM HABITABILITY Name Organization T. Quay NRC J. Hayes NRC K. Johnston NRC T. Chan NRC S. Varga NRC R. Jagels Bechtel R. Fosse Bechtel A. Go Bechtel P. Yundt PGE G. Zimmerman PGE D. Kenter PGE 4

ENCLOSURE 2 CONTROL ROOM VENTILATION Major Areas of Concern:

A. Filtered and Unfiltered Inleakage B. Ability to Maintain 1/8" Differential Pressure l

C. Adequate Toxic Gas Protection D. Single Failure Criteria E. Charcoal and Filter Performance F. Control Room Heat Load and Temperature C. Technical 8pecification and Procedure Improvements i

control Room Ventilation Page 1 of 9

A. Filtered and Unfiltered Inleakare Concern / Deficiencies:

1. CB-1B makeup flow was 450 cfm vs. 150 cfm. . .

2. CB-1A cooler duct housing was broken. -

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3. Open cooler drain on CB-1.

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4. Leakage around doors and penetrations. l

5. CB-2 and CB-12 damper leakage.

Conclusions:

The calculated dose that could have been received due to the above deficiencies would have exceeded acceptable levels without using breathing protection or KI tablets.

Corrective Actions:

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1. The outside makeup air flow was adjusted to i 150 cfm. Disassembly and inspection of CB-1A revealed that the makeup flow control damper was rotated 90* from its control handle which accounts for it measuring only 125 cfa. Makeup air will be measured at least every refueling interval.

2. The broken CB-1A cooler duct housing was repaired when discovered.

A full inspection of all CB-1 ducting outside the control room will

be completed at least every refueling interval. ~

3. The open drain line was capped when discovered. The drains were separated and valves installed on each line. Automatic drain traps will be installed after startup.

4. An extensive inspection of all control room boundary penetrations has been made. Several leak paths were identified which have been fixed.

5. Inspection and testing of all control room dampers has been completed. All damper gaskets have been repaired / replaced. The integrity of these dampers will be evaluated at least every refueling outage and a PM program implerented.

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B. Ability to Maintain 1/8" Differential Pressure Concerns / Deficiencies:

1. Control pressure was not maintained > 1/8" AP as compared to all

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surrounding boundaries.

2. Operation of CB-5 on CB-10 effects the ability of CB-1 to' maintain j control room positive pressure.

3. CB-1 system was run with the outside makeup dampers closed, and therefore, it was not possible for it to maintain positive pressure.

! 4. Testing has shown that CB-1 system cannot maintain a positive 1/8" pressure with only 150 cfm makeup air.

Conclusions:

I PCs agrees that measures should be taken to ensure a positive pressure j for all control room boundaries (not just the outside), even though not

required by Technical Specifications. Due to the location of where differential pressure is measured and operation of CB-5 and CB-10 I differential pressure as compared to the outside has not been consistently maintained > 1/8" of water as required by Technical

specifications.

Corrective Actions:

{ 1. Permanent test instruments have been installed to measure

! differential pressure between the control room and surrounding j boundaries. Testing to ensure 1/8" differential pressure to i surrounding boundaries will be conducted at least every refueling I outage.

2. It is intended to implement a design change before startup to automatically trip CB-5 and CB-10 on an automatic start of CB-1. If this design change is not completed before startup, procedures will be implemented to ensure manual tripping until design changes are completed.

3. Procedure changes have been implemented to ensure CB-1 dampers open automatically on safety injection signal.

4. Design changes will be made before startup to increase the distance between the containment and the location of where makeup air is taken from 64 to 128 feet. This design change will allow increasing i the makeup flow from 150 cfm to 450 efm.

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,~ C. Toxic Gas Protection Concern / Deficiencies:

1. Operation of CB-2 and CB-1 during a toxic gas event haf result in l high control room inleakage. ,

! 2. Operation of CB-5 snd CB-10 may result in high control room 1 inleakage.

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3. Operators do not put on masks upon a toxic gas challenge.

4. Should ammonia detector be installed?

Conclusions:

i Operation of CB-2, CB-5 and CB-10 fans during a toxic gas event could have permitted more inleakage than if they were secured.

! Corrective Actions:

1. ONI-54, "High Toxic Cas concentration", has been revised to require securing CB-2 supply fans and starting CB-1 on recirculation only.

ONI-54 will be revised to require stopping CB-2 recirculation fan.

Differential pressure measurement will be verified at least every refueling outage to ensure there is no excessive differential pressure on any control room boundary.

l 2. ONI-54 will be revised to stop CB-5 and CB-10 on high tqxic gas. A l design change will be implemented to automatically stop these fans. ~

j Test will be conducted as noted above.

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! 3. ONI-54 requires operator to don self-contained breathing apparatus, but not wear mask until the alarm is confirmed.

4. Analysis to determine if ammonia detectors should be installed is being performed.

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D. Ability to Meet sinale Failure Criteria s

Concerns / Deficiencies:

1. CB-1A and B cooler drains were cross-connected. , ,

2. Control room dampers for CB-2 and CB-12 do not meet single f ailure criteria.

3. CB-1 outside makeup damper may not meet single failure criteria.

4. High radiation signal should automatically initiate emergency ventilation the same as a safety injection signal.

Conclusion:

The CB-1 system itself meets single failure criteria. Some components that could effect the control room envelope do not meet sig'"

criteria. '7 f ailure Corrective Actions:

1. CB-1A and B cooler drains have been separated.

2. Installation of two dampers for CB-2 and CB-12 is being evaluated.

3. No changes are planned for CB-1.

4. Automatic actuation of emergency ventilation on a high radiation signal is being evaluated, but should be considered a back fit.

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1 Control Room Ventilation Page 5 of 9

E. Charcoal Filter performance Concerns / Deficiencies:

1. Charcoal testing is not conducted at appropriate toppgratures and relative humidity to ensure 95% removal of methyl radiolodine as assumed in analysis. .

2. With a flow of 3.200 cfm i 10% results in residence time < 1/2 second, and therefore, efficiency < 95% removal of methyl radiolodine.

3. In-place DOP and freon tests should be based on .05% penetration not 1%.

Conclusion:

Charcoal and filter performance is still being evaluated, but presently it is . felt to be tested conservatively.

Corrective Action:

1. Charcoal test requirements will be reviewed and changed to ensure a 95% removal for methyl radiolodine which was assumed in analysis.

Technical specifications will be changed accordingly.

2. Actual flow conditions have been about 3,000 cfm. Flows required to ensure removal efficiency of 95% will be evaluated and implemented.

Technical Specifications will be changed accordingly.

3. In-place DOP and freon testing being evaluated, but the reason forI this concern is not clear.

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F. Control Room Heat Load and Temperature Concerns / Deficiencies:

1. Control room equipment is monitored at an incorrect location.

2. Heaters should be turned on instead of set at 70% to cycle on as humidity increases above 70%.

Conclusion:

The control room air temperature is being maintained < 110*F as designed and required by Technical Specifications.

Corrective Actions:

1. Control room temperatures and heat load are being evaluated, but any changes should be evr.luated under back fit requirements. '

2. The basis for turning the heater on during testing (other than drying out the charcoal) is not understood since these are not the conditions during actual operations. This should be evaluated unda back fit requirements.

Control Room Ventilation Page 7 of 9

C. Technical Specifications and Procedures Concerns /Deficiencly:

1. Toxic gas monitors and control room ventilation should be operable in all modes.

2. Analysis indicates that control room isolates in three seconds at a concentration of 1 ppm. Technical specifications show actuation at i 5 ppm. i

3. Several procedural discrepancies have been identified.

Conclusions:

Technical Specifications and procedures can be improved.

Corrective Actions:

1. Technical Specification changes will be submitted to be consistent with standard Technical Specifications.

2. Technical Specification changes will be submitted to be consistent with analysis.

3. All procedural discrepancies will be reviewed and procedures revised.

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i DRK:bjp 70133z Control Room Ventilation Page 8 of 9 l

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, CONTROL ROOM HVAC OPgRATION CB-2 CB-2 CB CB-1 ,C4-1 CB-5 Recire M/U 3&4 Fans M/U CB-10 Closed (2)

Normal Operations ON ON ON OFF Red Flagged ON SIS OFF OFF OFF ON Open OFF High Radiation Auto OFF OFF OFF OFF Closed (2) OFF Red Flagged Manual (1) OFF OFF OFF ON Open OFF Toxic Gas Auto ON OFF OFF OFF Closed (2) OFF Red Flagged Manual (1) OFF OFF OFF ON Closed OFF POT-20-1 Test OFF OFF OFF ON Closed OFF Carbon Dry ON ON ON ON Closed ON (1) Manual actions are actions required by ONI-12 or ONI-54.

(2) Damper is normally closed (green light) with control switch red flagged.

This allows damper to auto open when CB-1 starts. If switch is green l flagged, damper will not open when CB-1 starts.

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FUNCTIONAL DIAGRAM ._ Ed Q~ "" "Et {_

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(As-Foemd Flow Rates) Left cload daring SI /

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actuation h SI actuation Bormal Outside Al V l w 17 5 ete (d.mpw 90*od et, pa.:44eal Supply Fan 450 cfm

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