ML20197F251

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Forwards Request for Addl Info Re Control Room Habitability. Control Room Ventilation Sys Functioning Inconsistent W/Tmi Action Plan Item III.D.3.4 or Updated FSAR
ML20197F251
Person / Time
Site: Trojan File:Portland General Electric icon.png
Issue date: 05/07/1986
From: Chan T
Office of Nuclear Reactor Regulation
To: Withers B
PORTLAND GENERAL ELECTRIC CO.
References
TASK-3.D.3.4, TASK-TM TAC-61289, NUDOCS 8605150499
Download: ML20197F251 (14)


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May 7, 1986 DISTRIBUTION L Focket File NRC PDR Docket No. 50-344 L PDR Gray File PAD-3 Rdg H. Thompson OELD E. Jordan B. Grimes J. Partlow T. Chan C. Vogan Mr. Bart D. Withers ACRS 10 Vice President Nuclear Portland General Electric Company 121 S.W. Salmon Street Portland, Oregon 97204

Dear Mr. Withers:

SUBJECT:

CONTROL ROOM HABITABILITY FOR TROJAN - REQUEST FOR ADDITIONAL INFORMATION On January 28-30, 1986 and February 25-27, 1986 NRC representatives visited the Trojan Nuclear Plant to discuss with Portland General Electric (PGE) the NRC's control room habitability survey at Trojan, and a Technical Specification change request involving the performance of a steveillance test of the emergency air conditioning unit.

Based on information gathered during the two visits, the team members concluded that the manner in which the control room ventilation systems functioned did not appear to be consistent with the PGE TMI Task Action Plan Item III.D.3.4 subniittal or the updated FSAR. The team's conclusion was based upon the findings presented in Attachment 1 to Enclosure 1 and reflects inconsistencies in the as-found and as operated condition of the control room ventilation system and the control room envelope, and the Trojan III.D.3.4 analysis. The team also identified deficiencies in the technical specifications and the plant procedures, instructions, etc. utilized to demonstrate control room habitability in accordance with III.D.3.4. These are included as Attachments 2 and 3.

Because of deficiencies noted in the plant visits between the original TMI Action Plan III.D.3.4 analyses dated January 2 and March 2,1981 and the as-found condition, we believe that the conclusions reached by the staff in our Safety Evaluation dated February 17, 1982 may have been invalidated.

The enclosed request for additional information identifies items which must be addressed in order for us to assess control room habitability (III.D.3.4) at Trojan. Your response to this issue should be provided to us in a time frame which would permit staff review and resolution prior to Trojan restart following the April 1986 refueling outage, l

8605150499 860507 4 DR ADOCK 0500

r-Mr. Bart D. Withers 2 May 7, 1986 The reporting and/or recordkeeping requirements of this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, Terence L. Chan, Project Manager PWR Project Directorate No. 3 Division of PWR Licensing-A

Enclosure:

As stated cc w/ enclosure:

See next page

  • SEE PREVIOUS PAGE FOR CONCURRENCE OFC : PAD #3*  : PAD #3

_____:____________:____ ;gd[. ,..:____________::______..____:______..____:....._______.___..._____

NAME :CVogan :TCha ;ps'  :  :  :  :

DATE :5/7/86  :  :  :  :  :

5/ 7 /86 OFFICIAL RECORD COPY

r Mr. Bart D. Withers The reporting and/or recordkeeping requirements of this letter affect fewer .

than ten respondents; therefore, 0MB clearance is not required under P.L.96-511.

Sincerely, Steven A. Varga, Director PWR Project Directorate No. 3 Division of PWR Licensing-A'

Enclosure:

As stated cc w/ enclosure:

See next page 4

  • 7 0FC : PAD #3  : PAD #3 :D/ PAD #3  :  :  :

_____:._____yyy .._.._______:__.............______......__________ .___ _______......______

NAME :CVogan ___:TChan;ps

:SVarga  :  :  :

DATE :5/4 /86 :5/ /86- :5/ /86 ':  :  :  :

OFFICIAL RECORD COPY 4

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1 Mr. Bart D. Withers . .

Trojan Nuclear Plant

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Portland General Eletric Company .

cc:

Senior Resident Inspector U.S. Nuclear Regulatory Commission s 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  :

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ENCLOSURE 1 l REQUEST FOR ADDITIONAL INFORMATION ON THE TROJAN CONTROL ROOM An NRC team inspected the capability of the Trojan control room to meet GDC-19 during a February 25-27, 1986 visit. A team also visited the Trojan site on January 28-30, 1986 in conjunction with NRC's control room habitability survey at operating plants and for the purpose of discussing a technical specification change involving the I perfonnance of a surveillance test of the emergency air conditioning unit.

] ,The survey and inspection of the Trojan control room identified inconsi.stencies in Portland General Electric Company's III.D.3.4 submittal g

- and in the manner in which the system actually operated compared to the

way the system was described as operating. The NRC team concluded that Trojan did not meet the criteria of III.D.3.4. Attachment I lists the '

Trojan control room deficiencies and inconsistencies wit,h the III.D.3.4 submittal.

4 The NRC team's review of the technical specifications for the Trojan control room and some of the operating procedures and off-normal

instructions led them to conclude that the present Trojan technical specifications, procedures, and instructions may not be adequate in

! ensuring that the conclusions reached in your III.D.3.4 submittal are maintained. The team's coments are provided in Attachments 2 and 3.

Portland General Electric (PGE) should review Attachments 1, 2 and 3 and its III.D.3.4 submittal. PGE should provide a III.D.3.4 analysis which j accurately reflects the manner in which the Trojan control room will j operate during normal operation, during a toxic gas challenge and during a radiological challenge and which provides adequate demonstration that the Trojan plant meets the criteria of III.D.3.4. The staff finds unacceptable the use of KI tablets and respirators as a substitute for meeting the criteria of III.D.3.4. l I

l To assist the staff in its review of the revised III.D.3.4 submittal, each item of Attachments 1-3 should be addreseed, J

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Attachment 1 TROJAN PLANT CONTROL ROOM DEFICIENCIES A. RADIOLOGICAL

1. As of January 28-30, 1986
a. Unfiltered inleakage of 41 cfm existed through the' drain pipe from V-141A and B cooling coils. The estimated dose would be approximately 90 rem to the thyroid based upon the original Trojan III.D.3.4 submittal.

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b. Manner in which the system operates was inconsistent with the Trojan III.D.3.4 analysis which calls for a pressurization flow of 150 cfm.
c. Unknown quantity of inleakage existed from cross-connection of drain line between two filter trains.
d. Probable inleakage existed from normal makeup damper, standby emergency train damper, and high volume (CB-12) special exhaust damper. This was demonstrated by the fact that during a control room pressurization test the control room could be made positive with all outside dampers closed.
e. With external dampers all closed, control room envelope boundaries saw an unknown amount of inleakage because the control room was negative with respect to the surrounding boundaries.
f. Capability of charcoal was in question since technical 0

specifications call for test at 130 C and show a removal of 90% for methyl radioicdine. The licensee assumed a removal efficiency of 95% in their III.D.3.4 submittal and the test should be conducted at 30 0C.

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g. Flow of 3200 cfm +/-10% may result in a residence time in the adsorber of less than i second because the charcoal capability is based upon 3000 cfm. With a lower residence time adsorber efficiency would be significantly less than 95%.
h. Actions taken when ARM-11 alarms (Control Room Radiation Alerms)

- may not be quick enough to prevent radiation exposure. .

i. Because of the way the differential pressure is measured.(control room versus the normal makeup intake), it remains to be seen whether l the control room is positive with respect to the surrounding boundaries.

e i j. Outs.ide dampers do not meet single failure criteria.

2. As found February 28-30, 1986
a. Makeup in Train B showed approximately 450 cfm versus 150 cfm assumed in the Trojan III.D.3.4 analysis. The estimated dose corresponding to this makeup is approximately 50 rem thyroid.

Train A unavailable for measurements.

b. Normal makeup air duct showed 600 cfm of flow. Direction was uncertain. If inleakage, the estimated thyroid dose would be 900 rem.

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c. Same coments as those denoted in A.1 above. l l'

i l B. T0XIC GAS i ,

1. Operation of V-141A and B. VC-148 and V-142A and B may result'in an extremely negatively pressurized control room. Pressure exerted on outside dampers could be significant. Measurements should be made to verify system inleakage. l l
2. Continued supplying of air to the lunch room, toilet and laboratory with CB-3 and CB-4 off could result in-these rooms being positively 1

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pressurized with respect to the control room. This would provide a l potential source of inleakage to the control room.

3. Operators do not put on a mask upon a toxic gas challenge but must rely upon their own sensing capability or securing a monitor to measure the toxic gases inside and outside the control room.

~ . Operator action is not Snediate. Timing could be critical.

4. Same connents as noted in A.I.a. A.I.c, A.1.d. A.I.1, and A.I.,i but the impact must be considered in tems of toxic gas.

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. l Attachment 2  !

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COMMENTS ON TROJAN TECHNICAL SPECIFICATIONS Technical Specification 3.3.3.6, "C1, Detection System"
1. It would seem reasonable that Cl pdetectors should be operable during all modes.
2. III.D.3.4 analysis indicates that the control room isolates in 3 seconds at a concentration of 1 ppm. Technical specifications show

< actuation at less than or equal to 5 ppm.

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3. The C1 2 detector does not appear to have a channel functional test.

Technical Specification 3.3.3.12. "SO,, Detection Systems"

1. Same comment as item 1 above for the C1 2 detectors.

Technical Specification 3.7.6.1, " Control Room Emergency Ventilation System"

1. Ventilation system should be operable under all modes. The degree of operability varies between modes 1-4 a'nd 5-6.
2. Laboratory tests for charcoal should be conducted at 300C rather than 130 C, should utilize ASTM method D3803-1979, and should be conducted at 70% relative humidity if the heaters are always energized. That means on and not energized to cycle on when relative humidity reaches 70%. If the preheaters are deleted from the system the laboratory test should be conducted with the  !

relative humidity at 95%. l l

3. In-place DOP and freon tests acceptance criteria should be based upon 0.05% penetration not 1%. l l
4. Laboratory tests of charcoal should show a removal efficiency greater than that assumed in the III.D.3.4 analysis. A 95%

adsorption efficiency corresponds to a penetration of 1%.

5. System should be directing its inlet and recirculation flow through the HEPA filters and charcoal adsorbers on a high radiation signal

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in addition to the safety injection signal.

6. Control room pressure should be demonstrated positive with respect to surrounding areas and not to the outside atmosphere.
7. Control room equipment temperature is monitored at an incorrect location.

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8. Heaters should demonstrate kW rating if they are going to be incorporated into the control room ventilation system.

There appears to be a need for a technical specification addressing the NH 4

detectors.

Attachment 3 COMMENTS ON PROCEDURES AND OFF-NORMAL INSTRUCTIONS PET-10-1

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1. MP-9-1 section II.B.6 seems to indicate that the critical pressure drop in HEPA filters and charcoal adsorbers is 3" W. G. while surveillance requirements 4.7.6.1.d.1 indicates 6" W. G. This should be clarified. Refer to 5.1 of PET-10-1.
2. PET-10-1 would seem to require that TS 4.3.3.6 and 4.3.3.12 be included in Section 2.

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3. Section 8.2.1.2 of PET-10-1 seems to imply that the containment charcoal is replaced rather than a laboratory test performed. ANSI N510-1975, Table 1, is quite specific in requiring a test of charcoal prior to installing it (Containment System).
4. CB-1 is designed for 3000 cfm (i.e., 3 HEPA filters at 1000 cfm per filter and 9 charcoal adsorber trays at 333 cfm/adsorber tray).

System design is 3200 cfm. Design flow +/- 10% would cause residence time to be reduced from an assumed 0.25 seconds to approximately 0.20 seconds. Consequently, the adsorption efficiency would decrease.

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5. Air flow capacity test (8.2.2.4 of PET-10-1) should be demonstrated with the dampers DM-10251 A (B) opened in one case and closed in the other. l
6. When you remove charcoal from the spent fuel pool exhaust treatment system by taking a sample from the tray then the integrity of the system has been broken and a new in-place freon test is required (PET-10-1,Section8.2.3.2).

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7. Acceptance criteria in 9.9 of PET-10-1 should be 0.125" W. G. not 0.10".

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8. Acceptance criteria 9.10 of PET-10-1 should also include responding to a l safety injection signal.

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9. Step 8.5 of PET-10-1 should specify which of the DM-10250 dampers are to be open.

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10. What is VP-142 in Step 8.5 of PET-10-1?
11. Step 8.5A of MP-10-A should delete DM-10504 since this line has been capped off. Dampers DM-10251A and B should be verified as closed along with DM-10503 on Step 1 and DM-10251A and B are opened.

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12. Step 8.5 should also be demonstrated using a safety injection signal.
13. It would appear that step 8.5B of Data Sheet 8 of PET-10-1 should include a closure of the inner redundant damper of outside air intake.

14 System components verified as operating in Step 8.5A of Data Sheets 9,10 and 14 (PET-10-1) should be the same as -Data Sheet 8. Appropriate components which stop are similar.

15. Data Sheet 11, page 4 of 4, the item dealing with CB-1 and the 502 test requirement, should refer to Technical Specification 4.3.3.12.
16. Data Sheet 12, CB-1 control room positive pressure test, should have V-141 A and B instead of VC-141 A and B. DM-10251 A (B) should be opened with the other closed when the test is run. DM-10503 should be closed.
17. The visual inspection described in Data Sheet 15 should conform to Appendix A on ANSI N510-1975 as required by the Technical Specification.

18 It would appear from Data Sheet 9 of PET-10-1 that the operation of the fans V-141 A and B and VC-148 is uncertain. It is not clear

whether they are operating in the norwal configuration and continue to operate after the C1 2 signal or whether they are not operating.

The status of these fans should be addressed in Data Sheets 9 and 10.

PICT-25-1

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~1. It would appear that PICT-25-1 should demonstrate a channel functional test and a channel calibration test.

2. PICT-25-1 and PICT-25-2 do not agree. The former says that its purpose is to assure that the detector will cause the control room ventilation damper to isolate while the latter indicates its

' purpose is to assure that the detector system will shift the

( control room ventilation system to the emergency ventilation recirculation mode. Data Sheet 9 of PET-10-1 indicates that the normal control system operates in the recirculation mode on a C1 2 signal.

ONI-54, Rev. 2

1. Under irrediate operator actions DM-10251 A and ~B should already be closed unless a radiation challenge has occurred to the control room. Therefore, verifying that they are closed seems to be the appropriate action. The operator should put the face mask on since he or she has no way of knowing what the concentrations are and whether they are life threatening.
2. Why are both emergency fans 142 A and 142 8 started in the recirculation mode? Why wouldn't just one be started?

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3. Danpers associated with VC-141, CB-3 and CB-4 should be shown to be closed also.

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, ONI-12 l

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1. Based upon reading this instruction it appears that the operators ,

should initiate the CB-1 system and the dampers associated with the system.

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PICT-25-2

1. The objective (VII) should be to demonstrate that the C1 2

detection system will detect a C12 concentration less than or equal to 5 ppm and not at a concentration greater than 5 ppm.

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POT '20-1, Rev.16 5 -

1. How is it determined that the preheat coil will initiate at 70% relative humidity? What test has demonstrated that they initiate at this relative humidity?
2. POT 20-1 does not satisfy the Technical Specification because the heaters are not on during emergency ventilation system operation.

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