ML17279A544
| ML17279A544 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 08/31/1987 |
| From: | Hayes J Office of Nuclear Reactor Regulation |
| To: | Samworth R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8709030208 | |
| Download: ML17279A544 (52) | |
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~~g 8 1 198'7 MEMORANDUM FOR:
Robert B. Samworth, Senior Project Manager e
Project Directorate V
Division of Reactor Projects-III, IV, V 5 Special Projects FROM:
SUBJECT:
John J.
Hayes, Jr., Project Engineer PD II-1 Division of Reactor Projects I/II SURVEY OF WNP-2 CONTROL ROOM Enclosed is a copy of the NRR and Argonne National Laboratory (ANL) reports providing the results of the control room habitability survey of WNP-2.
This is the sixth of eleven plants visited.
This is the eleventh report issued.
When all of the rep'orts have been issued the overall findings will be presented in a NUREG/CR.
The findings of this survey are enumerated in Enclosures 1 and 2.
Enclosure 1
is the ANL summary report on the survey, while Enclosure 2 is NRR's report.
These findings have been discussed with the licensee at the exit meeting and in a subsequent telephone conversation.
Consistent with the August 8, 1985 memorandum to Dennis Kirsch of Region V from Dan Muller, NRR, a copy of these reports is being provided to the Region.
During the period of April 7-10,
- 1986, a survey was conducted at WNP-2.
The survey was performed by John Driscoll and Chuck Matthews of Argonne National Laboratory, Dennis Willett of Region V, and me.
The purpose of the survey was to evaluate:
(1) the operation of the control room ventilation system and its ability to maintain the WNP-2 control room habitable and (2) the adequacy of the technical specifications and procedures to demonstrate system operabil-ity and capability consistent with the assumptions made in the plant's safety analysis and the NRC's staff's associated safety evaluation.
07/31/87 WNP-2 CONTROL RM SURVEY/HAYES
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Robert B. Samworth The survey team gathered flow rate data in various portions of the control room ventilation system with the system operating in its normal mode of operation.
In addition, data were also gathered with the ventilation system operating in its emergency radiological and toxic gas operating modes.
The survey team's findings cover system operation and design, plant technical specifications and procedures, and the safety analysis.
As a result of this survey, the team has concluded that the present state of the control room habitability system at WNP-2 is such that the following items need to be addressed:
1) the present capability of the control room habitability system to operate in a manner consistent with its safety analysis and the NRC staff's safety evaluation; Based upon the flow measurement
- data, the amount of unfiltered inleakage seems to be considerably greater than the zero assumed in the licensee's safety analysis.
2) system has inherent design flaws; Diversion valves/dampers are, susceptible to single failure which could lead to significant quantities of unfiltered flow to the control room and negate the present conclusions on the acceptability of the system.
Both emergency chiller units are located adjacent to each other and are susceptible to being made inoperable by a fire.
Backup control room cooling source, while safety-related, has an insufficient capacity to handle the cooling load during some summer conditions.
Therefore, control room temperature may not be maintained.
3) technical specifications are insufficient to ensure that the assumptions presented in the WNP-2 safety analysis and the NRC staff's safety evalua-tion remain current and that the control room habitability system will 07/31/87 WNP-2 CONTROL RN SURVEY/HAYES
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Robert B. Samworth perform its intended function as described in the safety analysis and the staff safety evaluation; Refer to Attachment 2 of Enclosure 2 and Enclosure 1 itself for additional details.
4) procedures contain some errors which resulted in an inadequate demonstra-tion of the capability of the control room ventilation system to perform its intended function.
Refer to Attachment 3 of Enclosure 2 and Enclosure 1'itself for additional details.
5) whether radiation monitors are needed in normal outside air intake; There are no radiation monitors located in'he normal outside air intakes.
The control room habitability systems are only initiated for radiological purposes when an F, A or Z signal is received.
Therefore, there is no way of alerting the control room operators to a condition of a high radiation challenge if the incident which precipitated the event does not initiate one of these signals.
The question is whether there is such an accident
-as the above where the control room operator doses would exceed GDC 19 because of the lack of filtration and adsorption of the control room makeup air.
An example of such an accident might be a steamline break outside containment.
The licensee should perform an evaluation to determine if such an accident could occur at MNP-2 and if it could, then radiation monitors would need to be added to the normal intakes of the control room.
The system logic to initiate operation of the control room habitability system in its emergency radiological mode would need to incorporate this signal from the normal intakes.
By this memorandum I am requesting that a copy of these reports be provided to the licensee so that they may address the concerns which are outlined above and in the enclosed reports.
Those concerns which involve plant procedures and 07/31/87 WNP-2 CONTROL RM SURVEY/HAYES
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Robert B. Samworth compliance with technical specifications will ultim'ately be the responsibility of Region V to resolve.
Those concerns which involve operation in accordance with the safety analysis and its associated safety evaluation and the adequacy of plant technical specifications will be the responsibility of NRR to resolve.
John J.
Hayes, Jr., Project Engineer PDII-1 Division of Reactor Projects I/II cc:
J.
Craig J. Driscoll (ANL-W)
R. Pate (Region IV)
D. Kirsch (Region V)
R.
Dodds (WNP-2, RI G. Knighton PM: PD21: DRPR JHayes 8/gW/87 07/31/87 I
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Robert B. Samworth DISTRIBUTION:
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Hayes 07/31/87 MNP-2 CONTROL RN SURVEY/HAYES
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ENCLOSURE 1
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WNP-2 Nuclear St,ation Page 1
PLANT VISIT
SUMMARY
REPORT 1.
Plant:
WNP-2 Nuclear Station 2.
Uti lity:
Washington Public Power Supply System 3.
Location:
Hanford, Washington 4.
HRC Region:
V 5.
Visit Oate:
April 7-10, 1986 6.
Participants from Argonne National Laboratory:
J.
W. Oriscol 1 C.
E. Mathews III 7.
Scope:
P'he plant visit was made to gather information on control room habitability Generic Issue 83.
As a part of the review, the Plant Technical Specifications were reviewed and compared to the safety analysis (including III.O.3.4. submittal and the HRC staff safety evaluation) and plant procedures to determine what opera-tional practices are being employed.
System airflow measurements were made to determine the unfiltered air inleakage into the control room envelope.
8.
Findings:
8.1 General The WNP-2 Control Room HVAC System is divided into two redun-dant trains which are completely separated except that common supply ducting for distributing air to the control room and common makeup air ducts are shared by the two systems.
The two chiller units for the emergency cooling coils are located in the same area with no physical barrier separating them.
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ENCLOSURE 1
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The air handling units for each train contains a nonsafety grade cooling coil and a safety grade cooling coil.
The safety grade cooling coils are served by an associated safety grade chilled water system and by plant service water; The'mergency filtration system functions as an integrated part of the main HVAC system and as operated will not function without the main ventilation supply fan in operation.
With exception of the air handling units, the construction of the WNP-2 control room HVAC system is one of the best we have seen to date.
Reg.
Guide 1.5.2, "Design, Testing, and Maintenance Criteria for Post Accident ESF Atmosphere Cleanup Systems Air Filtration and.Adsorption Units of Light Water Cooled Nuclear Power Plants,"
Item 5.c states, "The use of silicone sealant or any other temporary pytching materials on filters,
- housings, mounting frames, or ducts should not be allowed."
Sealant compounds are used extensively on ductwork joints at WNP-2.
8.2.
Procedures The procedures at WNP-2 are very clear as to their purpose and are well referenced to the Plant Technical Specifications.
The procedural steps are easily followed except that equipment numbers are used without any nomenclature, i.e.,
"WMA-FN-51A" instead of WMA-FN-51A, Control Room HVAC Fan 51A."
8.2.1 The Plant Safety Analysis assumes that operators will put on air breathing apparatus in the event of a high C12 signal, Procedure 4.10.3. 1, "Control Room HVAC High Radiation or Chlorine Induction," should contain a step requiring the operator to put on pro-tective air breathing equipment.
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ENCLOSURE 8
~'WNP-2 Nuclear Station Page 3
8.2.2 Procedure 2.10.3,'ontrol,
- Cable, and Cri&cal Switchgear Rooms HVAC, requires the refrigrant com-pressor CCH-CR-1A oil heaters to be energized for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> prior to starting the chiller.
CCH-CR-18 is auto start by an F and an A signal.
There is no
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caution to routinely verify that the heaters in these trains be energized.
If compressor CCH-CR-18 does not have its oil heater on continuously then the compressor should be considered inoperable.
8.2.3 Emergency filter in-place penetration, bypass leak-
- age, aP and OOP tests are required by technical specifications to be performed at 1000 cfm flow.
Procedure 7.4.7.2.4, "Control Room Emergency Filtra-tion Sy'tem - Flow and Pressure Orop Tests," deter-mines system f,low but is not required as a prereq-uisite for any of the procedures performing the above surveillance tests.
Procedure 7.4.7.2.4 should be listed as a prerequisite in appropriate plant procedures.
8.3
~S The Control Room (CR)
HVAC system was found to be as described in the USAR and material provided by the utility (WPPSS),
except as follows:
8.3.1 The radiation dose to control room operators during a
LOCA is based on 74 cfm ingress-egress and damper and filter frame bypass leakage.
The 6-inlet dam-pers are assumed to have zero leakage (FSAR Table 6.4-1).
Me measured leakage in excess of 100 cfm on remote intake fl and in excess of 130 cfm of intake f2.
The normal intakes were the tightest with about 21 cfm leakage.
These measurements were made with the system in the FAZ mode of operation.
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ENCLOSURE 1 ~
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- 8. 3.2 The toilet and kitchen exhaust damper is assumed to have a leak rate of 11.25 cfm (FSAR Table 6.4-1).
The leak rate across the exhaust fan damper was measured to be in excess of 35 cfm.
8.3.3 The damper leakage of most concern is the leakage across dampers 51A-1 and 51B-1 because leakage across these dampers would bypass the charcoal adsorbers.
W'e measured in excess of 90 cfm leakage across damper 51A-1 with a train operating in the FA2 mode of operation.
The test ports were not positioned to obtain leakage across 51B-1.
Failure of either of these dampers does not meet the single failure criterion.
8.3.4 The utility shpuld collect flow data on the system and determine leakage across all valves.
The radiation exposure to the control room operator should then be recalculated based on the system leakage measured.
8.4 Technical S ecifications The following changes are recommended to the WNP-2 Technical Specifications and/or control room HVAC system to better oper-ate and perform surveillance of the control room HVAC system.
8.4. 1 Surveillance requirement 4.7.2.b should require the charcoal adsorber to be energized and not just oper-able.
8.4.2, Surveillance requirement 4.7.2.a requires monitoring the control room temperature once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to verify the control room temperature is < 85'F.
This requirement does not make any assumptions as to what cooling coils are in service.
A new requirement
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ENCLOSURE 1
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should be written requiring the emergency~oling coils to be placed in service for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> on a monthly basis and verify that the design temper-atures can be met with the emergency chiller in '.
operat1on and with service water being used as the cooling medium for the emergency cooling coils.
8.4.3 Surveillance requirement 4.7.2.d should be revised to require the laboratory sample to be performed at 30'C instead of 80'C.
The temperature, relative humidity and test method should be specified.
The test should be in accordance with ASHE 0-3803.
8.4.4 Surveillance requirements 4.7.2.f and 4.7.2.g requires a system bypass test after complete or partial replacement of HEPA filters or charcoal adporbers.
Following these replacements an 1n-place test is required, not a systems bypass test.
The system bypass test is required on an 18-month inter-val.
The bypass test as now performed is not adequate.
The injection points are not far enough upstream of the filter and adsorber and the monitoring points are not far enough downstream.
8.4.5 Table 3.3.7. 1-1 indicates that there should be two radiat1on monitors per intake.
There are no radi-at1on monitors on the normal intake.
8.4.6 A surveillance requirement should be added to ensure that the charcoal adsorber preheaters are energized when the relative hum1dity increases to 70K.
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ENCLOSURE 1
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8.4.7 Surveillance requirement 4.7.2.C.1 speciHi s that the in-place penetration and bypass leakage testing of the HEPA filters and charcoal adsorbers be per-formed with system flow at 1000 cfm + 10X.-
The system flow criteria should be 1000 cfm + lOX.
8.5 HVAC Flow and CRE Tem erature Heasurements 8.5.1 Air temperature was measured in the control room with the unit shut down and the control room HVAC system operating in its normal mode.
The control room ambient temperature averages F.
The tem-peratures taken inside of instrument cabinets aver-aged F.
- 8. 5.2 Ajr flow data was taken with the system operating in the normal configuration.
The FA2 pressurization mode and the Cl2 isolation grade.
Oata was taken with train A operating and with Train B operating for each mode of operation.
8.5.3 The data taken indicates that there is significant leakage across isolated remote intake valves
(>100 cfm).
8.5.4 The emergency filter trains have very little flow through them when their associated inlet dampers are closed.
8.5.5 The toilet and kitchen exhaust fan damper leakage was
> 35 cfm.
8.5.6 There was a significant flow through the standby air handling units on each data set.
The utility should
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ENCLOSURE 1(I WNP-2 Nuclear Station Page 7
determine what the source of this airflow ds and if it has any inpact on the GDC-19 criterion.
8.5.7 With the system operating in the C12 isolat4on mode.
There was about 170 cfm of outleakage across the three sets of intake valves with the A train in operation.
When the 8 train was placed in opera-tion, there was about 185 cfm of leakage into the system.
The utility should determine the significance of the inleakage vs. the outleakage with different trains in operation and what impact this might have on toxic gas exposure of control room operators.
8.6 Outside Air Infiltration The WNP-2 Safety Analysis assumes an unfiltered air inleakage of 74 cfm.
The measurements taken with the system operating in the FAZ mode of operation indicates that this value may be low.
Air leakage across damper 51A-1 could indicate an unfiltered of > 90 cfm.
The utility should conduct a complete survey of the control room HVAC system to determine actual inleakage and recalculate control room operator exposure based on these measurements.
8.7 LER Evaluation There were no LER's associated with the loss of cooling to the control room envelope.
Adequate surveillance tests of the safety grade cooling system is not being performed.
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ENCLOSURE 2
.NRR FINDINGS
'HNP-2 CONTROL ROOM By:
Jack Hayes X27214
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ENCLOSURE 2
NRR Findin s
WNP-2 Control Room On April 7-10,
- 1986, Dennis Willett of Region V, Jack Hayes of the Plant Systems Branch (PWRL-A), and John Driscoll and Chuck Matthews of Argonne National Labora-tory (ANL) met with representatives of the Washington Public Power Supply System (WPPSS) to perform a survey of the WNP-2 control room habitability system.
WNP-2 was the sixth in a series of surveys of operating plants.
The purpose of the survey was to evaluate:
(1) the operation of the control room habitability system and its ability to maintain the WNP-2 control room habitable and (2) the adequacy of the plant's technical specifications and procedures to demonstrate system operability and system capability consistent with the assumptions made in the plant's safety analysis and the NRC staff's associated safety, evaluation.
F The staff of WNP-2 was the first that the survey team encountered which seemed to have a good understanding of the manner in which the control room habitabil-
'C ity system is to be operated.
They appeared to have spent some time with the system trying to ensure that it functions properly.
Like other facilities which have been visited, they did not have adequate test ports in order to evaluate whether the system functions as it was intended.
However, they did add additional test ports and exerted great effort in having them installed so that flow data could be obtained.
- However, an insufficient number of test ports were installed to be able to address total system performance and integrity.
Because an insufficient number of test ports were installed, the flow data could only reveal the integrity of the isolation valves and some of the flow diversion dampers.
There were an insufficient number of test ports to be able to perform flow measurements and thus, a flow balance across the air handling units, the recirculation fans, and the emergency filter units.
Such measurements are critical in determining system performance and integrity.
This is particularly true for WNP-2 where the control room ventilation equipment and fts associated ductwork is outside the control room envelope and the determination of unfiltered WNP-2 CRH SURVEY ENCL 2 07/31/87.
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inleakage is so critical.
A considerable amount of inleakage in these types of designs is not unusual.
Attachment 1 contains comments on the system performance as concluded from the flow data.
The survey team believes that the only way for WPPSS to determine whether WNP-2 is meeting its design bases is for additional flow measurements to be made.
The licensee should install the additional test ports and perform these flow measurements and determine whether the facility is meeting its licensing bases (i.e., General Design Criteria 19).
The plant technical specifications reflect many of the same deficiencies identfied during other plant surveys.
One of the more important ones is the lack of demonstration of the capability of the safety grade chilled water system (emergency chilled water system).
Attachment 2 contains additional comments on the technical specifications.
Plant procedures looked to be clear and. very usable.
Their numbering correlated to technical specification pur veillance requirements which the survey team found convenient.
Some problems were identified with the procedures.
Attachment 3
contains comments on the procedures.
A review of the WNP-2 control room ventilation system showed that there is a
design flaw in th'at the control room is susceptible to a single failure while in the emergency pressurization mode.
Failure of any one of dampers 54A-2, 51A-l, 54B-2 or 51B-1 would result in unfiltered air entering the control room.
Depending upon the volume of the air, this failure could negate the conclusion reached by the staff concerning WNP-2 meeting GDC-19.
The plant also seems to have a design problem because of the lack of physical separation between their emergency chillers, CCH-CR-1A and CCH-CR-1B.
Because there is no physical separation, a fire could result in both chillers being lost.
This results in the loss of emergency chilled water.
In that case, the cooling coils of the control room air handling unit must be supplied water from the standby service water system.
Discussions with WNP-2 staff indicated that the standby service water system may be inadequate in'aintaining the control room WNP-2 CRH SURVEY ENCL 2 07/31/87
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~l at a temperature at which control room equipment qualification temperatures would not be exceeded during certain summer conditions.
This des~
inadequacy should be addressed by the licensee.
There are no radiation monitors located in the normal outside air intakes..
The control room habitability systems are only initiated for radiological purposes when an F, A or Z signal is received.
Therefore, there is no way of alerting the control room operators to a condition of a high radiation challenge if the incident which precipitated the event does not initiate one of these signals.
The question is whether there is such an accident as the above where the control room operator doses would exceed GDC 19 because of the lack of filtration and adsorption of the control room makeup air.
An example of such an accident might
. be a steamline break outside containment.
The licensee should perform an eval-uation to determine if such an accident could occur at MNP-2 and if it could, then radiation monitors would need to be added to the normal intakes of the control room and the system logic to initiate operation of the control room habitability system in its emergency radiological mode would need to incorporate the signal from the normal intakes.
One comment to be made in terms of system quality is with regards to the doors of the air handling units which exhibited very poor quality of construction.
Leakage was evident all about these doors in both trains.
Since this equipment is located outside of the control room envelope it represents a major source of potential unfiltered. inleakage into the control room envelope.
Had sufficient test ports existed, then the extent of this problem may have been determined.
The staff of WNP-2 was extremely cooperative during the survey and recognized the benefit of having additional test ports which could be utilized in the future to confirm system performance.
Mhile the system integrity was not the best encountered, it is better than some.
It did exhibit some unusual perfor-mance characteristics, possibly as a result of ductwork design and layout.
Me believe that while the data gathered is informative, additional test ports are required in order to allow WNP-2 to assess whether its control room habitability system is functioning as intended.
MNP-2 CRH SURVEY ENCL 2/HAYES 3
07/31/87
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,ATTAcHNENT 1 0
0 COMMENTS ON OPERATION OF WNP-2 CONTROL ROOM VENTILATION SYSTEM
SUMMARY
Flow measurements were taken in various portions of the control room-ventilation system ductwork with the system in its normal configuration, first with air handling unit WMA-AH-51A and fan 51A operating and then with air handling unit WMA-AH-51B and fan 51B operating.
This was followed by flow measurements with the system operating in its emergency pressurization mode as would occur during a radiological challenge to the control room.
With emergency filter unit FU-54B operating along with the 51B fan and its associated air handling unit, flow measurements were taken with both remote air intakes
- open, then with one remote intake isolated and the other open, and then with the opened and closed remote intake switched.
With the remote intake dampers in this latter configuration flow data were obtained with the emergency filter unit FU-54A operating and air handling unit WMA-AH-51A and fan 51A operating.
Flow measurements were also made with outside air intakes isolated ps would be the case for the toxic gas challenge.
Specific comments on operation in each mode follow.
Flow data are included as Table 1 of this attachment along with the system configuration for each data set.
Figure 1 is a system diagram.
Flow rates shown on Figure 1 are system design flow rates not those actually measured.
The flow data were insufficient because flows could not be obtained both up-stream and downstream of air handling units, filter units, and intake isolation and flow diversion valves and/or dampers because an inadequate number of test ports were installed.
- Thus, no flow balance could be made on these components.
In some cases the upstream data were available but not the downstream.
In other instances the situation was reversed.
Consequently, the amount of unfiltered inleakage could not be'etermined and no assessment could be made as to the integrity of the ventilation system ductwork, the fan housings and their shafts, the air handling units, or the emergency filter unit housings and their fans and shafts.
This lack of data also affects the degree by which one can pin-point the leakage past isolation valves and flow diversion valves with the latter affected most.
These data are critical and essential if one is to be able to assess system performance in addition to integrity and are crucial for those systems where the majority of the ventilation system equipment is outside WNP-2 CRH SURVEY ATT 1 07/31/87
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the control room envelope and the system fans and air handling units are interconnected and susceptible to system interactions.
This is the-case at WNP-2.
Some general conclusions which can be drawn from the data are:
1)
Outside makeup air is less with fan AH-51A operating than when fan AH-51B is operating.
For the normal mode of operation this difference was 400 cfm.
For the radiological mode this difference was on the order of 100-120 cfm as long as only one remote intake was open (Normal and radiological II operating modes.)
2)
Leakage past the normal outside air intake was constant at about 20 cfm while that past the isolated remote intake valves ranged from 100-120 cfm.
Leakage past the toilet and kitchen exhaust damper averaged 30-50 cfm depending upon where the flow measurement was made (Radiological and toxic gas modes).
r.
3)
In the toxic gas
- mode, leakage past the normal and emergency outside air
.intake was determined to be as high as 187 cfm.
(Toxic gas mode).
4)
It is suspected that there is an interaction between the AH-51A and the AH-51B air handling units and their respective fans such that sources of
-unfiltered inleakage may be making their way into the control room unknown to the operator (All modes of operation).
Since the survey was conducted at the WNP-2 facility, all onsite sources of chlorine have been removed and operation of the control room emergency ventila-tion system in an isolation mode as was required in the event of a chlorine challenge is no longer required.
The following sections detail the results of the flow data taken in the various modes of operation.
WNP-2 CRH SURVEY ATT 1 07/31/87
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MODE SPECIFIC DATA Normal Operation Flow measurements were made initiallywith the WMA-AH-51A air handling unit operating (Data Set 1).
In this configuration the normal outside air intake provided 553 cfm of makeup and inleakage past remote intake dampers WOA-V-51A and WOA-V-52A measured 37 cfm and that past dampers WOA-V-51B and WOA-V-52B measured 16 cfm.
Total makeup from all sources equaled the exhaust from the kitchen and toilet.
Flow through the charcoal adsorbers was determined to be 94 cfm in train WMA-FU-54A and 15 cfm in train WMA-FU-54B.
Makeup flow to fan WMA-FN-51A measured 534 cfm.
The exhaust from this fan, which includes control room return flow, flow from the emergency filter unit, and flow from the outside air intakes, measured 17,882 cfm.
Flow through damper 54A-2 from the air hand-ling unit plenum measured 29 cfm while that for 54B-2 measured 10 cfm for air handling unit WMA-AH-51B.
Flow through the idle fan WMA-FN-51B measured 625 cfm.
This was probably backflow from the control room.
With the WMA-AH-51B air handling unit operating (Data Set 2); fan WMA-FN-51B showed a discharge of 15,630 cfm.
Outside air makeup from the normal intake measured 909 cfm while leakage past the remote intake isolation dampers increased to 67 cfm and 20 cfm for intakes 1 and 2, respectively.
The toilet and kitchen exhaust was 535 cfm.
There was little flow (less than 10 cfm) through filter train WMA-FU-54A while WMA-FU-54B showed 54 cfm.
The idle fan showed a flow of
- 596 cfm and leakage through dampers 54A-2 and 51A-1 measured less than 10 cfm and 32 cfm, respectively.
Based upon these measurements it can be concluded that with fan WMA-FN-51A operating over 2,000 cfm more air is supplied to the control room than with fan WMA-FN-51B operating.
However, with 51A fan operating the outside air makeup is only 60% of that when 51B fan is operating.
Flow through the idle fan is similar in both cases.
[With fan 51A operating outside air makeup equals exhaust while with 51B operating exhaust is approximately 50% of outside air makeup.]
Based upon experience gained at other plants and the flow data, one would suspect that there is an interaction between the FN-51A and the 51B fans and their associated air handling units and that in the one case the fan/air WNP-2 CRH SURVEY ATT 1 07/31/87
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handling unit is sometimes a source of inleakage and for the other unit a source of outleakage.
Flow through the filter train of the operating air&andling unit ranges from 5-10% of rated flow (54-94 cfm).
The isolation dampers of remote intake 1 do not maintain inleakage to as low a level as do the isolation dampers on remote intake 2.
Emergency Operation (Radiological Challenge)
Data were gathered with fan 51B operating with the normal outside air intake isolated and both remote intakes open (Data Set 3); then with fan 51B operating and all but remote intake 2 isolation dampers closed (Data Set 3A); with fan 51B operating and only remote intake 1 isolation dampers open (Data Set 3B) and finally with fan 51A operating and all isolation dampers closed except those in remote intake 1 (Data Set 4).
With fan 51B operating and both remote air intake isolation valves open (Data Set 3) leakage past the normal outside pir intake dampers was approximately 20 cfm.
Flows were 363 cfm from remote intake 1 and 454 cfm from remote intake 2.
Flows through the operating and idle fans were similar in volume to that measured during normal operation of the system.
Flow through the operat-ing filter unit did not approach that of the outside air makeup.
It was approximately 65K.
Flow to the operating fan approached that of the outside air makeup.
Leakage past dampers 51A-1, 54A-2, and 54B-2 exceeded 75 cfm.
When fan 51B was operating and remote intake 1 was isolated such that pressur-ization flow was only to come from remote intake 2 (Data Set 3A), over 100 cfm leaked.through the remote air intake 1 isolation dampers and 20 cfm through the normal intake isolation dampers.
When the source of the outside makeup air was switched from remote intake 2 to remote intake 1, leakage through the isolation dampers for remote intake 2 increased to 120 cfm (Data Sets 3B and 4).
This was with either fan 51A or 51B was operating.
Leakage through the normal intake isolation dampers remained unchanged.
Pressurization flow was approximately 100 cfm less when fan 51A was operating versus 51B.
When flow measurements were made in the ductwork with fan 51A operating (Data Set 4) flow through the filter unit was only 456 cfm while outside air makeup WNP-2 CRH SURVEY ATT 1 07/31/87
h
measured 736 cfm..Leakage through dampers 54A-2 and 51A-1 measured 29 and 92 cfm, respectively.
Flow through the idle filter unit measured g0 cfm.
Flow upstream of dampers 51B-1 and 548-2 measured 136 cfm yet flow downstream of these dampers measured 33 and 15 cfm, respectively.
Flows through both operating fan unit 51A and through idle fan 51B were 8-13% lower than during normal operation.
When the status of these two fans was switched, flow through the idle fan increased 15% while flow through the operating fan decreased 3X.
Leakage past the toilet and kitchen exhaust dampers WEA-AD-51 measured approxi-mately 30-40 cfm for all Data Sets in this mode of operation.
Emergency Operation (Toxic Gas Challenge)
The control room ventilation system was operated in its emergency isolation mode just as it would if WNP-2 experienced a toxic gas challenge.
All outside air intake dampers were closed as was the kitchen and toilet exhaust.
Initial flow measurements were with fan 51A operating (Data Set 5) and then with fan 51B operating (Data Set 6).
In taking the measurements with fan 51A operating, it was noted that at the remote intakes flow was out of the test port, i.e.,
P the ductwork was at a positive pressure with respect to the mechanical equipment room (Data Set 5).
For Data Set 6 with fan 51B operating flow was into the test ports, i.e., the ductwork was at a negative pressure relative to the room.
Because of the lack of adequate flow data, no explanation for this can be offered.
For both Data Sets leakage by the toilet and kitchen exhaust dampers was approximately 40 cfm.
Leakage through the normal isolation damper was 9 cfm, when 51A was operating and 21 when 518 was operating.
For remote intake 1, leakage through its isolation damper s measured 95 cfm and 126 cfm for the two Data Sets, while the leakage associated with remote intake 2 dampers measured 67 cfm and 40 cfm, respectively.
For emergency filter flow through the 54A filter unit (Data Set 5), flow was measured as 374 cfm while flow through the open damper 54A-2 was 776 cfm and through the closed 51A-1 damper was 34 cfm.
Flow upstream of dampers 54A-2, after the portion of the ductwork which heads to the 54A filter train, showed a flow of 1110 cfm which does not reflect a
balanced condition.
Flow past dampers 51B-1, 54B-1, and 54B-2 is relatively low (less than 20 cfm in the worst case).
Flow through the operating fan is WNP-2 CRH SURVEY ATT 1 07/31/87
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approximately 2.5X higher than normal operation while flow through the idle unit is virtually identical.
~W For Data Set 6 the operating fan 51B was at its highest flow of any case observed.
Flow was approximately 10$ higher than in any previous case.
For the idle fan, flow was slightly greater than Data Set 3.
Flow through the operating filter train was approximately 400 cfm while flow upstream of dampers 51B-1 and 54B-2 measured 669 cfm.
Flow past these dampers measured 841 and 350 cfm, respectively.
For the idle air handling unit, leakage past dampers 54A-1, 54A-2 and 51A-1 was 26, 17, and 42 cfm, respectively.
WNP-2 CRH SURVEY ATT 1 07/31/87
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TABLE 1 WNP 2 NUCLEAR STATION CONTROL ROOM HVAC SYSTEM FLOW DATA
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DATA SET 4
DATA SET 5
LOCATION DATA i
2 DATA SET 3B'ATA SET 3A'ATA SET 3 DATA SET 6
SYSTEM STATUS
'MODE OF OPERATION
'TRAIN IN SERVICE
,'INTAKES OPEN
'CL DIV1'CL DIV2',
FAZ FAZ
'NORMAL 'NORMAL FAZ FAZ
'REM.
'NORMAL 'NORMAL 'REM.1&2'REM. 2
'REM.
1 I
18,'
I 18 I
553 '09 I
I 37
,'67 I
21 21 OUTSIDE AIR INTAKE WOA-V-52C 21 I
I 593 134 I
I I
I 95 I
I 67 I
374 I
363 126 REMOTE INTAKE ¹1 WOA-V-51A/WOA-V-52A 593 I
454 I
I I
I I
12 I
40 122 731 16
,'20 I
I 94,'.6 I
I 29
<i5 i
I 534 '2 I
REMOTE INTAKE ¹2 WOA-V-51B/WOA-V-52B 3
I I
I I
I 26 456 EMERGENCY FILTER UNIT WMA"FU-54A SUPPLY I
I 6A I
17 776 29 DOWNSTREAM WMA"AD-54A-2 42 37 36 I
92 6B DOWNSTREAM WMA-AD-51A"1 I
I 706 18340 16506 688 596 17882 I
I DISCHARGE OF FAN WMA-FN"51A 6D I
I I
,'7A,'
350 I
I 30 I
I I5'0 I
I 10 15 DOWNSTREAM OF DAMPER WMA-AD-54B"2 I
I 1
I I
7P I
I I
17193 I
I 38 37 I
112 I
I 670 i
398 I
841 DISCHARGE OF FAN WMA-FN-51B 625,'5630 15109 542 62 I
31 42 I
I 128 I
I I 135 I
I 20 36 27 39 604 '35 10'8 TOILET EXH.
DOWNSTREAM OF ISOLATION VALVE I
I I
38 I
I I
42 50 10A'4 BETWEEN TOILET EXHAST FAN & EXHAUST DAMPER i
I 75 I
UPSTREAM DAMPERS WMA-AD-51A-1 & WMA"AD-54A-2',
I I
llA' 1100,'i I
I I
I I
I 592
,'51 I
I I
I 11B<
& WMA AD 54B 2<
I I
I I
I I
24 23 '31 I
15 558 I
I 873 I
15 53 12 i'ISCHARGE OF EMERGENCY FILTER WMA FU 54B I
I I
I 33 18 27 '57 I
l3,'RESH AIR & FILTERED AIR TO FAN WMA-FN-51B DOWNSTREAM OF WMA-AD-51B-1
'TRAIN A'TRAIN B'TRAIN B'TRAIN B'TRAIN B'TRAIN A'TRAIN A'TRAIN B'
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REMOTE INTAKE N1 1000 CFH VOA-V-51A VOA-V~A 0/1000 CFH 8
3 1000 CFH VOA-VWIB
~V-52B 0/1000 CFH REMOTE INTAKE N2 VHA FN EMERGENCY FI T R VHA~-54A 1000 CFM VHA AD 51A-1 6B SUPPLY AND RECIRCULATION 4
FAN VHA~-5IA BD 0/1000 CFH 54A-2 BD VGA-V-52C VOA-V-51C VHA AD 54B"2 0/1000 21,000 CFH OUTSIDE AIR CFH INTAKE PLENUH 1
VHA AD 51B-1 13 SUPPLY AND RECIRCULATION FAN VHA-FN-51B 21,000 CFH VHA AD 54B-1 EHERGENCY FILTER TRAIN VHAWU-54B 1OOO CFM VHA FN ED CD ED E9 AJ AIR HANDLING UNIT VHA-AH"51A 21,000 CFH 2j,ooo CFM AIR HANDLING UNIT
-AH-51B X
D 250 CFH EXFILTRATION 200 CFH SHIFT SUPERVISORS OF FICE 20,150 CFH CONTROL ROOM AND COMPUTER R
200 CFH OOM KITCHEN 650 CFH 100 CFH 100 CFH TOILET AND KITCHEN EXHAUST FAN VEA~-51 VEA AD 51 10 TO iDISCHAR4k PLENUM 750 CFH VASHINGTON PUBLIC POVER SUPPLY HANFORD UNIT 02 FIGURE 1
WNP2
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ATTACHNENT 2 COMMENTS ON WNP-2 TECHNICAL SPECIFICATIONS A review of the WNP-2 technical specifications and the manner in which the WNP-2 control room habitability system is operated has determined that deficiencies and inadequacies exist in the technical specifications.
A discussi6h fol'lows on what changes would be appropriate to the technical specifications.
3/4.7.2 "Control Room Emergency Filtration System" (1)
Surveillance requirement 4.7.2.b has the control room emergency filtration system train demonstrated as OPERABLE by initiating flow through the HEPA filters and charcoal adsorbers and verifying that the train operates for at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> with the heaters OPERABLE.
The heaters should be on and not set to cycle on when relative humidity exceeds 70$.
Therefore, the term "OPERABLE" should be replaced with the term "on" in this surveillance requirement.
(2)
The surveillance acquirements should include a monthly test to demonstrate that the heaters will actuate when a relative humidity of greater than 70$ is observed in the makeup air to the emergency filtration units.
Otherwise, there is no guarantee that the system is even capable of recognizing the relative humidity of incoming air.
If no test is performed, then the laboratory test for the charcoal should be based upon 95$ relative humidity.
(3)
There should be a monthly test sufficiently long in duration, possibly 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />, of the capability of the emergency chilled water system to maintain the equipment and instrumentation temperatures below their qualification temperatures.
However, discussions with the licensee have indicated that the ade-quacy of the standby service water probably cannot be demonstrated during certain conditions during the summer months.
The licensee should address this potential design inadequacy.
WNP-2 CRH SURVEY ATT 2 07/13/87
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(4)
The laboratory test conditions for the charcoal adsorbers should be based upon the ASTM D3803-1979 test method and should be-conducted at 30'C.
(4.7.2.c.2 and 4.7.2.d).
(5)
Partial or complete replacement of HEPA filters or charcoal adsorbers does not require a system bypass test.
An in-place test is sufficient.
(4.7.2.f and 4.7.2.g)
(6)
The in-place DOP and Freon tests should be conducted either in accordance with the 1975 version of ANSI N510 or the 1980 version.
The tests should not be conducted in accordance with the 1980 version under one surveillance requirement and then under the 1975 version in another.
There are enough differences between the test procedures and the acceptance criteria of the 1975 and the 1980 N510 versions that the capability to satisfy both versions of the standard is impossible.
(4.7.2.C.1, 4.7.2.f, and 4.7.2.g) 3/4/3.7 "Monitoring Instrumentation",
P'1)
Table 3.3.7.1-1 indicates that there are to be two radiation monitors per control room intake.
There are no radiation monitors in the normal intake.
Table 3.3.7.1-1 should be corrected to reflect this.
,(2) It would appear that the radiation monitors should be operable under all operating modes.
Tables 3.3.7.1-1 and 4.3.7.1-1 should include Mode 4.
3/4.3.7.8 "Chlorine Detection System" (Removal of this technical specification in December 1986 no longer necessitates any comments.)
WNP-2 CRH SURVEY ATT 2/HAYES 07/13/87
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ATTACHMENT 3 COMMENTS ON WNP-2 PROCEDURES Based upon a review of some of the procedures for the WNP-2 control room habitability system the following comments seem appropriate.
Procedure 4.12.4.6.2 "FAZ Recovery" If fan WMA-FN-51B is operating and the control room emergency chiller CCH-CR-1B automatically starts on an F or an A signal, then it would seem appropriate for the chiller to also start on a
Z signal.
WPPSS should address this.
It would also appear appropriate for the pro-cedure to indicate that autostart of emergency chiller CCH-CR-1A occurs if WMA-FN-51A is operating.
Procedure 7.4.7.2.1 "Control Room Emergency Filtration System, "A" Operability Test" The procedure should include a test to demonstrate that when air with a relative humidity greater than or equal to 70% is encountered the heater will be actuated.
Same comment would pertain to Train B.
Alternative is for the heater to always be on when the system is actuated.
Procedure 7.4.7.2.2 "Control Room Emergency Filtration System, HEPA DOP Test".
(1)
The visual inspection described in Step C of 7.4.7.2.2.5 does not meet the technical specification requirements in that it is not done in accordance with ANSI N510-1975.
(2)
The DOP test described addresses an in-place test of the HEPA filters but does not address a system bypass test.
DOP must be injected sufficiently upstream in the system to determine whether leakage (i.e., bypass) is occurring through dampers WMA-AD-51A-1, WMA-AD-54A-2, WMA-AD-51B-1 and WMA-AD-54B-2 and must be measured at sufficient distance downstream to ensure that all potential bypass is monitored.
For example, the intake to fans WMA-FN-51A and WNP-2 CRH SURVEY ATT 3 07/13/87,
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MMA-FN-51B of the flow from the air handling units MN-AH-51A and MHA-AH-51B is an appropriate injection point to perform'tli~ bypass test.
(3)
Damper MMA-AD-51A-1 (B-1) should be closed when doing the bypas's test and fan MMA-FA-54A(B) is running.
(Step D of 7.4.7.2.2.5)
Procedure 7.4.7.2.3 "Control Room Emergency Filtration System, Carbon Adsorber Sample Test" (1)
Same comment as item 2 above for procedure 7.4.7.2.2 only for the Freon test if this procedure is really a bypass test.
If it is an in-place test it may be adequate.
(2)
A diagram should be included to show the injection ports for the Freon.
(3)
Does this procedure replace 7.4.7.2.6, "Charcoal Adsorber Bypass Leakage Test?" It does not seem that both would be necessary.
(4)
There is a damper bypass acceptance criteria of 0.05% total for all parts of the control room ventilation system.
7.4.7.2.2.6 indicates that there are no specific acceptance criteria.
WNP-2 should revise the manner in which they evaluate system bypass.
Procedure 7.4.7.2.6 "Control Room Emergency Filtration System, Carbon Adsorber Bypass Leakage Test" May not be required depending upon how procedure 7.4.7.2.3 above is utilized.
WNP-2 CRH SURVEY ATT 3 07/13/87
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