ML20235L281
| ML20235L281 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/17/1989 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-88-14, NUDOCS 8902270452 | |
| Download: ML20235L281 (13) | |
Text
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ver Valley Power Station 2
Shippingport, PA 150776 V Pres t Nudw Group M12) 6G5255 February 17, 1989 U.
S. Nuclear Regulatory Commission Attn:
Document Control-Desk Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 s
Gentlemen:
Attached is our response to the design and operations verification requested by Generic Letter 88-14,
" Instrument Air Supply System Problems Affecting Safety-Related Equipment."
This response is being submitted within 180 days of our receipt of the subject letter.
Since all of the required verifications have not been completed, our plan / schedule for completing the verifications has been provided in this response.
A subsequent submittal will be made when all actions are completed.
In the course of the design and operation verification to
- date, no components were identified which cannot accomplish their intended safety function.
If you have any questions regarding this response, please contact my office.
5 Very truly yours, h
f J.
D.
Sieber i
Vice President Nuclear Group cc:
Mr. J.
Beall, Sr. Resident Inspector Mr.
W. T.
Russell, NRC Region I Administrator Mr.
P.
Tam, Sr. Project Manager 890217 Of h((
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COMMONWEALTH OF PENNSYLVANIA)
)
SS:
COUNTY OF ALLEGHENY
)
On this
/7 day of
- 1989,
~,
HENRY G. ST0ECKER before me, a
Notary Public in and for said Commonwealth and County, personally appeared G. R.
Brandenberger, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne
- Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said company, and (3) the statements I
set forth in the Submittal are true and correct to the best of his knowledge, information and belief.
l M,
.)
NOT AR!AL SEAL HENRY 0, STOECKER, Notary PubCc Pittsburgh, Allegheny County, PA My Cornmission Expires Feb. L'O 1000
O ATTACHMENT Response to Generic Letter 88-14
" Instrument Air Sucolv System Problems Affectina Safety Related Eauipment" VERIFICATION 1 Verification by test that actual instrument air quality is consistent with the manufacturer's recommendations for individual components served.
RESPONSE
Unit 1 We have conducted an assessment of the instrument air systems at BV-1 as described in Generic Letter 88-14.
The focus of this assessment was to verify that safety-related air-operated components 'were designed and installed in accordance with their intended safety function.
This verification included a
review of system descriptions, flow
- diagrams, specifications, vendor manuals, system calculations and observation of system operation.
The review of vendor manuals and other design documentation did not identify any requirements more stringent than ISA Standard S7.3.
This standard was used to establish acceptance criteria for system operation.
The instrument air systems for the Unit 1 circulating water pump house and the Unit 2
condensate polishing system don't serve any safety related components and therefore, are not subject to GL 88-14.-
The BV-1 and BV-2 Emergency Diesel Generators' air starting subsystems start but do not control the EDG's and likewise are not considered subject to GL 88-14.
Station instrument air dew point has been tested on a weekly basis since May 1983.
The instrument air dew point prior to 1986 was approximately 10*F at atmospheric pressure.
Beginning in 1986, with increased attention and maintenance on the system, the instrument air dew point was depressed to approximately 40*F below ambient temperature.
Currently, the instrument air dew point is usually below the maximum 35'F standard set forth in ISA-S-7.3 and usually satisfied the 18'F depression requirement of ISA-S-7.3.
Station instrument air design dew point is -30*F at line pressure.
In May of
- 1986, instrument air dew point was checked at several remote locations.in the Auxiliary
- Building, Turbine Building and Water Treating Area.
No significant change in dew point was detected at the remote points in the Instrument Air System.
BVPS Unit 1 plant instrument air system was routinely tested for oil between February 1984 and December 1987.
The test was performed weekly and no oil was detected.
Routine testing for oil at BVPS 1 resumed in January 1989.
Attachment Re'sponse to GL-88-14 Page 2 Unit 1 (cont.)
Flammable / toxic chemicals are not stored nor routinely used in the vicinity of the station air compressors, therefore routine testing for flammable / toxic chemicals was not considered necessary.
BVPS Unit 1
will verify by test, with a portable H2/02 gas survey meter that the instrument air is free of flammable chemicals starting February 1, 1989 and weekly thereafter.
The instrument air system at Unit 1 was not routinely tested for dirt.
The system has several air filters, one at the inlet of each air compressor and one at the inlet and outlet of the instrument air dryer.
The prefilter for the instrument air dryer is 0.1 microns, thus providing air cleanliness far in excess of ISA-S-7.3 to the instrument air dryer.
We will test the air cleanliness at the outlet of the instrument air receiver for compliance with ISA-S-7.3 starting February 16, 1989.
The instrument air system at BVPS 1 downstream of the air receiver is made of copper and stainless steel pipe.
The air receivers are made of carbon steel as is some of the piping upstream of the air receiver.
The air filters and dryer are also located upstream of the air receiver.
The containment instrument air system was not routinely tested.
A procedure will be generated to test for dirt, oil, flammable gases and dew point.
Since the containment instrument air system is inside containment, testing will be performed during refueling outages and will begin during the next refueling outage scheduled for September 1989.
The flammable gases check will be performed using a portable H2/02 survey meter.
The. Intake Structure instrument air system was not routinely tested for
- dewpoint, oil, dirt or flammable chemicals in the past.
Testing of the system for these parameters / contaminants will commence in February 1989.
The Control Room Ventilation System instrument air system was not routinely tested for dewpoint, oil, dirt or flammable chemicals in the past.
Testing of the system will commence following the installation of a
sample location in the system.
It is anticipated that the sample location will be installed by the time Unit 1
starts up from the refueling outage scheduled to start September 1989.
Unit 2 We have conducted an assessment of the instrument air systems at BV-2 as described in Generic Letter 88-14.
The focus of this assessment was to verify that safety-related air-operated components were designed and installed in accordance with their intended safety function.
This verification included a
review of system descriptions, flow
- diagrams, specifications, vendor
- manuals, and system calculations.
In the case where vendor manuals did not stipulate an acceptance criteria for air quality, compliance with standard ISA S7.3 and NUREG 0800 was considered adequate.
Attachment Response to GL-88-14 Page 3 Unit 2 (cont.)
The plant instrument air dewpoint has been tested on a weekly basis since
- October, 1987.
The instrument air dewpoint has not met the systems' design dewpoint of -30*F at line pressure.
The dewpoint has occasionally met the 35'F at line pressure requirement called for in ISA-S7-3 but has not met the more stringent value of 18'F below ambient temperature at line pressure also called for in ISA-S7.3.
The BVPS Unit 2
plant instrument air system was not routinely tested for oil, dirt and flammable / toxic gases since the station air compressors are an oil free design and flammable / toxic chemicals are not stored in the vicinity of the station air compressors.
Since flammable / toxic chemicals are not stored or routinely used in the vicinity of the station air compressors, routine testing for flammable / toxic gases was not considered necessary.
The instrument air system at BVPS 2
is made of copper and stainless steel pipe downstream of the air receiver.
The system's air receivers are, however, made from carbon steel.
Air filters are installed upstream and downstream of the air dryer.
These filters are 3
microns or finer.
In addition, the upstream filter will be replaced at the March 1989 refueling outage with a
0.1 micron filter.
The air filters and dryer are currently located upstream of the carbon steel air receiver.
The procedure was revised to incorporate routine testing for oil, dirt and flammable gases.
Routine testing for these contaminants will begin February 1989.
A portable H2/02 gas survey meter will be used for the flammable gas check.
The containment instrument air dewpoint was not routinely tested in the past.
The containment instrument air dewpoint will be routinely monitored using the skid mounted dewpoint indicator on the containment instrument air dryer
[2IAC-DRY 21]
starting in January 1989.
A procedure to test the containment instrument air for oil, dirt and flammable gases will be preparad and implemented in July 1989.
A portable H2/02 gas survey meter will be used for the flammable gases check.
l
[
f Attnchment Re'sponse to GL-88-14 Page 4 VERIFICATION 2 Verification that maintenance practices, emergency procedures, and training are adequate to ensure that safety-related equipment will function as intended on loss of instrument air.
RESPONSE
Unit 1 and Unit 2 The Institute of Nuclear Power Operations issued Significant Operating Experience Report (SOER) 88-1,
" Instrument Air System Failures" on May 18, 1988.
The SOER 88-1 recommendations and the Station's responses or summary of their responses which follow below address the above verification.
SOER 88-1 OPERATIONS RECOMMENDATIONS:
1.
Provide procedures to assist operators in the identification,
- control, and recovery from partial or total loss of instrument air event.
Operating, abnormal, and emergency procedures should provide the following:
indications of loss of instrument
- air, i.e.,
- alarms,
+
automatic actions, functions lost, etc.
identification of critical components operated by instrument air and the position in which they fail.
expected system and plant responses to a loss of instrument
+
air and the consequences of these responses.
actions to take if critical components do not fail in the i
intended position.
manual actions the operator should be expected to take to
+
respond to a loss of instrument air event.
restoration actions to be taken after instrument air is regained.
SOER 88-1 Operations Response 1:
The Unit 1
and 2 normal operating procedures for the instrument air system were not reviewed because a
partial or total loss of instrument air would cause the operators to enter the Abnormal Operating Procedures to determine the appropriate actions.
Unit 1 AOP 1.34.1 lists the
- alarms, functions lost, critical components operated by instrument air and the position in which they fail, the expected system and plant responses to a loss of instrument air and the consequences, the actions the operators should take, and provides direction to the operator in the event instrument air is restored.
Attachment Response to GL-88-14 Page 5-SOER 88-1 Operations Response 1 (cont.)
Unit 2
AOP 2.34.1 has similar instructions.in the procedure for the operators.
This recommendation is. currently being complied with, with regards to the Abnormal Operating Procedures.
These Abnormal Operating Procedures are in the process of being changed into alarm response procedures which will contain the same guidance as the AOP's.
The following procedures were identified as also providing guidance to the operators during IAS abnormal events.:
O.M.
1.34.4.F,
" Cross-connecting the Instrument Air System,"
provides instructions at Unit 1 to provide the containment air system with instrument air from outside containment.
It is used only in emergencies because opening [1IA-90]' enters a Technical Specification action statement.
O.M.
1.34.4.J,
" Emergency Nitrogen Supply as a Media To Operate Penetration Area Valves,"
provides a
method at Unit 1
of operating air operated valves in the outside containment penetration area during a
loss of instrument'
- air, by connecting a nitrogen bottle and pressure regulator to the isolated instrument air line.
O.M.
1.34.4.L,
" Placing the Diesel Air Compressor in Service,"
starts a
diesel air compressor at Unit 1 and aligns it to the ir.strument. air system as an emergency source.
O.M.
2.34.4.C,
" Cross-connecting the Station Air System and Instrument Air System with Other Air Systems,"
cross-connects the Unit 2
station air system to the condensate po!n.hing air
- system, and in Modes 5 and 6, supplies containment instrument air from the station air system.
We have reviewed these procedures and found them to be complete.
SOER 88-1 TRAINING RECOMMENDATION:
Trainina 2.
Provide classroom and simulator training on loss of instrument air event to operators.
This training should provide the bases for such things as failure modes of critical components and expected operator
- action, so that operators will understand the major concerns involved in a
loss of instrument air event.
Simulator training should illustrate such items as the following:
transients initiated by a
partial or total loss of instrument air.
\\
w
. Attachment.
l L
Response to GL-88-14 L
Page 6 Trainina (cont.)
abnormal complications that can be anticipated to occur from
+
the failure of critical components to function as intended after a loss of instrument air.
indications of a loss of instrument air.
+
3.
Provide training on the importance of instrument air systems and the potential for common mode failures caused by such things as particulate, hydrocarbon, and water contamination for operators and maintenance personnel who work on air systems and air-operating components.
SOER 88-1 Trainina Response 2 &1 SOER 88-1
" Instrument Air System Failures" has been reviewed by the Operations Training Section.
The following initial and-retraining programs / lesson' plans will be reviewed and revised to insure the specific concerns of this report are addressed.
License retraining classroom Module 4 88/89 cycle
-(By Feb. 20, 1989)
License Retraining Simulator Module 3/4 88/89 cycle (By Feb. 20, 1989)
Non-License Retraining Module 3 88/89 cycle (complete by Feb. 17, 1989)
Initial Operator. Training (Prior to next presentation, no trainees in training)
Simulator LP-SQS-34.1 2LP-SQS-34.1 Initial STA Training (Prior to next presentation, no trainees in training)
LP-STA-54A NOTE:
STA retraining covered as STA's participate in license retraining.
Technical Personnel Training LP-TPT-20 (initial training) (By 3/31/88)
LP-TPT-100B (retraining)
(completed)
It should be noted that the Loss of Instrument Air / Instrument Air System Failures has always been included as a part of the Operator Initial and Retraining programs.
l L
Attachment I
1 Response to GL-88-14 L
- Page 7' SOER 88-1 Maintenance Recommendations 4.
Periodically monitor air quality at several points throughout the instrument air
- system, system air quality, as measured at the l
discharge of the air dryers and after -filters, should be l
maintained within the requirements of ANSI Standard ISA-S7.3.
l Air quality at the inlet supply to safety-related and critical components needed to shutdown and maintain the plant in a safe condition should be maintained within the specifications of i
equipment vendors.
If air quality is not maintained within these specifications, take action to-Improve the air quality (e.g.,
replace filters or desiccant; blowdown affected portions of the system; install filters upstream and in close proximity to components that have had a chronic problem with a contaminated air supply),
and perform inspections to ensure the continued R
operability of equipment exposed to these conditions.
5.
Ensure the station's preventive maintenance program provides for replacing filters and desiccant
- material, and performing air dryer maintenance on a regularly scheduled basis.
The frequency of this preventive maintenance should be based on vendor recommendations, previous equipment operating
- history, and an ongoing monitoring program of important instrument air parameters including air
- quality, filter differential pressures, and air dryer performance.
SOER 88-1 Maintenance Responses 4 and 5 (
SUMMARY
)
A review was performed of the existing surveillance programs and preventive maintenance programs for the instrument air systems for I
both Units 1
and 2.
As a result of this review we have concluded that the surveillance and preventive maintenance activities along j
with the operational testing activities are sufficient to ensure proper operation of these systems and components.
1
,l 1
a wn--_._----_
Attachment Response to GL-88-14 Page 8 VERIFICATION 3 Verification that the design of the entire instrument air system including air or other pneumatic accumulators is in accordance with its intended functions, including verification by test that air-operated safety-related components will perform as expected in accordance with all design-basis
- events, including a loss of the normal instrument air system.
This design verification should include an analysis of current air operated components failure positions to verify that they are correct for assuring required safety functions.
RESPONSE
Unit 1 Failure modes of safety related air operated valves have been
- verified, the UFSAR description was reviewed, and the total system design was studied with respect to improving the reliability of the system.
Engineering changes to enhance the reliability of the system are under further review.
The review did not disclose any incorrect failure position for air operated safety-related valves.
A gradual loss of instrument air test was performed at Beaver Valley Unit I
on or about March 11, 1975.
All Q.A. Category I air operated valves associated with the Engineered Safety Features were tested for proper failure position by BVT 1.1 - 10.34.1, " Response of Plant Air Operated Valves to Loss of Instrument Air".
Ninety-six Q.A.
Category I
air operated valves were not tested.
These valves are being reviewed to determine if any of these valves require testing to satisfy Generic Letter 88-14.
Any such valves which have not been tested will have a procedure (s) prepared and will be tested to verify proper failure position during the refueling outage which begins September 1989.
We reviewed the design of safety-related air or pneumatic accumulators to ensure the accumulators are properly sized and seismically supported as necessary.
The accumulators that were reviewed are associated with the Feedwater Bypass Valves [FCV-FW479, 489 499],
the Control Room Air Pressurization System sealing bladders for the Control Room Outside Air Intake and Exhaust Dampers
[VS-D-40-1A,1B,1C&lD]
and the Reactor Coolant System Pressurizer Power Operated Relief Valves
[PCV-RC455C&D]
associated with the Reactor Vessel Cold Overpressure Protection.
No inadequacies were discovered.
The N
accumulators for the PORV's, that are used as 2
part of the reactor vessel overpressure protection system, were tested for proper operation as part of the design change package installation program.
Unit 2 We have conducted an assessment of the instrument air systems at BV-2 as described in Generic Letter 68-14.
The focus of this assessment
L Attachment Re'sponse to GL-88-14 Page 9 Unit 2 (cont.)
was to verify that safety-related air-operated components were designed and installed in accordance with their intended safety function.
This verification included a
review of system descriptions, flow
- diagrams, specifications, vendor
- manuals, and system calculations.
Failure modes of safety related air operated valves were verified; the UFSAR description was
- reviewed, and
- finally, the total system design was studied with respect to improving the reliability of the system.
We will review changes and modifications to enhance the reliability of the system.
The review did not disclose any incorrect failure position for air operated l
safety-related valves.
A gradual loss of instrument air test was performed at Beaver Valley Unit II on December 11, 1986.
All but 2 Q.A. Category I air operated valves that are connected to the instrument air system were tested for proper failure position on loss of air by SOV 2.34.05, " Response of Plant Air-Operated Valves to Loss of Instrument Air".
The two outstanding
- valves, 2CHS*HCV244 and 2SSR*AOV101C, were tested for proper failure position on loss of air during Phase I Testing by ITP-108, " Testing of AOV's and Dampers".
Containment instrument air receiver capacity was verified by test in SOV 2.34.04,
" Containment Instrument Air Design Verification Test",
on July 20, 1987.
The air system is not safety-related and the l
receiver is sized and intended to allow air operated components to I
ride out minor or short term loss of the containment air system air compressors such as occurs during a Containment Isolation Phase A (CIA).
We performed a
review of the accumulators associated with the BV-2 Feedwater Isolation Trip Valves
[2FWS*HYV157A, B
and C) and the accumulators associated with the Main Steam Isolation Valves (2 MSS *HYV101A, B
C)
This review did not reveal any inadequacy in sizing or seismic support for the accumulators.
Attachmant Response to GL-88-14 Page 10 REOUESTED ADDITIONAL INFORMATION In addition to the above, each licensee / applicant should provide a discussion of their program for maintaining proper instrument air quality.
RESPONSE
Our program to assure maintenance of instrument air quality has been discussed previously.
To summarize, it includes the following:
Onerations operation of the instrument air systems is conducted using formally prepared and approved operating procedures.
These procedures control operation of the system components such as placing the standby compressors in
- service, placing the air dryer bypass filters in service, and similar type manipulations of the system components.
Unit
- 1 Abnormal Operating Procedures (AOP 1.34.1) lists the alarms, functions
- lost, critical components operated by instrument air and the position in which they
- fail, the expected system and plant responses to a
loss of instrument air and the consequences, the actions the operators should
- take, and provides direction to the operator in the event instrument air is restored.
Unit #2 has similar Abnormal Operating Procedures (AOP 2.34.1) which are in the process of being changed to alarm response procedures.
Operations also takes an active role in maintaining instrument air system quality.
Operations personnel observe air dryer operation as well as perform periodic blowdowns of the instrument air system.
The pressure drop across the system filters is monitored to detect filter clogging.
Testina Testing and Plant Performance Group personnel perform routine tests on the air systems such as dewpoint
- tests, checks for oil or flammable gas in the air and checks for particulate in the air.
If conditions adverse to quality are discovered, they are reported to the on-duty Nuclear Shift Supervisor.
Testing and Plant Performance Group personnel also perform capacity checks of the air compressor and observe the air dryer absorption and regeneration cycles periodically to assure reactivation cycle timers are set properly.
Maintenance Work Requests are generated to obtain maintenance support to correct system problems.
Maintenance The maintenance of the instrument air system helps ensure the quality of the air.
Formally approved procedures are used for preventative i
m-_ _ _ _ _ _ _ _. _.----.---- - - - - - - - - - -. - _. _ - - - - - - - - - - - - - - - - - - - - - - - - - - -
Attachment Response.'to GL-88-14 Page 11 maintenance tasks.
The types and frequency of the preventive-maintenance tasks address.the equipment vendor recommendations and/or-the previous
-experience.of Duquesne Light. Company maintenance personnel with similar equipment and applications.
.The. repair of equipment is performed using site approved procedures prepared in accordance with the guidance from the applicable vendors instruction manuals.
- _ - _ - _ _ _