ML20100C335
| ML20100C335 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 03/27/1985 |
| From: | Mittl R Public Service Enterprise Group |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| TASK-2.K.3.28, TASK-TM NUDOCS 8503290004 | |
| Download: ML20100C335 (17) | |
Text
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9 O PSEGiEF-80 Park Plaza, Newark, NJ 07101/ 201430-8217 MAILING ADDRESS / P.O. Box 570, Newark, NJ 07101 Robert L. Mitti General Manager Nuclear Assurance and Regulation March 27, 1985 Director of Nuclear Reactor Regulation U.S.
Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814 Attention:
Mr. Albert Schwencer, Chief Licensing Branch 2 Division of Licensing Gentlemen:
REQUEST FOR ADDITIONAL INFORMATION TMI ITEM II.K.3.28 HOPE CREEK GENERATING STATION DOCKET NO. 50-354 As requested in a letter from A.
Schwencer to R.
L.
- Mitti, dated January 25, 1985, attached is the additional informa-tion on TMI Action Item II.K.3.28, Qualification of Accumu-lators on Automatic Depressurization System Valves.
Should you have any questions in this regard, please contact us.
Very truly yours,
$!,sl f
i 8503290004 850327 PDR ADOCK 05000354 Attachment A
PDR C
D.
H. Wagner USNRC Licensing Project Manager (w/a t ta ch. )
A.
R.
Blough USNRC Senior Resident Inspector (w/ attach.)
o\\
The Energy People II 95 431214V) 7 81
REQUEST FOR ADDITIONAL INFORMATION Hope Creek Generating Station MULTI-PLANT ACTION F-55 OR TMI II.K.3.28 VERIFY QUALIFICATION OF ACCUMULATOR ON ADS VALVES Question 1)
Based on the requirements of NUREG-0737 Item II.K.3.28, it is necessary to demonstrate that the ADS valve s, ac cumula to rs, and associated equipment and instru-mentation meet the requirements specified in the pla n t FS AR and are capable of performing their functions during and following exposure to hostile environments, taking no credit for non-safety-related equipment or i ns t ru me nta tion.
Additionally, air (or nitrogen) leakage through the valves must be accounted for to assure that enough inventory of compressed gas is available to cycle the ADS valves.
If this cannot be demonstrated, it must be s hown tha t the accumulator de sign is still acceptable.
Since this system is a pa rt of the emergency core cooling system, it must still perform its function for the long-term period of 100 days following an accident.
You are requested to address in detail (a) how you meet this long-term capability requirement of 100 days following an accident or (b) the justification as to why a shorter time frame is suf ficient long-te rm capability for your plant, or (c) provide a commitment and schedule for upgrading to the 100 day long-te rm capability requirement.
Response 1)
The design of the Hope Creek Generating Station is such that the ADS will be available for 100 days following an accident.
During the time immediately following an accident, gas is available to actuate each ADS valve from its own local accumulator.
At appro ximately 20 minutes into an accident period, the ADS accumulators are reconnected to the primary containment i ns t rumen t gas system, described in Section 9.3.6 of the HCGS FSAR, which assures the availability of the compressed gas for 100 day operation.
Controls, instrumentation, valves and equipment required for operation of the ADS, are environmentally and seismically qualified for their f unction and location in the plant.
See the following FSAR sections for further information:
Question 1 - page 1 of 2
I
[
l 3.9
- Seismic qualification 3.10 - Seismic qualification 3.11 - Environmental qualification 5.2
- Main steam sa fe ty-relief valves 6.3
- Emergency core cooling systems (including ADS in Se ction 6.3. 2. 2.2) 7.3
- Engineered safety feature systems controls (including ADS in Section 7.3.1.1.1.2) 3 9.3.6
- Primary containment instrument gas system l
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i Question 1 - Page 2 of 2 i
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j Question 2)
Define the number of times the ADS pneumatically controlled valve is capable of cycling using only the accumulator inventory at atmospheric pressure and at a specified percent (i.e., 70%)
of drywell pressure, and the length of time these accumulators are capable of pe rforming their function following an accident.
Res ponse 2 )
The Hope Creek SRV accumulators are capable of providing the following number of SRV actuations prior to draining below the pressure required i
to operate the SRV's:
a) 64 cycles at O psig drywell pressure b) 17 cycles at 43.8 psig, 70% of drywell design pressure With pneumatic system makeup capability equal to or greater than 1 SCFH per SRV, to account fo r S RV actuator leakage, cycling of the SRV's is not limited by the pneumatic system.
Should the makeup air system fail, each accumulator is capable of pro-viding at least one SRV operation up to 1.2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following the loss of the makeup system, with less than or equal to 1 SCFH pneumatic leakage.
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Question 2 - Page 1 of 1 4
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Question 3)
Describe the ADS accumulator system design and operation (e.g., trains, air supply, capacity, alarms and instrumentation and their location, e tc. )
Response 3)
As is typical for all of HCGS' SRVs, each ADS valve is provided with a local accumulator to provide a dedicated source of compressed gas for actuation.
These accumulators have a capacity of 10 gallons and are located in the drywell.
The ADS is shown schematically on FSAR Figure 5.1-3, Sheet 1.
The Primary Containment Instrument Gas System (PCIGS),
described in FSAR Section 9.3.6, provides the source of supply for the accumulators.
During normal oper-ation, the two PCIGS heade rs are interconnected to provide compressed gas to all PCIGS users.
During a post-DBE period, the PCIGS headers are isolated fr om each other; one of the headers supplies three of the ADS valves, while the other header supplies the re-maining two ADS valves.
Each of the redundant PCIGS trains consists of a compressor, coolers, drye rs,,
instrumentation and receiver tank as shown on FSAR Fig ure 9. 3-11.
The PCIGS compressor trains and re-ceiver tanks are located at elevation 132 feet in the reactor building.
Each receiver tank has a volume of 225 cubic feet and cycles between 90 and 105 psig.
Press ure switches located on the receivers control the compressor cycling to maintain receiver pressure.
High-high and low-low receiver pressure is annunciated in the main control room to alert the operator to pro-blems at the rece iver.
Each compressor train has a nominal capacity of 20 scfm at the dryer outlet.
Question 3 - Page 1 of 1
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Question 4)
Define the basis for the allowable leakage criteria for the ADS accumulator system (e.g., boundary conditions, environmental and seimic parameters, opera tor inte rface, ma rgi n, e tc. ).
Response 4)
The allowable leakage criterion of 1 SCFH per SRV is to assure adequate accumulator capacity for 1 SRV actuation for a period of one hour, following an intermediate or small break, without re cha rgi ng the accumulator.
The accumulator has suf ficient capa ci ty to pe rmit 1 SRV actuation against a drywell pressure of 43.3 psig, well above any drywell pres-sure produced by an intermediate sized break re-quiring ADS.
Question 4 - Page 1 of 1
Question 5)
What margin is in the allowable leakage criteria to account for possible increase in le a kage in the ADS accumulator system resulting from ef fects of a harsh environment and/or a seismic event?
Res ponse 5)
General Electric's experience from previous environ-mental qualification and ongoing NUREG-0588 tests simulating harsh and seismic environments shows that for well beyond the assumed 1 nour period, SRV penumatic leakage will not exceed
.5 SCFH.
This assures that the leakage rate does not ex-ceed 1 SCFH following an accident, with signifi-can t ma rgin.
i Question 5 - Page 1 of 1
Question 6)
A statement that test and/or analysis performed verified that a ha rsh environment and/or seismic event would not increase the leakage rate in the ADS ac cumula tor system.
Response 6)
The in progress NUREG-0588 SRV test shall verify that the SRV actua tor pneumatic leakage will not exceed the allowable for up to 100 days in the DBE environment (LOCA + pos t-LOC A) followi ng radiation, thermal, operational, vibrational and seismic ( 5 OBE and 1 SSE) aging.
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Question 6 - Page 1 of 1
Question.7)
A statement that verifies that no credit was taken for non-sa fe ty-re lated equipment and instrumentation when establishing the allowable leakage criteria for the ADS accumulator system.
Response 7)
When' establishing the allowable leakage criteria for the ADS accumulator system, no credit fo r non-sa fety-related equipment was taken.
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Question 7 - Page 1 of 1
Question 8)
Provide a concise description of the tes ts perf ormed on the ADS accumulator system, and backup, and their frequency.
Response 8)
The piping and valves associated with the ADS accumulator subsystem are periodically tested to ensure proper operation.
The scope and frequency of testing is as described below:
The check valves in the ADS accumulator sub-system are tested in accordance with the re-quirements of ASME Section XI Subsection IWV,
" Inservice Testing of Valves in Nuclear Power Plants."
The check valves are exercised to the position required to fulfill their func-l ti on in order to demonstrate their operational readiness.
Tes ts are conducted to demonstrate that the check valves open on reversal of pressure differential as evidenced by disc movement when flow through the valve is init-iated.
Additionally, the valves are tested to demonstrate that the valve disc travels to the seat promptly on cessation or reversal of flow.
Confirmation of disc movement is ob-tained through observation of appropriate pressure indictions in the system.
The fre-quency of check valve testing is in accordance with Inservice Test Program Requirments.
A relief valve protects each ADS accumulator subsystem for overpressurization.
Like the check valves mentioned above, the relief valves are periodically tested in accordance with the requirements of ASME Section XI Sub-section IWV to demonstrate operational read-iness.
Tests are conducted to verify the re-lief valve setpoint.
Tests are conducted such that all valves are tested every 5 years.
The piping in the ADS accumulator subsystem is ASME Class 3 and periodically pressure tested in accordance with the requirements of ASME Section XI Subsection IWD.
Tests are con-ducted during each of the inspection intervals specified in Subsection IWA for the service lifetime of the plant.
Question 8 - Page 1 of 1
Question 9)
Provide a concise description of the surveillance pe r fo rmed, and how fr eq ue n t, on alarms and instru-mentation associated with the ADS accumulator system and backup system.
Response 9)
Per the draft technical specifications attached with the response to Question 13, the following surveillance testing is performed:
a)
At least once per 31 days, a channel functional test of the primary con-tainment instrument gas system low-low pressure alarm is performed.
b)
At least once per 18 months a channel calibration of the primary containment instrument gas system low-low pressure alarm is performed.
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i Question 9 - Page 1 of 1 L.
Question 10)
Provide a statement that confirms that the ADS accumulator system, backup system, and asso-ciated equipment and control circuitry, are seismically qualified.
Res po nse 10)
The ADS accumulator system, backup system, and associated equipment and control circuitry are seismically qualified.
Seismic qualification is discussed in FSAR Sections 3.9 and 3.10.
l Question 10 - Page 1 of 1 t
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Question 11)
Provide a statement that confirms that the Aos accumula tor system, backup system, and associated equipment and control circuitry are environmental-ly qualified for conditions associated with normal operation, maintenance, testing, and postula ted acc ide nt s.
Response 11)
The ADS accumulator system, backup system, and as-sociated equipment and control circuitry located in a harsh environment are environmentally qualified for the conditions postulated to exist at their locations.
The conditions that the equipment will experience and an overall discussion of environmental qualification may be found in FSAR Seaction 3.11.
Question 11 - Page 1 of 1
Question 12)
Provide a statement verifying that the ADS valves, ac cum ula to rs, backup system, associated equipment and instrumentation are capable of performing their f unction during and following an accident situation while taking no credit for non-safety related equipment and instrumentation.
Res po nse 12)
The ADS valves, a ccumula to rs, backup system, associated equipment and instrumentation are capable of pe rforming their function during and following an accident situation without relying on non-safety-related equipment and instrumentation.
All components necessary for operability of the ADS are safety-related and are environmentally as well as seismically qualified, as discussed in Responses 11 and 10, res pe ct ively.
Question 12 - Page 1 of 1
Question 13)
Excerpts fron the plants technical specif ica-tion verifying that they specify the following:
- ADS leak test frequency
- Allowable leakage rate
- Actions to be taken, in a specified time f rame, should the leakage rate be exceeded.
Response 13)
Though, there are no Technical Specification requirements for leak testing the ADS accumu-lator and backp system, the ADS accumulator check valves are included in the Inservice-Test Program to be functionally tested and re-verse flow check tested during shutdown if three months has elapsed since the last test.
HCGS Draft Technical Specification Section 3/4.5.1 ECCS-Operating, Surveillance Require-ment 4.5.1d (attached) provides requirements for a channel functional test of the Primary Containment Instrument Gas System low-low pressure alarm system at least once per 31 days and a channel calibration at least once per 18 months.
GR01 1/2 Question 13 - Page 1 of 2
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EMEsGENCY CORE C00 LING SYSTEMS v
SU*v!!t. LANCE RiDU!REMENTS (Continued) 2.
For the NPCI system, verifying that:
The system develops a f'pt of at least 46000F gpa against a a) test line pres'_sure ofJ9 psig, ::::::::-d' ;;
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E A15, fig.**when steas ' M E N s W The suction is automatically transferred from the condensata b) storage tank to the suppression chamber en a condensate torage tank water level - low signal and on a suppression
- water 1 high signal, c
l For the A05:.
At least once per 31 days, performing a CHANNEL ONAL TEST d.
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of the tr-
" "- 5 "7 :, ::*:r*Aas system 1 saure alarm system.
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At lea'st onc's per 18 months:
Per.f.gtning a system functional test which includes l
a)..
simulated. automatic actuation of the system throughout its emergency operating sequence, but excluding actual valve actuation.
Manually opening each AOS valve when the reactor staam b) does pressure is greater than or equal to 100 psig(**) and observing that either:
- 1) -The control valve or typass valve position responds l
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accordingly, or 2)
There is a corresponding change in tha sessured steam l
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c)
Performing a CHANNEL CAL RATION of thep?-
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- r:r::r M gas system 1 essure alarm system and verifying an alarm setpoint of {Sf) + -JS} psig on decreasing pressure.
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""The provistons of Specification 4.0.4 are not applicable p l.
adequate to perform the test.
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Question 13 - Page 2 of 2
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Question 14)
Provide a concise description of the design and operation of the backup system and confirm that it will meet the overall requirement of the ADS system following an accident.
Response 14)
The primary containment instrument gas system
( P CCGS) provides the backup to the ADS accumu-lators and is discussed in FS AR Section 9.3.6.
During the post-accident pe riod, the PCIGS will cycle to maintain the instrument gas receiver be tween 90 and 105 psig and has a nominal capacity of 20 scfm.
The portions of the PCIGS that are required to supply the ADS accumulators are clas-sified safety-related, seismic Category I, and are seismically and environmentally qualified.
Power is provided by a Class 1E power supply with the Class lE standby electrical supply as a back-up.
The capacity of the PCIGS is adequate to supply the ADS following an accident.
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Question 14 - Page 1 of 1 4
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