ML19326C809
| ML19326C809 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/02/1973 |
| From: | Bernero R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8004280741 | |
| Download: ML19326C809 (8) | |
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UNITED STATES D_q _ -sq
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ATOMIC ENERGY COMMISSION 6*
l W ASHINGTON, D.C.
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e,re s e FE8 2 1973 Docket No. 50-313 R. C. DeYoung, Assistant Director for Pressurized Water Reactors, L THRU:
A. Schwencer, Chief, Pressurized Water Reactors Branch No. 4, L MEETING WITH ARKANSAS POWER AND LIGHT COMPANY BABCCCK & WILCOX AND BECHTEL, CONCERNING REVIEW OF THE OPERATING LICENSE APPLICATION FOR UNIT 1 ARKANSAS NUCLEAR ONE Enclosed is a report of the meeting held on January 23, 1973 with Arkansas Power and Light Company. The attendance list is also enclosed.
A R. M. Bernero, Project Manager Pressurized Water Reactors Branch No. 4 Directorate of Licensing
Enclosures:
1.
Meeting Report 2.
Attendance List cc: RSBoyd DSkovholt DKnuth RMaccary RTedesco HDenton PWR Branch Chiefs RWKlecker MRosen R0 (3)
8004280 7N
4 ENCIDSURE '.
/AKANSAS POWER AND' LIGHT COMPANY ARKANSAS NUCLEAR ONE-UNIT 1 DOCKET NO. 50-313 REPORT OF PdETING - JANUARY 23, 1973 Sumary he meeting was held to discuss the outstanding inquiry on in-situ testing
.of active valves and to present to the applicant the results of the staff's electrical and control safety evaluation.
'ihe applicant was given some guidance on how he might respond to the December 27, 1972,. inquiry on active valves. Arkansas Power and Light Company (AP&L) agreed to consider the saidance given and notify the Project Manager as soon as possible of the scope and schedule of their response.
The principal conclusions of the electrical and control safety evaluation were enumerated to'AP&L. All of the safety concerns involved were pre-viously lawn to the applicant. R e status of resolution of outstanding items was reviewed.
Valves h e applicant and his contractors first explained the practices that are being followed for the procurement and test of valves. Certain valves are prequalified and all the active valves must meet the Class I code (Arkansas 1 FSAR terminology). 'Ihe valves are typically mounted and snubbed so that the top works are subjected to no more than 3g acceleration in any direction and the minimum frequency is 20 Hz. Se valves themselves are built to ASME code and some operators, such as Limitorque, have U. S.
Navy specifications and tests.
We installed tests of valves were sumarized using the Decay Heat Removal System (DHRS) as an example. We sequence of tests enumerated was:
1.
DHRS Electrical Test (" unloaded" operation)
- 2..DHRS Hydrostatic Test-3 DHRS Functional Test (flow, pressure drop, etc.)
4.
DHRS Engineered Safeguards Test (functional) 5 Integrated Engineered Safeguards h st 6.
Technical Specification Surveillance Tests i
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2e AEC staff then comented on the matter. S e valve problems that have been found in operating plants are the cause. of the AEC's concern. It was emphasized that the concern here is about the operability of valves, not about valve body integrity. Se staff concern is with safety related active valves, namely those which must operate (in the words of the FSAR guide):
1.. to prevent or mitigate the consequences of accidents and malfbnctions originating within the reactor coolant pressure
- boundary, 2.
to pemit shutdown of the reactor and maintenance in the safe shutdown conditicn, and 3
to contain radioactive material.
Se generic nature of this question was acknowledged and AP&L was assured that the staff was not trying to bunien them alone with its resolution.
AP&L was told that the staff expects any practical test program to reflect plant-to-plant prototypeness and not to test every valve.
Bere was some discussion of in-situ test methods where a relatively small exciter is mounted on the component of interest.
AP&L was asked to provide a systemized tabulation of all Category I systems' active valves, giving related system conditions, predicted seismic response and how conditions have been met or would be met by test. AP&L should' con-sider additional testing to simulate seismic excitation and appropriate plant conditions, at; least of active valves in the reactor coolant pressure boundary. S e staff indicated to AP&L that it might be acceptable to cover all' active valves on a schedule extending past the Ibel loading date.
AP&L' agreed to confer with their contractors and notify the AEC promptly of the proposed scope and schedule of their response.
Electrical and-Control Review he results of the electrical and control safety review were surmarized to AP&L by the following list of 18 items:
1.
Reactor Protective System (RPS): h e Reactor Building pressure sensors are analog; the drawings call for digital units. AP&L should detemine which is proper and correct acconiingly.
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- 2.
Primary Makeun Pumps: 'Ihe thini makeup pump is set up as an installed spare for automa'ic start if the parallel co@ anion does not start. Based on current emergency loads for.the diesel generator, the extra 700 H.P. load that would be imposed if both punps were to start by mistake is con-sidered excessive and might cause the loss of the diesel
. generator. AP&L has.the choice of incorporating appropriate tests of the-time delay relay circuit in the Technical Specifications-or modifying the design to have the extra punp on manual start only.
3 Engineered Safeguards Actuation System:
A number of cmissions and errors have been identified related to the zwactor building and penetration room. ventilation systems. 'Ihese were pointed out in preceding drawing review meetings; AP&L must correct these.
- 4. - Air-Operated Valves: 'Ibe design philosophy for air-operated valves was questioned during the review. AP&L has recently con-firmed the design approach that loss of air puts cafety related air-operated valves in the safeguards position. AP&L must ecm-plete a: review of all air % perated valves to confirm that they conform.
5 Valve 'Ibraue Switch Interlocks: Because the torque switch is by-passed only during the first portion of valve travel, AP&L should evaluate and' consider valve tests with momentaryloss of power to demonstrate that valvea stopped at mid travel will ccuplete their strokes.
6..
Decay Heat Removal System (DHRS) Valve Interlocks: During the design review the AEC staff furnished AP&L the control require-ments for the valves isolating the low pressure portions of the DHRS. AP&L must redesign.the controls for these valves and furnish the details to the-AEC.
7.-
Core Flooding Tank CFT)-Isolation Valves:
AP&L Ehould modify the control system of the CFT isolation valves as indicated during the review meetings.
- 8. - Lubricating Oil for Engineered Safeguanis Pumps:
If the pu:: ping and cooling of the lubricating oil is essential for these pumps (injection and spray punps), then the associated instrument and
. control systems must meet the objectives of IEEE-279
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9 Safety Related Switch; rear Room Coolers: Since the coolers for both rooms derive power from the. same source, AP&L must analyze to determine the results of the single failure of this power source.
- 10. Reactor Ccolant Pressure Transmitters: Rese transmitters effect a reactor coolant pressure reactor trip on a 2-out-of-3 basis; two of then are mounted on the same instrurent rack in the Reactor Building. Assuming a co:::rm mode failure disabling these
-two transmitters, AP&L should demonstrate the acceptability of this arrangement on the basis that diverse instrumentation pro-vides equal protection, or these pressure sensors should be separated.
- 11. Diesel Generator Room Door:
AP&L should demonstrate the ad q uacy of the door between the diesel generator rooms to prevent simultaneous flooding of both diesel generator roms.
- 12. Battery Boom Ventilation: AP&L should show that the ventilation duct connecting the two battery rows does not violate separation criteria or change the design.
13 Feedwater Control System: he safety significance of the feedwater and emergency feedwater control systems remains to be resolved.
111 Underfloor Cables in Control and Computer Rooms: AP&L should demonstrate the adequacy of these cable installations to withstand all design basis events (fire, flood, etc.).
15 Overhead Cables in Control Room: AP&L should provide a fire barrier between these cables and the Control Roam as well as a suitable fire suppression system for these cables.
- 16. Control Room Package Coolers: AP&L should evaluate the failuru mechanisms of these coolers and their effect on adjacent safety related equ11 rant.
' 17 Use of Diesel Generators for Peaking Service: 'Ihe use of emergency diesel generators for peaking service shall not be permitted because it co:: promises' the independence of emergency power sources.
- 18. Offsite Power Connection: 'Ihe interlock schemes used in the offsite power connections are too vulnerable ~to single failures. Foreover, the design approach frequently treats the emergency generators as the preferred source of power rather than the offsite power system.
AP&L should review the design and revise as necessary.
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. AP&L and their contractors conmented on these items as follows:
1.
The analog signal goes to a bistable, the bistable output to the RPS; the B&W drawings will be changed to show the analog transmitter as well as the bistable.
2.
AP&L will modify the Technical Specifications to test the time delay relay. They will set the service water valve lineup to the lube oil coolers to suit autcznatic start requirements.
3.
AP&L has completed the design corrections as indicated.
'4.
AP&L is still checking.
5.
This treatrent of the torque switch is standard design; AP&L contends it is safe to leave it so. They further contend
-that these valves will restart in mid stroke; the high torque of interest is only at the end of the stroke.
6.
AP&L is still working on this.
.7.
AP&L is still working on this.
.8.
AP&L is still working en this.
9.
AP&L is still working on this.
(They are going to two power supplies.)
- 10. AP&L will review.
- 11. AP&L is still working on this.
- 12. AP&L is changing the duct location.
13 This item is open.
14 '. AP&L said there are only two safety related cables (DC power cables) under the Conputer Room floor; they are separated and in steel conduit. - - All safety related cables under the Control' Room floor are in PVC-coated flexible steel conduit.
-15 AP&L wondered if enclosing the trays would do. They expressed
, concern about meeting seismic criteria with the fire barrier.
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L16.. AP&L.will evaluat'e.
- 17. AP&L asked if this meant not even one; the answer was yes, not even one.
- 18.
AP&L agreed to.perfom a design audit for the. independence criteria of IEEE-308, especially regarding.the generator lockout relay.
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BICIDSURE 2 ATIENDANCE LIST ARKANSAS NUCLEAR O!E-UNIT 1 JANUARY 23, 1973
_ Arkansas Power and Light Company 9
W. Cavanaugh D. Rueter
~J. Grisham Babcock & Wilcox H. A. Baker G. F. Glei
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J. T. Walton R. R. Beach Bechte1 G. Katanics R. B. Linderman J. liaidinger B. Leonard J. Oszewski R, P. Schmitz' R.'J. Peyton L. E. Shipley USAEC-DL R. M. Bernem R. R.'Maccary.
S. N. liou 4
J. E. Richanison C. W. Moon R. A. Benedict J. A. Calvo T. A. Ippolito USAEC-RO J. H. Sniezek G. C. Gower D. E. Whitesell e
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