ML16238A339

Forwards LER 80-042/03L-0

ML16238A339
Person / Time
Site:	Fort Saint Vrain
Issue date:	08/22/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML16238A340	List: ML16238A339 ML19344D996
References
P-80279, NUDOCS 8008260488
Download: ML16238A339 (14)

Text

DUKE POWER COMPANY POWER BUILDING 422 SOUTH CHURCH STREET, CHARLOTTE, N. C. 28242 WILLIAM 0. PARKER,JR.

VICE PRESIDENT TELEPHONE: AREA 704 STEAM PRODUCTION 373-4083 August 18, 1980 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. R. W. Reid, Chief Operating Reactors Branch No. 4

Subject:

Oconee Nuclear Station Docket.Nos. 50-269, -270, -287

Dear Mr. Denton:

In a letter dated December 20, 1979, the NRC provided a safety evaluation approving the preliminary design of the proposed safety grade anticipatory reactor trip. Included with this approval was a request for additional information. The attached information is provided in response to the Staff request.

For the information of the Staff, the initial unit which will have this system installed is expected to be Oconee 3, which is anticipated to be shut down for re ueling in November, 1980.

Ve truly yours, William 0. Parker, Jr.

RLG:vr Attachment 8008260488

• ..

Oconee Nuclear Station Anticipatory Reactor Trip Information Needed for Final Design Approval SER 3/4. The final design submittal should include the final logic diagrams, electrical schematic diagrams, piping and instrumentation diagrams and location layout drawings.

Response

The final design drawings will not be completed until immediately before unit shutdown for implementation of the anticipatory reactor trip. .Based on the above schedule, the detailed drawings.

requested will be available for inspection at the plant site.

It should be noted that in a May 21, 1979 letter from Parker to Denton logic/block type diagrams (and a system description) were provided which should be sufficient for review and understanding of this system.

SER 4, For sensors located in non-seismic areas which have not previously contained RPS inputs, perform and submit an analysis which shows that the installation (including circuit routing) is designed such that the effects of credible faults (ie,, grounding, shorting, application of high voltage, or electromagnetic interference) or failures in these areas could not be propagated back to the RPS and degrade the RPS performance or operability.

Response

The sensors for the anticipatory reactor trip are separated both electrically and physically for redundant and independent operation.

These sensors are provided with individual termination enclosures to protect against grounding, shorting, and environmental conditions.

Interlocked armour cables transmitting the signal to the control room are placed:in conduit or safety grade cable trays the entire route to guard against any application of high voltage or other credible faults, The design is such that a single failure will not prevent the sensors from performing their function, The sensor inputs are provided with a 500 volt isolation buffer, Since the sensors are anticipatory in relation to other trip parameters, the reactor protection system will not be degraded by the failure or fault of the anticipatory trip.

SER 4. Submit."Seismic and Environmental Qualification Summary Reports" for the equipment which has not been previously submitted. In addition, we require that you demonstrate that the environmental test conditions bound the actual worst case accident conditions expected at the installed locations.

Response

The seismic and environmental qualification test reports for the pressure switches used in the anticipatory reactor trip system are provided in Attachment 1 to this letter. These switches are qualified for the worst case environmental conditions expected at their installed location, SER 4. Assure that the ARTs testability includes provisions to perform channel functional tests at power. Testing of this circuitry is to be included in the RPS monthly surveillance tests.

Response

Testability of the ARTs will be provided at power by isolating each sensor and simulating a main turbine or feedwater pump trip. This is done by releasing pressure from the sensors and verifying that a trip signal is indicated at the RPS and that proper indications have been actuated in the control room.

Each pressure switch and channel will'be tested and evaluated in the same manner. ARTs circuit testing will be done monthly along with the existing RPS, SER 5. Include in the final design submittal the RPS check-out procedure which will demonstrate both the operability of the new trip circuitry and the continued operability of the previous RPS,

Response

The existing RPS is field calibrated annually and circuit tested monthly, The field calibration consists of complete channel and equipment verification of setpoints and trip signals, Monthly circuit testing is done at the cabinet by actuating test modules.

The ARTs will be tested on the same schedule as the present.RPS.

Monthly testing of the ART will be the same procedure as existing RPS. The annual and initial calibration will consist of the above described activity. The new trip test circuitry will be added to the existing test trip string.

Detailed check out procedures for the system are retained at Oconee and will be available for site inspection.

Custom Control Sensorsinc.

21111 Plummer Street, Chatsworth, California 91311 -(213) 341-4610 TWX 910-494-4770 STATEMENT OF SIMILARITY BETWEEN MODELS GROUP A. AND MODELS GROUP B GROUP A: 646GZE1, 2, 3,5,7 and 11 646GZEMI,2,3,5o7 and 11 GROUP B: 604VB1-351S, 604GBR2-352S 604GR6-35SS, 604GCRO-357S The subject switches are identical in basic desicn. Both of the groups of models use disc springs flexible diaphragms to sense a rings and and transmitnr cl to electrical switching elements. pressure -.ariations The significant difference between the two s n the configuration of the electrical grou-s. of models switching elements.

Because of a specific customer requirements, use a DPDT electrical switching element Group B modals configur- o Md in Group A utilize an explosion proof housed SPD and DPDT 1 electrical switching element configuration.

proof electrical configurations offer equal These explosion resistance to seismic vibrations. or superior The construction differences between these modis should not affect their function or performance.

All models are comn pa--able with respect to. finish, function, m.anship and overall quality. engih eering, work Custom Control Sensors submits that the seismic on Group B models are also applicable to Grouo A.tests models.

perforrnei men the basis of the indicated similarity it is and enciozed test data proposed that seismic qualification to Group A models.

approval be granted Test report QTR604*-01 is submitted for Philip Dtlon Chief Engineer Manufacturers of pressure, flow and temperature switches for airborne, aerospace and industrial uses

CUSTOM COMPO E VASWITCHES, INC.

21111 PLUMMER ST. CHATSWORTH, CALI F. 91311 CUSTOM COMPONENT SWITCHES, INC.

ENVIRONMENTAL TEST REPORT ON MODELS 646GZEM11, 646GZEM2-7011, 646GZE5 i

Prepared b Quality Assurane Engineer Approved bv Quality Assurance Manager

CUSTOM (0PONEN SWITICES, INC.

21111 PLUMMER ST. CHATSWORTH, CALIF 91311 SCOPE This report outlines the results of environmental tests conducted at Custom Component Switches, Inc.

RE~~CE S In-house requests by the engineering department.

OBJECTIVES e objective of this test was to demonstrate that Custom Component S:itches 646GZZ,11 646CEM2701 and 646ZE5 would fullo compo with the general reciirements of CCS.a Durinc these tests all 3 units ments. met or exceeded the specified require DESCRIPTION cf TEST SW ITCHES Three pressure switches were tested.

and 646GZE5. Model 646GZEM11, 646GZEM2-7011 The above switches were assembled These witches did not receive, from standard production parts.

in the manufacture of all Custom any special treatment beyond that Component used models. pressure switches of these TEST PROCEDURE - 646GZEM2-7011 and 646GZEMl1

1. The pressure setting of each unit was adjusted to the top range.. of its 2.. The settings were checked and recorded at room

-30 0 F and back at room temperature. temperature, +30 0 F, he settings were then adjusted to the bottom of the range steps I and 2 were repeated. and NOTE: At each temperature the units were allowed to stablize for

• one hour.

CUSTOM COMPONENPSWITCES, INC.

Environmental T/R 21111 PLUMMER ST. CHATSWORTH, CALIF. 91311 Page 2 TEST RESULTS MODEL: 646GZEM2-7011.

RANGE: 9 to 75 PSI D/B: 9 PSI Maximum TOP RANGE . BOTTOM RANGE TEMP F D/B INCREASE DEEA E INCREASE DECREASE D/B Room 3.5 70.2 66.7 9.0 2.8 6.2 3007 3.5 71.0 67.5 9.5 3.2 6. 3 00F 3.0 71.5 62.5 9.7

-30 0 F 3.0 72.5 3.4 6. 3 69.5 10.0 3.Q 6.1 Room 3.5 70..0 66.5 9.3 3.0 6.3 MODEL: 646GZEM11 RANGE: 12 to 150 PSI D/B: 12 PSI Maximum TOP RANGE BOTTOM RANGE TEMPoF D/E INCREASE D CREAS INCREASE DECREASE D/B Room 8.0 156.5 148.5 12.0 8.2 3.8 30 0 r 8.0 157.5 149.5 13.2 0OF 9.3 3.9 7.5 158.5 151.0 13.6 9.6 4.0

-30oF 7.0 159.0 152.0 15.2 10.7 4.5 Room. 7.2 . 154.2 146.0 13.1 9.0 4.1 TEST PROCEDURE - Model 6460ZE5 The unit was initially tested at room temperature and factory points were determined. The unit was then installed inside the temperature chamber and was .actuated and deactuated twice at e the following temperatures;. -300?, at room, +1600F and back at room temoerature. The set points at each temperature were recorded.

The temperature was then increased to 2000? and the unit was operated 5000 times at a rate of 60 times Der minute. Set points were checked and recorded twice at every 100C cycle interval and acain after 5000 cycles at room temoerature.

NOTE: At each temperature the unit was allowed to stabilize for one hour.

CUSTOM COaPONE PSWITCHES, INc.

Environmental T/R 21111 PLUMMER ST. CHATSWORTH, CALIF. 91311 Pace 3 TEST RESULTS - Model 646GZE5 TEMPERA TURE INITIAL HYSTERISIS INCREASE PSI DECREASE PSI INCREASE PSI DECREASE PSI Room 569 543 566 543

-30 0 F 574 543 570 546 room 570 542 566 543

+160OF 569 539 561 539 Room 576 544 571 545

+200 0 F Cycle 5K times K=1000 1K 566 537 564 536 2K 567 535 561 533 3K 561 534 560 534 4K 560 534 558 532 5K 562 534 559 533 Room 572 539 567 538

Ib' CUSTOM COLPOIENT SWITCHES, INJC.

21111 PLUMMER STREET. CIATSWORTil, CALIFORMIA 91311 EVALUATION TEST REPORT Subject Custom Component Switch Model Numbers 646GE2 and 646GEM2 Objective The objective of the tests was to evaluate CCS switch Numbers 646GE2 and 646GEM2 under varying vibration Model to determine the electrical chat'ter characteristics. levels Description of Test Switches Two units of Model 646GE2 containing a CCS 79-9 and two units of Model 646GEM2 containing two switch element elements. CCS 79-1 switch Test Procedure Each test unit was mounted on the vibration shaker vertical axis .(with its electrical housing on top in the port on the bottom). With the pressure set points and the pressure middle of the range, it was subjected to vibration adjusted to the to 2000 Hz at varying acceleration g levels. Each scans from 5 was tested at both actuated and deactuated conditions. pressure switch acceleration g level was observed on the oscilloscope The continuously monitoring the normally open and closed which was The test was repeated with the unit-adjusted at the contacts.

pressure set points. minimum Test Results The results of the electrical contact chatter occurrence graphically presented in Figures 1, 2, 3, and 4. are Model 646GE2 switches with CCS 79-9 elements showed contact chatter at lower g and frequency levels electrical 646GEM2 units with CCS 79-1 switching elements. than the pressure range (1/4 turn of.helical spring compression), low At the contacts began to chatter at 5 g's and 20 Hz. At the electrical contact disturbance prevailed at .5 500 Hz, the mechanical resonance frequencies were found at g level. The and 2000 Hz. 550 Hz, 900 Hz

A. -2 On the other hand, 646GEM2 units containing CCS 79-9 elements did not show any evidence of electrical contact disturbance until at 40 g's input. Electrical contact chatter at lower g levels became possible only after the test units were scanned from 5 to 2000 Hz at 40 g's. Since there were several mechanical resonances occurring at 560, 1340, 1740, 1895 and 2000 Hz, a continuous 40 g vibration sweep could have had affected the units structurally and caused to chatter at the lower g levels.

Aki Okada Engrg Lab Supervisor 1-22-76 jam

• 17.

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