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D. L. Caphton October 9,1973
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E. C. Greersaan Telephone Report a The Istmanent Fix on the Diesei Generators at Oyster Creek The permanent fix et Oyster Creek (OC) involved the installation of two relays and a jtamper wire. The jusper wira sus around a relay contact - the DLU contact. In essence, this perndts the fast-start relay and the two new ad-ditional relays to be energised even if there is en engine fault present, The jumper amables the fast start reig, the FSE reley, to pick up the two new relays at the seem time thet the fast-start relay is energised -e so all three of these relays are essentially energised at ths sene time. Now each of the two new relays has a cantact that goes around the manual reset button ~ one contact on the relay that is desnergised is open and the other contact is closed. When you energise these two relays, the contact that is open closes, and the contact that was already closed opens after a 5-second time delay, so that sesentially, what you are doing, is pushing that reset button through the circuitry, with no more than a 5-second delay. The plant ran a valid test, a fast-start sequence, against an engine fault and they were able to get a fast-start, and this does represent the permanent fix --
this was installed the let of October and it was reviewed by PORC.
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10/9/73 9604150061 960213 PDR FOIA DEKOK95-258 PDR
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October 8, 1973
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.' ' ' aq lir. - Robert' J. Schemel, Chlef -
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Directorate of Licensing
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Office-of Repulation.-
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U.S. 4tomic Energy Commission r'!;
Washine, ton, DC-20545 O
Dear lir. Schemol:
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SUBJECT:
OYSTER CREEK HUCLE/Ji GENERN1TNG STATION
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DOCRET 140. 50-219' INFORMATION RECARDING THE DRYWELL VACUtn1 BREAKER V/JNES Upon roccipt. of your January 22, 1973 1ctter, the position'of the subject valves.uan cheched and verified to be closed.
Consequently, no rcrrodial action vac necessary.
.Subcnquent to that tinc, uc centacted Cencral ticctrje. an' hawa
- cmployed their servjces to prepare the r.nalytical data requested in your
'ictrer.
The.information is not yet avni.labic.
General L.iectric cannot
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spec 1fy.a: comp 3 ction date at this tine, but we vil) inform you by November - 15, 1973 of the. status of this. request.
Upon receipt of this information,- the ansuers to your questions 8 through 13 vill be nubmitted.
The recponses to questicas 1 through 7 are cttached.
Illustrative diagrams, which are to be considered proprietary, arc being submitted under separate cover.
. ' During the spring 1973 refueling outage, a leak rate test was conducted to determine the bypass area from the drywell to the torus.
The results.indicat.cd a leakage area which was significantly Icss (7-2%)
i thnn the bypace area which G.E. has determined to be liv;iting for several of its other plants.
The details of this test and other related tests were reported in
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semi-annual report f8.
However, the allowabic bypass area was in error and a correct. ion to the report will be made.
Very truly yours, f
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D. A. Ross Manager i
LDAP/NGT/ab-Attachment
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Question No. 1:
Manufacturer, model number, ratings, and modifications, if any, of the vacuum breakers.
Answer:
The torus to drywell vacuum breakers were built by Atwood G Morrill Company of Salcu, Massachusetts.
The following infor-mation is pertinent to the valves:
Atwood 6 Morrill Drawing No. 20464-H-ALT.1 Size:
18 inches Rating:
150# ASA Standard Question No. 2:
Installed assembly drawing, including testing equipment.
Answer:
This drawing is considered proprietorf information by the Atwood G Morrill Company and may not be released to the public without their written consent.
The only difference between the drawing and the installed valves is that the cast iron weights, Part #5, have been removed, as they were not required for proper valve operation.
Question No. 3:
Materials used in the vacuum breakers, including seals, seats, bearings, lubricant, body and operating parts.
i Answer:
The list of. materials is shown on the proprietory drawing referred to in No. 2 above.
Question No. 4:
Capability of parts sad their design life in the most severe suppression chamber or erational transient and accident environ-ments.
Discuss possibla deleterious effects of chemicals present during the surface preparation and application of the suppression chamber coating and of nitrogen on vacuum breaker system materials.
Advise what tests have been performed on the vacuum breakers and their position indication system in a simulated accident environ-ment.
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Answer:
All parts of the valves are designed for sustained operation at tempetatures in excess of 300* F.
The maximum temperature expected during the design basis accident is 275* F. at 33 psig which is well below the capabilities of the valve.
During con-struction of the suppression chamber, no chemicals were used to prepare the surface prior to paint ~ ng.
The inside surfaces were merely sandblasted.
Furthermore, because the vacuum breakers and their associated piping are located outside the suppression chamber, it is unlikely that the valves' internals were exposed to an unfarsrabic environment at that time.
Discussions with the valve manufacturcr have indicated that the inert nitrogen atmosphere to which the valves' internals are exposed during operation should have no adverse effects.
No tests have been performed with these valves in a simulated accident environment.
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Question No. 5:
For the tests performed on each vacuum breaker system, provide a brief description of acceptance criteria and test results including:
a)
Preoperation and periodic surveillance tests, b) Other tests and reasons for the tests.
Answer:
a) The following preoperational tests were conducted:
1.
Measure the force to open the vacuum breakers and the force necessary to hold them open.
a) This was performed by General Electric and was 3
designed to ins ~ure the vacuum breakers would open at 0.5 psi across the valve.
The test was done by means of a spring scale attached to the weight IcVer at a distance 30 inches from the shaft center-line, in order to verify that the valve would open with a pulling force less than 20 pounds. This is equivalent to a differential pressure of about
.25 psi.
The last step of this test was to insure the valve disc returned freely when the spring scale was *c) cased, b) All vacuum breakers successfully passed the pre-operational test outlined above.
2.
Each valve and associated piping was checked to assure that they were clear of foreign matter.
3.
Checks were made to insure there was no restriction to valve lever movement.
4.
A drywell leak rate test was conducted tv insure that the valves seated, i
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Each valve was actually tested to insure it opened with 0.5 psi across it.
This test was done by installing and inflatable seal on the torus side of the valve piping and pressurizing the piping between the seal and the valve.
b)
The following surveillance tests are performed:
1.
Each torus to drywell vacuum breaker is exercised during i
cach re fueling outage to insure proper operability.
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2.
Each refueling outage, the vacuum breakers are tested by means of the spring scale at the end of the weight IcVer. The force to open and hold open is mecsured and recorded.
In the event the force to hold the valve open does not fall within the allowable range, corrective action is taken and the valve is retested.
Question No. 6:
A description of corrective action taken to remedy any failure of the vacuum breakers, including a discussion of the cause of the failure.
Answer:
The vacuum breaker valves have established a history of maintenance requirements. The valve bushings are manufactured of teflon which has a characteristic of " growing" and occasionally causes the vacuum breakers to fail the surveillance test.
hhen dis-covered, the valve bushings have been repaired and the valves tc:tcd to insure that they pass the tests before startup. The
" growing" characteristic has been experienced by several plants with teflon bushings. The mechanism by which this occurs is not fully understood at this time.
It is suspected, however, that both radiation and moisture will cause teflon to grow.
Because these valves are operated very infrequently, the bushings do not wear enough to compensate for the growth.
In some cases, this causes the valves to operate sluggishly and ' fail a surveillence test.
1 As reported to the AEC by both telephone and letter dated J anuary 17, 1973, the bushing problem has been recognized and discussed by the Plant Operations Review Committee (PORC).
In this regard, the PORC has required that an investigation bc conducted as to the suitability and leng range applicability of the present packing material.
The bushing difficulty has been discussed with Atwood 6 Morrill Company and a long term solution is being investigated.
The probabic solution will be to replace the bushings with a material that is more suitable for the application.
The material and bushing design is under study by the General Electric Company and Atwood 6 Morrill Company.
As a continuing action, Jersey Central Power 6 Light Company's personnel will test the valves each re-fueling outage per the plant procedures, as well as insuring the valves are closed prior to startup af ter a refueling outage.
There have been no other maintenance problems experienced with the valves.
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Question No. 7:
A description of the station procedures or checks used to assure that the vacuum breakers:
a) function properly prior to startup b) are closed after completion of pre-startup functional checks c) are maintained properly.
Answer:
a)
During each refueling outage, the vacuum breakers are tested to insure proper fungtion in accordance with plant procedures as explained in reply 5.b.1, 2 and 3.
b)
Prior to startup after a refueling outage, the vacuum breakers are verified to be in the closed position by actually checking the valve, c)
Each vacuum breaker valve is inspected and tested each re-fueling outage and in the event an abnormality is discoveted, it is corrected prior to startup.
Any abnormality is re-corded and investigated or, when required, the manufacturer is contacted for further information and assistance.
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For faformation.
g 10 (Nase s'stod vaat) intIIALS ALMARES RO TMRPFmTOht REPORT NO. 50-219/73-13
!!. D. Thornburg, Licensee:
Jersey Central Power & Light Company Chief, FS&EB To :Na-..a
.,edt INWALS REMAANS cc:
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The subject insp.m: ion report is forwarded for 2 Central Files
.eg. Standards (3 )oAre your information. Distribution will be made Directorate of Licensing (13) by this office to the PDR, LPDR, NSIC, DTIE t o e4.m..a va o imnus nu4ans R0 Regional Direc : ors and State representatives after review by R0 Files the licensee for proprietary information.
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Facility Operations nennch P&ONC DC DATE 10/4/73 uu orm, we son,oomom unass om o.n o........
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