ML19330B740
| ML19330B740 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 07/31/1980 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-80-17, NUDOCS 8008050437 | |
| Download: ML19330B740 (7) | |
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- .!r James G eppler Office of Inspection and Enforcement Regien !!I U S :Iuclear Regulatcry Cc=ission I99 Roosevelt Road Olen EL/n,. L c0137 C..., e,C.~rc.e.w..r e..e, a.
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00:CROL RCES TO FULLY ::! SERT CURI!G A SCPXI AT A 3*a'R IE Bulletin :Io 80 '.7, " Failure of 76 of 135 Control Reds to Ful'.y Insert During a Scrs= at a 3'a*R", dated July 3,1960, required scrss testing in accordance with Ite: 2 of the 3ulletin to be co=pleted within twenty (20) days of July 8,1980, (3ulletin clarification lated July 7,1980).
- n addition, verification of func-tional venting and absence of water in the Scra: Dump Vol=e (SDV) was required by Ite: 3 of 'he 3u11etin.
Consumers Pcver Ceepany ec=pleted the required =anual and automatic scras tests on July 24, 1980, and July 25, 1980, respectively. The tests were conducted with =cre than 50 percent of the centrol rods fuuy withdrawn. Specific respenses to the Hulletin require =ents are provided fer Ite=s 2 and 3 by the attach =ent.
Sene significant features of the Big Rock Point design should be understood when evaluating the results. The active SDV is totally within the Scrs= Dump Tank (S;T) having a 175 gallon capacity which is in excess of two full scras discharge quanti-ties. The SDV piping is =aintained water filled at all times due to a loop seal i==ediately ahead of 300 inlet. The SDT instrumentation provides a centinuous
=ccitor en water level. The syste= has a built-in safety feature of a high level slar= annunciator near the bottc= cf the tank (approni=ately 2" frc= the bottc=)
to ensure no appreciable water exists in the tank and as a backup to the " alar ="
utili:es a high dump tank "scra=" which places a trip into the Eeactor Protection System when the tank is approxi=ately one-half full (5/16" below centerline) thus unequivocably ensuring adequate margin for serss water is available. "he high level scrs= feature precludes resetting the safety syste= in the "run" or "r *uel" =cdes with an inappropriate a= cunt of water in the tank.
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. 80080501 3 7
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- b James ~G Keppler 2
Big Rock' Point Plant July 31, 1980 The results of-the ' tests verify that the control rods can be scrammed composite-ly frem a full outL condition, the SDT sizing is more than adequate, and the SDT vents and drains function properly.
l This response was delayed for one day to meet with the NRC personnel.at Region l
- III to discuss these results and the as-built system. Mr Duane Boyd, of your f
staff, was informed of the delayed and accepted it based on our attendance at l
the July 30, 1980, =eeting.
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- avid ? Hof'ftan (Signed)
David P Hoffman Nuclear Licensing Administrator CC Directer, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforce =ent L
NRC Residant Inspector - Big Rock Point Plant Attachment (4 pages)
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CCNSDtEES PC'4ER CC:G/J:Y Big Rock Point Plant
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II Bulletin 80-i*7 Docket 50-155 License ~DPR-6
- At the ' request of the Comission and purusuant to the Atemic Energy Act of 1954
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and the Energy Reorgani::ation Act of 197h, as scended, and the Cc==ission's Rules and Regulations. thereunder, Consu=ers Power Cc=pany sut=its cur response to Ite=s No 2 & 3 of II Bulietin 80-17, dated July 3, 1980, entitled, " Failure of 76 of 165 Centrol Rods to Tully Insert During a Scra= at a 3'4R".
Consumers Power Cc=pany's response is dated July 31, 1980.
CCNSU:ERS PCWI.R C0!GA. l T
By R C Youngdahl (Signed) l_
R C Youngdahl, Executite Vice President l
~ Sworn and subscribed to tefere =e this 31st day of July, 1980.
Linda $* Cestens (Signed) l Linda K Carstens, Notary Public (gggL)
Jackson County, Michigan-My cc mission expires June 10, 1981 l
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SIG ROCK POI:iT PLA:IT II 3UL1rI!i:10 80-17, ITEMS 2 't 3
SCRAM TEST RESULTS Ite= 2
- 41 thin the next 20 days, perfor= one =anual and one autc=atic sera = in that order at nor=al operating temperature and pressure and with =cre than 50 percent of the rods fully withdrawn, and obtain the folleving infor:ation on each scrs=:
Respense to Item 2 The specified nanual and autc=atic scrs=s were perfor ed on July 2L,1980, and July 25, 1980, respectively. Results of these tests indicate that the scrs=
syste= including the discharge volu=e function as designed.
Ite= 2 s All red insert times and as =any individual rod scrs= times as practicable.
Respense to Ite= 2 a All reds were ti=ed on the insert scrs= stroke via three =ethods: stop vatch, video tape and 35== ca= era..The two stop watches caught "all rods in" in the 1.3 and 2.1 seconds, well within the < 2.5 second Technical Specifications criteria.
Initial rerun of video tapes show all rods vere fully inserted well within the Technical Specifications li=it of4 2 5 seconds. The ca= era fil has been develop-l ed and the first scra= test is out of focus and is unusable. The second scrs=
l (auto initiative) shows all rods full in < 2.00 seconds; again vithin the Specifica-tiens. Seven individual reds were also ti=ed using strip chart records and all j
vere within Specifications, f
Ite= 2 b l
Voltage at the scra= solenoid valve buses to verify that these solenoids are l
de-engerized upon receipt of scra= signal.
Respense to Ite= 2 b Voltage at the scra= solenoid valve buses was =onitored in each of the tvo cases and the voltage reduced / fell to :ero as required upon scrs= initiation. This
casurement was =ade via a voltmeter (digital) at the Reactor Protection Syste
(RPS) terminal strips as well as verified by "off-set pens" on the RPS Events Recorder.
Iteu 2 e Verify that sers=. valve air is relieved thrcugh the backup valves and that the backup valves are fully open and renain open during the presence of a scrs=
signal.
Response to Ite= 2 e JAir pressure was verified to be relieved frc= the master sers= solenoid valves and the valves were also verified to remain open for the duration of the scram.
This was done by an Auxiliary Operator stationed at the valves vitnessing ribben novement in the discharge air stres as well as holding his hands on the solenoids to ensure deactivation (this was easily deteated).
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2 Ite: 2d Xeasure fill ti=e of the instru=ent volume frc= scra= initiation to closure of
.the sers= instru=ent vol=e high level alar = switch, to closure of the rod with-draw block switch on the instr =ent vol=e and to the closure of the sers= instru-
=ent volu=e reactor scras switch.
Fesponse to Ite= 2 d The ti=e required for the scra= du=p tank volu=e to fill to the a) high level alar: point, and b) the SDT high level scra= point was =easured. For the manual scrs=, the times were 9.63 seconds for the high level alars and 60.k8 seconds for the high SDT level sers= cocparing very favorably with the auto =atically initiated scrs= ti=es of 10.19 seconds for the high level alarm and 53.51 seconds for the high level scrs=.
Also ti=ed vere the sequence of all four of the Reactor Protec-tion Syste= scrs= sensor switches on the SDT.
In each case, the time fro = the first switch to open to the last svitch to open was five (5) seconds. This is consistent with the ;1 ant's routine Surveillance Test Procedure acceptance criteria, 4105 of total ti=e.
Ite: 2e Measure vent and drain valves opening and closing ti=es utilising the valve ste:
=cunted switches. This =easurement =ay be made independent of the scrams.
Restense to Ite: 2e The SDT vent and drain valve opening and closing ti=es were measured while being actuated by the re=ote manual hand switch in the control room. The closing time was k5 seconds and the opening time was approximately one (1) second. This test was made, as the Bulletin allows for, prior to the actual scrs= tests.
Ite: 2f Measure the delay ti=e from scra= initiation to closure of the SDV vent and drain valves utili:ing the sten =ounted position switches.
Response to 2 f The delay time fro = scra= initiation to the closure of the SDT vent and drain valves was =easured during the scra= tests. This was done by an operator in the control roo= ti=ing with a stop vatch the valve position indication lights which are actuated frc= the valve ste=-=ounted switches. Ti=e of closure (both valves are served by one set of lights) during the =anual scrs= vas 15.7 seconds and following the automatic scrs= vas 17.2 seconds.
Note: This closing ti=e differs from that =easured in (e) above as the solenoid air discharge path is not the same for the two features.
Ite= 2 g Sample water fro = the instrument volu=e discharge after each scrs= for particulates.
. Response to 2 g Water sa=ples were taken fro = the scrs= discharge vol=e after both scrs=s; follow-ing the =anual (first) scrs=, the water as expected was very discolored frc= =enths
3 (some.seven =cnths). of continuous reactor operation with no sera = initiated to cleanse the piping and tank. The sa=ple following the autc=atic scra: vas pre-dictably more clear. Some four (L) gallons of water vere collected during each drain cycle. The suspended solids were 205tp: fcr the manual scra= sa=ple end 13.6 pp: for tne aute=atic scram sa=ple.
Ite: 2h
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Measure the ti=e to drain the SDV down to a repeatable reference level.
Res;cnse to Ite: 2h The ti=e to drain the SDT volume devn to a repeatable level was verified.
'4 hen the RPS.is reset, the scra: annuncistor i==ediately clears for the "SDT hign level scrs=".
The ti-a '--- drain initiation to the clearing of the "high level alar =" vas three (3) =inutes, 57 seconds for the =anual scra: and three ( 3) =inutes,
52 seconds for the autc=atic scrs= with a tank e=ptying ti=e of four (k) =inutes, 25 seconds and four (k) =inutes, 23 seconds, respectively.
!te: 2i Sionitor the SD7 and associated piping for residual vater.
Response to :te= 2 1-Th'e-Scrm: Du=p Tank (S Ti volu=e was =cnitored for residual vater prior to the scrs= tests and after each of the two tests. Radiographic =ethods were used as the tank thickness and ge0=etry prohibited the use of the ultrasonic tech =iques.
The tank vas verified tc' be e=pty in each case.
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%cte: The 31g Rock Point design is such that the SDT volu=e is sized adequately i
-to accept two full sers=s and the SDT high level scra: switch locations ensure this feature to be available when needed. Also, the du=p tank headers are designed to be full of water via a loop seal at the entrance to the-SUr._
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_ I, tem 2 3 Verify that _ the ten (10) seconds delay on scra= reset is functioning properly to
' prevent resets of =e=entary scra signals.
?esponse to Ite: 2j
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' The ten seconds ti=e delay on scra= reset is not designed into the Big Rock Point syste= and is not applicable to this test. This was verified with NRC Region !!!
- persennel as vell as the Resident Inspector.
'It e 2k 1
. Cc= pare the results of the_ two sets of_ data taken above with each other and with -
.any previously obtained data.
. Response to Ite: 2k i
The results of the data vere ec= pared with each other as well as to data.previously obtained. -Agree =ent seems to be good in each case.and no discrepancies were noted.
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Item 3 At the conclusion of the scra= tests and all other scra=s, verify that all vent lines on the SOV are functional. Verify that there is no significant a=ount of water in the SLV and associated piping.
Restonse'to Ites 3 J At the conclusica of each' scram test, when. venting and draining of the SDT was initiated,' the vent line vas verified to be open and functional. This was evidenc-ed.by the. discharge of water from the vent for a shcrt period (few seconds) and the position of the vent valve stem indicating an open valve. The SDT vas verified to be. empty via the radiographic =ethod discussed in Item 2 i above.
The. daily check for vater in the SET was perfor ed after each scram test and con-tinues as prescribed in Bulletin Ites No 5 and Supplement No 1.
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