ML19317F861
| ML19317F861 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 11/19/1975 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19317F862 | List: |
| References | |
| NUDOCS 8002210599 | |
| Download: ML19317F861 (2) | |
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SACRAMEt!IO MUNICIPAL UTILITY DISTRICT O-6201 S Street. Box 15333. Sacrcmento. California 95813; (016) 452-3211 x/
November 19, 1975 4p[#6~~i"~7Ps
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n Mr. R. H. Engelken g.
Director of Regulatory Operations-C 3;
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HRC Operations Office, Region V-DEC-41975 a-C d
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1990 N. California Boulevard cgggfan
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Walnut Creek Plaza, Suite 202-df*uwn j
Walnut Crcok, California 94596 W
n Re: Operating License DPR-54 g
Docket No. 50-312
, Abnormal Occurrence 75-16 j.
Dear Mr. Engelken:
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AsdefinedbyProposedAmendmentNo.30toTechnicalSyccificatiod i
for Rancho Seco Nuclear Generating Station, Section 6.9.1, and Regulatory Guide 1.16, Revision 3, Section C.2.b.3, we are reporting the following Abnormal Occurrence as A0 75-J6.
It uns reported on October 29, J 975 that several of the Reactor p)
N' tape which had not been removed.
Subsequent investigation revealed that '
Building Spray System nozz1cs had, at some earlier date, been. covered with
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four of the nozzics had their spray openings covered by tape and tuelve other nozzles hajl tape on them uhich did not block the spray opening and -
did not ' affect their performance. Discussions with S!rdD maintenance personnel led to the conclusion that the tape uas placed over the nozzid.A to protect them during painting activity in the Reactor Building. At the:
completion of the work, which was done while the plant was still under; construction in mid 1974, the outside contractors doing the painting failed to-remove the. tape.
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To return the spray nozzics to operability, the tape will be removed from the four covered nozzics.
The Reactor Building Spray System is designed to remove heat and iodine from'the Reactor Building atmosphere following a loss of coolant accident. - These functions are also performed by the four Emergency Cooling Units.which circulate and cool the Reactor Building atmosphere. The Reactor Building pressure transient analysis, FSAR Section 14.4, analyzed building pressure buildup following a LOCA for several situations, including two cuergency coolers and one of the two spray systems operating, and four emergency coolers and no spray systems operating.
In all instances the 2
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lb) 13584 8002 210 $97
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f A ll F. I. C C T R I C ' S Y S I C M S LRVillC~ LAO RE T it A tt G 0 0,0 0 0 I t; T il E ItrART DI C A l t f 0 R il l a
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~ Mri R. H.:Engelien' -November 19,-1975 ~
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- peak, building-pressure is reached. approximately ftwenty seconds after j.
rupture and then decreases well~ before actuation of the spray systems (300' seconds.after rupture). The.four inoperative' nozzles represent-1
~two percent of the 199' nozzles in the Reactor Building Spray System.
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i Comparing this small amount of inoperative nozzles'with situations 7-F
-involving loss of'hhlf or.all of the spray system.(FSAR Figure 14.4-2, d'
Sheets 1 and 2).it-is clear that-in no case would the Reactor-Building
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design pressure of 59 psig'have'beeniexceeded.
Removal of iodine from"the atmosphere following a LOCA limits
. the offsite dose caused by leakage from the Reactor. Building. The design case ~for iodine removal is one of two spray syst'ms and.one of e
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two charcoal filters operable (two of four emergency-coolers hav a charcoal filters). There was.available during reactor operation more~
than the minimum spray system and both coolers witih filters, thus there was no. loss in design iodine remo' val.-
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9'A Periodic surveillancc testing on the-spray ~ systems and emergene.y coolers 'has been on schedule, insuring that both - spray systems an,d c11 four coolers were operable during the period of plant operation. The e
- spray system SFAS actuation Lwas tested 9/11/75 and 9/12/75 and the pumps
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and valves testing was.successfully performed 10/17/75.and'10/18/75.
F Tbc nozzle air flow acceptanc'e test was performed 5/30/73. SFAS testing 8
i of.the' emergency. coolers was performed =10/8/75 and '10/9/75 and the cooler fans were testcd 10/17/75.
All systens. passed the' reqtiirenients of the t'es ts.
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.The health and safety of the public'wa's'not endangered by the taped nozzles, due to'the' availability of all systems for Reactor Building!
atmosphere cooling. and iodine' removal and the minimal effect of blockind1
- such a small number ~of nozzles. There'was no plant transient associated with~this event.-
r Respectfully,
..% K.x J. J. Mattimoc
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Assistant-Concral Manager and Chief Engineer ~
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Enclosurer s Director, MIPC(3)'.
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g Director,.-IE(30)
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