05000029/LER-1986-005, Forwards LER 86-005-00 Re Primary Coolant Dose Equivalent I-131 Greater than 1 Mci Per G

Forwards LER 86-005-00 Re Primary Coolant Dose Equivalent I-131 Greater than 1 Mci Per G

ML20203K187
Person / Time
Site:	Yankee Rowe
Issue date:	07/02/1986
From:	St Laurent N YANKEE ATOMIC ELECTRIC CO.
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8608060291
Download: ML20203K187 (1)

LER-2086-005, Forwards LER 86-005-00 Re Primary Coolant Dose Equivalent I-131 Greater than 1 Mci Per G

Event date:
Report date:
0292086005R00 - NRC Website

text

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YANKEE ATOMIC ELECTRIC COMPANY r.i.on on.c<,s><2<.82e, 3 tar Route, Rowe, Massachusetts 01367

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July 2, 1986 -

U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Dr. Thomas E. Murley, Regional Administrator

Subject:

Licensee Event Report 50-29/86-05 Dose Equivalent I-131 > 1.0 Microcuries per Gram

Dear Sir:

In accordance with 10 CFR 50.73(a)(2)(ii), the attached Licensee Event Report is hereby submitted.

Very truly yours, c4t Y $l44%

Normand N. St. Laurent Plant Superintendent JAK/nm Enclosure cc: [3] NSARC Chairman (YAEC)

[1] Institute of Nuclear Power Operations (INPO) 8608060291 860702

{DR ADOCK 05000029 PDR 3 -6 31

U S. NUCLEJ.3 S EIULATORY COMMtGS40N NRC form 300

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""'** I LICENSEE EVENT REPORT (LER) l PA.E m 1 DOC-T NeMSE R ,,,

.AC,LT.NAMEo, Yankee Nuclear Power Station, Rowe, Massachusetts o l51010 l 0 l0 l2 19 1 lorl 0 l 4 TITLE tel Dose Equivalent I-131 > 1.0 Microcuries per Gram  ;

EWSNT DATE (S) LER NUMSER ISI REPORT DATE (7) OTHER F ACILITiES INVOLVED IS)

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{ 50.73(eH2Hal 50 73(ell 2Hal 20 408'eH1Hel 60.73teH2Heul LICENSEE CONTACT FOR THl3 LER (12)

R. Mellor ARE A COoE Chemistry Department Manager 4 1 3 4 I2 I 4I 5 I26 I I1 I I I COMPLETE ONE LINE FOR EACM COMPONENT FAILURE DESCRISED IN TMis REPORT (13)

• C. REPORTA LE CAUSE SYSTEM COMPONENT C RE RTA E CAUSE SYSTEM COMPONENT Mh y pq U

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! l l 1  ! l 1 1 I I I I i 1 SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR SUGuis$f 0N YES IIf ven, earnparte LM*ECTfD SUG6tISSION OA TEI NO l l l ASST:. ACT w,,,,r ae uaoc ac . . . . w, ur aa?. .o,< rve.-aw. s ol, On June 2, 1986, at 0110 hours0.00127 days <br />0.0306 hours <br />1.818783e-4 weeks <br />4.1855e-5 months <br />, following a plant scram with the plant at 0% power in Mode 3, the primary coolant dose equivalent I-131 (D.E.

I-131) was determined to be 1.35 microcuries/ gram exceeding the Technical Specification LCO (3.4.7) of 1.0 microcuries/ gram. The primary coolant D.E. I-131, reduced through increased purification flow (from 26 to 48 GPM), was determined to be 7.49 E-1 microcuries/ gram on June 2, 1986, at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />.

The root cause of the event is considered to be cladding defects in second cycle Core XVIII fuel assemblies which will be removed during the Core XVIII-XIX refueling scheduled for May 1987. Similar events were reported in LERs 77-55, 78-03, 78-19 and 78-23.

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'" urnovEo oMe No mo-oio4 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION EXPtRES.8/31185 FACILtTY NAME (1) DOCKET NUMEER (2) LER NUMSER 166 PAGE131 Yankee Nuclear Power Station vs si=p*6  ;*y,;;

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On June 2, 1986, at 0110 hours0.00127 days <br />0.0306 hours <br />1.818783e-4 weeks <br />4.1855e-5 months <br />, with the plant at 0% power in Mode 3, the primary coolant dose equivalent I-131 v:as determined to be 1.35 microcuries/ gram exceeding the Technical Specification LCO (3.4.7) of 1.0 microcuries/ gram. This event, which continued until 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on June 2, 1986 (a duration of six hours and fifty minutes), was mitigated through the use of increased letdown (clean-up) flow. During the course of this event, the sampling requirements of T.S. Table 4.4-2 were maintained. .

The plant was at 0% power as a result of a reactor scram on June 1, 1986, at 2034 hours0.0235 days <br />0.565 hours <br />0.00336 weeks <br />7.73937e-4 months <br /> (LER 86-04). This LER is being submitted to provide the reporting details required under Technical Specification 3.4.7 Action a. The results of specific activity analyses and the reactor power history and letdown flow history starting 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the '

event are depicted in Table I. The fuel burnup by assembly is shown in Figure 1. There were no degassing operations during the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> period prior to the time of the first sample in which the limit was exceeded.

The root en :s of the evcat is considered to be cladding defects in ene or more fuel rods from second cycle Core XVIII Exxon Nuclear Fuel Company fuel assemblies. No immediate corrective actions are planned.

The second cycle fuel will be removed during the Core XVIII-XIX refueling scheduled for May 1987.

Similar events have been reported under LERs 77-5, 78-03, 78-19, and 78-23. There was no adverse effect on the health and safety of the public as a result of this event.

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TABLE I  :

Specific Acitivities (uCi/ gram)

DATE/ TIME lECE Let-down DE I-131 I-131 I-133-Flow (GPM) 5/31/86 0100 600 to 24 7.61E-2* 1.32E-2* 1.18E-l*

to 6/1/86 2033 598 6/1/86 2034 0 18 - - -

(Reactor Scram) 6/1/86 2330 0 26 5.07E 3.68E-1 3.91E-1 6/2/86 0110 0 26** 1.35E0 1.03E0 9.39E-1 6/2/86 0310 0 48 1.28E0 9.96E-1 8.59E-1 6/2/86 0515 0 44 1.03E0 8.10E-1 6.64E-1 6/2/86 0800 0 46 7.49E-1 6.'04E-1 4.48E-1 6/2/86 1030 0 42 5.66E-1 4.61E-1 3.24E-1 h!kE j $*

a R,

• Determined 5/31/86 at 1025 EDST S 4.

• • Increased to 48 GPM on 6/2/86 at 0130

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. .o Pg. 4 of 4 m aEE CDRE XVIII LER 86-005 TOTAL #aSEMBLY BURNUP (PWD/MTU) TO THE END OF MAY, 1936 01 E1 F1 G1 3264. 4275 4501 3313 C2 D2 E2 F2 G2 H2 4143 6288 17560 6992 6384. 4092 93 C3 03 E3 F3 G3 H3 J3 4154 6603 15851. 17195 23134 23335- 6656 4135 A4 84 C4 04 E4 F4 G4 H4 J4 K4 3478 6468 23191 16304. 16860 18765 16565 16758 6483 3344 A5 B5 C5 05 E5 F5 G5 H5 J5 K5 4641. 7227 23S64. 18937 23525 23003 15726 18172 17745 4526 A6 B6 C6 06 E6 F6 G6 H6 J6 K6 4423 16229 18538 16405 23437, 23360 18938 23802 7256 4602-A7 87 C7 07 E7 F7 G7 H7 J7 K7 3164 6119 18755 16348 18711 16542 15582 22815 6486 3545-B8 C8 D8 E8 F8 G8 H8 JB 3918 6347. 23082 23748 18168 18705 6627 4225 C9 D9 E9 F9 G9 H9

3909 6222 6986 17996 6440. 4239 I

l D10 E10 F10 G10 I 3308 4451 4368 3422 1

l CORE A','ER AGE BUPNUP (NWD/MTU) 11890 FEADY.

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