ML18219C205

Licensee Event Report RO 50-315/00-000 Re Dose Equivalent Iodine-131 Activity in Reactor Coolant System

ML18219C205
Person / Time
Site:	Cook
Issue date:	04/04/1978
From:	Shaller D Indiana Michigan Power Co
To:	James Keppler NRC/RGN-III
References
Download: ML18219C205 (13)

Text

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REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS>

DISTRIBUTION FOR INCQmING MATERIAL 50-3i5 REC: KEPPLER J G ORG: SHALLER D V DOCDATE: 04/04/78 NRC IN 8. MI PWR DATE RCVD: 04/1 1/78 DOCTYPE: LETTER NQTARIZED: NO COPIES RECEIVED

SUBJECT:

LTR 1 ENCL i LICENSEE EVENT REPT (RO 50-315l00-000> ON 03/07/78 CONCERNING UNIT 1 REACTOR TRIPPED FRON i00/ P4JR AND DOSE EQUIVALENT IODINE-131 ACTIVITY IN UNIT i REACTOR COOLANT SYSTEM WAS FOUND OUT OF SPECIFICATION... W/ATT SUPPORTING INFO.

PLANT NAME: COOK UNIT 1 4+w4+++4+w+~4Hs~++ DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS REVIEWER DISTRIBUTOR INITIAL: X JH INITIAL: ~

INCIDENT REPORTS N (DISTRlBUTION CODE A002>

FOR ACTION: BR CHIE ENCER++W/4 ENCL INTERNAL: REG FILE++W/ENC' NRC PDR+wW/ENCL MIPC~~W/3 ENCL SCHROEDER/I PPOL I TQ4H~W/ENCL HOUSTON+4W/ENCL NOVAK/CHECK+~W/ENCL'NIGHT++W/ENCL EEB++W/ENCL BUTLER4~+W/ENCL HANAUER+44J/ENCL TEDESCO+4W/ENCL E ISENHUT++W/ENCL BAER~~W/ENCL SHAQ~~~W/ENCL VOt LNER/BUNCH++W/ENCL KREGER/J. COLLINS4~+W/ENCL ROSA~~W/ENCL

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fh ED April 4, 1978 CO Operating License DPR-58 Docket 8 50-315 Nr. J. G. Keppler, Regional Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Corrmission Region III 799 Roosevelt Road Glen Ellyn, Il 60137

Dear Nr. Keppler:

This report is submitted persuant to the requirement of Appendix A Technical Specification 3.4.8 and 6.9.1. On t1arch 7, 1978, the dose equivalent iodine-131 activity in Unit 1 reactor coolant system was found out of specification.

At 1003 on tiarch 7, 1978 Unit 1 reactor tripped from 100K power.

Immediately following the trip, letdown purification flow was increased to its maximum. Analysis at 1130 on March 7, 1978, indicated dose equivalent iodine-131 at 1.025.)1Ci/cc, f1aximum dose equivalent iodine-131 concentration was detected at 1345 to be 1.046 pCi/cc*. Dose equi-valent iodine-131 remained .out of specification until 1440. All ad-ditional sample analysis indicated the reactor coolant dose equivalent iodine-131 remained in specification and was decreasing. No additional spi king was noted during the subsequent reactor startup. Ho degassing operations were associated with this event.

Iodine release at this time period is consistent with data reported in Westinghouse Electric Corporation WCAP-8637, "Iodine Behavior under Transient Conditions in the Pressuirzed Water Reactor". Dose equivalent iodine-131 values were in the "Acceptable Operation" portion of Technical 7e 10200

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Apri 1 4, 1978 Mr. J. G. Keppler Page Two Specification Figure 3.4.1 at all times during the transient. Fuel burnup by core region and all additional data is indicated in the attached table/graphs.

• Coolant samples are brought to ambient conditions prior to counting, therefore, units of pCi/g and pCi/cc are considered interchangeable.

Very truly yours,

+a~ D. V. Shaller Plant Manager attachments cc: R. W. Jurgensen J. E. Dolan R: Kilburn R. F-.. Kr'oeger R. J. Vollen, BPI K. R. Baker, RO: III P. W. Steketee, Esq.

R. C. Callan R. Walsh, Esq.

G. Olson J. Stietzel PNSRC File G. Charnoff, Esq.

J. M. Hennigan Dir, IE (ZO copies)

Dir, MIPC (2 copies)

~ MARCH 7, 1978 UNIT NO. 1 CYCLE NO. 2 Fuel Burnup by Cor e Reoi on REGION NO. BURNUP CUMULATIVE ENERGY CUMULATIVE FOR PERIOD BURNUP FOR PERIOD ENERGY (teDr MTU) (MHD/MTU) (BTU) (BTU) 0.1871E+04 0.9543E+04 0.4267E+13 0.2176E+14 0.1799E+04 0.2802E+05 0 '290E+13 0.668lf+14 0.2053E+04 0.2397E+05 0.4867E+13 0,5685E+14 CORE TOTAL 0.1908E+04 0.2067E+05 0.1342E+14 0.1454E+15

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