ML20235K182

Special Rept 87-09:on 870911,RCS Specific Activity Exceed 1.18 Uci Per G Dose Equivalent I-131.Caused by Release of Radioactive Idodine from Known Fuel Cladding Defects.Fuel Assemblies Will Be Ultrasonically Tested for Defect

ML20235K182
Person / Time
Site:	Callaway
Issue date:	09/28/1987
From:	Blosser J UNION ELECTRIC CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
87-09, 87-9, ULNRC-1626, NUDOCS 8710020266
Download: ML20235K182 (4)

Text

• .i a-  !

Etscraic \

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. Callaway Plant i

. September 28, 1987

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-1 U.' S. Nuclear Regulatory Cotmnission  ;

Document Control Desk- l Washington, DC 20555' -

ULNRC-1626 i

Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 87-09 REACTOR COOLANT SPECIFIC ACTIVITY IN EXCESS OF TECHNICAL SPECIFICATION 3.4.8 LIMITATION The enclosed Special Report is submitted pursuant to Technical Specification 3.4.8 and 6.9.2 concerning Reactor Coolant specific activity in excess of Technical Specification limitations.

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LU J. D. Blosser Manager, Callaway Plant TPS/ PSP:jll l l

Enclosure cc: Distribution attached l

1 1

87i0020266 870928 TT PDR ADOCK 0500063 g PDR pS M Mailing Address

• P.O Box 620, Futton, MO 65251 tll

i cc distribution for ULNRC-1626E Mr. A. Bert Davis Mr. Thomas Alexion (2. copies)

Regional Administrator Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission U..S. Nuclear Regulatory Commission Region III 7920 Norfolk Avenue "

799 Roosevelt Road Mail Stop P-316 Glen Ellyn, IL 60137 Bethesda, MD 20014 1 American Nuclear Insurers Mr. 0. Maynard c/o Dottie Sherman, Library Wolf Creek Nuclear Operating Corp.

The Exchange Suite 245 P. O. Box 411 270 Farmington Avenue Burlington, KS 66839 Farmington, CT 06032 Mr. Merlin Williams Manager, Electric Department Supt. of Regulatory Quality & j 4

Missouri Public Service Commission Administrative Services-Office of Inspection & Enforcement Wolf Creek-Nuclear Operating Corp.

P. O. Box 360 P. O. Box 411 Jefferson City, MO 65102 Burlington, KS 66839 I

Records Center Institute of Nuclear Power Operations j Suite 1500 1100 circle 75 Parkway Atlanta, GA 30339 l

NRC Resident Inspector D. F. Schnell (400)

R. J. Schukai (470)

G. L. Randolph

! J. F. McLaughlin J. E. Davis (Z40LER)

(Z40SR) (w/c)

W. R. Campbell F. D. Field (480)

A. P. Neuhalfen A. C. Passwater/D. E. Shafer/D. J. Walker (470) i G. A. Hughes I

Z170.05 (QA Record)

J. M. Price B. L. Allen M. E. Taylor H. Wuertenbaecher, Jr. (100)

S. L. Auston (470)(NSRB)

S. J. Bellers/J. D. Schnack JDB Chrono 3456-0021.6 3456-0260 Z40ULNRC A160.761 N. Date (Sandra Auston) (470) l

i SPECIAL REPORT 87 REACTOR COOLANT SPECIFIC ACTIVITY IN EXCESS OF TECHNICAL SPECIFICATION 3.4.8 LIMITATION l

4 This Special Report is' submitted pursuant to Technical Specification (T/S) 3.4.8 and 6.9.2 because the Specific Activity of the Reactor Coolant. System (RCS) exceeded 1 microcurie per gram (pCi/g) Dose' Equivalent I-131.

At 0100 CDT on 9/11/87, the. Dose Equivalent I-131 of the RCS was found'to be 1.18 pC1/g following a reactor shutdown to commence the plant's second refueling. Action was taken to reduce-the Dose Equivalent I-131 by providing maximum cleanup flow (120 gpm) through the Chemical Volume and Control System mixed bed demineralized. Technical Specification 3.4.8 action statement, applicable to Mode _1, 2, 3, 4, and 5, was entered as follows:

"With the specific activity of the reactor coolant greater than 1 microcurie per gram DOSE EQUIVALENT I-131 or greater than 100/E microcuries per gram of gross radioactivity, perform.the sampling-and analysis requirements of Item 4.a) of Table 4.44 until the specific activity of the reactor coolant is restored to within its limits . . ."

Appropriate sampling and analysis requirements were performed until 0904 on 9/11/87, at which time the RCS specific activity was restored within limits.

The root cause of the event is attributable to the release of radioactive iodine from known fuel cladding defects.

The fuel assemblics will be ultrasonically tested during refueling to identify fuel cladding defects.

Information required by Tech Spec 3/4.4.8 is provided below,

a. Reactor power history is as follows:

From 9/9/87 0100 CDT to 9/9/87 1455 CDT, reactor power was 82%.

From 9/9/87 1455 CDT to 9/10/87 1200 CDT, reactor power was 81%.

From 9/10/87 1200 CDT to 9/10/87 2023 CDT, reactor power was reduced from 81% to 0% at a rate of 10% per hour.

Reactor power remained at 0% from 9/10/87 2023 CDT to 9/11/87 0904.

b. The results of the isotopic analysis for radiciodine are:

E Date Time DEI-131 I-131 I-132 I-133 I-134 I-135 (pci/g) (pci/g) (pci/g) (pC1/g) (pC1/g) (pC1/g) 9/10/87 2243 .868 .693 .290 .530 .015 .262 9/11/87 0100 1.179 .971 .281 .648 .003 .268 9/11/87 0300 1.197 1.002 .242 .621 .000 .224 9/11/87 0530 1.037 .880 .198 .508 .000 .150 9/11/87 0904 .497 .430 .106 .218 .000 .050

c. The cleanup flow through the Chemical Volume and Control System mixed bed demineralized was at 120 gallons per minute (gpm) for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to exceeding 1 pCi/g DEI-131. The cleanup flow remained at 120 gpm while the DEI-131 was above 1 pC1/g.

d. The Volume Control Tank was on a continuous vent of 0.7 cubic feet per minute for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the DEI-131 exceeding 1 pCi/g. A Volume Control Tank purge was also performed on 9/10/87 at 1701 and on 9/11/87 at 0345 and at 0813. These are the only degassing operations that occurred.

e. The DEI-131 exceeded 1 pCi/g for 8.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from 0100 to 0904 CDT on 9/11/87.

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