ML20204F225

Annual Operations Rept for Jul 1985 - June 1986

ML20204F225
Person / Time
Site:	University of Iowa
Issue date:	06/30/1986
From:	Hendrickson R IOWA STATE UNIV., AMES, IA
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8608040128
Download: ML20204F225 (4)

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ANNUAL OPERATIONS REPORT for the Iowa State University UTR-10 Docket No. 50-116 July 1,1985 -- June 30,1986 This is a routine operations report to the Nuclear Regulatory Commission in accordance with Operating License R-59, Appendix A, Technical Specifications, Section 6.6.

1. Summary of reactor coeratino experience includino the eneroY oroduced by the reactor:

The reactor continues to be operated in support of the teaching and research programs of the Department of Nuclear Engineering. Sophomores and juniors are served by direct use of the reactor in three separate tourses offered during fall and spring semesters. Measurements needed in support of research occur normally during the summer, but during the last year, the research effort was concentrated most heavily during the spring.

During the period Sep 24,1985 to Jan 31,1986, the reactor was inoperable due to failures in the inlet coolant temperature channel and moderator level channel power supply. An extraordinary delay in obtaining replacement equipment for the inlet temoerature channel was responsible for the majority of the down-time.

During the reporting period, a total of 40 kilowatt-hours of energy production and 196 hours0.00227 days <br />0.0544 hours <br />3.240741e-4 weeks <br />7.4578e-5 months <br /> of operation were recorded. A percentage breakdown of operations categories is given below:

Research Teaching Maintenance Operator Service Grad U grad Training Energy (%) 13 0 17 57 7 6 Time (%) 22 0 33 7 35 3

2. Unscheduled shutdowns includino, where acclicable, corrective action taken to creclude recurrence:

An unscheduled shutdown on Aug 5,1985, occured during a thermal power measurement at 10 kW. It was caused by an accidental toJch of an instrument lead Annual Operations Report for R-59 ... Page 1 g

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with a tip ja R to signal ground while setting up to take data in accordance with the written neasurement procedure. To prevent recurrence, the eouipment list and measurement step of the procedure were revised to require use of tio-jack leads with most of the tip shaft insulated.

Spurious period scrams wore recorded on Feb 24 and Feb 25,1986. Both trips occured in the same period channel (two channels are provided) during the subtritical phase of startup. The cause was traced to dirty contacts in an Operate-Calibrate switch that was used during the precritical checkout to calibrate the period channel; the switch was not making good contact in the operate position.

3. Major creventive and corrective maintenance coerations havino safety sionificance:

The inlet coolant temperature controller, installed at the time the control console was upgraded in Jul 1971, failed on Sep 24,1985; it and the indicator were replaced with new, functionally equivalent digital equipment. Attempts to repair the old controller unit were unsucessful--even the manufacturer would not work on it af ter the cause of failure was discovered. The new equipment was installed and calibrated so that performance testing could begin on Jan 13,1986.

During the test star, tup to check the function of the new inlet temperature controller on Jan 13,1986, the moderator level channel performance was unsatisfactory. (This channel provides a stram signalif the water levelis too high in the core tanks.) The problem was traced to the power supply for the flow rate, outlet temperature, and moderator level channels. The temperature channel was operable, and the PS was providing sufficient potential for the flow rate channel that normally operates at the lower end of its output range. Only the level channel, operating at 90% of full scale, was affected. After repair of the PS, all channels were re-calibrated. Normal operations began again on Jan 31, 1986.

4. Major chances in the reactor facility and crocedures, and new tests or exoeriments, or both, that are sianificantly different from those oarformed oreviously and are not described in the Safety Analysis Pecort, includina conclusions that no unreviewed safety cuestions were involved:

There were no major changes in the facility, procedures, tests, or experiments.

5. Summary of the nature and amount of radioactive effluents released or discharced to the environs beyond the effective control of the University as determined at er before the coint of such release or discharae (Included, to the extent cractical, are estimates of individual radionuclides cresent in the effluent. If the estimated averaae release Annual Operations Report for R-59 ... Page 2

r after dilution or diffusion is less than 25 cercent of the concentration allowed or recommended, a statement to this eHect is used):

Argon-41: The technical specification limits on release of this radionuclide into the environs are based on weekly (up to 100 kWh) and annual (up to 4760 kWh) energy production of the reactor. The operating records show that much less than 25% of the concentration allowed was released to the environs.

. Others: No measurable amounts of other radioactive effluents were released to the environs.

6. Summarized results of anY environmental surveys cerformed outside the facility:

.No environmental surveys outside the facility were required to be performed since the trigger levele based on surveys inside the facility, was not exceeded.

7. Summary of eXoosures received bY facility oersonnel and Visitors where such exoosures are creater than 25 cercent of that allowed or recommended:

No facility personnel or visitors had exposures greater than 25 percent of that allowed or recommended.

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Annual Operations Report for R-59 ... Page 3

D rn B j Department of Nuclear Engineering 261 Sweeney Hall IOWA STATE ^ r- 5= "

UNIVERSITY Telephone 515-294-5840 PRIORITY ROUTING fjrst g

gg July 25,1986 Y d'h- k-j{'----

E pac HL Q Docket No. 50-116 Director U. S. Nuclear Regulatory Commission - Region III 799 Roosevelt Road Glen Ellyn, IL 60137 j

Dear Sir:

Enclosed with this letter is the Annual Operations Report for the Iowa State UTR-10 research reactor. The period covered is from July 1,1985 to June 30, 1986.

Sincerely, f4A4kNk4w Richard A. Hendrickson l Reactor Manager l

RAH:rh Enclosure cc: Director of Inspection & Enforcement, US NRC L. E. Burkhart, Chm, Radiation Safety Comm.

R. A. Danofsky, Chm, Reactor Use Comm.

E. E. Sobottka, Dir, Environmenta Health & Safety Department j B. I. Spinrad, Chm, Nuclear Engineering Department

'JUL 3 01986

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