ML20154C640

Annual Operating Rept 1985

ML20154C640
Person / Time
Site:	University of Illinois
Issue date:	02/26/1986
From:	Bradley Jones, Pohlod C, Stubbins J ILLINOIS, UNIV. OF, URBANA, IL
To:	NRC
References
NUDOCS 8603050279
Download: ML20154C640 (7)

Text

University of Illinois Nrcl2cr EngiIeering Programs at Urbana-Champaign 214 Nuclear Engineering Laboratory 217 333-2295 103 South Goodwin Avenue Urbana lilinois 61801 February 26, 1986 Director Division of Reactor Licensing U.S. Nuclear Regulatory Consnission Washington, D. C.

20555

SUBJECT:

ANNUAL REPORT, Illinois Advanced TRIGA Reactor License No. R-115 Docket No.

50-151 The following is written to comply with the requirements of Section 6.7.f. of the Technical Specifications and the conditions of Section 50.59 of 10 CFR. The outilne of the report follows the numbered sequence of Section 6.7.f of the Technical Specifications.

Yours truly, YA Craig S. Pohlod, Supervisor, Reactor Operations V) W 4 1 )Y)i L<4 James F. Stubbins, Chairman, Nuclear Reactor Committee

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_ Barclay G. p es,Ac @ Chairperson Nuclear EngTneering Trogram cc. Region ill, Office of Inspection & Enforcement USNRC

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ANNUAL REPORT January 1, 1985-December 31, 1985 ILLIN0IS ADVANCED TRIGA Facility License R-ll5 1.

SUMMARY

OF OPERATING EXPERIENCE A. Summary of, Usage The reactor was scheduled for usage an average of 20.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> per week and was in operation an average of 13 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per week.

This was a decrease of about 19% compared to the previous year. The change was due to a smaller than usual number of H.E. 351 students in the fall and a lull in operator training activities due to a reorganization at Braidwood and anticipation of fuel loading at Clinton, in the following table, the percent of time for dif ferent purposes is given. Scheduled time is that reserved for a given oparation, while operating time is from start up to shutdown.

CATEGORY Scheduled Operational Research Projects 4.34 4.54 I rradia tions (Samples) 42.0%

53.6%

Education and Training 47.4%

39 5%

Maintenance and Measurements 6 3%

2.4%

Presently there are two Individuals with Senior Operator Licenses and one individual with an Operators License. Additionally there is one individual who will take a Senior Operators Exam in January 1986. The facility operates with a 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> work week and the equivalent of two full time operators and a reactor health physicist.

I B. Performance Characteristics 1.

Fuel Element Length and Olameter Measurements l

These checks were made on the elements in the B & C hexagonals during the month of March. There were 8314 pulses at the time of the checks. For the 18 olements in this region, there was a slight decreace in the length (2.0 mils).

The accuracy of a given measurement is estimated at d; 5 mils. There was no change in the diameter checks.

The number of pulses in 1985 was 162, bringing the total since 1969 to 8,428. The values for pulse height, reactor period and fuel temperature were the same as that measured in previous years.

2. Reactivity Control Rods: The measured reactivity values of the control rods have shown essentially no change.

Vorlations between sucessive measurements are seldom greater than 5%.

/.

2 Core Reactivity: The loss of reactivity, attributed to fuel burn-up was $0.19 for the year. This value is determined by a comparison of the cold critical xenon-free control rod position at the beginning and at the end of the y

year. Based on an estimated 2c per MW-day of operation, the loss would have been

$0.14.

11. TABULATION OF ENERGY AND PULSING A. Hours Cri tical* and Energy Type of Operation Time (hrs)

Energy (MW-hrs) 0-10 kilowatts 262.3 0.1 10-250 kilowatts 106.9 18.4 250kW - 1.5 MW 221.3 144.7 Pulsing 61.6 1.1 Total 652.1 164.3 B. Pulsing Pulse Size Number

$1.00- 1 70 0

1 71-2.00 12 2.01-2.30 0

2.31-2.90 13 2.91-3 19 137 Above $ 3 19 0

TOTAL 162

• Because of the type of operation, the Hours Critical time includes Instances where the reactor is not critical in the normal sense. These include the time to get critical during a start-up, the time between pulses during continuous pulse operation and short periods during sample irradiations when samples may be removed or added.

Ill. REACTOR SCRAMS l

There were 31 unplanned scrams and no emergency shutdowns.

These scrams were attributed to:

Instrument Malfunction (3); Operator Error (22); and External Causes (6).

The following 15 a summary of the scrams that occurred in 1985 Linear Power (16)

This is a power level scram required by the Technical Specifications. It occurs when the signal on any power range exceeds about 106'4 of that range. Almost all of the scrams (14) occurred when operator tralnees turned the range switch in the vrong direction or placed the mode switch in automatic at too low a power level.

One scram occurred when the chart recorder pen failed to respond to increasing power due to fo. ling of the chart motor dial cord. One scram occurred when a potentlo-meter in the automatic control circuit failed and caused the Regulating Rod to l

drive out.

l

3 Period Scram (9)

This scram is not required by the Technical Specifications. It occurs when the period is 3 seconds or less with the reactor in the automatic or steady state mode.

At the present time the log N chamber has a low impedence on the signal lead to ground. At very low currents this appears as a loss of signal. When the signal appears it comes as a step Increase which triggers the period scram. To avoid this scram, the period circuit must be blocked until the step increase has occurred. Although this could be considered an Instrument Halfunction, it is classified as an operator error because the operator has failed to take the necessary action to block the signal until the step increase has occurred. Eight Period Scrams occurred due to this problem. One scram occurred to to mis-adjust-l ment of the period limitor in the automatic circult.

Fuel Temperature (1)

)

2 This scram occurred due to Radio Frequency noise generated in a piece of test equipment which was energized near the fuel temperature module.

Loss of Power (5)

The unusually large number of loss of power. scrams was due to unscheduled and/or unannounced momentary power shifts due to preparations for installation of a super computer facility near the Nuclear Reactor Laboratory.

IV. Maintenance it is estimated that 300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> (25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> per month) were spent on maintenance during 1985. However, only 67 of these hours are given la the Summary of Operations.

In these cases, a scheduled operation was delayed due to a malfunction of a required instrument or from repairs necessary to 01erate the reae. tor. The sig-nificant items of maintenance are given below.

l Reactor Laboratory Service Air System: This system provides air for the Fast i

and Adjustable Transient Control Rods, Primary isolation Valves, Secondary Diverting Valve, Primary and Secondary d/p Cells,and the seal around the Reactor Bay Truck Door. The actuators for the Truck Door were cleaned, all aluminum tubing was j

replaced with copper tubing, a filter and drain were added upstream of the Truck l

Door and a service air outlet was added to the shop area beneath the Reactor I

Control Room. The aluminum tubing had begun to pit and leak due to earlier problems l

with the system air dryer allowing moisture upstream into the tubing.

Thru-Beam Port: This beam port was made from elght inch diameter aluminum tubing and has become distorted over the years, it is oval in the cross-sectional view rather than circular. This created a problem getting the shielding out for i

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for experiments and installation of experimental equipment. This distortion is thought to be due to a small amount of water seepage into the shield from the reactor tank. This water migrates into the expandable grout used to set the beam port in place.

A carbon steel sleeve or liner was placed in each end of the Thru-Port. A seal has been placed between the carbon steel liner and the original aluminum tubing. The shielding plugs for each end of the port were machined down and new plumbers plugs are being fabricated for the seven inch diameter port. it is thought that the Insertion of the carbon steel liner will hold the shape..of the port. The inner portion of the port which has a six inch diameter is unaffected by this j

action.

Continuous Air Monitor (CAM): As indicated in last year's report, the CAM was a frequent source of difficulty. In May two used CANS were installed. These units were donated to the University of lilinois by Conrnonwealth Edison Co.

f The units, both Eberline Model AMS-2, are capable of replacing the previous unit.

The old CAM was a Nuclear Measurements Corp. Model AM-2A manufactured in 1959. An Eberline was substituted directly for the NMC AM-2A. It (Eberline) provides for 1

automatic operation of the ventilation damper, directing exhaust air to a bank of charcoal filters in the event of an alarm.The second unit has been installed I

at the top of the reactor tank. Presently this unit is used for alarm and indication functions.

(-) 25 VOC Console Power Supply: In a continuing effort to reduce noise in the control console electronics, capacitors in the (+) and (-) 25 VDC power supplies were checked. A leaky capacitor was identified in the negative supply. It was j

replaced and all capacitors associated with the negative supply voltage distribution were checked. A bad capacitor was also identified in the Primary Flow Scram Bi-l stable Circuit. Replacement of this capacitor corrected an intermittent problem with noise induced actuation of the Primary Flow Scram Bistable. The Primary Flow Scram is not required by Technical Specifications.

Exhaust Stack Radiation Monitor Several difficultles were encountered with f

the Stack Monitor. These were unrelated items which caused a common problem. The Stack Monitor began to record excessive counts. Attempts to generate a voltage plateau curve for the Stack Monitor G.M. detector failed. The GM tube was replaced.

It was no possible to generate a voltage plateau curve for the GM tube but the occasionally the Stack Monitor would alarm. Further investigation turned up a bad connector in the alarm portion of the monitor. The connector was replaced.

This monitor is required by Technical Specifications and the reactor was, not eperated while it was out of service. No attempt was made to subtract out counts

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5 from the argon calculations due to excessive counts from the Stack Hunitor.The actual release of argon for the year is less than indicated in Section VI.

V.

CONDITIONS UNDER SECTION 50.59 of 10CFR There were no changes to the system or in the procedures in 1985* All procedures and plans will be reviewed in 1986. Three new experiments were run in 1985 All of these are variations of previously done experiments. All were run at least once in 1985.

One of these experimentsused a pulse from the reactor to form excimer states in rare gas-halogen mixtures for the study'of formation mechanisms. It was a variation on nuclear pumped laser experiments of the past.

The second new experiment was actually just a more sophisticated system for doing neutron scattering work with crystalline and amorphous ma'terials. This experiment involved measuring multi-axial scattering. Previous experiments utilizing the Thermal Column have looked a unlaxial scattering.

The third new experiment substituted a surface barrier detector in place of the target for the purpose of developing a method for in-situ measurements of g raphi te erolslon and re-deposition in fusion devices.

It uses a surface barrier detector for the porpose of determining the thickness of a foil.

Wi th each experiment evaluations of radiation hazards procedures for making changes to the experiment and shleiding requirements for the experiment were reviewed and found to be satisfactory.

• USNRC accepted the previously submitted Radiation Emergency Plan and it was implemented and' reviewed by the Nuclear Reactor Committee in July of 1985 VI.

Release of Radloactive Materials

~0 Argon -41:

Ave. Concentration to environs via exhaust = 2.22x10 pCl/ml.

Total release-665 mcl Monthly range = 19-125 MCI Tritic7:

Estimation of 1 mCl release from evaporation of water In the reactor tank. This is based on measured concentrations of H and water usage for the year Ef fluent to sanitary sewer:

Less than 0.2 pCl.

Vll. ENVIRONMENTAL SURVEYS There were no environmental surveys in 1985. Contamination surveys are made in the Laboratory. See Section Vill.

Vill. PERSONNEL RADIATION EXPOSURE AND SURVEYS WITHIN THE FACILITY Seventeen persons were assigned film badges at the facility. Four were full-time employees, while the others averaged less than 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> per week. The badges are sent to Radiation Detection Company of Sunnyvale California on a monthly basis. The table below gives the wnole body gamma dose recieved by those who were

6 assigned film badges.

Dose (REMS)

Number of Individuals No Measurable Exp.

7 0.01- 0.10 9

0.10- 0.25 1

Above 0.25

__0, _,

Total 17 Th= highest Individual dose was 180 millirems. This was recleced by the Reactor Healtn Physicist who handles radioisotopes that are produced and performs calibrations on radiation monitoring equipment. No other Individuals recieved doses above 100 millirems.

Individual doses to students and visitors as recorded on self-reading dosimeters were less than 10 millirems.

Contamination Surveys Smear samples from 34 locations in the laboratory are taken at periodic Intervals.

The removable beta contamination is determined by checking the samples with a gas flow proportional counter.

The maximum contamination is in the vicinity of the tubes from which irradiated samples are removed. There were 1,660 samples irradiated during the 2

year.

In the sample area, the contamination varied f rom 46-15,932 dpm/100 cm

~7

-5 2

or 2.1x10 to 7 2x10 pCl/cm. In the control room area the maximum was 170dpm/100cm

~7 2

or 7.6x10 pCl/cm.

Smears f rom other areas in the laboratory showed a maximum

-5 2

of 2443dpm/100cm or 1.tx10 uCI/cm,

IX.

Nuclear Reactor Commlttee Dr. James F. Stubbins was re-appointed as Chairman of the Nuclear Reactor Committee for the 1985-1986 term. He is a Professor of Nuclear Engineering and has been a member of this committee previously. Dr. A.M. Ougouag, ASST. Prof of Nuclear Engineering was also re-appointed to the committee as was the University Health Physicist. The following changes to the committee were made in 1985:

1. Dr. Bradley J. MicNilch, ASST Prof of Nuclear Engineering replaced Dr. David Ruzic, ASST Prof of Nuclear Engineering.

2. Mr. Craig S. Pohlod, Supervisor, Reactor Operations was added to replace Mr. Gerald P. Beck who retired at the end of August. Mr. Beck served very ably as Reactor Supervisor f rom 1960 through August of 1985

3. Mrs. Elizabeth Thompson was addedte the committee to replace Mr. David Krueger, who was acting Reactor Health Physicist. Mr. Krueger lef t the University of Illinols in the fall of 1985. Mrs. Toompson is a member of the Nuclear Engineering Program Staf f.