ML20034E906

Annual Rept 1992 Illinois Advanced Triga Reactor

ML20034E906
Person / Time
Site:	University of Illinois
Issue date:	12/31/1992
From:	Hang D, Holm R, Bradley Jones ILLINOIS, UNIV. OF, URBANA, IL
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9303020066
Download: ML20034E906 (10)

Text

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University Of Illinois Department of College of Engineering Nuclear Eagineering at Urbana-Champaign 214 Nuclear Engineering 217 333-2295 Laboratory 217 333-2906 fax 103 South Goodwin Avenue Urbana.IL 61801-2984 February 22, 1993 Docket No. 50-151 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station F1-137 Washington, DC 20555

SUBJECT:

ANNUAL REPORT: Illinois Adsanced 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 10CFR50.59.

The outline of the i3 port follows the numbered sequence of section 6.7.f of the Technical Specifications.

Sincerely, l

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' Richard L. Ifo'Im

Reactor Supervisor lDL AA< Q Daniel F. Hang j

Reactor Laboratory Director A

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s BarclayG.JMes,1[%d Department di Nuclear Engineering ec: Regional Administrator, Region III, USNRC Nuclear Reactor Committee File 9303020066 921231 (I

PDR ADOCK 05000151 7/)fr i

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Page 2 STATE OF ILLINOIS COUNTY OF CHAMPAIGN t

Richard L. Holm, being first duly sworn on oath, deposes and says that he has affired his signature to the letter above in his official capacity as Reactor Supervisor, University of Illinois Nuclear Reactor Laboratory; that in accordance with the provisions of Part 50, Chapter 1, Title 10 of the Code of Federal Regulations, he is attaching this affidavit; that the facts set forth in the within letter are true to his best information tsud belief.

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Richard L. Holm Reactor Supervisor Subscribed and sworn to before me, a Notary Public, in and for the County of Champaign, State of Illinois, this A A day of 7e/w A.D., 1993.

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$-lVfh2 VTll 1 0 r1 Solary Public of lin My Commission Expires

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" OFFICI AL SE AL "

l K ATHLEEN M. DYS ART NOTARY PL'BUC. STATE OF ILUNCIS b Mf COMMISSION EXP;RES En9/95 J

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Page 3 ANNUAL REPORT JANUARY 1, 1992-DECEMBER 31,1992 ILLINOIS ADVANCED TRIGA FACILITY LICENSE R-115 1.

SUMMARY

OF OPERATING EXPERIENCE A.

Summary of Usage During 1992 the reactor was operated an average of 19.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> per week.

This is up from 16.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per week in 1991.

This increase is primarily due to an increase in research related to neutron activation analysis.

i As a percentage of total operating time education and training decreased over 1991 (10.1 vs 27.6) as no power plant operator training was conducted in 1991. Maintenance & Measurements were up in 1991 due to full core fuel measurements and some measurements performed in preparation for installation of the digital console.

CATECORY PERCENT OF OPERATION Research Projects 14.3%

Irradiations 66.3%

i Education & Training 10.1%

Maintenance & Measurements 9.3%

Presently there are two individuals with a Senior Operator License and two individuals with an Operators license.

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 /> week schedule, a staff of two full time equivalent operators and

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one full time reactor health physicist.

B.

Performance Characteristics 1

1.

Fue] Element Length and Diameter Measurements l

These checks were made on the entire core during the month of l

February. The pulse number at the time of the checks was 10,665.

For the one hundred and seven elements in the core at this time, there was an average increase in the length of about 8.4 mils. The accuracy of a given measurement is estimated at i5 mils. There was no change in the diameter of the fuel elements checked.

There were 247 pulses.in 1992, bringing the total since 1969 to 10,898.

For a standard $3.00 pulse, the values for pulse height, reactor period and fuel temperature were the same as measured in previous years.

2.

Reactivity Control Rods: The measured reactivity values have not changed significantly due to fuel insertions and movements. The relative worth of each rod maintaining approximately the same worth as previous values.

Core Reactivity: The net loss of reactivity attributed to fuel burnup

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Page 4 during the year was $0.63.

This value was determined by a comparison of the cold critical xenon-free control rod position at the beginning and at the end of the year and correcting for core reactivity gained by the addition of fuel during the year. Two fuel elements were added in May which resulted in a net reactivity gain of $0.68.

Based l

on an estimated 2 ( 0.5) cents per MW-day of operation, the reactivity loss for the year would have been approximately $0,59.

II.

TABULATION OF ENERGY AND PULSING A.

Hours Critical *- and Enerfy Type of Operation Iime(hrs)

Energy (MW-brs)

O - 10 kw 216.0 0.03 10.1 kw - 250 kw 120.3 16.0 250.1 kw - 1.5 MW 628.0 688.9 l

Pulsing 1.9 Total 964.3 706.83 B.

Pulsing l

Pulse Size Number

$1.00-1.70 3

l 1.71-2.00 35 2.01-2.30 0

2.31-2.80 4

9.81-3.19 203 Above $3.19 2

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Total 247

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• Because of the type of operation, the Hours Critical time includes the time during continuous pulsed operation between pulses when the reactor is not critical in the normal sense.

Since pulsing operation is done from less than 1 kw the time spent pulsing is inclusive of the time spent in the 0-10 kw category.

III. REACTOR SCRAMS l

There were 21 unplanned scrams and no emergency shutdowns during this time period.

These scrams were attributed to Instrument Malfunction (13), Operator / Operator Trainee Error (6) and External Causes (2). This is fewer than average for the facility over the past several years.

r Linear Power (8): This is a power level scram required by the Technical Specifications.

It occurs when the signal on any linear power range exceeds about 108% of that range. Seven (7) of these scrams were due to electronic noise problems.

As this noise is intermittent and irregular it has not been possible to positively identify the source. One (1) of these scrams was due to operator error in that the operator did not uprange before the scram setpoint was exceeded.

Period Scram (4): This scram is not required by Technical Specifications.

It occurs when the period is 3 seconds or less with the Mode Selector Switch in Automatic or Steady State position. All four (4) of these l

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r Page 5 scrams occurred due to electronic noise.

As in the linear channel, this noise is intermittent and irregular.

Percent Power (2): This is a power level scram required by Technical Specifications.

It occurs when the signal exceeds about 108% of rated power.

Both of these scrams occurred due to electronic noise. As in the linear channel, this noise is intermittent and irregular.

Primary Flow (5): This scram is not required by Technical Specifications.

The scram occurs if power level exceeds 1.0 MW without adequate coolant flow (approx. 550 gpm) in the primary coolant loop.

This scram will also occur when adequate secondary flow (approx. 900 gpm) is not available and j

power is greater than 1.0 MW.

One (1) of these scrams occurred due to i

the operator failing to establish adequate secondary cooling flow prior to exceeding 1.0 MW.

Two (2) of these scrams were due to difficulty in maintaining secondary flow while starting up the secondary system in j

winter line-up.

The on-service cooling tower is drained until needed if the air temperature will be excessively low.

Refilling the cooling tower j

sometimes leads to the introduction of air to the system. This in turn I

can cause the secondary flow switch to trip and initiate a scram if power l

is above 1.0 MW.

Two (2) of these scrams occurred due to l

operator / operator trainee error during a laboratory exercise in natural l

circulation where the power level was allowed to exceed the 1.0 MW flow trip setpoint.

External Causes (2): One (1) scram was caused by a momentary loss of power due to an electrical storm.

One (1) scram was caused by i

accidentally securing control power to the cooling pumps while at power l

greater than 1.0 MW.

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IV.

MAINTENANCE It is estimated that about 520 hours0.00602 days <br />0.144 hours <br />8.597884e-4 weeks <br />1.9786e-4 months <br /> (10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per week) were spent on maintenance related activities. These hours account for time spent carrying out repairs and scheduled surveillance activities.

The significant items of maintenance are given below.

Samnle Handline Tool: The isotope sample handling tool became inoperative and it was necessary to replace the cable and rebuild the rotary operator i

due to fatigue failure of the contact bushings.

1 Chemical Cleaning of the Lazy Susan: The Lazy Susan is the main irradiation facility for the reactor.

It is capable of holding 80 samplc vials and rotating them in a dry condition around the core.

In February the Lazy Susan became extremely difficult to rotate. The normal drive motor was inadequate and extreme physical effort was required to rotate it by hand.

It was decided that the cause of the binding was oil residue in the bearings. On consultation with General Atomics and Oregon State University whom had had the same problem a solution of Simple Green, an organic cleaner, was used to remove the residue.

This procedure worked successfully and the facility has operated fine since then.

1. 1 Cooline Tower Float Switch: The float switch that secures the secondary pump if cooling tower level gets too low was replaced.

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'racerlab Po-r Supolv: The Tracerlab area radiation monitor power supply

- and was replaced.

Y.

CONDITIONS UNDER SECTION,50.59 0F 10CFR50 There were two reviews carried out in 1992 under 10 CFR 50.59.

50.59 Review of Primary Water Heater System:

This system utilizes an immersion heater 'nstalled in the auxilary cooling system to make up for heat losses in the primary pool during an extended shutdown to prevent tank temperature from dropping excessively low.

The only modification necessary to the system was the removal of a :leanout plug at a pipe elbow to install the heater. Safety circuit.. were installed to secure power to the heater if flow in the auxilary cooling system were lost.

50.59 Review for Installation of Capacitive Pool Level Continuous Monitor and Float Switches for Level Control and Scram Capability: The present continuous level monitor is a Yarway system with a scram backup in the form of a float switch. The proposed system (not installed yet though approved) utilizes a capacitive level monitor that is more accurate and capable of a 4-20 ma output that can be input to the digital control

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console as well as backup float switches.

The new system will utilize the same tank penetrations as the Yarway system and reduce the need for some external piping.

VI.

RELEASE OF RADI0 ACTIVE MATERIALS A. Eassous Effluents

1) Arron-41

a. Average concentration released to the Environs via the Exhaust Stack was 1.8 E-7 uCi/ml.

b. Total activity released was 6,445 mci.

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c. Monthly range of activity released was 120 to 901 mci.

2) Tritium i

a. Estimated release from the evaporation of water in the TRIGA and h0PRA Reactor Tanks was 2.16 mci. This is based on the combined measure of activity of H-3 in each tank divided by the total volume of makeup water additions since the tanks were last sampled (yearly).

B. Liouid Effluent

1) Waste Water

a. Waste Water is collected in the Reactor Building Retention Tank, sampled, and then discharged to the municipal sanitary sewer i

system. The total amount of activity discharged this year was j

1.4 uCi with an average concentration of 3.6 E-7 uCi/ml.

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Vll. ENVIRONMENTAL SURVEYS A. Continuous Radiation Monitoring utilizing Thermoluminescent Dosimeters (TLDs) supplied by a vendor (Landauer, Inc.) was conducted at the Site Boundary and in the surrounding Environs.

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1) Site Boundary The site boundary is established at the Reactor Building Walls with i

extensions at the fence around the Cooling Towers and the perimeter of

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the roof over the Mechanical Equipment Room. This is also defined as j

the boundary between the Restricted and Unrestricted Areas. The average dose at this perimeter in 1992 was 156 mrem with a range of 50 mrem to 310 mrem.

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2) Surrounding Environs l

l The Environs and University Owned Buildings in near proximity to the l

Reactor Building were monitored. The average dose recorded was equal i

L to or less than the Lower Limit of Detection (LLD = 10 mrem). The i

highest Quarterly lacation reading was 30 mrem with occasional

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readings of 10 and 20 mrem, however, the locations varied so no

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adverse trend wae identified.

f VIII. PERSONNEL RADIATION EXPOSURE AND SURVEYS WITHIN THE FACILITY r

i A. Personnel Exposure i

1) Whole Bodv A total of 25 individuals were assigned Film Badges at the facility.

There were 3 full time employees working 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> / week and 5 students working 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> / week. All others averaged less than 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> / week in the facility. The badges are sent to Landauer. Inc.; r National Institute of Standards and Technology (NVLAP) accredited Dosimetry Vendor. The tables and explanations below outline the Whole Body Dose received by all 25 individuals assigned Film Badges at the Reactor Lab in 1992.

Whole Body Dose (mrem)

Number of Individuals No Measurable Exposure (LLD = 10 mrem)

A.

9 B.

0 10 to 100 12 6

> 100 to 250 3

15

> 250-1 1

ManRem Total A. 4.870 b.

1.570 Total 25 25 Table A.

Without Control Badge Readings Subtracted The highest individual Whole Body Doses were 800, 450, 340, and 290 mrem. All of these doses were received as a result of handling radioisotopes and/or experimental devices. The highest dose received was 800 mrem by the Reactor health Physicist who handles most of the irradiated samples removed from the Reactor Core and performs initial i

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t Page 8 surveys on all irradiated experimental devices. The Reactor Supervisor and the Student Assistant to the Reactor Health Physicist received 340 and 290 mrem, respectively, for the reasons noted above.

The individual who received 450 mrem is a researcher in Nuclear Pumped Lasers and received this exposure from handling his ir adiated experimental apparatus.

Note: The dose of record for all individuals is that recorded without the Control Badge Readings subtracted. What follows is an explanation, only, of abnormally high collective ManRem resulting from a little bit of background spread over an entire population of badged personnel.

Iable B.

With Control Badee Readings Subtracted This method of reporting exposure slightly underestimates the exposure for Reactor Staff who are present in the Reactor Building for 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> / week because it subtracts all Ar-41 & background exposure recorded by the Control Badge. However, these individuals are exposed to Ar-41 & background only when they are present, the Ar-41 is present, and the Reactor is operating at a significant power level.

For the rest of the individuals who are at the Reactor infrequently these exposures are more representative of their true dose by not including the Ar-41 & background exposure that their badges recorded when they were not wearing them. The background subtracted was for the relevant time period when that period was less than 12 months.

Remedial Action Dosimetry Storage was changed from.an open rack to a Lead-lined enclosure in mid-December 1992 and the effect on the Control Badge, and thus the background dose recorded when badges are not being worn, has yet to be determined. However, preliminary results are encouraging, for the month of January 1993 the Control Badge reading was 10 mrem indicating a 50% to 67% reduction in the recorded l

background dose. This reduction may be attributable to the use of the l

new Storage Cabinet. In addition, review of exposure records for 1992 l

indicated that there were no background readings on the Control Badge until May. In late April Liquid Waste from the Chemical Decontamination of the Reactor's Rotary Specimen Rack was stored on the floor level below the floor where the Dosimetry is stored.

Although shielded to yield General Area Dose Rates in the immediate vicinity of 2 to 3 mrem /hr it appears likely that this source term contributed on the order of 0.03 mrem /hr, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> / day, 30 days / month causing the elevated background readings. This waste is scheduled for removal from the Reactor Building to temporary storage elsewhere on campus in the near future. Combined with the use of the new Storage l

Cabinet and the addition of approximately 15 tons of shielding on the I

middle level of the Reactor Tank (Biological Shield) to further reduce background dose from Reactor Operation this should eliminate the recording of background dose as if it were actu411y received by l

personnel.

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2) December 1991 Exposure Investigation In last year's report it was noted that two exposures in December 1991, of 340 and 690 mrem, were under investigation. The result of that investigation clearly demonstrated that these doses were

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received when the individuals were not wearing their Dosimetry but i

had improperly stored their badges in the proximity of Radioactive i

Material for an extended period of time. The official records for these individuals were changed and the corrected doses were 100 and 40 mrem respectively.

3) Extremity Exposure i

Due to the same problem with background dose discussed above there are two different ways of looking at Extremity Exposure. The ManRem of record was 18.120 and the ManRem, if the Control Badge could be subtracted, was 12.640. No individual approached within a significant percentage of the Quarterly Limit for Extremity Exposure so no further discussion is warranted.

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4) Skin Dose There were no significant deviations between the Shallow Dose and Deep Dose reported by the vendor for any personnel.

5) Internal Exposure There were no incidents or events that required investigation or assessment of internal exposures. Contamination levels are acceptably low and areas few. There were no evolutions performed or events that occurred that caused, or could have caused, the presence of Airborne Radioactivity.

B. CONTAMINATION SURVEYS Smear surveys from various locations around the laboratory were taken at periodic intervals, routinely and as needed. The removable contamination was determined by counting the smears on an Eberline BC-4 Beta Counter and a SAC-4 Scintillation Alpha Counter.

The maximum gross Beta Contamination was usually found in the j

vicinity where the irradiated sample containers were handled." There were 6565 samples irradiated during the year. In the sample handling vicinity the posted contamination areas had removable activity from 2,000 to 65,000 dpm/100 cm2 In the Control Room area the maximum was 400 dpa/100cm2 Smears from other areas of the laboratory showed a maximum of 5,000 dpm/100cm2 Decontamination of these latter areas always yielded results at levels less than 1000 dpm/100cm2 Surveys for Alpha Contamination were less than or equal to a Minimum Detectable Activity of 17 dpm/100cm2 In July a customer delivered Geological samples to be irradiated for Neutron Activation Analysis. Beta Contamination levels in the i

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l Page 10 mrad /hr range on smears were detected. It was quickly determined that the principle isotope was Na-24 and further investigation revealed that the pre-irradiated samples had become grossly i

contaminated with " Sea Salt" at the researcher's laboratory.

Appropriate decontamination efforts were undertaken at the Reactor Laboratory resulting in acceptable levels of removable contamination and appropriate procedures implemented at the researcher's laboratory to preclude the pre-irradiation contamination of samples with " Sea Salt". These measures have proven to be effective and no further incidents were experienced.

IX.

NUCLEAR REACTOR COMMITTEE Dr. Sheldon Landsberger was appointed Chairman of the Nuclear Reactor Committee for the 1992-1993 academic year.

Dr. Landsberger is an Associate Professor of Nuclear Engineering. He is the head of the Neutron Activation Analysis facility that utilizes the reactor.He hasserved on the reactor committee as a member for several years.

The following members remained on the Nuclear Reactor Committee:

Dr. George H. Miley, Professor of Nuclear Engineering; Mr. Hector Mandel, Campus Radiation Safety Officer; Mr. Richard L. Holm, Reactor Supervisor (ex-officio); Mr. Mark Kaczor, Reactor Health Physicist (ex-officio).

l Dr. Magdi Ragheb,-Associate Professor of Nuclear Engineering, replaced Dr. Dan Cacuci on the committee in the Spring of 1992.

Dr. Ragheb specializes in computational methods, reactor theory, radiation protection and shielding and probabilistic risk assessment.

l Professor Dan Hang replaced John Williams as a member of the committee l

and as interrim Reactor Director in January.

Dr. Williams has resigned his position as Reactor Direcor.

Professor Hang has been affiliated with the reactor facility since its inception and held an operators license on the Mark Il in the early 1960s. Professor Hang specializes in nuclear fuel cycle economics and high voltage electrical transmission, i

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