ML20114D870

University of Utah Triga Reactor Annual Operating Rept for Period 910701 - 920630

ML20114D870
Person / Time
Site:	University of Utah
Issue date:	06/30/1992
From:	Gehmlich D UTAH, UNIV. OF, SALT LAKE CITY, UT
To:	Mendonca M NRC
References
NUDOCS 9209100091
Download: ML20114D870 (8)

Text

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UNIVERStrY

'OFUTAll 28 August 1992 Document Control Center U.S. Nuclear Regulatory Conunission ~

Washington, D.C. 20555

Dear Sir / Madam:

Enclosed you will find a copy of the Annual Operating Report for the University of Utah TRIGA Reactor, License No. R-126, Docket No. 50-407, for the period 1 July 1991 through 30 June 1992. This report fulfills TRIG A Technical Specilication (~lTS) 6.10(S).

-If you have any questions concerning the report please contact the staff a' the facility.

Sincen ly,

,h hfA.  ? W$ l Dietrich K Gehmlich E Reactor Administmtor College of Digineering g g 4 4 gj Of te .>f the %n g

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The Universitly of UtahReport Annua Operating TRIG A Reactor .

for the period l 1 July 1991 through 30 June 1992  :

A. NAIGATIVE.

1. Operating Experience.  !

The University of Utah Nuclear Engineering Laboratory (UUNEL) TRIGA Reactor.

License No. R 126. Docket No. 50 407, was critical 150.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> and generated 7599.1 ,

kilowatt hours of thennal energy during this reporting year. The reactor was used for educational demonstrations, laboratory experiments, systems tests, power measurements ,

and sample irradiations.

i

2. Chanites in Facility Design i

The TRIG A Control System Upgrade Program is still in progress as of this reporting date.

A new three-channel strip chart recorder was install:d in the contro? cormle in March 1992. The recorder now displays the imear and percent power channels and the readout from the continuous air monitor. The lilM Series /l computer has been removed from the UUNEL TRIGA teactor control room, Momioring previously processed and displayed by the Series /l has been moved to the control console. Two new digital temperature controllers were installed in the console in May 1992. Each controller is coupled to a separate instrumented fuel element located at different positions in the reactor core. The controllers form two independent and redundant fuel element temperature measuring and . ,

safety channels.

3. Surveillance Tests. i (Documentation of all sutveillance activities is retained and stored by the facility.) ,

. a. Control Rod Worths. i

, i Carefpnficuration #22 3 Julv 1991 Kluh.lRJ){ 9 July 19.21 -l Safety Rod $2.17 $2.13 $2.20 Shim-safety Rod $1.S5 $1.56 $1.49 Regulating Rod $0.25 $0.25 $0.24  ;

c Excess Reactivity $0.75 $0.71 $0.60 l Shutdown Margm $ 1.08 $ 1.10 $1.13 i Gre Confin4 ration #22 23, July 1921- 25 July 1091 26 July 1991 j

' Safety Rod $2.27 $2.06 $2.I6 Shim safety Rod $1A9 $ 1.48 $1.50 Regulating Rod $0.24 - $0.24 $0.24 l- Excess Reactivity 50.58 $0.50 $0.49

Shutdown Margm $1.15 $1.22 $1.25 l o

l l.

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j . University of Utah TRIGA Ractor 199192 Annual Operating Repon page 2 Core Con 0guration #22 2 January 1001 2J Janunty 1991 Safety Rod $2.21 $2.20 Shim safety Rod $1.34 $1.37 Regulating Rod $0.23 $0.24 Excess Reactivity $0.28 $0.29 Shutdown Margin $1.29 $1.32

b. Control Rod inspection.

The liiennial Control Rod Inspection was performed during December 1991. The control rods were sequentially removed from the reactor core for visual inspection.

Each control rod was found to be in good condition with no noticeable deterioration or corrosion having occurred since the last inspection. Rod drop times were measured on 1/2/92 and 1/21/92. All rod drop tirnes were less than 0 8 seconds.

c. Reactor Fower LevelInstrumentation.

Calorimetric power calibratic is were perforrned on 7/2/91, 4/9/92, 5/23/92, and 6/4/92. The following restilts were obtained.

Jhte_ Meter Reading , Calculated Power Level 07/02/91 70 kW 68.0 kW 04M9/92 90 kW 99.8 kW 05/23/92 80 kW 77.9 kW 06/04/92 90 kW 89.3 kW

d. ' Fuel Inspection.  ;

The Biennial Fuel Inspection was perfonned during December 1991. Each fuel element was visually inspected while kerping it submerged for shielding. No deterioration or i escessive corrosion of incore fuel elements was observed since the previous inspection.

Pool water is sampled and analyzed periodically for evidence of fission

- product activity indicative of defective or deteriorating fuel. Analyses of pool water following full. power reactor operations )asting severJ1 hours have not shown any indication of fission product leakap.

- e. Fuel Temperature Calibration.

Fuel ternperature circuits were calibrated on 8/12/91,12/8/91,4/2/92 and f/5/92. The circuits were calibrated to less than a 5'C error over the range 20'C to 500'C.

f. Reactor Safety Committee Audits.

Radiation Safety Officer and RSC member K. J. Schlager and Alternate RSO B. L tiardy audited radiation safety and ALARA practices at the facility for the period 1 July 1991 through 30 June 1992.

K. Ji Schinger and B, L.1-lardy reviewed radiation safety and monitoring at UUNEL for this reponing period.

RSC member P. S. Sheehan audited the m'sintenance and operationai activities of the

4 , University of Utah TRIGA Reactor 199192 AnnualOperating Report page 3 facility for the period 11 May 1991 through 6 December 1991.

B. l.. liardy audited the maintenance and operational activities of the facility for the period 7 December 1991 through 30 June 1992.

No significant deviations from normal operating practices were identified by these audits.

g. Environmental Surveys.

B. L Ilardy reported to the RSC a maximum total exposure of 4016 millirem per quarter to enviranmental dosimeters located at various positions surrounding UUNEl, for the period 1 July 1991 through 30 June 1992. The average quanerly exposure for the six environmental monitoring stations was 32113 millirem.

H. ENERGY OUTPUT.

The teactor was critical for 150.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> and produced 0.316 megawatt-days (7590.1 kilowatt hours) of energy during this reporting penod. Since initial criticality, the reactor has been operated for a total of 2,227.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> with an accumulated total energy output of 5.44 megawatt days (130452.6 kilowatt-hours).

C. EMERGENCY SHUTDOWNS AND INADVERTENT SCRAMS.

There were two emergency (manually induced) shutdowns of the reactor during operations this reporting period. On 6 May 1992, the reactor was immediately shutdown by the reactor ,

operator when the fuel element temperature channel failed as the reactor was brought to 90%

power (90 kW). Independent and redundant fuel temperature monitors and all power monitoring channels operated nonnally and showed no indication of reactor operation outside of technical specification limitations. The cause of the malfunction was identified after the reactor was secured. Corrective maintenance was perfonned on the channel and normal operations resumed the following day. On 27 May 1992, the reactor was intentionally shutdown when the strip chart recorder stopped recording traces of the continuous air monitor imd the log and linear power chann:Is. The recording function was momentarily lost when the operator attempted to unfreeze the alphanumeric plotting 3en by pressing its display function key; the reactor was shutdown as a safety precaution unti recording resumed. Both of these events were reviewed by the Reactor Supe s isor and since neither incident affected the health or safety of facility personnel or the genend puNic they were not considered funher.

Sixteen inadvertent (instremental) scrams occurred while the reactor was critical during this repolting period. The type, cause and action taken by the operations staff for each scram are ,

summarited below:

> Quststy Type ,., Qtuse Action ,_

5 Linear Power Signal spike while switching Restan.

t Channel power level, 1 Linear Power Sample insenion. Restart.

Channel

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l .

q , University of Utah TRIGA Reactor 199192 Annual Operzting Report

' page 4 Ouantity Tvoc Cause _ Action 4 Linear Power Scram setpoint adjusted Restan.

Channel too low.

2 Linear Power Voltage Ductuation. Restan.

Channel 3 Pool Water Water-level sensor bumped Restart 1.evel during fuel inspection.

1 Loss of Power fluctuation. Restan.

Magnet Current D. MAJOR MAINTIINANCE. 3

%c dry tube irradiator was removed from the heavy water reflector tank on 28 December 1991 during the regularly scheduled biennial inspections. The radiation embrittled polyethylene tubing immediately adjacent to the irradiator was replaced as a routine preventive maintenance procedure.

The ventilation system underwent an extensive overhaul during February 1992. The blower, motor and a section of duct were replaced to correct excessive vibration of the blower drive shaft and the resultant noise which was adversely affecting University employees working in the vicinity of the ventilation ductwork. Irstallation of the new motor / blower unit within a vibration-isolation mounting system was successfulin substantially reducing noise associated with the operation of the ventilation system. ,

E. CllANGES, TESTS AND EXPERIMENTS PURSUANTTO 10 CIR 50.59.

d As of the end of the irporting period, the current membershin of the Reactor Safety Comr..ittee (RSC) as designated by the Licensec is as follows:

Dietrich K. Gehmlich, Reactor Administrator Gary M. Sand luist, UUNEL Director and acting Reactor Supervisor Keith J. Schlager, Radiation Safety Officer John S. Bennion James M.11yme Patrick S. Sheehan David M. Slaughter The control Instrumentation of the TRIGA Mark 111 control console, obtained from the decommissioned Berkeley Research Reactor (BRR, NRC License No. R-101) and installed in April 1991, continues to be improved as part of an ongoing instrumentation upgrade program.

Each monitoring and safety channel is being systematically replaced by equivalent and contemporary state-of the-art electronic circuits. Proposed modifications are reviewed for compliance with design and technical specificatinns requirements, quality assurance, and possible unreviewed safety questions by facility management and members of the Reactor Safety Committee. Completion of e s program will enhance the reactor centrol system as has already been evidenced by the notable improvement in the reliability an.1 stability of the upgmded linear and log power monitoring channels.

l 4

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( University of Utah TRIG A Reactor 199192 Annual Operating Report page 5 The RSC has reviewed and approved several NEL procedures which were modified to update and correct perceived deficiencies. The NEL staff continues to rev;cw and update facility documentation to assure compliance wi'h applicable regulations.

F. RADIDACT!VE EFFLUENTS.

1. Liquid Waste - Total Activity Released: Negligible.

A total volume of approximately 1030 gallons of liquid effluent was released to the sanitary scuerage system. Of this amount,1025 gallons resulted from the disposal of the shield water from the AGN 210M training reactor, NRC License No. R 25, which is currently tving decommissioned. The remaining liquid effluent consisted of mop water from routine "

housekeeping operations. Prior to release, independent analyses by the Radiological llealth Department confirmed that the effluent contained no radioactivity in excess of naturally occurring radionuclides nomially present in the potable water supply of this arer

2. Gaseous Waste Total Estimated Anivity Released: 58.7 pCi.

The TRIG A Reactor was operated for 150.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> at power !evels up to ap proximately 95 kW. At this power level argon-41 production is substantially below N PC values for unrestricted areas. The minimum detectable concentmtion of Ar-41 for the stack monitor has been found to be one-third of 10 CFR 20 appendix B limits for release to unrestiicted areas. The average annual calculated concentration of Ar-41 genera'ed during operations is estimated at 1.79 x 10-10 pCi/ml which is approximately 0.5% of the MPC for this

- radionuclide. The total amottnt of Ar-41 released was estimated at 58.7 pCl. No phosphorus-32 was released from UUNEL during this period. The total amount of all .

gaseous radioactivity released was estimated at $8.7 pCi. A monthly summary of gr.scous releases is given in table 1.

Table 1.

Summary of Monthly Gaseous Radioactive Effluent i July 1991 through 30 June 1992 Estunated Release ( uCil MDnth Atal P_:222nd.altettu:n Tntal July 12 3 0 123 August 93 0 93 September 8.6 0 8.6 October 0.0 0 0.0 Nosember 1.6 0 1.6 Dxember 5.6 0 5.6 January 4,8 0 4.8 Febmary 13 0 13 Mxth 0.0 0 0.0 April 3.7 0 3.7 May 7.2 0 7.2 June 43 0 43 Total activity of gaseous effluent (pCi): 58.7 0 58.7

q , Ur,1versity of Utah TitlGA Reactor

, 199192 Annual Operating Report page 6

3. Solid Waste Total Activity: none Approximately 0.3 cubic meter of salid waste consisting of low-level decontamination materials, detwis renwved from the reactor tank during cleaning, and irradiated samples was generated by the facility during the reporting period. Other s.olid waste which has ,

accumulated from 1)ast operations, including spent ion-exchange resin from the pool-water purification system, is being stored in the Controlled Access Area of the facility pending characterintion and subsequen: transfer to the Radiological llealth Department for -

disposal.

G. RADIATION EXPOSUltES.

Personnel with duties in the reactor laloratory on either a regular or occasional basis have been issued a fihu badge %simeter by the University of Utah Radiological llealth Department. The duty category and n . .titoring period of personnel are summarized below:

Name .

Monitoring PcIhyJ_ lluty Categu Gary Sandquist 7/1/91-680S2 regular John Hennion 7/1/91-6S 0/92 regular David Slaughter 7/1/91-6 SON 2 reguhtr Todd Gansauge 7/1/91-600/92 occasional Kevan Crawford 7/1/91-6S 0/92 occasional Byron liardy 7/1/91-6SO/92 occasional Cynthia llenderson 7/1/91-6S 0/92 occasional Sharon Packer 7/1/91-680/92 occasional Medhi Tahen 7/1/91-6 S 0/92 occasional lirad Varca 7/1/91-6SO/92 occasional Ilenry Moeller 7/1/91-6 S 0/92 occasional Vinh Tang 1/1/92-6S 0/92 occasional Cluisty Seiger 1/lN2 6SO/92 occasional Ross Schmidtlein 1/1/92-6SO/92 occasional Rian Smith 1/1/92-6/30/92 occasional John Moore 4/1/92-6/30/92 occasional Rotv.rt llenderson 4/1/92-6S 0/92 occasional James Godfrey 4/IS2-6SO/92 occasional Enrique Estrada 4/1/92 6SO/92 occasional Quyen Tang 7/1/91-3D1/92 tem'inated Dose Equivalent summary for Reporting Period:  !

Menured Doses 7/lSi - 6 SON 2 Doses: <10 mrem average; 29 mrem highest measured.

Dese Equb.21ent Lu ats Maximum Permissible Dose Equivalent = 5000 mrem /yec (1250/ quarter).

Minimum Detecable Dose per Monthly Badge = 10 mrem. ,

4 '

University of Utan TRIGA Reactor 1991-92 Annual Operating Report

_ page 7 Of the 375 visitors to the facility under the DOE Reactor Sharing Program for the reportirg yrv, no visitor received a measurable dose. Therefore, the average and maximum doses arc all within NRC guidelines. A summary of whole body exposures is presented in Table 11.

Table 11.

Surnmary of Whole lhly Expnutes 1 July IW1 through 30 lunc 1992 Estimated whole lody exposure Numtv:r of individuals in range (rem): cach range:

No Measurable Ixtse 17 less than 0.10 4 0.10 to 0.25 0 0.25 to 0.50 0 0.50 to 0.75 0 0.75 to 1.00 0 1.00 to 2 00 0 2.00 to 3.00 0 3.00 to 4.00 0 4.00 to 5.00 0

% Greater than 5 rem 0 Total number of individuals trpvted: 21 H. LABORATORY SURVEYS.

Monthly surveys of the facility were conducted by the University of Utah Radiological Health Department during the reporting period. Some of these surveys have identified minor localized removable contamination sources which were immediately cleaned. The surveys have not indicated any unusual rad:ation levels over previous years. Records of surveys are retained by th?. facility.

1. ENVIRONMENTAL SURVEYS.

The Air Monitoring Station, operated by the U.S. Environmental Protection Agency and located outside the reactor building, has indicated no unusual changes in radiation or radioactive material concentrations during the. reporting period.

Environmental n onitoring conducted by the University of Utah Radiological Health 9

Department indicated no unusual dose rates in the areas surrounding the Merrill Engineering Butiding, which houses the reactor facility.

<, c Prepared by: John S. B m. Sr. R ghe,.V Date: 25 August 1992 S,

/,/ f,/birector..UUNht '

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