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Annual Rept 1981.
	ML20040F576
Person / Time
Site:	U.S. Geological Survey
Issue date:	12/31/1981
From:	; INTERIOR, DEPT. OF, GEOLOGICAL SURVEY
To:	;
References
	NUDOCS 8202090365
	Download: ML20040F576 (9)
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U. S. Geological Survey TRIGA Reactor ,^l

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S ANNUAL REPORT g G' gr January 1, 1981 - December 31, 1981 g

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@ a NRC License No. R-113 -

Docket No. 50-274

1. Administrative Changes ,

There have been no administrative changes during -his period.

II. Operating Experience -

The prime function of the Geological Survey TRIGA Reactor (GSTR) for the year 1981 continued to be the provision of neutrons for the various research programs being conducted by cit e U.S.

Geological Survey. Irradiations were also p e r f o rta ed for other .

Governmental agencies and educational institutionc.

A listing of all irradiations performed during the year 1981 is listed below.

Organization Satples (1981)

Geologic Division (Denver) 22,695 Oregon State University 42 Geologic Division (Menlo Park) 28 University of Georgia 21 /,

Geologic Division (Reston) 15 University of Utah 3

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8202090365 811231 DR ADOCK 05000274 PDR

' 2 The specifics of operations relating to performance character-istics, changes in the facility design, or operating procedures are:

A. Thermal power calibrations at 50 KW were performed in January and June, 1981.

B. Three standard and one thermocouple TRIGA fuel elements were added to the core in January 1981.

C. The control rods were inspected and calibrated in January 1981.

D. No Class II experiments were approved during this period.

E. During the report period, 189 daily checklists and 12 monthly checklists were completed in compliance with Technical Specification requirements for surveillance of the reactor facility.

F. Tours of the reactor facility were provided to 18 groups during the year. The major groups visiting the facility were affiliated with:

Rockwell International Bendix Corporation Southern Methodist University University of Wyoming Highland High School University of Utah Colorado School of Mines Marathon Oil Company Colorado State University Green Mountain High School During the year, 242 visitors were admitted to the reactor facility.

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3 III. Tabulation of Energy Generated Megawatt Time Reactor Pulsing Month Hours Was Critical Number - K/B January 1981 58.815 83 hours9.606481e-4 days 0.0231 hours 1.372354e-4 weeks 3.15815e-5 months 31 minutes 0 Feburary 1981 59.117 68 hours7.87037e-4 days 0.0189 hours 1.124339e-4 weeks 2.5874e-5 months 28 minutes O March 1981 51.052 58 hours6.712963e-4 days 0.0161 hours 9.589947e-5 weeks 2.2069e-5 months 18 minutes O April 1981 118.896 132 hours 46 minutes O May 1981 77.098 84 hours9.722222e-4 days 0.0233 hours 1.388889e-4 weeks 3.1962e-5 months 14 minutes 0 June 1981 66.223 76 hours8.796296e-4 days 0.0211 hours 1.256614e-4 weeks 2.8918e-5 months 53 minutes 0 July 1981 64.761 77 hours 24 minutes 0 August 1981 79.528 87 hours0.00101 days 0.0242 hours 1.438492e-4 weeks 3.31035e-5 months 45 minutes O September 1981 64.179 69 hours7.986111e-4 days 0.0192 hours 1.140873e-4 weeks 2.62545e-5 months 49 minutes 0 October 1981 54.600 71 hours8.217593e-4 days 0.0197 hours 1.173942e-4 weeks 2.70155e-5 months 34 minutes 0 November 1981 76.699 86 hours9.953704e-4 days 0.0239 hours 1.421958e-4 weeks 3.2723e-5 months 00 minutes 0 December 1981 72.967 81 hours9.375e-4 days 0.0225 hours 1.339286e-4 weeks 3.08205e-5 months 39 minutes O_

Total 843.930 978 hours0.0113 days 0.272 hours 0.00162 weeks 3.72129e-4 months 21 minutes 0 IV. Unscheduled Shutdowns Emergency Shutdowns - number and reason

1. Automatic Scram - Physical shock to console. Serial #268

2. Automatic Scram - Transient during range Serial #278 change.

Unscheduled Shutdowns - number and reason

1. Manual Scram - Pneumatic system. " Sample stuck Serial #269 in transit out" signal. Broken capsule - all pieces returned.

2. Manual Scram - Pneumatic system - CTD Serial #270 (Controller-Timer-Display) stopped running.

3. Manual Scram - Pneumatic system - "A" sample Serial #271 changer stuck.

4. Manual Scram - Pneumatic system - CTD stopped Serial #272 running.

5. Manual Scram - Pneumatic system - CTD stopped Serial #273 running.

6. Manual Scram - Pneumatic system - CTD stopped Serial #274 running.

7. Manual Scram - Pneumatic system -

" Sample stuck Serial #275 in transit out" signal. Photo-cell failure.

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8. Manual Scram - Pneumatic system - CTD stopped Serial #276 running.

9. Manual Scram -

Pneumatic system - CTD lost Serial #277 program.

10. Manual Scram - Lost magnet current to Reg. rod. Serial #279

11. Manual Scram - Lost magnet current to Reg. rod. Serial #280

12. Manual Scram -

Pneumatic system - " Sample stuck Serial #281 in transit out" signal. Photo-cell failure.

13. Manual Scram -

Pneumatic system - CTD lost Serial #282 program.

14. Manual Scram - Pneumatic system - " Sample stuck Serial #283 in transit in" signal. Capsule stuck in changer block.

V. Major Maintenance Operations A. Water Systems

1. The demineralizer resin was changed once during the year.

2. Repairs were made to make-up valve and sump pump on secondary water system.

B. Control Rods

1. The control rods were inspected and calibrated.

l VI. Summary of 10 CFR 50.59 One incident was reveiwed under 10 CFR 50.59 and is described below:

During the control rod inspection on January 5, 1981, a scribe used to align the bolt pattern in the Reg. rod extension shaft was dropped into the pool. Turbulence of the water prevented the scribe from being observed when it was dropped.

The scribe was approximately 4-inches long and approximately 1/2-inches in diameter.

At the time the scribe was dropped, fuel was out of four positions in the B-ring, and two-positions in the G-ring (G-5 and G-10). Fuel was removed from the remainder of the B-ring and the

! hexagonal section in the center of the core (including the -

central thimble) was removed. A light was lowered into the l

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5 opening and an inspection was made with binoculars. The entire area was clear. Inspections through binoculars were also made of the other vacant fuel positions. Binoculars were also used to thoroughly inspect the top of the core, the tank, and with the aid of a large mirror, the area under the core. No sighting of the scribe was made. The bottom of the pool was vacuumed, but that also failed to locate the scribe.

Evaluation of the possible hazards indicate the most likely events would be interference with the movement of a fuel element, or interference with the movement of a control rod. Fuel elements are infrequently moved. The operator can feel when the element is properly seated, therefore it is not believed this presents a safety problem. The small size of the scribe would indicate that it would not interfere with more than one control rod at any given time. Since the control rods were in their positions at the time the scribe was dropped, it would not have been able to fall into the guide hole in the upper grid plate with the control rod; however, it is possible for the movement of the tank water to cause the scribe to migrate. The most serious hazard would appear to be the interference with a control rod in a manner to prevent it from returning to the core when the reactor is scrammed. With the most reactive control rod stuck out, the shutdown margin should be in excess of 57 cents ($0.57) so that the reactor could be safely shutdown.

The movements of the control rods were carefully checked, and found to be operating in a normal manner. Travel times and drop times were measured and compared to previous measurements.

There was not any indication of interference.

There was no indication of any problem with the control rods '

and all fuel elements appeared to be properly seated; therefore, the decision was made to resume operations. Surveillance of the top of the core and the tank continues on a periodic basis, the fuel element positions will be thoroughly inspected whenever an element is removed for any reason. Special attention will be given to the checks of control rod action during the daily and ,

monthly checks. I It was concluded that the maximum credible accilent if the scribe is in the core would not result in a violation of the Technical Specifications nor would the control rod stuck out con-dition consititute an unreviewed safety question.

1 The written evaluation by the reactor staff was reviewed by I the Reactor Operations Committee and it was concluded that continued operation of the reactor did not involve an unreviewed safety question. A copy of the Committee's determination is attached.

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6 VII. Radioactive Releases A. Listed below are the total amounts of radioactive gaseous effluents released to the enviorns beyond the effective control of the reactor facility.

License (R-113 10 CFR 20 Argon-41 Allowable Tritium (HTO) Allowable Month (curies) (curies) (curies) (curies)

January 1981 0.65 5.8 8.1 x 10 5 0.25 February 1981 0.55 5.8 11.2 x 10 55 0.25 March 1981 0.33 5.8 0.25 11.9 x 10 5 April 1981 1.10 5.8 7.6 x 10- 0.25 May 1981 0.84 5.8 9.9 x 10 5 0.25 June 1981 0.53 5.8 7.6 x 10 5 0.25 July 1981 0.43 5.8 8.4 x 10 5 0.25 August 1981 0.54 5.8 8.3 x 10 55 0.25 September 1981 0.66 5.8 0.25 October 1981 10.2 x 10_5 0.33 5.8 5.9 x 10 0.25 5

November 1981 0.43 5.8 0.25 December 1981 0.79 5.8 9.1x10]5 12.3 x 10 0.25 Total 7.15 70.8 1.10 x 10 3 3.00

% of allowable 10.1% 0.036%

(Note #1: The argon activities reported are integrated values obtained from the facility's gaseous stack monitor. Calculated values have been substituted for measured values in the few instances when the monitoring system was down for maintenance or repair).

(Note #2: The tritium concentrations are estimates based on the amount of water lost by evaporation from the reactor times the concentration of tritium as HTO).

B. There were no radioactive liquid effluents released from the reactor duing the year 1981.

C. No radioactive waste shipment was made during 1981.

VIII. Radiation Monitoring A. Our program to monitor and control radiation exposures included the four major elements below during the operating year 1981.

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1. Eighteen area monitors (17 gammas, 1 neutron) located throughcut the Nuclear Science Building. To provide a background signal, a small check source is attached to the scin_illation detector. High alarm set points range from 2 mr/hr to 50 mr/hr. High level alarms have been infrequent and are documented in appropriate Log Books.

2. One Continuous Air Monitor (CAM) sampling the air in the reactor bay. An equilibrium concentration of'3 x 10 B pCi/cc present for two minutes will result in an increase of 900 cpm above background. There are two alarm set points. A low-level alarm is set at 3,000 cpm, and the.high-level alarm is set at 10,000 cpm.

f Reactor bay air is sampled during all reactor operations. The fixed particulate air tilter is changed and counted daily on a Beckman Low Beta II counting system. The charcoal filter, fitted behind the air filter, is changed and counted weekly. In all instances, final sample calculations show less than MPC (10 CFR Part 20, Appendix B, Table II) concentrations for all isotopes in question in the reactor bay.

3. Contamination wipe surveys and radiation surveys with portable survey instruments are performed at least once each month. All portable instruments are calibrated with a certified 3-curie Cs-137 source and wipes are counted on a Beckman Low Beta II counting system.

Wipe surveys have shown the reactor area remains free of tactile contamination except for intermittent low level activity on work tabletops, the sample storage caves and floor. During 1981 the most aegivity detected on a wipe was 790 pCi beta plus gamma per 100 cm on a table top. Instrument surveys indicate no fixed areas of contamination and radiation leaking at outside wall surfaces have been less than 0.5 mr/hr at our maximum power level of 1 MW.

4. Personnel, I and gamma, beta and neutron film badges are assigned to all permanent occupants of the Nuclear Science Building. CaSO4:Dy dosimeters have been used at four outdoor environmental stations. Reactor facility visitors are issued L-49 self-reading dosimeters.

These monitoriing results are categorized below:

8 Ram - 1981' Reactor Staff G===ua Beta ~ Neutron Whole Body -

Highest 0.035 0.000 0.00 Mean 0.010 0.000 0.00 Hands Highest 0.100 0.000 0.00 Mean 0.080 0.000 0.00 Emactor Experimenters Whole Body Highest 0.015 0.000 0.00 Mean 0.005 0.000 0.00 Bands Highest 0.060 0.000 0.00 Mean 0.037 0.000 0.00 Eeactor Visitors All readin ss were less than 1.0 mrem.

Environmental Stations Rem 1981 Exhaust Stack 0.0902 West 0.0131 Southwest 0.0008 Southeast 0.0003

Personnel monitoring results are for the fourth quarter of 1980 and the first three quarters of 1981. -

IX. Environmental Monitoring Pursuant to reactor operating procedures, soil and water samples are collected every second year. Samples were not collected in 1981.

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United States Department of the Interior GEOI.OGICAL SURVEY BOX 25016 M.S DENVER FEDERAL. CENTER DENVER. COLORADO 80225 l\ kirl) ReliR ifi In the meeting of 23-24 February 1981, the Reactor Operations Committee reviewed the action of the GSTR operating staff concerning the metal scribe which was inadvertently dropped into the U.S. Geological Survey TRIGA Reactor pool on 5 January 1981 as described in the attached report.

The Reactor Operations Committee is in agreement that the operating staff did show adequate and proper concern over the incident and did undertake as thorough as was practical search for the missing scribe. The Committee also agrees with the conclusion that the most serious potential consequence of the failure to locate and remove the scribe would be an eventual interference with one of the control rods in a manner that might prevent the rod from returning to its fully inserted position following a reactor scram. By virtue of the fact that the Technical Specifications addtess such a stuck rod situation and that with such a stuck rod the reactor can and will be safely shutdown with the remaining control rods, the Reactor Operations Committee is in agreement that subsequent operation of the reactor does not constitute an unreviewed safety question as per CFR 50.59 (a)(2)(iii).

Y R. Douglas O' Dell Chairman Reactor Operations Committee l

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ML20040F576

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