ML20236P078
| ML20236P078 | |
| Person / Time | |
|---|---|
| Site: | University of Iowa |
| Issue date: | 06/30/1998 |
| From: | Wendt S IOWA STATE UNIV., AMES, IA |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9807160145 | |
| Download: ML20236P078 (5) | |
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IOWA STATE UNIVERSITY oc;'a'" . " '"$"i S"*ic . gi ee,ieg Eo i OF SCIENCE AN D TECH NOLOGY 2o25 11. M. Black Engineering Building
. Ames, Iowa 50011 226o 535 294-1423 FAX 515 294 326:
Docket No. 50-116 Ref: 10 CFR 50.71 (a)
July 9,1998 U.S. Nuclear Regulatory Commission ATrN: Document Control Desk Waslungton, DC 20555 To Whom it May Concern:
Please find enclosed the Annual Operatens Report for the Iowa State University UTR-10 reactor. The period covered by this report is from July 1,1997 to June 30,1998.
- Sincerely, Scott E. Wendt, Reactor Manager Mechanical Engineering Department Enclosure
_ c: American Nuclear Insurers l l D.B. Bullen, Facility Director j l A.F. Rohach, Reactor Use Committee l E.E. Sobottka, Dir., Environmental Health & Safety I l
R.A. Jacobson, Chm., Radiation Safety Committee SO W.R. DeVries, Clun., Mechanical Engineering Department O U.S. NRC, Region III d-
_ ci v 3
. Annual Operations Report Iowa State University's UTR-10 Reactor Docket No. 50-116 July 1,1997 to June 30,1998 This is a routine operations report to the Nuclear Regulatory Commission in accordance with the requirements of Section 6.6 of the Technical Specifications, Appendix A to Operating License R-59.
- 1. Summary of reactor operating experience including the enemy produced by the reactor:
' The reactor is operated in support of the teaching and research efforts of the university faculty. During this reporting period, both a laboratory experiment and a research project for the Physics department were conducted. The purpose of the laboratory experiment was to demonstrate radioactive decay using activated silver dimes and copper pennies.
The purpose of the research project was to characterize the effect of neutron irradiation on fiber optics. The reactor was also used to support the training of reactor operations personnel The final reactor criticality was May 8,1998. Reactor operations were officially ceased on May 15,1998.
. During the period July 1,1997, to June 30,1998, a total of 44.9 kW-hr of energy production and 73.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> of operation were recorded. Last year's numbers were 56.7 kW-hr and 126.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> ofoperation. Since the initial criticality of the LEU core in August of 1991, the cumulative kilowatt-hours are 305.0 kW-hr and the cumulative hours i of operation are 869.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. The total energy produced during the life of the facility !
(both HEU and LEU cores) is 7629.1 kW-hr with a cumulative operation time of 9540.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />. A percentage breakdown by operational categories for the years 97-98 and 96-97 is shown below.
Table 1. Allocation of energy production and operation time,in percent.
Year Research Teaching Teaching Maintenance Operator Senice Undergrad. Graduate Training Energy %
97-98 61.9 0.1 0.0 35.7 2.3 0.0
% 97 0.0 49.8 0.0 47.5 2.7 0.0 Time %
97 98 39.9 12.5 0.0 15.4 32.1 0.0 :
%-97 0.0 38.6 0.0 30.0 31.4 0.0 i
Annual Operations Report for R-59.. . Page 1 of 4 j
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- 2. Unscheduled shutdowns including, where applicable, corrective action taken to preclude recurrence:
During this reporting period, there were two unscheduled shutdowns. One shutdown occurred while filling the core tanks, but prior to reaching ' normal operating level' (NOL);
[ the other occurred aAer reaching NOL, but prior to the withdrawal of any of the control j rods.
l The first unscheduled shutdown occurred on 7/31/97. A reactor start up was underway in l order to perform a calibration of the nucle ~ar instrumentation. Prior to reaching the normal
! operating level (NOL), and prior to pulling control rods, a Rate I scram (reactor period <
5 seconds) was received. Upon investigation it was determined that the scram was caused
! by a voltage fluctuation which occurred as a result of the operation of the bridge crane.
This was confirmed and reactor restart was approved aAer the bridge crane was secured.
l All reactor operations staff were informed of this and instructed to secure the crane prior i
to all reactor operations.
The second unscheduled shutdown occurred on 9/19/97. A reactor start up was underway
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in order to provide operator proficiency training. AAer reaching NOL, but prior to pulling control rods, a low flow alarm was received. The reactor operator observed that the indicated flow rate was 0.1 gpm. Suspecting that the problem was in the Process l
- Instrumentation Calibrate / rest switch, the reactor operator cycled the switch. In doing j l so, a High Moderator Level scram was received due to the process instrumentation test switch not being fully in the operate position. ARer cycling the switch, the flow meter indication returned to a value within the accepted range and reactor restart was approved.
l The electrical contacts on the process instrumentation switch were cleaned again and the reactor operations staff was reminded to check position of the switch prior to closing the
- dump valve.
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- 3. Major preventive and corrective maintenance operations having safety significance:
i ARer an extended outage last period, the reactor was cleared for normal operations on August 1,1997 and remained operational until May 15,1998 when operations officially ceased. During that time, all surveillance and maintenance activities required by Technical Specifications were completed within the specified time intervals.
Throughout the reporting period, monitoring of the "in core" cladding samples continued.
The samples do not appear to be changing. Also, fission product analysis using the high purity germanium detector (HPGe) continued. No fission products have been detected in the primary coolant.
Annual Operations Report for R-59.. Page 2 of 4 i l
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- 4. Major changes in the reactor facility, procedures, and new tests or experiments, orboth, that are significantly different from those performed previously and are not described in the Safety Analysis Report, including conclusions that no un-reviewed safety questions were involved:
A proposed experiment to take x-ray images of some of the spare fuel plates was reviewed and approved by the Reactor Use Committee. The number offuel plates to be x-rayed at any one time was limited to the number in an intact fuel assembly. The committee concluded that no un-reviewed safety questions existed.
A new procedure for the in-transit protection of special nuclear material of moderate l strategic significance was reviewed and approved. The procedure was required in order to I ship the HEU fuel to the DOE's Savannah River Site.
Three new reactor experiments for the irradiation of fiber optic cables and other related electronic components were approved by the Reactor Use Committee. The first l experiment used an existing holder to position gold foils between two fuel plates in a fuel l
assembly. The activated foils were then used to determine the neutron flux in that region I
of the core. N second experiment placed optical fibers in the same region of the core as the gold foils. The fibers extended through the biological shielding so that their ability to transmit signals could be monitored during irradiation. For the third experiment, a variety l of electronic components were irradiated in the rabbit tube. The components were removed after receiving larger and larger neutron doses to determine the extent to which they were damaged. The committee determined that there were no un-reviewed safety questions with the three experiments.
After reactor operations ceased, modifications to the coolant system piping were required
' in order to comply with NRC guidelines for releasing the primary coolant to the sanitary sewer system. First, the DI column was removed to allow for an increased flow rate through the existing filter. Second, several additions were made to the in-line pump-out leg. The direct line from the pump to the dilution tank was replaced with a ' filter leg'.
Two filters were added downstream of the pump followed by a 300 gallon holding tank.
The holding tank retains the water until it can be analyzed, after which a valve is opened allowing the water to drain to the building dilution tank and ultimately the sanitary sewer.
These changes were discussed with, and approved by, the Reactor Use Committee prior to implementation. The committee determined that no un-reviewed safety questions were involved.
There were no major changes in facility tests.
Annual Operations Repon for R.59... Page 3 of 4
- 5. Summary of the nature and amount of radioactive emuents released or discharggl to the environs beyond the effective control of the University as determined at or before the point of such release or discharge. (Estimates of
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individual radio-nuclides present in the emment are included, to the extent !
practical):
Argon-41: The operating records show that less than 0.0016% of the concentration allowed by 10 CFR 20, Appendix B, Table II were released to the environs. This estimate is based on 44.9 kW-hr of energy production.
Others: On June 23, the water comprising the primary coolant (220 gallons) was released to the sanitary sewer system. The water was processed using a series of filters to remove insolubles. Per NRC information notice 94-07, the final filter was a 0.45 micron membrane filter. Before release, it was determined that the water contained a max.imum of 0.87 pCi of Cs-137 and 17.7 pCi of H-3.
The release of the approximately 2400 gallons of water in the reactor's experimental
" shield tank" is expected to occur early in the next reporting period.
- 6. Summarized results of any environmental surveys performed outside the facility:
No environmental surveys outside the facility were required since the trigger level, based on surveys inside the facility, was not exceeded.
- 7. Summary of exposure received by facility personnel and visitors:
l No facility personnel or visitors had exposures greater than 25% of that allowed or
! recommended The only recorded exposure during the reporting period was 50 mrem to
! the finger badge ofone SRO.
t
- 8. Summary ofitems or events of significance which are NOT required to be l reported to the NRC by Technical Specifwations:
The bulk ofISU's HEU fuel was returr.ed to the DOE during this reporting period. This fuel had remained in storage at the facility after the HEU to LEU conversion process was completed in 1991. The fuel was shipped to the Savannah River Site using the BMI-l shipping cask. The two shipments occurred on March 18 and March 30.
The process to select a contractor to decommission the UTR-10 began in April.
Proposals were received from eight contractors, and it appears that Duke Engineering &
Services will be selected as the primary contractor. It is expected that the fuel pit will be characterized in late July, the core off-loaded in early August, and the entire facility characterized in late August. The submittal of the Decommissioning Plan should occur in late 1998.
Annual Operations Report for R 59.... Page 4 of 4
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