ML20086N141
| ML20086N141 | |
| Person / Time | |
|---|---|
| Site: | Reed College |
| Issue date: | 12/05/1991 |
| From: | Joseph E Pollock REED COLLEGE, PORTLAND, OR |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9112190031 | |
| Download: ML20086N141 (9) | |
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December 5,1991 U.S. Nuclear Regulatory Commission Washington, D.C. 20555 ATTN: Document Control Desk RE: License R-112, Docket 50-288 This letter and the two attachments are submitted as a report on the
" Unusual Event" which occurred at the Reed College Reactor Facility on November 23,'1991. Please accept this report as meeting ine 30 day reporting requirement of 10CFR50.
Additional information which is still being generated will be submitted along with the Evaluation and Recovery Plan recoired by the Confirmatory Action Letter of November 25, 1991 from gir. John B. Martin, Regional Administrator, Region V, USNRC to Reeo College.
Based on that Confirmatory Action Letter and our understandings with the USNRC inspectors, we will not be manipulating control rods on the. reactor nor will we begin the inspection of fuel elements to identify the leaking element until our plan for the evaluation of. the cladding failure is approved by NRC. At this time, we anticipate submission of the Evaluation.and Recovery Plan on or about February 1, 1992.
Sincerely,
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J. Michael Pollock A
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ATTACllMENT 1
-REPORT ON " UNUSUAL EVENT" REED COLLEGE REACTOR FACILITY NOVEMilER 23,1991 DESCRIPTION OF REACTOR OPERATION IN PROGRESS The Reactor was being operated for a scheduled 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> irradiation for three bat:hes of samples. The largest set were geologic samples as part of a Master's thesis study of S.E.
On gon hot springs at Portland State. The second batch were sediment samples being analyzed for selenium as part of a high schoo: research project. The third batch were air filter samples collected by researchers at Oregon State with whom one of the reactor operators had worked last summer.
Due to the failure of the reactor heat exchanger last August, the reactor had been receiving -
limited use. Only operations which did not requin: heat removal had been performed, most less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in duration. The water temperature at the beginning of operation on November 23 was 23"C. It was projected, in advance, that the final pool temperature would be about 35 C. The most recent calibration of the Bulk-water alarm indicated that the alarm setting was 40 C. The maximum operation temperature allowed in the Technical
- Specifications is 120"F (48.8"C) .
Samples were loaded into the reactor late Friday and early Saturday. Shortly before 9:00
~ A.M.'the Acting Director contacted the initial reactor operator for final discussions of the .
days irradiation. The core excess was measured beginning at 9:30 and operating power :
(237.5kW) was achieved at 9:47. The Acting Director arnved at the Facility at about 10:15 and began loading samples from a previous irradiation for transfer and shipment to PSU. ,
This transfer took place at 12:23 and the Acting Director left the Facility. !
At about 13:15, the Acting Director was contacted by the Senior Reactor Operator on duty (SRO-3 below) because the Bulk Water Alarm had sounded with a tank water temperature
= of only 30"C. That temperature was verified by comparison of guages in the Primary Water System and an independent, portable probe measuring surface water temperature. It was decided that operation could continued provided that the temperature was checked i every 15 minutes with both the Primary Water System and the portable probes. The water ten 2perature recorded at 15:15 was 35.4 C.
i DESCRIPTION OF Tile UNUSUAL EVENT l
At 15:17 an alarm sounded in the Gaseous Stack Monitor (GSM and the room isolation
. cycle was tripped. The reactor was scrammed immediately. Since the alarm immediately ceased and the trace on the Gaseous Stack Monitor did not indicate unusually high readings, the operator (SRO-1) and assistant (SRO-2) set about trying to identify the cause of the alarm. At 15:29 the GSM and the Continuous Air Monitor (CAM) which measures activity in the restor bay both began to alarm and an " Unusual Event" was declared by the operators.
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g What follows in this section is an abbreviated description of actions taken subsequent to this declaration. Attachment 2 is a detailed chronology of events.
Consistent with requirements of the Facility Emergency Plan and Emergency Implementation Procedures, the two Senior Reactor Operators (SROs) began an evaluation of the event including collecting a sample of tank water and a CAh! filter for isotopic analysis. They also shut off the Reactor Primary Water System and began emergency notifications. Initial analysis indicated that the fission product Rb-88 was present on the air filter. Gamma radiation levels in the reactor bay remained at levels below 0.5 mR/hr.
Radiation levels on the CANT and the GShi and Air Particulate Stack hionitor (APhi) continued to rise.
The Acting Director (herafter refened to simply as the Dirretor) evaluated the data collected by the operators. One of the experimenters whose samples were in the reactor was contacted to test all samples for abnonnal natural radioactivity. None was found thus tentatively eliminating experiment failure as the cause of the airbome radiation levels.
Since luels in the reactor bay continued to rise, the Oregon State IIcalth Division was contacted to assist with radiation monitoring outside of the facility. The NRC was notified as was the Oregon Department of Energy (through the Oregon Accident Response System).
Subsequent water samples confirmed the presence of noble gas fission products (Kr-85m, Kr 88, and Xe-135) in the reactor tank water confirming a fuel element source for the activity. The activity on the CAhi filter was again analyzed as primarily Rb-88 (from Kr-
- 88) with increasing concentrations of naturally eccuring radon decay products. The reactor bay was left in its " isolation cycle" mode overnight to minimize any releases to the em . 'nment.
By about 1520 on 11/24, radiation levels on the stack monitors had retumed to normal levels. Activity determined on the CAhi was attributed entirely to naturally occurring radon gas and the room ventilation system was reestablished.
The " Unusual Event" was officially terminated at 15:20 on 11/24/91.
ESTihlATIONS OF RADIOACTIYlTY INVOINED The following information is based on the best estimates cmrently available. While we recognize that there are some problems with the calibration procedures as they are currently used at Reed, the results ere consistent enough to provide us with a reasonable assurance that we understand the nature of the activity. With assistance we have requested from the TRTR (Test Research and Training Reactor Directors Association) we intend to continue to evaluate these levels as they were measured on November 23, and to improve calibration procedures for subsequent operations.
Airborne Radioactivity in the Reactor llay:
Direct gamma radiation levels in the Reactor Bay resulting from airborne activity were measured as high as 0.4 mR/hr using a portable ion chamber and this reading is consistent (within a factorof 2) with levels recorded from a fixed Area Radiation hionitor. Assuming this level resulted from a unifonn distribution of noble gas fission product activity in the room air, a maximum value on the order of about 10 SpCi/ml in the room air is estimated (a lot of assumptions went into this calculation but the order of magnitude is accurate)..
Based on a CAM filter removed from the reactor bay about midnight on i 1/23, a maximum concentration of Rb-88 (and hence Kr-88) in the air is estimated at 3 x 10 5pCi/ml is obtained.
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Airborne Release from the Reactor Pacility The following releases are as calculated within the eftluent stack. No credit for any dilution, dispersion, or radioactive decay from that point to any point of occupancy is taken. All assumptions used are considered to be conservative,ie. to over estimate rather than undn estimate the release.
It is assumed that no radioactive particulates escaped. When the reactor bay is in the isolation mode, air is exhausted from the facility at a rate of 100 cfm in order to assure that the room remains at negative pressure and that no air escapes around doors and cracks. the small amount of air which is vented is filtered through IIEPA filters prior to release. The APM chart was indicated higher than normal levels which may appear to be from particulate release, however, the detector for this system is unshielded, is located in the reactor bay and these levels are completely consistent with din ct radiation by air within the room.
Gaseous Releases were estimated by integration of the chart recorder records and the most conservative calibration data from recent calibrations. Based on this level, an average concentration of 2.5 x 10+pCi/ml(averaged over the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the event)is estimated.
This concentration is consistent (within a factor of about 2) with an assiimption of release of noble gas from the room (at the concentrations described above) and dilution by a factor of 12 (the design dilution) within the room exhaust system prior to release from the stack.
Based on these data, a total n: lease of noble gas fission products of about 110 mci is estimated. This corresponds to approximately 0.25 MPC on an annual average.
To emphasize again, we believe that we have utilized conservative estimates at every step of this calculation and no credit is included for anything that happened to Ge gas after it left the stack. It thus represents an upper limit on the release. Simple dispersion calculations indicate that at least a factor of 10 redcction in these levels would have existed at any point outside of the Facility accessible to a human being.
We will be working with assistance provided by the TRTR to recalibrate and evaluate the entire monitoring system to try to pmvide even better estimates prior to resuming operations.
These data confirm that the emergency classification, as declared, was an " Unusual Event",
DESCRIPTION OF PRESENT AND FUTURE ACTIONS The Reed Reactor Facility Oversight Committees (Reactor Operations and Safety Committees) have met and reviewed prelin inary information on this event. Additional meetings are scheduled for January prior to completion of a final Evaluation and Recovery Plan, We have requested and been provided assistance throuph the TRTR organization and Oregon State University. We intend to continue to utihze this assistance throughout the coming evaluations.
Preliminary contact with General Atomic has been made. This contact will intensify as plans for Evaluation of the fuel Element Leak and for Recovery are developed during January.
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a J. , a ATTACilMENT 2 DETAILED CIIRONOLOGY OF " UNUSUAL EVENT" OF 11/23/91 The following chronology was ?mpared from notes taken during the unusual event which was declared on 11/23/91,invo~ ving the apparent release of fission products from a fuel element at the Reed College Reactor Facihty. It has been modified by the addition of events recalled by participants. Times reported with an
- were recorded at the time they occuntd (ir.cluding logbook entries) and serve as mileposts on which the other estimated times are based. Throughout this chronology," Director" refers to J. Michael Pollock, Acting Director, Reed Reactor Facility
- 15:17 GSM alanned; operator on duty (SRO-1) performed a Manual SCRAM of the reactor and removed the key,
- 15:29 CAM and GSM alanning simultaneously. CAM at 4kepm and rising sharply; GSM barely at alarm level. (levels checked by SRO-2) Um.sual Event declared; emergency procedures initiated. Operators moved operations to Facility Conference room.
- 15:35 SRO-2 called Reactor Supervisor; SRO-1 called pager in attempt to contact Director
- 15:40 CAM filter was changed by SRO-1; old filter was put in a plastic bag and counted on the gamma spectrometer.
- 15:44 CAM rising rapidly and approaching 6kepm (Checked by SRO-2).
- 15:52 APM reading 4.9kepm, but its failsafe has not yet tripped. (Nominal failsafe level 4kepm) GSM approximately 100 cpm, and alarming intermittently (Also checked by SRO-2)
- 15:53 Supervisor arrived at RRF, became emergency coordinator
- 15:55 Second attempt to contact Director again via pager and home answering machine.
- 16:00 SRO-1, SRO-2, and Reactor Supervisor have been issued dosimeters and are entering the bay minimally. SRO-2 entered bay, measuced CAM (9ke ,m and rising); GSM< at 120 cpm, While in the bay, a water sample was col ected by SRO-2 for gamma spectrometer analysis.
- 16:05 Notified security; mstructed them to suspend their walk through until further notice.
- 16:10 Contacted SRO-3 for advice; SRO-3 agmed to come to the facility.
- 16:15 Facility evacuated to Directon office emergency coordination center.
- 16:18 Peaks in CAM fiher were found to be the following:
RB.88 or Y-88 (latet confirmed as Rb-88)
Peaks in Pcol water:
-Na 24 Mn-56
- 16:21 Health Physicist notified. H.P. suggested that an experiment failure was the most likely cause of the readings.
- 16:27 Gates to back parking lot were checked and found to be closed and locked 16:45 SRO-3 arrived at Emergency Support Center 17:15 Director contacted staff in response to earlier page 17:30 Director arrived at Emergency Center
- 17:45 The follosving readmgs were obtained in the control room APM 20 kepm; stable for about 15 min GSM 300 cpm; stable for about 15 min CAM aux. readout; 3.3kepm. (This reading was previously found to be well below the readings of the CAM reading Iceated in the bay.)
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l 18:00 . Attempt to reach Provost failed, Director spoke with Acting President, briefed him on the situation and left message for Provost.
18:05 The Principal Investigator for the PSU geology project was contacted at his office at PSU,11e was asked to locate the samples (each 1 gram sample in the reactor was
- taken from a much larger sample retained at PSU) which are in the reactor and, using the PSU Geiger Counter, scan all samples for unusual natural radioactivity.
18:20 Provost returned call and was appraised of situation.
18:35 PSU Geology department reponed no unusual natural radiation levels in any samples.
- 19:00 Director contacted Health Physicist for concurrence in decision to allow entry into bay to collect CAM filter. Additional info to be collected includes RAM, RO-2,
'_ CAM recorder history, console CAM reading. Entry to be aborted if measurable gamma radiation dose rates are detected.
- 19:20 Reactor Supervisor's entry into the Reactor Bay with half-face, respiratory arotection aborted due to elevated gamma levels (0.4 mR/hr). APM and GSM evels steady at GSM 300, APM 20,000. Read CAM chart paper from exit conidor with telescope, reading level at 50 k epm.
19:25 Health Physicist requested to come to Facilit)'
- 19:40 Director contacted the Oregon State Health Division. Spoke with Ray Paris to request assistance in outdoor air monitoring and gamma particle monitoring.
- 19:50 (approximately) Martha Dibblee, OSilD, arrived and began interviewing staff about incident.- Health Physicist also anived and was informed of developments in the situation.
- 19:57 Contacted NRC; Director spoke with Tom Andmws of the USNRC headquarters in _ Washington.
- 20:20 Oregon State Health division contacted Reed; they are loading monitoring equipment into the vehicle; will call back on cellular phone on arrival at Reed.
- 20:27 (NRC call continuing) Stu Richards , the region 5 duty officer joined the NRC line in a conference call.
- 20:27 Oregon DOE returned call. David Stewart-Smith was appraised of the situation and was most concerned with media attention to the incident. He will be called if the situation worsens.
- 20:30 (NRC call continuing) Frank Wenslawski of the NRC will be joining the conference line.
- 20:38 (NRC call continuing) Jack Rowe of NRC headquarters joined the NRC conference line.
- 20:47 (NRC call continuing) Ted Michaels joined the NRC conference line.
- 20:51 Health Physicist and Reactor Supervisor prepare to enter the facility, but not the reactor bay; this was authorized by Director.
- 20:53 OSHD called Reed to say that they would anive at the facility in approximately
-10 minutes.
- 20:58 The Health Physcist and SRO-3 Prepan:d to enter the facility to recheck levels.
Since the Director was still tied up on the NRC call, the Health Physicist was designated as emergency coordinator.
- 21:04 David Stewart-Smith, ODOE, called Reed to inform the facility that the ODOE had notified 911 of the incident, (apparently an SOP) so that there is now some possibility of media calls. If such calls occur, we are to refer them to David Stewart-Smith.
- 21:08 SRO-3 and Health Physicist obtained the following information from the entrance to the facility.
CAM >50,000 cpm APM 18,000 cpm and declining
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4 GSM 250 cpm and declining RAM _
0.1 mR/hr -
- 21:10 llealth Ph Monague. ysicist can'tacted by the head of the Portland Fire bereau, George
- 21:12 Phone number of the Trojan shift supervisor obtained.
- 21:15 Oregon State llealth Division representatives set up air sampling equipment including zeolite cartridges for iodines and walked around the facility with survey meters (pR/hr) and detected no elevated levels.
- 21:20 PGE was contacted by lleath Physicist with request for assistance
- 21:21 (NRC call continuing) Junaid Razvi, General Atomic had joined the NRC call by this time.
- 21:22 Ilealth Physicist attempted to call ODOB Trojan inspector
- 21:28 NRC call finished with agreement that Reed would call them to call them back at 22:30. NRC has dispatched Trojan On-site inspector to Reed.
- 21:30 Provost was updated on the current situation.
- 21:42 - PGE, called; someone from PGE will bring appropriate respirators to the facility.lic is enected at 22:4510 23:00.
- 21:49 Ruth De m of DEM called. she was informed of the situation.
- 21:49 William llente of the Portland Fire Bureau arrived at the facility to offer assistance, lie was also informed of the situation.
22:00 SRO 2 was released for the night
- 22:10 (approx.) Reed College 11azardous Materials Manger notified of the event
- 22:31 Director contacted the NRC with update.
22:35 Oregon State Health Division reported that air samples of about 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> duration detected no measurable radiation levels in air near the stack.
- 23:10 PGE arrived with the respirators and other 1IP assistance.
12/24/91 ,
- 00:04 SRO 3 and the Reactorliealth Physicist entered the reactor bay, wearing full face respirator and contamination suits. SRO-3, changed the CAM filter and verified that the CAM was operational. The CAM was fully functional, llealth Physicist collected 2.51 pool water.
- 00.06 SRO-3 left the reactor bay and underwent decontamination. No contamination was found.
- 00:06 CAM filter counted and data stored on disk. Only detectable activities due to 88Rb and 222Rn
- 00:10 llealth Physicist left the reactor bay and underwent decontamination. No contamination was lound.
- 00:40 Water sample (100 ml) collected from tank counted on gamma spectrometer.
Activity detected due to 88Kr,85mKr,135Xc,24Na, and 56Mn. Ion exchange tesin started for the pool water sample collected.
- 00:55 The reading on the radiation monitors were as follows:
CAM 30k epm APM 9k cpm GSM ~ 150 cpm RAM 0.08 mR/hr
- 1:07 Jim Melfi from the NRC (Trojan on-site inpector) arrived.
- 1:32 PGE-1 left.
- 2:00 NRC called back to talk to Jim Melfi
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- 2:20 Oregon Emergency Management called back for status report. Director reported that all was stable and no off-site impacts. OEM off for the night.
- 2:30 Degan securing the facility for the night; notified community Safety to set Chem building alarms; ssked them not to conduct normal watch. Reactor Staff to handle watch.
- 7:00 Director returned to facility. Greg Cook USNRC called for additional infom1ation before leaving for Portland. Wanted FAX of pn:ss release. I indicated that it would be going out later this morning following my meeting with Reed Administraticr.
- 7:10 Status of monitors:
CAM 7,000 cpm (through window-still in alarm)
APM 3,200 cpm (Failsafe light has returned to the on condition)
GSM 65 cpm (Failsafe ligat flickering on and off with fluctuation in readings.
RAM (through window--0.07 mr/hr-normal)
- 7:30 Director called USNRC (301-951-0550) Initial conferees were Bob Faukenberry, Frank Wenslowski, and Stu Richards. Jim Melfi arrived at 7:40 and joined on the Reed end of the call.
- 9:17 PGE-1 called and indicated that PGE-2 was being dispatched to the Reed facility with decontamination and monitoring supolies as back-up to ours. Should arrive about 10:30
- 9:18 Tried to reach David Stewan-Smith, ODOE; left message on recorder.
- 9:25 Discussed status with Dan Gerrity; requested his help in notifying reactor oversight committees.
- 9:53 Manha Diblee, Oregon State IIcalth Division, called to offer assistance if we needed any more. She provided phone numbers for several OIX)E employees.
I1:00 Press Release issued 11:15 U.S.N.R.C inspectors arrived.
13:00 Several staff members were contacted to begin meeting with NRC inspectors.
15:00 Radiation levels on APM and GSM have returned to normal; failsafe lights have been on for seural hours. Alarm on CAM still sounding with level of 5,000 cpm constant since about i1:30 A.M. Particulate filter removed from CAM and counted on Gamma Spectrometer. Only detectable radiation levels were due to the particulate daughten of naturally occuring Radon gas.
15:20 The " Unusual Event" was terminated. Ventilation system was restaned to vent radon daughter activity. the NRC (headquarters) was notified.
16:00 Press conference held as scheduled in A.M. pn:ss release.
17:00 'De reactor 1lealth Physicist completed wipe tests of 5 surfaces in the reactor bay, all with negative resuhs. These results were left for the review of the Director.
11/25 (General events) The Directoc informed the IIcahh Physicist that odditional wipe-tests were required before the Reactor Bay could be declared contamination free. Wide area wipes were conducted, especially of floor surfaces. Several reactor staff assisted in the analysis of wipes including gamma spec. analysis. Additional water sample was analyzed.
The NRC inspection continued with inspectors interviewing involved staff members and l reviewing reactor logs and chart recorder records of the event and previous extended l
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l Irradiations. Numerous interviews both live and by phone were granted to news media.
Both SROs who entered the reactor bay during early phases of this incident received Whole-body counts initial results were called to the Director as negative.
11/26 (General Events) The Director met at 7:00 with the NRC inspectors. Final requests for information were delivered to the Director along with a discussion of preliminary findings. From. 8:00 to 10:30 data on gaseous release estimates and the mix of fission product gases based on entrained gases in reactor water were calculated and presented to the inspec'es. At 10:30, the Director held a briefing for supervisors of construction workert eniployed on near-by construction site. At 10:30, an exit review was presented with NW,' inspectors, Reed College Administrators, a*,J the Reactor Director. It was agreer; 'aat the NRC inspection would continue by phone contact through about Wednesday,12/4, to allow for the finding of additional facts in the investigation.
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