ML20006G226
| ML20006G226 | |
| Person / Time | |
|---|---|
| Site: | Armed Forces Radiobiology Research Institute |
| Issue date: | 02/22/1990 |
| From: | Irving G, Maria Moore ARMED FORCES RADIOBIOLOGICAL RESEARCH INSTITUTE |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20006F188 | List: |
| References | |
| NUDOCS 9003060207 | |
| Download: ML20006G226 (5) | |
Text
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J Licensee Event Report for the AFRR.I TRIGA Reactor Facility Prepared by:
1
', Matt Forsbacka h.t. Tom Wright
,c Mr. Mark Moore h
-l o.t Reactor Facility Director
.a Approv d for Release:
George.
. Irving,dII Colone SAF, BSC Direct AFRRI Abstract
- On.26 JAN 90, the AFRRI TRIGA ventilation system was inspected by 'a contractor and a reactor ~ staff member to ensure the full isolation capabilities of l
'the reactor room sealing dampers as specified by contract and SAR. During this-inspection it was found that _the dampers did-not fully seal when in the closed position._ No power operations were in progress' at the dme of the discovery, and no power operations were permitted until the-dampers:were adjusted to-specifications._ It is unknown how long the dampers have been in' this condition, however,'it can be stated with certainty that the public was fully protected as the dampers: are backed up by a bank of high efficiency filters prior to exhausting reactor room' air to the atmosphere. In addition, the continuous air monitoring
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system has shown no release of fission products nor has periodic testing of the
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reactor pool wai.er shown any release of radioactive contaminants in the reactor room.' The reactor room sealing dampers were repaired on 26 JAN 90 and were returned to service that same day.
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. Narrative Description of Event Bacharound. Air from the AFRRI building ventilation system is supplied to the AFRRI TRIGA' Reactor Facility through a single supply damper. As shown in Figure 1, the' supply air is delivered to the exposure facilities, reactor control room i
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. and offices,- and the reactor room. To provide isolation capabilities of the reactor -
room, and thus mitigate the consequences of potential airborne contamination, the reactor room air supply and exhaust ducts are provided with positive sealing dampers (D 29 and D-30 in Figure 1).
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Figure 1. Diagram of Ventilation System Page 2
I Technical Specifications for the AFRRI Reactor Facility require the ventilation system to the re' actor room to be secured via closure dampers which are activated by a signal from the reactor deck continuous air monitor. The Safety Analysis Report specifies that the dampers, when in the closed position,-will restrict air movement in or out of the reactor room via the ventilation system.
Event Descriotion. The AFRRI TRIGA ventilation system was inspected by a contractor and a reactor staff member to ensure the full isolation capabilities of the reactor room sealing dampers on January 26, 1990. The inspection was performed with a vane anemometer placed at the inlet and outlet of the exhaust and supply air ducts respectively. While the dampers were in the closed position, the vanes of the anemometer were observed to be rotating -- this was ar.
, indication of some air movement through the ducts. No power operat ons were in i
progress at the time of the discovery, nor were any power operations permitted until the dampers were adjusted to specifications. Although it is not known how long this condition has been in existence, continuous air monitoring shows with complete certainty that there has been no release of fission products or any other airborne radioactive contaminants from the reactor room to the atmosphere.
- Chronology of Events. The following is an approximate chronology of events regarding the discovery and correction of the reactor room sealing damper leakage:
26 JAN 90 0900 Air dampers are found to be leaking air in the closed position
. during routine testing by SFC ' Wayne Reed, an AFRRI SRO, and a ventilation technician from Comfort Air. The problem is reported to the RFD immediately; ali power operations for that day are cancelled.
1000 investigation shows that the rod connecting the damper section of the reactor room exhaust duct is hitting the bottom of the duct
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and preventing the ducts from completely closing. Repairs are initiated at this time.
1200 Investigation shows that the gasket material on the reactor room supply duct is worn. New gasket material is applied at this time.
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i s,.I $ ~. ' 4 7
s 1500
. All repairs are complete. Systern is retested by SFC Reed and the
- contrs.ct technician. Dampers are found to be fully operable at this 1
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time.
I 1530 MAJ Felty,- Reactor Operations' Supervisor, attempts to call Mr.
Paul Kaufman, USNRC project engineer, at Region I.~ Mr. Kaufman is unavailable at this time.
1 29 JAN 90 0900 MAJ Felty attempts to call Mr. Kaufman, but is again unsuccessful.
3 30 JAN 90 a
~0900 MAJ Felty contacts Mr. Kaufman and apprises him of the now corrected' situation, j
Method of Discovery.~ As has been previously mentioned, the positive sealing dampers were found to be leaking air during a routine inspection of the ventilation system. The instrument used during the, inspection was a vane anemometer.
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- Although the vane anemometer is a good instrument to determine volumetric flow rates through an open duct or pipe, it is only useful as a leak detector for highly
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restricted flow through a closed or partially closed air damper. Thus-the volumetric
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leakage rate _through the closed dampers could not be determined.
Automatically Initiated Safety System Resoonse. Air that passes through the -
reactor room:is-passed through a bank of high efficiency filters as is shown in
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Figure 1.: The absolute filters shown insure the stoppage of particulate material 0.3 microns or larger with an efficiency 'of 99.97%. This filtration system, which is engaged at all times, protects the general public from any release of airborne particulate contaminants. The filtration system was dioctyphthalate penetration i
tested on November 4,1988 (the date of new filter installation) and was determined to be. fully orcable with no change of filter to this date.
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Assessment of the Safety Consequences The high efficiency air filtration system previously mentioned serves as a backup system to protect the public in the event of a damper failure during a release of l-airborne particulate contaminants. Since the. air is continuously monitored in the reactor room as well as in the reactor exhaust stack, it can be easily determined if 1
l radioactive contaminants are completely being contained by the air filtration l_
system.- In the highly unlikely event that contaminants pass through the air filtration system, the reactor staff could completely isolate the reactor facility by L
closing the isolation dampers or activating a shutdown of the main supply and exhaust fans shown in Figure 1 as a tertiary protective measure.
Description of Corrective Actions L
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The AFRRI TRIGA staff has increased the surveillance of the reactor. room isolation dampers by including a semi annual leak test which will be done in addition to the monthly visual checks of damper operability. This leak testing will be accomplished by-using a vane anemometer to detect air motion near the -
damper inlet and exhaust.
Reference to any previous similar events-E None.
Point of Contact for any Questions Points of Contact for further information are the Reactor Facility Director, Mr.
Mark Moore and/or the Reactor Operations Supervisor, MAJ James Felty, telephone (301)-295-1290.
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