ML20006F156

Ro:On 900126,discovered That Reactor Room Sealing Dampers Did Not Fully Seal When in Closed Position During Insp of Ventilation Sys.Dampers Repaired & Returned to Svc on 900126

ML20006F156
Person / Time
Site:	Armed Forces Radiobiology Research Institute
Issue date:	02/07/1990
From:	Irving G, Maria Moore DEFENSE, DEPT. OF, DEFENSE NUCLEAR AGENCY
To:	Kaufman P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 9002270218
Download: ML20006F156 (7)

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DEFENSE NUCLEAR AGENCY ARMED FORCES RADIOBIOLOGY RESEARCH INSTITUTE

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SUBJECT:

Licensee Event Report February 7,1990 l

United States Nuclear Regulatory Commission Region I

• Division of Reactor Projects, Projects Branch No. 2 Attention: Mr. Paul Kaufman 4

. 475 Allendale Road King of Prussia, Pennsylvania 19406 i

Dear Sir:

Please find enclosed the Licensee Event Report prepared in accordance with 10 i CFR 50.73 as per telephone communications and facsimile transmission of January ,

30, 1990.

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/GEORG . IRVING, III -

Colonel ' AF,BSC i Direct

Enclosure:

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. 1 Licensee Event Report 3

for the ,

AFRR1 TRIGA Reactor Facility Prepared by:

1st Lt Matt Forsbacka hit. Tom Wright Mr. Mark hfoore c h Reactor Facility Director l

Approv d for Release:

' George . Ihving,dIl f Colone . SAF, BSC Direct r AFRRI

' Abstract On 20 JAN 90, 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 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 time 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, 1 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

\/ system has shown no release of fission products nor has periodic testing of the reactor pool water shown any release of radioactive contaminants in the reactor room.- The reactor room scaling dampers were repaired on 20 JAN 00 and were returned to service that same day.

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Narrative Description of Event I DEkKInnd. Air from the AFRRI building ventilation system is supplied to the AFRRI TRIGA Reactor Facility through a single supply damper. As shown in i Figure 1, the supply air is delivered to the exposure facilities, reactor control room i

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 itnd D-30 in Figure 1).

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Technical Specifications for the AFRRI Reactor Facility require the ventilation system to the reactor 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 Description. 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 scaling dampers on January 20, 1990. The inspection was performed with a vane anemomuer 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 an indication of some air movement through the ducts. No power operations were in 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.

Chronolorv of Events. The following is an approximate chronology of events regarding the discovery and correction of the reactor room sealing damper leakage:

20 JAN 90 0000 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: all 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 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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. 1500 All repairs are complete. System is retested by SFC Reed and the contract technician Dampers are found to be fully operable at this time.

1530 MAJ Felty, Reactor Operations Supervisor, attempts to call hir.

Paul Kaufman, USNRC project engineer, at Region I. Mr. Kaufman

is unavailable at this time.

29 JAN 90 0900 MAJ Felty attempts to call Mr. Kaufman, but is again unsuccessful.

30 JAN 90 0900 MAJ Felty contacts Mr. Kaufman and apprises him of the now corrected situation.

Method of Discoverv. As has been previously mentioned, the positive scaling dampers were found to be leaking air during a routine inspection of the ventilation systern. The in trument used during the inspection was a vane anemometer.

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 restricted Dow through a closed or partially closed air damper. Thus the volumetric leakage rate through the closed dampers could not be determined.

Automatically Initiated Safety System Restionse. Air that passes through the reactor room is passed through a bank of high efGeiency Glters as is shown in Figure 1. The absolute filters shown insure the stoppage of particulate material 0.3 Inicrons or larger with an efficiency of 09.07% This filtration system, which is engaged at all times, protects the general public frotn any release of airborne l particulate contaminants. The Oltration system was dioetyphthalate penetration tested on November 4,19S8 (the date of new filter installation) and was determined to be fully operable with no change of filter to this date.

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C Assessment of the Safety Consequences The high efficiency air filtration system previously mentioned serves as - % ekup system to' protect the public in the event of a damper failure during a W.ase of 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 radioactive contaminants are completely being contained by the alt filtration system. In the highly unlikely event that contaminants pass through the air filtration system, the reactor staff could completely isolate the reactor facility by  ;

closing the isolation dampers or activating a shutdown of the main supply and exhaust fans shown in Figure 1 as a tertiary protective measure.

i Description of Corrective Actions  ;

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 sinnilar . events 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)-205-1200.

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