ML20012E984

Ro:On 900228,chamber Door of Primary Reactor Continous Air Monitors (CAM) Left Partially Open,Causing Filter to Be Several Centimeters Further from Detector than Normal. Backup CAM Will Be Wired Into Damper Isolation Sys

ML20012E984
Person / Time
Site:	Armed Forces Radiobiology Research Institute
Issue date:	03/29/1990
From:	Irving G, Maria Moore ARMED FORCES RADIOBIOLOGICAL RESEARCH INSTITUTE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9004090247
Download: ML20012E984 (4)

Text

., o l .

DEFENSE NUCLEAR AGENCY ARMED FORCES RAD 10 BIOLOGY RESE ARCH INSTITUTE BETHESDA, M ARYLAND P0814 6146 i

SIAJECT: Licensee Event Report 29 merch 1990 United States Nuclear Regulatory Commission Attn Document Centrol Desk Washington, D.C. 20665 Centlemen In accordance with 10 CFR 50.73, the attached Licensee Event Reports are subeltted for your consideretten. The point of contact for further information concerning these events is the Reector Facility Director, W.L. Moore, (301) -

296-1290.  !

hb$$Y ' /

& b. M -l CEOR E IRVING III Colonel,USAF,BhC Director

Enclosures:

es stated cc: USNRC - Region 1 - Project Engineer Division of Reactor Projects USNRC - Hoodquarters - Project Wene9er Nuclear Reactor Regulation f

9004o90247 900329 PDR ADOCK 0$00y,{,{0 <p

/f76

<(

s 9

.--------a . - - . - _ _ _ - - _M -

+A ww

F s i

l Licensee Event Ryert t

I for the  ;

AFRRI TRIGA Reacter Facility t

Prepared by:

Waj James R. Felty Robert Coorge r

I Wr Wark Woore i i N Sth<)90 Reactor Facilitk/ Director f

Approved for Release: ,

(._GeorgeW.Irving,III htYfb . <4

/

d' ' J Coldnel, USAF, BSC / t Director, AFRRI j Abstract On 28 february 1990 during a routine daily check of the Continuous Air Monitors (CAVs) it was discovered that the chamber door of the primary reactor .

CAM had inadvertently been left partially open during the daily startup. This  !

CAM is used to monitor reactor room air for radioactive particulate material. ,

When this CAM detects a level of radioactive particulate material on its filter greater than a preset level, the alarm will sound and positive sealing dampers in the ventilation system will close thereby isolating the Reactor Room from  :

the environment. A back up CAM in the reactor room was operating properly i during the early morning reactor operations and an analysis of the charts and r filter papers f rom both CAVs as well as pool mater samples shomed no release of f ission f ragments. Had there been a fission f ragment release, high efficiency particulate filters located in the ventilation exaust system would have backed l vp the dampers until the back up (AM alarm had prompted an operator to manually ,

close the dampers. -

Narrative Description of Event Backoround. The primary CAM is wired into the positive sealing dampers in the reactor room ventilation system such that af it alarms these dampers mill close to restrict airflom into and out of the reactor room The CAV samples particulate material from air by filtering it and and reading the counts from l decaying radioactive material that is trapped on the filter. luo CAVs are

c ] ,

'. located about twenty f eet f rom the Reactor dolly (the device v' sed to mose the l- , reactor across the pool). Both air intake hoses f rom the CAWS take their air l sample from above the reactor pool.

(. ,

! Event Description. The chamber door on the primary CAW mas inadvertently left l open. This caused the filter to be several centimeters further from the l l'

detector than normal. The primary CAM was still filtering reactor room air.  !

However, the air sample was not being taken from directly over the pool. l 1

i Chronolony of Events. For 28 February 1990 <

0535 CAM mas checked during morning startup. Chamber door ,

inadvertently left open,  :

i 0556 Startup is completed and rods are raised to measure reactor j excess reactivity.

0600 Reactor critical at 15 matts for eight minutes. ,

0614 Reactor Critical at 1 Wegamatt for tuenty two minutes.  ;

i 0755 Reactor critical at 500 Kilowatt for three minutes.  !

0826 Reactor critical at 500 Kilowatt for thirteen minutes.  ;

0840 (Approximately) Primary Reactor CAW chamber door discovered open  !

by Safety & Health Depart.mont representative. The Reactor i Operations Supervisor was immediatly notified of the situation. The  ;

CAM filter was replaced and the chamber door was closed.  :

f 0850 Reactor Facility Director mas notified. ,

0855 Filters for both CAWS mere taken to the radionnalysis lab and  ;

analysed.

0900 Pool mater sample mas taken and analysed. j I

1045 Maj . J. R. Felty notifies Vr. Paul Kaufman of the NRC Region I.

1 March 1990 l L

1545 Fact sheet f axed to NRC Region I, Mr. Paul Kaufman, f Wethod of Discovery. The open door on the CAV mas discovered during the  ;

routine daily check of the CAMS by a Safety and Health Department i representative. l Automatically Initiated Safety System Response. The primary CAV causes an air i damper system that regulates the ilow of air in*o and out of the reactor room }

to close whenever this CAM alarms. Because the door mas open, the collecting i response of the primary CAV mould probably have been delayed due to the tinie t for the fission products to travel to the filter as mell as the increased

• quantity that would have to be accumulated on the f ilter to initiate a responce of the primary CAV detector. The back up CAV mas operating properly. If a release of fission fragments had occured, the back up CAV mould have alarmed. >

r l

o This would have alerted the reactor operator of a problem and the operator would have scramed the reactor and investigated the alarm, i Assessment of Safety Consequences l The Absolute filters in the ventilation exaust system will stop 99.975 of  !

partical material greater than 0.3 microns. These highly ef ficient exaust l filters would have removed much of the contamination f rom a fission f ragment j release. The back up CAW ,ohich was operating properly, would have alarmed and alerted the operator of a problem in the reactor room. By procedure, the [

operator would have scrammed the reactor and manually closed the air dampers by  !

9 means of a smitch in the control room. Closing the dampers mould have sealed ,l the room thereby stoping the release of radioactive material from the reactor  :

room. j Description of Corrective Actions i To ensure that the dampers mill close in the event of a release of radioactive l material in the reactor room, the backup CAM will be wired into the damper j isolation system, in parallel to the primary CAM. This corrective action provides for a backup system that is fully capable of functioning exactly like the primary system in the event that the primaty system is ever rendered [

inoperable, ,

Reference to any previous similar events i

None f Point of Contact f or any Elvestions I

~

Points of contact for further information are the Reactor Facility Director, Mr. Vark Moore and/or the Reactor Operations Supervisor, Maj. James Felty.  ;

TeIephone Number: 301-295-1290  :

i I?

b3W$ ? L, } W .

Geor W.Irving,III  !'

Colonel, USAF, BSC Director r

i f

l f