ML20128D477
| ML20128D477 | |
| Person / Time | |
|---|---|
| Site: | Reed College |
| Issue date: | 03/17/1992 |
| From: | Pollock M REED, J.G. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML20126M891 | List: |
| References | |
| FOIA-92-35 NUDOCS 9212070288 | |
| Download: ML20128D477 (10) | |
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REED COLLEOE ortland, Oregon trios.stro u.cm r* cam I March 17,1992 To: John B. Martin, i NRC Regional Adminfetrator- l From: Michael Pollock, Director, Reed Reactor Facility 1 Re: Rooovery Plan CC: Phil Qualle, Reactor inspector, USNRC 1 Marvin M. Mendonca, Senior Project Manager, USNRC -1 The attached document is our plan for find tlie leaking fuel element in our reactor core and recovering from the Unusual Event of November 23,1991.
The plan is based on the instructione in the General Atomio Mechanloal Maintenance and 0)erating Manual for Reed College; on conversations with General Atomic staff; and on other experiences with leaking TRIGA fuel at other facilities, as reported in the proceedings of past TRIGA Users Conferences. It has been reviewed by our own staff, our Reactor Review Committee, and a representative of the National Association of Toot, Research, and Training Reactors (TRIR).
We look forward to working with you and your staff as you evaluate this proposal. Please direct any questions or comments to either Michael Pollock, Acting Director, or Paul Terdal, Associate Director, at (503)777 7222.
/ ,_ ' --_ v M:chael Pollock, Aging Director, Reed Reactor Facility e . .
9 9212070288 920505 -
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March 17,19g2 -
Reed Reactor Facility Recovery Plan
Introduction:
This report constitutes Reed College's plan to evaluate the fuel oladding leak at the Reed Reactor Paolilty (lleense R 112) on November 23,1991, as deoortbed in the NRC Region Ve Confirmatory Action 1.etter of November 25,1991.
Preliminary drafts of this plan have been reviewed by Dr A. G. Johnoon of TRTR and by Reed College's Reactor Review Committee. This report describes the preparations that Reed College plans to undertake arlor to beginning the search for the leaking fuel element, the process for dentifying which fuel element is leaking, and the process for resuming normal operations once the damaged fuel element has been identified and removed from the reactor core.
As has been the case with fuel element leaks at other facilitiest,2, and as la recommended in the documentation provided by the manufacturer *, it will be necessary to manipulate the reactor control rods and take the reactor criticat in order to isolate the leak. It is noted that in the Technical Specificatione for the Reed Reactor Facility, eaction E.4 states:
, 'Any fuel element which exhibits a clad break as indicated by a measurable release of fission products shall be located and removed from service before resumption of routine teactor operations.'
it is our opinion that this roc ulrement does not prohlblt operation of the reactor for the purpase of locating tle leak.
As per the NRC Region V Confirmatory Action Letter of November 25,1991, we request concurrence with this plan and with our Intentions to operate the reactor as outlined below.
Preparations:
, General
- 1 Bouchey, G. D. and Gage, 9. J., " Detection and location of 1.esking TRIGA Fuel Elements," proceedings of the TRIGA Ranctor Ownst's Seminar. Denver, CC, February
, 19 20, 1970. .
2 Bennion, J. S., Crawford, K. C., Gansauge, T. C., and Sandquist, G. M., 'Identmeation of t.eaking Fuel Elements," proceedings of the Twsthh U.S. TRIGA Users Confarance. Austin TX, March 11 14, 1990. .
. 3 "TRIGA Mark i Reactor Mechanical Maintenance and Operating Manual for Reed College," GA 8605, Gulf General Atomlo,1968, pp 95 97.
Reed Reactor Facility Restart Plan March 17,1992 Page1
A number of preparations will be made before o Mations to locate the fuel element leak beOl_n in order to address many of the conoems releed by the NRC Inspection of November 24 November 274, and by the staff.of the Reed Reactor Facility.: Many of these preparations are completed or are in prog rees.
- Additional preparations will be requlted, as per Amendment No. 8 to Foo fty.
. Ucense No R 112 Reed College Reactor Facility, whloh walved the time periodlofty requirements for oeffain Technloal Spoolfloatione Surveillanoso.4 Concema from NRC lomaantlan Manort 50 2AA/9101!
Paragraph 2.B.g: Sahrty Rod Motor Control.
"After the SCRAM, the safety control rod motor rotated in the outward direction (and) thus'did not reset as required. The safety rod d'opped into the core on the trip signal as required. No improper rod movement thus ooovrred. The lloonsee felt that the problem was in the balance oitoult."
Response
We believe that this response of the control rod motor Indicates that the rod down nloroswitch failed to trip following the SCRAM. We believe that into -
resulted from heat expansion of the Safety Control Rod " pull rod" during the operations. Durin0 the Startup Checkilot, performed prior to operating the reactor for the purpose of determining the source of the fuelleak, we will verify
. that the Safety Rod SCRAM function performs normally. lf maintenance is, <
requ' red, it will be completed before operatfor,a begin.
Paragraph 2.C.a: Radiation Monitors The inspectors advised that the calibrations for the Gaseous Stack Monitor (GSM) Air Paniculate Monitor (APM), and Continuous Air Monitor CAM) wers
, out of date. The Inspectors noted that the most recent efficiency ca(lculation the GSM were incorrect. - The Inspectors also noted that the APM failed to enter the fallsafe mode (by extinguishing the amber !!ght) at the fallsafe point marked-
. on the front of the monitor readout.
Response
Prior to any attempts to operate the reactor for the purpose of locating the -
source of the fuelleak, the CAM, APM, and GSM will be recalibrated.
Paragraph 2.0.d: PersonnelExposures The inspectors noted that "...the operators initially respend!n1 to the event madu four entrieo into the reactor bay after the initial CAM a' arm. " hose entries were made without respiratory protection.... -
1 4 Inspection on November 24 December 4,1991 (Re d conducted by P Qualls, J. Melfi, J. H. Reese of NRC Reelon Vport No. 60 288/91 01),}
q Reed Reactor Facility Reetart Plan March 17,1992 P. age 2 j
. o
Response
Prior to any attempts to operate the resotor for the purpose of loosting the source of tie fuelleak, the Reed Reactor Facility will procure roeplrators equipped with activated charcoal filters for ute should redloactive lodine be detected. These will be made available to the facility ettff, as needed, alon with protective clothing.-~ Only' essential personnel will be allowed into the : 0 '
Reactor Bay during operations.
PrenaraCans Raoutred hv Lleanna Amendment Number 80 As indicated above, Amendment Number 5 to Paollity Lloonee No. R 112 - Reed College Reactor Facility walved the time periodicity requirements for Technloal Specifications survellfances E.3, F.2, F.9. and F.10. The amendment also stated that 'these survelliance requirements must be completed prior to retum to-routine reactor operations."- Some of these surveillances will be completed -
before the faollity staff begins to operate the Reactor Foollity for the purposes of locating the source of the fuel element leak, and some will 2 done after the leak is located but before we resume normal operatione: -
Technical Spednontion Paragraph E.3 "Each standard fuel element shall be visually inspected at least once overy five years.- At least 1/5 of all the fuel efements of the core shall be inspected at voarly Intervalo. If Indication of apparent deterioration or distortion is found, the "uel element (( shall be removed from the core.'
Response
Each fuel element removed from the core during Step 2 of the process described below will be visually inspected prior to replacing it in the core. - After +
the leaking element is identified, but before we resume normal operations, an -
Inventory will be made of any additional elements which are due for inspection .
and these inspections will be performed.
- a Technical SpeclMcations Paragrapit F.2 "The control elements shall be visually inspected at least once every two years, if Indication of significant distortion or deterioration is found, the element (s) shall be replaced."
Response
This will be done after the leaking sternent has been identified, but before we: '
resume normal operations.
~
Technical Spedlications Paragraph F.G.a.
" Verification that all control element drop times are i.e inan one second....'
Reed Reactor Fic!!!ty Restart Plan March 17,1992 ,
Page 3
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Response
This w!Il be done before we operate the reactor for the purpose of locating the leaking fuel element, concurrent with the daily Startup Checklist.
Technical Spect!! cations Paragraph F.9.b
'A functional test of the ventilation system lnterlocks....'
Response
The ventilation system Interlocks are not related to the touctor control systema.
We have been performing functional tests as required by the Technica.
Speelf! cations. This will b0 done again before we operate the reactor for the purpose of locating the leaking fuo' element.
Technical Specifications Paragraph P.10 "The linear power level channel shall be callbrated et least annually by thermal power calibration."
Response
, Because the procedure for performing a thermalpower calibration requirse us b operate the reactor for 6 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> at high power, this should not be done watil the leaking fuel e:ement has been located and removed. This will be done after the leaking element has been identified and rem;ved, but before we resume normal operatione.
Additional Prena'ations' Facility StafMng:
On March 1,1992, Paul Tordal, a former student and currently a licei ,
Senior Reactor Operator, was hired as Associate Director for the Reamor Facility on a full time bas!s.
AirParticulate Monitor (APM):
The samp!!ng/ detection module for the stack particufate monitor (APM) should be moved from its current location in the reactor room to a location where it wlil not be influenced by increases In reactor room radiation backc cund.
Relocation should also consider shleiding the detector in this module. Before the reactor le operated for the purposes of finding the source of the fueJ leak, the APM sampling / detection module will be move (! out of the Reactor Roqm and into the exit corridor, as shown in Figure 2 below. A shelf for lead bricks will be Insta!Ied in the Reactor Room to provide shielding for the detector.
Continuous Air Monitor (CAM):
Reed Reactor Facility Restart Plan . March 17,1992 Page 4
The CAM air Intake le currently located in a pipe trench running from the Reactor Bay to the Mechanical Room. During isolation mode, there le a pressure differential between these two rooms, resulting in a steady current of air from the Mechanical Room to the Reactor Bay. Thle could affd the CAM readlr gs. The air intake will be moved several feet to that it la cui of the path of this stream of air. See Figure 2.
We w!!! also Install a new remote readout for the CAM in the control room, where it can be read by a console operator. ,
Health Physics Precautions:
Following the recommendations in the General Atomio TRIGA Mark l Reactor dochanical Maintenance and Ooeratina Manual, the reactor pocl will be sealed as much as is possible to limit the esca se of radioactive gassa. This Will also maxim!ze the concentration to the CAM. ihe pool will be covered by a plastle tarp, which will be tapod or sealed around the edges! the Rotary Specimen Rack dro tube will be taped shuti and the Central Thimble will bo sealed. When man ulating the water sniffer, however, the covers will be opened as needed r ease of handling.
Only essential personnel will be allowed in the Reactor Bay during operations, and personnel time in the bay will be minimized, full face respirators with charcoal activated filters will be made available, as needed, for facility staff working in the Reactor Bay. Personnel radiation doses will be monitored to er2ure that they do not exceed the limits specifled in 100FR20 orin the Reed College Administrative Procedures.
Air Monitonng:
Additional alr monitoring capability will be available for thle testing period:
- 1) A low volume alr sampler equipped with a charcoal cartridge for lodine determination will be operated in the reactor bay. Samples will be collected at routine Intervale and analyzed for partloulate and lodine activity in the room air.
- 2) An air sampling device for noble gases has been developed which consists of a 1 liter flask and stop cock. This flask can be evacuated with a vacuum the stack.The pump andthen flask can thebeflask filled sealed andwith alt for counted either noblefrom gas the reactor bay or activity on either a Ge detector or Nal crystal connected to a multichannel analyzer.
- 3) The Oregon State Health Division, Radlathn Control Program,~ivill be informed of testing times so that they may,if they deem it appropriate, collect Independent samples outside the facility.
Requalification:
. Reed Reactor Facility Restart Plan March 17,1992 Page 5
Our Requallfication Plan and Procchures submitted to, anti approved by the NRO, require operators to opend four hours performing the functions of a Econsed reactor operator during each calendar quarter. Concem has been ra! sed about whether operators will be delinquent in requallfication requirements if the reactor le not operated until after ,'pril 1,1992. According to our procedures, actMiles whloh may be counted towarde thle four hours include not only actual reactor operation, but also tirte opent In completion of routine
' checklists, loading and unfonding sampfes from the reactor and maintenance of the reactor or any of its systems. We currentfy have four lloensed eenfor reactor operators who are actively involved in such operatione. ReactMty changes (10) must be comp!0ted w!!hin a reporifng year and all operatore should meet these requirements easily by the end of this year (September 1, 1992).
i Procedure for finding fuel leak:
The procedure outlined befow for detection of faulty fuel elements la based on that contained in the TRIGA_ Mark l RoaciQL Mechanical MaintQDance 'and Operatino Manue] for Reed College, with some additions based on elmilar i
experiences at other faollltles.
Stan t Operate the Reactor, and Search for Flaslon Producte In this phase, we will operate the reactor at the lowest power level that will produce a reasonably detectab!e amount of fission product. The ventilation .
system will be placed into isolation mode before operations begin. The Startup Checklist will verify proper operation of control rod microswitches noted to have been m!sadjusted at shutdown on November 23,1992. Following the advice in the GA Mechanical Maintenance and Operating Manual, and the experience at the University of Utah, we w!Il attempt to use a water "sntffer"(descrbed in more detall below) to track the source of fission products in the pool water to a
' speelfic element or region of the core. This sniffer will draw sampfes of water from the area lmmediately above the top grid ptate past :Jal detectors located in the reactor bay. Detalls on the water sniffer are discussed below, i Water Stdffer:
This water snifferis based on recommendations from General Atomic and the recent experiences at tne University of Utah. Water la samp!ed from each fuel element opening in the top grid plate by placing a small funnel over the top of each o!sment,in turn, and pumping at low volume through a 150 ft section of 1/8' to 1/4' plastic or Tygon tub 1ng. This tubing is then wrapped around a Nal detector, wnich is connected to a ratemeter and a Multichannel Analyzer, and is used to directly measure the types and quantities of radionucildes in th_e water.
See Figure 1.
The tubing and funnel would be mounted to a light weight aluminum which would be used to position the funnel over the tops ements. of the fuel s' pole, The reactor would then be operated at a constant power levelin order to Reed Reactor FacWty Restart Plan March 17,1992 Page 6 <
a . . !
l produce some leakaos, in addtion to the prinalple funnel designed to et over one fuel element at a time, a larger funnel will be available whoh would allow ;
for samote water from several elements at once in order to Snd a General f*glon-or the o' ore that is releasing floelon products. The individual operatin0 the eniffer would attach one funnel or the other, se needed.
Attal Remove suspect fuelelement :
Once a suspoot fuel element or group of fuel olomonte le identlfled, the element .
or elements will be removed one at a time and inspected vi (through the -
existin0 perisoops or other means for visible signs of damage. e reactor will Jis? be operated at the power leve)l used 1, with in Ste the CAM and the sniffer :
he% used to detect gaseous emissions, if no lurther emissions are detooted, ,
tnen the resolor power level will be increased to maximum in small increments ;
over time, if no further emissions are deteoled, then the problem will be considered to be resolved. !
If the above stops prove unsatisfactory, then other approaches, such as swapping out e;ements in groups and operatinp the reactor until the problems disappear, will be considered by the foollity sta1 ' to locate the source of the leak, i Rasumptlon of Normal Operations:
After the faellity staff has concluded that the problem has been resolved. the -
staff will report its findings and justify its conclusion to NRC Region V. When
- NRC Region V has concurred with 11e findings of the feell!!y staff, we will do the -
- following final preparations before declaring the reactor ready to resume normal .
operations: .
Fuel Element inspection of all elemente scheduled for this year, as required by Technical Speelfications Paragraph E.3, that were not ,
inspected during the process of locating the source of the fuelleak.
Control Rod Inspection, as required by Technloal Specifications ;
Paragraph F.2 '
Calibration of all control rode Linear Power Calibration, as required by Technical Specifications Paragraph F.10 .
(see Preoaratlana Raoutrad by Lleanna Amendment Number 5. above).
After these final preparations have been completed, the resolor will be
, considered ready to resume routine operations, at the discretion of the Director of the Reed ReactorFacility.
r Reed Reactor Facility Restart Plan March 17,1992 Page 7
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A - Dwoome weer ,
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- Motiohannel Typen WW '
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Reamor Core 4
Reed Reactor Facility Restart Plan March 17,1992 P*ge8
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Figure 2 Poaltion of APM. CAM Afr intaka ammmmmmmmmmum mumme manusumummme ammmmmmmme CAM =
i Proposed l Fauro CAM Ak '
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l g intake comAOL som , trAcTan RDDM
- cent Apu Loosten
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I D llEl N- Faute AFM Location
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TX11 CotRIDOR 4
Resd Reactor Facility Restart Plan March 17,1992 Page 9
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