ML20126E735
| ML20126E735 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 10/27/1992 |
| From: | Fleming R MICHIGAN, UNIV. OF, ANN ARBOR, MI |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9212290290 | |
| Download: ML20126E735 (39) | |
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e, s University of Michigan Michigan Memorial-Phoenix Project Office of the Director '
Ann Arbor, Michigan 48109-2100
. 1 October 27, 1992 :
Docket 50-2 License R-28 United States Nuclear Regulatory Commission Regica III Attn: Charles Norelius 799 Roosevelt Road Glen Ellyn. Illinois G0137 ue: Reportable Occurrence 15:
- 1. Scotiarios Involving Unant.icipated Reactivity Insertions in the Ford Nuclear Reactor Core;
- 2. Facility procedure Review and Modification; *
- 3. Technical Specification Review and Modification.
Dear Mr. Norelius:
This is in response to the commitment to evaluate the effects of unanticipated reactivity insertions in the Ford Nuclear Reactor Core, t.o conduct a thorough review of facility procedures, and to conduct a thorough review of Technical specifications.
- 1. Scenariou Involving Unanticipated Reactivit.y Insertions in the Ford Nuclear Reactor Corci 1.1 Experiment. Inse r t. ion /Wi thd rawal From t.he Ford Nuclear Reactor Core While Critical The most reactive experiments in the Ford Nuclear Reactor Core am capsules containing steel specimenu that are irradiated in core grid position 67. The capsules can be irradiated two-at-a-tifie.-
The reactivity of a capsule pair varies with core configuration and, in particular, with the number and uranium burnup of fuel elements surrounding position 67.
The nominal magnitude of the reactivity of the steol-specimen capsules is 0.005 delta K/K. Reactivity is negative when the capsules are inserted and positive when they are withdrawn.
Experiments with reactivities greater than 0.0012 delta K/K are secured and cannot be moved during reactor operation. If the securing mechanism were removed and a capsule pair were extracted while the reactor was critical at power, the positive reactivity inserted would be below the prompt critical value of 0.0075 delta K/K and well below the Safety Analysis limit of 0.016 delta K/K.
Core damage will not occur if the Safety Analysis limit is not exceeded. ,
9212290290 921027 PDR ADOCK 05000002 6 PDR. ,
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United States-Nuclear 10 gulatory Commissior !
October 27, 1992 The worsi possible scenario is as follows. The securing mechanism for the capsules is removed. The capsules are removed at power. !
The speed with which the capsules can be withdrawn is relatively l slow because of their configuration and close tolerance with their !
holder. During withdrawal, reactor power increases on a period i greater than 10 seconds, the shim-safety rod automatic rundown ,
setpoint. At a power level of 2.3 megawatts, a rundown occurs and the three shim-safety rods insert at their normal speeds. If a power level of 2.1 megawatts is reached, the reactor scrams and <
all three shim-safety rods drop into the core with minimum magnitude of negative reactivity equal to 0.025 delta K/K. ;
1.2 Fuel insertion in the Ford Nucicar Reactor Core ,
l A series of measurements have shown the nominal range of ,
reactivity values of new fuel elements around the perimeter of the Ford Nuclear Reactor core to be between 0.0030 and'O.0125 delta 1 K/K. In the interior of the core, the nominal maximum reactivity of a new element exceeded 0.0327 delta K/Ki it was not possible to bring the reactor to criticality with the new element removed to measure its actual reactivity. The reactivity of a slightly ;
depleted element (148.62 gm U-235 vice 167 gm U-235 in a now :
element) in the most reactive interior location, grid position 37, was 0.0315 delta K/K. The reactivity of a new element can be :
approximated by assuming that the reactivity per gram of U-235 is !
constant. The reactivity of-a new, 167 gm element in core grid position 37 is approximately 0.0354 delta K/K.- 1 Since the Ford Nuclear Reactor operates with all core grid >
locations filled with fuel elements, experiments, or cylindrical plugs, it is not possible to insert fuel elements into the core 1
when the reactor is operating.
During refuelings of the Ford Nuclear Reactor,.the reactor _is shut down before refueling begins. The magnitude of the shutdown ,
margin with all three shim-safety rods inserted is at least o.325 delta K/K. The removal of a depleted element and replacemenc with a new element in any perimeter location would add positive reactivity that is only a small fraction of_the shutdown margin.
Measurements showed the maximum positive reactivity insertion as - t the result of such a fuel element exchange was 0.0035 delta K/K when a new, 167 gram U-235 element replaced a depleted, 121 gram U-235 element in core grid position 40.
Before refueling takes place in the center of the core, elements are removed from the core perimeter until the magnitude of.the
- shutdown margin is increased to at least 0.0526. That ensures the reactor will remain subcritical if: (1) a fresh element is exchanged for a depleted element in the most reactive interior core-location and (2) a fresh element is exchanged _ for an experiment holder or a cylindrical plug in an interior _ location.
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i United States Nuclear Regulatory Commission r October 2?., 1992 Following refueling, all core grid positions are inspected to !
ensure that they contain fuel elements, experiments, or [
cylindrical plugs.
During the refueling process, it is not possible to make the Ford ;
Nuclear Reactor supercritical by inserting fuel elemnets in the core, 1.3 Shim-Safety Rod Inspection prior to removal and inspection of shim-safety rods from the Ford Nuclear Reactor core, fuel elements are removed from the core grid i until the magnitude of the shutdown margin is increased to at least 0.100 delta K/K. The nominal reactivity of each shim-safety '
rod-is 0.020 delta K/K. Shim-safety rods are inspected one-at-a-time, but_ oven if all three rods were removed together, the magnitude of the shutdown margin would:still be between 0.030 and 0.040 delta K/K.
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lt is not possible to make the reactor supercritical during shim-safety rod inspectionn.
- 2. Ford Nuclear Reactor procedure Review and Modification A thorough review of all facility procedures was conducted. The following is a-bric" summary of modifications made as a result of the review. While the modifications have been approved for '
implementation, complete implementation for some of_the procedure modifications will require additional time.
2.1 Adtn1rdE.trative procchtten Ap-101 procedure _preparati'n Added the specific responsibilities of the Shift Supervisor and the Shift operator.
Provided clarification on the content of_the safety ,
precaution, prerequisite, and procedural sections of procedures. 3 Added the date_-to the revision #-on the top right-hand corner of procedures. -
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United States Nuclear Regulatory Commission October 27, 1992- -
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- 4 i AP-301 Reactor Fuel 'j Tag out required for fission chamber positioning switch
- rather than tape.
Two individuals verify fuel element number and proper 1 seating of fuel elements in the-core during fuel !
movements. -J i
Console operator verifies that all core grid :
positions are filled at completion of movement.-
l AP-302 Critical Experiment Perform the experiment in four stages. One shim-safety rod is withdrawn to set up condition A. .
This rod remains out for the rest of the.. experiment.
A second is withdrawn to condition D. The third is !
withdrawn to condition C. The control rod is- 4 withdrawn to condition D. If the reactor is still suberitical, the control rod and two shim rods are ,
inserted. This ensures that the net core negative -
.l reactivity is at Icast -0.042. delta K/K which
- satisfies the rechnical specification shutdown-margin requirement of -0.025 delta K/K and 1s-more negative than the positive reactivity of a new fuel element inserted anywhere in the core. At this '
point, the next element is loaded and the rod :
withdrawal sequence i s repeated. ,
AP-401 Contacting the on-Call Supervisor j If in the opinion of the Shift Supervisor a situation -
exists that warrants immediate action, the action is taken before the On-Call Supervisor is' contacted.
Y AP-404 Fire Protection Equipment Inventory
-Verification of operation of three smoke detectors and t.he basement emergency light _has been added.
2.2- G.n.lijj.rA1.lon and Malritor111 pee procqdgren CP-101 Reactor Maintenance Schedule' l Responsibilities of Shif t Supervisor and. Shift operator defined. ;
Replacement of batteries in Emergency Closet instruments added to annual maintenance items, i
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United States Nuclear Regulatory Commission October 27, 1992 l r
.CP-201 S' nim-Safety Rod Calibration l Responsibilities of Shift Supervisor and Shift Operator l defined.
CP-202 Control dod Calibration ,
Responsibilities of Shift Supervisor and Shift Operator defined. t I
Reactor prestart checks completed.
llender up.
Cp-203 Rod Release-Drop Time Measurement ,
Responsibilities of Shift Supervisor and Shift Operator defined.
1 Expanded and clarified content. !
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CP-204 Defeating Reactor Scram Interlocks procedure will be eliminated because these scram
- functions will be removed.
Cp-206 Log N Channel Calibration-Responsibilities of Shift Supervisor and Shift Operator defined.
Check of 5% power scram functions and'30 and 10 second period rundown functions clarified.
CP-207 Linear Level Channel Calibration :
Responsibilities of' Shift Supervisor and Shift operator defined. ;
Calibration of spare range selector clarified.
Test of the automatic _ control unit clarified.
. Automatic controller.-- functions recorded. ,
CP-208 Log Count Rate System Calibration l Responsibilities of Shift Supervisor and Shift operator ~
defined.
Initial conditions clearly defined.
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F United States Nuclear Regulatory Commiasion October 27. 1992 ;
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CP-209 Calibration Check of Linear Level, Log N, period, and Log Count Rate Systems Responsibilities of Shift Supervisor and Shift Operator defined.
CP-210 Servo Control Settings
- Responsibilities of Shift Supervisor and Shift Operator defined.
CP-212 Low Flow Scram Verification Responsibilities of Shift Supervisor and Shift Operator defined.
CP-211 Temperature System Calibration Responsibilities of Shift Supervisor and Shift Operator defined. J CP-213 Primary and Secondary Flow System Calibration n
Responsib111 ties of Shif t Supervisor and Shif t Operator:
defined.
CP-215 MMC Model GA-2TO Area Monitor Calibration Responsibilities of Shif t Supervisor- and Shif t Operator defined.
Test switch to bypass CP-301 Shim-Safety Rod Inspection Responsibilities of Shift Supervisor and Shift Operator defined.
Add step to review the procedure.
Cp-302 lon Chamber Replacement Responsibilities of shift Supervisor and Shift operator
. defined.
Specific step to reconnect all leads for normal operation added.
CP-303 Fission Chamber Replacement-Responsibilities of Shift' Supervisor and-Shift' Operator defined.
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United States Nuclear Regulatory Commissio.1 October 27, 1992 CP-304 Electromagnet Replacement Responsibilities of Shift Supervisor and Shift Operator defined.
CP-305 Cooling Tower Maintenance Responsibilities of Shift Supervisor and Shift operator defined.
Clarify oil viscosity used.
CP-308 Equipment out of Operation The procedure was renamed and modified to include not only failed equipment but any equipment put out of operation. A tag out requirement was added for both mechanical and electrical equipment.
CP-402 Primary System Demineralizer Delete the procedure.
CP-403 Cold Demineralizer System Delete the procedure.
CP-404 Pool Vacuum Procedure Responsibilities of Shift Supervisor and Shift Operator defic.ed. ;
CP-408 Thermal Column Door Operation Delete the procedure. ,
CP-502 Reactor Pool Water Surveillance The evaporation rate fraction for pool water that leaks through pool wall cracks was adjusted based on eleven pool water surveillances conducted over two years. An uncertainty of 20% in the leakage eva oration rates was estimated.
CP-602 Emergency Generator Check Responsibilities of Shift Supervisor and Shift Operator defined.
Proper positions of function switch for generator start and test switch for loud testing the generator clearly stated.
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d United States Nuclear. Regulatory-Commisslon-October 27. 1992; ,
2.3 - Managengjtt . Procciqr.nu !
MP-201 Facilit.y Access Control, Personnel Radiation Monitoring- l Equipment, and Instructions tol Workers Clarification for opening and locking entranco doors J provided since working day bours change slightAy from winter to summer.
Reactor third floor acceau door requires electronic key except when the reactor is operating, ;
Personal-conduct in the facility and-ir, the control' room j added to the instructions to workers.
Hp-401 Reactor Experiment Review Experiments may-be reviewed by a designated.Indiv'idual.: 1 This will allow review by reactor operators as '
suggested by the TRTH review.
Section number corrections for references to ;
Technical Specifications.
2.4 Qumttcing proceduran Op-101 Reactor Startup Respor sibilities of Shi f t Supervisor and Shif t Operator de fi ned .
Console operator review the procedure before startirig. ;
Record completion of startup checklist in the reactor ,
logbook.
Sample holders replace grid plugs to fill. empty spaces $
in the core grid.
For all full startups, power will be-held at 500 kw andL ir check of: instruments conducted. ,
startup_ checklist. clarified to'make each step a: single-action.
A range for.the cycle initial critical shim-safety '
rod-height has been added to provide operator-guidance.
Excess reactivity limit changed to-new Technical-Specification value of 4.36% delta K/K.
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i United States Nuclear Regulatory Commission ,'
October 27, 1992 i
Op-102 Reactor Shutdown !
Responsibilities of Shift Supervisor and Shift Operator defined.
Clarification of some steps provided.
4 Op-103 Henctor Operation. .4aintenance, Systems, and Components Responsibilities of Shift Supervisor and Shift Operator ,
, defined.
Shift turnover requirements strengthened. Formal shift turnover required for end of shift and mid shift. When the second peraon on shift is not licensed, a formal turnover is not required for-bathroom reller of the .
licensed person on shift. The relief must have a license and must-sign in as the console = operator.
Fn11ure and removal from operation of equipment and instruments must be logged in the reactor logbook.
power level changes related to reactor safety may be done by the console operator without specific authorization from the shift supervisor.
The shift supervisor is responsible for and must authorize fuel movements. ,
Op-104 Reactor Experiments and Cobalt-60 I rradiations Responsibilitics of Shift Supervisor and Shift Operator
, defined.
The reactivity magnitude and arithmetic sign during insertion are recorded on the reactor ut.111:ation request. ,
Op-105- Core Excess Reactivity, shutdown Margin. Control Rod Reactivity, and Verification of Core Negative-Reactivity Equa.1 to or Greater Than l~0.10K/K-Verification of core negative reactivity has been made a separate procedure.
Responsibilities of Shitt Supervisor ~and-Shift-Operator defined.
Console operator review the procedure and verify the conditions for startup are met. ;
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United States Nuclear Regulatory Commission :
October 27, 1992 ;
Core excess and shutdown-margin are calculated with secured experiments loaded.in the core and with secured experiments removed. This permits removal of secured experiments in mid-cycle i f required, without the ,
necessity to reverify shutdown margin and excess j reactivity. !
t OP-100 power Level Determination l Responalbilities of Shift Supervisor and shift Operator 1 defined.
h'a rn i ng to not let temperature reach the 129 *F rundown ;
point. 7 Op-107 lon Chamber Adjustment procedure Responsibilities of Shift Supervisor and Shift Operator-defined.
Review the procedure and ensure the reactor is in-automatic.
Obtain specific permission from the console operator to cdjust chambers.
If linear icvel is adjusted, match the-controller setpoint to indicated power'before returning to automatic.
Op-108 Filling and Draining Reactor Beamports Responsibilities of Shift Supervisor and Shift Operator defined.
Review the procedure.
Console operator grant specific permission and-monitor the. stack.2_ GAD during f1111ng.
Op-109- Response to Scrams. Alarms. .and Abnormal Conditions New procedure _to provide guidance for operatorsLas-suggested by the TRTR review. _. -
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Op-110 Verification of the Magnitude of Core Negative .
Reactivity Equal to or Greater.than 0.10 delta _K/K _ !
4 New procedure separated from Operating procedure _105, d=
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- United States Nuclear Gogulatory Commission October 27, 1992 l
- OP-201- Building Checklist .l
. Responsibilities of Shift Supervisor and shift Operator !
defined. ;
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Normal air system pressures adjusted to conform to system description. i Surveillance requirements for the Phoenix Memorial .
Laboratory building deleted based on modification to i facility security plan.
OP-202 Fission Chamber Response Check Responsibilities of Shift Supervisor and Shift Operator defined.
Op-209 Primary Coolant Pump Operational Rotational .!
New procedure separated from being-part of Operating Procedure 103.
Op-301 Building Power Failure Responsibilities of Shift Supervisor and Shift Operator defined.
' Clarification of reset requirements for some items '
provided, Op-302 Nitrogen Supply System Operating Procedure- l Pressure equalleation clarified.. -
- 3. Ford Nuclear Reactor Technical Specifications Review and >
-Modification A thorough review of Technical' Specifications was-conducted.- The following significant modifications will be submitted as1 Amendment
- 38. _-A' number of additional typographical corrections and clarifying statements will be submitted that will not be substantive changes to the-intent-or content.
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-United States Nuclear Regulatory Commission October 27, 1992-Technical Specification Section 3.1.1 i
The shutdown margin relative to the cold, clean critical i condition shall be at least 0.025 delta K /K , - e x c e p t ditti.ng the process of verifying shutdown margin.
Comment:
This will allow the operations crew to measure shutdown margin prior to going to power without violating Technical Specifications. If the shutdown margin is inadequate, fuel can be added or removed to establish the proper shutdown margin.
1 Technical Specifications 3.1.3 and 3.1.4 The reactivity worth of experiments shall be- limited as follows, su: cent during the process of verifyinst experime_n1 i n wetivits Maximum Ex pe r i tur.D1 - Reactivity Worth Individual Moveable 0.0012 delta K/K Individual Secured 0.012 delta K/K Total Moveable and Secured 0.012' delta K/K Comment:
These modifications will-allow the operations crew to measure experiment reactivities prior to going to.-
_ power. If the reactivities are too large,-the experiments can be reclassified or removed as appropriate.
Technical' Specification 3.1.5 The reactor shall be suberitical by at least 0.025 delta K/K-during-fuel movements.to and f rom the _ reactor core.
Comment:
This makes it. clear that;any fuel movement to or from the core requires the reactor to be adequately
- shutdown. The way tnat-the revised critical loading
!. experiment will be conducted will meet this-requirement.; Fuel movement is permitted within the pool from rack to rack when the reactor is operating.
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United States Nuclear Regulatory Commissi.
October. 27,_1992 Technical Specification 3.2, Table 3.2 The radiation monitor associated with the primary demineralizer has been deleted. Conceptually, its function was to monitor for fission r oducts in the primary domineralizers and to monit the facility's " cold sump".
The three fission product leaks that have occurred were never seen in the hot dominera112ers; they were detected by airborne and pool water *.nalyses. Many years ago, the " cold sump" pumped directly to the city sewer system. That ability has been disconnected. The " cold and hot sumps" ,
both collect potentially radioactive water, and-they both pump to the retention tank system from which the water is recycled back to the reactor pool.
Sincerely, 4f>
Ronald F. Fleming, Direct r Michigan Memorial-Phoenix Project xc: United States Nuclear Regulatory Commission Document Control Desk Attn: Theodore S. Michaels, Project Manager Non-Power Reactors, Decommissioning, and Environmental Projects Directorate Division of Reactor Projects III, IV, and V Office of Nuclear Reactor Regulation Washington, D.C. 20555 Safety Review Ccmmittee Members Safety Review Cummittee File ,
Reactor Operations Staff Vice President for Research 13
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a NUCLEAR ' REACTOR LABORATORY -
- THE UNIVERSITY OF M1Cll10AN 2301 Bonisteel Boulevard Ann Arbor, Michigan 48109-2100 (313) 764-6223 k
APPENDIX 1 Ford Nuclear Reactor
_ University of Michigan Corrective Actions Completed and Planned Relatedito E._ Reportable Occurrence 15, Removal of a Fuel Element g- From the Ford Nuclear Reactor Core While Critical h!1 Rr September 14, 1992
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. Appendix 1 Reportable Occurrence 15 Corrective Actiona September 14, 1992
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Completed and Planned Corrective Actions Related to Thone Items Identified by~the Univeralty and by the Nucicar Reguintory Commission The following changes in the reactor operating procedures, operat or supervisory responsibility, and operot.ing schedule have been implemented.
- 1. procedure Changes Related to Fuel Movement and Reactor Opernt. ion 1.1 Fuel Moventen1_.AnzwAnr1 In_1he nenctor P_aal .
The following changes have been made to Administrative Procedure 301', Reactor Fuel. The changes have been incorporated as steps in a checklist that is performed and initialed as the first and last steps in the fuel movement procedure. At present, these changes
! have been extended to apply to the movement of all fuel in the l
-reactor pool, not just the movement of fuel in and out of the reactor Core.
L Ensn.Lo_..anv fne LmoyemeEl y
l- In the control room:
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- 1. Shim-safety rod control switch in LOWER position.
- 2. Shim-safety rods fully inserted.
I 3, Shim-safety rod lower limit lights on.
- 4. Magnet power off.
- 5. Fuel handling tool lock key given to fuel handlers.
On the reactor bridge:
- 1. Sh.im-safety rod position indicators at sero inches.
f 2. : Fuel'hanoling tool unlocked and removed from its i~
secured storage position, l
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l I Appendix 1 j
1 Reportable Occurrence 15 Corrective Actions September 14, 1992 ciffn,r comolq,tdan of any ,[qpl raovement and before reactor 1.t a C1.Mlli on the reactor bridge:
- 1. Fuel handling tool returned to its secured storage position and locked in place.
In the cont.rol roem:
- 1. Fuel handling tool lock key returned to console operator.
- 2. Magnet power on.
In addition, for fuel movements to or from interior core locations, the following condition will be observed:
Verify that the magnitude of core negative reactivity is equal to or greater than 0.05 delta K/K.
Interior core locations are defined as all core positions except the east, west, and south faces of the core. East, west, and south faces of the core correspond to core grid position numbers 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 76, 77, 78, 79, and 80).
The minimum shutdown margin for the reactor with all shim-safety rods inserted is .025 delta K/K. However, the most reactive fuel element in the core, in grid location 37, has a potential positive reactivity value in excess of 0.04 delta K/K. prior to removal of fuel from location 37 and other high reactivity areas in the interior of the core, fuel elements will be removed from the core periphery to ensure the magnitude of the core negative reactivity is equal to or greater than 0.05 delta K/K.
Subcritical multiplication techniques will be used to determine the final negative reactivity value; the ratio of suberitical counts with the shim-safety rods fully inserted to the final suberitical counts must be greater than two.
In the past, solid nose cones called plugs were inserted in empty core grid locations. These devices still permitted a fuel element to be partially inserted into the same location. In order to prevent mistaken insertion of a fuel element in an open core grid location, full length cylindrical plugs have replaced the shorter, nose-cone type plugs. Prior to reactor criticality, every core grid location will be filled with fuel, experiment and sample holders, or the new cylindrical plugs. Positive reactivity additions to the core as the result of fuel insertions will not be possible. Tae only possible positive reactivity additions would come from experiment insertions. The maximum positive reactivity value from an experiment, even if inserted into a critical reactor, will never exceed the Safety Analysis limit for which core damage could occur.
Appendix 1 Reportable Occurrence 15 Corrective Actions September-14, 1992' .
The following changes were implemented in Administrative Procedure 301, Reactor Fuel, prior-to the Nuclear Regulatory _ Commission- 4 inspection.
When fuel handling is-in progress, no other evolutions involving rod movement, in-core experiments, or core reactivity will be conducted.
Verify with the control room operator just prior to loading fuel into the core or unloading fuel from the core that the loading / unloading may proceed. Fuel elements may not be moved into or out of the core unless verbal approval is received for each and every movement.
1.2 Operator Supervisorv Responsibility As a result of an evaluation of the work load at the Ford Nuclear reactor facility, a sharp division between operator responsibility for the safe operation of the reactor and responsibility for experimental, training, and maintenance activities has been established.
Each shift has two operators, one of whom must have a senior license, whose sole responsibility is the safety of the reactor.
The on-shift crew will specifically supervise and authorize all activities including manipulation of experimental facilities,
-training, maintenance, fuel movement, and any activities involving
-core reactivity.
A third operator will_be assigned the responsibility for conducting activities such as training and fuel movement. For example, if the Reactor Manager is conducting a demonstration startup for a class, the senior reactor operator on shift will'be in the control room supervising the startup that is being
-conducted by the Reactor Manager. As another example, if the Assistant Reactor Manager is conducting fuel loading, one of the
.icensed operators on shift will be in the control room sapervising and authorizing specific fuel movements.
The objective of this division of responsibilities is to separate the individual who has a particular interest in the success of an evolutton from the individual who is responsible for reactor safety.
This division of responsibilities has been incorporated in Operating procedure 103, Reactor Operation, in Section 5, Operation at Power, and in Section 9, Maintenance During Reactor Shutdown.
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Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992 1.3 procedure Changes Related to Operator Shift Responsibility Operating Procedure 103, Reactor Operation, contains detailed requirements for shift turnover, both at the beginning of a shift and during the shift. In order to ensure that it is perfectly clear who is directly rewponsible for shift evolutions, the following additional statement has been added:
The senior reactor operator and the reactor operator who are logged in to the reactor logbook are responsible for the specific authorization and supervision of all reactor evolutions and activities.
While this requirement has been policy at the reactor, it will be specifically stated in Section 3 of each facility procedure.
Section 3 delineates the responsibilities of the senior reactor operator and the operator on shift.
1.4 Procedure Review and Ery Runs On July 1, 1992, the entire reactor operations staff (management, senior reactor operators, and reactor operators) held a four-hour training session to review proposed changes to:
Administrative Procedure 301, Reac tor Fuel Operating Procedure 103, Reactor Operation Prior to fuel movement and restart of the reactor on July 2, 1992, all operations personnel who were involved with fuel movement related to the restart conducted a dry run of the revised fuel movement procedure. By July 17, 1992, all reactor operations personnel, except two who were on vacation, had conducted a dry run of the revised fuel movement procedure. Those two have subsequently reviewed and performed the procedure.
1.5 Critical Loadine Experiment Administrative Procedure 302, critical Loading Experiment, will not be conducted until technical specification and procedural questions can be resolved between the University and the Nuclear Regulatory Commission.
- 2. Reactor Operating Schedule The reactor operates on a fixed cycle at its licensed power of two megawatts. The cycle consists of ten days at full power followed by a shutdown of four days for maintenance. The current ten day operating perfod was from Tuesday of one week to Thursday of the following week. Maintenance was done on the following Friday and Monday. Very little maintenance can be
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l 2 Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992 ,
accomplished on Friday because levels of radiation are still high from reactor operation and fission product xenon dominates core reactivity. This is especially true for work that requires accurate determinations of reactivity.
The operating schedule has been shifted to startup on Wednesday of one week and operation until Friday of the following week. This schedule allows the reactor to " cool down" and " decay" over the weekend. Maintenance is carried out on the -following Monday and Tuesday. This change provides additional regularly scheduled time for performance of maintenance procedures that require reactivity checks. In addition to the radiation and xenon advantages, the same shift personnel are on duty Monday and Tuesday to provide continuity.
Implementation of the proposed operating schedule requires the payment of overtime to operators because a federal wage and hour law
" work week" starts on Sunday, runs to the following Saturday, and consists of 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />. Under this operating schedule, the first week of operation has 32 work hours and the second week of operation has 48 work hours. The advantages of the schedule merit the additional cost of overtime.
- 3. Review of Procedures and Technical Specifications A commitment was made to conduct a thorough review, and revision if necessary, of all facility procedures and the reactor technical specifications. The review was to be completed within 60 days of Junc 26, 1992 and revisions were to be completed within 90 days.
The review has been completed. Revisions will require more than an additional 30 days because of the process followed by the facility:
(1) nroposed revisions inserted into procedures; (2) re-review by the reactor operations staff; (3) incorporation of final revisions;-
(4) Safety-Review-Committee review and approval; (5) final implementation.
- 4. Evaluation of Reactivity Insertion Scenarios A commitment was made to evaluate potential scenarios involving fuel movement and reactivity insertions in the reactor core. Fuel element reactivity measurements have been made at many core
. locations as one of the steps in this process. Scenarios for improper movements of fut; and experiments and their impacts are being considered. Documentation of this evaluatien was to be completed within 90 days of June 26, 1992.- The final documentation likely will require some additional time.
- 5. TRTR Review of Reactor Operation A review of the operation of the Ford Nuclear Reactor was conducted by three reactor administrators from the Training, Research, and Test Reactor (TRTR) organization on July 8-9, 1992.
Appendix 1 Reportable Occurrence 16 Corrective' Actions
-September-14, 1992 Completed and Planned Corrective Actions Related to Those Items Identified by the Training, Research, and Test Reactor (TRTR) Organization Review The following section numbers refer directly to the section numbers in the report that resulted from the Training, Research, and Test Reactor (TRTR) organization review of Ford Nuclear Reactor operations, July 8 - 9, 1992. The recommendations are summarized here, followed by the action that will be taken by the Ford Nuclear Reactor facility.
Many of the recommendations have already been incorporated into facility operations and procedures. The recommendations that apply to the facility and that have not already been incorporated will be added in a deliberate, responsible, and safe manner.
4.6 Near Term Recommendations (1) Upgrade and preferably replace the existing intercom.
The overall facility intercom is satisfactory, but the intercom between the ccentrol room and the bridge will be upgraded or replaced to provide improved communications between the two locations.
(2) Install rod bottom indicator lights that are visible to those performing refuelings.
Mechanical rod position indicators are available to operators on the reactor bridge, but rod bottom indicator lights will provide more readily visible indication that-rods are fully inserted.
The design for rod bottom lights is in progress. The lights will be installed in a timely and responsible manner after design review.
7
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-Appendix 1 Reportable Occurrence 15 Corrective Actions September 14',_1992 (3) Adopt a policy of requiring two independent checks of the following:
(a) Verification of core _ position prior to removal / insertion of fuel.
(b) Verification of fuel element number.
(c) Verification that inserted elements are fully inserted.
Administrative Procedure 301 has been revised to include all of these recommendations. Core position verification is confirmed between the console operator and the fuel movement coordinator. Fuel element number and full insertion are verified by two individuals involved in the fuel movement..
(4) Be certain that someone is designated as the focal person for every significant operation including refueling.
For refueling, Administrative Procedure 301 requires a fuel movement coordinator separate from the crew members on shift. For the remaining procedures, separate focal persons will be designated, where appropriate, to coordinate and supervise completion of procedures.
(5) Inspect the fuel handling tool for mechanical integrity on a regular basis, perhaps annually. Check the fuel handling tool for operability prior to use.
There is neither indication of nor reason to suspect mechanical defects'in the fuel' handling tool, particularly since the eleven-pound weight of a fuel element places almost no stress on the tool. However, a maintenance procedure will be prepared for annual inspection of the-fuel handling tool. The procedure will include both a weight test-and a mechanical ~
integrity test.
The operability of the tool is tested before each use because the fuel element-bale gripper is normally closed and must be mechanically opened in order to latch onto an element.
(6) Attach a lanyard or float to both the key for fuel handling and its padlock.
This recommendation will be implemented.
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- l Appendix li
- Reportable Occurrence 15 Corrective? Actions-
' September 14,11992-
'( 7 ) Establish'a formal-limit--on.the height to which an- -
. element may be raised during refuelings.
A ' radiation : monitor on. the . reactor bridge prov' ides indication of increasing radiation-levels and it alarms'. '
at 40 mrem /hr.- It is felt that this is a better
" limiting" device than some sort of marking _on the fuel handling tool because radiation levels from fuel vary with time in core and decay time out of core, and an.
operator-may concentrate too strongly on a-tool-' marking when s/he should have a greater awareness of the overall evolution.
(8) Movements of fuel elements should be1 recorded in the c onsole log or,_ alternatively, the console operator should initial eachimove of the-fuel-handling: schedule as it is-done.
Administrative Procedure 301-has been modified to require the latter. In addition, commencement and completion of the procedure is logged in the reactor logbook to facilitate historical reconstruction of events.
(9) The training given on corrective action for the occurrence should be formally documented.and'all personnel should receive mock-up' training.
Each operator reviewed the fuel movement procedure;and-performed a simulated fuel-movement procedure prior-to actually performing the procedure. The procedure review.
and training has been documented.
Standard practice is-to route all1 procedure revisions to operators for review. The operators indicate that '
they have reviewed the procedure by initialing a p routing sheet.
(10) Require all licensed personnel-and those'in training to read a summary of criticality acci' dents.
A copy of NUCLEAR CRITICALITY. SAFETY by Ronald Kneif g
has been-obtained. -Appropriate sections will be-l-
provided to_all operations personnel for. review.-
Appropriate. sections o f the text will' be made part of the training program for new operators.
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Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992 4.7 Root Cause Analysis (1) Establish a chain of command and observe it. The chain should include a specification of an individual responsible for the conduct of each day's operation.
The facility has a clear chain of command. .The organization chart is in the technical specifications.
Each operating shift has a senior operator and an operator assigned to the shift who are responsible for the day's operation. In the past, during maintenance, even though a shift crew was assigned, the lines-of responsibility may have been unclear because of multiple maintenance tasks that were undertaken. In order to strengthen the organizational structure, two on-shift titles have been defined, and the titles will apply to both operation and maintenance. The Shift Supervisor is a licensed senior reactor operator on shift who has overall responsibility for the conduct of operations and maintenance. The Shift Operator is the licensed operator or qualified trainee on shift who reports'to the Shift Supervisor. One of these individuals will be signed in as console operator at all times. Shift relief for regular shift turnover at the end of shifts has been procedurally quite formal; in the middle of shifts it has been less formal.
Operating Procedure 103 has been revised to require formal turnover at any time the_ Shift Supervisor or Shift Operator is relieved so there will be no doubt who is responsible for shift evolutions.
(2) The individuals responsible for overall direction of the facility (Laboratory Manager and Assistant Managers) should not also perform duties of console operator during refuelings or other major operations.
Operating Procedure 103 has been revised to require that an individual with a specific interest in the success of an evolution will be neither the Shift Supervisor nor the Shift Operator during the performance of the evolution. This would preclude the-Assistant Reactor Manager from being the Shift Supervisor luring fuel movements when s/he has prepared the fuel movement schedule.
l l Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992 (3) Give the on-duty supervisor the authority and responsibility commensurate with the title. In particular, the Assistant Manager for Operations should limit the amount of time that he spends in the control room or its immediate vicinity.
The changes described in (1) and (2) above enhance the authority and responsibility of the shift operating crew, but the authority and responsibility were in place before reportable. occurrence happened. The senior operator on shift has-always had responsibility for reactor operation and safety. _Part of the job responsibility of the Assistant Manager for Operations is to review and supervise operation of the reactor.
It is unreasonable to expect him to not spend time in the reactor control room for both review of operations and training. However, every attempt will be made with the senior operators on shift (Shift Supervisors) to re-emphasize to them that they are completely in charge of shift operation and that deference to the Assistant Reactor Manager for Operations is not expected and could detract from the safe operation of the reactor.
(4) Assign those holding senior operator licenses the responsibility for preparing the fuel loading forms and the experiment authorization forms.
The Shift Supervisor will initially be informally assigned responsibility for both of these items on a trial basis. Should the trial work out, the applicable procedures may be appropriately changed. If the change is made, the Shift Supervisor will perform the initial preparation, but a final review and approval will be performnd by management.
(5) Allow some of the more senior SROs to attend meetings of the safety Committee.
For. future Safety Review Committee meetings, all members of the reactor operations staff will be given the opportunity to attend.
(6) Viable candidates-to replace the Assistant Manager for Operations at the time of his retirement need to be identified at once.
An informal search for external candidates is underway.
Internal candidates are also being considered.
l l Appendix 1 Reportable _ Occurrence 15 Corrective Actions September 14, 1992 S.! Refueling
- 1. See recommendations given in Section 4.6
- 2. It is suggested that personnel check themselves-for contamination upon completing refueling.
Radioactive contamination has not been a'significant problem with refueling.
A hand and foot counter has been-moved to the single stairway exit from the pool floor to make self monitoring more readily accessible. The background levels in the area may be too high to permit successful use of the instrument, but an evaluation is underway.
- 3. It is suggested that personnel read their pocket <
dosimeters upon completion of refueling.
Pocket dosimeters are required on.ly in high radiation areas at the Ford Nuclear Reactor. Radiation exposure-during refueling is negligible, and is not and has never been an-operational problem. /us was stated earlier, the bridge radiation monitor provides an indication of abnormal dose rates.
- 4. Step 6.10 of Administrative Procedure 301 directs the operator to tape the fission chamber positioning switch-to prevent movement of the fission chamber during fuel movement.
While_ placing tape over the switch has been effective, the requirement has been changed to-tag-out the switch.
The facility hasca tag-out procedure, Calibration and Maintenance Procedure 308. Currently, it applies only to failed equipment. It will be modified to include placing equipment out of operation.for maintenance, experiments, and reasons other than failure.
5.2 Conduct of Operations
- 1. A tag-out (and for electrical equipment, a lock-out)-
system should.be established.
Calibration and Maintenance Procedure 308-is a tag-out procedure with different types of tags for mechanical and electrical equipment.
y Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992
- 2. The console los should be a working document from which the chronology of events can be deduced. It is suggested that entries include shift turnovers, fuel element movements, completion of major procedures, sample insertions and removals, and equipment failures.
All of the suggestions except sample insertions and removals and equipment failures are now required entries based on revisions to Operating Procedure 103.
Equipment failures are recorded in a separate log.
Samp'es are also logged in a separate log. The Ford Nuclear Reactor performs so many irradiations that the reactor logbook would contain very little else except sample entries. The current system is more appropriate for this reactor.
- 3. A procedure in the form of a checklist should be written to address restarts from unanticipated shutdowns. It should include:
Nature of Shutdown Cause of Shutdown, if Determinable Corrective Action Taken Checks of any Repaired or Restarted Instruments Authorization for Restart Restart from unanticipated shutdown will be added to the facility procedures, either to an existing procedure or
- in the form of a new procedure. A checklist or a stamp for the reactor logbook will be put into use.
l 4. The facility has both normal and emergency procedures.
I However, there appear to be no abnormal procedures.
( An abnormal response procedure will be prepared. It will include operator responses to control console alarms and to appropriate events outside the control j room.
I 5. It is suggested that a formal program for surveillance of i reactor operation be established in which senior staff periodically checks cn the conduct of activities delegated j to the less senior staff.
l Operating and maintenance activities, as appropriate,
! are currently, formally reviewed with a signature or initial. The reactor logbook is reviewed regularly by the Assistant Manager for Operations. A program of surveillance of back shift and weekend activities has not been put into effect, but the Laboratory Director, the Reactor Manager, and the two Assistant Managers are often at the facility at odd hours.
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-Appendix 1 Reportable Occurrence 15 Corrective Actions September 14,1 1992
- 6. Conduct of operations in the control room should be more- -
formal including a standard shift turnover, a written policy on reading material, and limits on the number of people in the control room. Use of'the telephone should be examined.
All of these items will be given consideration. -Many of-the experiments and classes run by the facility involve significant numbers of students being in.and around the control room. 'Among its other functions, the facility is utilized-heavily for training. Rather than distracting from reactor operation, student participation enhances facility operation. . Operations
_ personnel are quite conscientious about not letting students in the control room distract them from reactor operation. The telephone does occasionally interrupt reactor evolutions. The_ operators are capable of answering the telephone, maintaining safe reactor operation, and safely completing procedures in progress.
- 7. Students who require access to the control room should be briefed on the importance of control-room discipline.
Current control room discipline is adequate, but a section will be_ inserted in the facility's Instructions to Workers that specifically addresses the importance of conduct involving reactor operation and, in-particular, conduct in the control room.
- 8. It is suggested that operations staff meetings be held on a regular basis.
This idea will be discussed with the reactor operators.
Because the-reactor. operates on a 24-hour-per-day rotating-shift basis, it is difficult to bring-the entire staff together at one time. All procedure changes, other changes in-facility documentation, NRC notices,_and information.of interest'to-reactor operators is routed to them for individual attentien and initially to indicate that they have received the information. There is currently a steady flow of formal and informal communications between management and the operating staff.
1 Appendix -- l -.
- Reportable Occurrence'15 Corrective. Actions-
. September;14, 1992
- 9. -It1is, suggested that a program be' established'for;the formal 1 review-of procedures.
o Procedure preparation and review at the Ford Nuclear--
Reactor is formal and thorough. . All~ procedures are given a-general review annually.; Complex procedures are reviewed before use. -Each revision is' documented with the revision number, and the revision number ~is placed in the right hand margin to' indicate:the specific-changes associated with each revision.- All procedure revisions are examined. tar manegement for safety related-significance. TheEsafety.relatedisystemsJare the.
reactor pool, the primary coolant system,"and the; reactor and facility instrumentation required'by.
technical specifications. All revisions are routed to every member of theLoperations staff.- Substantive changes are approved by the Safety Review Committee before a revised procedure is_. implemented.
Non-substantive _ changes canfbe-implemented before Safety '
Review Committee approval.
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y-l l Appendix'1 Reportable Occurrence-15 Corrective Actions September 14, 1992 5.3 core physics-Calculations
- 1. The present method of calculating shutdown margin is in conformance with technical specifications but it'does not address samples.
Operating procedure 105 provides the method for calculating shutdown margin. Currently, when removal of a secured experiment is planned in mid cycle, two shutdown margin calculations are done prior to commencement of the cycle, one with'the sample in place and one with the sample removed. The latter ensures that adequate shutdown margin will exist after the sample is removed.
The procedure will be altered so that an evaluation of shutdown margin at the beginning of a cycle is always done for the reactor with secured samples in place and with secured samples removed. If the shutdown margin is inadequate with secured samples removed, the samples will not be permitted to be removed in mid cycle until the reactor is shutdown and fuel elements are removed from the-core in sufficient number to meet minimum shutdown margin requirements.
- 2. Refueling expertise should be transferred to the less senior staff.
The less-senior staff will be trained in refueling plans and-techniques. Eventually, Shift Supervisors will perform the initial refueling plan, but'it will be reviewed and approved by the management before it is carried out. Shift-Supervisors will be expected to train Shift Operators na they complete the planning.
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i Appendix'1 ,
Reportable Occurrence 15 Corrective Actions-September 14, 1992
- 3. Shutdown margin calculations should be estimated prior to reactor startup or technical specifications should be altered to permit startup to verify shutdown margin.
Because the value of rod reactivities is limited, the reactor is operated very close to the technical specification shutdown margin limits. A calculated value of shutdown margin could not be trusted because even small variations in xenon, temperature,-and particularly fuel loading in the core could make the difference between meeting or exceeding technical specification limits.
A series of reactivity measurements was performed for fuel in different core locations. As expected, the reactivity per gram of fuel varied widely from location to location. But, even in the name location, reactivity per gram varicd for measurements performed at two dif ferent times because of the dif ferences in surrounding fuel element burnups.
Shutdown margin must be confirmed by measurement. An amendment to the facility technical specifications will be requested that requires minimum shutdown margins for routine operation, but permits startups to measure the value.
- 4. It is suggested that a reactivity comparison be.made between a depleted and a fresh-shim-safety rod.
The reactivity comparison of a new and a depleted shim-safety rod can be made historically. The current rods are not the original core rods. The current rods were installed in the early'1970s. A historical comparison of-rod worths was done for comparable surrounding fuel element loadings. The total worth of the three shim-safety rods In 1975 was approximately 7
% Delta K/K; in 1992 the total rod worth was approximately 6.5 % Delta K/K. The-decrease in rod worth is partially due to boron depletion, but it also decreased because typical reactor cores are larger today than in 1975 and the flux in the rod locations is somewhat lower.
n 7 l l' App'endix_1-Reportable _0ccurrence 15 Corrective Actions =
-September'14,x1992
..t$.
5.4- Reactor Startups 1.- It is suggested that-an estimated critical position;be-determined prior: to each startup.= ;
A precise critical rod height is .r.. i significant:
operational-importance to.the facili . The critical rod heights are carefully measured at the.beginning of- "
each cycle to evaluate er. cess reactivity and shutdown margin. These values can-be compared with the' previous cycle to lookLfor apparent anomalies:since the initial critical rod heights at the beginning of-a cycle must be nearly the same to satisfy-excess reactivity and ,
shutdown margin requirements. Thia comparison?could be of some value, for example, if one of the: rod magnets did not latch and the startup were done with two '
shim-safety rods rather than three.
Operating procedure 101, Reactor Startup, has a Cycle Operating Schedule. An acceptable range for critical rod heights at the beginning of~a cycle will be added to the schedule.-
- 2. It is suggested-that the completion of checklists that support a startup be recorded in the console log.
Operating procedure 103 has been revised 7toLrequire-recording commencement and completion of. procedures in the reactor logbook._ The startup procedure will be-specifically-altered'to require that completion of si rtup checklists be 2ecorded even though-that is ,
currently done.
Should fission chamber movement during.startup be recorded
~
3.
in the reactor logbook?
^
E The fission chambers provide a; relative indication of-L reactor power. Their real value 'isito indicate rate of.
change of power at low power levels.- Fission chamber.
i position-is not of operational significance and need-not L be recorded, i.
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Appendix 1 Reportable Occurrence 15 Corrective-Actions September 14, 1992
- 4. It is recommended that the startup steps be put in the form of a checklist with each step being initialed to avoid confusion should there be a shift change at some point during a startup.
The prestartup checks are in the form of a checklist A 3 that the operators initial as each step is completed. j startup stamp is entered in the reactor logbook for each l startup. The major steps in the startup are recorded; fission chamber counts with rods on the bottom,-fission chamber counts at shim range to ensure the renotor is )
still subcritical, neutron channel-indications at 500 kw, and rod positions when full power is reached. A' ;
startup requires about 15 minutes. The procedure would not be interrupted for shift turnover. To have a l checklist that an operator had to initial at each step such as fission chamber adjustments and range changes on the linear level would detract from the evolution rather than enhance it.
5.5 Experiment Review
- 1. It is suggested that an estimate be made of the reactivity worth of each sample prior to its insertion in the core.
Any experiment that is significantly different from those previously performed or whose reactivity is estimated to be greater than 0.0012 Delta-K/K (movable limit) must be reviewed and approved by the Safety Review Committee.
If the experiment is evaluated as secured, it is loaded while the reactor is shutdown and its reactivity is measured as the difference in core reactivity with the sample inserted and with the sample withdrawn.
Any sample covered by a reactor utilization-request routinely' released to the control room has been
. evaluated as movable. Even so, for the initial loading of the sample a careful reactivity evaluation is made by-balancing control rod motion against sample insertion.
If the sample approaches the movable limit, it is carefully withdrawn and management is notified.
Iloweve r , a technical specification revision will be considered that would stipulate that the secured and movabic classifications apply for routine irradiations, not for reactivity evaluations.
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Appendix 1 Reportable Occurrence 15 Corrective Actions' September 14, 1992
- 2. The dose at a specified distance should be estimated for each sample and the information should be made available to the person who will be removing the sample from the
~
pool.
Operating procedure 104, Reactor Experiments, describes-sample handling. Rather than relying on estimates o-calculations, sample radiation dose rates are determined by measurement. An operator may raise a sample-out of the pool water or from-its container to check its radiation level. If the level exceeds one ren/hr at one meter, the sample must be returned to the pool or to its container. Below that-level, it can be transferred to temporary underwater storage to await decay. A health physics staff member must be present to transfer samples out of the pool. In the absence of a health physics staff member, reactor management may act for the health physicist and release samples under specific conditions.
Dose rates are measured and activity estimates based on dose rate and isotopo content are made at that time.
i
- 3. Individuals who will remove samples from the pool should be alerted to any that have high energy beta radiation.
Operations personnel are required to wear eye protection when handling samples. Tools are provided to allow a standoff distance when handling samples.
l l
L 4. The reactor utilization requests should include a provision for checking alpha heating.
Management procedure 401, Experiment Review, provides the requirements for initial evaluation of all experiments. Heating and surface temperature are items that are considered in the initial evaluation.
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P Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992
- 5. It is suggested that a specific sample tracking form be prepared in addition to the reactor utilization request to track composition, nuclides, dose, reactivity, and any special hazards.
Each reactor utilization request corresponds to a unique sample or experiment. If items related to the utilization request change, such as sample composition, expected nuclides, or the name of the experimenter, the utilization request must be modified by management or a new request must be prepared.
An irradiation history tag is prepared for each sample or set of samples that is irradiated. The tag serves the purpose of the sample tracking sheet. It is kept with the sample and is released with the sample to the experimenter.
- 6. It is suggested that a utilization plan be given to each experimenter.
Each experimenter is given basic health physics instructions when s/he comes to work at the facility.
The experimenter completes all the technical data on the reactor utilization request. If the experimenter actually performs the experiment, as opposed to laboratory personnel, s/he is trained on specific procedures by the health physicist and the health physicist observes the first performance of the experiment. The reactor utilization requests are distributed to the control room, the experimenter, the health physicist, and the Reactor Manager.
Unique experiments are reviewed by the Safety Review Committee. Any special evolutions, such as chemical processing of radioactive materials and irradiations at high temperatures and pressures, must be submitted with-the experiment description and must be approved by the committee.
5.6 Health physics
- 1. The use of a hand and foot counter should be mandatory for all personnel leaving the pool floor.
A hand and foot monitor has been moved to the single stair egress from the pool floor; the second set of exit stairs has been removed. It will be evaluated to see how sensitive it will be based on the higher than normal background levels of radiation in the pool floor area.
l Appendix'l Reportable Occurrence 15 Corrective Actions September 14, 1992
- 2. It is suggested that all exit routes from the reactor be equipped with a device for checking contamination.
Each floor of the facility has a hand and foot counter with a separate pancake-type frisker. The main loading dock exit from the building has a portal monitor that covers both the loading dock door and the personnel access door. Radioactive materials are not normally taken through the remaining four access doors, with the exception of planned shipments, in which case the packages are transferred through the front lobby door.
- 3. It is recommended that the eating / smoking area adjacent to the control room and near the pool floor be moved.
Operators can eat in the control room and in the classroom opposite the control room as well as in the designated area adjacent to the control room. This area is the only designated smoking area in the entire facility. It was purposely selected because it is near the control room so that operators do not have to go to some remote area or outside the building to smoke. -In addition, the ventilation air flow rate is high in the area and the air flow is away from the area toward the pool floor and into a ventilation exhaust plenum on the pool floor.
- 4. It is suggested that regular meetings be held between operations and health physics managers.
Communications between the two occur on an almost daily basis. At any time a specific need arises, meetings are held.
- 5. It is suggested that a method be established to ensure health physics review to changes in procedures if those procedures involve health physics considerations.
Facility health physics procedures are maintained and revised by the health physicist. Facility management is responsible for ensuring that a health physics review is conducted of operating procedures that have health physics implications. A specific method involving another procedure is not necessary.
- 6. The use of Masslin cloth or mops is suggested as a more efficient means of taking smear surveys.
The current smear technique is standard for the industry and is effective. Surface contamination is detected where present. The facility does not permit any standing contamination in general access areas. !
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l Appendix 1 l Reportable occurrence 15 Corrective Actions September 14, 1392
- 7. It is suggested that a formal mechanism be established to ensure the timely performance of any technical specification tests that are the responsibility of the health physics organization.
Health Physics Procedure 219, Health Physics Duties Schedule,-has recently been prepared and delineates the monthly, quarterly, semi-annual, and annual calibrations and tests required to be done by the Health Physicist.
Should any of the requirements approach the frequency interval limit, the Health Physicist is required to notify the Reactor Manager and the Radiation Safety Officer.
- 8. Initiate an ALARA program.
A University-wide ALARA program is in place.
A formal, procedural ALARA program at the reactor does not exist, but ALARA is considered in the design and operation of all equipment. For example, over the past few years, the number of sample irradiations has increased by a factor of more than ten. Radiation doses from sample handling, the major source of reactor operator radiation exposure, have gone up by less than a factor of two. This was due to the thought given to design and use of sample irradiation holders and equipment. At present, a further ALARA study is underway using film badges to evaluate major sources of radiation exposure related to the various operator work tasks.
The use of disposable ion exchange resins -at a cost to the facility of about $30,000 per year- and the elimination heavy water transfers were motivated by ALARA principles.
A major redesign of the shim-safety rod magnet system is in progress to-provide above surface magnets rather than underwater magnets. The redesign is intended to improve reactor reliability, but it will have a significant ALARA impact because the need to remove radioactive magnets for inspection and repair will no longer be necessary, t
e g ,, .
4 js *:
ft-Appendix 1-Reportable' Occurrence.15_ Corrective Actions September- 14,_1992.
It=-is recommended that_ performance of maintenance on the-
~
9.
back shifts be reviewed in the context'of ALARA..
Specific guidelines are provided-for maintenance-on-the
.back shifts. Radiation dose rate limitn'are placed on detectors, rod-magnets, and sample l holders fcr. removal-of'these items'from the reactor pool-for_ maintenance.
If the limits-are exceeded, the-devices cannot be ._
- removed from the pool or a member of the-health physics staff must be present during their removal. -!
Management Oversight j 5.7
- 1. Identified areas of weakness in the Safety Review-Committee are:
(a) The committee lacks an audit. function; (b) The committee membership does not include people withL ,
experience in reactor. operations; d (c) The committee membership does not include people who are not emplo:r.3 by the University of Michigan; (d) Attendance at meetings is limited'to the. reactor's senior staff.
The' audit function in technical specifications is.
performed by an outside auditor, preliminary inquiries have been made to the Reactor Manager-of-the Dow-Chemical Company reactor to.be a member'of the Safety. !
Review Committee-and tofaudit the reactor on a~ mutual -j exchange basis. .-Mutual audits are currently cross-conducted with-the Rhode Island Nuclear Science Center and the University of Lowell Reactor.
In the future, the Heal'th physicist and. reactor-operations personnel'willibe-given the opportunity to attend-Safety Review' Committee meetings.
1
- 2. It is suggested that there be: regular,- formal'. meetings of i the senior management.
Meetings-are held on an as-needed-basis. With a small-
. facility,_ regularly scheduled meetings.are'not needed because management has every day contact and communication.
Appendix 1 Reportable Occurrence 15 Corrective Actions September 14, 1992
- 3. Having a set of management procedures that do not involve reactor operators is self defeating.
Reactor operations personnel wil1 be more involved in
" management" type procedures such as experiment reviews, fuel' inventories, fuel shipment preparations, and core loadings in the future.
- 4. Manpower needs should be reviewed.
The facility has planned thoroughly for operator manning needs. Six operators cover the three shifts. Two operators serve as suxiliary operators for special tasks and to fill in as needed on shift.- Two more senior operators run the machine and electronic shops and 1 perform shift relief duties as needed. The three managers, the technician who performs neutron activation.
analysis, and the research-associate who' directs the nuclear medicine unit are licensed and perform regular shift-duties. Two 20-hour-per-week trainees are in training to replace the next two operators who resign from the facility.
Selection and training of a replacement for the Assistant Manager for Operations, who retires in the summer of 1993, will begin as soon as a qualified I
external or internal candidate can be found. There are
- individuals currently on the staff who, while they lack experience, with proper training could adequately fill any of the management positions.
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.t Appendix 1 Reportable Occurrence 15 Corrective Actions September. 14, 1992
- 5. Management should foster a climate or culture in which safety is uppermost.
Any implication that reactor safety is not uppermost in the eyes of management and the rest of the reactor operating stat'f is false. The facility has a comprehensive training program. Areas such as reactor theory and radiation protection are covered to a depth greater than that required for reactor operation because management has always believed that depth of knowledge-enhances an operator's ability to safely operate the reactor. Detailed procedures.for every evolution have been prepared and frequent reviews and revisions are made. Every evolution is carefully thought out and simulated before it is put into' procedural-form. Input is obtained from all applicable personnel.
Facility management and staff recognize that safe operation of the . reactor has a broad _ impact on the nuclear industry. Students at the University of Michigan, many of whom participate in reactor laboratories and experimental work. will be the next generation of engineers and managers in the nuclear industry.
- 6. See Section 4.7.
- 7. See Section 5.5.6.
- 8. See Section 5.2.5.