ML20043H437
| ML20043H437 | |
| Person / Time | |
|---|---|
| Site: | 05000054, 07000687 |
| Issue date: | 01/09/1987 |
| From: | Mcgovern J CINTICHEM, INC. |
| To: | Wenzinger E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20043H402 | List: |
| References | |
| FOIA-90-97 NUDOCS 9006250405 | |
| Download: ML20043H437 (8) | |
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r CINTICHEM, INC.
a whoDy owned subsidier y of Medi-Physics, Inc.
r>.a. sox e,s. Tuxeoo. NEW YORK 10987 1914) 351 2131 t
Jantary 9,1987 Mr. Edward C. Wenzinger, Chlef Projects Branch No. 3 Divison of Reactor Projects U. S. Nuclear Regulatory Ccrnmission 631 Park Avenue King of Prussle, PA 19406 Ocar Mr. Wenzinger:
1 The following is submitted in response to your 50-54/66-02 and 70-687/86-03 Inspection report.
The response is organized to correspond to p
the headings used in the November 25, 1986 report.
Due to delays in Cintichem's receipt of this NRC report and in staff absences during the
.hol i day s, Clntichem requested an extension of the thir+y day response requirement.
Per a Decmber 22nd telecon with Mr.
T. C.
Elsasser of your staf f, a f if teen day extension was granted.
i REACTOR BUlLDlNG CONTAlNENT l
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Summary of Event The October 1984 event involved commencing a reactor startup and bringing the reactor to a power level of.005% of full power (250 watts) with the outer upper level peele door not completely closed while its adjolning door was l
open.
The time period of this situation was approximately 15 minutes before the door gasket was inflated.
The Senior Reactor Operator perf orming the reactor startup was eware of the status of the outer upper level peele door.
He -commenced the stariup because he felt he had met the Technical Speci f ication confinement requirements.
His specif ic assessments f or this dectslon were:
1.
The reactor building was in a negative pressure condiflon prior to and during the startup.
2.
The outer upper level peele door could be f ully contained within one or two minutes.
3.
He knew of no provlslon in the Technical Specifications requiring door gasket inflation.
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He Intentionally planned to limit the roactor pcmer to 250 watts until the non-normal ventilation situation was corrected.
(This 250 watt level is the normal level where the reactor pcwer increase is stopped to measure control rod reactivities.)
initial CIntichem Review The Manager of Nuclear Operations, the Reactor Supervisor, and the Chlef Reactor Operator revi ewed this startup f ol lowing the event.
The determinati on, at that time, was that this was a non-normal startup but that it was not a Technical Specification confinement violation.
it was viewed as falling into a Technical Specification Interpretettonal aron that did not speelfically violate confincrnent requirements.
This determination was made because of the reasons presented above and because of how we perceive our nonnel confinement requirements in regard to opening and closing gasketed doors.
Specifically, our present contalnment sy stem utilizes two sets of personnel door s.
Each set has one door not equipped wIth an inflatable ga ske t.
Personnel, in norm 6i practice, continually enter and exit the confinement building and Inflate and deflaie the one inflatable gasket.
For 13 of the 25 years of reactor operation at Sterling Forest those personnel door pairs did not have inflatable gaskets on either door.
During this 15 minute event, the reactor building was held at approximately.25 inches i
nega tive.
The Technical S peci f I ca tion s, though, do not require a building negative pressure to be maintained during normal operation.
The Technical Specifications only require us to be able to maintain.01 inches negative l
during an emergency condiflon where the emergency f an and fliter systems are In operation.
Thi s requirement is checked semi-annually where we perf orm a l
1est in which we maintain the negative pressure f or twenty minutes.
This test Is perf ormed with the doors maintained shut because continued entry and exit l
f rom the building would jeopardize maintaining the negative pressures.
This says that in an emergency the operators must shut and maintain the doors shut.
In the subject October 1984 Incident, the door could have been quickly contained, within no more than one or two minutes, thereby establishing and maintaining the required containment.
This Is simller to the normal situation where a gasketed personnel coor is opened f or building entry.
This door would have to be manually shut and its-gasket inflated to maintain containment in an emergency.
The time periods involved in both concitions are similar.
1986 Clntichem Review l
Following the August 1986 NRC Inspection, we again reviewed this event, i
We still feel a valid case can be made that this was not a Technical Speelfication confinement violation.
However, even If we were to persuade the NRC of the correctness of this position, we would not want to operate our containment in this mode.
The f ollowing corrective actions have theref ore been taken.
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Corrective Actions 1.
This event has been discussed wlih alI reactor operator s.
It was specified that the reactor should not be started unless one door of the double peele doors was closed and gasket inflated.
Furthermore, if future operator questions should arise concerning non-normal containment condiflons prior to a siartup, the startup should not commence without specific approval of the Reactor Supervisor e Level ll Management.
e mdures manual form has been instituted to allow operators to, 2.
A new.i Dr ing up questlons of Interpretation. Thl s f orm w ll l be used as r
f ormal l a vehicle to insure questions are f ully discussed and that feedback is provided.
l Cl.EANING OF REACTOR HEAT EXOlANGER NO POOL WALLS Summary of Event Clntichem has algae in its primary water system which requires periodic cicening.
The accumulation of algae in the heat exchanger is reduced with a H022 cleaning to maintain the design flow rate and mean temperature difference.
This heat exchanger cleaning has been done on an annual frequency.
Spray washing the pool walls is also done periodically to control pool wall-algae growth.
4 The last heat exchanger cleaning occurred on March 6,1986. On that date both heat exchanger bundles were cleaned and the pool-and stall walls were spray washed.
The heat exchanger cleaning procedure basically calls f or isolating the heat exchanger by closing valves and then circulating H 02 2
through both bundles.
The H 02 2 breaks up the algae which is then flushed to the sumps with clean pool water.
Most of the algae is thus broken lose and flushed into our radioactive waste water system.
The pool and stall walls are cleaned by a high pressure water spray gun which breaks the algae lose frcm the walIs.
The-Ioosened algae particuiate Is then deposited in the primary water system and is filtered out through our demineralizer system filters.
The March 6th cleaning of the heat exchanger produced better than usual cleaning results in that the primary coolant flow was re-established at the high end of its operating band.
The pool well cleaning also produced good cleaning results.
The other result f ollowing this dual cleaning ef f ort was that the pool water now contained quantitles of fine algae particulate.
This particulate matter reduced the clarity of the pool water to the extent that normal core visibility was obscured.
The pool surf ace is approximotely 25 feet above the reactor core.
Unless the pool water is extremely pure, visibility will be obscured through this amount of water.
Past peroxide cleanings had caused water cloudiness.
The March 1986 cleaning, because of the good cleaning results and the concurrent cleaning of the heat exchanger and pool wal l s, resulted in more cloudiness than what had normally been experienced in past cleaning operations, o
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4 Following these cleantng procedures, preparations were made to resume reactor operation.
The normal prestart checks were done and were marked with 1
a notation that the water was cloudy.
Prior to the startup, and with the water lowered to the stall shel f, a Senior Reactor Operator inspected the core.
The core top was seen to be clean and f ree f rm flow blockage and with this and other startup check Inf ormation the Senior Operator approved the startup.
The reactor was then started on the mid-night shif t of Friday, March 7th.
The-startup and subsequent opera tion was n orma l.
All site supervisory / management personnel responsible for reactor operations were aware of the unusually poor pool water clarity.
These included the Plant Mcnager, Site Operations Manager, 2 nager of Nuclear Operations, React or Superv i sor, and the Chief Reactor Operator.
The situation was assessed and discussed and reactor operation was continued.
In the event of an unscheduled occurrence which required core work, a contingency plan was f ormulated to shut down the reactor and to do any such work with the water level lowered to the shel f where visibility was acceptable.
Tmporary auxillery f litering units were placed in service to more quickly restore water clarity.
The reactor was then operated normally through Friday, Saturday, and Sunday. On Sunday at noon the first isotope production target removal was perf ormed.
The Senior Reactor Operator on shif t discussed this target removal with the Manager of Nuclear Operations via telephone on Sunday prior to the removal operati on.
By th i s time on Sunday, with the maximum demineralizer system flow through the domineralizer f liters and with the extra help of the tmporary particulate f liter system the water clarity had improved.
The core was visible end target stringer posi ti ons could be identified.
The water clarity thereafter continued to improve to normal.
The Sunday target reoval procedures occurred as previously scheduled during the previous week.
-The ta cving week a group of operators expressed concerns about the water clJdor.s in a memo written to management.
This memo, dated Friday, March li'n, was not wen by supervisors / management until Manday, March 17th.
This tM ; dif fe om the understanding the (IRC has of this incident as discussN '. ths wber 25th report.
The mmo stated that "although the areas ot.nre w nassed with the subsequent clearing of the pool water" certair we4 c+
still needed management / operator discussion and r
explana M.
/ w a "ran the Reactor Supervisor, issued March 20th, discussed in detar t! r arce where operators had expressed concerns.
Meetings were then scheuuieo e,iu held that week with all management and operators to f ully discuss the cloudy water situation and management's reasoning behind the dect slons that were made during the period of low water visibility.
Justification f or Operation At the time of this event, management and supervisory personnel discussed and analyzed this situation and concluded reactor operation was saf e with water clarity reduced.
The f ollowing assessments were made in arriving at this declslon.
1.
Prior to the reactor startup, the reactor core was viewed f rm the core shel f to be clean and free of any Indications of flow blockage.
All normal prestart checks were perf ormed sati sf actor ily and all reactor instrumentation and control s responded normally to the checks and the subsequent startup and reactor operation.
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The reduced vi sibil ity was due to the break up of al gae into fine particulate.
The particulates produced a turbidity which obscured core viewing through 25 feet of water.
It was judged that the fine algae particulate would not cause flow blockage.
3.
If core blockage shoulo occur, even though the algae partiuclate was judgM to have not caused a signif Icent increase of this risk, it would bo sMcc%L Ossed on operating experience at this and other f acilities, H nos known that blockage of any significant extent would cause In-core nuclea% bolling.
TMs belling or vold formation would be seen quickly on tne nuclear Instrun.ddlon as oscillation or increased "nolse" on the Log N channel.
Operating eyelence with MTR cores has shown that more extreme bolling will cause en autmatic shutdown.
4.
No procedural or technical speci f ication criterla was violated by operating the reactor in this condition.
The technical speci f ications on pool water quality are primarily based on prevention of corrosion.
The parameters of pH and conductivity were within limits.
5.
During normal operation with good water clarity the core is not continuousiy viewed f or the purpose of checking f or fIow blockage.
F1cw restriction s can only be observed from directly above the cor e.
Binoculars have to be used f or any cl ose exam inati on of fuel pl ate A
channel blockage.
In normal operation this is not purposely done.
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fact, extended periods.go by in routine operation where the core i s not vlowed frm above.
Many non power reactors and all power reactors do not have the capability to visually monitor for core restrictions.
The primary and initial Indication of coolant flow reduction in our reactor and others Is by monitoring Instruments (nuctcar and auxii1ary) In the reactor control room, e
6.
As prev iously stated, Cintichem management and superv isory personnel L
Judged the risk of flow blockage to be low and reviewed the measured core - parameters which would Indicate the start of bolling should f l ow i
blockage occur. - Management knew that the margin to nucleate bolling was large and that the initiation of nucleate bolling was not in itsel f an
-unsafe condition.
The nucleate bolling region enhances heat transfer because _of the heat of vaporization required to cause the f ormation of bubbles and the treakup of the stagnate plate surface laminar water layer.
This nucl eate bolling region woul d have been detected on instrumentation and this region provides a large margin before you enter the steam blanketing region.
Following this event, this rationale was quantitatively reviewed with all operations personnel.
Using the Cobra lY C cmputer code, flow blockage conditions were examined in detall using dif ferent degrees of blockage.
The code was run with the conservative input assumptions of 130*F pool water, 2000 gpm core flow, and studied the hot channel which applies the maximum flux peaking f actor.
Actual Parameters during the event were pool water at 100'F and core flow at >2400 gpm.
The 2,000 gpm total core flow was ratloed down to the flow going through one et ernent.
This flow was then reduced down in the code studies.
This code predicted that nucloate bolling would cmmence at around 50% flow blockage.
It further predicted that at 90% flow blockage the exit core temperature was only
., 235'F.
Achievement of 955 blockage was necessary to reach burnout conditions at the hot spot In the hot channel.
These numbers, using the con servative input parameters, conf I nned our knowl edge that the fine algae particulate was not at all likely to cause the kind of massive blockage needed f or plate damage.
In addition to this Cobra Code review, two other reports, concerning f low blockage at other f acilities were reviewed with all operations personnel.
Summaries of these reports f ollow.
A.
Sims/ Tabor-Dak Ridge National Laboratory Report titled " Report on Fuel Plate Melting at the Oak Ridge Research Reactor".
This Incident report di scussed the results of a neoprene gasket causing f ull flow blockage to a f uel element.
The report notes that it appeared that the Log N period Indicated bolling at a power level of 9 MI and that it took an increase in power by a f actor of 2.7 af ter boliIng was observed bef ore plate damage occurred.
B.
Coimb/Binf ord-Oak Ridge National Laboratory Report titled "The Detection of Bolling in a Water Cooled Nuclear Reactor".
This report described their study of the measurable changes in the reactor power spectral den si ty produced by bubble f ormation.
It concluded that standard nuclear Instrumentation can be used as a method of detecting bolling.
Upcmina Plans We will have to continue our periodic cleaning of the heat exchanger and pool wall s.
The past procedure has been reviewed and a new procedure written.
It is presently under review and prior to the next heat exchanger cleaning it will have been apprcued by the Nuclear Safeguards Cmmittee.
This new procedure wlll het p minimize water eloudiness f of Iowing a clennup.
Al so, the
%rch 1986 practice of performing pool wall spraying concurrent with the heat exchanger cleaning will not be done in the f uture.
This double action was a contributing reason f or the extent of the March 1986 cloudiness.
Cintichem management is concerned with the apparent lack of cmmunications of operator concerns during the early stages of this event.
Measures to imprcue communications have been instituted through weekly scheduled meetings to discuss scheduled work and to critique current operating experience.
Additionally, a new procedure will be added to the Operations Procedures Manual.
The procedure will provide a f orm to be used by anyone to inttiate discussion and revlew of any piant practice.
ThIs wIII provide an of ficial f ormat to allow identification of concerns on non-normal operational conditions and will require supervisory / management review and f eedback.
This wlll f ormalIze discussion and feedback of any f uture operator concerns.
Conclusion Clntichem agrees with the NRC's f irst paragraph findings on this event.
Speci f ical ly the NRC's stat ment that "the LNRC] In spector reviewed the Technical Specifications f or pool water quality and reactor operation
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7 procedures and determined that there were no violations or direct adverse safety concerns as a result of thi s occurrence".
Cln tichem, though, also agoes that better and more f ormal operator / management communications would have relieved early operator concerns.
To facilitate better future ccrnmun i cations, the operations review
- form, discussed above, will be impl emented.
Also, when the reactor plant devlafes frcrn routine operations, management / supervision will write up temporary procedural changes or " night orders" to inf orm operators more f ully vf management operational assessments and decisions.
UNAUTHORIZED ACEESS TO THE CONTHOLLED AREA i
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. The August 7th Incident described in the NRC report involved tmporary student summer help.
These temporary employees were hired f or the summer as painters.
They were occupied in painting both inside and out side of all buildings on site.
To f acilitate this work, these people were screened per our security plan and were authorized to have access to the controlled areas.
In addition to the formal screening process, these people were personnally kncwn and two of the three were sons of existing empl oyees.
They were l
Indoctrinated on the reasons f or our security but, being temporary employees, I
were not fully aware of the consequences of giving access Information to l
representatives of the NRC who they recognized as such f rcm their presence on site the previous day.
j Overall, we believe that our security program is f unctioning up to the requirements of our plan and - that if plan infractions are noted, action is taken.
This is supported by the July 21, 1986 memo written by the Designated Controlled Area Security Of ficer to all Site Department Heads.
In this memo our security requirments were reviewed and the cooperation of all personnel In meeting the plan's objectives was solicited.
This action was taken to improve security f ol low ing concerns brought to management's attention by access area mployees.
The memo was not written to meet past or anticipated f uture NRC Inspector concerns.
L Corrective Action 1.
Access area door signs were changed last stsnmer to again remind all personnel of our security requirements.
2.
We have supplemented the training personnel will receive bef ore they are L
given authorized eccess.
The final check, af ter all other screening and security training has been accomplished, will be an Interview with the Designated Controlled Area Security Of ficer.
This interview will stress the importance of full ccmpliance to the plan and be a final confirmation that the mployoo understands the plan and conmits to its requirments.
3.
Authorized access I nf ormation will only be di ssem inated to permanent sployees who need to routinely enter the protected areas.
a OPERATOR REQUALIFICATION EXAMINATION i
Clntichem Reactor Operator s follow our NRC approved Operator Requa l i f ication Progr am.
Th i s program, as written and' administrated, meets the requirements as specified in 10 CFR 55 Appendix A 'Requal l f i ca tion Progr ams f or Licensed Operators' and ANSI 15.4 " Selection and Tralning of Personnel for Reseatrch Reactors".
10 CFR 55 Appendix A Item 7 also states that part 55 is applicable to research reactors in general but that it can be adjusted. to acemmodate the special modes of operation of non pcwer reactors.
-Of note here Is that our approved requal I f Ication plan states that the blennial written examination can be administered over a two week period and given in parts to meet the problems associated with the proper staf fing of the reactor when in operation.
These words were included in our plan to allow our small staf f to meet the requirements of administerin0 en exam in a f acility that runs seven days a week, 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day.
The exam has always been en honor systm non-proctored exam to accommodate our shift personnel.
One proctored exam period can not be achleved because of the various people on various shif ts and the f act that some personnel are always required to be on the ' job operating the reactor.
Cintichem has not seen any specific NRC
-guidance on this subject of proctoring requa l i f icati on program exems and believed our past practice was acceptable.
We also wish to state that the anonymous Individual who brought up this concern stated that in the most recent examination no operator received a i
grade lower than 89.
This statement i s not correct.
An operator's score is not published and is of ficially known only between site supervisory / management staf f and each operator.
Sme operators do discuss exam scores but this is on a one to one basis.
The " anonymous caller" apparently may have solicited exam scores f rm a f ew operators and f ound no score.in this smal I survey under 89.
The actual f acts are that 30% of the operef or s scored below 895 and. one operator-because of his test scores was put on a training upgrade program.
This program consisted of setf study of assigned material, pre-planned i
lectures, and a re-examination program consisting of f our examinations.
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This letter transmits our response to your Inspection.
Should the NRC require additional Inf ormation on any of these Itms, please contact me.
Sincerely,
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cM N ames. McGovern Plant % nager WGR: mag Attachments
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Docket No. 50-54 Union Carbide Corporation A1TN: Mr. James J. McGovern Production Manager, Radiochemicals P. O. Box 324 Tuxedo, New York 10987 Gentlemen:
Subject:
Inspection No. 50-E4/80-02 This refers to the inspection conducted by Miss Lisa M. McKeown of this office on' April 14-17, 1980, of activities authorized by NRC License No R-81 and to the discussions of our findings held by Miss McKeown with Mr. M. Voth and members of your staff at the conclusion of the inspection.
Areas examined during this inspection are described in the Office of Inspection and Enforcement Inspection Report which is enclosed with this letter. Within these areas, the inspection consisted of selective examinations of procedures and representative records, interviews with personnel, and observations by the inspector.
Our inspector also reviewed the steps you have taken to correct the item of
- noncompliance brought to your attention in a letter dated November 2,1979.
With regard to this previous item of noncompliance resolution of this matter is held in abeyance pending review and detennination by the Office Nuclear Material Safety and Safeguards.
Within the scope of this inspection, no items of noncompliance were observed.
In accordance with Section 2.790(d) of the NRC's " Rules of Practice," Part 2, Title 10, Code of Federal Regulations, documentation of your control and account-ing procedures for safeguarding special nuclear materials and your facility security procedures are exempt from disclosure; therefore, the enclosed inspec-tion report will not be placed-in the Public Document Room and will receive limited distribution.
No reply to this letter is required; however, should you have any questions concerning this inspection, we will be pleased to discuss them with you.
Sincerely, n c 0 3 ce lhtheFec 4
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Walter G. Martin, Chief Safeguards Branch
Enclosure:
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Unfon Carbide Corporation 2
16 WAY 1980 l
Enclosure:
Office of Inspection and Enforcement Inspection gportNo._50-54/80-02,
= w vn6ains co nutui un unne w i vu )
cc: with re$h, Manager Nuclearrt cover sheet only Mr.
. H. Vo perations W. G. Ruzicka, Reactor Project Engineer C. Konnerth, Health Physicist R. Bollinger, Vice President, Medical Products Division bec:
IE Mail & Files (For Appropriate Distribution) (w cy of encl)
Central Files (w cy of enc 1)
Public Document Room (PDR) (w report cover sheet only)
Nuclear Safety Infonnation Center Technical Infonnation Center (TIC)(NSIC) (w report cover sheet only)
(w report cover sheet only)
REG:I Reading Rocm (w report cover sheet only)
State of How York (w report cover sheet only) l l
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