ML20037B578
| ML20037B578 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/18/1974 |
| From: | Oconnor P US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20037B579 | List: |
| References | |
| NUDOCS 8010210866 | |
| Download: ML20037B578 (9) | |
Text
{{#Wiki_filter:^ ~ \\ r M
- bf
- k..~.' ~
kN y .,~
==& DEC 181974 W=E=~ ~~~ Docom .;.=. OPS 7. ten ...:== kl: ::
- p.. 5.
183s = c== [g;; ~ Docket No. 50 10 ~ N::::.::.3 }.. .. E.E. LICENSEE: COMMONWEALTE EDISON COMPANY .. Ex E ~"9EEJ FACILITY: DRESDEN NUCLEAR POWER STATION UNIT 1
SUMMARY
OF MEETING HELD ON NOVEMBER 26, 1974 TO DISCUSS DRESDEN UNIT 1 ...f DECONTAMINATION = ...r.. On November 26, 1974 representatives of the Conanoturcalth Ediaori Company . _,j.3 met with f:he Regulatory staff to provide a pre 24=inary sectus report on sw.s Connonwealth's proposed chemical decontamination of the interior surfaces
- j]Es i
of the Dresden Unit 1 primary coolant system. A list of meeting attendees "~:-::s is attached. .:= =- The purpose of the decontamination program is to remove a deposition of ..,;55fj activated corrosion products which is tightly bonded to the primary coolant ~!fff:T i system piping and components. The presence of the corrosion products .l;.;. in the system results in high levels of radiation in adjacent areas and 1 limits access to these areas for the purpose of in-service inspection, i routine maintenance, and plant modifications. Significant pointa discussed in the meeting are summarized below: 1. Strmary of the Dresden 1 Cleaning Project - W. P. Uorden - Commo: wealth ..l.; Edison Co:rsonwer.lth Edison (CC) has recognized, since 1971, that an upward trend in occup'ational radiation exposures at the Dresden Station was '= developing. Dresden Station exposures for 1972 and 1973 were 700 man-Pe:1 and 900 msn-Ren respectively and future occupational exposures are expceted to increase at about 10% per year. l CE attributes a significant portion of its occupational exposures to the high radiation levels surrounding the primary coolant system and =u.: I the proposed decontamination is expected to result in a significant au..: dacrease in these icvels. A. r:::.:s jjip=x: L oPFfC 8 > gge,4,,q, [ SURN awe % 6ars > .;;2 TE, Ftt:n AEc 315 (Rev. p.53) 0240 W u. s. aovenwuent reearine orreces sera.ese.see 10e10 Pgg p
c:- I r = r s b 5 (% =.; g q. c.q.7yc. ~ ~ T..E.;=" t 'nn: n n- .==lf=, Program Goals and Participants - W. P. Worden - t'-arealth. Edison (=25 2. These CE has established four gosla for the decoatseinstion program. are: p =....r. RaIuca radiation levels to improve plant acesssability. .g.;.;i g a. =_s.. w Ensure future safe and efficient operation of Dresden 1. H b. 9gZ:k Develop and prove techniques usable on other reactors. 7 =t:=5f c.
- =; 1 d.
Encourage broad vendor, manufacturer, and consultant 3$ participation. MN g.1 After evaluating alternative methods such as mechanical cleaning, glQ j } water flushing and operational techniques CE selected a chemical decontamination technique for Dresden 1. The evaluation showed that W[ .f=MJ l the alternative methods would not provide the level of deconta=teation ..a jj and uniformity of removal required. =5E; m.......j CE has selected the Dow Chemical Company as the prime contractor to
- 3, Suntac Nuclear
"~] implement the decontamination program at Dresden 1. Corporation has b'ecn selected as a subcontractor and will carry out ~ .m,,, ""~ the actual decontamination work. Additional Comunavesich Edison consultant.a include: D. G. Bridenbaugh of General Electric Company,
== T. A. llendrickson of Burns and Roe Inc., Craig P. Cheng of Argonne 5 National Lab., and Roger Stachle of Chio State University. 21:
- =n-l 3.
Program Gutline - D. E. Harmer - Dow Chemical Company .. =..; The chemical composition and physical properties of the deposited layer of corrosion prodt. cts have been detemined using components removed from the Dresden 1 primary coolant system. The deposit The composition is spinel, nickel or chromium substituted ferrite. 4 I material is present in the form of a very hard, tightly adhering = The thickness film uniformly distributed throughout the system. of the deposit varies with a maximum of approximately 4 mils. E=A The total quantity of the deposit is estimated at approvimately 1100 lbs. The predominant radioactive species present is Co-60 with lesser amounts of Co-58, Un-54 and other activated 304 stainless The total steel constituents and impurities also being present. The gEunE curie content of the deposition is estimated to be 3000 C1. EH-conceptual design of the decontamination facilities and rad waste fr.). 3 l cleanup systems will acconnodat< quantities of activation product.s -^1 in excess of those anticipated to allow for uncertainties in the "L:. predicted quantities. Or reCE V l svanaus > 1.ur r man > f' y
- u. s.Govemmuant Paimisme orrscss teF4 528. tee Forse ABC 318 (Rev. 9 53) AECM O240
Il I Id i
- :: ::3 bi* E
- =?:
- g
[ 1 3-W The Dow Che"lical solvent development program initially investigated hg the acceptability of existing solvents normally used in the nuclear .:g.; Because of the unique problems associated with the use = = :: industry. a=f nation solvent in the primary coolant system of a 91 reactor which is to be returned to operation and the Inrge volumes of of a dscon ( = = - solution and rinse water required, the following criteria were }-{ established for solvent selection: The solvent should provide.a decontamination factor of 100 a. to 1000, The solvent must provide a high dissolution factor to prevent redeposition of the corrosion products within the primary coolant b. - = = -
- system, The solvent must not cause unacceptable corrosion of the base
~ c.
- metal, The solvent should utilize a cingle solution treatment technique d.
+o minimize the quantities of vaste generated by the cicaning oaration. No existing solvent was determined to meet these criteria and Dow developed a new proprietary decontomination solvent for use in the Dresden 1 cleaning project. The new solvent has been tested on radioactive specimens from the J Dresden 1 primary coolant system and on representative sampics from Decontanination factors of 100 to 1000 have been n achieved with the higher DFs occurring'o'd the most highly contaminated other reactors. The tests thus far indicate that all specimens have been decontaminated to a residual radiation icvel of approximately items. 0.1 cPJhr, y, at 1 inch. Materials in the Dresden 1 primary coolant system have been systematically identified and categorized and their compatability Materials with 129 distinct with the new, solvent established. l specifications, 34 representative metals and 8 other materials have been identified. A materials test program to investigate general corrosion, bi-metallic corrosion and stresscorrosion has been c [ E V:': !E ' rrica p c N:: sun =aus > f. f.:.
- u. a. oovanumany reinvene orrecs, in34.es, e 7
Form AEc 513 (Rev. 9 55) AECM 0243
ba ) ki E5=E / n-'.iD G?.=
- ~ L
_4_ 355il General corrosion - 29 alloys with 11 variations, 3d a. $: 5 b. Bi-metallic corrosion - 39 couples with 9 variations. [..,,...; .;-d Stress corrosion - 20 alloys with 11 variables. c. The material test program on the above representative samples was conducted at 275'F for 300 hours. The anticipated conditions for ..._l.; the Dresden cleaning will be 100 houra at a solution temperature .sgg of 250*F. The test corrosion rates observed were approximately 0.1 =s..g; mil for stainless steel and 1.0 mil for carbon steel. These rates ...::.5s are reported to be simMar to the rates expected with demineralized ]N_. [~_ water. E=~ Additional testing has been performed utilizing a dynamic loop with ]E@h simulated low flow, dead les conditions. Satisfactory decontamination Ti n was achieved on the dead leg coupons with no redeposition in the jfj low flow areas. _m. The D:rw solvent has been used to decontaminate the stainless steel secondary portion of a heat exchanger at the Argonne CPS reactor. f= This decontamination was successful in removing non-radioactive h.=Ei scale from the heat exchanger and has been referenced only for the {~~~~ purpose of demonstrating that methods have been developed for trans- '~~""- portation, use and storage of pilot quantities of the Dow solvent. and that no unacceptable corrosion probler.s have been identified in . 3 its use at CP5.
- Ei Initial preparationsfor the decontanination are underway at the r=-
r Dresden Station. The primary system is being surveyed to deternine the location of all crud deposition and dead legs. E-T:. Dresden 1 contamination is not considered unique a:aong boiling water reactors. It has become a problem because Dresden 1 has been in service longer than other reactors.
- f. sinilar trend of crud buildup
[. R is being observed at other B'Es.
- =:
4. Report of Consultants - General Electric Company - D. G. Bridenbaugh = The General Electric Conpany has been involved in the program for the past three conths. GE is providing consultation in the following areas:
== =; a. Safety aspects,
- =
k. i;tir b. !!aterials cow atability. , _..e= = 5 '55 ~l n=M: \\
- . =
mars D' r.,. uc.m ..m acxo m
- o................,...o,-o...........
) w ...e = ~5-c. Materials surveillance program, d. Review of procedures and pilot testing, ).[ e. Post cleaning return to service review f. Final evaluation of the program. To date General Electric has reviewed the Dow Chemical Company's corrosion data, initiated a test program to establish the long term efn.ct of the project upon future reactor operation, and begun its review of the procedures to be used for the decontaminatica. General Electric's current opinion is that the program is reasonable, the pre- = paratory work is thorough, the solvent is compatible with the materials present in the system, and the information to be gained is useful. Because of the above conclusion, CE supports the decontamination program at Dresden 1. Dr. Craig Cheng of Argonne National Lab. reported that he had used the Dow solvent to decontaminate saarles taken from the Dresden 2 and Quad Citics 2 recirculation pump bypass line. The sampics were cicaned to approximately 0.1 mPJhr and were able to be released for unrestricted laboratory e m ination. Dr. Cheng's review of the Dow corrosion data plus his own evaluation of the solvent indicates that = the corrosion caused by this solvent is the sane as that caused by deioni:cd water. Dr. Roger Stachle indicated that his review of the Dow 300 hr corrosion data convinced him that no acceleration of any attack nochanism, beyond that caused by pure water, is produced by the Dow deconta=ination solution. 5. Discussion of the Dresden 1 In-service Inspection Program R.F. -Janecek - Coc=onwealth Edison The in-service inspection program at Dresden Unit 1 is currently bcing carried out on a frequency until ECCS modifications are completed. The third portion of the first cycle of three inspections is due 6.r completion in early 1975. However, Co=comicalth Edison will request authorization to delay this inspection until Fall 1975 to coincide with its next refueling outage. Eccause of the cy.istence of high icvels of radiation in sone arAas, CE will request that the following additional itens be deleted from the 1975 in-service inspection: t k.. or ric a
- s cawame k oare >
.I Foran AEc.Ds (Rev. 9-53) AICM O240 W u. s. oota mmusut samtime orreces s on.sas. nee
_g.
=.
-rl:.s m.! =:. :m ~ h5=i= 6-
M db p
y== a. Category D - nozzle-to-vessel welds (4 of 4)
- ===
hE5 b. Category F - dissimilar metal welds (8 of 48) l =g fg2 c. Category 5 - piping welds (14 of 165) ~ ~r: - = =.; d. Category Tel - pressure containing welds in recirculation pump /.]_. 7.5.. c. Category M valve casings (4 of 13) =h CE will exs: sine all areas previously deleted due to radiation levels s=E in the inspection that will be performed prior to returning Dresden = Unit 1 to service after its deconta inntion. ]:: 6. Decontamination Project Schedule - W. P. L'orden - Commonwealth Edison "Sf:.f
- .=5 A tentative schedule for the Dresden 1 cleaning project was presented
.=; by CE. A preliminary licensing submittal is expected to be made to
- ...2 Regulatory in January 1975. Detailed licensing questions are anticipated
.u between May and September 1975. Regulatory approval is desired by Septmber 1975. The presently scheduled date for initiating the actual decontamination operation is January 1977 with the return to service scheduled in July 1977 following a comprehensive system inspection. ,g..; =: 7. Licensing Concerns Identified During the Meeting
- =
=.5 During the meeting the Licensing staff identified areas of concern ""= which Cornonwealth Edison would need to address. These items are su=uarized below: E! .g The licensee's submittal should describe any environmental it: pact a. anticipated during the progran and should identify those measures that will be taken to assure that the future safe operation of the reactor will not be jeopardized by the chemical cleaning. b. The submittal should contain an estimate of the radiation exposures
- ="
anticipated during the decontanination operation. Both onsite and offsite Man-Ren esticates should be.provided for all phases of the program including the preparation, decontamination, onsite 5 =. waste storage and processing, and the transportation of the residual a= radioactive wastes.
== c. Conaonwealth FAison should describe the radiation protection organiza-
===" tion and the program that it will implement to minimize occupational radiation exposure resulting from the decontanination operations. ' rrecs > o evanaus k
- =
- T*
- 272...
Fire AEc.)le (Rev. 943) A2CM 0240 h v. e.eovsanusnr eninvamo orrecas se74.eae.see
6 g3s: (Eh
- s:
n 57 ,:? 4* 1-5 =- d. The inspection and test program to be conducted prior to the %P ~ return of the facility to operation should contain provisions for ~ the pre-service inspection of the primary coolant system botstdary ,], and equipment important to safety. The program should include gsl=" surveillance capsules which will be evaluated periodically during subsequent reactor operation to detect any degradation of the
==....; primary coolant system properties that may have been caused by M the chemical cleaning.
==: 3; Paul W. O'Connor
- 4 Operating Reactors Branch f2 Directorate of Licensing
- 8e
=:..
Enclosures:
1. List of Attendees =E
== 2. Visual Aids ec w/ enclosures: See next page l l l iu.== ... =. U.;..: -
=
d.E Q :.+:. ExE p
=
L:0RB-2 ) L: RB-2 f o,,ee,, I PWO'Connor/t : DLZiemann 12/J3/74 12 174 aan * .uz..:.u. F&rm AIC-)ls (Rev. 9 53) AECM 0240
- u. s. oovsanasswr P.e=teme o,reese son.one.see
e ..=.. i-k.....i 5~~~.*:
- ..;
- p 7."% Tsi"
==5
===3: -ce w/ enclosures:
===$ l AEC PDR ""ll: l w ppg l RP Aseintant Direetors RP Branch Chiefs S. Varga T. J. Carter i=ri F. Schroeder TR Assistant Directors "r -- TR Branch Chiefs .r.$ j S. Kirslis, EP. .....ine: P. O'Connor '9IE Attorney, OGC RO (3) Docket 1-5 L Reading . ~.I ORB-2 Paading
- 4..:l..
RMDiggs ...;s; R. Fraley, ACES (16) Meeting attendees from PIG ..=:==. l
- =. -
i j u-.~.- i t l xin5?ir ~ +:i:
- =k
- =:'
- =::
_.f..-
- .:g:: ::,
[ i.!E...!' l ~-@fx g:;; -- - g.. [!!
- imii--?
=:. sik :-ii: =i-in "'C'* tuaMaws > _:= = Dave > '-??i:: Form AEC 318 (Rev. 9 53) AECM 0240 W u. s. oovs=MMsNT PRINTING OPFbCas9974 83090s
L @:E. x.-= (5.6=~ ,,s z.i
- w ;
- r
.:g ie=
. = -
== =:- ATTENDANCE LIST .g
- s
COMMOMTEALTH EDISON COSTANY
- =2Q iii=iziiil DPESDEN NUCLEAR POWER STATION UNIT 1
..;;=:.:; int 2 MEETING OF NOVEMBER 26, 1974 mggj
- =
e 55E28 COMMONWEALTH EDISON C019A.( AEC - STAFF 5 g Ed E "" Robert F. Janecek Paul O'Connor Warren Kiedaisch Stefan Pawlicki
- 7._
W. P. Uorden John Weeks
- 5Ess 2EEE Byron Lee Roy M. Gustafson James Abel John Ahlquist
~G.:. Riche.rd Emch .,g,3 ...:;;;2-4 EURNS AND ROE Villiam Kreger Karl V. Seyfrit T-Eh Tcm Z. llendrickson Karl R. Goller =s:55 Dennis L. Ziemann 255$ ARCONNE NATIONAL LAB. R. R. Maccary
- iEFEk Richard D. Silver 5"E [
Craig F. Cheng T. J. Carter .g[:5j '~~" Frank Almeter CENERAL ELECTRIC COSTANY E. G. Case T. D. Murphy ~~EE~ Dale G. Bridenbaugh Stan Kirslis = = " David M. Dawson Don lloatson
- g N5 DOW C11EMICAL CO'IPANY
. g;
- ==
C. F. MacGowan Raymond W. Boyle
=
Thomas D. Boyce
=:."
Marc Snyder A. David Nesbitt ..,[' ; Oswald Anders g. I SUNTAC NUCLEAR g=E=' l Jim llolloway
== l
- -===
l l Er
===- Ef:-: mer-
- Y 59l
=:==. a e}}