ML20055H490

Forwards, Decommissioning Rept Wpi Open Pool Nuclear Reactor Facility, Per 10CFR50.33(k)(2)

ML20055H490
Person / Time
Site:	05000134
Issue date:	07/25/1990
From:	Mayer J WORCESTER POLYTECHNIC INSTITUTE, WORCESTER, MA
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9007260279
Download: ML20055H490 (15)

Text

{{#Wiki_filter:hhit o, I ns. m s. cm a., r.E. pucson NUCLEAR -ENGINEERING PROGRAM :- '-~ N.E.DEPARTNENT WORCESTER,MA01609 (508)831-5460 i i s- ,3 (,' July 25.-1990 n s l USNRC Document Control Desk I-Washington, DC. 20555 i RE: License No. R-61 Docket No. 50-134 y i The decommissioning report required by 10CFR part 50.33(k)(2) is attached. This report describes the WPI Nuclear Reactor

Facility, develops a decommissioning model, and presents a method for providing financial assurance that decommissioning can be 1

accomplished at the end of operation of the facility. 'r If you require any further information, please contact me. Sincere y, .J/ John 4 Mayer Jr, Director Nuclear Engineering Program cc: T. S. Michaels PDNP t 9007260279 900725 PDR ADOCK 05000134 I PDC 4Q .n

4 i i ~ NUCLEAR ENGINEERING nummmer X.E. DEPARTENT WORCESTER, MA 01609 (508) 831 - 4 60 s DECOMMISSIONING REPORT WPI OPEN POOL NUCLEAR REACTOR FACILITY NRC License No. R-61 Docket No. 50-134 1988 amendments to 10 CFR require each holder of an operating. license to submit a report to-the Nuclear Regulatory . Commission (NRC) on or before July 26, 1990, indicating how reasonable assurance will be provided that funda will be available to decommission that facility. A subsequent Draft Regulatory Guide (DG-1003) states that "The initial cost estimate is not an exact accounting of the actual cost of decommissioning but is intended to provide an approximation of what decommissioning will cost at the proposed time of decommissioning". The amendments also require periodic updates of.the cost estimates for decommissioning during the operating life of the. facility. A detailed decommissioning plan is required roughly 5. years before the end of operation, with adjustment made to the funding plan to assure that the funds required will be available at the time of decommissioning. This report. describes the RPI Nuclear Reactor

Facility, develops a decommissioning model, and presents a method for

- providing. financial assurance that decommissioning can be accomplished at the end of operation of the facility. THE WPI,OPEN POOL NUCLEAR REACTOR HISTORY: The WPI Open Pool Nuclear Reactor ues mado possible by a grant of $150,000 from the U.S. Atomic Energy Commission in June 1958. The $70,000 cost of renovating the north end of Washburn Laboratory to accommodate the reactor was provided by the George I Alden Trust. The reactor ues constructed by the General Electric Co"pany and first achieved criticality in December of 1959. If nas initially licensed to operate at a thermal power leve: of 1 kw, and in 1967 the license was amended to allow operation at 10 kw. The operating license ces renewed in 1983 for a period of 20 years. s

1 In 1988-89, under orders from the NRC, the reactor fuel was-i changed from the origir.s1 93% enriched uranium to 20% enriched uranium. The reactor is used primarily in support of the undergrs ete education programs of the Institute. Courses in Nuc,'ar Engineering,

Physics, and Health Physics. have regularly scheduled class experiments throughout the academic year.

In addition. WPI's project oriented curriculum brings many i student projects to the reactor, including topics in: reactor

design, reactor

dynamics, neutron activation

analysis, and neutron radiography.

i Since 1987 -WPI's involvement in the DOE University Reactor Sharing Program has made it possible for high schools and other universities to make use of the reactor and associated facilities. DESCRIPTION: The EPI reactor is a pool type reactor, with an.8 x 8 x 15 J foot pool of demineralized water contained in an aluminum i lined reinforced concrete structure having 5 foot thick walls (see figure 1). The reactor core is at the bottom of the

pool, and consists of.22 fuel elements arranged in a 15' by 24" grid. Each fuel element in the core consists of 18 fuel plates made of an aluminum-uranium alloy clad with aluminum, l

Control of the reactor is accomplished by three boral (boron-aluminum)- safety blados and a stainless steel regulating blade. Insertion of any blade is sufficient to terminate the operation of the reactor. The thermal power produced by the core is dissapated by natural convection of the water in the pool. The average water temperature at full power is REACTOR PARAMETERS under 80*F. Because of the low power

level, fuel burnup has war. in.imai output to w been negligible thoughout the gin / ca'/s years of operation of the in imat o.airon na 14 m II n/c m '/s reactor.

Fast o.atror tion 2.a : to "'d A6 inch beam port for neutron 6 beam studies is provided in the cor. camma eme rat. io sen east wall of the pool, and a 5 foot square graphite thermal column that is used for neutron diffusion studies penetrates the west wall. l' l l l l.

l 5 a f a. \\\\ 1 'gl{ e t 7 sp

4 s

f,,// hl J2 \\ \\\\ 7.y h hk u n. gd j .g i 1i '\\\\+ m s s _a a:. t n s jj A i c a i g = e J m v <g.Q. PggpMP 6ft x s x 1 j / o'N N j \\ ' A '); E k h[e j]/p 2 4, -en-c 8= jc ~ \\. g c a 37, r r x 31/3J.4' !'l.83,1 k / ji 24"w;// 7\\ );I 'y\\ ' L s

• / k

\\ -\\ '\\ }m}~ L ..n-

THE DECOMMISSIONING MODEL Data collected [1]=for the 1988-89 conversion from high-i enriched uranium (HEU) to low-enriched uranium (LEU) fuel provide the foundations for assessing the parameters that inffmance the financial impact of decommissioning. DECOMMISSIONING DATE FOR PLANNING: Experience with the original (HEU) fuel has shonn the effects of burnup on fuel performance to be negligible over the 30 year operating period. Increased reactor usage within the constraints of the operating license (10 kw) does not change this conclusion.

Also, operation beyond thirty years is clearly possible, depnnding on the operating profile.. ^ Fuel burnup will not determine the schedule for decommissioning.

The reactor has just been refueled with low-enriched fuel (LEU), conversion of original console equipment is proceeding under DOE

funds, and facility upgrade funding is under discussion with DOE.

Given the long-range nature of these

changes, a

prudent planning date for decommissioning is at the end of the second 20 year renewal of the facility license, which occurs in 2023. Use of this planning date provides 34 years operation en the new (LEU) core, while the old (HEU) core operated under tn9 same service for a slightly shorter period, 29 years. There are currently no plans to change the mission or the operating mode of the reactor. Note that 2005 is a decommissioning planning date: the actual decommissioning date will be determined by evaluation of the contribution of the reactor to the educational mission of the Institute. This assumption of the date of decommissioning and other assumptions which are used in this decommissioning report will be reviewed regularly, as required by the amendments to 10 CFR and the draft guidance. Ultimately WPI will develop a detailed ' decommissioning plan" approximately 5 years prior to end of the operation of the reactor. The following sections discuss those factors which influence the decommissioning effort, and ultimately, the cost of that effort.

1. Conversion of the Worcester Polytechnic Institute Nuclear Reactor to Low Enriched Uranium, Thomas H. Newton, Jr'.,

WPI, 1989.

1 OPERATING PROFILE: j Examination of the first 30 years of reactor operation indicates the relatively low core burnup associated with the current educational use of the facility. The 'S' shape of the curve may be attributed to a combination of three factors: i - the 1 kw limit for the first 8 years of operation, - subsequent operation under a 10 kw limit. WPI NUCLEAR REAC'!OR FACILITY POWER PRODUCED, kwh(0 q - temporary decrease in N.B. program onrollment in the e """"' late 70's, and - a local agreement limiting use of the reactor above 1 kw during normal school hours. That policy frees adjacent lab space without the use of dosimetry. The planned installation of shielding =will permit use of the reactor at power levels to 10 kw during the normal school 8 day..The average power produced by the HEU core was roughly 250 ) kwh per year, and it is expected that the figure will o rise to 400 kwh per year until the end of the license. DECOMMISSIONING ACTIVITIES: Preparation of the cost estimate of decommissioning must account for all activities necessary for termination of the license. It is important to recognize that certain costs should not be included: l 5 costs for removal, renovation, disposul of non-radioactive structures and materials beyond that necessary for for license termination, and a costs of removal and disposal of spent fuel, which is considered an operational cost. It is convenient to look at those components which may contribute to the costs of decommissioning..

~ FUEL: i Although the costs associated with the removal and disposal of spent fuel are operating expenses, and not included in the decommissioning model, it is useful to examine the results of the 1988-89 fuel conversion to establish the nature of the radiological hazards presented. Similar figures would be expected for the 2023 decommissioning date. Following an 8 month cooling period, the hottest fuel element presented a surface dose rate of 2 R/h, and allowed the used of DOT-6M type shipping containers. The fuel transfer and loading was done with WPI staff, with a total personnel exposure of 0.2 man-rem. The highest individual exposure was 35 mrem. The fuel is owned by DOC, and the shipping

costs, including staff time, were roughly $8000 (1989 dollars).

CORE SUPPORT STRUCTURE: The core and associated neutron-measuring instrumentation are supported by the aluminum structure suspended from the reactor bridge (figure 2). Once the core is unloaded, the entire assembly may be lifted from the pool, separated, and sent off for disposal. Otho' than the aluminum structure, there are a small number of stainless fasteners and detector assemblies involved. A June 1990 measurement provides some indication of the residual radioactivity associated with the aluminum components. Two of the 1100 gram aluminum core box plugs were removed. These had been located in the reentrant corners of the. core box (positions D-7 and B-7) since the initial fueling of the reactor. In these positions they were immediately adjacent to the fuel, and in the reflector peak region. One plus was measured 7 days, the second 8

months, after operation. Wipe tests and surface dose rate measurements were

made, and a gamma spectrum taken.

There was no surface contamination, and the maximum rontact dose rates were less than 0.1 and 0.04 mR/h respectively. Extremely low traces of tungsten, barium, zinc, and cobalt were found. Activation of these trace elements and the fasteners in close proximity to the core will require low-level waste (LLW) disposal. l i .g.

\\ ', x.q ig)l-{ {.7 Q' i/e 6 ,,,y,,yg p,3yt 'k AllDT litl *!*4 f IX1fhttDN '- Y h j { A p ~ 2 ' ~.- l,, / cuu ~ suc, I 4* \\(L 'f f / tg (1 / Th. P N l 'T'4-Q htWOVA8'.C Fl0OR l't ATf.

v/

/=,s's { w x Rik OR >RfDGC SMPORfStAM =2 ' - 4 Whc#'. N;' T 4 9Jr 4

• h, O

w p M ION CHAMBER SUPPORT LOCATING PLAft N p, i }Y' GUIDE THIWBLE 1 SCRAM DAMPER - ?'.. I yi S. ( { J;:6;4* f. ;y. l s l t CONTROL SHAFT i N s0EINSION POST l [ Ij ~ """Is$ u"M " M ' o , f

J,;

y i CUIDE TUpt ASSEMDLY 'p) d ' j pion cHAvsta e'As W h core Asstusty r h

s. k

~ .,.f,.g.

• 'Y LocArino stoexs t

8J sf Nu d h \\ F i citare 2. WPI REACTOR SUPPORT STRUCTURE

4 OTHER STRUCTURE: In addition to the core support structure, the core end of [ the beam port and the core end of the thermal column may be [ . active. These sections are aluminum, with no fasteners, and the degree of activity will be determined by-the trace elements in the aluminum. The core box plugs which were tested-(above) are exposed.to the same flux levels as these tNx> components: consequently, minimum' induced activity is expected. POOL-STRUCTURE: The pool has a M inch thick aluminum liner inside a reinforced concrete structure. The. wipe tests of the plugs (above) indicate that there is no surface contamination of' the aluminum. 1 Regarding activation, the neutron flux approaches zero at the j side walls of the pool, so no induced activi+y is expected at-these locations..However, the pool floor is roughly 8 inches below-the - active portion of the fuc1' elements, and the resultant neutron flux in the concrete may activate some of the elements normally present in that material. The. pool liner is reinforced by a 3/8 inch thick aluminum plate in this region, which provides modest shielding for the concrete i Induced activity can be expected in the top few inches of the floor concrete under the-core. This region will also con rt ibute to the LLW which must be disposed. AUXILIARY SYSTEMS: The EPI reactor utilizes 1 auxiliary system: a pool water maintenance system. consisting of a demineralizer, associated

piping, valves, and a pump.

The pool water is normally circulated-through the domineralizer at a rate of. 10 spm continuously. The system resin is periodically regenerated, and-when necessary, replaced. The staff periodically checks water activity, and water samples are also sent out periodically to a state laboratory for analysis. No activity has been i measured in the pool water system. THE MODEL: Based upon the above review of the operation and assessment of residual radioactivity of the facility, the following summary presents the scope of decommissioning activity which will be required to terminate the license: 1 a.

we I. Prior to end of operation (and under operating expenses): 5 continue to monitor pool water activity and crud deposition. E develop models for predicting the time-based buildup of radioactivity, a assess, as required, the projected decommissioning date in terms of the best interests of WPI, s'make adjustments to the decommissioning model which reflect these changes, a adjust financial assurance package annually for inflation and other economic factors, and a five years before ceasing operation, prepare the decommisioning plan. i II. At end of operation and prior to decommissioning: E under operating funds, - so to " possession-only" license, - provide at'least one year shutdoan for decay, - then remove and ship fuel. E under decommissioning. activities: - complete all regulatory activities, - perform preparatory radiation surveys, - verify adequacy of decommissioning plan, - develop detailed work plans, - train workforce. III. Physical decommissioning activities: 5 preparation of the site, 5 removal of core support structure, e removal of othar components, if radioactive, a-removal of liner under core, e removal of concrete under the core to sufficient depth, E packaging of LLW for shipment. E shipment of LLW for disposal, and a final radiation survey, DECOMMISSIONING COSTS: An estimate of the cost of decommissioning the WPI reactor according to the above model was prepared by W.C. Leslie of-Westinghouse Installation and Construction Services. EPI will use this estimate ($70,000 in 1990 dollars) in establishing the financial assurance required by the NRL. The estimate is attached as Appendix 1. 7-

n:m-c ,it =d t'

b h

*] .t ~ ~ p_ 3 ,.a. 4 r-! --FINANCIAL ASSURANCE. ," ~ . WPI' - has': ; established ~ an irrevocable Letter of : Credit, with ' li I Shaunut. Bank'in the-amount of.$70,000 ' which.is equall to the . estimated 1990 cost-required.to decommission'the WPI reactor, o The' Letter.'of ' Credit is.-attached as Appendix '2 . arid : 'will-

1

~ ) m ,. remain in effect as required by the NRC. a 8 ).: ,s' ', J in 4 s g4 9,. n; (I f' ,j-. .) I i s a .T' I l r i e ? 1 ~! e, .i ,6

f.

0 } O /i-r j g

4 i i -I.

!'.( .f i i. i p i 1 a y .j f r ~ i 'h ,.3 l

4 A

[;, ' /,J J - ; = ~..-,

1 o APPENDIX 1 i k WeStingh0use Energ Systems Nucleaf 8n0 Adv8htt0 Electric Corporation '*"

• D" '

Bon 355 PmsDuc Pennsytva'wa 152310355 - NAID-IC-90-29 May 31, 1990 -} ' I r Professor John A. Mayer, Jr., Associate Professor Mechanical Engineering ard Director Nuclear Engineering E 4.uu: Worcester Polytechnic Institute i - 100 Institute Road HEM, MA 01609 t Dear Professor Mayers - Enclosed for your use is the WPI Reactor Facility W4==ioning/ Dismantlement ( Budgetary Estimate. ~ "? 'Ihis estimate is based on your facility, its geces Ly, operating level aM history and performing a relative ocuparison of rm ntly ocupleted training - reactor dismantlements. This estimate does not include any site restoration after termination of the facility NRC license. If you have any questions or require further assistance, please do not hesitate to call. Sircerely, s l ll /'/ L W. C. Ieslie, Manager Installation & Construction Services l - Enclosure l-oc: Marc Goldsmith ER3, Inc. I i 6 [ ---m- -e n -, n

' APPENDIX 1 c WPI NUC2AR RDCItR FACILITY DDCQtCSSI0tilNG/DISMANII2 MENT COSTS i RJDGE'IARY ESIIMATE l l 'A. Develop W 4==ioning Plan 1.0 Engineering- $10,000 Manmonths B. Site Support 1 - Supervisor .5 m 6,690 1 - Health Physics .5 m 6,960 i 1 - Tecnnician .5 m 6,960 2 - Electricians (80 hrs.) 9 $26.00

1. 0 W 2,080 2 - Iaborers (80 hrs.) 9 $26.00

1. 0 M 2,080 2 - Carpenters (80 hrs.) 9 $26.00 1.0 NM 2,080 i

2 - Iron Workers (80 hrs.) 9 $26.00 1.0 MM 2,080 29,200 1 Week Site Craft Training - HP/ Radiation & Project 10,000 Rapository Fees - Minimum Charge /Sitipnent'(1) Shilment 800 - 1000, 5000 lbs. 760 - Curie Content 0-5 2,650 4,210 Trardp uiation 3,000 L w rary - Work Enclosures - Matarials 3,500 [ 'Denporary - Ventilation 3,000 Waste Storage Containers 2,500 Consumables - Anti-C's, Tools 4,000 r l $69,410 l. l p f ~ L

~ APPENDIX 1 I o l k D b

• O -

,,v 'g--i - v r-

• vr

.v-- t W /ji b* l. = N s ' A. * 's j ,y., s g, g q 3,3 ,'{

s t~

h..

W y s. .4 %.Q** .r, ..,. m. y2 y( f o 3 e. o y'm' -- =-. "r .1 r y .jth

4.

y J & :.? ' '*. -. ' w. A--- A--

• l u-1
• 4 M

a '.s,. 8 i d f h w a

n

. v m

i Run1Dault atoddnt 3803 I '.,5 i 4 f,' g' 14p: t h.se v Aw r e o er M m t fn W y n' ..y ~ b f In' s g $2nInneuur W O o W ,O n-M m __. O ..,s. p V ' 8. ', 1 -C* \\** u T y e l-s j '., 1 Q 1 g~t l ~ ia.. M l m 4*

g. f.g O f"..,..

g g _'a, i ' ta. s ss ,y,. ...<a, r,. g .g*, M' t- .- b 4 IN ,a' ,w go y ) M e U 7)

==';.y n [._ '2 ~~ s -h g. A.- .e N w LA,. w

D,

(

5 O a '..s e t n. z 2 -x Z w W g A. O s \\ 4 M g, I,r' I I' U 3 H l l0 0m; i f', 4 8[ E k i.- _ e.3 o r OD J-. ' ' u r D C3 d D Do

yg-7 es o

,,.g z DO O 4 OD h o Do a 4 w A g 444 ) O 3 i { i I 1. b n i

i fo' g.. Mechanical Engineering Department WORCESTER - 100 Institute Road POLYTECHNIC "' ""'"' 13o33 E:'* 2[^ ^ INSTITUTE rAXd508) 831-5680 ,e A copy of Appendix 2, the Irrevocable standbv Letter of credit" will be sent by Shawmut Bank under separate cover. ^ / Jo A. Mayer, Jr. i I I 0D 71 (s $62,4 . _ _ _ _ _ _ _ _l}}