ML20135D708

Discusses Ltrs for Portsmouth Gaseous Diffusion Plant & 960419 & 0815,for Paducah Gaseous Diffusion Plant Requesting Exclusions of Areas within Usec Leased Areas from Criticality Accident Alarm Sys Monitoring

ML20135D708
Person / Time
Site:	Portsmouth Gaseous Diffusion Plant, 07007001
Issue date:	02/28/1997
From:	Pierson R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:	John Miller UNITED STATES ENRICHMENT CORP. (USEC)
References
TAC-L30576, TAC-L32009, NUDOCS 9703050426
Download: ML20135D708 (7)

Text

- . . .- . . . - - - - . . . - . . .

~70 9 001 s,

y pr p ee a UNITED STATES  !

s' j NUCLEAR REGULATORY COMMISSION .

2 WASHINGTON, D.C. 20665 0001 g

\ ,,,,, # February 28, 1997 Mr. James H. Miller '

Vice President, Production U. S. Enrichment Corporation l 2 Democracy Center

~

6903 Rockledge Drive Bethesda, MD 20817 i

SUBJECT:

CRITICALITY ACCIDENT ALARM SYSTEM MONITORING EXCLUSION REQUESTS - PORTSMOUTH GASEOUS DIFFUSION PLANT (TAC NO. L32009)  ;

AND PADUCAH GASEOUS DIFFUSION PLANT (TAC NO. L30576)  ;

Dear Mr. Miller:

1 1

This refers to your letters dated May 22,1996, for the Portsmouth Gaseous Diffusion Plant (PORTS), and April 19,1996 and August 15, l' 16, for the Paducah Gaseous Diffusion Plant (PGDP), requesting exclusions of areas wvithin the ' 3EC leased areas from Criticality Accident Alarm System (CAAS) monitoring.

Our review of your requests has identified additional information that is needed before final

,3ction can be taken. The additionalinformation specified in Enclosure 1 for PORTS and belosure 2 for PGDP should be prouacri before April 1,1997. Please reference the above TAO Nos. in future correspondence related to this request.

Please note that 10 CFR Part 76.89 requires criticality monitoring and alarm audibility in all areas of a facility except those that have been exempted by the NRC. The USEC certification application was required by 10 CFR Part ~/6.35(b) to include a plan for achieving compliance with areas of noncompliance with regulations applicable to the Gaseous Diffusion Plants. The NRC staff considers this approved Compliance Plan as a vehicle to bring USEC into compliance with NRC requirements, over an appropriate period of time, during which compensatory measures are implemented as prescribed in the Justification for Continued Operation sections of each Compliance Plan issue. Issue 11 of the PORTS Compliance Plan (DOE /ORO-2027/R3 " Plan for Achieving Compliance with NRC Regulations at the Portsmouth Gaseous Diffusion Plant") and issue 8 of the PGDP Compliance Plan (DOE /ORO-2026/R3 " Plan for Achieving Compliance with NRC Regulations at the Paducah Gaseous Diffusion Plant") recognize that criticality monitoring and alarm coverage is not provided for USEC leased areas identified in the above mentioned USEC exclusion requests at this time. Therefore, af ter March 3,1997, pending completion of our review of your requests, the NRC will not consider activities which are in comformance with the Compliance Plan to be violations. .

9703050426 970229  !

PDR ADOCK 07007001 / '

go011 glC HUEEN /f8

e James H. Miller If you have any questions regarding this matter, please contact Yawar Faraz for PORTS at (301) 415-8113 or Merri Horn for PGDP at (301) 415-8126.

Sincerely, Original Signed By Robert C. Pierson, Chief Special Projects Branch Division of Fuel Cycle Safety and Safeguards, NMSS Dockets 70-7001 and 70-7002 Certificates GDP-1 and GDP-2

Enclosures:

As stated cc: Mr. Randall DeVault, DOE-OR Ms. Janie Benton, DOE-HQ Mr. Dale Allen, PORTS Mr. Steve Polston, PGDP DISTRIBUTION: w/ encl (Control Nos. 010S,040S) '

Dockets 70-7001, 70-7002 NRC File Center PUBLIC KO'Brien, Rlli NMSS r/f FCSS r/f SPB r/f GShear, Rlli CCox, Rill WSchwink, FCOB MWeber, FCLB G:\CASEXCLX.RAI

• See previous concurrence d.phl OFC SPB C SPB 4 "SPB 'FCLB Rlli SP$ SPB ,

NAME YFarak M orn DHoadley DDamon h, 'h bhartin RPihrhon DATE 24f/97 2/jS/97 2/26/97 2/27/97 2/'d /b 2/N97 2/2 f97 C = COVER E = COVER & ENCLOSURE N = NO COPY OFFICIAL. RECORD COPY i

I j

-_. - - .- -- . .- ~. -. _- - - - - -. -- -

February 27, 1997 a . .

l

r. James H. Miller l

V President, Production 1 i U. S. (nrichment Corporation 2 Dem% racy Center 6903 Roc edge Drive Bethesda, 20817

SUBJECT:

CRITI ITY ACCIDENT ALARM SYST MONITORING EXCLUSION

, REQUES - PORTSMOUTH GASEOU DIFFUSION PLANT (TAC NO. L32009)

AND PADUC GASEOUS DIFFUS N PLANT (TAC NO. L30576) l . Deser Mr. Miller:

1 This refers to your letters dated May ,1996, for the Portsmouth Gaseous Diffusion Plant (PORTS), and April 19,1996 d gust 15,1996, for the Paducah Gaseous i Diffusion Plant (PGDP), requestin exclusions of areas within the USEC leased areas from

, Criticality Accident Alarm Syst (CAAS) mo 'toring.

d I Our review of your reques has identified addition information that is needed before final ,

action can be taken. Th additional information speci d in Enclosure 1 for PORTS and  !

Enclosure 2 for PGDP ould be provided before April 1, 997. Please reference the above I

TAC Nos. in future rrespondence related to this request.

If you have any estions regarding this matter, please contact awar Faraz for PORTS at (301) 415-81 or Merri Horn for PGDP at (301) 415-8126.

j Sincerely, eMnst Signed By 1

Rob'ert C. Pierson, Chief Special Projects Branch Division of Fuel Cycle Safety l and Safeguards, NMSS s i

l Dockets 70-7001 and 70-7002 Certificates GDP-1 and GDP-2

Enclosures:

As stated j cc: Mr. Randall DeVault, DOE-OR  !

! Ms. Janie Benton, DOE-HO I Mr. Dale Allen, PORTS Mr. Steve Polston, PGDP

. DISTRIBUTION: w/ encl. (Control Nos. 010S,040S) l

, Dockets 70-7001, 70-7002 NRC File Center PUBLIC 1 KO'Brien, Rlli NMSS r/f FCSS r/f SPB r/f GShear, Rlll CCox, Rlli 4 WSchwink, FCOB MWeber, FCLB 2

G:\CAASEXCL.RAI

, *See previous concurrence lOFC "SPB 'SPB 'SPB , ,QLE} 6 'SFB SPp g lNAME YFaraz:ij MHorn DHoadley DDaN DMartin RPh son lDATE 2/26/97 2/26/97 2/26/97 2/ 27/97 2/26/97 7 /D/97 4

C = COVER E = COVER & ENCLOSURE N = NO COPY OFFICIAL RECORD COPY I

Request for Additional Information CAAS Exclusion Request Dated May 22,1996 United States Enrichment Corporation Portsmouth Gaseous Diffusion Plant Docket 70-7002 Please provide the following information:

Reference:

POEF-LMUS-10 Criticality Accident Alarm System Coverage and Exclusions,"

April 1996, D. M. D'Aquila and J. A. Rapp, Jr.

POEF-LMUS-10 divides the alarm coverage of the plant into five sections:

1) Areas covered by criticality alarm systems

2) Non-process buildings

3) Roadways

4) Cylinders of UF6 in certain storage yards

5) X-622T Water Treatment Facility (Section 2) EXCLUSION OF NON-PROCESS BUILDINGS in Table 2 (p.5) of POEF-LMUS-10 areas are specified that are to be excluded from coverage on the grounds that they "do not contain operations enriched to 1% or higher U-235, and 15 grams or more of U-235." Additional information is requested showing a commitment to practices sufficient to ensure that containers or pieces of equipment with material exceeding these limits are not brought into these areas. Information is needed showing that allindividuals who might, even inadvertently, move special nuclear material are trained in these measures.

(Section 3) EXCLUSION ON ROADWAYS FOR CERTAIN MATERIALS Four specific classes of materials are described in the section on roadways, each treated differently. With respect to Class 11, " materials for which spacing is required":

Is there a requirement for Class 11 materials to be loaded and unloaded from the transporting vehicles in areas covered by criticality alarms? Additional materials, diagrams, or images defining the type of objects that constitute Class ll material shipments are requested. Additional description of the structures which ensure the maintenance of required spacing during transport is requested. Information concerning the robustness of these spacing structures to normal vibrations and moderate mishaps is requested. What plans exist for measures to be taken by accident response teams to consider the possibility of criticality ir the event of a major upset of the '/ehicle during transport of Class ll materials?

Enclosure 1 i

I 2 l l

i With respect to transportation of individual items or components that may contain greater than a safe mass of 35U,2 such as equipment classified for Planned Expeditious Handling:

What commitment has been made, and what measures will be taken to ensure that such shipments will always be made under criticality alarm coverage? What will be done if a criticality alarm covering the planned route is temporarily inoperative?

With respect to Class I;l, Large UF, Cylinders, as long as no loading or unloading is done on these roadways, the primary concern is the possibility of cylinder damage during transport. Is such transport done in such a way as to preclude cylinder damage as a result of vehicle accidents? Con the cylinders be dropped during transport? What would be the effect of a vehicle fuel fire on a cylinder? Why is criticality alarm coverage of these l roadways not feasible? What accident response measures would be taken in the event of vehicle fires and accidents?

(Section 4) EXCLUSION OF CYLINDERS OF UF, IN STORAGE YARDS There are amounts and enrichments of UF6 sufficient to produce criticality in these locations. The Paducah GDP document KY/S-271 is referenced as the primary justification that an accidental criticality is not a credible event in these cylinder storage situations.

The arguments in KY/S-271 that criticality is of low likelihood do not provide a degree of  !

[ assurance high enough to warrant complete exclusion from CAAS coverage. Unless I additional information can be provided showing that cylinder damage producing holes larger than 1 inch diameter cannot occur, measures providing the function of the criticality monitoring described in 10 CFR 70.89 must be provided. If it is proposed that a criticality monitoring system providing continuous coverage as described in 10 CFR 70.89 is not feasible, the following additional information is requested:

1) Information is requested showing why continuous monitoring is not feasible. All feasible rearrangements and spacing of cylinders should be considered. Various locations and types of detectors should be considered.

Detection of skyshine, reflection, and other indirect paths should be considered.

2) Information is requested describing an alternative to complete continuous monitoring that provides assurance that: a) those areas that are feasible to monitor continuously are so monitored, and b) that measures are taken to detect and mitigate criticalities when and where personnel are present. This information should describe how inadvertent entry of unmonitored personnel is to be prevented at all times.

Request for Additional Information i

. CAAS Exclusion Requests Dated April 19,1996 and August 15,1996 United States Enrichment Corporation Paducah Gaseous Diffusion Plant Docket 70-7001 i

Please provide the following information:

Reference 1): United States Enrichment Corporation letter GDP 96-0172 of August 15, 1996 from R. L. Wooley to J. W. N. Hickey.

Reference 1 requests exclusions grouped into four categories based on the type of justification as follows:

Category 1. < 15 grams 23sU.

Category 2. < 1 wt percent 23sU.

Category 3. Probabilistic Analysis Category 4. Low Level Waste (CATEGORY 1) FACILITIES WITH LESS THAN 15 GRAMS 23sU AND (CATEGORY 2)

AREAS WITH URANIUM ENRICHED TO LESS THAN 14 For those defined areas that are to be excluded from coverage on the grounds that they  ;

"do not contain operations enriched to 1% or higher U-235, and 15 grams or more of U-  !

l 235," additional information is requested showing a commitment to practices sufficient to  !

ensure that containers or pieces of equipment with material exceeding these limits are not brought into these areas. Information showing that allindividuals who might, even inadvertently, move special nuclear material are trained in these measures?

(CATEGORY 3. a) CYLINDERS OF UF6 IN STORAGE YARDS If amounts and enrichments of UF, sufficient to produce criticality are to be stored in these I locations, then the following information is requested. The Paducah GDP document KY/S-271 is referenced as the primary justification that an accidental criticality is not a credible event in these cylinder storage situations. The arguments in KY/S-271 that ,

l criticality is of low likelihood do not provide a degree of assurance high enough to warrant complete exclusion from CAAS coverage. Unless additional information can be provided i showing that cylinder damage producing holes larger than 1 inch diameter cannot occur, ,

l l measures providing the function of the criticality monitoring described in 10 CFR 70.89 l must be provided. If it is proposed that a criticality monito, ring system providing continuous coverage as described in 10 CFR 70.89 is not feasible, the following additional information is requested:

l .

' 1)Information is requested showing why continuous monitoring is not feasible. All feasible rearrangements and spacing of cylinders should be

}

considered. Various locations and types of detectors should be considered.

Detection of skyshine, reflection, and other indirect paths should be f considered.

Enclosure 2

i

. i e

, , i 2

l

2) Information is requested describing an alternative to complete continuous monitoring that provides assurance that: a) those areas that are feasible to monitor continuously are so monitored, and b) that measures are taken to detect and mitigate enticalities when and where personnel are present. This information should describe how inadvertent entry of unmonitored personnel ,

is to be prevented at all times.

Are all roadways along which movements of special nuclear material above a critically safe mass are made covered by the criticality monitoring system?

(CATEGORY 3.b) C-710 FACILITY DRAIN SYSTEM The C-710 Facility drain system empties into the C-712 Acid Neutralization Pit prior to discharge to sewer systems. The rationale for exclusion of the C-712 Acid Neutralizat'an Pit by probabilistic analysis, is deficient in two respects. Additional information, which might adequately address the deficiencies is identified below. The two deficiencies are: 1) the probabilistic analysis is deficient due to lack of independence, and 2) the criticality evaluation may not be sufficiently conservative. j I

1) The probabilistic analysis argues that six independent human error events must occur to  !

have a cn'icality (see Appendix E). Inadequate information is presented to justify that l these evente are truly independent, since all 6 occur in the same room, Room 21. If the i I

same personnel 6rc involved as operators or supervisors, the events are not independent.

In principle, measures might be taken that would provide such independence. If such measures exist, please provide additional information demonstrating the independence of the discharges and of the supervisory monitoring of them. Please provide hazards analysis which attempts to identify ways in which independence might be defeated.

2) The criticality evaluation argues that 426.8 Kg of uranium is necessary in order for the I C-712 tank to be critical. The analysis appears not to have considered concentration of the uranium in a layer at the bottom of the tank. Rather it appears to have considered only the homogeneous distribution of uranium in a tank full of water. Since the single  ;

parameter mass limit for of 5% enriched UO 2 2F is 1.64 Kg of contained 2"U (43 Kg U). It !

would appear that only slightly more than this, in an optimal configuration, might be critical. Thus further information is needed to justify that 426 Kg is required to be critical in an unstirred tank receiving discharges that are not measured. -

To justify CAAS exclusion the argument is made that the likelihood of a criticality is less than 104 Certain types of events that might enhance the likelihood of criticality are not discussed. Among these are conditions or events that might lead to formation of layers or deposits of enhanced fissile content in the tank, leakage of the tank, events that might cause unusually low water levels in the tank, etc. Although many of these events may be highly unlikely, to achieve the goal of less than 10 8, all such unusual events must be addressed.