ML20045A429

LER 93-003-00:on 930505,new Source of Natural Gas Introduced within 0.5 Miles of ISFSI & Reactor Bldg W/O Prior NRC Approval.Caused by Field Routing of Natural Gas Pipe.Well Isolated by Well operator.W/930603 Ltr

ML20045A429
Person / Time
Site:	Fort Saint Vrain
Issue date:	06/03/1993
From:	Holmes M, Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-003, LER-93-3, P-93049, NUDOCS 9306100243
Download: ML20045A429 (9)

Text

.

4

~

=; "A..

h Public Service

• 16805 WCR 19 1/2; Platteville, Colorado 80651 June 3, 1993 Fort St. Vrain Unit No. 1 P-93049 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Docket No. 50-267

SUBJECT:

Licensee Event Report 93-003-00, Final Report

REFERENCE:

Facility Operating License No. DPR-34 Gentlemen:

Enclosed is a copy of Licensee Event Report No. 50-267/93-003-00, Final, submitted per the requirements of 10 CFR 50.73 (a) (2) (B) .

If you have any questions regarding this report, please contact Mr.

M. H. Holmes at (303) 620-1701.

Sincerely, hDonWW. OlvuY Warembour Decommissioning Program Director DWW/JRJ Enclosure cc: Regional Administrator, Region IV '

Mr. Ramon E. Hall, Director Uranium Recovery Field Office Mr. Robert M. Quillin, Director Radiation Control Division Colorado Department of Hea)th 090040 l

9306100243 930603 i PDR ADDCK 05000267 -

1 S PDR

NRC FORM 366 LLS. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 ts oa EXPIRES 5/31/95 ]

. ESTIMATED BURDE N PER RESPON5E TO COMPLY WNH TH:S

!NF ORMATION CC4 LECTION REQUEST: *A D HAS. F ORW AHD I

" LICENSEE EVENT REPORT (LER) COMME NTS REGARDiNG BUHDEN EST: MATE TO THE INFORMATON AND HECORDS MANAGEMENT BAANCH (MNBB 7714! U.S. NUCLE AR MGULATORY Cf.NMS90N W ASHINGTON. OC 20*a55 0001, AND TO THE PAPERWORK Rf. DUCTION PRCUECT (3150 0104), OrFICE OF

($ee reverse for required number Of digits / Characters 10f each blOCb) MANAGEMENT AND BUDGET, WASHINGTON DC 2%n j l

F ACluTY NAME (1) DOCP.ET NUMBER (2) PAGE (3)

Fort St. Vrain Nuclear Station 05000 10F 8 TITLt. (4)

New Natural Gas Source Within One-Half Mile EVENT DATE (5) LER NUMBER (61 REPORT NUMBER (7) OTHER FACILITIES INVOLVED (8) i f AG)Uf 4 NAMti DUGPET NUMBER I MONTH DAV YEAR YEAR f MON'M DAY YEAR gg uGw nam m tTNuMBEn

~ 003

~

5 5 93 93 0 6 3 93 05000 l OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 6: (Check one or morel (11)

MODE (9) N 20.402to) 20.405tC) 50 73caH2)ov) 73 7i(e) ,

I POWER 20 405fa)(1)(0 50 36(c)D) 50.73(a)(2)(v) 73.71(c)

LEVEL (10) 20.405(a)(1)(n) 50 36(c)(2) 50.73(a)(2)(vn) OTHER 20 405(a>l1)(m) X 50 73(a)(2MO 50.73(a)(2)(vinHA) M'M

• Ab**d 20 405(a)(1)Dv) 50.73(a)(2)(n) 50.73(a)(2)(vm)(B) 20 405(aH1)(v) 50 73(a)(2)bu) 50 73;a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12)

NAME TF.LENNE NUMtdEH qmouae Ar.a Cooep M. H. Holmes, Project Assurance Manager (303)620-1701 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE S VSTE M COVPONENT MANUFACTUREn CAUSE SYSTEM COMPONENT MANUFACTURER N

l SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED l MON

• LA' *^R YEs SUBMISSION m yn. cown ExFcC'ED suBMts10N DATO X DATE (15)

ABSTRACT (Limrt to 1400 spacer,, i e., approximately 15 singie-spaced typewritten lines) (16)

On May 5, 1993, with the Fort St. Vrain (FSV) reactor permanently shutdown, defueled to the Independent Spent Fuel Storage Installation (ISFSI) and decommissioning actively in progress, a new source of natural gas was introduced within 0.5 mile of the ISFSI and the Reactor Building without prior NRC approval. This violates license conditions in both ISFSI Materials License No.

SNM-2504 and FSV Facility License No. DPR-34, and Technical Specification 5.11.

The event occurred due to field routing of a natural gas pipe from a new oil / natural gas well to a connection point which differed from the routing previously agreed upon by PSC and the well operator (outside the 0.5 mile restriction).

This condition was bounded by previous analyses of postulated ruptures of higher capacity natural gas pipelines much closer to the Reactor Building and ISFSI. The well operator isolated the new well until a new pipeline is installed, outside the 0.5 mile distance from these structures.

d NRC FORM 3ti6 15 92:

hRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION se, APPROVED BY OMB NO. 3150-0106 EXPIRES 5/31/95 LICENSEE EVENT REPORT (LER) on A oN c crow o 0s a TEXT CONTINUATION sy s,Ago g eg o,e g ugs ,vo y ness uv ss isy . 203 3 oo MANAGEMEvf ANo BJOGET. WASHIN3?ON DC 20$03 FACluTV NAME m DOCKET NUMBER (2) Lf R NUMBER del PAGE g3)

$6G.ENLAL REr$ca NUMBER NVVBER Fort St. Vrain Nuclear Station 05000 93 003 0 2 8 m w n. so.c. ., ,.w.a . .~. - .a wc m ma, o n BACKGROUND:

The Fort St. Vrain Nuclear Station (FSV) is being decommissioned in accordance with the Decommissioning Order issued November 23, 1992, and FSV Facility License No. DPR-34. Spent nuclear fuel is being stored in the Independent Spent Fuel Storage Installation (ISFSI) in accordance with ISFSI Materials License No. SNM-2504.

License Condition 2.D(4) of the FSV Facility License states that unanalyzed sources of natural gas shall not be introduced within 0.5 mile of the location where spent fuel or radioactive graphite core components are stored without prior NRC review and approval.

Administrative Control 5.11 of the Decommissioning Technical Specifications reiteraces this restriction with respect to activated graphite blocks. License Condition 16 of the FSV ISFSI License states that no new gas or oil pipelines shall be installed within 0.5 mile of the ISFSI without prior NRC approval, as evidenced by a license amendment.

In March, 1993, Barrett Resources Corp. (Barrett) requested permission from PSC to drill 3 new oil / gas wells on PSC property which would be connected to the natural gas collection system that has pipelines in the vicinity of the FSV Reactor Building and the ISFSI. One of these wells is FSV Well No. 30, shown on the attached Figure 1. Barrett holds a lease to mineral rights in the vicinity of FSV. Barrett stated that the wells, and associated equipment and piping, would be outside of the 0.5 mile ,

radii from the ISFSI and Reactor Building. PSC granted permission for Barrett to drill the wells and connect them to the natural gas collection piping system near FSV, based on a 10 CFR 50.59 safety evaluation that concluded the 3 wells and their associated piping and equipment would be outside of 0.5 mile from the Reactor Building and the ISFSI, and would not constitute an unreviewed safety question.

PSC's safety evaluation recognized that the FSV natural gas collection piping system, which would be supplied gas from the three new wells (16 wells total), includes piping within O.G mile of the ISFSI and the Reactor Building. The safety evaluation assessed the effects of the three new wells on the previous pipeline rupture analyses. The ISFSI SAR discusses the analysis of the worst case postulated collection pipeline rupture consisting of a 4 inch diameter pipeline located 540 ft. to the north of the ISFSI. The worst case postulated collection pipeline ruptures evaluated for the Reactor Building consist of ruptures of a 4 inch diameter collection pipeline located 930 ft.

t NRC FORM 366A (5'92)

NRC FCRM 366A U.S. NUCLEAR REGULATORY COMMISSION

+e2s . APPROVED BY OMB NO. 3150 0104 EXPfRES 5/31/95 ESTIMATED BURDEN PER RESPONSE To County wm4 Tws LICENSEE EVENT REPORT (LER) C v

'U "T$s% S E E RIEN f8u 5 o b s!1" E E

TEXT CONTINUATION

$$ N 8c5'Eu S 5'"'s* 72[T E *[e "$'S$$o'n" E THE PAPERWORK REDUCTION PACECT (3'So-cto4L OFFCE OF MANAGEVENT AND BJDGET, WASHINGTON. DC 20$03 FACILITY NAME 03 DOCKET NUMBER (2) LER NUMBt.R fel pagg gn EE M N hA. RE vtCN NuveEm NoveeR 05000 oF Fort St. Vrain Nuclear Station 93 -

003 -

0 3 8 rut w m w. v.w.a a. .m~ n.. e ~~c *n e o n to the southeast of the Reactor Building and a 6 inch line located 1340 ft. to the west of the Reactor Building. Postulated ruptures of 4 inch lines were modelled to release gas at a rate of 66 million cfd for 2 minutes, followed by steady state flow of 12 million cfd. Postulated ruptures of 6 inch lines were modelled to release gas at a rate of 120 million cfd for 1 minute, again followed by steady state flow of 12 million cfd. >

Modelling of plume dispersion for these postulated worst case collection pipeline rupture scenaries resulted in the determination that a flammable concentration of gas could reach a maximum horizontal distance of 197 ft. from the postulated  !

rupture location for the 4 inch line ruptures, and 230 ft. from the postulated rupture location for the 6 inch line rupture. It ,

was determined in the safety evaluation that the addition of the three new wells to the FSV collection piping system would not result in natural gas release quantities in excess of those conservatively assumed in the analyses reviewed by the NRC, and it was concluded that no new natural gas sources would be introduced within 0.5 mile of the Reactor Building and the ISFSI that were ne' previously analyzed.

Natural ga: relw ces from accidents involving individual wells were also pe de '" analyzed. Due to the lower flow rates from ruptures fed by .ndividual wells (1 million cfd was considered a maximum credible flow) compared to flows from the 4 inch and 6 inch postulated collection pipelines ruptures, accidents involving individual wells were bounded by ruptures of collection pipelines.

The NRC's safety evaluation for Amendment i!o. 82 to the FSV Facility Operating License states the following in regards to accidents involving individual wells:

"The licensee's contractor performed analyses which concluded that rupture of the 2 1/2 inch well piping would not produce flammable gas concentrations further than 120 feet from a postulated break and that detonation of the gas plume or explosion of a metering shed would not affect the structural integrity of the reactor or turbine building...The NRC staff has reviewed these submittals and agrees with the licensee's conclusions. The staff has also performed independent flammability and explosive concentration limit calculations which further support these conclusions."

Nac s:Ru mA ,u2,

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION

+sa, _ APPROVED BY OMB NO. 3150-0104 EXPlRES S/31/95 .

ESTIMA4D SgADEN PER RESAONSE TO Cow %Y w'TH Twt LICENSEE EVENT REPORT (LER) $$'As'EGE'~C"d5N'h5"cZiMR1's TEXT CONTINUATION

$$u"$$$'C$^YN5'* u

$!N"To7'*c S$$"

• iN THE PAPfpWORK REDUCTcN PROJECT istSo4% OFFICE OF M ANAGEMENT AND BUDGET, WASWNGTON. DC 20503 4

FACILITY NAME (T) DOCKET NVMBER (21 LER NUMBER lS) PAGE (31 g, SEQLENLAi REV $<04

- NUMBER NUVBER 05000 - OF Fort St. Vrain Nuclear Station 93 003 -

0 4 8 texr w - ,o.c. v.w.a . .~ an., a ue ,m o n PSC's safety evaluation clearly stated that the three new wells, and new piping and equipment associated with the new wells, would be located outside of 0.5 mile from the Reactor Building and the '

ISFSI. It indicated that the flow pipe from new FSV Well No. 30 would tie into the existing flow pipe of FSV Associated Well No. .

1, outside of the 0.5 mile radius. This was based on phone conversations between PSC and Barrett personnel. PSC formally "

transmitted the draft safety evaluation to Barrett in a letter i dated March 16, 1993, requesting Barrett to respond in writing t with any corrments on the draft safety evaluation. Barrett  ;

responded in a letter dated March 18, 1993, stating:  ;

"The information presented in the Safety Analysis is correct as to the hookup of the new wells to the pipeline system."

i PSC finalized the safety evaluation and it was approved by the FSV Decommissioning Safety Review and ISFSI Safety Review ,

Committees on March 25, 1993.

Drilling commenced on FSV Well No. 30 on' April 1, 1993. The pipeline connecting FSV Well No. 30 to the FSV natural gas collection piping system was installed between April 28 and May 4, 1993.

4 EVENT DESCRIPTION: L On May 5, 1993, natural gas was introduced from FSV Well No. 30 into its 2 inch diameter flow pipe that was routed within 0.5 mile of both the Reactor Building.and the ISFSI, as shown on l Figure 1. This pipe constituted a new source of natural gas i

installed within 0.5 miles of these facilities without prior NRC review and approval. PSC discovered the situation on the afternoon of May 10, 1993, when concerns arose regarding an excavation under the Goosequill Ditch. Upon investigation, PSC determined that the flow pipe from FSV Well No. 30 had been routed under the Goosequill Ditch and connected to the flow pipe .

from FSV Well No. 1 (refer to Figure 1), within 0.5 mile from the '

ISFSI and the Reactor Building. This was a deviation from Barrett's plans.

This event was evaluated and PSC determined that the condition was in violation of the FSV Facility License, the ISFSI Materials License and out of compliance with Administrative Control 5.11 of the Decommissioning Technical Specifications. PSC promptly ,

AM FOW 366A (5-82)

NRC FOMI366A U.S. NUCLEAR REGULATORY COMMISSION cs em APPROVED BY OMB NO. 3150-010s EXPIRES 5/31/95

'Estva*EO BJADEN PEA AESPONSE TO COVm v W% TwS LICENSEE EVENT REPORT (LER) Tv$si #As'lEnifELATUOi"I MCr2 t

Text conTmVATION QL",'$"S*"7$$"'EM7E"$M[NU rr'E PAP?pWORK AEDUC'ON PAGECT 13'50-C'04h OS8 ICE 08 vANAGivf N7 AND BJDGET. W8SMiNGrCN DC 20303

, ACILITY NAME git l DOCK ET NUMBER t21 LE R NUMBER 16) P AGE (3) g, g st asA.  % s or,

, NJueEA Nuvata 05000 OF Fort St. Vrain Nuclear Station 93 003 -

0 5 8 rur - . .c. ., . - ,....,~ % ,,, m n notified the NRC of this event on May 10, 1993. This LER is submitted in accordance with the requirements of 10 CFR 50.73 (a) (2) (B) .

ANALYSIS:

This event did not compromise nuclear safety at the ISFSI nor decommissioning safety in the Reactor Building. The worst case event which could have occurred, associated with the new natural gas source, would have been complete rupture of the FSV Well No.

30 2 inch diameter flow pipe at its closest point of approach to the ISFSI (approximately 1630 ft.) and Reactor Building (2408 ft.). Such an occurrence would have been completely bounded by previous analyses of flow pipe ruptures at the wells nearest the ISFSI (1163 ft. away) and nearest the Reactor Building (1184 ft.

away). Although an individual, newly completed, well typically produces approximately 150,000 cfd of natural gas, these analyses conservatively assumed a natural gas release rate of 1 million cfd (694 cfm) from a sheared flow pipe at the closest wells. It was determined that such a release would not result in a flammable concentration of natural gas near the structures of concern and hypothetical detonation of the gas cloud would not produce a significant overpressure at these structures.

Due to its distance from the structures of concern, worst case rupture of the FSV Well No. 30 flow pipe would have no effect on safety.

CAUSE:

The cause of this noncompliance was failure to adequately communicate understandings reached between PSC and Barrett with field personnel laying the pipe. Field routing of the 2 inch flow pipe used the most direct path, along the east side of Weld County Road 19 1/2, connecting to the flow pipe from FSV Well No.

1. However, this connection involved a different flow pipe path than that previously discussed and documented in PSC's safety evaluation. Also, PSC did not require Barrett to submit detailed routing plans of the FSV Well No. 30 flow pipe.

S

. = :au mA. n

NWC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 EST1uA*ED BJADEN PEA 84ESPONSE TO CouptY w'TH Tks LICENSEE EVT!NT REPORT (LER) $ % 7'I D El % '5 E AoE S U ' E E 0O7"'r^c't TEXT C' 'NTINUATION o a

$$ 2S 0'c"o*Ev' THE PAPEAWOAst AEDUCTON PsCECTs'"'SSU'o"ToD o*S401041 OFFCE OF uANAGEufNT AND BUDGET. WASWN37DN. DC 20503 f ACILITY esAME p)

DOCKET NUMBER (2l LIR NUMBER tel PAGE g3)

SE 3wE NT.A. RE cs,0N NvuBEA NgusEn 05000 OF Fort St. Vrain Nuclear Station 93 ~ 003 0 6 8 rw w n , c. ., , w.a . .~. coo . e wc ro- m, o n CORRECTIVE ACTION:

Barrett isolated FSV Well No. 30 at the wellhead at 7:30 a.m.,

May 11, 1993. This prevented supplying the new pipe within 0.5 mile of the ISFSI and the Reactor Building with gas and oil from new FSV Well No. 30. This action did not depressurize the new pipe, which was pressurized from FSV Well No. 1.

Depressurization of this piping was not considered warranted from a safety standpoint, since the new flow pipe is substantially further from the structures of concern than those previously analyzed, as discussed above.

Barrett has committed to maintain FSV Well No. 30 isolated until -

its flow pipe can be routed outside of the 0.5 mile radii, and connected to the FSV Associated No. 1 flow pipe, as originally planned. A survey has staked out the 0.5 mile radius from the ISFSI (which is more limiting than the 0.5 mile radius from the Reactor Building) in the area of interest. It is anticipated that the new pipe will be installed and FSV Well No. 30 returned to service in early June, 1993.

PSC has informed Barrett that for future wells, survey teams will stake out the 0.5 mile radii prior to installation of new sources of natural gas which could potentially be placed within 0.5 mile of the ISFSI or Reactor Building. PSC will also require detailed pipe routing plans for proposed natural gas / oil wells located within 3/4 mile of the ISFSI or Reactor Building and located between the South Platte River and St. Vrain Creek, and for any natural gas / oil piping planned to be routed within this zone.

NRO FOAu 366A 5 82,

NWC FpRM 366A U.S. NUCLEAR REGULATORY COMMIS$lON is tai APPROVED SY OMB NO. 3130 0104 EXPIRES 5/31/95 Esruano sv cEN a *En mEspoNst 70 cow %V W'N NS l

LICENSEE EVENT REPORT (LER) wscava m courc?)oN mEcutst. So o was FopwamD TEXT CONTINUATION couvws asse~o su'a.N esware to r a asoauaroN 4%o RECoAOs uANAGEMENr e MNCM #wNet met u s NUCLEAR asswe=< couw ss>cN esser

• aswatoN nossseoot oc,socio.i *No te crect or

-e na.e wean scoucroN is vasaofuf NT ANo svootT, waswNoroN oc teses.

sacaLITY Naut tip l DOCRt7 NUM51412) }l LAN NUMDEM son pass in g, u uNna, ac.:scN NJMGE R Nvustm 05000 Fort St. / rain Nuclear Station 93 - 003 0 OF 7 8 ,

ram,, - .m. .. ,. ,.. . .. .. ., ~~c i.- - ii n ST. VRAIN CREEK ff p FSV WELL NO. 30 (NEW) 1 i

2 INCH FLOW PIPE!s - f FSV WELL NO. 30-g GOOSEQUILL DITCH ,'

(NEW) 't /'

/

/ $\

• l

/ \

1/2 MILE % '

i i MET. TOWER '

t FROM ISFSI- '. I

? '

'. \ t i \ FSV WELL,I ABANDONED / NO. 1

'kFARMHO e -- -

b. e FSV ASSOCIATED "

NO. 1 WELL +

g

~~~~"'"~"~~~~~~~~l 2 1/2 INCH FLOW PIPE, I 4" FSV WELL NO. 1 .

L __ Iprm y.

[ g, N ygow 'M---i l SEPARATORS *

\ PIPES

' I g\

g CONNECT [#

4 INCH COLLECTION

.._~~~~,'

i

\ PIPELINE

/

1/2 MILE FROM% / \\gi REACTOR BUILDING e 7373g

( i

[

3 EY STORAGE PONDS l

i i l \

6 INCH COLLECTION-+,

s i L  : q j >

PIPELINE \

i I

j I

J i e

i REACTOR

( '

_ g BUILDING t___

s VISITOR r -

', CENTER " l

,j li

'-~

s I. WELD COUNTY ROAD 19 I/2 FIGURE 1 h4C FoRW 366A t$ Oh

I

. ~

NRC FORY 366A U.S. NUCLEAR REGULATORY COMMISSION f5 82:. APPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 ESWATED BURDEN PER RESPONSE TO COMPLY w'TM TH:S MORMATCN COLLEC*lON REQUESE 50 0 HRS.

LICENSEE EVENT REPORT (LER) CoMvEN s aE2uems BuRoEN EswATE To T E mFORMAmN FORWARD TEXT CONTINUATION AND RECORDS MANAGEMENT BRANCH (UNB9 7714). U E. NUCLEAR REowoRv COuu sscN. wAs-NotoN. oC Posss.oooi. ANo TO THE PAPERWORK REDUCT ON PROJECT Q1SO4104 OFFICE OF M ANAGEMEati AND BJOGET, WASHINGTON. DC 20*503 F ACIUTY NAME ol DOCKET NUMBER (23 LER NUMBER (S) PAGE (3l y g LEQUEN T. A, red!5CN NUMBER NUMBER 05000 OF Fort St. Vrain Nuclear Station 93 003 0 8 8 tut ca n. .c.c. . ,.n,.a a. .on,. an ., ~~u.<,,, uu, o n J.

h R. Johns d-Project Assurance hrY0 H. Holmes Y

@r M.

Manager, Project Assurance

0 W $ nan tu m

^

D. W. Warembourg7 Decommissioning Progra irector 4

9 d =

NRC FORU 3%A (S-92;