ML081090439
| ML081090439 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 04/15/2008 |
| From: | - No Known Affiliation |
| To: | NRC/SECY/RAS |
| SECY RAS | |
| References | |
| 50-293-LR, ASLBP 06-848-02-LR, Pilgrim-Staff-48, RAS J-78 | |
| Download: ML081090439 (5) | |
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Page I of 4 PDC No: 99-2 1 No&-"Q"F'I PDC /FRN
Title:
Excavtion for SSW Pinca Rapbae t tRFQ 01 scam Major E] Minor [
NARRATIVE (Rov. 2)
A. DESCRIPTION OF CHANGE a Problem Statlencnt: Salt Service Water (SSW) A Loop pipe spools JF 29-IH-4 and 5, and B Loop pipe spools iF 29-13-5 and 6, arc degraded and may require replncmcnt. Thcse sctions of pipe arc located in the yard area just to the south of the circulating water intn-c and sea1 well structvrcs, and iwill require a shored cxeavation approximate); J0 ft. wide by 90 ft. long by 12 ft. deep (400 cu..t. of material),
. Objectiv-slCritcria/Modif'eation Sco=: Thc obje icv of this modification is to dclincztc the work oeta i. to safely accomplish the excavazion for the pipe replacement scope, and to restore the work area to au arccppblc condition. This work scope may also cxpand to include temporary or othcr permanent modifications to dcal ith unforeseen conditions in the excavation. Rcplacemeat of the A and B Loop SSW piping, if required will be addressed under a separate modification package. Replacerment of the paved surf=ee and any requirements for supplcni'ntal fill to restore the subgrit" vnill be performed as a Mla.istar,.nce amivity under a separate package.
Design work is being performed in phases to support an r.:pedited schedule for impletcncrtation. Phase I is being released st this time. Ifadditional phases or other changes arc required, they will be released using the the FRN process.
Phase I - This scope coers the design of te cxcav-aion bounded by Piles IE through-9E, and IW through 9W. t; a-Ccs' toDA Loop pipe spool JF 29-11-.. and B Loop pipe spool IF 29-13-6. This scckoc was p ro* io usl ' re lease d fo r i. - .r.n ,,, -.. , . =%
ol UL.- --. . . . . ;_
1--, 1 incorporatcd now as pan of" 9 safety Classification 35 for possible pipe replaecrne "If ( _" 6 4a.
removal is being performed a W5-L3EfNo 99-35. Consequently. both I car be performed at thc s= OF *b**' lnwarsenor Thn follo,,.inL ,AriMi="ti tA N_
In-situ material mnd ba= -
placed around ard abA O W proectinin ftructuesig coiawk~lak i l "
Retaining structures suf
%vithrespect to dth SSW*
.zackfill outside Class I "T'. ssW pPIpis cons having a thickness of 4 !
i ntg -11c .v.k.R Lnk p_.a DOCKETED i IMNIP, Aoril 15. 2008 (10:00am)
OFFICE OF SECRETARY P I1 FMAKIN(q ANn Ar.ll il"ICATInNS ,;TAFF 150-5
Y~r 11~ZA 21of
Page 2 of ,
B, PROCUREMENT OF MAyIRIA[,CI OMPONENTS Fvcatacd soils will bI r.used to bed the ruplacmcn'*t, pipe and for bacldill. Flo%,v'blc fill may also be used in selected locatons, procur.d by CGI for Class I applic-ations, and per the GEl Specification for Class ii applicationts. Matvi.,s specifiýd for construction of the axcavation and associated support Structures may be procured Non-Q. It is anticipated that most of these matcrials will bc furnishod by the contractor C. CONTROLLED DOCUMENTSTRATNING AFFECTED a PNPS Procedures None a Vendor Manuals None
& Trchnical Specificatians: None a Priority A Design Documents: None a Priority B Design Documents: Drawing C20 a FSAR Sections: None a Operator Training: None
- Technical Training. None D. DOCUMENTS GOVERNING DESIGN AND INSTALLATION BECo Draming C204-R.EP
" GEl Drawing ES-I GEl Gcotcchnical Spccificauon for SSW Piping Replacemenm E SAFETY IMPACT DURING INPLEMENTATION
> .As discusscd prcviously. SSW pipe replacement actiitics will take place when the plant is in a cold condition, and dc*v heat removal is being performed indclndently by a third SSW return line inmiallced under Temporary Modification 99-35, Consequently. both the A and B Loop SSW return lines will be out-of-scrvicc, and not rcquircd to be performing. or -,ailableto perform,. safety functions during this time, As a result, safcty impacts during implementation are limited to the protcction of other safety related components which could bc affected by construction activities. This would include for cxmiple, tht Appendix R Manhole 28A and associated duct bank-s "tmmrciatcly djacenit to Ith,proposed c,.avation limit, and any other iterns having safet. rMated functions which are within, or in close proximity of. the uxcavation as determined by Engineering.
I SL, LFObh CONSTRUCTION Nlt3 20)Rc%- I Attachmentl .,I
- , Pagt 3 of4 Ex.'cavation for possible replacecrent of dciradcd SSW pipe will be accomplished ithin a soldier pileitimbcr sheathing structure, crigiccred to resist lateral saoil prssurc. During drilling and excavation activities, bot" the A and B Loop SSW return lines %,ilf bc out-ofrscrvicc, and not required to be performing, or nvailablc to perform, safcty Funchtio. Othcr safcr" related components which could be aficctid by construction Qcti.iuics arm protected by structures designed to Clas5 II over Class I criteria, Dig safe measures have includcd extensiwv drawinS searches to idenitil buried components. Ground detcction radar has bcen employed to augment this cfort, Holes for auger drilhng* ill be located by survcy and individually approved prior to drilling. These measures cannot guarantee all buried components have been identified and precisely located, lencc there is some potential that unidentifird items could be darmagd during drilling and excavation acxtitics. Nccrthclcss, rsonablc assurance is provide that safety related components, and components essential to power gencraton, will not be affected.
Fxcaatcd nmterials will be controlled inaccordance ,%ith radiological procedures. Maerials vill be stockpiled in a mnncr consistent wizi Security considcrations, Exca.atcd soil matcris will be rcplaced in accordance mili spccifimtions for controlled structural backfill Oco*.chnical spcrifications, drawings ard testing scrvices arc furnished by a qualified supplier under this modificztion package. Supporting analysis and calculations ae recc*ied and accepted under thc SUDDS/RP
, process.
- 0. rNSPECTION&*O!LD PONTSM/POSTWORK TESTING AND ACCPTANCE CRITERIA Backfllling around and over replacement SSW pipe sall not be permitted to proced until completion orfncessam, pipe installation inspections as may be required by the associated mnodifcation pakagc.'
M Testing of rnaterials for Class I bedding and backfill undcr, around and aba'e rcpmaerrncnr SSW pipe shall be pcrforrnd in accordance with the GE) Specification and BECo Commercial Grade Itm (COl) documntm., as applicable:
- Flowablc fill (aka controlled density fill) used for backfill shall be inspected in accordance with the g requirements ofthc applicable CGI, Ira conflict exists b==tvcn the GEl Specification and the BECo CGI, the
'.n buer shall have precede=c, th* pipe shall be properly anchored to pme= flotation. COI dedication for flowa-bit fill used for Class I applications shall be verified b%Quality Control personnel.
' Soil backfill shall re-usc ccavatcd materials, and in the scquncL spcificd in the -Plan for Radiologicnt Controls" (Narrative Paragraph J.). The bedding marenal providin support to the inve*t of the pipe shall compacted to the requirements or'the GEl Spccification for Zone A matcrial to the extcnt necessary based 0n disturbance of the subgradc, All oiier soil backfill around nai above the pipe shall be compacted to the requirements of the GEl Splecificaion for Zone B material. Compaction testing for soils used for Clms I applications shall be ,crified by Quality Control personnel.
Soil retaining structures designed to support tho eNcavation walls and considered Cl=s II. Managencnt Q, slall be inspcctcd'zo ensure recqircments or Lte drawings and specifications arc follow*.* In-process surveillance inspection on a sample basis shall be perfonued. No special testing is requircd Inspection of Class 11.Non Sarety-Rdeaied iwrk is not requirrd- }I '"'- "-c .,-:.n- ' ',.O if 9QjtM\NENI ~NPtlB ifiXTJ1A GPF- na (~iJf\10Ul N
.I 1;j,
.Q-.. V NASThis* w.'irk ii beng pýrtfoncd outsidc the RCA Nli3.2O Rev. I Attachmeln 4 K
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kAIZae- TIVE P)C-IN-,,z Pap4 of 4
- 1. INPUT FOR MAINTENANCE WORK PLAN
$c~ramion Pla
- General Th excavatuon contrmctor shall d&veiop a proposed plan for BECo aproval, for the location and configuration of stockpiles of ica, materials. Mtil stockpiles shall boa*tmid and controlled in a manncr whic precludes the possibility of da-aging components associated %withTenipomry Modification 99-35, or othr cmponents in tho yard area- Lines of sigh* required by Securiy shall be preserved to the maximum exwent possible, The plan shall include provisions to identify the locations of existing paving joints associated Milt previous repairs. This data likely mdieacs buried utilitics ithich. if not already sho*;n on BECo cxcavation dra%%ings, may rcquiro test pits to permit identification.
Holes to be augcred for soldier piles shall be located by a survey Each holc location shall bc approved by Enginocring prior to being drilled. Tc3t pits shall be dug by hand wrhen directed by the Engineering as neccssary to locate p ntial drilling obstructions. Excavatcd materials shall be controlicd in accordance with the radiological requircnsants. Soils siall be rc-uscd during the backfilling/rstm tio- phase to Che nmximum extent possible. As dctermincd by Engineering, no large rocks shall be permitted to be placed in contact with undrground equipment during backflling activities. The maximum size of gravel in the backfill within one foot of the pipe should be no lamcr than about 2",
- Plan for Radiological Controls Radiological considerations Aill requirt cxcavated materials to be segregated and controlled in a prescribed fashion,
'" This plan for control may be modified in-proccss at the direction of the RPM or designated rcprcsntat*ie. The foliowving definitions are applied to layers of materials to be nxca, tcd; atcerial Deosriorio Lawr A Bituminous asphalt paing materials
ýý I Layer B The 6" soil layer immediately bcnath LaUr A Layer C The 6" soil la*yer immediately beneath Layer B
'* Layrm D All other soils bencath Layer C Laycr A paving materials shall be siockpiled in a segregated area for pre-releasc radiological survey prior to disposal oft sie. Thc mcth*d of acxvation would prcfrably result in intact pieces of paving, minimizing the amounts or loose .aggrrgate %vhiehis more c-xpensivc to process for disposal.
Layer E3,C and D soil materials shall bc stockpiled in diffcren locations during the mxcavation process, These matcrials shall bc properly idcritified and controlled to prevent from being min.ed together. The backfilling sequence shall be as follows: Laver D soil materials shall be replaced first, follotved by Layzr C. followed by Laycr B.
BacKfill Steel piles shall be cut off npprexiniutcly 2 ft. below finish grade and abandoned-in-placc. Prcssure treatd timber sheathang may bc abnndnncd-io-place. timber sheathing not pressure Imeted.'shall be removed prior to backfilling.
Replacemint of cxcavated soils shall be accomplished in accordance %ith the following sequence: Lno..r D soil m.-terials shall be repl.ced first, up to its previous elevation. followcd by Lay'r C. follo~wd by Layer B CA-LUON: For marious roasons. it is expectcd thurc mtill be extra Layer D material remaining after it has bccn restored to pro-excavation lcevations TMis is acceptable and desirable since there must be a sufricient volinic to replacc all Laver C and B natermis in their original locations in thc excavation.
Backfill shall be compacted as rcquircd bý the specification. Where conditions may prccludc accomplishntenl of compaction requircmrnts by normal methods using mnuchincry, Engineering may approve alternatives to accomplish asi t.quivuhent rusult C
,SSuED FOFU Nl".20 Rev. I Atut,"i-ient 4