ML16341A091
| ML16341A091 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/06/1984 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Fraley R Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML16341A081 | List: |
| References | |
| NUDOCS 8407160191 | |
| Download: ML16341A091 (98) | |
Text
j s'
]I f
QR AEONS c<
P
~4 Cy e (Q Gp v
+~
~O
+~*~%
UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 July 6, 19B4 MEMORANDUM FOR:
Raymond F. Fraley Executive Director, ACRS FROM:
SUBJECT:
Richard H. Vollmer, Director, Division of Engineering, NRR DIABLO CANYON LICENSE CONDITIONS ON PIPING AND SUPPORTS When Diablo Canyon Unit 1 was granted a low power license, certain con-ditions on full power operation were imposed.
The activities required by these license conditions have been completed by the licensee and evaluated by the Diablo Canyon Peer Review Group.
Draft reports of the Group's evaluations are enclosed for consideration by the ACRS.
Although not license conditions, two other issues have been considered by the Group.
One concerns the adequacy of the Diablo Canyon Independent Design Verification Program in the area of piping and,supports and the other deals with certain programmatic issues.
The Group findings on those matters are also enclosed.
We will be prepared to address these issues in detail at the Sbcommittee meeting on July 11 and at the full Committee meeting on July 13.
We would appreciate the Committee views on the Group's findings and whether these issues should prevent operation of Diablo Canyon Unit 1 at full power.
Enclosure:
Report of the Diablo Peer Review Group
':. Richard H. Vollmer, Director
>'ivision of Engineering, NRR Canyon CC:
W. Dircks H. Denton E.
Case D. Eisenhut R.
DeYoung J. Taylor J. Knight I. Yin H. Schierling J. Martin, R-V T. Bishop, R-V r
8407ihOiqi.
8407ii'DR ADOCK 05000275 P'
"PDR'
~
~
1
Report of the Diablo Canyon Peer Review Group Introduction and Conclusion A.
License Conditions l.
Review of Small Bore Computer Calculations 2.
Rigid-Rigid Supports 3.
Inactive Snubbers 4.
Thermal Gaps 5.
Piping System Hot Walkdowns 6.
guick Fix Program 7.
Small Bore and Large Bore Technical Issues B.
Independent Design Yerification Program Issues C.
Programmatic Issues
I I
~
~
Introduction and Conclusion On March 29, 1984 the EDO directed that a comprehensive review be initiated with respect to the large and small bore piping issues raised by Mr: Isa Yin, Region III inspector assigned to review allegations at the Oiablo Canyon plant.
The Oiablo Canyon Piping Peer Review Group (Group) was formed in response to this direction.
The Group consisted of nine senior staff engineers from NRR, IE and the Regions expert in piping and support design and quality assurance, and one expert piping consultant.
The Group first held discussions with Mr. Yin, following their review of his inspection report, and reviewed relevant licensee responses to sections of that report.
The Group then traveled to California where a public transcribed meeting was held with the li~see.
At this meeting the licensee presented its responses to the concerns enumerated in the subject inspection report.
Following the public meeting, members of the Group traveled to the reactor site in order that Mr. Yin might show them physical examples that represented his areas of concern.
The initial report of the Group was published on April 12, 1984.
In that report, the Group recommended seven specific actions to be required of the licensee prior to a full power licensing decision.
Those seven recommendations were the bases for the seven licensing conditions ultimately approved by the Comnission when low power operation was authorized~,~~
n "dan.wa ~~~ ~ ~g,eggy.
Review of the licensee's response to each of the seven licensing conditions was assigned to task groupswworking under the Group.
Additional consultants were added to the Group to provide the additional resources necessary to allow the task groups to perform concurrent review for each of the licensing conditions.
Each of the consultants selected has extensive experience in the design of p'iping and piping supports for nuclear facilities.
Two consultants were selected from each of the following:
Energy Technology Engineering
- Center, Idaho National Engineering Laboratories, and Battelle Columbus Laboratories.
Although some of the members served on one or more task groups, each license condition was assigned to an individual task group leader who, with the members of his task group, was responsible for full review and evaluation of the licensing actions requi'red to fulfillthe assigned licensing condition.
~
~ ', l In addition to the review of additional information from the licensee, the following task group'actions have taken place:
TASK GROUPS FOR LICENSE CONDITION 1.- REVIEW OF SMALL BORE COMPUTER CALCULATIONS AND LICENSE CONDITION 7 - SMALL BORE AND LARGE BORE TECHNICAL ISSUES.
Conducted audits of the licensee's review methods and results on two accasions (May 14 through May 18, 1984 and May 29 through June 1, 1984).
Further audits of small bore calculations were conducted the week of June 18.
1984.
TASK GROUPS FOR BOTH LICENSE CONDITION 2 - RIGID/RIGID SUPPORTS AND LICENSE CONDITION 3 - INACTIVE SNUBBERS This task group conducted an audit of the licensee's activities on May 21 through May 25, 1984 including a one-day inspection at the site.
During the week'of June 18, 1984 completed discussions with PGSE.
TASK GROUPS fOR BOTH LICENSE CONDITION 4 - THERMAL GAPS AND LICENSE CONDITION 5 - PIPING SYSTEM HOT WALKDOWNS This task group performed an audit on the licensee's response on May 21.through May 25, 1984 at the reactor site.
The task group also participated in field inspection and measurements of parts of the main steam system and the RHR system in both the hot and cold condition.
TASK GROUP FOR LICENSE CONDITION 6 - QUICK FIX PROGRAM This task group performed an audit of the licensee's actions during May 21.through May 25, 1984 including a one-day site inspection.
The findings of the task teams on license conditions are contained in Sections A.l through A.7 of this report.
+ p4,.I/~
A task team was also assigned to the issues raised~on the Independent Design Verification Program (IOVP).
Although the IDVP had been reviewed extensively 'by the staff, as reported in SSER 18, 19 and 20, issues were raised concerning the effectiveness of the IDVP in dealing with piping and piping support design deficiencies.
The task team discussed these issues with Mr. Yin, reviewed relevant material he had prepared, and met with Teledyne and Cloud to perform a detailed 3-day audit of the IOVP activities and work packages.
Finally, the task team discussed these issues with the licensee and IDVP participants in a transcribed public meeting on July 2, 1984.
The findings of the task team are contained in Section B of this report.
The final issue to be considered by the Group was one of a programmatic concern over the measures in place to control the work activities performed by'onsite engineering groups.
The measures in question, all part of the Commission's requirements in quality assurance for safety-related structures,
- systems, and components, included indoctrination and training, procedures and procedural control, audits, and design review.
A discussion of the resolution of this concern is provided in Section C of this report.
It is the conclusion of the Diablo Canyon Peer Review Group that the seven license conditions imposed on the low power license have been satisfactori ly addressed by the licensee, that the past staff conclusions on the IDVP remain valid, and that the programmatic issues raised concern-ing onsite engineering have, been resolved.
It is therefore the Group's conclusion that these issues should not prevent operation of Diablo Canyon Unit 1 at full power.
1 I
K C
SSER for License Condition 2.C.(ll, Item 1
"PG and E shall complete the review of all small bore piping supports which were reanalyzed and requalified by computer analysis.
The review shall include consideration of the additional technical topics, as appropriate, contained in License Condition No.
7 below."
\\
Sco e of Review The NRC staff and their consultants conducted a review of PGSE activ-ities related to License Condition 2.C.(11), item 1.
The review was performed by auditing a random sample of small bore pipe support calcu-lations which had been analyzed by computer analysis'nd requalified by PG8E staff in San Francisco.
The review also covered consideration. of the technical topics, as appropriate, contained in License Condition 2.C.(11), item 7.
The sample consisted of (21) support packages out of a population of (191) that had been reviewed by PG8E at the time of the NRC review.
In
- general, the supports were of the frame type and were analyzed utilizing the STRUDL computer code.
PGBE indicated that the total population of small bore supports associ-ated with item 1 of license condition 2.C.(11) is 357 supports.
. ~
n l
~
~
i 2
The review was based on the procedures contained in'G&E Instructions I-55, I-58 and I-59 and design criteria OCM-M9.
Basis for Evaluation The (21) pipe support design packages selected for review represent approximately Ill of the 191 packages that had been reviewed by PG&E and approximately 6X of the total population of small bore pipe supports which had been reanalyzed and requalified by computer analysis.
None of the supports reviewed were judged to require modifications for structural integrity or functional adequacy.
Based on the above, the sample size provides reasonable assurance that the remainder of small bore pipe support design calculations will meet the design criteria.
Document Review The 'review was conducted in the following two phases:
1.
Review of PG&E responses to the NRC concerns.
2.
Review of sample calculation packages.
The PG&E responses to the NRC concerns were contained in the PG&E submittals of April 27, May 10, June 11, June 29 and July 3, 1984.
Following the PG&E/NRC meeting of Hay 9, 1984 and subsequent discussions during the review period, PG&E have implemented review procedures addressing the NRC concerns related to this License Condition.
The procedures are contained in the following documents.
I 1.
PG&E instruction No. I-55, Rev. 2, "Instruction for the review of small bore pipe support calculation, Diablo Canyon Unit tl, 4/24/484.
2.
PG&E instruction No. I-58, Rev. 0, "Instruction for determining the angle BETA", 5/29/84.
1 3.
PG&E instruction No; I-59, Rev. 0, "Instruction for the evaluation of Licensing Condition No.
7 concerns - Diablo Canyon Units 1
& 2, 5/29/84.
4.
PG&E Design Criteria Memorandum (DCH) No. M-9, Rev.
10 "Guidelines r
for design of Class 1 pipe supports", 5/23/84.
The review of the procedures in these documents were judged to be adequate to address the NRC concerns.
The review of the (21) sample calculation packages was conducted by the NRC staff to verify the understanding and implementation of these procedures by the PG&E review engineers.
The staff identified discrepancies in some design calculations.
Some of ll these discrepancies were judged as insignificant since they did not violate the design criteria and were insufficient to affect the struc-tural adequacy of the supports.
Other discrepancies were identified to require a follow-up action by PG&E as outlined sn the following section.
~l.indin s l.
Deficiencies due to lack of proper documentation ot design judge-ments was identified in some design calculations originated by OPEG site personnel and reviewed by San I.rancisco engineering staff.
Ihe NRC staff concluded that these deficiencies dsd not impact the design adequacy of the supports reviewed and that no further action is required.
2.
Deficiencies related to some calculational errors were identified regarding assumptions of member properties and geometry input in the STRUDL compute code which is used for the analysis of pipe support structures.
The contribution.ot these errors was judged to have insignificant effect on the support adequacy and no further action ts required.
3.
PG&E review identified three cases where the ratio of L/t for angle sections in S/8 supports had exceeded'he limit of 270 as specified 1n the project criteria.'hese supports were modified to comply with the design criteria limit.
4.
Considerations of seismic loads on support structures resulting from the self weight excitation of the supports were accounted for in some supports, and ignored in others.
The staff determined that such considerations should be included in the evaluation of S/B and L/B pipe supports where it is significant.
The evaluation
- however, need not be completed before ascension to full power.
Subsequently, PGINE provided the statt with a program for the review of small and large bore pipe supports for effects of seismically induced self-weight excitation.
The program includes the review of all small bore calculations that use STRUDL analysis.
A re-analysis will be performed for those supports, where the effects of self-weight excita-tions has not been considered.
PGSE committed to complete this program by October 1, 1984.
With regard to large bore supports, a sample review of the 200 supports which had been re-evaluated for considerations related to item 7 of license condition 2.C.(11), it was determined that less than 10% of the supports did not consider the effects of self-weight excitation, and that the contribution of self weight ex-citation has little impact on the overall qualification of large bore supports.
the staff accepted PG8E position that further analysis was not warranted for large bore supports.
PG8E also committed to the revision of pipe support design criteria DC'-9 to require consid-eration of seismic accelerations on pipe support structures in all new pipe support calculations.
Conclusion Based oh the audit of small bore computer analyzed pipe support calculations, the statt concluded that the supports were adequately designed for anticipated loads as required for ascension to full power.
Technical concerns associated with License Condition 2.C.(ll), item 7 1
were properly addressed in the review effort performed by PGSE
X.O lICENSE CONDITION 2.C. (11)
ITEMS 2 ANO 3 Iteps
'2 and 3 of License Condition 2.C.(11) require that:
Item 2.
The licensee,shall fdentffy all cases in which rigid supports are placed fn close proximity to other rigid supports or anchors, For these
- cases, the licensee shall conduct a program that assures loads shared between these acgacent supports and anchors result in acceptable piping and support stresses.
Upon completfon of this effort, the licensee shall submit a report to the NRC staff documentfng the results of the program.
Item 3.
The licensee shall identify all cases fn which. snubbers are placed fn close proxfmfty to rigid supports and anchors.
For these
- cases, utflfzfng snubber lock-up motion crfterfa acceptable to the staff, the licensee shall demonstrate that acceptable piping and piping support stresses are met.
Upon completion of this effort, the licensee shall subm1t a report to the,NRC staff documentfng the results.
Sfnce both of these license conditions are sfmflar fn nature, this section will discuss the evaluation made of the licensee's
- methods, practfces, and submfttals relatfve to both Items 2 and 3.
X.l Background and Origin of Concern The design history of the Ofablo Canyon Nuclear Power Plant fs the key to understand1ng why rigid supports and snubbers would be placed fn close proximity to other rigid supports,
- snubbers, anchors, or equipment nonles.
The Dfablo Canyon Plant was fnftfally des1gned for a 0.2 g peak ground acceleration se1smic event which +as called the Design Earthquake (DE) and. a 0.4 g peak ground acceleratfon se1smic event wh1ch was.called the,Double Oesfgn Earthquake (DDE).
However, fn 19Tl, after a sfgn1ffcant amount of construction had been completed, the Hosgrf Fault was discovered offshbre, near the Diablo Canyon site.
The prox1mity of the Hosgrf Fault resulted in, the sfta's peak ground acceleration for a postulated seismic event fncreas1ng to the 0.75 g level.
This fs nearly double the previously
deffned OOK.
In addftfon, fn late l981, the lfcensee dfscovered errors fn'he sefsmfc desfgn spectra calculated for portfons of the contafnment for Unft 1.
These condftfons mandated a reanalysfs effort, leadfng to addftfonal supports to reduce pfpe stresses, valve acceleratfons, support
- loads, and equfpment nozzle loads.
As a result, fnstances arose where supports and anchors were located fn close proxfmfty to other exfstfng supports.
Typfcal fndustry practfce fs to desfgn a 1/16 of an fnch gap (on each sfde between the pfpe and restrafnt) fn the lfne of actfon of the rfgfd restrafnt fn order to accommodate axfal and radfal thermal expansfon of the pfpe. It fs also typfcal fndustry practfce to fgnore thfs small gap when performfng 11near elastfc pfpfng analyses.
However, for closely spaced
- supports, the concern ts that these supports could have sfgnfffcantly dffferent sf@ed gaps {or lost motfon) and the supports would not share the fmposed loads as assumed fn the pfpfng stress analysfs.
Thfs condftfon could possfbly lead to the overload and faflure of the supports, whfch could then result fn overstressed pfpfng not befng able to carry out fts fntended functfon.
X.Z Formulatfon of Lfcense Condft1on In response to allegatfons concernfng.fnadaquate desfgn consfderatfons wfth respect to largo and small bore pfpo supports, the NRC staff revfewed varfous analyses, prospect crfterfa, and performed an on-sfte fnspectfon at the Ofablo Canyon Plant, Unft 1.
The staff'oncluded, based on thfs audft (Reference X.1), that certafn practfces may not be fn complfance wfth NRC requfroments.
Subsequent revfew of thfs problem was accomplfshed by an NRC revfew group formed to address 'thfs and other Dfablo Canyon pfpfng related fssues.
Thfs group agreed that thfs fssue should not preclude crftfcalfty and operatfon at low power and dfd not, by ftself, demonstrate a generfc breakdown of desfgn effectfveness.
However, sufffcfent concern exfsted wfthfn the revfew group to establfsh Items 2 and 3 of Lfcense Condftfon Z.C. (11).
I
~
'E
~
X.3 Initial Licensee Revf ew of Closely Spaced Suppor ts The licensee established and fmplemented a program to identify all snubbers and rigid restraints located in close proximity to anchors and to identify, for large bore piping only, all snubbers and rigid restraints located close to rigid restraints.
The ob)ectfve of this effort was (a) to provide assurance that snubbers would function when located close to another support or rigid restrafnts would share the load with the support located
'I close to it and (b) to assure that acceptable piping and support stresses were maintained.
This program consisted of the following e1ements:
a.
Criteria - definition of the term "close proximity." and establishment of criteria to assure the supports were effective.
b.
1dentfficatfon, Inspection, and Analysis - identification of "close proxfmity" supports and fnspectfon to determine effectiveness.
c.
- Shfmmfng, as required, for rigid restraints to show compliance with. support effectfveness acceptance criteria.
for snubbers, compliance with piping and support allowable st~esses was assured by evaluating the need for snubbers or demonstrating functionality.
Items 2 and 3 License Condition 2.C.(11) were addressed by the lfcensee in Reference X.2 1
The licensee's response to Item 2 was the implementation of a program to shim those rfgfd supports with excessive gaps.
The program defined close proxfmfty as rigid supports within a distance of five times the nominal diameter (50).,
A total of 103 rigid supports located fn close proximity to other rfgfd supports,
- anchors, or equipment nozzles on safety related piping systems were-fdentfffed
=:
For these
- supports, the relative (or dffferentfal) gap between the subject support and the adjacent rigid support was measured in both a hot and a cold condition.
If the maxfmum relative gap was already less than or equal to 1/16 of an
- inch, no modification was deemed necessary.
If the maximum relative gap was greater than 1/18 of an inch, shim plates were added to either the sub)act 3
ar the adjacent support untf1 the re1etfve gap was equal ta or less than
~
1/16 af an. fnch.
Pfpfng two fnches and smaller was excluded from the program..'fmflarly, the lfcensee's response to Item 3 was the fmplementatfan of a program to assure that necessary snvbbers would functfon.
A total af 27 snubbers. located fn close praxfmfty to rfgfd supparts, anchors,, or equfpment nor@les on safety related pfpfng systems were fdentfffed.
Far Item 3, close proxfmfty was deffned as SQ for pfpfng less than 8 fnches fn nomfnal dfameter and 30 for pfpfng equal ta ar larger than 8 fnches.
Pipfng system reanalyses were performed by the lfcensee assumfng that the close proxfmfty snobbers dfd not exfst.
If the reanalyzed dfsplacement at the snubber lacatfon was greater than 1t16 of an fnch, the snubber fnstallatfon was consfdered acceptable, f.e., lock up would occur.
If the dfsp1acement was less than or equal to 1/16.af an fnch, the new calculatfans were reevaluated for pfpe stress, pfpe support, and valve acceleratfon acceptance.
If unacceptable, the actual manufacturer's test reports an lost motfon were revfewed for the unfque snubber.
The snubber's lost motfon (by tost) was compared to the reanalyzed dfsplacement to demonstrate lock up.
X,4 Inftfal NRC Staff Revfew The NRC staff's evaluatfon fncluded:
(1) revfewfng lfcensee submfttals (2} meetfng wfth lfcansee rapresentatfves and, (3) parformfng an audft fnspectfon at both the engfneerfng offfces and at the plant sfte.
Subsequent paragraphs fdentffy the ma)or fssues dfscussed durfng the staff's revfew.
The licensee submftted the proxfmfty crfterfa study whfch developed the M and 39 span lengths.'hfs study was revfewed by the staff.
The HRC staff dfd nat, agree wfth the screenfng crfterfa submftted by the lfcensae.
Ffrst, the staff noted that the 30 'screenfng crfterfon fm close proxfmfty snubbers on efght fnch or larger pfpe was nat acceptable.
The HRC staff agreed that SD was an acceptable screenfng crfterfon for all large bore pfpfng supports (rfgfd restrafnts and snubbers) fn close pt oxfmfty and the lfcensee agreed.
- Second, the staff dfd not agree wfth the lfcensoe's
screening criteria for large bore pipe supports fn close proximity to anchors (equipment noxcles, penetratfons, and p1pe support anchors) and requfrad that the lfcensee initiate a 100 screening criterion for both rigid restraints and snub6>>r supports n¹ T¹rg>> her>> p<pfng fn close proximity.o
'anchor s.
The staff dfd not accept the lfcensee's proposal to exempt Design Class k piping 2 fnches and less from review for proximity criteria.
After consideration that small bore piping generally utilfzes redundant supports and fs inherently flexible as evidenced by its performance in actual seismic events',
the staff required that the licensee use the following proximity criteria for the evaluation of small bore piping support effectiveness:
I a.
Small bore p1pfng qualified by span rule-supports within lOD of an anchor (equfpnunl nucclus, prrnutratfant, and pfpe support anchors).
b.
Computer analyzed sma11 bore piping-supports within 100 of an anchor (equipment nozzles, decoupled branch connections, pcnc5ratfons, end pipe support anchors).
For each of the above criteria, the need for appr'oprfate action, shfmmfng or snubber removal with system reevaluation without the snubberr will be performed for each fdentff'fed case.
, For pfpfng having any ¹Z>> configurations, the licensee 1ndicated that.
ft had conservrLtfvely considered the distance between adjacent supports as the dfstanca fn one dfrectfon only, and ignored the length of pipe perpendicular'o the two legs of the "Z" plus the flex1b111ty of the two fndlusfve elbows or bends.
Mfth respect to nozzle loads, the licensee stated that nozzle reactfons given to the vendor consfdered the effect, of supports and restraints near the nozzle.
Sfnce the licensee's sh1mmfng program for r1gfd restraints will insure small relative gaps typical of industry practice, 1t was decided to 5
-check a case where a snubber was in close proximity to an equipment nozzle.
gn,fact, only f1ve snubber installations (14-67SL, 4-39SL, 18-1SL, 4"98SL, and,l4-79SL).were initially identified as a snubber in close proximity to an equipment nozzle.
The staff reviewed Analysis No. 4-134, Revision 4
.dated January 7,
1984 and the associated 50 study calculation (analys1s without the snubber).. Since the prospect criteria (acceptable pipe stresses, support loads, and valve accelerations) were satisfied for OE,
Since nozzle loads are submitted to the vendor for approval, the piping stresses at the nozzle were checked in order to evaluate the potent1al impact of a nonfunctioning snubber.
Comparing values between the analyses with and without the snubber, the stress increase was extremely small (less than Z5).
Concerning the measurement of gaps on rigid restraints, the licensee indicated the following:
(a)
All the gaps'were measured whi'ie the plant was in cold shutdown.
Moat of the systems measured were cold systems such as component caol1ng water or auxiliary feedwater.
Those systems that do experience temperature increases were remeasured at ho. standby.
(b)
The above described procedure adequately envelopes the range of operating condit1ons and postulated accident conditions.
(c)
There was 11ttle or no change 1n the gaps when compar1ng the measurements taken at hot and cold conditions.
Gap changes up to the temperature 1n a postulated accident would be ins1gn1ficant.
The licensee provided additional details on the nine r1gid restra1nts with limited accessibility.
First, three of the nine restraints had been accessed and had already bean measured for relat1ve gaps.
Therefore, only six restraints remained.
These s1x restra1nts are all associated with the d1esel generator engine exhaust lines, The. licensee indicated that the
localized deformatfons that m1ght occur as a result of the possible gap misalignment and resulting load transfer between restraints would not compromfs'e the integrity of the piping for the 1ntended service.
Nth respect to the definition of snubber functionality, the 11censee 1ndicated that whenever the movement of the piping system was greater than 1/16 of an inch, the snubber fnstallat)on was considered acceptable.
In cases where the predicted system movement was less than or equal to 1/16 of an inch, the lost motion test result for that specific necessary snubber was compared against the predicted system movement.
In the evaluation of gaps, the licensee verfffed that the total suppor. installat1on had been considered for both rigid restraints and snubbers when determining the load actuated displacement (gap or lost motion).
The plant site inspection provided the NRC staff an opportunity to inspect the affected components on a first hand basis.
Iwtfth respect to Item 2, the NRC staff viewed a rigid restraint that had been shimmed.
This restraint (number unavailable) was near valves 90018 and 90038 of the RHR conta1nment spray discharge tfe.
The restraint fnstallat1on verified the implementation of the licensee' shfmmfng program.
fifth respect to Item 3, three supports were viewed by the NRC staff.
Support 14-67SL was a snubber that was in close proximity to an equ1pment nozzle and a rigid restraint.
Supports 4-32SL and 4-2SL were snubbers fn close proximity to rigid restraints98-14R and 98-16R respectively.
To verffy the information provided fn the licensee's submittal (Reference X,2}, the staff reviewed three pfpfng system analyses (No. 4-134, Revision 4 dated January 7,
1984; No. 4-135, Revision 2 dated October 15, 1983; and No. 4A-107 Revision 3, dated October 13, 1983 and the associated 5D study calculations (analyses without the snubbers).
These analyses dealt with snubbers 14-67SL, 14-83SL, and 11-33SL respectively (see AkcA~~<k 3-/
g~wcqcQ Sackese~
X:2}.
Five manufacturer's test records, which determined each unique snubber's lost motion, wore also reviewed.
These wer'e for snubbers 4-67SL, 18-1SL, 4-98SL, 14"79Sl.;
and 16-29Sl..
X.5 NRC Staff Review of Final Submittal The ffnal licensee submittal (Reference X.3) for Items 2 and 3 was revfewod by the NRC staff.
Based on the revfsed screening criteria, the lfcensee ident,ff fed z tutal af 4 Z3 i'fgfd Plkti'hfnts and '~
anuhhcro oo being close proximity suypu< Ls.
fprfgfd restra1nts reqy)ring shimmying to meef the hG+ e br e n iM&i6'cd ~i be ro~p pk d a y yuly I 3~ / t'S lfcenste's Droqram requfrements>
hll~
snuhho~~ wi~ <nd<cated to be efther necessary and functfonfnggIIIIIII'runnecessary sfnce reanalysis efforts demonstrated that pfpe stresses, support stresses, and valve accelerations were acceptable without the close proxfmfty snubber.
The lfcensee has committed to reevaluate all snubber 1nstallatfons as part of fts snubber optimization program.
The final submittal was acceptable to the NRC staff as an adequate response to Items 2 and 3.
'N.6 NRC Staff Findfngs The NRC staff found the licensee's programs for resolving Items 2
and 3, fncludfng the ffnal screening crfter1a for determfn1ng close proximity supports, to be acceptable.
The licensee's responses to all of the generated questions for both Items 2 and 3 were acceptable.
Tha Diablo Canyon Plant site fnspect1on enabled the NRC staff to view actual close proximity support fn<tw14~t<<~s and verify that the rfgf4 reotraini ohfmmfng program was indeed being implemented.
All inspected rfg1d rastrafnt and snubber support fnstallatfons appeared acceptable to the staff.
The NRC staff determfned that the three piping system analyses and the snubber manufacturer's test records provides sufficient demonstratfon that the 11censee adequately carried out its program of assuring snubber functionality.
Ffnally, the staff believes the lfcensee' proposed snubber optfmfratfon program, to be initiated 1n the near future> to be appropr1ate and beneffcfal.
X.7 Conclusions The HAC staff concluded that the licensee's
- programs, developed and implemented in response to License Condition 2.C.(ll) Items 2 and 3, are acceptable.
The licensee's program provides assurance that close proximity rigid restraints will share imposed loads and that snubbers located close to another support will function.
The programs and the corrective. actions taken by the licensee are adequate for full power operation.
REFERENCES X. 1 I. T. Yfn, Ofab1o Canyon l Draft Investfgatfon/Inspectfon
- Report, Rey, 3, Harch 29, 1984 (Prelfmfnary}.
X,2 J.
Q. Schuyler Letter to 0, G. Efsenhut, Qocket No. 50-275, OL-OPR-76, Diablo Canyon Unit 1, License Condftfon 2.C.ll " Final Report, PG5K Letter OCL-84-203, June 1, 1984.
X.3 J. 0. Schuy1er Letter to 0.
G. Bseshut, Docket No. 50-275, OL-OPR-76, Diablo Canyon Unit l, License Condftfon 2.C.(ll)-Final Report, PG8E Latter OCL-&4-2W ~>di H84.
10
~
~
O.
Licen'se Condition 2.C 11
, Item 4 "PG&E shall identify all pipe supports for which thermal gaps have been specifically included in the piping thermal analyses.
For these cases the licensee shall develop a program for periodic inservice inspection to assure that these gaps are maintained throughout the operating life of the plant.
PG&E shall submit to the NRC staff a report containing the gap monitoring program.
l.
Introduction Section 4 of the enclosure to the June 7, 1984 PG&E letter notes that at the time of that submittal in the thermal analyses
'of 11 piping systems, PG&E has taken credit for 37 field measured clearances or gaps for 28 supports.
These gaps are in no cases larger than the field construction tolerances.
The gaps have been modeled in piping thermal analyses to provide lower support or anchor design loadings or lower pipe stresses than would be obtained if credit were not taken for the gaps in the analyses.
The analyses included situations where the gaps would not be expected to be fully closed on piping thermal expansion as well as situations where the gaps are expected to fully close during the heatup of the piping.
Enclosure 4 of PG&E letter dated April 27, 1984 indicated that a
(2) total of 4 gaps had been modeled in 2 large bore piping analyses and 43 gaps have been modeled in 15 small bore piping analyses.
Section 4 of the enclosure to PG&E letter dated June 7, 1981 indicated that the two large bore piping systems have been rean-alyzed with the gaps removed from the models.
All pipe stresses, pipe support loads, and nozzle loads have been shown to remain within allowables.
Additional small bore piping systems have been reanalyzed with the gaps removed and similar results were obtained.
This is the reason for the difference in numbers from the more recent submittal of June 7, 1984.
This subject area has also been discussed in SSER 22 under allegation 88.
In that SSER the staff concluded that the modeling of thermal gaps in piping with service below 200'F was acceptable without a gap monitoring program since those thermal movements are small and not expected to be of concern.
The staff also concluded that the practice of modeling gaps in piping thermal analyses for piping with service conditions above 200'F is acceptable only if these gap configurations can be shown to be present and repeatable throughout the life of the plant.
Enclosure 4 of PG8 E letter dated April 27, 1984 proposed an inser-vice inspection (ISI) program for monitoring thermal gaps.
The proposed program would require monitoring of gaps for piping with service above 200'F (i.e., piping subjected to temperatures above 200'F, or piping attached to lines subjected to temperatures above 200'F).
The ISI program would require these gaps to be measured during each refueling outage and any exception to previously established minimum gap requirements to be reported to Engineering for resolution.
3.
NRC Review An Item 4 review team of NRC staff and consultants made a site visit which took place Hay 21 through Hay 25, 1984.
Ouring this site visit discussions were held to review typical cases for which gaps were modeled, the actual analyses and related documentation, and the PGSE proposed inservice inspection program.
The Item 4 review team concluded that the proposed program was not adequate for the piping with service above 200'F during normal and upset conditions.
The proposed program would not provide confirmatory information on the support gaps when the piping is in the hot configuration.
Furthermore, it would be undesirable because of ALARA considerations to obtain the hot condition confirmatory information required to make such a monitoring program acceptable.
To resolve this concern, PGSE proposed to undertake a program to qualify the piping system supports for loads obtained with the gaps ignored in the thermal analyses.
This program will be undertaken only for piping with service above 200'F during normal and upset conditions.
The program will be completed by the end of the first
refueling outage and may result in some support modifications.
This commitment was provided in the PG8E letter dated June 7, 1984.
Thermal gaps in piping with service above 200'F only during emer-y ~
gency and faulted conditions has been analyzed and meet criteria.
These lines will experience a very low number of thermal cycles, if
- any, and this would not be subject to repeatability throughout the life of the plant.
Therefore, the staff agrees that this piping need not be included in the program to reanalyze without the thermal gaps.
The piping system with thermal gaps and service above 200'F during normal and upset conditions have been analyzed using as-built gaps and have been shown to meet criteria.
These systems have also been heated up and cooled down through hot functional testing without any adverse affects.
These systems have been included in piping hot walkdowns and found to behave reasonably close to predicted behavior.
Ouring one fuel cycle the number of additional thermal cycles for these systems would be small and the as-built gaps would not be expected to change appreciably.
Therefore, the staff finds acceptable the proposed program to remove gaps from the thermal analyses of these piping systems and requalify the piping equipment nozzles and supports by the end of the first refueling outage.
4.
Conclusions PG&E have identified all pipe supports for which thermal gaps have been specifically included in the piping thermal analyses.
Section 4 of the report identified as r'eference (1) includes a commitment to undertake a program to qualify the piping system supports for loads obtained with the gaps ignored in the thermal analyses.
PG&E also comitted to complete this program by the end of the first refueling outage.
Based on the review as discussed in Section 3
above; the staff has concluded that the terms of license condition 2.C.(11), item 4 have been satisfactorily met.
5.
References (1)
PG&E License Condition 2.C.(11) Final Report, Section 4, Thermal Gap Modeling, received with letter from J. 0. Schuyler (PG&E) to D. G. Eisenhut (NRC) dated June 7, 1984.
(2)
PG&E Letter dated April 27, 1984 from J. 0. Schuyler (PG&E) to Darrell G. Eisenhut (NRC), on subject of Docket No. 50-275, DL-DPR-76, Diablo Canyon Unit 1, License Condition 2.C.(ll).
(3)
NUREG-0675, Supplement No. 22, Safety Evaluation Report related to the operation of Diablo Canyon Nuclear Power Plant, Units 1 and 2, March, 1984.
I 1
I
~
~
~ wa ~
License Condition 2.C.
11
, Item 5 "PGSE shall provide to the NRC the procedures and schedules for the hot walkdowns of the main steam system piping.
PGSE shall document the main steam hot walkdown results in a report to the NRC Staff."
l.
Introduction Hot walkdowns consist of visual examination of piping systems at elevated temperatures to assure that the piping systems are restrained only as.designed.
In addition, displacement measurements at both cold and hot piping temperatures are made at selected points.
These cold-to-hot measured displacements are then compared with calculated cold-to-hot displacements.
The objective is to assure that calculations of piping pressure-boundary
- stresses, support loads and nozzle loads are reasonably accurate.
Comparisons of calculated and measured displacements are often helpful in finding unintended piping system. restraints.
Enclosure 5 of PG8E letter dated April 27, 1984 provided Procedures P-36, "Walkdown of Piping During Initial Plant Heatup" and P-38, "Walkdown of Piping During Power Ascension" Review of the procedures by staff raised several questions concerning the details of implementing these procedures as applied specifically to main steam lines and, more generally, to all lines covered by Procedures P-36 and P-38.
These questions were discussed at a meeting with PG5E at Bethesda on May 9, 1984 at which time arrangements were made or a site visit which took place May 21-25, 1984.
)l I
I
~,
I
~
Several generic aspects of piping system walkdowns are discussed in paragraphs 2,
3 and 4.
An Item 5 review team of. NRC staff and consultants observed walkdowns of portions of the residual heat removal system (RHR)* discussed in paragraph 5.
They also observed walkdowns of portions of main steam piping discussed in paragraph 6.
Conclusions on Licensing Condition 2.C.(11),
Item 5, based on these generic and specific reviews, are given in paragraph 8.
2.
Assurance of Correct Dimensional Correlations During piping system walkdowns, it is essential that the calculated displacements be translated into corresponding directions at the measurement points; e.g.,
movement north or south for a cold-to-hot piping system temperature change.
The staff review determined that PGSE has taken appropriate steps to assure that calculated displacements are appropriately identified as to direction for correlation with measured displacements.
- The Review Group on Diablo Canyon Issues suggested staff inspect>on (5) of the mainsteam and main feedwater hot walkdown.
However, obtaining feedwater operational temperatures is not possible under the low power license.
PG&E agreed to conduct another walkdown of RHR for the NRC Item ) review team.
Main feedwater hot walkdown is included as part of P-38 during power ascension.
l I
I I
3.
Tem erature or Power Level Plateaus During heatup and power ascension, it is prudent to check piping systems at several ascending steps to assure that damage will not occur if, for example, some unintended restraint is acting on the piping system.
Startup procedures, including hot walkdowns of piping, are contained in PGSE Test Procedure No. 40, "Startup Program Master Document" This procedure covers both heatup and power ascension tests.
During heatup tests, plateaus have been established at reactor coolant system (RCS) temperatures of 250'F, 340'F, 450'F and 547'F.
At each RCS temperature
- plateau, Procedure No. 40 includes the check-off item:
"PTGC has successfully completed the piping walkdown."
PTGC stands for Plant Team, General Construction.
This must be initialed and dated by the Shift Startup Engineer before the step to the next higher temperature plateau can be started.
In applications to date, the Shift Startup Engineer has obtained approval from the Onsite Project Engineer Group (OPEG) acting for PTGC.
The piping systems that are included in the heatup walkdowns are identified in Appendix 8 of P-36 (2)
-This aspect is discussed in 5.4.1 of reference 7.
It should be recognized that the temperature plateaus are in terms of RCS temperatures.
However, main steam piping hot conditions outside containment can be reasonably well-controlled only when RCS temperatures are about 500'F.
The walkdown of main steam outside containment is not included in Appendix 8 of P-36 because (2) reactor heat, before ascension above 5X power, was intended to be removed by atmospheric dump valves.
These dump valves are located upstream of most of the main steam piping outside containment.
Walkdown of main steam piping outside containment before ascension above 5% power is included in P-38 as a special case:
"In (3)
- addition, a walkdown of the main steam piping outside containment will be performed before ascension above 5X power with NRC participation."
The results of this walkdown.are discussed in paragraph (6) herein.
Procedure 40, for Power Ascension, provides steps of power levels at 30%, 50K, 75>> and 100%.
At each power plateau, Procedure 40 includes the check off item:
"Confirm through PTGC Mechanical Department that walkdown of piping systems has been satisfactorily completed to allow power escalation to X5 RTP."
X is the power plateau and RTP is reactor thermal power.
The staff review determined that PGSE has exercised appropriate controls to avoid damage to piping systems and supports during heatup and will exercise similar controls during power ascension.
4.
Records of Previous Walkdowns PGKE has established a record of heatup walkdowns in the form of "Heatup Walkdown Packages."
There are 47 such packages, identified in Appendix 8 of P-36 In addition, there is a package for mainsteam piping outside containment.
Each of these packages describes the results of measurements and visual examination for the piping included in the package.
A total of 320 measurement points were used on Packages 1-44.
Measurements at these points have been taken of various heatup temperature plateaus and, in some cases, have been retaken during subsequent heatups.
The total number of measurements is in the, order of 1500.
A plot made of the last set of 320 readings at RCS temperature of 547'F showed how the differences between calculated and measured displa'cements compare with the acceptance criteria described by Appendix D of P-36 All except 8 of the 320 measurements met the criteria.
The "8-outside-criteria" are discussed later herein.
The measurements for Packages 45-47 (Diesel exhaust piping) were not completed as of 5/25/84.
They will entail another 10 measurement points.
Measurements, on main steam are discussed in paragraph 6 herein.
Yisual examinations during walkdowns were guided by comparisons of
" measured with calculated displacements and led to the identification and correction of approximately 135 unintended restraints; 80 in Packages 1-47; 56 in mainsteam outside containment.
The large displacements of main steam lines (up to 7") led to the relatively large number of unintended restraints in mainsteam systems.
The "8-Outside-Criteria" measurement points previously referred to were on the following five lines:
1.
Steam Generator 1, Blowdown Inside Containment Line No. 1040-2 1/2 2.
Steam Generator 2, Blowdown Inside Containment Line No. 1041-2 1/2 3.
Reactor Coolant Pump 2, Seal Mater Injection Bypass Line No. 1499<< 3/4 4.
& Safety Injection to Loops 1
& 2 Hot Legs Line No. 2576-8 5.
Component Coolant Mater, Thermal Barrier Return From Reactor Coolant Pumps 3 and 4 Line No. 2342-3.
Four of the eight discrepant date points are associated with the Steam Generator 1 and 2 Blowdown Lines.
The discrepancies were due to interference between pipe clamps which move towards each other during heatup.
Prior to this audit, PG&E performed analyses of these two lines which considered the effects of thermal restraint induced by the interferences.
The analyses indicated that stresses
in the pipe lines and their supports would still satisfy the appropriate pipe and support code stress allowables and thus were acceptable.
The Reactor Coolant Pump 2 Seal Water Injection Bypass Line had one of the eight discrepant data points.
This line was originally analyzed at 100'F, with a 70'F ambient temperature, and thermal anchor displacements from the Reactor Coolant Pump at 547'F.
The discrepant data points is at a considerable distance from the pump and effects of pump displacements at the data point location would be expected to be minimal.
The thermal movement measured at this point will therefore depend on the range of temperature experienced by the pipe only.
The actual line and building ambient temperature was observed by PGSE to be 80 to 90'F in the location of this data point.
PG8E performed an analysis with this'ctual ambient temperature and showed the thermal movement at this data point to now be within the acceptance criteria.
The Residual Heat Removal and Safety Injection Line is a Balance of Plant Line that has been analyzed by Westinghouse.
The two discrepant data points in this line were transmitted to Westinghouse for resolution.
Westinghouse concluded that the normal friction in the sliding type pipe supports was the reason that these points did not respond as originally predicted.
Westinghouse made an additional thermal computer analysis with the actual measured displacements as additional boundary conditions, superimposed with the thermal growth of the piping system., This analysis showed an increase in pipe and support stresses, but did not result in any pipe or support stresses exceeding their code allowable stresses and thus were acceptable.
The Component Coolant Water Return Line had one of the eight discrepant data points.
PG8E determined that the normal friction of the sliding type supports in this location was the reason for this discrepant data point.,
PG8E made a new computer model which reflected the additional frictional forces and found close agreement with the measured displacements at all reference points, but they also found that the pipe stresses exceeded the code I
allowables.
Subsequently, PG&E modified those appropriate sliding type (friction supports) to sway struts to eliminate the friction forces and to reduce the pipe stresses to be within code allowables.
In conclusion, PG8E has used reasonable engineering approaches to resolve the "8-outside-criteria" measurement points through:
(I)
Additional analysis to determine the possible causes and effects of these discrepancies on the piping and support systems and (2)
Support redesign to ensure that the pipe and support stresses will not exceed their code allowables.
Our audit provided assurance that PG8E has been diligent in assuring that piping systems covered by P-36 are behaving in (2) reasonable agreement with calculated behavior and that a reasonable effort has been made to remove unintended restraints.
Ouring power ascension, P-38 will provide additional checks on (3) the behavior of the piping systems covered therein.
5.
Residual Heat Removal RHR Walkdown Prior to the Item-5 review team site visit, from May 21, 1984 through May 25, 1984, several walkdowns had been conducted on RHR piping.
Heatup Walkdown Package No. 40 is directly relevant to the staff site audit.
This package was prepared while conducting the RHR piping walkdowns during initial heatup under Procedure P-36.
Package 40 identifies 24 measurement points and gives the results of those measurements and comparisons with calculated displacements.
Package 40 includes 25 Heatup Walkdown Problem Reports, identifying 12 interference problems that were corrected, 2 out-of-criteria measurements (later resolved by additional measurements) and 11 other miscellaneous problems such as instrument tubing of inadequate flexibility and a twisted support.
Item-5 review team examined the basis used for selecting the 24 measurement points; these measurement points consisted of locations where measurements could be conveniently made for example using snubber or spring can travel, and where the hot-to-cold displacement was calculated to be relatively large.
In the RHR walkdowns, measurements were taken at points with calculated displacements ranging from 0.2 to 1.0", the largest calculated
'displacement at any point on the piping.
The number of measurement points chosen was regarded by the NRC audit team to be of a minimal size for their intended purposes.
However, after a careful review of the piping configuration and the predicted motions it was concluded that the number of measurement points was sufficient to validate piping behavior and detect unintended restraints that would impede piping system thermal growth.
The review also determined that the methods for determining the actual deflections was acceptable.
Item-5 review team observed walkdowns of the RHR system outside containment from Penetration 27, through RHR pumps 1-1 and 1-2, and continuing as far as RHR heat exchangers l-l and 1-2.
Cold measurements were taken on 5/21/84 and hot measurements were recorded on 5/24/84.
There were 12 measurement points in this walkdown, including one not included in earlier walkdowns discussed in paragraph 4.
Visual observations of the Item-5 review team during the walkdowns did not indicate any unintended interferences, nor were any noted by the PGKE staff members during the walkdowns (leakages were observed at a flanged joint and at the RHR 1-2 pump casing.)
The measurements taken during the May 21, 1984 walkdowns agreed with
calculated displacements somewhat more closely for several points than did those from the previous walkdown made in November 1983.
All measured displacements were within the PGSE acceptance criteria, Appendix D of P-36 The RHR walkdown is also discussed in reference (7).
The review concluded that PG8E has been diligent in assuring that
-the RHR piping systems are behaving in reasonable agreement with calculated behavior and that a reasonable effort has been made to remove unintended restraints.
6.
Hain Steam (MS Malkdown Heatup walkdowns had been conducted on mainsteam piping prior to the Item-5 review team site visit of Hay 21, 1984 through Hay 25, 1984.
The results of these walkdowns for the mainsteam piping inside containment are contained in Heatup Malkdown Packages 5
through 8.
Packages.5-8 identify 2 measurement points for each steam generator outlet line and gives the results of measured deflections and comparisons of measured vs. calculated deflections.
Additional heatup walkdown packages were prepared for the piping outside containment.
These packages focus on interference problems and measurements were not taken for the mainsteam piping outside containment.
These packages were all prepared while conducting the piping walkdowns during initial heatup under Procedure P-36.
Each of the Heatup Walkdown Packages 5-8 included one Heatup Walkdown Problem Report (HWPR) except Package no.
7 which contained two.
These HWPR's were related to deflections which were measured at temperatures less than the maximum heatup temperature and which were outside criteria.
The problems were later resolved at higher temperatures when the measured deflections were within criteria.
These problems were attributed to support frictional effects.
The packages for mainsteam outside containment included 56 HWPR's.
These problems related to interference problems that were corrected and miscellaneous other problems, such as inadequate flexibilityof instrument tubing and buckling of a support.
The Item 5 review team reviewed the power ascension walkdown procedures that were applicable to heatup walkdowns of the mainsteam piping being conducted during the NRC site visit.
The review team examined the basis for the selection of the 7 measuring points proposed for each of the mainsteam lines.
Five of the seven points were located outside containment and two inside containment.
The review indicated that although the number of measuring points selected was minimal, they were located such that discrepancies between measured and calculated deflections at any one of their locations would suffice to indicate the presence of unigtended thermal restraints.
It was concluded, therefore, that the number of points selected was acceptable.
The review also found the methods for determining the actual deflections to be acceptable.
Calculated deflections were in the range of 0.2 in.-
6.8 in.
The Item 5 review team participated in walkdowns of all four mainsteam lines from the four steam generator outlets to the anchors at the seismic to non-seismic classification change.
All 4 lines were observed visually; however, thermal measurements were
'I taken on the two mainsteam lines from steam generators 1 and 3.
The lines from steam generators 1 and 3 are configured similarly to the lines from steam generators 2 and 4 and their deflections during heatup are similar.
The data generated during the walkdown were documented in special Power Ascension Walkdown packages 5 and 17 for the mainsteam lines from steam generator 1 inside and outside containment, respectively, and packages 7 and 19 for the mainsteam lines from steam generator 3 inside and outside containment, respectively.
Five Power Ascension Walkdown Problem Reports (PAWR) were included in Power Ascension Package No.
17 and four in Package No. 19.
The problems included:
(1) one outside of criteria measured deflection on each line, (2) loss of data due to removal of a measuring scale during painting of the support, (3) interference with temporary scaffolding erected for the walkdown, and (4) miscellaneous other
- problems, such as valve leakage and wrong support identification.
Additionally, an unintended contact was observed between an abandoned stanchion on mainstream line 3 (from steam generator 3) and a structural column.
This interference only existed on full heatup.
The data in Power Ascension Package Nos.
5 and 7 indicated that the mainsteam piping inside containment was responding during thermal cycling within the acceptance criteria.
As indicated above there was one data point. on each line outside containment that was outside the acceptance criteria.
Accordingly additional thermal stress analyses were performed by Westinghouse with the actual measured displacements as additional boundary conditions, superimposed with the thermal growth of the piping system.
The analyses showed that stresses in piping, pipe supports and flued heads were within their respective code allowables.
The mainsteam walkdown is also discussed in reference (7).
Our audit of the mainsteam walkdowns indicate that PG8E has been diligent in assuring that the mainsteam piping systems are behaving in reasonable agreement with calculated behavior'and that a
reasonable effort has been made to remove unintended restraints.
7.
Re ort on Mainsteam Walkdown Results A part of License Condition 2.c(ll), Item 5 states:
"PG5E shall document the main steam hot walkdown results in a report to the NRC Staff."
Section 5 of the report identified as reference (7) covers more than the mainsteam hot walkdown results.
NRC staff have reviewed Section 5 of the PG5E report, including those portions on mainsteam hot walkdown results and conclude that it is acceptable as the report to the NRC staff on the mainsteam hot walkdown results.
8.
Conclusions In conjunction with the review of the Mainsteam Walkdown the staff also reviewed the general aspects of the engineering techniques used by PG8E to perform hot piping walkdowns of the systems covered by Procedure P-36.
The evaluation of these aspects is covered in paragraphs 2,
3 and 4 of this section.
In addition, the staff observed a walkdown of a portion of the RHR system outside containment.
The staff evaluation of this walkdown is covered by paragraph 5 of this section.
Paragraphs 6 and 7 cover the main steam walkdown and the report on the main steam walkdown results which was the specific subject matter of the license condition.
Our review concluded that PG&E used acceptable engineering techniques in conducting piping hot walkdowns and that the RHR and main steam walkdowns observed by the staff resulted in piping system thermal movements in reasonable agreement with calculated movements.
Based on the above the staff has concluded that the terms of the license condition 2.C.(11),
item 5 have been satisfactorily met.
9.
References (1)
PG&E Letter Dated April 27, 1984 from J. 0. Schuyler (PG&E) to Oarrell G. Eisenhut (NRC). on Subject of Docket No. 50-275, OL-OPR-76, Diablo Canyon Unit 1, License Condition 2.c.(11).
(2)
PG&E, Mechanical and Nuclear Engineering, Diablo Canyon Unit 1, Walkdown of Piping During Initial Heatup, Procedure P-36, Revision 2, 4/26/84.
(3) 'G&E, Mechanical and Nuclear Engineering, Diablo Canyon Unit 1, Walkdown of Piping During Power Ascension, Procedure P-38, Revision 1, 4/26/84.
(4)
Transcript of Meeting with Staff and Utility on Diablo Canyon,
- Bethesda, Maryland, May 9, 1984.
(5)
Richard H. Vollmer to.Harold R. Denton, April 12, 1984, on Subject of Report of the Review Group on Diablo Canyon Piping Issues.
(6)
PG&E Station Construction Department, Diablo Canyon Project, Unit 1, Test Procedure No. 40, "Startup Program Master Document,"
Rev.
5, 4/30/84.
(7)
PG&E License Condition 2.C.(11) Final Report, Section 5; Hot Piping Walkdown, received with letter from J. 0. Schuyler (PG&E) to O.
G.
Eisenhut (NRC) dated June 7, 1984.
X.O LICENSE CONDITION 2.C. (11)/ITEN 6 PGSE shall conduct a review of the "Pipe Support Design Tolerance Clarification" (PSDTC)
Program and the "Diablo Problem" (DP) System activi-ties.
The review shall include specific identification of the following:
(a)
Support changes which deviated from the defined PSDTC Program scope (b)
Any significant deviations between as-built and design configurations stemming from the PSDTC or DP activities (c)
Any unresolved matters identified by the DP system.
The purpose of this review is to ensure that all design changes and modifications have been resolved and documented in an appropriate manner.
Upon completion, PG8E shall submit a report to the NRC staff documenting the results of this review.
X. I INTRODUCTION The Pipe Support Design Tolerance Clarification (PSDTC)
Program and Diablo Problem (DP) System are described and evaluated based on submittals provided by the licensee and the understanding of the staff and their consultants on these activities.
Numerous meetings with licensee personnel, discussions with allegers, and audit of the PSDTC and DP Programs by the NRC staff and their consultants provided the bases for this understanding and for evaluation of these activities.
While the PSDTC Program interfaces with the DP System, this SSER addresses each separately for the sake of clarity.
The licensee defined scope and their implementation of each program is
evaluated to assess compliance with program intent and the effectiveness of each process in insuring that the installed pipe support designs have been
,properly analyzed and documented.
X.2 PIPE SUPPORT DESIGN TOLERANCE CLARIFICATION,
'ROGRAN (PSDTC)
X.2.I, Background The licensee established,a special team of pipe support engineers
'n January 1983.
Their assignmeqt, then and now, consists of direct engineering liaison with General Construction resident engineers and Pullman Power Products craft personnel for the purpose of providing expeditious resolution of minor construction difficulties in the installation of large and small bore pipe supports.
This group of,engineers had the authority to resolve construction problems in the field based on their best engineering judgement and knowledge of applicable Diablo Canyon design criteria.
The licensee described the PSDTC program in Reference X-I with supplemental information provided by References X-2, X-3, and X-4.
OPEG Guide 4, Rev.
- 1. dated January 7,
- 1983, and titled "Guide for Issue of Pipe Support guick Fix Design Changes" initially provided the control and defined the responsibilities and authority for administration of the "guick Fix" program.
This guide was superseded by Project Engineer's Instruction (PEI) 12 on March ll, 1983, which defines the Pipe Support Design Tolerance Clarification (PSDTC) Program.
The practices defined by these two documents are based upon identical philosophy. and intent.
As provided in PEI-12, field construction problems are defined as pipe support installation problems, which can not be resolved using the construction tolerances explicitly stated in Pullman Power Products document ESD-223, "Installation and Inspection of Pipe Supports".
Construc-tion tolerances contained in ESD-223 were those that could be applied
'1 h,
~'
to any pipe"support in the plant without additional engineering justification.
s Changes*beyond those tolerances are permitted but must be evaluated against the criteria contained in Diablo Canyon Design Criteria Memorandum (DCM)
M-9, "Guidelines on Design of Class I Pipe Supports and Restraints."
For Unit 1, field construction problems were referred to PSDTC team engineers who. based on their engineering judgment and knowledge of OCM M-9, would, on a case-by-case
- basis, determine whether use of expanded tolerance limits could be authorized to resolve the construction problem while maintaining an acceptable support design.
Where field resolutions could be made, in the judgment of the PSDTC team engineer, they were documented on individual PSDTC forms (See Figure X-g).
Field construction
- problems, which 'could not be resolved without a design change in the judgment of the pSDTC engineer, were returned to General Construction for formal referral to other project procedures.
When a
PSDTC form was completed, a copy was attached to the pipe support design package and was treated exactly like the original design package in order to assure that standard quality control procedures were applied to all work accomplished by General Construction.
Upon completion of construction of the support, the complete as-built package, including any PSDTC forms associated with that support, was forwarded by Construction to Engineering for final acceptance in accordance with project engineering procedures.
The as-built acceptance process involved review of the revised support design and performance of necessary calculations for qualification of the design.
Nhere qualification could not be shown, a
new design was prepared and issued for Construction.
The PSDTC process just described is illustrated by Figure X-2 as provided by the licensee in Reference X-2.
FIGURE X-l.
PIPE SUPPORT DESIGH TOLERANCE CLARIFICATION FORM SEQUENCE NUMBER (UNIT + NUMBER)
SVNECT (USE SUPPORT NUMBER)
LOCATION (AREA AND ELEYATIOH)
CLASS (I
OR II)
DESCRIPTIOH: '.
Describe problem clearly.
2.
Use sketches in this space or in attachments.
3.
Clearly show proposed changes.
4.
Attachments may include marked up copy of support drawings.
REFERENCE DRAMING (USE DCN NUMBER PLUS AHY OTHER APPLICABLE)
ATTACHMENTS YES NO PAGES (INC. THIS SHEET)
AREA ENGINEER:
CONSTRUCTION MAY PROCEED (PIPE SUPPORT AREA EHGINEER SIGNATURE)
CONSTRUCTION D.P.
REQ'D (PIPE SUPPORT AREA ENGINEER SIGNATURE)"
CONTRACTOR RECEIPT (CONTRACTOR'S 4C OR OTHER REP.)
DATE (RECEIPT DATE) 0008Q/0060P
ESO 223 FIGURE X-2.
FLOW CHART FOR PSDTC Pf I Il I
I GfNERAL I ENGINEERING MANUAL I
I RECEIPT. LOG 6I DISTRIBUTE PI-I1 DCN e
ISSUED PRE INSPECTION P.t.t.
CONSTRUCT IGNI Ilc. REVlfW t.t P.
ELA. RfVIEW PP.P.
PPP DISCREPANCY REPORT P P.P.
PREPARES PSDTC PSDTC REVIEWED BY AREA ENG CONSTRUCTION AUTHORIZED Tn PRIICEED CONSTRUCTION NOT AUTHORIZED TO PROCEED I
Il li GfNERAL CONST.
DIABLOPROBLEM IDPI ISSUED Pl-1 REFER TO DPFLOWCHART FOR MORE DETAIL (FlGURE X-3)
I RECEIPT BI I
DISPOSITION a
PE I-1 I
.J AS BUILT-P.P.P-
~AR fJgfg-RfDLININ0 ANO COPIES OF PSOTC'S.
PI~ABOA -IHCORIOAATION OF ALLCHANGES-PSDTC'S LISTED ON DRAWINGS.
LOG AND TRANSMIT PI-I1 RDECT ASBUILT I. LOGGING
- 2. EVALUATION
- 3. INCORPORATIO INTO AS BUILT DRAWING P 16 ACCEPT OCN I
CLOSURE I
P.P.P. - Pullman Power Products This chart is from Reference X-2.
The procedures used or related to this program in addition to PEI-12 and ESD 223 are:
o P-10, "OPEG Small Bore Piping and Hanger Review Procedure"
~
I-37, "Instructions for Incorporation of Field Correction Transmittals"
~
I-40, "Instructions for Disposition of As-Builts Associated with Design Change Notices"
~
PI-17, "Document Control operating Instructions" e
P-16, "Procedure for the Preparation, Review, Approval, Update, and Issue of Pipe Support Detail Drawings".
P-16 supercedes I-37 and I-40 as of April 7, 1984.
In summary, the licensee defined and implemented a program to allow minor pipe support changes to be made by qualified field engineers.
The PSDTC process was initially controlled by a guide and later by formal procedures which provided a mechanism for insuring field changes were evaluated by appropriate Engineering personnel.
Some 15,000 field changes or corrections have been made as part of the PSDTC Program.
X.2.2 Formulation of License Condition In response to allegations concerning quality assurance and quality control as related to Diablo Canyon Project design control and construction practices, the NRC staff commenced its review of licensee programs with a series of inspection trips, Ref. X-5.
In the case of the PSDTC program.
governing procedures and implementation of this program were reviewed with the licensee and its contractor personnel'his effort included review of the following:
e DCP OPEG document titled "Guide for Issue of Pipe Support guick Fix Design Changes",
Rev. I, dated January 7,
1983
X.. ~,
~
I o
DCP Instruction No.
fications", Rev.
1, 12, "Pipe Support Design Tolerance Clari-dated August 5, 1983 o
TC 1-11202 for pipe support 74-33R and analysis file e
TC 1-11306 for pipe support 322-7R and analysis file e
TC 1-11369 for pipe support 18-7R and analysis file o
TC 1-14057 for pipe support 57-15.
The staff concluded, based on this audit, that "there appeared to be a breakdown in the licensee's gA program for site design change control."
Subsequent review of this program was accomplished by an NRC review group formed to address this and other Diablo Canyon piping related issues.
This group agreed that this issue should not preclude criticality and operation at low power and did not, by itself, demonstrate a generic breakdown of quality assurance or design and construction effectiveness.
However, sufficient concern existed within the review group to establish Item 6 of License Condition 2.C.( 11) as ft pertains to the PSDTC Program.
X.2.3 Licensee Review of PSDTC Program The licensee has performed a two-stage review involving more than 2000 of the 15,000 PSDTC's written since the inception of this program.
During the initial review phase, 1100 small and large bore pipe support PSDTC's wer e reviewed to identify those containing siqnificant design changes.
This review resulted in the identification of PSDTC's for seven small bore and twenty large bore supports which had significant design changes and which would receive a further, more detailed review.
The licensee then reviewed an additional 1000 PSDTC's selected
,from three different time periods for the purpose of categorizing the nature and design significance of each.
PSDTC's were selected from the months of April, July, and October 1983.
This represented the beginning, middle, and recent activity on this program.
The design significance was defined as changes which:
(a)
Reduced the support capacity or (b)
Caused the calculations to be revised.
The results of this second sample are summarized in Table X-1
- Also, an additional thirteen PSDTC's written against small bore pipe supports were selected at random for a fur ther more detailed review.
This raised to 20 the number of small bore PSDTC's which would be examined in detail.
Following these reviews, the forty PSDTC's identified for further review were examined in detail to verify that:
(a)
Changes made within the PSDTC program were reflected in the as-built drawing, and (b)
Appropriate calculations or engineering disposition was made to qualify the change as part of the as-built acceptance procedure.
The licensee
- reported, Reference X-2, that all forty changes had been incorporated in the drawings and complied with appropriate design criteria.
TABLE X-1.
SUMMARY
OF LICENSEE REVIEW'FINDINGS*
PSDTCs Mod Type Category 1.
Significant Structural Redesign 2.
Significant Base Plate Modification 3.
Weld Changes 4.
Clarify Design Intent (location plan, etc.)
5.
Minor Structural Changes (coping, substituting larger member, etc.)
6.
Location 7.
Adjacent Anchor Bolt 8.
Disposition to DP Process 9.
Supersede/Yoid Large Bore 789. PSDTC's 80%
13%
16%
18%
35%
2%
4%
13%
Small Bore 193 PSDTC's 20%
13%
13%
16%
10%
35%
2%
Total 982 PSDTC's 100%
13%
15%
18'%5%
13%
- The total percentage of modification types exceeds 100% because some PSDTC's involved more than one type of modification.
10 X.2.4 NRC Staff Review The NRC staff review addressed both the scope and implementation of the PSDTC Program.
This effort was initiated with review of the Reference X-3 and included review of:
(a)
Applicable procedures, including required interfaces, to develop an understanding of the program scope and intent (b)
Verbal description of the PSDTC process by the licensee using Figure X-2 (c)
Specific PSOTC's, Table X-2 (d)
Corresponding support calculations (e)
Selected supports as installed in the plant (f)
Interviewed a
PSDTC engineer who participated in the licensee's review program (g)
Review of the licensee's PSDTC review program.
The PSDTC program, Figure X-2, review by the NRC staff addressed the pro-cedural aspects and the nature of program implementation.
As previously
- noted, the licensee established the PSDTC program to provide a mechanism for addressing minor field alterations to pipe support configurations during construction.
Specifically, the program allowed minor revisions to support designs when the tolerances in Pullman Power Products procedures ESO 223 were exceeded, but within H-'9'.
For such cases, a
PSDTC Program engineer could authorize the change and permit construction to continue.
A block of PSDTC's, TC-1-10700 through
- 10800, was reviewed to assess their design significance and to verify the licensee's findings concerning the significance of design modifications made as part of this program.
The NRC staff reviewed the PSDTC's presented in Table X-2 which included:
(a)
Two previously reviewed by the NRC, Reference X-5 (b)
Those identified in allegations or in meeting with allegers (c)
Those reviewed by the licensee (d)
Randomly selected ones not previously addressed as part of other reviews.
11 TABLE X-2.
SUMMARY
OF PSDTC'S REVIEWED BY NRC STAFF PSDTC 3544 3545 3548 3554 3557 3582 3115 11355 11370 13271 13242 13241 13236 13224 13215 10706 13313 12667'3420+
3144 11255 11206 11213 PIPE SUPPORT 23S/34R 2163-2 73-37R 55S-11R 5-82R 85N-81R 73-71R 10-121SL 3-6V 92-102R 2-53R 85N-53A 57-15 1048-2SL 85N-53A 72-1A 2169-4 384-386R 55S-9R 92-107R 230-48R 97-54R PSDTC 11236 3181 3517 3220 3187 3236 3935 1311 11286 11297 13332 13347 9121 9430 13002 1148 13420 11306 11204 11205 PIPE SUPPORT 2-38SL 22-433 92-15 4-78SL 59N-16 1512-5 1033-15SL 2156-184 65N-125A 52-7A 72-50 98-82 2-47R 20-85R 384-386R 322-7R 55S-9R 57S-10R
12 This activity examined each PSDTC and the pipe support calculation.
The calculation package was reviewed to verify that the as-built support drawing was included, the analysis was revised to reflect the as-built condition, other disciplines were provided the opportunity to review any changes and concur with them, and to examine other PSDTC's written against the support.
Selected
- supports, Table X-3, were identified and examined as installed during a plant visit by members of the NRC staff and their con-I sultants.
Finally, the PSDTC Program was discussed with licensee personnel directly involved with the program. 'lso, the licensee 's review of the PSDTC Program was discussed at the plant site with one of the licensee review team leaders.
X.2.5 NRC Staff Findings The PSDTC Program was initiated and implemented by a "guide" rather than an approved procedure.
This guide was.later superceded by an approved instruction based on identical philosophy and intent.
Nevertheless, the PSDTC Program was implemented without an approved procedure.
Most of the PSDTC's reviewed were written to relocate anchor bolt holes or base plates, modify welds, or relocate a support.
- However, it was noted that some had, in essence, redesigned the entire support.
Therefore, the NRC staff concluded that the licensee did not comply with the intent of its procedures governing the Pipe Support Design Tolerance Clarification Program.
The term "minor revision" in PEI-12 is used to define the intended scope of the PSDTC program.
While this is a qualitative term, subject to interpretation, a number of examples reviewed by the staff involved much more than tolerance clarification.
Also, the licensee personnel
13 TABLE X-3.
PIPE SUPPORT INSTALLATIONS EXAMINED AT THE DIABLO CANYON PLANT PSDTC 9121 9430
" 13002 SUPPORT 2-47R 12667 Q 13420/
384/386R 13397 384/87R 12119 18-7R
'0 I
~
a ~
~
(
I I
reported that PSDTC engineers could authorize a modification if they believed with a high degree of confidence that it would be acceptable
'\\
to Engineering.
In spite of this condition, the NRC staff found the as-built support had been properly analyzed and complied with appropriate acceptance criteria.
The NRC staff finds that in response to Item 6a of License,Con-dition 2.C.(11), the licensee has through its submittal, Reference X-2, identified instances where support changes have deviated from the defined PSDTC program scope.
Also, the staff based on its review and a similar effort on the part of the licensee believes that, with respect to Item 6b of License Condition 2.C.( ll), no significant deviations exist between the as-built and current design configurations stemming from the PSDTC Program.
T~
~
15 X.3 DIABLO PROBLfH (DP)
PROGRAM X.3. 1
Background
At any construction site, many occasions arise when the construction engineers need to request additional information from project engineering in order to solve unforeseen problems.
These problems may be related to schedules, material availability (substitutions),
structural/component interferences, deviations from design specifications, minor design
- changes, etc.
To facilitate the handling of these requests and to minimize the upset in construction schedules, the Diablo Problem (DP) Program was established in early 1974.
The intent of the OP Program was to establish a process for project engineering to use when responding to construction engineering requests so that both the request and response would be properly and ex-peditiously handled.
A form, Figure X-3. is used to document, control, and resolve construction questions.
The current procedure for processing OP's is Instruction No. 7, referred to as PEI-7, Revision 3 dated Oct.
10, 1983.
A flow chart showing the processing steps for a OP is provided as Figure X-4.
Initially. the approved OP prepared by the construction engineer is sent to construction document control and project administration.
Project administration forwards the recorded and numbered OP to the appro-priate project engineering discipline where a response to the OP is prepared.
The project engineering approved response is sent to project administration, construction document control and to the construction supervisor who approved the original DP request.
When the construction supervisor approves the response, it will be given to the construction engineer for implementation
r,TTENTIOM:
PROBLEM DESCR IPTIOH:
16 F?GURE X-3.
PAClf 1C C45 AND ELECTR}C CO!PALY STATION CONSTRUCTION DEPART?'ENT 01AOLO CANTON PROJECT UNIT DIABLO PROBLEM CONTROL SHEET bP ORICIHATQR
~OOOO OAO1 lety Instructfon No. 7
/ttack-"ent A Page 1 o.f 1 SYSTEM axles<+
QCN/DFJ. REF 8 ~
~
R sponse Required Sy:
DATE PROBLKN RESPONSK Revfeml Sy.
lpproved Sy:
es ent n" neer Rev feted Bf:
fROMPSI)TC F LOW CHAR I FIGURE X-4.
OP FLOW CHART CONSTRUCTION PAOCEOUAE Pl 1 COPY Rf TURNED b DISTRIBUTED ON SITE COHSI LNtilHEIB fHCOUH)EBS PROIILfM IIIYI)HDPSD'TC SCOPE b PBE PARI S DP CONST DISCIPI IHE SUI'LBVISOH AfVlfWS b JIVPBOVES DP EXAMPIFS l Scil(DUII INfO 2 REDI,SIGN AEOD 3 UfNFAICTOLEBANCE
- 4. GEHFAIC DfslriN OR SPL CI>ICATII)H CLABIFICAI ION ADMIN PROC.
3)OI RETURN AECEIPT COPIES TO DIST. FOA INFO CONST OOCUMINI CON IAUL ASSIGNS NO UNIQUE 'IU IHf ENGR DISCIPLINf.
ENTF As IN SIAlUS AfPORI. 6 fORWARDS ISSUE STATUS PROJECT ADMIN RfCfIVFS. LI)GS. ON BEPOR1S. OVERDUE COMPUTE R LIS IINCi. d fUII WARDS ETC AfSPONSE, REPORTS.
PROJECT fNGIHfER IKST. PE I 2 3 I O'I COPlf S TO DIST. FOA INFO COGNIZANT OISCIPLIHf ENGINEER PBOVIDfS RESPONSE b DIRECTS DESIGN PREPARATION PAOJEC1 ADMINISTRATION UPDATES STA'IUS LOCi b fORWARDS 10 CONSTRUCTION IF DESIGN IS REDO..
PREPARE OCH IREFFR 10 ENGR. MANUAL PROC. 3.60N. PIPING PAOCS. FOR DESIGN, CALO.. As BUILT AfVIEWANO PROC.
P 28 FOR SUPPORTS COORDINATE WITHPIPE STRESS GROUP llfREOUIAEOI PAOCEOUAE P l6 COO AD INATE WITHCIVIL GAOUP llF REQUIAEO)
PAOCEOURE P 22 PI 1 ACCEPT-TO ENGR.
AEJECT-AEVISE TO REISSUE OP i
I I
I CONSTRUCTION DOCUMENT COHTAOL LOGS RESPONSE AECEIPT.
FORWARDS. 6 FILES CONSTRUCTION DISCIPLINE SUPERVISOR AEVIEWSb ACCEPTSOA REJECTS DfVIATIONfROM PROCEDURE DESIGN INFO CONTAINEDIN OP PIPING CONTAAC1OA RECEIVfS b ISSUES fOB CONS) RUCTION AEF ESD 223~EHG.
~
ICOVERS As BUILT PAOCESS ANO ENGINEERING i REFfA TO PSDIC FLOWCHAA'1 REVIEW AHP 4CCf PTANCf i
(FIGURE X-2)
This chart is from Reference X-2.
18 or, if the DP is related to piping, to the piping/piping support contractor.
At two decision points in this flow chart, it should be noted, either the cognizant project engineer or the construction engineering supervisor can make the decision to prepare a
DCN because either the request requires a redesign or the response contains significant design information.
Further the chart indicates that, with respect to piping, the contractor will include the DP in his as-built review and acceptance process.
The above discussion of the DP program procedure is a description of the licensee's response contained in their submittals, References X-2, X-3, and X-4.
That is, "The OP program was originally established to facilitate and expedite the handling of questions or requests made by the construction department to the engineering department.
DP's serve as a means to status and track such questions and requests.
This program was separate from and not to be used in lieu of the engineering design processes controlled by engineering manual procedures in accordance with guality Assurance Program requirements."
X.3.2 Formulation of License Condition The NRC inspection report (Page 78, Reference X-5) indicates that proper instructions to handle OP's did not exist prior to August 12, 1978.
On this date a Procedure Implementing Instruction, "Procedure for Hand'ling OP's" by D. Polly was issued.
Much later, DCP Instruction No. 7, "Processing Diablo Problems",
Rev. 0, was issued on August 10, 1982.
Revision 3 of Instruction No.
7 is the basis for the discussion in X.3. 1 above.
This lack of formal procedures throughout the OP Program prior to August 12 and the apparent lack of a definitive criterion for
19 what is and is not design information was reviewed prior to low power operation by the NRC review group formed to address this and other Diablo Canyon piping related issues.
As for the PSDTC program, this group was sufficiently concerned about the process to establish Item 6 of, License Condition 2.C(11) as it pertains to the DP Program, but agreed that this concern.should not preclude operation at low power.
X;3.3 Licensee Review of their Diablo Problem Program The licensee, in response to License Condition 2.C.(11), established a
OP review program.
The purpose of this program was, as for the PSDTC review program, to demonstrate that the OP process did not result in sig-nificant deviations between design configurations on OP's and as-built drawings with engineering approval.
Initially, the licensee review of OP's included only those DP's issued prior to August 10, 1982.
Later, after the transCribed meeting between the licensee and the NRC on May 9, 1984, the review was expanded to include all OP's issued for Unit 1 since the program inception in 1974.
The initial step of the review was to identify those DP's which contain design information related to piping and/or piping supports including both large bore and small bore piping.
Design information was defined as "any information which allows, or could be construed to allow, construc-tion to proceed with
( 1) work contrary to existing design drawings and specifications, or (2) work not shown on existing drawings or specifica-tions."
Those DP's that were found to contain design information were then reviewed in detail to determine if changes invoked by the DP were properly included in the as-built drawings and associated design analyses
20 I
calculations.
The licensee review of the OP Program was conducted in accordance'ith a written procedure which was provided to the staff on.
May 21, 1984.-
The licensee provided status reports on their review to the staff with their April 17, 1984, submittal (Reference X-2), again at the Hay 9, 1984, meeting and finally during the staff audit in San Francisco.
The licensee's final response to Item 6 License Condition 2.C( 11) is contained in their submittal of June 1,
1984 (Reference X-2).
From this report, the final results of the licensee review of the OP Program are summarized below:
(a) 3229 DP's were issued between December 7,
- 1973, and Hay 1,
1984 (b) 3120 OP's were reviewed per the review procedure (c) 127 OP's could not be located (d)
Df the 3120 OP's reviewed, 36% or 1133 DP's were related to piping/piping supports (e)
Of the 1133 OP's related to piping/piping supports, 16%
or 186 OP's transmitted design information (f) 160 of the 186 DP's containing design information were resolved by the information being included in as-built drawings and related design calculation files (g) 14 of the 186 DP's containing design information were super-ceded by a formal design change through the normal QA program (h)
The remaining 12 OP's associated with piping or piping supports were found to be non-seismic Category I or non-safety-related.
The licensee verbally reported that those OP's missing, Item (c),
were cancelled or superceded by other DP's.
0 21 X.3.4 NRC Staff Review Upon receipt of the licensee's submittal of April 27,
- 1984, the staff began its in-depth review of the OP Program.
guestions on this submittal were addressed at the transcribed meeting with the licensee on May 9, 1984.
An in-depth study of the licensee's review and the DP Program itself was conducted by the NRC staff and its consultants during an audit of this process.
This audit included the following:
(a)
A verbal walkthrough with the licensee of the OP process flow chart (Figure X-4) includinq the tie-in between<ween (b)
(c)
(d) the PSOTC and OP Programs A review of the OP Program review procedure Random review of the OP files for content and completeness Review of piping/piping support related DP's to confirm the licensee's conclusions that DP's were "piping related" and if so, did they transmit "design information".
(e)
Review piping support design calculation files, Table X-4, associated with the OP's where significant design information was transmitted to confirm that the calculations included the information.
(f)
Plant-site visit and inspection of piping supports associated with the documentation audit.
22 TABLE X-4.
PIPE SUPPORT CALCULATIONS REVIEMED FOR DP EVALUATION DP 3175-P 3174-P 3217-P 3158-P 2037-P 1896-P 3947-P 3197-P 3469-P Pi e
Su o~t 7.3-73R 1-31R 73-20R 384-123R 855-44R 52-7A 384-386R 13-3SL 4-35SL
23 Twenty-seven DP files containing design information were reviewed at the project engineering offices, nine of which were traced to the calcula-tional file to assure'ncorporation of the changes.
The content of each DP file was similar and consistent with the DP process procedure.
Each file included related PSDTC numbers, original and approved
- drawings, Design Change Notices, Field Correction Transmittals, references to calculational files and the interface discipline verifications.
Selected
- supports, Table X-3, were examined during a plant visit by members of the NRC staff and their consultants.
X.3.4 Staff Findings on the Diablo Problem Program The staff has reviewed and audited considerable documentation associated with the DP Program in general, and has reviewed in detail the response of the licensee with respect to the DP Program concerns stated in Item 6 of License Condition 2.C( ll).
As a result of those reviews and audit, the following findings have been made:
(1)
Initially in 1974 and up to August 1982, inadequate procedures existed to control the DP process.
(2)
Throughout the period, design information has been transmitted (beyond the intent of DP Program) by the DP process.
(3)
Current procedures do not prevent design information from being transmitted by the DP process.
(4)
Current DP procedures are adequate to insure that design information contained in the DP will be incorporated in the as-built process and in the related design calculations.
(5)
The procedure for licensee review 'of its DP Program in response to License Condition 2.C(11) was adequate and appropriately implemented.
(6)
No cases of DP's with significant design information were found that were not already considered significant by the licensee in their review.
(7)
For the cases observed at the plant-site.
the inspection confirmed the as-built drawings contained in the OP file were also contained in the design calculation file and in the final as-built, approved engineering file associated with the pipe support.
(8)
Where design information/modifications were allowed by the OP process, all cases with one exception were identi-fied and were properly documented.
One DP (the exception in Finding No. 8) allowing an eight, inch relocation of a hanger resulted in an omission of the hanger relocation in the piping stress analysis.
The staff does not consider this to be a fault of the OP procedures or process but rather an isolated error in correcting a drawing.
The 127 missing DP's represent 4X of the total number of DP's issued.
Based on the results of this review, the staff believes that the licensee's as-built process provides adequate assurance that action required to resolve those OP's was taken and incorporated into appropriate drawings and calculation packages.
The staff finds the licensee's program developed in response to License Condition 6 to be adequate.
Although the DP program allowed design information to be transmitted, the information is included by procedure in the gA controlled as-built drawings and accepted by design calculations.
~
5
~
I
\\
I n
25 The inspection at the plant site provided the reviewers confidence that adequate construction practices had been employed and that the safety related supports, based on the reviewer's engineering
- judgment, possessed more than adequate strength to perform their intended function.
I The NRC staff concludes that License Condition 6 has been resolved by the licensee.
26 X.5 REFERENCES X-1.
X-2.
J. 0. Schuyler letter to D.
G. Eisenhut, Docket No. 50-275, OL-DPR-76, Diablo Canyon Unit 1, Response to Board Notification 84-017, PGSE Letter OCL-84-131, April 4, 1984.
J. 0. Schuyler letter to D.
G. Eisenhut, Docket No. 50-275, OL-OPR-76, Diablo Canyon Unit 1, License Condition 2.C. 11 - Final Report.
PGSE Letter DCL-84-203, June 1, 1984.
X-3.
J. 0. Schuyler letter to O.
G. Eisenhut, Docket No. 50-275, OL-DPR-76, Diablo Canyon Unit 1, License Condition 2.C.(11),
PGSE Letter DCL-84-164, April 27, 1984.
X-4.
X-5.
J.
- 0. Schuyler letter to D.
G. Eisenhut, Docket No. 50-275, OL-DPR-76.
Diablo Canyon Unit 1, License Condition 2.C.( 11) - Supplemental
- Response, PGSE Letter OCL-84-190, May 18, 1984.
I. T. Yin, Diablo Canyon 1 Draft Investigation/Inspection
- Report, Rev. 3, March 29, 1984 (Preliminary).
SSER FOR LICENSE CONDITION 2.C ll, Item 7 "PGSE shall conduct a progiam to demonstrate that the following technical topics have been adequately addressed in the design of small and large bore piping supports:
(a)
Inclusion ot warping normal and shear stresses due to torsion in those open sections where warping effects are significant.
(b)
Resolution of differences between the AISC Code and Bechtel criteria with regard to allowable lengths of unbraced angle sections in bending.
(c)
Consideration of lateral/torsional buckling under axial loading of angle members.
(d)
Inclusibn.of axial and torsional loads due to load eccentricity where appropriate.
(e)
Correct calculation of pipe support fundamental frequency by Rayleigh's method.
(f)
Consideration of flare bevel weld effective throat thickness as used on structural steel tubing with an outside radius of less than 2T.
PGSE shall submit a report to the NRC Staff documenting the results of the program."
A.
PGSE has addressed the technical topics (a), (c), (d), (e) of the License Condition through the following steps:
1.
The S/B 8 L/B pipe support design criteria memorandum H-9 has been revised to include general instructions to address these topics.
The staff has reviewed these revisions and has found them acceptable.
2.
OCP Instruction No. I-b9, Rev.
0 has been issued, which addresses these topics in considerable and specific detail for application to S/8 pipe supports.
The staff has reviewed this Instruction and the application of this Instruction to the current review by the OCP of S/8 piping supports under License Condition ¹1 requirements and finds it acceptable.
3.
A similar instruction sheet has been issued to provide verification that these topics have been addressed in the design of L/8 piping supports.
The staff has reviewed this instruction sheet and finds it acceptable.
4.
PGSE has addressed the concern in technical topic (b) by submitting additional information regarding allowable unbraced lengths of angle beams.
This information consisted of technical papers which have appeared in foreign (Australian) engineering literature, and a technical paper which appeared in the Engineering Journal ot the American Institute of Steel Construction (A1SC)
First quarter 1984.
The staff has reviewed this information and has concluded that the unbraced length criterion for angle members which PG8E adopted and used in the design of OCNPP piping supports is acceptable.
- However, PGEE has also.committed to reduce the unbraced length of angle member of new supports to correspond to that specified for wide flange beams as specified in the AlSC Construction Code.
The staff finds this acceptable.
5.
PGIIE has provided information in its submittal of Hay 18, 1984 pertaining technical topic (f).
They stated that they have verified that the tubing steel which was used at DCl has been manufactured with minimum corner radii of 2T.
Provided this minimum radius is present, the American Melding Society 01.1 requirement regarding the size of the weld effective throat in flare bevel welds to steel tubing as specified by PGEE on their drawings is acceptable.
B.
PGLE has also addressed satisfactorily the following technical topics related to those of L'icense Condition 7 and 1:.
1.
Specification of the correct angle of inclination (beta-angle) for angle section members when using the.STRUDL program.
A detailed instruction, NO. 1-58, Rev.
0 has been issued addressing this concern.
The staff has reviewed this instruction and finds it acceptable.
2.
PG8E has issued Calculation NNP-1319 "Calculation for ll Types of Baseplate and Anchor Bolt Design Assemblie's" consisting of a set of tables used by designers for quick verification of flexible baseplate adequacy.
The staff has reviewed the basis and documentation of these tables; no independent verification has been made but they appear reasonable and are therefore acceptable.
- 3. Methodology for calculating piping tributary masses for pipe supports.
PGSE has stated that these
- masses, used for the calculation of pipe support frequencies are determined based on a static analysis of the piping system subjected to a loading of one "g" in each global direction.
The statt has 'discussed this method with PGIFE and find it acceptable.
- 4. Buckling criteria for B31. 1 components.
PG8E has modified buckling criteria in Design Memorandum DCM-Mg to satisfy the staff concerns regarding the conservatism of these criteria by reducing the allowable buckling stress for axially loaded members to that corresponding to the A1SC jurisdictional region.
The staff finds this acceptable.
- 5. Basis for the generic qualification of lugs and lug induced local pipe stresses.
PG&E has provided information regarding the generic design of small bore piping lugs, which is based on the selection of the ten highest combined load and pipe stress at lug locations, nine calculations for the highest computer analyzed thermal pipe stress at lug locations,a nd two specific calculations corresponding 'to the two identified lug locations with effective axial spans larger than 100 ft.
The local stresses induced in the piping were computed using WRC Bulletin 8107, and the qualification ot these stresses was based on ASME Code Case N.318.
The staff has reviewed this information and finds it acceptable.
- 6. 'dditional technical topics which the staff has discussed with PGI%E are:
a.
STRUDL calculation of displacement and load responses of angle section beams.
b.
gualification of U-bolts by load rating.
PGI%E provided information on these topics which the staff found acceptable.
Based on the results of actual loading for a random sample of U-bolt load calculations PGIIE has ~ee4saaky decided to base the qualification of any new U-bolts in DWG 049243 on the load rating recommended by the manufacturer, ITT-Grinnell, beginning with Revision 15 to this guide.
D.
PGSE has completed its review of the sample of 200 large bore piping supports, to demonstrate on a sample basis that the technical topics listed in this license condition have been adequately addressed in the design of the large bore supports.
The tonal results of the review were provided in the letter of June 8, 1984, DCL-84-219, which showed that the designs of the large bore supports considered in this sample addressed this license condition.
The staff has reviewed this information and finds it acceptable.
In the course of this review, PGSE determined that one large bore support was shown not to be qualified for ODE conditions due to the omission of a small bore piping load acting on the support.
This support is also used for supporting small bore piping.
Fourteen other supports in the sample of 200 are also of the same type.
PGSE was therefore required to verify that a sample of 30 of these 0
supports selected at random remain qualified under all loading conditions.
PGSE has stated that for all supports of this random sample all loads were accounted for properly, and these supports therefore remain qualified.
PGKE will submit this verification by July 9, 1984.
IDVP REEVALUATION BY STAFF SPECIAL TASK GROUP I,
INTRODUCTION The Independent Design Verification Program (IDVP) for Diablo Canyon was required by Commission Memorandum and Order CLI 81-30.
The IDVP scope and limitations were specifically approved by the Commission prior to its implementation.
Implementation of the IDVP was performed by a number of independent organizations under the overall management of Teledyne Engineering P
Services (TES).
Piping and pipe support design and analysis verifica-tion was performed by R. L. Cloud Associates for Teledyne.
The staff in Diablo Canyon SER Supplements 18, 19 and 20 described the IDVP and indicated that it had acceptably accomplished its identified goal of design verification of large and small bore piping and associ-ated supports.
In Supplements 21 and 22, the staff discussed its evaluation of a number of allegations which had been received, some of which addressed piping and supports.
The staff continues to receive and review allegations involving piping and supports.
Several questions were raised in early 1984 concerning the IDVP follow-ing inspections performed in response to allegations concerning design
control as related to large and small bore piping and pipe supports.
Principally, the concerns deal with sample size justification for the acceptability of span-rule analyzed small bore piping, whether the identification of a large number of comments, perceived to be defi-ciencies in IDVP ITR's conflicted with a decision not to expand the IDVP
- scope, and the appropriateness of the sample size distribution taken from the various groups analyzing large bore piping and supports.
In order to evaluate these
- concerns, a special task group visited the office of R. L. Cloud Associates during the week of June 18 to audit; question and better understand the judgement which went into formulating IDYP decisions in the above matters.
The special task group evaluated the overall IDUP process, including the methodology for its. reviews.
This included the IDVP evaluation of design procedures and criteria, its sampling reviews which included actual pipe and support analysis pack-ages, correlation of analyzed with the as-built item, and its own independent analyses of selected piping systems and supports.
The special task group reviewed approximately 15 of the IDVP review packages for large and small bore piping and associated supports.
These package reviews involved substantial quantities of back-up material which'as retrieved from remote storage to permit task group members to understand decisions reached by IDVP including IDVP analyses.
Recognizing that the IDVP Interim Technical Reports
( ITR's) were summary documents, the task group compared the contents of these reports with the total information available on a given topic.
The task group believes that it is difficult to clearly understand the basis for some of the IDVP decisions reached on the acceptability of pipe and pipe supports designs and analysis based solely on what is available in the ITR's.
However, with the benefit of the information in the back-up IDVP review packages, the task group believes that comments made in the ITR's which may appear to be significant on the surface, can be placed into proper perspective.
II.
PRINCIPAL INSPECTION CONCERNS A.
Acce tabilit of S an Rule Anal zed Small Bore Pi in A series of inspections performed in response to allegations included review of the Independent Design Verification Program
( IDVP) performed by R. L. Cloud Associates (RLCA).
A concern resulting from these inspections is the licensee's basis for quali-fying, without further evaluation, the approximately 15,000 ft. of piping analyzed by span rule and its associated pipe supports.
The inspector noted that the licensee's justification for qualifying this piping is based on the review of a 5,000 ft. sample of pipe
'nalyzed using the ME-101 computer code.
B.
Evaluation of S an Rule Anal zed Small Bore Pi in
The NRC staff has discussed this issue with the licensee and. R. L.
Cloud Associates.
The staff believes that there was sufficient justification for RLCA in the IDVP to accept the span rule piping as meeting licensing criteria.
The staff did request additional information from the licensee to confirm its understanding of span rule analyzed piping characteristics.
This was provided in PGEDCL letter 84-254 of July 3, 1984.
The NRC staff's evaluation of the licensee's basis for accepting, without further evaluation, the span rule qualified piping and,the IDVP's rationale for concurring with the licensee's conclusion is addressed in subsequent paragraphs.
A significant portion of the small bore piping in the Diablo Canyon plant was initially qualified using span rules (File 44).
Small bore at this time included all piping with a nominal diameter equal to or less than six inches.
During the evolution of the seismic design criteria and with the initiation of the Corrective Action
- Program, the definition of small bore piping was revised to include piping whose nominal diameter is less than or equal to 2 inches.
All piping greater than 2 inches nominal diameter has been computer analyzed as has much of,the currently defined small bore piping.
~ I
>)f P
~
j 1
s o
~
gq,41'
',',V Ah'(t~Pt'g',g 'g&l 1Ltl'4'L
<lg I The small bore piping now qualified solely by span rule in the Diablo Canyon plant consists of piping with the following charac-teristics:
o Nominal pipe diameter is 2 inches and less; o
All relatively cold piping (design temperature is less than 160'F for stainless steel or 200'F for carbon steel);
o No large concentrated masses such as motor operated valves; o
Small seismic anchor movements; o
Small thermal anchor movements; o
Existence of over spans causing overstress considered very unlikely.
The licensee reviewed the File 44 span criteria and verified its acceptability for the Hosgri event.
The IDVP also reviewed this span criteria.
All small bore piping which does not have the above noted characteristics has been computer analyzed as have the associated supports.
The IDVP reviewed the licensee's Corrective Action Program, including the basis for not specifically
-6>>
requalifying portions of small bore piping and pipe supports and agreed that this was acceptable.
B, Distribution of IDVP Audits Amon Various Grou s Performin
~Anal ses Large bore piping and support analyses under the Corrective Action Program for Diablo Canyon Unit 1 were performed by the Diablo Canyon Project (DCP), Cygna, Impell (formerly EDS) and Westinghouse.
The IDVP special task group was interested in determining the reasons and basis for the distribution of the analyses reviewed by the IDVP since the'number of analyses reviewed were not proportion-ately distributed among the various design organizations according to the number of analyses performed by these organizations.
C.
Evaluation of A ro riateness of Sam le Distribution Amon Various Grou s Anal zin Lar e Bore Pi in and Su orts For the review of DCP corrective action analyses of large bore piping and supports, the IDVP chose analyses that would reflect various combinations of the following considerations:
Configuration of piping o
Connected to flexible equipment
o With branch lines and/or overlaps o
With heavy in-line components (i.e., remote-operated valves) 2.
Building location and application of spectra o
Piping attached to the containment annulus and/or turbine building o
Piping spans between buildings
, o Piping attached to pipeway and/or auxiliary building flexible slabs 3.
Characteristics of piping o
High energy lines (design temperature 200 degrees Fahrenheit and design pressure 275 psig) 4.
Groups performing analysis o'CP o
CYGNA (EES) o Impell (EOS Nuclear) 5.
Oesign analysis results o
High stress ratio o
High number of support modifications required
~
I All five of the considerations were given attention and the review sample selection was such that the distribution among the various contractors was not proportionate.
There are various detailed reasons that the distribution was not proportionate by contractor.
At the time the sample selection was being made the results of the IDVP gA review were being made available.
The results showed that historically the Cygna and Impell organizations had a strong gA program.
Therefore, under 4 above, the IDVP did not believe it was necessary to choose large sample sizes for these contractors.
Work by contractors under the Corrective Action Program was under I
the same procedural controls as work within the Diablo Canyon Project (DCP).
Therefore, the IDVP did not regard that there was any significant differences between the interfaces within the DCP and interfaces between OCP and contractors.
Under the Corrective Action Program, about half of the piping analysis work performed by Impell was fire protection system piping and supports.
The IDVP felt that since these are low temperature and low pressure lines and since there were other safety significant considerations in selecting review samples, it was not necessary 'to review more than one of these lines.
One of the considerations in the sample selection was the impor-tance of reviewing piping attached to flexible equipment.
The Cygna scope of Corrective Action Program work included one piece of flexible equipment.
This was included in the IDVP review.
The Impell scope did not include any flexible equipment.
All of the flexible equipment in the OCP scope was included in the IOVP review.
Because of the high importance attached to this consid-eration, higher sampling of OCP scope occurred.
The Westinghouse scope of work was not included in the IDVP.
This matter was the subject of a prior staff evaluation at the time the IDVP program plan was reviewed.
Therefore, the staff did not discuss this subject during the team visit to the RLCA offices.
Based on the points discussed above regarding the basis for the distribution of analyses reviewed by the IDVP, the staff concludes that an appropriate sample distribution was selected by the IDVP.
O.
Lar e number of ITR-identified "deficiencies" and the conse uent need to ex and the IDVP Sco e
During the verification review of L/8 and S/B piping and supports, the IDVP (RLCA) identified a variety of deficiencies and concerns.
The results of this review were summarized in a series of Interim Technical Reports
( ITR's) as follows:
ITR 59 - L/B Piping ITR 60 - L/B and S/B Piping Supports ITR 30 8
61 - S/B Piping In the course of investigating certain allegations regarding the design qualification of S/B piping and supports at
- OCNPP, a concern regarding the IDVP review of the DCP effort in-the piping area was identified with respect to the number of comments in the ITR's perceived to be deficiencies by the inspector.
The L/B piping and support analyses were questioned as to ac-ceptability without expanding the review sample size due to the j
large number of identified deficiencies.
The IDVP identified deficiencies of varying kinds in all, except one, L/B piping analyses which was reviewed.
A similar concern for S/B supports by the inspector was raised.
The requirement that the OCP review all computer analyses S/B pipe supports as stated in License Condition 2.C. (11), Item 1 of the OCNPP 1 Operating License later made this
'oncern moot.
E.
Evaluation of "deficienc " si nificance based on s ecial task rou review of IDVP review acka es The special IDVP task group reviewed the documentation of the design review performed by RLCA of some of the OCP design packages of piping and supports; some of the packages reviewed are the following:
A.
L/B piping, ITR 59:
1.
Phase I and Phase II review 2.
OCP 88-117, Rev.
2 3.
DCP 812-101, Rev.
0 B.
S/8 Piping, ITR 61:
1.
OCP 819-307H, Rev.
3 C.
L/8 8 S/B Supports, ITR 60:
1.
DCP PS-1281, Rev. 3:
Support 10/70 SL 2.
DCP OS-582, Rev. 7:
Support 56N/92R 3.
OCP PS-497, Rev.
10:
Support 57N/34R Each RLCA design review package was reviewed thoroughly by one or more members of the special IDVP task group together with RLCA personnel.
For each package the appropriate RLCA checklist and documentation was reviewed in detail to determine the actual nature of each listed deficiency or discrepancy and in particular to determine the significance of those deficiencies listed in the ITR's.
(The number of deficiencies listed in the review packages was greater than that which appears in the ITR's).
In all cases the staff and RLCA members reviewed the nature of a given deficiency and its ultimate resolution.
Based on this review the staff concluded that the effort performed by RLCA was much more extensive than that which was described in the ITR's.
Furthermore, the significance of the deficiencies listed in the ITR's was not addressed in sufficient detail i the ITR, so that it is possible that the ITR description of these deficiencies could be misunder-stood.
As a result, the task group believes that a valid ITR criticism is insufficient description and documentation even though this criticism has no bearing on IDVP acceptability.,
It is recognized that the ITR's were meant to summarize the RLCA review effort, but in retrospect they should have contained considerable more detail than was presented.
During the time of the previous (original) review of the ITR's, the staff acceptance was based on, understanding of the total IDVP effort based on direct communication between the staff and RLCA, rather than just a strict reading of the ITR contents.
III. FINDINGS REACHED BY THE SPECIAL IDVP TASK GROUP Based on its review at RLCA, the special IDVP task group has the following findings regarding the IDVP effort on design of L/B and S/8 piping and supports:
1.
That the IDVP did examine the licensee's basis for not specif-ically requalifying the small bore piping not addressed by the licensee's Corrective Action Program and concluded that licensing criteria for this piping was satisfied.
That the IDVP effort, together with the additional confirmatory characteristics verification performed by the task group, provides an acceptable basis for accepting this pipe.
2.
That the IDVP selected a sample size distribution among the various groups performing large bore piping and support analyses based on a number of well founded judgmental factors and that there was no need to base such samples purely on amount of work performed by each group.
3.
That the number and type of samples chosen by RLCA was adequate for the purposes of the IDVP, namely, verification of DCP design methodology, conformance with licensing criteria, and detection of significant, generic type deficiencies in the DCP verification effort.
In addition, the task group agreed with RLCA that it is highly improbable that any additional significant issues of a generic nature would have been discovered if the sample size had been expanded.
4.
That based solely on a review of the IDVP work reported in the
ITR's, the inspectors concerns of perceived unexplained ITR "deficiencies" were justified.
The ITR's can be criticized as lacking in complete description and documentation.
- However, based on its review of the backup IDVP review packages, the task group has concluded that the identified "deficiencies" were not significant and did not disturb the final IOVP conclusion that the Diablo Canyon licensing criteria was met.
The task group also verified and concurred with the resolution of the deficiencies and discrepancies as described in the ITR's and the corresponding IOVP review packages.
Those that were not classified as generic were resolved based on alternate cglculations or on engineering judgement; for these latter ones the staff reviewed and concurred with the RLCA conclusions.
Generic deficiencies were followed up by the IDVP to ensure that the OCP has properly corrected them.
5.
That the IDVP detected the random input errors of the kind which prompted reanalysis of the small bore piping supports under License Condition 2.C.(ll) item fl.
THese input errors were largely of the calculational and modelling types and were judged by the IDVP not to have an impact on satisfying the licensing criteria.
The omission by RLCA of mention of the issues addressed in license condition item 7 is considered a
deficiency of the IDVP.
In retrospect, the omission appears not to have been significant based on the results of the review by the OCP of all small bore computer analyzed supports and the sample of 200 large bore supports, that there was no impact on satisfying the licensing criteria.
Oecause of the above findings reached by the special task group reevaluating the IDVP, the staff concludes that its earlier eval-uation, i.e., that the IDVP goal of design verification of large and small bore piping and associated supports had been achieved, remains valid.
C.
Programmatic Issues As a result of inspections conducted onsite to verify the effectiveness of design control measures utilized by the Onsite Project Engineering Group (OPEG),
a number of deficiencies were noted.
These deficiencies can be summarized as follows:
a.
inadequate personnel indoctrination and training to assure effective implementation of all gA and technical program requirements; b.
inadequate site procedures and use of unauthorized documents to perform work functions; c.
inadequate procedural control of preliminary design data and design interfaces between onsite groups and offsite groups; d.
lack of timeliness of project responses to site personnel safety concerns and gA audit findings; e.
inadequate gA program audits that well ensure that all aspects of design control requirements are implemented in accordance with program provisions and ensure that the audit results are thoroughly evaluated prior to accepting any corrective actions; f.
inadequate tolerance clarification program implementation to assure that adequate design reviews are made prior to major hardware modifications.
On June 14, 1984, the licensee recinded the authority of OPEG to perform final safety-related engineering work.
All remaining activities are to be performed by the project engineering organization in San Francisco.
Support activities, such as field walkdowns, construction feasibility
- checks, and interfacing will still be performed by OPEG.
This decision by the licensee to redefine the authority and activities of OPEG was, discussed with the licensee during the audit on June 21 and at the public meeting on July 2.
This action does not rectify any design deficiencies that may have resulted prior to June 14, 1984; however, the Group's detailed audit of these design activities, as well as the find-ings of IOYP, results in confidence that licensing criteria have been met.
In addition, the Group questioned the licensee on his actions to assure that this transfer of responsibility will be effectively controlled.
The Group plans on an audit of the eFfectiveness of this license action in the near future.
Therefore, it is our conclusion that the actions taken by the licensee, coupled with the Group findings on the adequacy of technical work performed by OPEG, resolves this issue.
f'.
~
~ 0 I,