IA-84-741, Forwards Inputs to Sser 24,including Staff Evaluation of 840202 Petition Filed by Govt Accountability Project Inst for Policy Studies & Updated Info on Allegations 39 & 45. SALP Input Encl
| ML20244D033 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/10/1984 |
| From: | Houston R Office of Nuclear Reactor Regulation |
| To: | Novak T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17325B782 | List:
|
| References | |
| FOIA-84-741, FOIA-84-742 NUDOCS 8408290207 | |
| Download: ML20244D033 (25) | |
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J,} UNITED STATES 2 g NUCLEAR REGULATORY COMMISSION j.
O WASHINGTON. D. C. 20555
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JUL 10 1984 MEMORANDUM FOR: Thomas M. Novak, Assistant Director for Licensing, Division of Licensing FROM: R. Wayne Houston, Assistant Director for Reactor Safety, Division of Systems Integration
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT, UNITS 1 AND 2 -
SER SUPPLEMENT NO. 24
References:
(1) Petition filed by Government Accountability Project Institute For Policy Studies on February 2, 1984 (2) Letter from D. A. Brand to H. R. Denton, dated March 29, 1984
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(3) Letter from B. W. Sheron to G. W. Knighton, dated April 19, 1984 (4) Letter from G. W. Knighton to J. O. Schuyler, dated May 21, 1984 (5) Tetter form J. 0. Schuyler to G. W. Knighton, dated
_May 24, 1984 -
(6) Letter from J.~0. Schuyler to G. W. Knighton, dated June 6, 1984 (7) Letter from J. O. Schuyler to G. W. Knighton, dated
_ _ , July 2, 1984 Plant Name: Diablo Canyon, Units 1 and 2 Docket Number: 50-275/323 Licensing Stage: OL Responsible Branch: Licensing Branch #3 Project Manager: H. Schierling DSI Review Branch: Reactor Systems Branch Review Status: Awaiting Information Enclosure 1 to this memo provides Reactor Systems Branch inputs to Diablo Canyon Units 1 and 2 SSER No. 24. These inputs include the staff evaluation of the petition filed by Government Accountability Project Institute for Policy Studies (GAP) on February 2, 1984 (Items;No..G r153,-154 riS5 -159',*162,U 67, ang 169) and the updated information on"the'a11ecjatfon"No Q SZ,aild;46. Oyrevaluations reflect information in the reference letters. "
Contact:
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A L4 1984 Thomas M. fiovak. 1 1
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Please note that the part of GAP 169 with regard to the administrative actions of PG&E is outside the RSB review scope and is not included in Enclosure.l.
Enclosure 2 contains the staff SALP evaluation. .
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1 R. Wayne Houston, Assistant Director for Reactor Safety Division of Systems Integration
Enclosure:
As stated cc: D. Muller RSB S/Ls R. Capra H. Schierling F. Rosa A. Marchese e
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ENCLOSURE 1 DIABLO-CANYON UNITS 1 AND 2 SSER No. 24 (RSB)
Task: Allegation 39
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(previously addressed in SSER 21 and 22)
ATS No.: RV 83A47 BN No.: 83-169 (10/20/83)
Characterization
,. There is no control room annuciation provided to alert the operator when the
- RHR letdown lire has been isolated during Modes 4, 5, and 6 (hot shutdown, cold shutdown, and refueling, respectively).
Related' Allegations: 37, 40, 45, 177 Implied Significance to Plant Design, Construction, or Operation Previously addressed ,in,SSERs 21 and 22. .
Assessment of Safety Significance -
In SSERs 21 and 22 the staff stated that indication provided in the control
' room of RHR letdown line isolation includes position indication for two valves in series as well as RHR system flow, pressure.< and pump status information.
Although these features provide a capability to assess RHR status, the staff has recognized the need for installation of an RHR low flow alarm. Accordingly, the licensee was required to install an RHR low flow alarm during the first refueling.
Staff Position In SSER 22 the staff stated that the licensee has committed to install the RHR low flow alarm prior to entering Mode 1, i.e., operation above 5 percent power.
-In a letter of June 6,1984, the licensee confirmed that the components which provide the low flow alarm were installed and tested. The RHR system low flow alarm is now functional. The staff concludes that the issue is resolved. The staff evaluation of the design of the RHR low flow alarm is addressed in Allegation 45 of this SSER.
Action Reauired No further action is required relative to the concerns expressed. Region V will inspect the licensee's installation of the low flow alarm through the routine inspection program.
Task: Allecation 45 (previously addressec in SSERs 21 and 22)
ATS Nc.- RV'83A47 BN Nc.: 85-169 (10/20/83)
Cnaracterization Section 5.5 of the Diablo Canyon FSAR describes the autoclosure interlock for the RHR suction _line isolation valves (8701 end 8702). Section 3.4.9.3.a of the Diablo Canyon Technical' Specifications requires power to be removed from these isolation valve operators during Mode 4 (hot shutdown, RCS cold leo temperat'ure is less than 323 F), Mode 5 (cold shutdown) and Mode 6 (refuelino).
Tnis recuirement defeats the function of autoclosure interlock for the valves.
Related Allegations: 37, 39, 40, 177 Imolied Sionificance to Plant Desion. Construction. or Ooeration Previous,1y addressed in SSERs 21 and 22.
Asses sment of Safety Sionificance Previcusly addressec in 5SERs 21 and 22.
Staff ocsition __
In SSER 21 and 22 the staff stated that without power to the isolation valve operators, the plant design does not conform to BTP RSB 5-1, Position B.I.C, for the requir,ement of autoclosure interlock. By having power available to the isola-tion valve during shutdowns ensures an event V (,tatersystem LOCA) will not occur as a result of the operator f ailing to close both isolation valves during a return to power. With power on the isolation valves, a spurious closure of the isola-tion valves would result in a loss of suction flow to the RHR pu=ps. However, the RER low flow alarm would enable rapid operator detection and =1tigation.
In SSEE 22 the staff stated that it is :ne staff position that power be availatie te tne RHR het leg suction isciatien valves when in a shutdown condi-tion ic p.rovide protection agains; intersystem LOCA. Also, the staff stated that the licensee has ccomitted te instali :ne RHR low flow alarm prior ;c enter n; Moce 1, i.e. , operation acove 5 percent pcwer e
In a letter of June 6. 1954, the licenses confirme: na :ne components which ;rovice the icw flew alarm were ins ailed anc testec. Ine RHR system low flow alarm is new fu :ticnal.
~he 'icensee Orc.icec :ne alar cescri::f r 3-d the casis cf :ne alarr se:ccin; i- its 'e: e rs catec .af 22, 1954 anc e.h 2. 1954. In :ne current syster
, '70 ' :icatin; cent c'le's (~:C 5:1A anc E) en :ne RHR um; discharge ci:ing coen :ne corresocncing re:irculation vahes enen ' low crc:s below the se point c' 500 Gt'* The low fio. alarr circuits are connectec to the flow incicating i
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controllers with_ time ~ delay relays. If opening-the recircuTation valves does not result in a flow increase above 500 GPM within 20 seconds of time deiav, the low flow annunciator will ac-ivate. ~
With regard to potential RHR pumo damage, the worst case is an inacvertent closure of tne RHR hot leg isolation valves (s) when the RCS pressure is lower than the RHR pump shutoff head. Based on the operating experiences, the licensee firmly believes that the RHR pump (s) could run a minimum of 15 minutes without pumping fluid and remain operable. Eith the above assurance, the staff finds that there is reasonable time available for operator action to trip RHR pumo(s) following the annuciation of RHR -low flow alarm anc, tnerefore, the oesign of the RHR iow flow alarm is acceptable.
Action Recuired Region V will. inspect the licensee's installation of the low flow alarm through the routine inspection program.
In a letter from G. Knighton of NRC to PGLE dated May 21, 1954, the staff reouestec that the Technical Specification 3.4.9.3 anc operating procedure E-2:11 mu'st be changed within three montns af ter the low flow alarm is installed to reouire power to be available to the RHR hot leg suction isclation valves.
The staf f will report the resolution of tnis action item in a later SSER.
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. l GAP Issue No. 153.
Concern Due to poor circuit design, the RHR hot leg suction valves 8701 and 8702 have potential for spurious closure which might cause damage to the RHR pumps.
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSERs 21 and 22 (Allegation Nos. 37, 45,_and 177), and (2). Item 7 of the Affidavit of Chu yu Liang Regarding Residual Heat Removal System dated March 15, 1984, and (3) Item 4 of the Affidavit of Faust Rosa Regarding Residual Heat Removal System dated March 15, 1984.
GAP Issue No. 154 Concern The spurious closures of the RHR hot leg suction valves (s) could occur when the power is turned off in the Solid State Protection System (SSPS).
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSER 21 (Allegation No. 37) and (2) Item 4 of the Affidavit of Faust Rosa Regarding Residual Heat Removal System dated March 15, 1984.
GAP Issue No. 155 _
Concern The plant Technical Specification and operating
- procedure permits that the power be removed from the actuators for the RHR hot leg suction valves during
~ ~ plant shutdown. This requirement defeats the function of autoclosure interlock for the valves.
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSER 21 and 22 (Allegations 45 and 177), and (2) Item 6 of the Affidavit of Faust Rosa Regarding Residual Heat Removal System dated March 15, 1984.
GAP. Issue No. 159 Concern It is inconsistent between the PG&E commitment addressed in Staff SSER 7 and the Diablo Canyon operating procedure B-2:11. SSER 7 states that all operator actions needed to perform plant cooldown can be accomplished from 4
inside the control room. However, operating procedure B-2:11 requires an operator to leave the control room to manipulate the breakers for valves 8701 and 8702.
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSER 22 (Allegation No. 177), and (2) Item 5 of the Affidavit of Chu yu Liang Regarding Heat Removal System dated March 15, 1984.
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GAP Issue No. 162 Concern There is no control room annunciation to alert the operator when the RHR pumps are in danger.
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSERs 21 and 22 (Allegation Nos. 39, 45, and 177), (2) Item 7 of the Affidavit of Chu yu Liang Regarding Residual Heat Remova'l System dated March 15, 1984, and (3) Item 6 of the Affidavit of Faust Rosa Regarding Residual Heat Removal System dated March 15, 1984.
GAP Issue No. 167 Conc'ern The allegation asserts that the PG&E and the NRC staff have stated that the
, possibility of spurious valve closures is only six in ten million, too remote to be credible. In fact, the spurious closures of RHR hot leg suction valves have happ'ened several times in the operating experiences.
Staff Evaluation The licensee stated in Section 6.3 of Diablo Canyon FSAR that the probability of valves failing to open to perform ECCS function is 6.1 x 10 6 However, the hot leg suction valves are not a part of ECCS. Therefore, the probability of a spurious closure of the RHR hot leg suction valves has not been addressed either by the licensee or by the staff.
The staff evaluation of the spurious closure of RHR hot leg suction valves has been addressed in the following: (1) SSERs 21 and 22 (Allegations 39, 45, and 177), and (2) Item 7 of the Affidavit of Chu yu Liang Regarding Residual Heat Removal System dated March 15, 1984.
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GAP Issue No.-169 Concern
' The allegation asserts that.the RHR hot leg suction valves are safety-related in light =of-the TMI experiences.
Staff Evaluation The staff evaluation of this concern has been addressed in the following:
(1) SSERs 21 and 22 (Allegation Nos. 40 and J77), and (2) Item 6 of the Affidavit of Chu yu Liang Regarding Residual Heat Removal System dated March 15, 1984.
GAP Issue No. G Concern RHR pumps are a part of ECCS. Therefore, the ECCS is vulnerable to spurious valve closures which could cause one or both RHR pumps to self-destruct due '
to operating without fluid.
Staff Evaluation -'
Diablo Canyon Technical Specification Section 3.5.3 requires as a minimum one operable RHR pump for ECCS function during Mode 4. A spurious closure of the RHR hot leg suction valve (s) during this made could cause possible damage of RHR pump (s) and thus reduce availability of ECCS system. The staff evaluation of the RHR pump proteglion against a potential spurious closure of RHR hot leg suction valves has been addressed in the following: (1) SSERs 21 and 22 (Allegation Nos. 37, 39,.45, and 177), (2) Item 7 of the Affidavit of Chu yu -
Liang Regarding Residual Heat Removal System dated March 15, 1984, and (3) Item 4
. of the Affidavit of Faust Rosa Regarding Residual Heat Removal System dated March 15, 1984.
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ENCLOSURE 2 SALP INPUT The purpose of. this enclosure is to document our evaluation of the licensee's performance' during DSI's Safety Evaluation Review. The following criteria from NRC Appendix 0516 are the only ones relevant to this evaluation.
- 1. Management Involvement in Assuring Quality This action was handled by personnel at the appropriate level of management. The utility involved the necessary in-house technical staff.
Rating: Category 2 -
- 2. Approach to Resolution of Technical Issues The applicant performed the work required. The quality of applicant's submittal, was satisfactory.
Rating: Category 2
- 3. Response to.NRC Initiatives .
The applicant's responses to the NRC's Request for Additional -
Information (RAI) was satisfactory.
Rating: Category 2
- 4. Overall Rating: Category 2
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- Date ROUTING AND TRANSMITTAL SUP 7/10/84 initials Date To: (Name, office symbol. room number, buildmg, Agency / Post)
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- s. J. Knight
- 2. R. Vollmer S, -wa __ . _ .. - -1 4.
- 5. Note and Return Action File For Clearance Per Conversation Approval Prepare Reply As Requested For Correction For Your Information See Me Circulate Signature Investigate Comment _
- Justify __
Coordination asMARKs Ref.: R. Vollmer to R. Fraley memo dated 7/6/84 The'"IDVP Reevaluation" which was attachment 8 to the referenced memo has been revised. The attached 4 s . . . ,
copy is the current version. , -
cc: L. Chandler DO NoT use this form as a RECORD of approvals, concurrences, dispos clearances, and similar actions Room No.-B\dg.
FROM: (Name, org. symbo Agency ost)
R. Bosnak .
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IDVP REEVALUATION BY STAFF SPECIAL' TASK GROUP (7//h/$4)
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 4
. its implementation.
Implementation of the IDVP was performed by a number of independent organizations under the overall management of Teledyne Engineering 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
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. 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 coments, perceiv'ed 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.
9 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 IDVP'ecisions d in the above matters. The special task group evaluated the overall IDVP 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 was 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
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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 IOVP 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. Acceptability of Soan Rule Analyzed
- Small Bore Piping 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 analyzed using the ME-101 computer code.
B. Evaluation of Span Rule Analyzed Small Bore Piping
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The NRC staff has discussed this issue with t$e 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 additio6al information from the licensee to confirm its understanding of span rule analyzed piping characterist'ics. Th's wai; 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 JDVP's rationale for concurring i
with the licensee's conclusion is addressed in subsequent paragraphs. '
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A significant portion of tne small bore piping in the Diablo Canyon plant was initially qualified usir.g span rules (File 44). Small bore at this time included'all piping with a nominal diameter equal to or 1ers than six inches. During the evolution of the seismic design criteria and with the initiation of the Cbtrective Action '
Program, the definition of small bore piping was revised to include piping whose nominal diameter sis 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.
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r The sbahLbore piping now qualified solely by span rule in the s." \ <
Diablo Canyon plant consists of piping with the following charac-teristics:
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- 4 2-9 All relatively cold piping (design temperature d
is less than 160'F for stainless steel or 200 F for
, carbon steel);
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o No large concentrated masses such as motor operated valves; I
- o . Sma'l'"l seismic anchor movements; i ,.
o Small thermal anchor movements; o4 Existence of over spans causing overstress considered n , very unlikely.
The licensee revieaed 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 s
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requalifying portions of small bore piping and pipe supports and agreed that this was acceptable. Based on the characteristics of khepipingqualifiedbyspanruleandthereviewofthespanrule criteria. the task group concluded that the acceptabili.ty of this pidin has been demonstrated. .
o C. Distribution of IDVP t$dits Among Various Grouas Performing i
Analyses. f ' '
. Large bdre piping and ' support analyses under the Corrective Action Program for Diablo Canyon Unit I were performed by the Diablo Canyon Project (DCP), Cygna, Impell (fomerly EDS) and
. Westinghouse.
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The IDVP special task group was interested in determining the o
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 cf analyses performed by these organiza.tions.
D. Evaluation of Appropriateness of Samph ;k*. ._4 Jtion Among Various Groups Analyzing large Bore Piping and Supporti L For the review of DCP corrective action analyses of large bore i m piping and supports, the IDVP chose analyses that would reflect l various combinations of the following considerations:
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- 1. 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 DCP
,, o CYGNA (EES) o Impell (EDS Nuclear)
- 5. Design analysis results o High stress ratio o High number of support modifications required
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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 QA review were being made available. The results showed that historically the Cygna and Impell organizations had a strong QA 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 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 DCP 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.
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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 DCP scope was included in the IDVP review. Because of the high importance attached to this consid-eration, higher sampling of DCP 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 task group concluded that an appropriate sample distribution was selected by l
l the IDVP.
l E. Large number of ITR-identified " deficiencies" and the l consequent need to expand the IDVP Scope l
i During the verification review of L/B and S/B piping and suppcrts, 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:
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ITR 59 - L/B Piping ITR 60 - L/B and S/B Piping Supports ITR 30 & 61 - S/B Piping In the course of investigating certain allegations regarding the design qualification of S/B piping and supports at DCNPP, 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 large number of identified deficiencies. The IDVP identified deficiencies of varying kinds in all except one of the L/B piping analyses. These were all reviewed by the task group. A similar ,
concern for S/B supports by the inspector was raised. The requirement that the DCP review all computer analyses S/B pipe supports as stated in License Condition 2.C. (11), Item 1 of the DCNPP 1 Operating License later made this concern moot.
F. Evaluation of " deficiency" significance based on special task group review of IDVP back up packages The special IDVP task group reviewed the documentation of the design review performed by RLCA of some of the DCP design packages
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of piping and. supports; some of the packages reviewed are the following:
A. L/B piping, ITR 59:
- 1. DCP #4A-100, Rev. 0: Phase I and Phase II review
- 2. DCP #8-117 Rev. 2
- 3. DCP #12-101, Rev. O B. S/B Piping, ITR 61:
- 1. DCP #19-307H, Rev. 3 C. L/B & S/B Supports, ITR 60:
- 2. DCP #S-582, Rev. 7: Support 56N/92R
- 3. DCP #S-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. 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.
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Furthermore, the. significance of the deficiencies listed in the ITR's was not addressed in sufficient detail in the ITR's, so .that it is possible that the.ITR description of these deficiencies could be misunderstood. During the time of the previous (original) review of the ITR's, the staff acceptance was based on understand-ing of the total IDVP effort from direct communication between the staff and RLCA, rather than just a strict reading of the ITR contents. Nevertheless, the task group believes that a valid criticismisinsufficientdescriptionanddocumentationinthe ITR's 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 for those not directly connected with the IDVP, the ITR's should have contained more. detail than was presented. However, based on its review of the backup IDVP packages, the task group has concluded that the identified deficiencies were not significant and did not disturb the final IDVP conclusions that the Diablo Canyon licensing criteria were met.
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/B 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 I
e 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 the adequacy of 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 sample distribution 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.
l 4 That based solely on a review of the IDVP work reported in the ITR's, the inspector's concerns of perceived unexplained ITR
" deficiencies" were justified. The ITR's can be criticized as l
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o lacking in complete description and ' documentation. However, based on.its review of the back up IDVP packages, the task ~
. group has concluded that the identified " deficiencies" were not significant and did not disturb the final IDVP conclusion that the Diablo Canyon licensing criteria was met. The task group also verified and concurred with the resolution of the deficiencies as described in the ITR's and the corresponding-back up IDVP packages. Those that were not classified as generic were resolved based on alternate calculations or on engineering judgement. For the deficiencies resolved by engineering judgement, the task group reviewed and concurred with the RLCA conclusions. Generic deficiencies were followed up by the IDVP to ensure that the DCP had 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.(11) item #1. 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 DCP of all small bore computer analyzed supports
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and the sample of 200 large bore supports, that there was no impact on satisfying the licensing criteria.
Because 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.
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JUN 2 91983 Docket Nos.: 50-275 j and 50-323 MEMORANDUM FOR: Lawerence J. Chandler,. Deputy Assistant Chief Hearing Counsel. OELD FROM: Thomas M. Novak. Assistant Director for Licensing, DL
SUBJECT:
DIABLO CANYON, CCWS SER Enclosed for your concurrence is Supplement 16 of the Diablo Canyon SER. .
The technical review has been completed and coments have been incorporated.
, Please indicate your concurrence by signing below and return this memo to .
l the PWject Manager (A. Vietti. Mail Stop 128) not later than July 6,1933.
Original signe'd ty:
- 3. J. Youngblood
-Thomas M. Novak. Assistant Director r
for Licensing Division of Licensing
Enclosure:
As stated l
Concur, t
DISTRIBUTION f
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o UNITED STATES ~
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. 2, I NUCLEAR REGULATORY COMMISSION wasNINGTON. O. C. 20508 k..../ .
3 1984 i
MEMORANDUM FOR: Richard Vollmer, Director Division of Engineering FROM: Frank J. Congel, Chief Radiological Assessment Branch. OSI
SUBJECT:
DIA8LO CANYON RADIATION EXPOSURE LEVELS EXPECTED AT LOW POWER 1
- RAB has provided estimates of radiation exposure levels in reply to your request for an estimate of expected personnel radiation exposure during Diablo Canyon i
plant walk down to inspect seismic provisions for adequancy. Our estimates * .
were based on the following assumptions:
(1)The inspection will begin at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the first plant shut down from not more than 10% reactor power operation, (2) The inspection will be conducted in compliance with ALARA policy,
- (3) One person will be exposed to radiation. '
1 (4) Fuel assemblies in the core will be essentially leak free, and (5) Inspection will exclude the vicinity of reactor vessel cavity.
f conditions were adjusted to this particular case. Data and experiences g The results show that average radiation levels in the vicinity of most seismically affected pipino at Diablo Canyon should be less than 1 mrem /hr.
- sonnel exposure time of -10 hours. the average personnel exposure shouldThus, assu be approximately 10 mrem.
i Higher personnel exposure could be expected in thec'ase that reactor water cleanup system was in operation during-10% reactor power (one or two days long) operation. Radiation fields in the vicinity of the cleanup system
- components could reach in such case, the R/hr range. Thus, in this case a total personnel exposure of approximately 100-200 mrem could be ex-pected, s
I
' Frank J. Congel, Chief Radiological Assessment Branch i
Division of Systems Integration '
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