ML20210E009

From kanterella
Jump to navigation Jump to search
Insp Rept 50-424/86-128 on 850416-860815.Major Areas Inspected:Readiness Review Program Module 22 Re Independent Design Review
ML20210E009
Person / Time
Site: Vogtle Southern Nuclear icon.png
Issue date: 01/02/1987
From: Imbro E, Parkhill R, Sinkule M
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
Shared Package
ML20210C958 List:
References
50-424-86-128, NUDOCS 8702100211
Download: ML20210E009 (37)


See also: IR 05000424/1986128

Text

r ,

..: . A

.

A

Report No.: 50-424/86-128 .

Licensee: Georgia Power Company

P.O.; Box 4545  %

Atlanta, GA 30302

-Docket No.: 50-424- Construction Permit No.: CPPR-108

Facility: Vogtle, Unit 1 Module: Module No. 22, liidependent

Design Review

Reviews Conducted: -April 15-19, 1985; July 1-2, 1985, July 24-Aug.2, 1985;

August 11-15, 1986; and October 6-9, 1986

On-Site Inspections Conducted: Weeks of April 16, 1985 and August 15, 1986 ,

NRC Offices Participating in Inspections / Reviews: ;

Office of Inspection and Enforcement (IE, Bethesda, MD)

Reviewers: E. Imbro, QA Branch, IE

R..Parkhill, QA Branch, IE

S. Athavale, QA Branch, IE -

T. McLellan, Reactor Construction Branch,-IE ,

T. DelGaizo, Consultant (WESTEC Services)

G. Morris, Consultant (WESTEC Services)

J. Blackman, Consultant (WESTEC Services)

J. Kaucher, Consultant (WESTEC Services)

J. Leivo, Consultant (Leivo Associates)

G. Harstead, Consultant (Harstead Engineering)

E. Willhaus, Consultant (Harstead Engineering)

Prepared by: /[m J / P/'Ae [h

R. Parkhill, Team Leader

_ N/#4 /Pt.

Date Sf'gned

Inspection Specialist, IE j

Approved by: 8[ w # A2 /M'/

E. Imbro, Section Chief .Date Signed

Licensing Section, QA Branch, IE

M. Sinkule, Chief

,

l

87 "

Date " Signed' -

Projects Section 3C

h

Division of Reactor Projects, Region II

21gh h 4 '

G

'\

J

1

. .

l

l

l

V0GTLE ELECTRIC GENERATING PLANT UNIT 1 I

READINESS REVIEW PROGRAM

MODULE N0. 22

INDEPENDENT DESIGN REVIEW

_ CONTENTS

Topic Page

S u mma ry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Purpose and Scope of Review.............................. 4

Methodology.............................................. 5

N RC S ta f f Eval ua ti on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 j

General.................................... 7

Structural................................. 8

Hazards.................................... 9

Mechanical Analysis........................ 11

Control Systems............................ 15

Electrical................................. 22

,

System Design.............................. 26

Generic Concern............................ 30

l

! Statement of Module Acceptability (Conclusions).. .... . . . . 34

Li s t of Pe rsons Contac ted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Acronyms................................................. 36

m

2

, ,

1

L_ J

- _ _ _ - _ _ _ _ _ _ _ _ _ _ _ - . _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ - _ _ _ _ _ _ . _ _ _ __. _

. .

V0GTLE ELECTRIC GENERATING PLANT UNIT 1

READINESS REVIEW PROGRAM

MODULE NO. 22

INDEPENDENT DESIGN REVIEW

SUMMARY

In Module No.22 of Georgia Power Company's Readiness Review Program for

the Vogtle Electric Generating Plant, the Stone & Webster Engineering

Corporation conducted an Independent Design Review of the design of the

auxiliary feedwater system by the Bechtel Engineering Corporation. In

areas where the auxiliary feedwater system did not contain the iiecessary

design attributes to be reviewed, other plant systems / designs were selected

for review by SWEC. The NRC monitored the conduct of this module including

an inspection of the review plan preparation, inspection of review plan  :

implementation, inspection of the resolution of observations, and an

inspection of implementation of corrective and preventive actions. In

this report, the NRC accepts Module 22, requiring no further evaluation j

'

or followup activities in the context of this module. The resolution of

electrical power observation 22F-11 remains an open licensing issue. Based

on its review, inspection, and monitoring of the Modules, the NRC also con-

cludes that a technically adequate design process has been implemented for I

the Vogtle Plant and that substantial additional assurance of design adequacy j

has been provided.

I

$ 9

4

.

.

3

l

.- - . - - - _ _ - - - - - .

_

. .. .-

. .

V0GTLE ELECTRIC GENERATING PLANT UNIT 1

READINESS REVIEW PROGRAM

MODULE NO. 22

INDEPENDENT DESIGN REVIEW

1. Purpose and Scope of Review

The purpose of this evaluation is to determine if the results of the

Independent Design Review, performed by the Stone & Webster Engineering

Corporation (SWEC) and presented in the report of Module No. 22, are an

effective and accurate assessment of (1) the state of the design of the

Vogtle Electric Generating Plant, Unit 1 (VEGP) and (2) the implementa-

tion of the design process for VEGP by the architect-engineer firm,

Bechtel Engineering Corporation (BEC). Further, the evaluation tested

the technical justification of the SWEC conclusions in Module No. 22 with

regard to the adequacy of design and effectiveness of the design process,

the appropriateness and effectiveness of corrective or preventive actions

arising from the SWEC report, and the resolution and disposition of

potential generic concerns raised by SWEC.

tileIndependentDesignReview,wasundertakenbyGeorgia

Module No. 22,(GPC) as a result of NRC concerns that the Readiness Review

Power Company

Program, as structured prior to April 1985, took a fragmented approach to

the matter of design process implementation such that intradiscipline

interface, intraorganization interface, and other common design aspects

(e.g., high-energy-line break protection, seismic /nonseismic interactions,

etc.) might not be adequately evaluated. The integrated evaluation of a

specific sample of the design (i.e. the auxiliary feedwater system aug-

mented by other ple,. design attributes) as performed in Module No. 22

resolved the NRC's concerns and provided a single document for evaluation

of the state of VEGP design, with exception of the civil / structural

discioline. Module 1 (Reinforced Concrete Structures), Module 8

(Structural Steel) and Module 13 (Foundations and Backfill, Coatings,

and Post Tensioning) address the status of the design in the civil / structural

area, except for structural interfaces with the AFW system which were

evaluated in Module 22. The design aspects of Module 4 (Mechanical

Equipment and Piping), Module 6 (Electrical Equipment), and Module 16

(NSSS Interface), were integrated into Module 22.

In view of the above, the NRC's review of Module 22 constitutes an overall

review of the design and design process implementation in the mechanical

systems, mechanical components, electrical, and the instrumentation and

controls disciplines, along with common design areas such as high- and

moderate-energy-line break, seismic II/I, flooding, internally generated

missiles, fire protection, and environmental qualification. While this

report does not address the results of the civil / structural modules

(Modules 1, 8, and 13), which have been reported separately, the conclusions

of Section 4 of this report do consider the results of these modules in

drawing overall conclusions as to the adequacy of the design of '/EGP and

the effectiveness of implementation of the design process for the plant.

4

_ _____________

. .

2. Methodology

The NRC approached the review and evaluation of Module No. 22 in a manner

similar to monitoring of Independent Design Verification Programs (IDVPs)

at other NTOL facilities. Specifically, the NRC's inspection program

involved three phases: (1) inspection of design review checklists, (2)

inspection of implementation of the IDR plan (including an assessment of

the technical depth of the review), (3) inspection of the technical docu-

mentation supporting the IDR conclusions including justification of

observation resolutions between the IDR reviewer (SWEC) and the architect-

engineer (BEC), and inspection of the effectiveness of implemented

- corrective or preventive actions (subsequent to closecut of the items by

GPC).

As can be seen in Figure 1, the NRC inspections were performed as follows:

Inspection Location Dates

1. Review Plans SWEC, Boston 7/1-7/2/85

2. Implementation BEC, Los Angeles 7/29-8/2/85

,

3. Resolution of VEGP Site 8/11-8/15/86

i Observations and BEC, Los Angeles 10/6-10/9/86

'

Corrective Action

Figure 1 contains information on the civil / structural modules for purposes

of showing the complete scope of the design review activities of the

, Readiness Review Program and since some NRC inspections involved Module 22

review along with review of one or more of the civil / structural modules.

This report addresses only Module 22 (and those portions of Modules 4, 6,

and 16 which were incorporated in Module 22), and therefore the civil /

structural information is provided for information only to give a total

overview of the Vogtle design process.

In addition, the scope and depth of the design reviews being performed

in conjunction with Modules 4 and 16 were evaluated at the VEGP Site from

April 15 through April 19, 1985. Since these observations were eventually

merged with the Module 22 findings, the resolution of observations and

effectiveness of corrective action associated with these items were

reviewed by the NRC during the appropriate Module 22 inspections cited

above.

l

In each of the above inspections NRC inspectors, with contractor support,

reviewed the design disciplines of mechanical systems, mechanical components,

electrical power, and instrumentation and control. In addition, at each

inspection, the action taken to resolve NRC concerns from previous inspec-

tions was reviewed and evaluated. A report was prepared for each inspection

.

l and prior NRC inspection concerns were closed out in subsequent reports,

provided appropriate action to close the concern had been observed.

Otherwise, these items were carried as open into the next NRC inspection.

The NRC inspection reports associated with the Module 22 review are as

follows:

l

5

.__ . . . . . .

.

V0GTLE READINESS

REVIEW PROGRAM

DESIGN VERIFICATION

CIVIL / STRUCTURAL MECH. EQUIPMENT / SYSTEM-BASED

REVIEW PIPING REVIEW TECHNICAL ASSESSMENT

if If if

- , . MODULES 1,8 , MODULES 4,6 SWEC IDR

AND 13 AND 16 (CH.7) MODULE 22

(AUX. FEED REVIEW)

"

-$$10Y5!'I$s ""vos'7tY's'[r'e"

APRIL, 1ses II

yj,gseecism. REVIEW PLAN

Jutv. ises PREPARATION

If

0$ l2l[ll'*n

eucusi, ises

1MPLEMENTATION

OF PLAN

=

If if

BPC/5WEC ACTION- d$rllS$ii['"

Aususr, ises

Air lE sISb'" +

aususi, 198s

BPC/SWEC ACTION-

ITEM RESOLUTIONS

ITEM RESOLUTIONS

I

I

If

BEC CORRECTIVE e

ACTION

If $$ IS![!s'"

"' '

READINESS REVIEW *

VERIFICATION OF

FIGURE ] CORRECTIVE ACTION

-

. .

Inspection Date Report No.

7/01/85-7/02/85 50-424/85-34R

7/29/85-8/02/85 50-424/85-34R

8/11/86-8/15/86 50-424/86-105R

10/6/86-10/9/86 50-424/86-128R

3. NRC Staff Evaluations

An evaluation of each Section of the SWEC IDR report (Module 22) is

provided in this section, using section numbers corresponding to the

IDR report. Included are a brief description of the section, what was

reviewed, the basis for acceptance, and a statement of any required

follow-up action or follow-up evaluation.

a. Section 1 - Introduction

(1) IDR Report

This section is a general introductory section including background

information on the program and general information as to the content

of the report.

(2) Inspection Results

This section was reviewed for background information only. No followup

action or evaluation of this section is required.

b. Section 2 - Scope

(1) IDR Report

This section provides the basis for selection of the Auxiliary

Feedwater System and other plant design aspects as being a repre-

sentative sample for an independent design review and further

describes the scope of the review.

I

(2) NRC Inspection Results

The NRC staff agrees with the rationale for selection of the

Auxiliary Feedwater System and other plant design aspects as being

a representative sample of the design. Further, the staff concurred

with the scope of the review at the time of inspection of the initial

i

design review plan and checklists during the inspection at SWEC

=

Headquarters (Boston) in July 1985. Accordingly, the staff finds

this section of the report acceptable and no followup action or

evaluttion is required.

,

6

.-.

. .

c. Section 3 - Results and General Conclusions

This section of the IDR report contains the SWEC conclusions for

each of the major sections of the report as follows:

Section Subject

3.1 General

3.2 Structural

3.3 Hazards

3.4 Mechanical Analysis

3.5 Control Systems

3.6 Electrical Design

3.7 System Design

3.8 HVAC System Design

3.9 HVAC Duct Design and Analysis

3.10 Evaluation of Generic /

Programmatic Concerns

This section is the heart of the report. Each of these sections

is assessed by the NRC staff separately in the following material.

Since these subsections cannot be assessed without reference to

the appropriate subsets of section 4 (Review Description) and

section 5 (Review Observations, Responses, Assessments), the

respective subsets of sections 4 and 5 are considered with the

section 3 material in this report.

c.1 Section 3.1 - General

(1) IDR Report

In this subsection, SWEC draws the following general conclusion:

"In conclusion, certain areas of weakness were identified.

These areas were primarily with respect to the adequacy of

the project documentation and program implementation. In

a few instances this led to isolated design deficiencies

and in some cases hardware changes. Due to the judicious

application of design margin based on past engineering

experience during design development, the extent of these

changes was limited. The current programs and corrective

actions, as indicated in Sections 3.10 and 5 of this report

and in Section 7 of each of the civil / structural module

reports, provide reasonable assurance that the final plant

design will be technically adequate and in compliance with

licensing commitments."

(2) NRC Inspection Results

Overall NRC staff conclusions are presented in Section 4 of

this report, Statement of Module Acceptability. Since overall

staff conclusions are presented in detail in Section 4, they

are not repeated in this section. For the reasons given in

7

e

.

Section 4, the staff finds this subsection of the report to be

acceptable. No followup action or evaluation of ini subsection

is required.

c.2 Section 3.2 - Structural (SBTA)

Section 4.2 - Structural

Section 5.A - Structural Observations

(1) IDR Report

Since other Readiness Review Modules (e.g. Modules 1,8, and 13)

addressed VEGP structural design, Module 22 focused on structural

interfaces with the AFW system, design of raceways and supports,

and structural interfaces with pipe supports, raceway supports,

and equipment supports. The IDR team concluded that this portion

of the design was adequate and met licensing commitments and

regulatory requirements.

(2) NRC Inspection Results

The structural assessment by SWEC consisted of the examination

of two design criteria, two specifications, fourteen calculations

and various other design documents. The NRC's assessment of the

observations resulting from this review are presented below:

Observation 22-A6 indicated that for FCRs relating to conduit

support systems span changes, only the effect of the change on

the support was addressed and not the other components such as

the conduit, fittings and clamps. As a result of this observation,

BEC performed a review of past FCRs associated with increased

conduit spans and determined that although the technical justi-

fication documentation for the changes was not complete, structural

evaluation of the changes indicated that the modified arrangements

were structurally adequate. The twelve FCRs identified by the IDR

were revised to include all required technical justification.

Instructions were issued to clarify the requirements of providing

technical justification for concurring with FCRs. In addition,

training of personnel was conducted as part of the implementation

effort. The NRC has reviewed the corrective actions taken,

performed a review of a sampling of FCR written af ter imple-

mentation of the corrective action program and concludes that

,

l the matter has been satisfactorily resolved. This item is closed.

The remaining observations in the structural area are not

,

individually discussed because they were of lesser technical

significance and were satisfactorily resolved. These observations

were reviewed by the staff and all dealt with cases where

engineering judgment in lieu of documenting the details of var-

ious designs had occurred. The staff reviewed the corroborating

details and concluded that no governing design criteria or any

project licensing commitments had been violated. All of the

observations were resolved by BEC by supplying the missing

corroborating information. The staff therefore finds this section

I of the report acceptable. No followup action or evaluation is

required.

8

l

._ . . _ . . . _ _ _ _ _ __ __

. .

4

. c.3 Section 3.3 - Hazards

Section 4.3 - Hazards

4 Section 5.B - Hazards'

(1) IDR Report

This subsection of the report concludes that the hazards area

was found to be technically acceptable. SWEC stated that

project actions initiated in response to hazards observations

' were assessed as adequately addressing resolution of .the-

concerns. SWEC further stated that project commitments to

revise or generate appropriate procedural. requirements,

evaluation sheets, and calculations.were adequate to ensure

safety system functional integrity during postulated in-plant

hazards.

,

(2) NRC Inspection Results

The hazards assessment by SWEC included an examination of

'

approximately: 23 design criteria and project technical

,

guides; 4 topical reports; 24 calculations; 33 drawings; 13

specifications; 31 intradiscipline interface documents; and 5

vendor interface documents. The NRC's assessment of the

.! observations resulting from this review are presented below:

'

Observation 22-B01. identified an incorrect implementation of

<

high-energy-line break criteria, resulting in hardware modi-

fications to maintain safe shutdown capability. Specifically,

longitudinal breaks had not been postulated at intermediate

high stress points for high energy ASME III Class 2 and 3 piping.

Subsequent postulation of longitudinal breaks and evaluation of

consequences on essential system and component targets resulted

in design changes to assure safe shutdown capability. As a

result of this observation, the Licensee reported the event in

accordance with 10 CFR 50.55e. The NRC staff reviewed the

resolution of the observation and concurs that appropriate

corrective action has been taken and considers the specific

technical issue to be closed. With regard to the generic

- implications of a project procedure which failed to correctly

implement design criteria, this matter is addressed by the IDR

in Section 3.10 and is assessed by the staff in the appropriate

section of this report.

l

Observation 22-B02 indicated that due to the unfinished status

of the design with regard to documentation of protection against

internally generated missiles, the IDR reviewer was unable to

adequately assess project activities in this area. Specifically,

at the time of the IDR, missile postulation calculations were

undergoing a general revision. During the NRC's inspection at

BEC in October 1986, the staff reviewed the Summary Report of

the VEGP Internally Generated Missile Analysis and calculation

X6CXD-25 (Missile Analysis-Rotating Equipment). The staff

'

9

.

w , ,-

, w - ,m ,.

w ,mm-~- - , -wn%-aw w w -mw.r---, --

- , . . . ~.,.r-..y- --- - - , - - . ,-+

. .

concluded that a technically adequate analysis for protecticn

against internally generated missiles is in progress (nearly

complete) and is being sufficiently documented. Confirmation

by the Licensee that the analysis was completed is documented

in P. D. Rice's letter to Region II dated November 20, 1986.

This observation is closed.

Observation 22-B03 indicated that maintenance of safe shutdown

capability was not adequately demonstrated in the documentation

of analysis of internal flooding. Specifically, the observation

identified inadequate flooding effects analysis regarding' the

consideration of flooding sources and effects beyond the volume

under evaluation, the procedures and tools used to identify

potential flood flow paths, and consideration of electrical

consequences beyond the flooded volume. The project subsequently

revised the hazards walkdown instructions to assure proper con-

sideration for other plant areas. During the NRC's inspection

at BEC in October,1986, the staff reviewed the hazards walkdown

documentation as well as two Auxiliary Building flooding calcu-

lations (X6CXC-26 and X6CXC-30). The staff concluded that IDR

concerns are being fully addressed and that internal flooding

effects are being sufficiently analyzed. Confirmation by the

Licensee that the internal flooding portion of the hazards

finalization program is to be completed prior to fuel load is

documented in P. D. Rice's letter to Region II dated November 20,

1986. This observation is closed.

Observation 22-804 identified various instances where project

documentation failed to identify the source of design data or

present technical justification for assumptions. The project

subsequently demonstrated that technical deficiencies did not

result from the examples cited in this observation with excep-

tion of the longitudinal breaks discussed in Observation 22-B01

(above). The staff reviewed a sample of these items and con-

siders this observation closed. The generic issue of hazards

documentation is discussed in Section 3.c.8 of this report.

Observation 22-B05 concerned an unjustified assumption that

non-nuclear safety-related items supplied to standard com-

mercial practice provided adequate design margin to withstand

seismic loadings of an SSE without structural collapse. As an

example of this assumption, the IDR identified room space heaters

which could impact safety-related equipment should they collapse

in a seismic event. The project committed to upgrade the support

of these heaters and comitted to adequately consider seismic

capability of commercial grade equipment as part of the hazards

program. Subsequent to upgrading the supports of all wall-

mounted heaters having potentially unacceptable interactions

with safety grade equipment, BEC performed a calculation which

concluded that the heaters would not have collapsed in a seismic

event. The staff considers this observation closed for the

following reasons: (1) the supports for the heaters in question

have been upgraded, (2) the hazards walkdown is considering

l

10

-

. .

t

. .

potential. failure of category 2 equipment-(verified by the

staff during thez l0/06/86 inspection at BEC), and (3) BEC has

. concluded that the heaters would not have collapsed even prior

to the upgrade.

Observation 4-92 identified that the. evaluation of internally

. generated missiles did not evaluate a fan blade missile escaping

through the expansion joint, such as the event that occurred at

the Palo Verde Nuclear Station. The project consnitted to an

evaluation of this missile. During the inspection at BEC the

week-of October 6,1986, the staff reviewed documentation of

the walkdown of all Joy fans in.the plant and the analysis of

potential missiles, particularly those potentially escaping

through flexible expansion joints. The evaluation concluded

that no safe-shutdown equipment would be impacted by potential

missiles. The staff considers this evaluation sufficient.to

address the concern and considers this observation closed.

The remaining observations in the hazards area are.not indi-

vidually discussed because they were of lesser technical

significance and were satisfactorily resolved.

In view of the technical items discussed above, the NRC staff

concurs with.the IDR conclusion that design of the plant in

the area of hazards protection is technically adequate. With

regard to the_ hardware changes made as result of the possible

longitudinal pipe cracks or potential failure of commercial

. grade equipment in a seismic event, these features are very

-conservative design measures imposed on nuclear plants to

provide protection against highly ~unlikely occurrences. Al-

though these measures must be incorporated, and as a result'

of the IDR they have been _ incorporated at -VEGP, the identified

weaknesses in the design process are not considered to be sub-

stantial. With regard to the shortcomings in project documentation

in tha hazards area, these are discussed in subsection c.8 of

this report. The staff finds this subsection of the report

acceptable. No followup action or evaluation is required.

c.4 Section 3.4 - Mechanical Analysis

Section 4.4 - Mechanical Analysis

Section 5.C - Mechanical Analysis - Pipe Stress

Section 5.0 - Mechanical Analysis - Pipe / Duct Supports

' Section 5.M4 Mechanical Equipment and Piping

1.

i

(1) IDR Report

b This subsection of the report concludes that, with exception of

l

-identified observations, piping analysis, pipe support designs,

'

and duct support designs met technical requirements of project

licensing commitments and applicable codes and standards.

l

11

!

i

. .

.

b

Further, corrective and preventive measures were judged to'be

adequate.

(2) NRC Inspection Results

The pipe stress, pipe support, and duct support assessmen'ts-

by SWEC included the examinatian of-approximately: 25 design

criteria, 57 calculations, 28 specifications, 78 drawings and

69 other miscellaneous documents. The NpC's assessment of the

observations resulting from this review are presented below:

Observation 22-C5 identified the incorrect enveloping of response

spectrum in three piping analysis problems associateo with the

auxiliary feedwater system. In the first case, two separate sets

of enveloped response spectra were used; however, a multiple

response spectra analysis was not performed. In the second case,

the selected-response spectra did not-envelop all potential

responses. While in the third case, the project. performed-a

multiple response spectrum analysis which is inconsistent with

Design Criteria DC-1005 and FSAR commitments. As a result of-

this observation, BEC reviewed all high energy, Class 1 and

other analyses within its scope and corrected five analyses.

In addition, DC 1005 and the FSAR were revised to reflect the.

changes discussed above. .The NRC staff reviewed the resolution

of the observation and concurs that the appropriate corrective

actions have been taken. 'In view of'the limited number of

discrepancies found, it does not appear that any systematic .

breakdown in control has occurred. This observation is closed.

Observation 22-C10 identified a situation where a weldolet

formula contained in a Bonney Forge Handbook was used to account

for the stress intensification present at an extruded outlet tee

intersection. As a result of this observation, the project

developed justification for the use of the formula based upon

similarity to geometrics defined in figure NC-3673.2(b)-1 of

the ASME code of record for Vogtle as well as comparison to

test result performed by Bonney Forge and the Pressure Vessel

Research Council (PVRC). In addition, a broadness review was

performed to determine other cases where stress intensification

factors may have been used without strict compliance to pro.iect

documents. A very limited number of situations were found where

nonstandard stress intensification factors were used. Evaluation

3

of these situations by the project indicated stress levels which

I can easily accommodate much larger stress intensification factors

than were used. The staff reviewed the relevant documentation

and concluded that the matter had been addressed adequately. In

addition, there has not been a breakdown in the design process

nor implication of safety impact. This observation is closed.

I Observation 22-C11 concerned neglecting the weight contribution

of pipe support attachments in the piping model for stress

l

12

l

'

l

.. - . _ . _ .

. .

analysis. The project stated that for Class 1 lines, this

factor is considered in.the analysis, while for Class 2 and

3 lines the consideration is of no practical concern. The

majority of supports used in Class 2 and 3 systems are rigid

frames or other designs which do not contribute additional

weight to the piping system. Further most systems are not

subjected to significant dynamic loadings to which such

factors are important. The project agreed, however, to

require evaluation of such effects if.the added weight

4 exceeded 10% of the piping weight for future analyses and

,

as part of the'as built reconciliation program. The staff

reviewed the justification for the project's position and the

implementation of its commitments and concluded that the

i matter wds satisfactorily resolved. .This observation is closed.

4

. 0bservation 22-C12 indicated that the static anchor movement

loading used in ,the RCL loop break is not consistent with

project criteria (DC-1018) and that static equivalent

analyses were performed to evaluate the effects of a LOCA

which may not be conservative. The project stated that the -

anchor movements used were an approximation and that since

.

the leak before break criterion is now being used on the

!~ > project, appropriate LOCA displacements would be.used when

made available by Westinghouse. In addition it was decided

to confirm the acceptability of the static equivalent method

by performing dynamic LOCA analyses for the affected lines.

The required analyses have been performed and were reviewed

l by the staff. The results indicate that the original piping

design is adequate, therefore the matter is considered

closed..

i- In observation 22-001, a review of all voided pipe whip

'

restraints was conducted by BEC and 11 voided restraints

were identified as supporting structure for 12 pipe supports.

- All of the pipe supports in question have been updated and

< additional personnel training in the use of action tracking

'

logs was conducted by BEC. The staff reviewed the response

assessment and 18 pipe support drawings and associated rupture

, restraint drawings to verify concurrence with deletions

identified by BEC. No discrepancies were identified. The

F

staff concludes that the item is closed and the generic

l concerns are answered.

In observation 22-D02, BEC conducted a full review of all

pipe support design loads for all lines in the BEC scope and

identified 60 pipe supports with significant load deviations

out of 2,142 supports on 208 isometrics reviewed. Of these

60 supports identified with load deviations, only one required

j physical change. BEC has issued an instructional memorandum

and conducted personnel training on its provisions. The staff

,

reviewed the response and assessment of observation 22-002.

, In addition, the staff reviewed documentation for completeness

e

1 13

1

4

9,y., _ . , - 9 , , - - - -, . ,-,.,_,w-,.7-._, ,.,..y_ _._,e+ ,_.,m r_,.,,.., , _ _ . _g,, ., - . ,, . , . . . - . . - ~ . , _ . - . _

._ . .-_ - ~_ . __ _ , _ - - __ . .

.

and detail design of 10 pipe supports from SWEC's sample in.

Appendix E, " Corrective / Preventive Action Commitment" of the

. I DR .- No discrepancies were identified during.the review.of

pipe support documentation. The staff concludes from the

.

review of the response, assessment and documentation that this

observation is closed, and the generic concerns are answered.

,

Observations 22-D04 and-011 refer to undocumented use pipe

1 support design guides in calculations and undocumented use:

of computer programs in calculations, respectively. In the

'

case .of 22-D04, BEC has revised DC-1017- revision 5 to assure

that proper documentation is prepared during the reconciliation

f program. In observation 22-011. BEC reviewed 30 calculations

j for use of the correct computer program name and omissions of

f the program name and no discrepancies were identified. The

i staff reviewed the response end assessment of observation 22-D04

and 011. In addition, the NRC inspection reviewed the calcu-  :

'

l

1ations for 10 pipe supports from SWEC's sample in Appendix E

i- of the IDR and did not identify any discrepancies. The staff

i concludes' from the review of. the response, assessment and the

revising of DC 1017 by Bechtel, that the observations are

closed and the generic concerns are answered.

f Observation 22-D06 identified an incorrect movement used for a

spring hanger design. BEC reviewed all 300 spring hangers in

i

, their scope for errors in thermal movements and identified four

,

cases in which errors were made. The identified errors in -

thermal movement had insignificant effect on spring size -

- selection and hot load settings. BEC revised the computerized

- load and movement sumary sheets in 1984 to include all required-

!

data in one section of the' computer printout to eliminate the

i

potential for error. The staff reviewed the response, assessment

! and the calculation for pipe support VI-1301-012-H026 and did not

j identify any discrepancies. Based on BEC's review of all the

- summary sheets for 300 springs in their scope and the revision

of the computerized summary sheets, the staff concludes that

,

j

the observation is closed and the generic concerns are answered.

.

Observation 22-D12 concerned undocumented calculations for

~

-

!

,

snubber settings. BEC stated that the undocumented snubber

L setting in pipe support calculation V1-1201-053-H005 was an .

! isolated error. To verify this was an isolated error, a

j

review of 71 snubber calculations that were_ done by both

' the originator _ and the checker cited in the original finding

was performed and an additional sample of 60 snubber

l calculations by other designers were reviewed for correct

l

.

snubber settings. BEC identified 1 out of the 131 snubbers

reviewed to have a thermal growth discrepancy and the pre-

l

liminary review of the estimated thermal stresses indicated

the displacement discrepancy would not exceed code allowables.

The staff reviewed Pipe Support Design Manual, Section 4.8.1

and 5 snubbers from the sample of 71 for correct settings and

! 14

1

L

!

. ., - - . - - - - - - _ - - - . -- . - - . - - - -

.

no discrepancies were identified. The staff also reviewed

PSDM Section 4.8.1 and concluded it was acceptable for

calculating snubber settings. Based on this review, the

staff finds the resolution of this item acceptable and this

item is closed.

Observation 22-D19 concerned inconsistencies between the stress

criteria for HVAC duct supports and FSAR commitments. The IDR

noted that the stress allowables in calculation X2003 and

Section 3.4 of Design Manual DC-2167, Revision 4, were not

consistent with the commitment in FSAR Sections 1.9.52 and

1.9.140. In response to this observation, BEC did a review

of all civil / structural design criteria for consistency with

FSAR commitments, emphasizing HVAC duct supports and electrical

raceway supports. In its review, BEC concluded that the incon-

sistency with regard to the stress allowables was isolated and

did not cause any hardware changes. The staff reviewed the

documentation associated with the response and identified a

minor administrative error with regard to FSAR Table 3.2.2-2.

The Licensee subsequently issued a SAR change notice to correct

the error. Based on the staff's review of the documentation and

the issuance of the SAR change notice, the staff concluded that

this observation had been resolved adequately. This item is

closed.

The remaining observations in the mechanical analysis area

are not individually discussed because they were of lesser

technical significance and were satisfactorily resolved.

Based upon the review of all observations in the mechanical

analysis area, the staff concurs with the EA conclusion that

piping analysis and pipe support designs meet technical

requirements of project licensing commitments and applicable

codes and standards. The staff finds this section of the

report acceptable and no followup or additional evaluation

activities are required.

c.5 Section 3.5 - Control System

Section 4.5 - Control System

Section 5.E - Control System

,

l (1) IDR Report

l

'

This subsection of the report concludes that the controls

area was found to be technically acceptable. SWEC stated

that project actions initiated in response to the controls

observation adequately resolve the concerns.

!

!

15

!

i

_._

. . . . _

__ - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ . - _ - _ _ _ _ _ _ _ _ .

. .

.

l

(2) NRC Inspection Results

There were 19 IDR observations in the instrumentation and

controls discipline. Of these, 10 had been designated Level

IV (invalid observation) by the IDR team following subsequent

clarification or review of additional information supplied by

the project. The staff reviewed the proiect responses to these

10 observations, interviewed the IDR team, and agreed that with

the clarifications as documented in the IDR, that these obser-

vations had no safety significance.

The following staff comments apply to the observations which

the IDR had designated either Level I or II, and which in some

cases had potential for hardware changes, FSAR revision, or the

appearance of safety significance. The staff reviewed the

project responses to these observations, interviewed the IDR

team, and examined available supporting documentation.

Observation 22-E03 noted an apparent inconsistency between FSAR

commitments regarding AFW " actuated devices" described in the

FSAR and the devices as shown on P& ids. The IDR reviewer had

interpreted " actuated devices" to exclusively signify automatic

actuation but this term was used in the FSAR in a more general

sense (e.g., an actuated device may have only remote manual

control). In response to this observation, BEC explained the

FSAR interpretation, and for additional assurance reviewed

the P& ids, logic diagrams, loop diagrams and other AFWs

documents to assure consistency of design documentation; no

discrepancies were reported in the actuation logic as a

result of that review. As a further result of that review,

BEC identified additional AFW actuated devices that would be

added to the FSAR list for consistency in reporting. The

staff concludes that this observation resulted from differing

interpretation of terminology; there was no technical discrepancy

in actuation logic; and the proposed FSAR revision would improve

reporting consistency. This observation is closed.

Observation 22-E04 identified an inconsistency between the

logic diagram and the elementary diagram for the turbine

driven AFW pump room intr.ke damper. The logic diagram

correctly showed the damper opening on an AFW start signal,

but the elementary showed the damper closing on the signal.

Investigation by BEC verified that the elementary diagram was

incorrect and that the error was missed in the drawing check.

BEC reported that the basic error was selection of a normally

open auxiliary relay contact rather than normally closed

(since this damper closes when its solenoid is energized).

16

__ _. _ l

-

. .

BEC also explained that the contact states required for this

circuit represent about 10% of the damper applications,

implying this may have contributed to the error. BEC checked

the remaining similar cases (28) and found no errors; they

further explained that BEC had independently discovered the

error, and in any case correct operation would be confirmed

during preoperational testing. The staff concludes that this

appears to be a typical isolated error, moreover that it

would be detected in preoperational testing. This observation

is closed.

Observation 22-E06 identified a concern that a vendor has not

adequately addressed orifice cavitation in his sizing criteria,

and that the project may have approved technically unacceptable

criteria. If cavitation is not properly considered, the orifice

would be damaged and its performance affected. BEC had not

specified cavitation criteria to the vendor. In response to

this observation, the project has implemented a program to

evaluate flow elements and orifices for cavitation, and has

identified orifices requiring resizing or replacement with

multistage orifices. At the time of inspection, calculations

had not been issued. The staff agreed that the corrective

action is appropriate, and at BEC, reviewed calculation X4C1202V22

Rev. 3, " Orifice Cavitation Verification Calculation". Revision

2 had been previously reviewed and accepted by the IDR team.

Revision 3 resolved the findings of the IDR team by performing

additional calculations for orifices experiencing cavitation,

and accounting for additional information acquired during

preop testing. The staff spot checked the safety injection

pump miniflow orifice to determine the potential for cavitation.

Based on design information provided by Westinghouse during the

inspection (Westinghouse letter MED-PVE-4635 of 10/8/86), the

staff concluded that there is adequate assurance that severe

cavitation would not be expected for any operating conditions of

that system. This observation is closed.

Observation 22-E08 identified incorrect specification of

orifice and flow transmitter ranges at 0 - 1000 gpm. A BEC

calculation established the low end of the required measure-

ment range to be 146 gpm. The orifice and transmitter range

,

!

l

specified would preclude meeting channel accuracy requirements

l at 146 gpm. BEC has committed to change the ranges of this

I instrumentation to 0 - 600 gpm, stating that this will meet R.G.

1.97 requirements for 0 - 110% of normal design flow while

.

meeting the accuracy requirements. BEC also states that with

l the new range, the reading could be off scale high when

measuring flow monitoring to a faulted steam generator but

that quantitative flow monitoring to a faulted steam generator

.

'

is not within the R.G. 1.97 basis; they also state that steam

generator levels are available and the off scale reading might

help identify the break. The staff agrees with the interpre-

tation of R.G.1.97, and concludes that the corrective action

l

l

I 17

I

-

. .

for AFW flow monitoring is appropriate. BEC stated that the

error. was due to incorrect specification by a mechanical

engineer of the flow range based on the high flow when , feeding

the break, and failure of the controls engineer to recognize

the accuracy problem. A broadness review by BEC indicated that

two setpoint determinations donc by the same mechanical engineer

were incorrect. BEC has concluded.that the problem is limited

to these two enginears, but has committed to further strengthening

its loop verification program to identify any similar design

deficiencies. This connitment includes a review of all orifice

plates and corresponding accuracy requirements. The staff agreed

with the corrective action program proposed, and performed a

followup review of BEC's loop consistency review program. Con-

sistency reviews for approximately 487 loops had been completed,

.

and corrective actions such as changing meter scales had been

identified. The staff discussed with BEC the method of estab-

lishing loop requirements from mechanical / process discipline

inputs, methods for documenting the bases, and methods for

tracking change packages issued against the loop. Several

examples were sampled and found to be thorough and consistent.

This observation is closed.

Observation 22-E09 stated that BEC had not specified over range

protection for differential pressure transmitters, nor had

vendors provided documentation of over range protection. Over

range protection would be provided to assure integrity of the

instrument. BEC indicated that for the specification in question

(X5AD04), over pressure protection had been provided as a

standard feature even though not specified. BEC demonstrated

to the IDR team that adequate over pressure protection had been

provided for a typical pressure transmitter and differential

pressure transmitter in the AFW, and indicated that these require-

,

ments were assured by review of data sheets during bidding and

design. For instruments such as differential pressure switches /

gauges where such protection may not be standard, BEC specified

j

over range protection equal to the rating of the device body;

, body rating is specified by considering the maximum process

pressure. The staff believes omission of over range protection

requirements from specifications is a significant documentation

,

!

e

deficiency, but agrees with the IDR assessment that adequate

'

over range protection appears to have been provided at Vogtle.

This observation is closed.

Observation 22-E10 identified deficiencies in controlling and

I

documenting the basis and calculation of set points and set

! point tolerances. In response, BEC has issued Desk Instruction

l

X5B006 detailing the scope, methodology, documentation require-

l ments, and responsibilities for the setpoint program so as to

assure compliance with R.G. 1.105. BEC has agreed that all

l

.

t

18

i

!

!

l _.

. .

safety related B0P instrument loops used to initiate safety-

related actions or required for technical specification

verification will be within the scope of that Desk Instruction.

BEC also indicated that GPC .is preparing calculations .for NSSS

setpoints. 'The: staff believes that ~the corrective action is

appropriate, and performed a followup review of the component

cooling water (CCW) . tank . level setpoint determination and of

the setpoint program in general. BEC calculation X4C1203T02

established the hi/lo control setpoints for maintaining tank

level (via makeup and drain) and the hi/lo alann levels for

operator response to leaks in the system; this~ calculation

determined design basis thermal surge, leak rates, and NPSH

requirements (10-10 level CCW pump trip). Dedicated level

switches positioned according to a BEC level . setting diagram

(LSD) were used to implement control and alarm action. During

the inspection at BEC, it was determined that the installed level

switch elevations did not conform to all of the settings in the

calculation; certain installed settings conformed with LSD

1X5DT0025 Rev. O, but not with Rev.1. Revision 1 of the LSD was

consistent with the approved calculation. Moreover, Revision 2

of the LSD was the current revision, and had changed some of the

calculated settings back.to the installed settings '(i.e.,

installed e'ievations), apparently to avoid rebuilding the level

switch bridle. The staff requested that BEC reconcile the fol-

. lowing discrepancies.in the level settings and determined any

effects on .the system operation:

Function Installed Elev. Calculated Elev.

Hi control 254' -6 1/4 " 253' -9 "

(close valve)*

Lo control 253' -1 1/4 " 253' -2 "

(open valve)

Lo-lo CCW 252' -7 1/4 " 252' -9 "

pump trip

  • This discrepancy was of most interest, since the installed

setpoint is only 11 3/4" from the top of the circular cross-

,

l section tank and is within 1 3/4" of the hi alarm setpoint.

!

4

t

!

! 19

l

. .

BEC addressed these discrepancies as follows:

1) BEC determined that the installed level settings had not

been revised to. agree with the calculation and that this

probably resulted from inadvertently omitting cognizant

reviewers from review of the DCN and LSD revisions.

2) BEC reevaluated calculation X4C1203T02 and determined that

thermal surges using the higher installed setpoints would

still not result in overflow of the surge tank into its

drain tank system during anticipated operating conditions

of the CCW. BEC also determined that there was ample HPSH

margin for the slightly lower "lo-lo" setting.

3) Even if the CCW surge tank were to overflow, the connecting

drain system and drain tank is designed to process and

contain the overflow in an orderly fashion and in accordance

with CCW design requirements.

To determine any generic implications of this discrepancy,

the staff requested a broadness review of all similar surge

tank instrumentation having potential safety significance, ,

to determine if other discrepancies might exist between

installed and calculated settings or elevations. The

auxiliary CCW system and the ESF chilled water systems were

reviewed; the mechanical calculations and the level setting

diagrams were reported to be in complete agreement for these

systems and no field discrepancies were reported. The staff

concluded that the CCW surge tank level setting discrepancies

were of no safety significance for the reasons given above, and

that there did not appear to be any significant generic implica-

tions resulting from this discrepancy.

To support the review of the balance of the setpoint program,

BEC provided a summary of virtually all of the setpoint

calculations within BEC scope. The staff reviewed the

summary, interviewed BEC staff regarding the calculation

bases, and spot checked some calculations. The staff

identified seven variables having setpoints important to

safety that were explicitly listed and that are often in 80P

scope; BEC was asked to identify responsibility for those

setpoints and to provide the calculation or equivalent basis

for any setpoints in BEC scope. The following was determined

for those variables:

20

--

. .

Variable Respons. Remarks

RWST level }[ None

Condensate storage GPC No control setpoint

tank level

Turbine impulse GPC Permissive for RPS

pressure

Turbine autostop BEC BEC calc. X5CP6161

oil pressure

Containment pressure W None

Main FW pump tripped GE BEC doc. CX5DT1101-26C

(hydro. press)

Turbine driven AFW Terry BEC calc. X4C1302V03

pump overspeed

The staff reviewed the BEC calculations and documents above,

and interviewed BEC personnel regarding the methods and as-

sumptions for establishing setpoint tolerances. The staff

concluded that a sound basis had been established by BEC for

setpoint tolerance calculations, input data was well con-

trolled, results were well documented in auditable form,

and BEC personnel appeared to have a good understanding

of the process.

To address the B0P setpoint calculations in GPC scope, the

staff requested the following information from GPC:

1) GPC's engineering procedure for performing setpoint

tolerance calculations.

2) GPC's setpoint tolerance calculation for turbine impulse

pressure.

3) Documentation supporting " engineering judgment".

4) Documentation supporting consideration of environmental

effects on excore flux detector cable and the effect on

channel accuracy.

The staff interviewed cognizant GPC personnel, reviewed the

information submitted by GPC and concluded that GPC's method-

ology appeared to be consistent with WCAP 11269 previously

approved by the staff for VEGP. The documentation submitted

l-

appeared to be complete and consistent. Based on the foregoing

'

review of both BEC's and GPC's setpoint tolerance calculation

l

program, the staff concludes that observation 22-E10 is closed.

l

21

<

.. .. .. - - ____ - ____ _

. .

Observation 22-E16 identified inconsistencies in FSAR Table

10.4.9.5 regarding CWST level alarms; alarms are shown on the

shutdown panels in the. table, which does not agree with design

documentation (there are no alarms on the shutdown panels).

BEC reviewed the design documentation which correctly and

consistently shows these alarms on main control room panels,

and determined that the FSAR was in error; some additional

similar errors were found in the table regarding location and

depiction of various instruments. In no cases were discrepancies

in design information. found. An independent review by the staff

concluded that.the design was consistent and that correction of

these errors in FSAR Section 9.2.6.6 and Table 10.4.9.5 as

proposed by BEC will resolve this observation. Consequently,

this observation is closed..

The remainirg observations in the controls area are not indi-

vidually discussed in this report because they are of lesser

technical significance and wre satisfactorily resolved. In

view of the NRC's review of all observations in the controls

area, the staff concurs with the EA conclusion that the controls

area is technically acceptable. The staff finds this subsection

of the report to be acceptable and no further followup or

evaluation activities are required.

c.6 Section 3.6 - Electrical Design

Section 4.6 - Electrical Design

Section 4.10 - Equipment Qualification

Section 5.F - Electrical Design

Section 5.M6 Module 6, Electrical Equipment

(1) IDR Report

This subsection of the report concludes that the electrical design

area was found to be technically acceptable. Corrective and

preventive actions instituted in response to observations were

adequate to. resolve specific technical concerns. Evaluation of

potential generic or programmatic concerns are given in Section 3.10.

and Appendix F of the IDR Report.

(2) NRC Inspection Results

The IDR electrical design assessment included an examination

by SWEC of approximately: 225 drawings, 30 calculations, 30

specifications, 30 design criteria and over 100 other documents

and correspondence. The IDR team identified 71 observations,

of which 20 were eventually determined invalid. The following

!!RC staff assessment of the observations is provided:

Observation 22-F52 identified that the correct lubricants

were not used for pulling Okonite cables and some Rockbestos

22

.

cables. Subsequent to installation of the cables, approval

from Rockbestos to use Polywater J lubricant was received.

Approval for the use of Polywater J was also received from

Okonite; however, Okonite expressed some concern over the

lcng term effects of the lubricant on the cable insulation.

The Licensee has committed to an evaluation of the long term

effects of Polywater J on the cable insulation as part of the

environmental qualification report. The staff, during the

inspection at BEC in October 1986, reviewed the Okonite Company

letter dated November 27, 1985. This letter informs BEC that

the Okonite Company has review the test data supplied by .

American Polywater, and based on the test data, Okonite j

approves use of "Polywater J" lubricant on class 1E cables.  !

The Team also reviewed American Polywater Co. letter dated

'

June 2,1986 and the Kerite Co. letter dated August 24, 1984. '

These letters conclude that Polywater J lubricant does not

have any deleterious effects on the cables. The staff finds

this resolution acceptable and this observation is closed.

Observation 22-F11 identified that conditions exist wherein

safety-related cable installations in vertical trays and

-

conduits are not adequately supported. This condition can

result in the cables putting excessive loading on terminal

end connections, with the potential for failure _of the

.

'

connections giving rise to safety concerns. The staff was ..

informed during the week of October 20, 1986 that GPC plans

to justify by analysis their current vertical cable support

configuration rather than install additional cable supports.

Review of preliminary supporting documentation provided by

- Bechtel led IE to defer this issue to NRR for evaluation.

This observation is considered closed with reg'ard to Module 22, -

but remains an open licensing issue pending evaluation by NRR. ~

Observation 22-F6 identified that some of the DC power cable

sizing calculations do not take the actual installed configu .

ration (such as: junction boxes, cable length, conduit seal -

assemblies etc.) into account. However. the project has a

cable sizing program to ensure that power cables are reviewed

by the respor.sible engineer for proper sizing after construction

has reported the installed length. Additionally, the project

has committed to the following:

l a. A review of all significant Class 1E DC loads for cable

size consistency between the calculation and the one lines.

b. A review of Train A power cables for consistency between

the one line and EE580 system.

I Correct calculations should include actual lengths, installed

cable size, and an analysis of voltage drop acceptability. The

project has recognized this need and is committed to update

calculation X3CK08 evcry six months. The above planned cor-

rective actions should resolve this action item. To verify

the implementation of these actions, the staff reviewed

23

L

l

v-~ ws. . _ _. _ __ _ _ _ _ _ _ _ _ . _,_ _ . , _ _ , _ ,_,

- ______ ___

,.

.

calculation X3Cr.08 Revision 5 as a sample and noted that the

calculation.now uses installed length of cable in place of

designed length. The installed length is taken from the

EE-580 cable schedule which identifies installed cables by

the letters "cc" (construction completed). The staff verified

this fact from EE-580 dated 5/13/86. As an example, two

cables, LADLCA and LADLCB with design length of 43' and 51'

have "cc" value of.36'and 54', respectively. The staff veri-

fied that the 54' value was used for calculation of the

voltage drop. Cable sizing and voltage drop calculations

for motor feeder cables for valves HV-5120 and HV-5122 were

reviewed by the staff. The staff noted that the calculation

now accounts for length.and wire sizes, for electric conduit

seal assemblies, and for junction boxes. The staff found all

of the above actions satisfactory. This observation is closed.

Observation 22-F17 concerned whether analyses exist to support

the requirements of CMEB 9.5-1 for separation of different

safe-shutdown Trains of Electrical Cable within the same fire

area. The staff found that BEC had completed the Appendix 'R'

analysis and this analysis resulted in the following:

a. Approximately 33 cases of raceways require application of

3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> _ fire wrap. Three out of 33 raceways carry power

feed and the remaining 30 are utilized for control or

instrumentation applications. The power feed raceways

identified were 1BE311RM156,1BE311TLAM and 1BE304RS162.

The team noted that BEC performed an analysis for derating

of power feed cables for the fire wrap. (Ref: BB-51481,

file No. X3BE01). The derating factor used was taken from

the vendor's test report No. 82-5-355 F dated July 1982.

b. In one instance, a concrete wall was constructed to

redefine and separate fire zones 14C and 14D on

elevation 'C' as shown on drawing #AX4DJ8011.

The above actions by BEC are acceptable to the staff and

this observation is closed.

Observation 22-F34 concerned the validity of the 480 volt

cable sizing calculations. The existing calculation

apparently:

a. Contains an inconsistency between the conductor

temperature used and the design crit:ria.

b. Does not account for additional cable length due to

twisting.

c. Does not take accident ambient temperature into account.

24

._

.

The staff reviewed calculation X3CK06 Revision 6 for high

conductor temperature analysis. BEC used 81 C as a maximum

temperature in 2-3 such cases. Using the correction factor

for 81 C results in an additional voltage drop of 1.019%.

This calculation also addresses the effects of high ambient

temperature during LOCA conditions on voltage drop. Calculation

X3CA03-1 shows pre-LOCA worst case voltage drop on bus 1ABA as

0.9428 PU and during LOCA as 0.8653 PU, respectively. The NRC

team noted from calculation X3CK05 Rev.7, and calculation X3CK06

Rev.6, that terminal voltages using worst case (high conductor

temperature, LOCA ambient temperature and degraded bus voltages)

at motor terminals of motors located inside the containment

(containment cooler unit and purge unit fans) were within the

design limits. The staff also noted from calculation X3CK06

that an allowance has been added for twisted conductor cables.

Calculation of this allowance was done in accordance with the

vendor's method described in letter AX3AJ01-16-1 dated

November 12, 1986. All of the above actions by BEC are

acceptable to the NRC team and resolves this concern. This

observation is closed.

Observation 22-F35 indicates that design criteria used for

ampacity calculations 60 not address the deratings required

for punched bottom trays vs cable in air, covers or solid

bottom tray fittings. The project committed to revise design

documents so that maintained spaced cables in solid bottom

trays will be sized on the basis of the more conservative

standard, ICEA-P-54-440; to provide 25% uprating in ampacity

across the board for all the cables; to provide an engineering

evaluation for each instance where nonventilated covers are

used to evaluate if the 25% margin has been encroached due

to factors such as degraded voltage; and to revise the FSAR

design criteria and calculations to indicate the planned case-

by-case reduction from the committed generic allowance of 25%.

The staff noted that BEC has added the 25% uprating for ampacity

requirements of all the cables and an additional 10% derating

used for fire stops for trays without covers. For trays which

are covered, a derating factor of 27% is being used. This factor

resulted from testing done at San Onofre station by BEC. The

staff noted this has been referenced as note #10 on page 6 of

calculation X3CK01, reference 4, BEC IOM-E 2.6.4/LS 301 dated

10/22/84. The staff found that for solid bottom trays with

covers, ICEA-P54-440 values of ampacity are being used and

design criteria DC-1809 ampacity tables have been revised to

this effect. BEC has conducted analysis of cases where

encroachment of the specified generic margin has occurred to

verify that the affected calculations are revised. In view

of the above, this item is closed.

Observation 22-F37 concerned the adequacy of the DC system

design due to numerous findings related to first minute /last

minute voltages at the battery system and cable lengths that

25

. .

did not consider actual installed lengths, junction boxes,

and electric conduit seal assemblies. The team noted that i

J

BEC now uses the installed lengths.of cable and accounts for

junction boxes and electric conduit seal assemblies in

voltage drop calculations (see the resolution to observation

F06). The staff reviewed voltage drop calculations, battery

vendor's test data, and equipment qualification reports for one

DC operated valve and for a control' panel of the auxiliary

feedwater turbine. The team noted that the first minute voltages.

at batteries A,B,C were 116.23, 116.23 and 115.05 volts. If

these values were used for voltage drop calculations, the voltage

at DC valve HV-5120 will be 99.5 V, which is lower than the 100 V

for which this valve has been qualified. BEC stated that since

the vendor tests were conducted at 55 F and normal ambient in

the battery room will be at 70*F, the adjusted voltage values

for batteries A,B,and C will be 117.41, 117.41 and 115.93 V.

Using this voltage, starting voltage at valve HV-5120 will be

100.39 V (0.39 V above 100 V). The team found the last minute

voltages at batteries A,B were 108.78 V, 108.78 V and voltage

at battery panel C was 107.0V. This reflects 90.8 Y (qualified

for 90 V) at the PORV and 105.08 V (minimum required voltage is

105 V) at the AFW turbine driven pump control panel. These values

are marginal but since there is no specific requirement of a

minimum margin, these values are accepted by the staff and this

observation is closed.

The remaining observations in the electrical area are not indi-

vidually discussed in this report since they were of less

technical significance and were satisfactorily resolved. In

view of the review of all observations, the staff concurs with

the EA conclusion that the electrical design is technically

acceptable. This subsection of the report is acceptable and

no further followup or evaluation is required.

c.7 Section 3.7 - System Design

Section 3.8 - HVAC System Design

Section 3.9 - HVAC Duct Design

Section 4.7 - System Design

Section 4.8 - HVAC Sy: tem Design

Section 4.9 - HVAC Duct Design

Section 5.G - System Design & HVAC System Design

Section 5.M4 Module 16, NSSS

'

(1) IDR Report

i

In these subsections, SWEC concluded that the plant design

was technically acceptable and was in accordance with

licensing commitments and code requirements, with exception

of the specific observations noted.

l

26

l

!

.

(2) NRC Inspection Results

The IDR reviews included examination of approximately 85

drawings, 70 calculations, 24 specifications, 27 design

criteria, and over 100 other documents such as computer

reports, correspondence, procedures, vendor documents,

and change documents. As a result of this review, 27

valid observations were identified in the systems design

area. In addition, 5 valid observations were identified

in HVAC system design and 4 valid observations in HVAC' duct

design. The following NRC staff assessment of the observations

is provided:

Observations 4-19 and 16-3 identified that protection had not

been provided on the low design pressure AFW and SIS pump

suction piping from potential overpressure due to back

leakage through the discharge check valve of a nonoperating

pump. Review of other systems with a potential for similar

over pressure through back leakage revealed no other

instar:ces where protection was required. The potential for

overpressure of the AFW and SIS systems was corrected by the

installation of suction piping relief valves. The staff

reviewed the documentation associated with these observations

(including the change control packages for installation of

the relief valves) and concluded that appropriate action had

been taken. Further, the staff noted that the conditions

necessary to cause the overpressure do not exist when these

systems are relied upon to perform their safety functions,

since all system pumps would be operating at that time. These

observations are closed.

Observations 4-24 and 4-25 dealt with the sizing of the

Component Cooling Water (CCW) surge tank. The project's

initial responses were that this surge tank was considerably

oversized and that substantial margin existed in spite of the

concerns identified. Subsequently, it was discovered that

the complete surge tank was not higher than all of the system

piping, rendering a portion of the tank unavailable as a

surge volume. With this further reduction in tank margin,

the staff became concerned with certain assumptions made in

the sizing calculations. During the inspecticn at BEC

headquarters the week of October 6, the staff evaluated all

aspects of the design of this tank. Calculations X4C1203S02

and X4C1203T02 were reviewed and discussed with BEC. As a

result of this review, the staff concluded that the design

assumptions were sufficiently conservative and that the tank

design was in accordance with commitments and regulatory

requirements. This observation is closed.

Observations 16-1 and 16-2 identified instances where the

safety injection / residual heat removal systems could be

isolated from their over pressure protection paths should

27

. . . . -- _. - - . . - _. . . . .

- -

, .

.  ;~

.

certain manual valves be shut. The design was modiMed to

'.' provide unblocked relief paths. . Review of relief paths in

'

other' safety-related systemsLrevealed no similar instances

where relief paths.could be blocked. The staff reviewed

,

-

documentation associated with these observaticas and deter-

mined that appropriate action had been taken. .These observa-

tions-are closed.

,

Observation 22-G02 dealt with the calculation of AFW turbine

driven pump room ventilation by natural convection. BEC

agreed that the present duct work arrangement differed from

that of the calculation but asserted that the overall effect

on the calculation would be ir.significanti BEC agreed to .

revise the calculation following the test to measure flows,

temperatures, and heat loads committed to in the answer to

,

- NRC question 410.54. During the NRC's inspection at BEC in

October 1986, the staff reviewed the test results and the -

!

subsequently revised calculation (X4C21E9V01). The test

l

shoved that the natural convection air flow was considerably

.

.

less than originally predicted (1200 CFM vice 3800 CFM) but -

that the resulting peak temperature (extrapolated to peak

outside design temperature of 98*F) exceeded-the limit for

the space by 2 F (122'F vice 120 F). Initial reviews C

'

indicated that the 2 F increase in peak temperature had no '

-

'

impact on installed equipment. Further, the test conditions '

were quite conservative in that certain steam leaks during

the test added considerable heat load to the room. Since >

modeling of the natural circulation flow is complex and since

the confirmatory test was committed to prior to the IDR, the

'

staff considers this matter to be part of the: normal design

process. Confirmation by the Applicant inia letter from

D. P. Rice to Region 11 dated November 20, 1986 verified that

the equipment was qualified for a 2 F increase in peak

I

temperature and that appropriate documentation, including

appropriate FSAR sections, have been updated to reflect

extrapolated test results. This observation is closed.

i

Observation 22-GC5 involved conditions where spot cooling was

relied upon for the self cooling-of certain HVAC cooler

motors but that duct layout drawings did not direct adequate

air flow. As a result of this observation, a review of all

spot cooling applications was performed. Two instances were

identified where spot cooling applicatiens d'd not meet the

design intent. Design changes were initiated to adequately

l

account for spot t.ooling requirements in these cases. The 2

l staff confirmed the design changes by reviewing Des)gn Change -

~

,

Notices H-346-M and H-347-M during t.he inspection of BEC in s

i

L October 1986. Stbsequent calculatiohs by BEC indicated that g i s

28

e

,,.,._m---

---

,-,-- y p _,y .. . , _. .,, 7 ,%,_y._, .. ., , , , _ , , , , ,.,,,,,,_,m_r

h '

W

.

l'

.

. ^' h I

  1. design' temperatures would not have been exceeded, even with-

l 13 - .

out the design changes. This observation is closed.

  1. d -

-

M 3

Lu

,#' ~'f*

!

~ L .3 Observation 22-G14. stated-that.it was not evident that the

N" calculation con' firming AFW process design (X4C1302S08) had

y performed single failure) analyses for accidents other than

L

.the main feedline rupture. The observation questioned.whether

!. A single failure andysts had been performed for other potential

MF

~

accidents such as hain' steam line rupture and station blackout

'T, '

, ' with loss of normal feedwater. The project responded that

'

single failures had been properly. considered for the conditions

  • analyzed in.the cited calculation and that system perforirance

had been evaluated for the worst single failures which could

maximize or minimize system flow.- Subsequent review by the

IDR determined this to be a case of undocumented engineering

Judpent. After reviewirig the bases for the judgments, the

'IDR concurred that single failure had been considered for

-  % worst"casciondi tions. Similar review of single failure

1:

'

u considerations by s the staff also resultad in' a concurrenct

U ,

~ y' Ctha(d.:: close ingle failure criteria had been met. This observation is

'

y

.

,

c

,L$- -

-' '? Otse'rvations 22-G171alon'g with 4-14 and 4-17, were related

5,' @ to concerns" associated with AFW system piping design pressure.

g. N, - Specifically, questions were raised'as _ to whether or not the

i '(

'

piping on the discharge side of the turbine driven AFW pump

."

could be pressurized in'ekces's of system design pressure under

'

a turbine over speed con _dition. As a result of these bbser-

vations, the design pressure of the piping between the turbine

V 1

driven AFW pump discharde and the restriction orifices was

'Mu@ . ,

increased from 1800 ps'ig tc 1975 psig. The problem wasdimited

-

  1. ,

4 to the AFW system which.is the only safety-related system with a

,

'

? ' turbine pump which;is subject to an over speed condition. With

T['- regard to the piping between the restriction orifices and the

stop check isolation valves, BEC asserted that this piping was

( ,~ [

--

,

not subjected tc#e over pressure condition since the isolation

t va'.ves are locked open.3 Further the VEGp commitment that normally

locbd open valves will not be manually c70 sad during system

- teiting of the AFW system was proposed 'in- FSAR Amendment 13 -

,

-(questioc'0420.32) and accepted by the' NRC in Section 7.3.3.7

'

'

cf.:the NE's SER of June 1986. In view of'the above, the staff

! codsiders the action taken to resolve this observation to be

! O[- 9ppropriate and this observation is closed.,,

qy , , ,
1

The remaining observations in the system design, HVAC design,

l h, and HVAC duct design areas are not individually discussed

j '- N because they were of lesser technical significance and were

d.. b satisfactorily resolved and closed out.

-

i

m

In view of the technical discussicas @1ove, the NRC staff

I

^

concurswiththeIDRconclusions9thatithedesignoftheplant

'

is technically adequate. With r'egard tog hardware changes,

' '

! \

!

d 4 -

29 N

j )-  %

1! ,

J

1

>!

2 - -- a : ~ _- . - - --. --

.

such as addition of suction side relief valves to prevent

over pressure or the increase in AFW turbine driven discharge

piping design pressure, the implications of these changes

relative to the overall design has been discussed in the

individual observations. With regard to other potential

generic concerns, these items are discussed in subsection

c.8 of this report. The staff finds this subsection of the

report to be acceptable. No followup action or evaluation

is required.

c.8 Section 3.10 - Evaluation of Generic Concerns

Appendix F - Evaluation of Generic Concerns

(1) IDR Report

In order to assess the collective significance of IDR

' observations, two separate analyses were performed. The

' first involved categorization of SBTA observations into

specific areas of weakness while the second included a

cumulative evaluation of IDR and other Readiness Review

observations related to the scope of the SBTA. From these

analyses, eight generic concerns were identified and

analyzed. The eight concerns are listed below:

Item Potential Concern

Finalization Programs Existing documentation did not clearly

indicate that the programs would correct

and prevent deficiencies of the type

noted in individual observations.

Calculations This concern was related to 1) errors

existing in project calculations

2) completeness and implementation of

guidelines for performing and checking

calculations 3) formalization of

'

.

calculation update requirements 4)

documentation of cumulative use of

design margins and 5) the degree of

implementation of ANSI N45.2.11

requirements.

Use of NON-VEGP Data Use of NON-VEGP specific technical

data may not have been properly

evaluated and documented for

applicability.

Piping Design Concerns were identified relative to

1) the use of stress intensification

factors 2) technical and procedural

noncompliance 3) documentation of

design and operating modes and

4) control and completion of outstanding

technical issues.

30

- -

- - . - -- -- .

-

. .

Pipe Support Design Concerns were identified relative to

1) technical and administrative adequacy

of support calculations and 2) control

and completion of outstanding technical

issues such as load changes and support

location changes.

Hazards Program Concerns were identified relative to

1) the adequacy of documentation

2) adequacy of intradiscipline interface

and design change control 3) adequacy

of project procedures and 4) use of

inappropriate plant layout information.

Electrical Design Concerns were identified relative to

1) inconsistencies between electrical

design documents 2) the adequacy and

accuracy of the electrical design

criteria and 3) the adequacy of DC

system design.

BEC/ Westinghouse Concerns were identified relative to

Interface 1) over pressure protection design

2) piping system desigr. load

verification and 3) handling of NSSS

design information.

Following a detailed assessment of each of these items in

Section 3.10 and Appendix F, the IDR concluded:

" Based on the detailed assessments above, the IDR team

concludes that with comple"on of the required corrective

actions, and program enhc :1ments being implemented by the

project, all identified potential generic / programmatic

concerns have been adequately addressed."

(2) NRC Inspection Results

Based upon the large number of staff inspections of the VEGP

Readiness Review Program associated with plant design and the

design process, as detailed in this report, particularly the

inspection of corrective and preventive actions at BEC

1

headquarters from October 6-9, 1986 (which directly evaluated

i

the generic concerns), the NRC staff concurs with the IDR

l

assessment that the generic concerns have been adequately

'

addressed. The staff finds this subsection of the report to

be acceptable. No followup activities or further evaluation

is required. Specific staff comments associated with each of

the potential generic concerns are provided below:

!

31

,

'

- - -

_.

.

Item Comment

Finalization Programs Enhancements to the Finalization Programs

resulting from IDR observations have

resolved potential concerns that these

programs might not adequately address

the observations of the IDR. When

completed, the Finalization Programs

will provide additional assurance

that the design of VEGP is in accordance with

commitments.

Calculations During the course of several . inspections,

the staff has independently reviewed a

number of calculations in all technical

disciplines. The number and magnitude

of problems identified by the IDR and

the NRC are not unusual for a design

project of this magnitude. The staff

has-confidence that the calculations

adequately support the plant design.

Use of NON-VEGP Use of NON-VEGP data was principally

Data applied as corroborative evidence in

support of engineering judgments. In

some cases, additional information was

required to substantiate the use of

this data for the VEGP. In no case

did hardware changes result solely

from the application of NON-VEGP data.

Finally, a broadness review indicated

that NON-VEGP data was not extensively

used.

Piping Design During the course of the inspections,

design criteria documents and a large

number of calculations were reviewed by

the staff. Based on these reviews, the

staff concurs that these generic concerns

have been adequately addressed.

Pipe Support Design During the various NRC 1nspections, a

large number of pipe support calculations

were reviewed. With minor exceptions

the calculations were ad;teate and

outstanding technical issues were

adequately controlled.

Hazards Program At the time of the IDR, the VEGP Hazards

Program, both from the standpoint of

work accomplished and documentation

available, was further advanced than

typical hazards programs at a similar

stage of design. The enhancements

32

-

. - . - - . . -- _. -- .- . . .- ..

. .

1 made as a result of the IDR, as

subsequently verified by the staff, 1

substantially improved the-program in

- . specific areas. The final result is

a comprehensive, thorough, and well

,

documented program which achieves

design objectives. The staff concurs

!- with the IDR conclusion that a generic

program breakdown did not occur. With

.

regard to the failure to postulate

longitudinal breaks (observation 22-B01),

'

the hardware changes resulting from '

this observation (relocation of some

,

electrical conduit) provide an additional

measure of conservatism to the design of-

the plant. The safety implications of

plant operation without having relocated

.

'

.this conduit are not significant.

Electrical Design The staff's review of the electrical

area indicated specific weaknesses

which were corrected, but not a

,- programmatic breakdown of the design

'

process. Although there was generally

little margin in the DC system design,

the basic requirements were met and.

i the overall electrical design is

i considered adequate.

[ BEC/ Westinghouse Root causes of these discrepancies

Interface involved interpretation of code

requirements, inattention to detail

when transferring data, and designs-

2 based on anticipated criteria changes,

i Specific corrective actions were

undertaken to remedy these root causes.

The staff concurs.that no programmatic

i breakdown occurred and that a proper.

and controlled interface exists.

'

d. Section 4 - Review Description

. (1) IDR Report

The technical content of this section has been discussed in

the appropriate subsection of paragraph 3.c, above.

~

(2) NRC Inspection Results

!

Inspection results are given in paragraph 3.c,

  • above.

.

1

33

i

i

1 ,

._. r - , -. , _ . - . . . . , . . , , , . , , . .. .. - _ _ _ - , _ _ . . _ _ - _ _ . _ , . _ . . - _ - - - . - _ _ , . -__-

.

.

e. Section 5 - Review Observations, Responses, Assessments

(1) IDR Report

The technical content of this section has been discussed

in the appropriate subsection of paragraph 3.c, above.

(2) NRC Inspection Results

Inspection results are given in paragraph 3.c, above.

f. Appendices

(1) IDR Report

The report appendices provide either (1) background

information (e.g. the review plan, personnel contacted),

(2) supplementary information (e.g. documents reviewed,

action commitment summary), or (3) further review

analysis (e.g. Appendix F - Generic / Programmatic Project

Assessment).

(2) NRC Inspection Results

Information in the appendices was reviewed either for

background information or with the corresponding

subsection of Section 3 (discussed in paragraph 3.c,

above). No followup activities or evaluation of these

appendices are required.

4. Statement of Module Acceptability

In paragraph 3 of this report (NRC Staff Evaluations), each section of

the IDR Report (Readiness Review Module 22) was technically evaluated.

In each instance, the specific sections of the IDR reoort were found

acceptable to the NRC staff, for reasons enumerated in the individual

subparagraphs. Taking each of these subparagraphs collectively, the NRC

finds Module 22 to be acceptable. No followup activities or evaluations

are required.

In view of the results of Module 22 and the independent assessments of

the structural design, (Modules 1, 8, and 13), both the analysis of

individual observations and the evaluation of potential generic concerns,

the NRC concludes that a technically adequate design process has been

successfully implemented at VEGP. The Applicant's Readiness Review

Program has provided additional assurances that the design of VEGP is in

accordance with licensing commitments and regulatory requirements.

Further, the PRC's direct monitoring of the IDR provides additional

credibility to the validity of the program results. No further pre-

license design review activities are considered necessary.

34

/

. .

List of Persons Contacted

Throughout the course of the five inspections conducted by the NRC in monitoring

Module 22, a large number of personnel were contacted from each of four organi-

zations: Georgia Power Company, Stone & Webster Engineering Corporation, Bechtel

Engineering Corporation, and Southern Company Services. Individuals contacted

during a specific inspection are identified in the report of that inspection.

The report numbers are identified in Section 2 of this report.

The following is a summary of key individuals of each organization contacted by

the NRC:

Georgia Power Co./ Southern Company Services

Batum, 0. Deputy:to V.P. Engineer

Foster, D. V.P. Project Support

Hayes, C. Vogtle QA Manager '

McManus, R. Assistant Project Const. Manager

Ramsey, W. Manager, Readiness Review

Read, D. General Manager, QA

Rice, P. V.P. Project Engineering

Bechtel Engineering Corp.

Beer, M. Westinghouse Technical Assistant

Blasingame, J. Manager of Engineering

Capito, D. Piping Group Supervisor

Carpa, P. Chief Engineer, Westec Power Div.

Cereghino, S. Nuclear Group Supervisor

Freid, S. Assistant Chief Mech / Nuclear

Johnson, W. Control Systems Group Supervisor

'

Malcolm, M. Deputy Project Engineering Manager

Marsh, F. Project Engineering Manager

McDaniel, P. Mechanical Deputy Group Supervisor

Morrow, D. Electrical Group Supervisor

Sanders, A. Assistant Project Engineer

Smith, R. Electrical RR Coordinator

Strohman, D. Project QA Engineer

Walvekar, K. Mechanical Group Supervisor

Stone & Webster Engineering Corp.

Allen, J. Project Manager

Bushnell, G. Hazards Reviewer, IDR

Eifert, W. Chief Engineer, EA

Frank, S. Mechanical Systems Reviewer

>

Gardel, W. Electrical Reviewer

Genosi, A. Engineering Assurance / Module 4

King, D. Engineering Manager

Lockaby, J. Duct & Pipe Supports Reviewer

Mathur, R. Structural Reviewer

Mullen, C. Controls Reviewer

Stamm, S. Tech. Manager - IDR

Tsai, C. Pipe Stress Reviewer

35

1

.

Acronyms

.The following acronyms are used throughout this report:

AFW Auxiliary Feedwater System

ANSI American National Standards Institute

ASME American Society of Mechanical Engineers

BEC Bechtel Engineering Corporation

B0P- Balance of Plant

CCW Component Cooling Water

CWST Condensate Water Storage Tank

DC Direct Current

EA Engineering Assurance

FCR Field Change Request

FSAR Final Safety Analysis Report

GPC Georgia Power Company

HVAC Heating,-Ventilating & Air Conditioning

IDR Independent Design Review

IDVP Independent Design Verification Programs

IE NRC Office of. Inspection and Enforcement

LOCA Loss of Coolant Accident

NRC Nuclear Regulatory Commission

NRR NRC Office of Nuclear Reactor Regulation

NSSS Nuclear Steam Supply System

P&ID Piping & Instrument Diagram

PORV Power Operated Relief Valve

PSDM Pipe Support Design Manual

PVRC Pressure Vessel Research Council

RCL Reactor Coolant Loop

RR Readiness Review

SAR Safety Analysis Report

SBTA System Based Technical Assessnent

SER Safety Evaluation Report

SIS Safety Injection System

SSE Safe Shutdown Earthquake

SWEC Stone & Webster Engineering Corp.

VEGP Vogtle Electric Generating Plant

1

36