ML20132F708

Implementation Insp Rept 50-498/85-09 at S&W,Boston,Ma on 850423-26.Major Areas Inspected:Engineering Assurance Program.Program Capable of Evaluating Adequacy of Design & Effectiveness of Design Process for Sys Being Reviewed

ML20132F708
Person / Time
Site:	South Texas
Issue date:	06/25/1985
From:	Imbro E, Milhoan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
Shared Package
ML20132F683	List: ML20132F680 ML20132F708
References
50-498-85-09, 50-498-85-9, NUDOCS 8507190018
Download: ML20132F708 (9)

See also: IR 05000498/1985009

Text

. .

,

U. S. NUCLEAR REGULATORY COMMISSION

-

1

0FFICE OF INSPECTION AND ENFORCEMENT

Division of Quality Assurance, Vendor, and

Technical Training Center Programs

Quality Assurance Branch

Report No.: 50-498/85-09

Docket No.: 50-498

Licensee: Houston Light & Power Company

Facility Name: South Texas Project Unit 1

Inspection At: Stone and Webster Engineering Corporation, Boston, MA

Inspection Conducted: April 23-26, 1985

Inspection Team Members:

Team Leader: G. Imbro, Senior Inspection Specialist, IE

Mechanical Systems: T. Delgaizo, Consultant, WESTEC Services

G. Overbeck, Consultant, WESTEC Services

Mechanical Components: R. Parkhill, Inspection Speciclist, IE

S. Gula, Consultant, Harstead Engineering

Electrical /I&C: G. Morris, Consultant, WESTEC Services

Civil / Structural: G. Harstead, Consultant, Harstead Engineering

'

.

f 7 LA&:+

Eugene Imbro

4/a//pg

Date

Team Leader, IE

ci W4 b'

~

Approved by: L ec 0 MYd' $

ames L. Milhoan Date

ection Chief

uality Assurance Branch, IE

.

e

'.

8507190018 8507

PDR ADOCK 050 pg 8

O

1

. .

I

SOUTH TEXAS PROJECT - UNIT 1

Implementation Inspection of Engineering Assurance Program

April 23 through 26, 1985

1. Background

On March 1, 1984, representatives of the Houston Lighting and Power Company

(HL&P) presented to the Quality Assurance Branch of the Office of Inspection

and Enforcement, USNRC, the details of the Engineering Assurance Program (EAP)

being conducted on the South Texas Project (STP). As a result of this meeting,

and additional information provided by HL&P, the NRC determined that the

Engineering Assurance Program, if properly implemented, could provide the

additional assurances of design adequacy normally provided by an Independent

Design Verification Program (IDVP). Formal acceptance of the EAP as a substi-

tute for an IDVP was provided via an August 20, 1984, letter to HL&P.

Since the STP Engineering Assurance Program is an on going program, the NRC

decided to monitor the effectiveness of the program in three phases:

(1) implementation of the program plan and procedures, (2) review and evaluation

of audit results, and (3) follow-up of corrective action. This inspection

report addresses the first phase of the NRC's monitoring program. In particular,

the NRC Inspection Team evaluated the depth of review being performed by the

Engineering Assurance Contractor [ Stone and Webster Engineering Corporation

(SWEC)] for Independent Technical Assessments (ITA) 85-1 (Control Room HVAC),

85-2 (Component Cooling Water System) and 85-3 (Off-site AC Power Supply

Systems). ITA 85-1 was essentially complete (although not finalized and

published), 85-2 was in the early stages of review and 85-3 had only scope and

document review plans available.

2. Purpose

The purpose of the inspection was to establish that the independent technical

assessments were being conducted in accordance with approved program plans and

were in sufficient technical depth to evaluate the adequacy of the design and

design process at the South Texas Project.

3. NRC Inspection Team

Assignment Name, Position

Team Leader E. Imbro, Senior Inspection Specialist, IE

Mechanical Systems T. DelGaizo, Consultant, WESTEC Services

G. Overbeck, Consultant, WESTEC Services

Mechanical Components R. Parkhill, Inspection Specialist, IE

S. Gula, Consultant, Harstead Engineering

Electrical /I&C G. Morris, Consultant, WESTEC Services

Civil / Structural H. Harstead, Consultant, Harstead Engineering

• J. Milhoan, Section Chief, Quality

Assurance Branch, IE -

• Attended Exit Meeting

_ _ _ _ _ _

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

-

. .

,

4. Personnel Contacted

.

A large number of Applicant and Engineering Assurance Contractor

personnel were contacted during the inspection. The following is a brief

list of key personnel contacted:

.

Name Organization Position

R. Frazar HL&P EA Program Manager

S. Basu HL&P EA Program Staff

M. Chakravorty HL&P EA Program Staff

P. Garfinkel SWEC VP & Sr. Eng. Manager

W. Eifert SWEC Chief Engineer, EA

A. Banerjee SWEC STP EA Project Manager

5. General Conclusions

There was evidence of substantial review of design calculations, piping, and

instrument diagrams, electrical diagrams, design specifications, and other

design documents. In view of this review effort, and the personrel interviewed

(both HL&P and SWEC) and the number and type of deficiencies being uncovered

by the Engineering Assurance Program, the NRC Inspection Team is satisfied,

assuming satisfactory resolution of the items in this inspection report, that

the Engineering Assurance Program for South Texas Project is capable of evaluating

the adequacy of design and effectiveness of the design process for the systems

being reviewed.

6. Specific Comments

Specific comments on a technical discipline basis are included in the

following attachment.

.

i

i

-_ __

. - _ . . . _ _ . _ _

• *

.

ATTACHMENT

SPECIFIC COMMENTS

I. Mechanical Systems / Power Engineering

In the mechanical discipline, the NRC Team found the depth of review consistent

with that of an IDI or IDVP. The Team also found the SWEC reviewers to be

highly qualified technically and familiar with the technical issues and the

concerns expressed by the NRC Team. The following comments are considered

noteworthy:

1. The Team found that the Control Room HVAC Mechanical Design Documents

provided by BEC to SWEC were recently revised and updated just prior to

commencement of the review effort. However, the team observed that in

review topic 85-2, Component Cooling Water System, this was not the case.

The adequacy of the method by which the EAP selects review topics and is

assured that these topics are representative of the design process remains

an open item.

2. SWEC Document Review Plans for four calculations were reviewed. From

this review, the Team was concerned that SWEC was not systematically

verifying design inputs and assumptions. The adequacy of the verification

process remains an open item. Examples to support this concern are

presented below,

a. The SWEC reviewer of HVAC calculations did not verify the

correctness of references identified in the design calculations as

sources of design input and therefore has not confirmed the

traceability of design input through to the final design. For

example, calculation SV119VQ1023 identified a design criteria

document as a source of temperature inputs; however, this document

was not in SWEC's set of review documents (design criteria document

SV019VQ1031 Rev. 1). The Team was informed that the outside design

temperature conditions were verified by the SWEC reviewer through

.

use of the FSAR.

b. In review of calculation 5Z1492Q1000, the SWEC reviewer did not use

referenced drawings to confirm design inputs. For the length of

duct dimensions used in the calculation, the SWEC review used an HVAC

arrangement drawing instead of an architectural drawing. The

required information was not dimensioned and the reviewer scaled the

required information from a half size reduction. The referenced

drawing was not in SWEC's set of review documents.

c. The Team also observed instances where the referenced documents no

longer contained the needed design information. The team found this

particularly true of specification references. For example, in

calculating the heat load from an air handling unit in Room 307 (CR

AHU 3V111VAH009) input values for horsepower and motor efficiency

were used and a reference made to the procurement specification for

the air handling units. The data sheet for this air handling unit

did not specify the motor efficiency or horsepower (typically this

is vendor supplied data). The Team was informed that vendor data

was obtained to confirm the data; however, a comment was not

provided on the document review sheet.

l

. .

,

d. The SWEC reviewer did not consistently identify assumptions and

-

inputs that required confirmation at a later date. For example,

design criteria #5 of Calculation 3V110MC5148 was not identified as

an input that needed confirmation at a later date. The design

criteria incorporated design input obtained from BEC's control

group. For Room 202, the Team found that many of the inputs came

from verbal communications, manufacturer's proposals, and

engineering estimates. In another example, the reviewer did not

identify that the location of radiation detectors in calculation

3V111MC5857 was based on preliminary information.

3. Regarding technical matters, the Team has comments concerning two issues:

a. The first issue involves the completeness of the verification performed

by SWEC to confirm the adequacy of the Control Room HVAC system with

respect to the single failure criterion. Specifically, the Team

found that the extent of the single failure review was limited to a

review of document 4RA369NQ1004. This document is a generic design

criteria document and is not specific to the Control Room HVAC

system. The Team observed that the same document is to be reviewed

for the component cooling water system. The ability of each system

reviewed to meet the single failure criterion must be individually

assessed to fulfil the intended audit scope. The adequacy of audits

with respect to the single failure criterion remains an open item.

b. The second issue involves an assumption used to arrive at the heat

load from energized cable in cable trays which needs further technical

justification to confirm its adequacy. Specifically, in calculation

3V110MC5148, a design input was used for heat load based upon an

assumption that at any time, only 60% of all cables in cable trays

are energized. The Team determined that the SWEC reviewer accepted

this assumption based upon his engineering judgment and a technical

approach described in an IEEE paper. The Team believes that the

auditors should have requested the project organization to provide

justification for applicability of the approach to this plant.

The use of the above assumption remains an open item.

4. The following are additional items which were observed throughout the

course of the inspection or provide additional details relative to the

more general comments provided above.

a. The closure time of the isolation dampers for the Control Room HVAC

system was based upon the procurement specification. The SWEC

reviewer requested additional information through RFI-1 and received

Damper Data Sheets 242 and 245. The data sheets were a copy from

Revision 1 of the specification, not from the Material Requisition.

The specification indicated that Appendix C (the data sheets) had

been deleted from the specification and made reference to Section 3

of the Material Requisition. The adequacy of the verification of this

design input remains an open item.

b. There was an undocumented assumption in Calculation 3V111MC5857

regarding the location of the radiation detectors. In discussions

with BEC, HL&P, and SWEC, it was learned that the detectors will be

located at a later time and the location for purposes of the calculation

-2-

. .

,

is a best estimate of the final location. The assumption regarding

.

the location of the radiation detectors in the calculation remains an

open item.

c. Reference 7 of Calculation SV019VQ1031, Rev. 1 could not be located

in the SWEC documentation. Apparently, the SWEC reviewer relied

upon FSAR information to verify the numbers in the calculation.

Verification of the calculational input remains an open item.

d. Design Criteria Item 4 states that heat gain from electrical equipment,

cable trays, and lighting assumes that at any time only 60% of all

trays (Class 1E and Class non-1E) are energized. This assumption I

does not appear to have been confirmed by BEC. The assumption is

based upon another assumption that during an emergency condition, a

loss of offsite power condition exists and that all non-1E loads are

lost. This may not be the case. The Team further believes that

these assumptions will not have significant impact on the sizing of

equipment in the Control Room; however, they could be significant in

the design of Switchgear Room cooling equipment. It appears that

these assumptions are used elsewhere in the plant including Switchgear

Rooms. The justification of these assumptions for the aforementioned

applications remains an open item.

e. In calculating heat loads from the air handling unit in Room 307

(3V111VAH009), input values for horsepower and motor efficiency were

referenced to the procurement specification for the unit. The data

sheet did not specify these values. Apparently, these values were

estimates (50 HP and 89% efficiency) which were not properly documented.

The justification of these assumptions remains an open item.

II. Mechanical Components / Engineering Mechanics

In the area of engineering mechanics, the NRC Team found the depth of review

consistent with that of an IDI or IDVP. The Team also found the SWEC

reviewers to be highly qualified technically and familiar with the technical

issues and concerns expressed by the NRC Team. Since the SWEC mechanical

components review of 85-2 had not yet progressed to completing the checklists,

the NRC Team inspected SWEC's depth of review associated with 85-3 " Stress

Analysis of the RHR/SI System" and 83-4 " Pipe Support Design of the RHR/SI

System." The following comments are considered noteworthy.

1. Regarding the structural frame analysis program, BISEPS, which is used

extensively in the design of pipe support frames, it did not appear that

SWEC reviewers familiarized themselves with the inputs and outputs of

this program by referring to the users manual. Specifically, the SWEC

reviewer was not able to explain to the satisfaction of the Team that he

understood how Beta angle was input. Your verification of the adequacy of

this program for the application remains an open item. This verification

may be warranted since SWEC does not utilize this program as its standard

practice.

2. It was not apparent to the team how the engineering mechanics department at

SWEC is reviewing the effectiveness of the project's handling of design

changes in the pipe stress and pipe support areas. The adequacy of the

review plans for this area remains an open item.

-3-

. .

III.' Electrical Discipline / Instrumentation & Control Discipline

. ,

In the electrical and I&C areas, the NRC Team generally found the depth of

review consistent with that of an IDI or IDVP. The Team also found the SWEC

, reviewers to be highly qualified technically and familiar with the technical

,

issues and concerns expressed by the NRC Team. The following comments are

.

S considered noteworthy:

V,

i

'

1. .The Team reviewed the draft SWEC electrical inputs to the Document Review

Plan (DRP) for Task 85-1 Control Room HVAC system.

a. The NRC Team found that SWEC inputs to the DRP did not specifically

identify the applicable FSAR Section, Design Critoria, Standards,

'

etc. Documents reviewed were not referenced by Document Number and

revision date as well as Document Title. How HL&P plans to ensure

the DRP's traceability remains an open item.

b. A number of items in the specific task plan were not reviewed at

this time. HL&P's review of the following areas remains open pending

confirmation that they have been included:

'

1) Motor operated valve feeder sizing and overload heater

selection will be covered in Task 85-2 because there were no

MOVs in the HVAC system studied.

2) Motor starting and running voltage as well as equipment

grounding will be reviewed in 85-3.

2. The Team also reviewed the controls sections to Task 85-1 and had the

following comments:

a. The Team observed that the system description and the set point

'

calculations had not yet been prepared and therefore the SWEC reviewer

correctly identified this portion of the review as indeterminate.

Review of these documents remains an open item.

.

, b. The Team found that the following interfaces identified in the

'

Control Room HVAC system design criteria and the scope document for

i ,

Task 85-1 were not included in the SWEC review.

, Review of these interfaces remains an open item.

1) The system design criteria indicates that the chilled water

supply is required to maintain the Control Room air handling

unit discharge air at 53 F. The Team noted that chilled water

was controlled by a three-way on-off valve in series with the

cooling coil. This would put full cooling water flow either

through the coil or completely bypass the coil. The

,

ventilation calculations used a maximum discharge temperature

[; of 53 F. The control circuit was not reviewed by SWEC.

' '

!

2) The system design criteria requires that the control of deluge

valve for the fire protection on the charcoal filters prevent

inadvertent actuation. This control system was not reviewed by

SWEC.

-

,

i

j'

-4-

< _

l

c. In certain instances, the Team found that the SWEC review did not

identify or question the effect of potential failures of non-safety-

related equipment on the safety-related equipment.

1) Nine large non-safety-related duct heaters are required by the

design criteria to be tripped on an accident condition. While

the reviewer did verify that an interlock was provided from the

engineered safety features actuation system to trip these

units, the reviewer failed to note that this interlock was used

in a non-safety-related de control circuit to trip non-safety-

related load center breakers. This type circuit must be

energized to trip the load. Because non-safety-related

equipment was utilized to trip these loads, load shedding could

not be assumed. The HVAC calculation for the Control Room

ventilation is based upon no heat input from these sources.

2) The Computer Room cooling unit is non-safety-related and is fed

from the normal chilled water system. No review had been

performed to review the potential flooding effects in the

Control Room area caused by failure of the Computer Room

cooling unit during a seismic event. Also the system design

criteria implies that the Computer Room cooling unit is

shutdown during plant upset condition. This would eventually

force the plant computer to be shutdown. This area had not

been reviewed by SWEC.

d. Approximately twelve different type instrumentation devices are used

on this system. The team found that the reviewer only looked at the

toxic gas analyzer. The radiation monitors, which were specifically

identified in the scope document and in the document review plan, had

not been reviewed by SWEC because the documentation was not available.

The Team also noted that, contrary to their expectations, SWEC did not

include one complete instrument loop in their review. The Team had

expected to see a sample of complete instrument loops reviewed from

the sensor through the transmitter, to the electronic processing

equipment, to the output signals, to the controlled devices and

, monitors. Review of the aforementioned areas remains an open item.

3. The Team also reviewed the scope document and document review plans for

Task 85-3 Part II medium voltage AC. The following items remain open

pending confirmation that they have been included in SWEC's review of

85-3:

a. System short circuit studies are limited to the medium voltage switchgear

rather than extended to the medium voltage containment electrical

penetrations.

b. The control of the loading of the diesel generator did not include a

review of the emergency power sequencer (interdiscipline interface).

.

-5-

7

. ,

c. The review of the control of the medium voltage switchgear was not

,

extended to the capability of the de bus to adequately supply dc

control power from the 125 V de batteries (system interface).

d. Protective relaying calculations were not reviewed for different

type loads on the medium voltage buses including motors, load -

centers, and backup protection for the electrical penetrations.

e. A review of the NSSS interface did not include the undervoltage and

underfrequency inputs into the reactor protection system and the

-

NSSS outputs to the medium voltage switchgear.

.

4

i

-6-