ML16138A455

Summary of 800821 Meeting W/B&W Reactor Owners Group Re Abnormal Transient Operating Guidelines Program

ML16138A455
Person / Time
Site:	Davis Besse, Oconee, Arkansas Nuclear, Crystal River, Rancho Seco, Crane
Issue date:	09/30/1980
From:	Vissing G Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
Shared Package
ML16138A456	List: ML16138A455
References
TAC-44335, NUDOCS 8010230589
Download: ML16138A455 (29)

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ISSION WASHINGTON, D. C. 20555 SEPTEMBER 3 0 1980 Dockets Nos. 50-269, 270, 87 289, 302,

312, 313, an 346 FACILITIES:

Oconee-1, 2, and 3, Three Mile Island 1, Rancho Seco, Arkansas Nuclear One, Unit 1, Davis-Besse 1, and Crystal River-3 LICENSEES:

Babcock and Wilcox Reactor Owner Group -

Duke Power Company, Metropolitan Edison Co.,

Sacramento Municipal Utility -.

District, Arkansas Power and Light Co.,

Toledo Edison Co.,

and Florida Power Corporation

SUMMARY

OF MEETING WITH THE B&W OWNERS GROUP CONCERNING THE ABNORMAL TRANSIENT OPERATING GUIDELINES (ATOG)

PROGRAM Introduction The purpose of the meeting was to discuss the ATOG Program for B&W reactors.

The attendees are identified in Enclosure 1.

An ATOG Proqram serves as a basis for procedure development which will provide for operator actions developed from reactor symptoms rather than from particular events. The output from the program are two reports. One report is an operator training manual. The other report contains guide lines which would serve as operating procedures.

This program was presented by letter dated November 7, 1979. It was further discussed at a meeting with the B&W Owners Group on February 22, 1980.i As a result of this meeting the first submittal consisting of Event Trees from ANO-1 Safety Sequence Diagrams was provided by letter fromB&W dated April 16, 1980.

The second scheduled submittal consisting of draft Guidelines (Part I and II) for ANO-1 was provided at this meeting.

Added to the agenda of this meeting was the issue concerning the Lessons Learned Item 2.1.3.6, "Instrumentation for Detection of Inadequate Core Cooling".

Conclusions The staff considers the approach of the ATOG Program to be an acceptable approach and would look for a formal submittal.

Since it appears that the ATOG Program, when implemented, would impact upon the 500 subcooling margin and the criteria for tripping the reactor coolant pumps, the staff requested a formal submittal of the Licensees' intentions.

o 2-3,a

-2 Two copies of the draft reports were retained by the staff. Five additional copies will be provided to the staff. The staff will provide comments on the reports.

With regards to the issue concerning "Instrumentation for Detection of Inadequate Core Cooling" the Owners Group objected to the requirement particularly since they have not had any indication that the staff has reviewed all the documentation on the dockets relating to this issue. The staff maintained the position that an unambiguous vessel level instrumentation is a requirements.

Discussion The B&W Owners Group provided a prepared discussion with view graphs (Enclosure 2), which are self explanatory. The staff presented its position for an unabmiguous vessel level instrumentation. The Owners Group cannot see the usefullness of such an instrument since operating procedures would not use such instrumentation for guidence. The staff believes such instrumentation is necessary to detect a steam bubble condition in the vessel.

The staff will reconsider this position after review of documentation by the licensees in response to Lessions Learned 2.1.3.6.

Guy Vissing, Project Manager Operating Reactors Branc #4 Division of Licensing

Enclosure:

1. Attendance List

2. Meeting agenda cc w/enclosure See next page

MEETING

SUMMARY

DISTRIBUTION Licensee: Mr. W. Parker, Mr. R. C. Arnold, Mr. J. J. Mattimoe, Mr. W. Cavanaugh, Mr. R. P. Crouse, and Mr. J. A. Hancock

• Copies also sent to those people on service (cc) list for subject plant(s).

Docket File -3 NRC PDR L PDR TERA-8 NSIC

-. ORB Rdq NRR Rdg HDenton ECase DEisenhut RPurple RTedesco TNovak GLainas RReid TIppolito SVarga DCrutchfield RAClark ORB Project Manager Licensing Assistant OELD AEOD - JHeltemes IE-3 SShowe (PWR)

Meeting Summary File-ORB RFraley, ACRS (16)

Program Support Branch G ech 6oe NRC. Participants See enclosure 1 ATTENDANCE LIST OF MEETING WITH B&W OWNERS GROUP CONCERNING ATOG August 21, 1980 NAME ORGANIZATION Guy S. Vissing..

NRC/NRR/ORB#4 Mark L. Padovan NRC/NRR/ORB#4 Joe Kelly Babcock & Wilcox Denny Napior Babcock & Wilcox Courtney Smyth GPU Dan Williams AP&L Rene F. Audette NRC/NRR/RSB John Bohart B&W R. L. Gill Duke Power Mort Fairtile NRC/NRR/ORB#4 Daniel Garner

.NRC/NRR/ORB#4 Dominic C. Dilanni-ORB#4/NRR Brian W. Sheron RSB Thomas M. Novak DOL Edward B. Blackwood NRC/IE Don Beckham PTRB/DHFS G. B. Peeler NUS Hal Ornstein NRC/AEOD Hal Perry Flordia Power Corp.

D. L. Ziemann NRC/DHF/PTRB Edward Throm NRC/DSI/RSB R. W. Reid NRC/DL/ORB#4 R. C. Twilley B&W L. S. Rubenstein NRC/CCS L. E. Phillips NRC/SDI/CPB T. L. Huang NRC/DSI/CPB B&W OWNERS GROUP NRC MEETING AUGUST 21, 1980 AGENDA ABNORMAL TRANSIENT OPERATING GUIDELINES (ATOG)

1. Background and Objectives D.A. Napior

2. Program Status D.A. Napior

3. Guideline Overview J.J. Kelly

a. Engineering Basis and Principles of Operation

b. Operating Guidelines

4. Major Operational Considerations J.J. Kelly 5.. Examples of Selected Transients J.J. Kelly

ATOG Objective Simplify operator problem of identifying and treating abnormal transients

Methodology Event trees Analysis Design basis/expected plant response Simulation Operator feedback

g1 Transients Selected for Guideline Prep rtion '

Increase in heat removal by secondary system

• Small steam leaks

• Excessive feedwater flow

0. Decrease in heat removal by secondary system

• Loss of feedwater

• Loss of station power

• , Decrease in reactor coolant inventory

• Steam generator tube rupture

• Inadequate core cooling

• Loss of coolant

Event Trees.

Purpose Systematically determine various plant conditions which can evolve following a postulated initiating event Assumptions Initial conditions Equipment failures Operator action

Analysis

Purpose:

Realistically portray expected plant response Analyze:. Design success path All single failure paths Discuss subsequent failures:

Verify LOCA paths covered in small break 0

guidelines

Design Basis/Expected Plant Response

• Communication between designer and operator

• Supports operator action portion of guidelines 0 Written for operator understanding

Training Simulator

• Test various methods of approach to guidelines

• Verify final product

• Train operator 0

Operator Feedback Detailed review of event trees Input to guideline format

• Plant walk through Training

Closin3 th loop Designers Operators Analts Trainers Guideline o procedure raters

Utility rnput data Transtent Analysis WaDefines time to key events, mConfirms parameter trends Organizes plant specilic provides specihe symptoms o adtadntisfetyns on Event Tree selected event tree twanches.

an ntSystematically determine various plant sse/prresponse t

v sysemope rsposecondittens which can evolve following a durig evnt.postulated initiating event.

Draft opidelines Draft Guidelines As Utiit Im reiateaos processurns Cause Wheels (s ad's ttacaonsien.t sos e

dncfoind To provide input information fot

4. Foleowuptions tasn determining corrective actions woFlo patin rdnseti or the operating guidelines.

operator can unders Walk through at utility with operations personnel.

Training Simulator Test guidelines to as51surre accuracy of resultant plant response Final transient operating gutdems Abn~orgImal trainsient e

e aUtility writes procedures opferathIg guidelmnesL program Operator traima"

Part 1. Organization SECTION I. Immediate actions SECTION II. Vital system status verification SECTION Ill.

A. Treatment of lack of adequate subcooling margin B. Treatment of lack of primary to secondary heat transfer C. Treatment of too much primary to secondary heat transfer D. Follow up actions for OTSG Tube rupture COOLDOWN PROCEDURES

• Large LOCA

• Normal

• Saturated RCS

• HPI cooling

• Solid water "cooldown

1IIA 1.0-8.0 ELI A 1.0 7.0 Section III A Close URV Block Trip RCPs Valve (CV-100)

Follovup Actions for Treatment of Lack of Adequate Subcooling Nargim 2.0 1.0 Trip all RCPs.

Raise OTSG 8.0 2.0 If possible, raise OTSG levels to 90-95% on operate range while proparly Levels to 95%

Adequate YeG Subaooling throttling feedwater.

Le~el OTSGMargin 3.0 If ESAS actuates, balance HPI flow at approxiastely 250 gps per injec 3.0 No tion nozzle.

ESAS Yes Balance KPI actuated at approx. 250 4.0 Isolate all letdown.

gpm per nozzel Go to.

5.0 Compare Thot RTD and core exit thermocouple temperatures frequently fnor No 4.0 indications of:

Isolate 5.1 Natural Circulation - RTD and T/C readings track together letdown 5.2 Inadequate Care Cooling - RTD and T/C readings show superheated 5.0 conditions Coumpare Thot 5.3 If Inadequate Core Cooling is indicated, follow Inadequate Compa cre That RTD & coreeits Core Cooling Guidelines, otherwise continue.

T/C readings 6.0 Close Pressurizer Spray Block valve (CV-1009).

7.0 Close ERV block valve (CV-1000).

ICC Yes Go to ICC 8.0 If adequate subcooling margin has been established, go to step 8.1.

Indicated Guidelines If adequate subcooling margin has not been eastablisbed, go to step 8.7.

No 6.0 Close Pr.

Spray block Valve (CV-1009)

Part II. Organization VOLUME 1: Fundamentals of reactor control for abnormal transients A. Heat transfer B. Use of P-T diagram C. Abnormal transient diagnosis and mitigation D. Backup cooling methods E. Best methods of equipment operation F. Stability determination VOLUME 2: Appendices - Selected transients A. Excessive feedwater B. Loss of feedwater C. Steam generator tube rupture D. Loss of off-site power E. Small steam line break F. LOCA

Major Operational Changes Due To ATOG

• HPI Subcooling Rule

• HPI Termination And Throttling Guidelines

• RC Pump Trip Rules

• RC Pump Restart Criteria

• EFW Throttling Guidelines

• Steam Generator Level Guidelines

HPI Subcooling Rule Two HPI Pumps Should Be Run At Full System Capacity When:

• The ESAS Is Actuated And The HPI Is Automatically Started

• The Reactor Coolant Subcooled Margin Is Lost And The HPI Is Manually Started

HPI Termination And Throtting Guidelines (Figure 30)

• Throttle anytime RCS is subcooled, stop when PZR level is available

• Stop when LPI is cooling the core (2630 gpm LPI flow for 20 minutes)

• Prevent pump run out (550 gpm)

• Prevent pump burnup (< 100 gpm)

• Prevent reactor vessel thermal shock

RC Pump Trip Rule (Page 105)

The RC Pumps Shall Be Tripped Immediately Whenever The Subcooling Margin Is Lost

RC Pump Restart Criteria (Table 6)

• Restart When Subcooling Margin Regained

• Restart Under Special LOCA Conditions In Order To Force A Plant Cooldown

• Restart under extream ICC conditions

EFW Throttlirng GuidelineS (Page 127)

• Throttle as necessary to:

(1) Limit steam generator pressure reduction to

< 100 psig (2) Maintain a continuous feed flow (When below level setpoint)

(3) Maintain a continuous level increase (When below setpoint)

• Some restrictions on EFW throttling 0

1. One OTSG

2. Late actuation

3. Natural circulation stops before level is reached

Steam Generator Level Guidelines (Page 126)

• Anytime Subcooling Margin Is Lost The Level Should Be Raised To 95%

• Raise Level Using EFW Throttling Guidelines

• If Subcooling Margin Is Regained Adjust Level To Satisfy Existing RCP Status

1. No RCP's Running 50%

2. Any RCP's Running - Startup Level

2600 2400 POST TRIP bo 2200 WINDOW r ----

4.5 3 2

2000 STEAM TEMP.

SUBCOOLED SUPERHEAT 1800 R

REGION REGION 1600 E5 2

1400 C*

4 1200

3.

cc o

STEAM PRESSURE END POINT-POST TRIP WITH FORCED ca 1000 LIMIT CIRCULATION (THOT & TCOLO) 4 1

AND FOR NATURAL CIRCULATION (TCOLD) c 800 -

2 3

~NORMAL OPERATING POINT-POWER 600 -

OPERATION (THOT)

SUBCOOLED f

END POINT-POST TRIP WITH NATURAL 400 MARGIN LINE CIRCULATION (THOT) 400 450 500 550 600 650 100 Reactor Coolant And Steam Outlet Temperature-F

2600 POST TRIP Yi INDO o

2200

-I[

43, 2

21 en7 I

2t I

CU 2000 STEAM TEMP IN AFFECTED SG SUBCOOLED 1800 REGION

• -]SUPERHEAT 1600 REGION 3

L 1400 120 4

STEAM PRESSURE LIMIT END PotMT-POST TRIP W ITH C

1000 LI-IT FORCED CIRCULATION (THOT COLD 5

AND FOR NATURAL 0

2CIRCUI.ATION(TCOLD) asU NORMAL OPERATING POINT 600

-IO POWER OPERATION (THOT) 4

-f END POINT-POST TRIP \\'ITH 400

-SUBCDOLEDI 4

E -I

[7 NATURAL CIRCULATION (THOT)

U_

MAR G IN LINE L

1 l.I l

l

~ J il 400 450 500 550 600 650 700 Reactor Coolant and Steam Outlet Temperature, F

2400 POST TRIP WINDOW 2200

• 1 2000 SUBCOOLED 2

" EION SUPERHEAT 1800 REGION 1

1600

83.

1400 4',#

1200 STEAM PRESSURE LIMIT ENO POINT-POST TRIP WITH FORCED 1000

-CIRCULATION (THOT & 'COLO) AND FOR NATURAL CIRCULATION (TCOLo) 8 00 NORMAL OPERATING POINT-POWER go OPERATION (THOT)

SUBCOOLED MARGIN (F""1 END POINT-POST TRIP WITH NATURAL 400LINE CIRCULATION (THOT)

II I

I 400 450 500 550 600 650 100 Reactor Coolant And Steam Outlet Temperature-F

Extent Of ATOG Coverage (Goals)

• Replaces existing procedures for the five transients studied

• Replaces existing small break guidelines (except ICC portion)

• Replaces any existing interim overfill guidelines

• Replaces any existing interim SGTR guidelines

• We think it replaces any existing procedure that starts with reactor trip

• Provides guidelines for cooling down under various adverse conditions (cooldown procedures)

• CRT option provides reactor trip avoidance potential