SNB REGq

00

REACTOR SAFETY AN D

LICENSING ACTIVITIES

Office of Nuclear Reactor

Regulation

December 9, 2004

1
ACRONYMS

* ANS:

* BWR:

* CFR:

* EPU:

* FERC:

* GSI:

* ISO:

* MSPI:

* NEI:

* NERC:

* PRA:

* PWR:

* RES:

* RS:

* SDP:

* SE:

American Nuclear Society

Boiling-water reactor

Code of Federal Regulations

Extended power uprate

Federal Energy Regulatory Commission

Generic Safety Issue

Independent system operator

Mitigating Systems Performance Index

Nuclear Energy Institute

North American Electric Reliability Council

Probabilistic risk assessment

Pressurized-water reactor

Office of Nuclear Regulatory Research

Review Standard

Significance determination process

Safety evaluation

2
AGENDA

* Overview - J. Dyer

e Emerging Technical Issues w B. Sheron

- Power Uprate-Related Technical

Issues

- Generic Safety Issue - 191

- Electric Grid Reliability

- Buried, Medium Energy Cables

* Fire Protection - J. Hannon

* Reactor Oversight Process - S. Richards

3
EMERGING

TECHNICAL ISSUES

Dr. Brian W. Sheron

4
ADVERSE FLOW EFFECTS

FROM POWER UPRATES

* Some plants experiencing adverse

flow effects during extended

power uprate (EPU) operation

* Higher steam and feedwater flow

causing vibration and acoustic

loading

5
ADVERSE FLOW EFFECTS

* Safety concern is failure of steam

dryer that can result in loose parts

in primary system

* Boiling-water reactors (BWRs) with

"square hood" steam dryer and high

steam velocity currently considered

most susceptible

* EPU flow-induced vibrations have

also caused failures of feedwater

probes and safety-related valves

6
INDUSTRY ACTIVITIES

Two units have reduced power to

pre-EPU levels and are replacing

the steam dryers

* BWR licensees are monitoring and

inspecting for signs of dryer

degradation

* BWR Owners' Group leading

industry activities to resolve

issues

7
STAFF ACTIVITIES

* Evaluating plant-specific response

to adverse flow effects

* Carefully reviewing current power

uprate requests for consideration

of flow effects

* Office of Nuclear Regulatory Research (RES) activities to

understand adverse flow effects

* Developing criteria for

determining the acceptability of

future power uprate requests

8
FUTURE PLANS

d Review licensee justifications for

- returning most susceptible units

to EPU operation

- Continued operation at EPU levels

for two other susceptible units

e Review two current requests for

EPU operation

* Monitor/review BWR Owners' Group

actions and determine need for

generic communication

9
GENERIC SAFETY ISSUE

(GSI) - 191

O Post accident debris accumulation

on pressurized-water reactor (PWR)

sump screens may lead to

inadequate long-term' core cooling.

O Bulletin 2003-01

e Generic Letter 2004-02

10
STATUS

* Nuclear Energy Institute,

NEI 04-07, "PWR Containment

Sump Evaluation Methodology"

* Staff responded to the Advisory Committee on Reactor Safeguards comments on NEI evaluation

methodology and staff safety evaluation (SE)

* SE on the evaluation methodology

11
STATUS

(Continued)

* Public meetings and NEI workshop

December 2004

* Chemical precipitation effects

testing November 2004

* Downstream effects to be

evaluated when performing overall

evaluation -methodology

12
CONCLUSIONS

e The SE and NEI Guidance

document provide a conservative

and acceptable evaluation

methodology

e The staff intends to proceed such

that this issue can be closed on

schedule - December 2007

13
GRID RELIABILITY

e August 14, 2003 Blackout

raised concerns regarding reliability of offsite power

* Risk insights pointed to th

following:

- Long duration Loss of Of

Power events are safety significant

- Risk increases due to on

equipment outages

- Grid is less reliable durir

Summer period

Event

the

e

fsIte

line

ig the

14
STAFF ACTUVITIES

* Staff raised awareness by issuing Regulatory Issue Summary 2004-05

O Staff issued Temporary Instruction

2515/156, "Offsite Power System

Operational Readiness".

* NRC entered into memoranda of

agreements with NERC and FERC

* RES Reports

15
NEXT STEPS

* The staff is considering a generic

communication to address:

-Agreements between the plant

and independent system

operator (ISO)

Ensure plant voltage needs

against grid voltage predictions

* Staff may reevaluate regulatory

requirements

16
BURIED CABLE FAILURES

* 22 reported buried cable failures

- Failed cables were not qualified

for moist environment

- Most failed cables were within

10 to 20 years of service life

e Increased number of failures are

expected to occur as plants age

* Failure of certain buried cables

could lead to loss of a train or

safety function

17
REGULATORY ACTIONS

* Staff sent a letter to industry on

February 5, 2004 and held a public

meeting on June 2, 2004

* Staff awaiting industry white paper

on issue

* Staff is evaluating options

18
FIRE PROTECTION

John Hannon

19
CLOSURE OF

LONG-STANDING ISSUES

* Risk-informed performance-lbased

rule, circuit analysis, and operator

manual actions rulemaking

* Management of emerging issues

* Use of state of the art tools

20
RISK-I NFORMVED

PERFORMANCED BASED

RU LEMAKI NG

o Rule & Enforcement Policy issued

June 2004

* Draft Regulatory Guide issued for

comment in September 2004

* Endorsement of industry guidance

on implementation

21
CIRCUIT ANALYSIS

e Issued Regulatory Issue Summary

2004-03 in March 2004

* Circuit analysis inspection

resumes January 2005

o Generic communication in early

2005 on compliance expectations

with Appendix R to 10 CFR Part 50

22
OPERATOR MANUAL

ACTIONS RULEMAKING

* Public meetings on acceptance

criteria (November 2003 and

June 2004)

* Proposed rule and draft regulatory

guide to Commission in

December 2004

23
EMERGING ISSUES

* Protocol for resolution of

emerging fire protection issues

exists between industry and NRC

-for low risk items.

24
REGULATORY TOOLS

e Revised fire protection

significance determination

process (May 2004)

o Fire Dynamics Tools

(November 2004)

e Fire probabilistic risk assessment

(PRA) Requantification Study and

Fire Modeling Verification &

Validation supported by RES

O American Nuclear Society (ANS)

Fire PRA Standard (early 2005) 25
REACTOR OVERSIGHT

PROCESS ISSUES

Stu Richards

26
FY 2003 I NDUSTRY

TRENDS RESULTS

* No statistically significant

adverse industry trends in safety

performance identified

e Three "Early Warning" prediction

limits were-crossed

27
FY 2004 INDUSTRY

TRENDS PRELIMINARY

RESU LTS

e Data through June 2004

-All Industry Trend Indicators

below "early warning" prediction

limits

o Final data available January

28
MITIGATING SYSTEMS

PERFORMANCE INDEX

(MSPI) ACTIVITIES

* One year pilot of MSPI completed in early 2004

o Significant issues resolved

* Target implementation date for

early 2006

29
MSPI ACTIVITIES

continued)

* Staff-industry PRA task force

created

* Implementation details under

development

* MSPI to be implemented at all

sites at the same time

30
SIGNIFICANCE

DETERMINATION PROCESS

(SDP) TIMELINESS

e Goal: 85 percent of findings

dispositioned in < 90 days

* Current SDP timeliness about

70 percent

e Fire protection and unique issues

have been particularly challenging

31
CONSIDERATIONS TO

IMPROVE SDP TIMELINESS

* Use modified SDP Phase 2 result

as preliminary risk estimate

o Develop qualitative criteria for

findings not amenable to SDP

o Adhere to strict time lines

* Use new information to revisit

previously evaluated findings

32
*STATUS OF

DESIGNIENGINEERING

PILOT PROGRAM

* Vermont Yankee pilot inspection

completed

-no risk significant issues

identified (eight green issues)

-suggest the need to assess

aspects of current inspection

program (power uprate/generic

issues)

33
STATUS OF

DESIGN/ENGINEERING PILOT

PROGRAM (Continued)

* VC Summer inspection complete

* Diablo Canyon and Kewaunee

scheduled for early 2005

34
CONCLUSIONS

35