ML20154N470
ML20154N470 | |
Person / Time | |
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Issue date: | 10/16/1998 |
From: | Seale R Advisory Committee on Reactor Safeguards |
To: | Callan L NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
References | |
ACRS-R-1783, FACA, NUDOCS 9810210300 | |
Download: ML20154N470 (13) | |
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>*A t;ti t_ 'o UNITED STATES g I
. 8 o NUCLEAR REGULATORY COMMISSION
$ , ,I ADVISORY COMMITTEE ON REACTOR SAFEGUARDS - ACRSR-1783 g .o WASHINGTON, D. C. 20555 )
NR October 16,1998 l
Mr. L.- Joseph Callan Executive Director for Operations 1
- ~ U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 {
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Dear Mr. Callan:
l SUBJEC.. PROPOSED PRIORITY RANKINGS OF GENERIC SAFETY ISSUES:
TENTH GROUP
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4 During the 455th and 456th meetings of the Advisory Committee on Reactor Safeguards, !
September 2-4 and September 30-October 2,1998, we reviewed the priority rankings proposed
. by the NRC staff for the Generic Safety issues (GSis) listed in Table A. During our review, we had the benefit of discussions with representatives of the NRC staff. We also had the benefit of the documents referenced.
Our comments on various GSis considered during these meetings are contained in the following attachments:
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Attachment 1 lists those GSis for which we agree with the priority rankings proposed by the NRC staff.
Attachment 2 identifies the GSis for which we agree with the priority rankings proposed
- by the staff, but have comments.
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- Attachment 3 identifies the GSI for which we disagree with the priority ranking proposed by the staff.
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. In addition to the comments on the proposed priority rankings, we offer the following comments and recommendations on the GSI process:
Overall GSI Process t
in recent years, the GSI process has not functioned properly. This may be attributed to e
frequent changes in management responsible for its implementation. The staff should improve its capability to perform cost / benefit analysis and to use the risk-informed
- approach in prioritizing and resolving GSis.
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Prioritintion in SECY-98-166, " Summary of Activities Related to Generic Safety issues," the staff proposes to discontinue use of the term "nearly resolved" and to revise NUREG-0933 to reflect this change in terminology. This proposed action will resolve our concern regarding the use of the term "nearly resolved," which has been a misleading category in the GSI prioritization process. For example, GSI-190, " Fatigue Evaluation of Metal Components for 60-Year Plant Life," which was classified as "Nearly Resolved"in 1996,
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is yet to be resolved. Similarly, GSI-191, " Assessment of Debris Accumulation on PWR l Sump Performance," was categorized as "Nearly Resolved"in 1996. In the document ;
provided to us, the staff states that research will be initiated in FY 1998 to resolve this ;
issue, which may take several years to complete. 1 Several of the 20 GS!s provided for our review were categorized as "Nearly Resolved."
In SECY-98-166, however, these issues were arbitrarily recategorized as HIGH. The basis for these rankings should be documented.
Another category used in the prioritization process is " Resolved." We beneve that there have been cases where this term is used too loosely. For example, the existence of a plan to resolve a particular GSI does not necessarily mean that the issue has been techn!cally resolved. The staff should ensure that an adaquate technical basis exists prior to declaring that a GSI has been resolved.
As part of a reevaluation of the GSI process, thought should be given to the appropriateness of using the classifications " Regulatory impact Issue,"" Licensing Issue," and "Environmentalissue"in the prioritization process. Irrespective of additionai terminology applied to an issue, we believe that all issues should be prioritized as HIGH, MEDIUM, LOW, or DROP to provide consistency throughout the Agency. The emphasis by the Commission on reducing unnecessary regulatory burden to the industry supports the need for prioritizing the issues placed under the above three categories. Also, resolution of these issues should be clearly documented.
In our March 16,1998 report, we noted that the planning by the Office of Nuclear Regulatory Research calls for the prioritization of two to three GSts per year. In our April 12,1988 report to the Commission, we stated that the average time required to assign a priority to a GSI is about six months, which we do not consider Jnreasonable.
It is disturbing to see that the range of times involved in prioritizing GSis varies widely.
For example, GSI-163, " Multiple Steam Generator Tube Leakage," identified iri 1992, was not prioritized until 1997, and GSI-169, "BWR MSIV Common Mode Failure Due to Loss of Accumulator Pressure," identified in 1993, was not prioritized until 1998. The staff should take efforts to ensure that GSis are prioritized expeditiously.
The methodology used in the prioritization process is technically sound, but the staff should ensure the quality and appropriateness of the assumptions used in the analysis supporting the priority ranking of a particular GSI. For example, we recently reviewed the proposed resolution of GI-171, "ESF Failure From LOOP Subsequent to a LOCA,"
which was assigned HIGH priority ranking in 1995. Based on reassessment of the
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I 3-l assumptions and the frequency numbers used in calculating the core damage frequency (CDF), the CDF decreased by three orders of magnitude . This raises concern about the validity of the assumptions and analyses used in prioritizing other GSIs.
i Resolution 4
Fifteen of the GSis identified since the 1979 amendment to the Energy Reorganization Act of 1974 have still not been resolved We strongly urge continued effort to resolve
- these issues, i The staff has assumed that the safety concerns associated with several GSis would be -
addressed by the licensees in the individual plant examination / individual plant examination for external events (IPE/IPEEE) programs. We recommend that after
[ completing the review of the IPE/IPEEE submittals, the staff provide a report documenting whether the concems of these GSis were, in fact, addressed adequately so that they can be considered resolved. Those issues that were not adequately
{ addressed should be prioritized and resolved.
4 Coordination The senior management of the Office of Nuclear Reactor Regulation and the Office of Nuclear Regulatory Research should ensure adequate coordination between their
- offices to resolve technical differences associated with GSIs in a timely manner to
- facilitate expeditious prioritization and resolution of GSis, i
j Sincerely,
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) R. L. Seale i Chairman Attachments: As stated
- References-
- 1. Memorandum dated July 6,1998, from L. Joseph Callan, Executive Director for Operations, NRC, for The Commissioners,
Subject:
SECY-98-166, " Summary of
.i Activities Related to Generic Safety issues."
3 2. Report dated March 16,1998, to L. Joseph Callan, Executive Director for Operations, l' NRC, from R. L. Seale, Chairman, ACRS,
Subject:
SECY-98-001, Mechanism for Addressing Generic Safety issues.
- 3. Report dated April 12,1988, to the Honorable Lando W. Zech, Jr., Chairman, NRC, from W. Kerr, Chairman, ACRS,
Subject:
Effectiveness of Programs Relating to Generic and Unresolved Safety Issues - ACRS Comments.
. 4. Letters dated February 24,1998, to The Honorable Albert Gore, Jr., President of the i United States Senate, and The Honorable Newt Gingrich, Speaker of the United States i
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4 Ho'. se of Representatives, from R. L. Seale, Chairman, ACRS, transmitting " Nuclear Safety Research, A Report to the U.S. House of Representatives and the U.S. Senate."
- 5. Memorandum dated September 16,1993, to James M. Taylor, Executive Director for Operations, NRC, from J. Ernest Wilkins, Jr., Chairman, ACRS,
Subject:
Proposed Priority Rankings of Generic Issues: Eighth Group.
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, . l TABLE A I l
TENTH GROUP OF GENERIC SAFETY ISSUES !
REVIEWED BY THE ACRS DURING THE 455TH MEETING. SEPTEMBER 2-4.1998 i
l Generic Safety issue Number Title Priority Ranking Proposed by the NRC Staff 1
! 163 Multiple Steem Generator Tube HIGH Leakage l 169 BWR MSIV Common-Mode DROP Failure Due to Loss of (Based on the impact /value ratio and the :
Accumulator Pressure total risk reduction potential, this issue is I in the drop category.)
170 Fuel Damage Criteria for High HIGH I Bumup Fuel (Current data cannot be correlated to l design criteria and conclusive data will not be available for several years. ,
Research is continuing on assessing the l adequacy of fuel damage criteria at high l burnups.)
L. 172 Multiple System Responses HIGH Program (Dat i are being collected to evaluate the manner in which the MSRP concerns were addressed by licensees in their IPE/IPEEE submittals. Staff assessment of licensee submittals will determine whether the concems have been adequately addressed.)
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Generic Safety issue Number - Title Priority Ranking Proposed by the NRC Staff 173 A Spent Fuel Storage Pool for HIGH Operating Facilities (The staff is in the process of revising its guidance documents for spent fuel storage design (i.e., portions of SRP 9.1.3 and Regulatory Guide 1.13).
Currently, the staffis working with industry (an ANS Subcommittee) to -
revise ANSI /ANS-57.2, the standard that contains guidance for spent fuel storage pool design. The staff plans to incorporate the improvements from this standard into.a reyised SRP and Regulatory Guide. The expected i
completion date for issuance of the revised guidance documents is August 2000.)
173 8 Spent Fuel Storage Pool for HIGH (Resolved)
Permanently Shutdown Facilities (No generic action was required.)
174 A Fastener Gaging Practices RESOLVED (This issue was resolved and no new requirements were established.)
174 B' Johnson Gage Company Concern RESOLVED (This issue was resolved and no new requirements were established.)
175 Nuclear Power Plant Shift Staffing RESOLVED (This issue was resolved and no new requirements were established.)
176 Loss of Fill-Oilin Rosemount RESOLVED Transmitters (This issue was resolved and no new requirements were established.)
177 Vehicle Intrusion at TMI RESOLVED (This issue was resolved and no new requirements were established.)
178 Effect of Hurricane Andrew on RESOLVED Turkey Point
Generic Safety issue Number Title Priority Ranking Proposed by the NRC l
Staff 179 Core Performance LICENSING ISSUE (Resolved) i (This issue addresses the staffs efforts in clarifying existing requirements and guidance and, therefore, is classified as a Licensing issue. This issue was resolved with the issuance of the revised staff guidance.)
180 Notice of Enforcement Discretion RESOLVED (This issue was resolved with the issuance of the revised staff guidance.)
181 Fire Protection LICENSING ISSUE (This issue addresses the staffs efforts in improving its capability to make independent assessments of safety and is classified as a Licensing issue. NRR is in the process of completing pilot Fire Protection Functional inspections.)
182 General Electric Extended Power REGULATORY IMPACT ISSUE Uprate (This issue does not affect safety but could have an economic impact on the -
operation of plants with GE reactors.
Therefore, it was classified as a Regulatory Impect issue.)
183 Cycle-Specific Parameter Limits in RESOLVED Technical Specifications 184 Endangered Species ENVIRONMENTAL ISSUE (This issue addresses impact on the environment of nuclear plants and, therefore, is classified as an Environmental lasue.)
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Generic Safety issue Number Title Priority Ranking Proposed by the NRC Staff 190 Fatigue Evaluation of Metal HIGH Components for 60-Year Plant (The staff is studying the risk of failure Life from fatigue of selected components. A
. report," Fatigue Analysis of Components for 60-Year P! ant Life"is under way, making use of updated fatigue design curves for stainless steel developed by Argonne National Laboratory in March 1998. This issue is expected to be resolved by March 1999.)
101 Assessment of Debris HIGH Accumulation on PWR Sump (Research is being planned on coatings Performance and debris transport to determine the potential severity of PWR sump blockage effects. This work will be initiated in FY 1998 and may take several years to complete.)
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' ATTACHMENT 1 ,
c LIST OF GENERIC SAFETY ISSUES FOR WHICH THE ACRS AGREES WITH THE PRIORITY RANKINGS PROPOSED BY THE NRC STAFF L
faRDeric Safety lasue No. tan
- .163 Multiple Steam Generator Tube Leakage i 169 BWR MSIV Common-Mode Failure Due to Loss of Accumulator Pressure 172- Multiple System Responses Program 3
Issue 3 Failure Modes of Digital Computer Control Systems Issue 4 Specific Scenarios Not Considered in USI A-47 l.
Issue 5 Effects of Degradation of HVAC Equipment on Control and Protection Systems issue 6 Failure Modes Resulting From Degraded Electric Power Sources
) Issue 7 Failure Modes Resulting From Degraded Compressed Air Systems
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issue 8 Potential Effects of Untimely Component Operation i
Issue 9 Propagation of Environments Associated With DBAs
- lssue 11 Synergistic Effects of Harsh Environmental Conditions Issue 12 Environmental Qualification of Seals, Gaskets, Packing, and Lubricating
! Fluids Associated With Mechanical Equipment 173 A Spent Fuel Storage Pool for Operating Facilities 173B Spent Fuel Storage Pool for Permanently Shutdown Facilities
) 174 A Fastener Gaging Practices - SONG's Employees' Concern l 174 B Fastener Gaging Practices - Johnson Gage Company Concem 176 Loss of Fill-Oil in Rosemount Transmitters f.
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, 177 Vehicle intrusion at TMl '
178 Effect of Hurricane Andrew on Turkey Point l
179 Core Performance .
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- 180 Notice of Enforcement Discretion i -
- 181 Fire Protection - !
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] 182 General Electric Extended Power Uprate i 104 Endangered Species e
9 190- . Fatigue Evaluation of Metal Components for 60-Year Plant Life 191 Assessment of Debris Accumulation on PWR Sump Performance ,
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ATTACHMENT 2 LIST OF GENERIC SAFETY ISSUES FOR WHICH THE ACRS AGREES WITH THE PRIORITY RANKINGS PROPOSED BY THE NRC STAFF.
BUT WITH COMMENTS Generic Safety lasue No. - 170 Idla : Fuel Damage Criteria for High Bumup Fuel Priority Rankina HIGH Prooosed by the NRC Staff :
ACRS Comments :
The research program that will technically resolve this issue is directed toward providing confirmatory evidence in support of regulatory decisions that have been made. The research program should ensure that adequate technical foundations and analytical tools are available to
. the NRC line organizations to meet regulatory needs. The research program needs to resolve criticisms leveled by NRC contractors conceming the adequacy of the treatment of delayed neutron fraction in neutron transport codes. The research program needs to document peer review arguments that criticality events will not occur if fuel is dispersed in fuel channels by credible reactivity insertion events. There must be confidence that local fuel damage does not propagate into large regions. The research program needs to ensure that Baker-Just clad '
oxidation kinetics used in Appendix K analyses are bounding for high-bumup fuel whose clad is susceptible to thermal stress fracture and breakaway oxidation. The research program also needs to develop plans to examine high bumup fuel behavior during anticipated transients without scram (ATWS) events and ATWS recovery processes.
Generic Safety Issue No: 172 Idle; Multiple System Responses Program Priority Rankina HIGH i Proposed by the I NRC Staff ACRS Comments: l J
Of the 21 Multiple System Responses Program (MSRP) issues,11 issues were to be addressed in the IPE/IPEEE programs. After reviewing the IPE/IPEEE submittals by the i licensees, the staff plans to prepare a summary report on how these 11 issues were addressed !
in the IPE/IPEEE programs. In the summary report, the staff should document clearly whether j these issues have been adequately addressed by the licensees in the IPE/IPEEE programs. !
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Those issues found to be not addressed properly should be reprioritized and resolved expeditiously. Subsequent to reviewing the staff's summary report, we will decide on the adequacy of the treatment of these 11 issues in the IPEllPEEE programs. I Issue 10: Evaluation of Heat, Smoke, and Water Propagation Effects Resulting From Fires I
This issue addresses the question about how effluents and heat generated during a fire might '
disperse from the site of the fire and affect equipment in other locations. The staff plans to address the effects of environmental stressors on digital electronic equipment, including the effects of smoke as a separate issue. We plan to review the proposed resolution of this issue.
Generic Safety issue No: 175 Iltli Nuclear Power Plant Shift Staffing l
Priority Rankina RESOLVED Pro o_ osed by the '
NRC Staff:
ACRS Comments: .
I The staff should continue to monitor operating events and incidents to provide feedback regarding operational challenges and reassess the adequacy of staffing and task allocation, as appropriate.
Generic Safety Issue No : 183 Iltle : Cycle-Specific Parameter Limits in Technical Specifications l Priority Rankino RESOLVED Procosed bv the NRC Staff:
ACRS Comments :
Performance by an individuallicensee should not be used as the basis for closure of generic safety issues that are intended to reduce the regulatory burden on the nuclear industry. We recommend that the regulatory requirements identified by the Regulatory Review Group as being candidates for elimination be reconsidered under the generic safety issue process.
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t ATTACHMENT 3 GENERIC SAFETY ISSUE FOR WHICH THE ACRS DISAGREES WITH THE PRIORITY RANKING PROPOSED BY THE NRC STAFF Generic Safety lasue No.: 172 TdhL ' Multiple System Responses Program
/ssue 16: Seismically induced Fires Priority Rankino DROP Prooosed by the -
NRC Staff
- ACRS Comments
Seismic events can cause fires and, at the same time, damage the capacity to suppress fires because fire suppression systems are not adequately qualified for seismic events. The staff acknowledges the existence of the issue and expects that it will be adequately addressed in the
- IPEEE process. At the same time, the staff has identified some 12 major issues with the industry-developed tool, Fire induced Vulnerability Evaluation (FIVE) Methodology, for analysis of fire and some 42 deficiencies of probabilistic risk assessment techniques for the analysis of fire. It would seem unlikely that even the most diligent licensee efforts to address the issue in 3.- its IPEEE program would yield persuasive results. It seems that the issue must remain open
- i. until we have a chance to review the findings of the IPEEE effort.
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