ML20244D880
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ENCLOSURE BAT 19 m C. J. Heltemes, Jr., Director MEMORANDUM FOR: Office for Analysis and Evaluation of Operational Data Harold R. Denton, Director FROM: Office of Nuclear Reactor Regulation
SUBJECT:
DEFICIENT OrWTOR ACTIONS FOLLOWING DUAL FUNCTION VALVE FAILURES Your memorandum dated February 4,1586, suggests that NRR consider requestin function all licensees to examine their plant, piping configurations for dual valves and to amend their plant Technical Specifications as necessary to .
ensure that valves with two functions are addressed in each place Technical Specifications.
a LPCI suppression pool suction valve was placed in the deactivated-open )
position to maintain the LPCI operability after failing to open during a surveillance valve but was test.apparently not fully recognized by the plant operating staff.
We agree that more complete Technical Specifications may have prevented occurrence. ,
The Technical Specification Coordination Branch (TSCB) has included the need for Technical Specification fonnat changes to address such dual function situations reactors.
in the Technical Specification improvenunt progr TSCB, through coordination with the Facility Operations by this program.
4 ranches, has been and will continue to ensure that With respect to your recorynendation to issue an informati problems.
Harold R. Denton, Director f
Office of Nuclear Reactor Regulation Distribution W. Regan Central File '
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l FROM: Themis Speis
SUBJECT:
REVIEW 0F THE SEABROOK EPZ SUBMITTAL I have reviewed your proposed memo to H. Denton on the Seabrook review 1
l and provided comments in the form of markups to V. Noonan on August 8.
l It is important to decide what direction NRC is going to take on this issue before a detailed technical review can start. A decision chart set up in the torm of three questions is attached for your consideration, I would recommend that you assemble a small group to assess the potential approaches to the review. Four individuals, one from each, PWRL, DSRO, IE and OGC, could do the job in about two weeks. Our representative is Len Soffer, please feel free to contact him directly.
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l ORIGINAL SICitED BY l
l Themis Speis cc: H. Denton
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~~~Potantial Approaches to the Review of the Seabrook EPZ Submittal
- 1. Assuming that all technical information received from Seabrook is correct, can NRC reduce the Seabrook EPz or evacuation zone below the 10 mile limit uncer current regulations and established regulatory practice?
If answer is No, go to Q-2.
If answer is Yes:
What information is important for the decision?
What additional information is needed from PSNH? ,'
i 2. Can NRC use a risk based criteria to justify a reduction in EPZ or I evacuation zone for Seabrook without "rulemaking" or granting an exemption?
If answer is No - Seabrook should either join the ongoing rulemaking or go to y-3.
If answer is Yes:
What information is important for the decision?
What additional information is needed for PSNH?
- 3. What basis could NRL have for granting an exemption from existing emergency planning requirements for Seabrook?
a.) Is the Seabrook plant significantly different from other PWRs with large dry containments with respect to Emergency Planning requirements?
If answer is Ho, go to Q-3b.
If answer is Yes:
What information is important for the decision?
What additional information is needed from PSNH7 b.) Is there an "immediate need" for Seabrook, that would justify exempting it from current EPZ requirements while the rule change is underway?
If answer is No - give up!
If answer is Yes:
1 What information is important for the decision? l What additional information is needed from PSNH7 i I
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UNITED STATES f ,, g NUCLEAR REGULATORY COMMISSION g g WASHINGTON, D. C. 2o555
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MG 121986 ;
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MEMORANDUM FOR: Harold R. Denton, Director Office of Nuclear Reactor Regulation FROM: Thomas M. Novak, Acting Director Division of PWR Licensing-A
SUBJECT:
REVIEW OF EPZ SENSITIVITY STUDY FOR SEABROOK )
1 l
On July 21, 1986, Public Service of New Hampshire (PSNH) submitted a sensitivity study on the emergency planning zone (EPZ). The study provides a comparison of f I
dose versus distance curves for the Seabrook plant and site with similar generic curves from NUREG-0396 which were used in developing the EPZ regulation in 10 CFR 50.47. The study conc'.udes that a 1-mile evacuation radius at Seabrook
\ provides for a similar by NUREG-0396 for aor greater 10-mile degree ofradius evacuation public protection around thanconsiderert the plants was shown by WASH-1400.
1 The study is largely based on the Seabrook Probabilistic Safety Assessment that PSNH submitted about 3 years ago. The source terms used in the Emergency Planning Sensitivity study were drawn from the source terms used in the WASH-1400 calculations, with some modifications under specific scenarios.
Also, some of the probabilistic models have been changed from the Safety ,
Assessment. Thus, the report is intended to examine differences made by the '
Seabrook design and site, plus the improvements in accident sequence modeling capabilities, without credit for source term reductions that may result from recent studies. The EPZ study attributes reductions in the offsite dose pre-dictions to the higher strength of the Seabrook containment, a more refined failure modes analysis for the containment, and a more realistic treatment of the initiation and progression of interfacing systems LOCA sequences. Along with the Emergency Planning Sensitivity Study, PSNH has also submitted a report titled "Seabrook Station Risk Management and Emergency Planning Study,"
which provides results of Seabrook specific calculations with new source terms based upon the recent IDCOR work.
The conclusions of the EPZ Sensitivity Study are based upon comparison of the results of the study to three acceptance criteria that were drawn from NRC documents. One of the criteria is a comparison of the individual risk of early fatality in the population within 1-mile of the plant, assuming no W ) &
. 4 Harold R. Denton O immediate protective action, to the NRC proposed safety goal. A second criterion is the comparison of early fatalities at the Seabrook site, assuming a 1-mile evacuation, to the early fatalities results of WASH-1400, which assumed a 25 mile evacuation. The third criterion is the comparison of the risks of exposure to 1, 5, 50, and 200 rem whole body doses at various distances from the Seabrook site to the corresponding NUREG-0396 results at 10 miles, assuming no immediate protective actions. It should be noted that a presentation on this general subject was made to NRC a few months ago by the AIF Subcommittee on Emergency Planning on behalf of the nuclear industry. The AIF proposal is currently under review in DSRO and IE; furthermore, it has been combined with the NRC initiated changes in l EPZ related rules and regulatory practice. l i
In order to review the EPZ Sensitivity Study, it will be necessary to identify the baseline against which comparisons are made, to identify the appropriate l criteria for making the comparisons, and to review the basic assumptions and '
the more significant aspects of the probabilistic calculations. We hsve met !
( with representatives of IE, and they have agreed to provide guidance on the l baselines and comparison criteria. They will be responsible for determining whether the study accurately portrays the principal conclusions of and technical material contained in NUREG-0396.
When the Seabrook Station Probabilistic Safety Assessment was submitted three years ago, the staff engaged in a review that was discontinued in January 1985.
This occurred due to funding restrictions on the part of the utility. The current review is intended to focus on those aspects of the PRA that contribute most to the differences in the results for public risks and doses. In this regard, it is noted that the core melt frequency of the updated Seabrook study is somewhat higher than the frequency estimated by WASH-1400 because of a more complete assessment of dependent events and component failure rates by the Seabrook study. However, the percentage of core melt scenarios of principal concern to emergency planners (i.e. , early gross containment failure and con-tainment bypass scenarios) is more than 300 times less at Seabrook, primarily due to credit granted based on the strength of the containment. Therefore, our review should carefully evaluate the assumptions and analyses regarding the behavior of the containment and the probability of the containment bypass sequences.
Several areas that have already been identified for review are:
early containment failure frequencies and the sensitivity to assumptions of loading (e.g., hydrogen detonation) and containment behavior (e.g. ,
local versus global response),
treatment of source term for bursting type containment failure, severe accident sequences involving containment bypass due to human factors and hardware problems (for example, malfunction of air operated valves due to high ambient pressure inside containment),
Harold R. Denton AUG 12 B86 i
interfacing LOCA sequences which result in core melt and simultaneous l breach of containment with consideration of procedures used for .
successful isolation of containment, !
depth of treatment of severe accident sequences resulting from external events (for example, earthquakes),
consideration of conditional probabilities.
We expect to expand and refine the above list early in the technical review process.
The Division of PWR Licensing-A will coordinate the review. DSR0 has essen-i tial expertise in the appropriate issues and techniques, and it has familiarity i with the Seabrook Probabilistic Safety Assessment and the previous review by I
the Lawrence Livermore Laboratory. We would expect that the recently formed Oversight Committee on Source Term Related Technology would be working to define its role in this effert. >
A technical assistance contract with Brookhaven National Laboratory will be used to support the staff effort. We have met with personnel from Brookhaven National Laboratory, and they have proposed a three-month effort to review the Seabrook submittal. BNL has identified six tasks necessary to assist NRC in kvaluating the technical validity of the applicant's conclusions regarding the Emergency Planning Sensitivity Study for Seabrook. Enclosure 1 contains a description of those tasks proposed by BNL. By copy of this memo we are requesting DSRO review of the proposed BNL tasks.
A meeting was held on Wednesday, August 6, with PSNH personnel to brief the NRC staff on the basic content and conclusions of their EPZ study. BNL personnel were present for this presentation.
We have informed the ACRS of the PSNH EPZ study and our review of it. By a letter to the Commission dated April 19, 1983, the ACRS requested that they be kept informed of the staff's review of the Probabilistic Safety Assessment, and this has been done to date. At this time, the ACRS has provided a letter approving only 5% power operation for Seabrook.
Preliminary discussions have been held with ACRS staff for the purpose of .
scheduling a subcommittee meeting on the EPZ study some time in September. l The applicant has requested that the technical merits of the EPZ study be reviewed with respect to its adequacy to support a change to the emergency response process. The exact nature of the change has not yet been specified.
PSNH has further requested that the review be completed on an expedited basis.
A number of internal staff meetings were held within DPL-A with members of DSRO and I&E to discuss a plan for review of the Seabrook submittal. A draft of this memo was provided to DSRO and I&E for comment. We have accepted the comments provided by I&E. With regard to DSR0 comments (Enclosure 2), we l
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! Harold R. Denton -4 AUG 121995 believe they are directed to legal and policy considerations. (In earlier discussions, OELD did indicate that the Commission regulations would permit the staff to consider the merits of an exemption to the Seabrook EPZ.) We believe the decision chart suggested by DSR0 has been essentially satisfied
, and a technical review can start. We have identified the essential technical issues which would be addressed as part of the BNL effort and the staff would be prepared to provide its evaluation by the end of October. We are proceeding with this approach. ,
A list of pertinent submittals on this subject is included in Enclosure 3.
Original signed by:
Thomasn[. yovy<
Thomas M. Novak, Acting Director Division of PWR Licensing-A
Enclosures:
- 1. Proposed Tasks
- 2. Note fm Speis dtd 8/11/86
- 3. List of References l cc. R. Vollmer F. Miraglia l R. Bernero T. Speis W. Russell E. Jordan DISTRIBUTION Docket File M, PD#5 R/F PD#5 Seabrook File I
TNovak VNoonan ERossi VBenaroya G8agchi EDoolittle SLong
- See previous concurrences PWR-A:PD#5 PWR-A:PD#5 PWR- A:PD#5 PWR-A:F0B PWR-A:EB PWR-A:AD
- Stong:aj *EDoolittle *VNoonan *VBenaroya *GBagchi *CERossi 8/5/86 8/5/86 8/5/86 8/5/86 8/5/86 8/5/86 TH k 8/ 86
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ENCLOSURE 1 i
TASKS PROPOSED FOR REVIEW OF EMERGENCY PLANNING SENSITIVITY STUDY FOR SEABROOK Task 1: System Evaluation BNL will review those portions of the Seabrook Emergency Planning Sensitivity Study related to system failure to determine the appropriateness of the cal-culated accident sequence probabilities. In particular, the probability for interfacing system LOCA will be carefully assessed to determine the potential for containment bypass. BNL will also review the probability of equipment malfunctions, personnel errors or design errors resulting in containment bypass at the time of a severe accident.
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Task 2: Containment Event Tree Review BNL will review the conditional probabilities of early containment failure given in the Seabrook submittals. In particular, the vulnerability of the Seabrook containment to uncertainties in containment loads will be carefully assessed. This task will be highly coupled to Task 3, which will assess the performance of the Seabrook containment under severe accident conditions.
Task 3: Evaluation of Containment Behavior l
The purpose of this task is to evaluate the technical validity of the applicant's !
conclusions regarding the behavior of the Seabrook containment under severe '
accident conditions. BNL will review and evaluate the relevant containment structural analyses performed by the applicant and its consultants. In addi-tion, a plant site tour and engineering audit at the applicant's (or consultants')
office will be conducted to better understand the containment analyses and design, and to identify any unique design features and/or analytical assumptions I that merit further investigation.
Based on the above review, BNL will develop an axisymmetric finite element model and perform analyses utilizing BNL's NFAP computer code to confirm the applicant's prediction of the overall capacity of the containment. Special attention will
, be given to the post-cracking behavior of the concrete which controls the shear i
failure mode of the containment. To expedite the performance of this task, BNL will utilize, to the maximum extent practical, the input parameters obtained l from the applicant's analytical models. In addition, simplified hand calcula-i tions will be performed to assess the applicant's conclusions regarding the '
behavior of selected containment penetration assemblies. Finally, BNL will perform a qualitative assessment of the applicant's seismic fragility analysis of the containment structures and components.
BNL will also support meetings with NRC management and the ACRS to describe the interim status of this review, as well as the final results.
-g.
Task 4: Review of Source Terms The appropriateness of the new source terms based on RSS methodology used in the Seabrook submittal will be reviewed.
Task 5: Site Consequence Modeling The site consequence modeling will be reviewed to determine the appropriateness of the consequence calculations presented in the Seabrook submittal. In addi-tion, any consequence calculations found necessary as a result of the work to be performed under Tasks 1-4 will be performed.
Ttr. J: Final Report A final report due by October 31, 1986 will be prepared based on the results of Tasks 1-5. The final report will address BNL's recommendations on procedures, testing or design modifications to reduce the probability of containment bypass in conjunction with a severe accident.
1 Task 7: Follow-on Effort Follow-on effort in terms of resolution of issues will be provided under this task.
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3.* % ENCLOSURE 2
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UNITED STATES
!" g hsCLEAR REGULATORY COMMISSIOh j t WASWNG TON, D. C 20355
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AUG 11 1986 NOTE T0: Tom Novak FROM: Inemis Speis
SUBJECT:
REVIEW OF THE SEABROOK EPZ SUuni tTAL I have reviewed your proposed memo to H. Denton on the Seabrook review l and provided comments in the form of markups to V. Noonan on August 8.
It is important to decide what direction NRC is going to take on this issue before a detailed technical review can start. A decision chart set up in the form of three questions is attached for your consideration.
I would recommend that you assemble a small group to assess the potential l
l approaches to the review. Four individuals, one from each, PWRL, USRO, IE and OGC, could do the job in about two weeks. Our representative is i Len Soffer, please feel free to contact him directly.
/ l lhemis Speis cc: H. Denton l%$$U # sff ,
2- .
PotentialApproachestotheReviewofthieSeabrook EPZ Submittal
- 1. Assuming that all technical infonnation received t' rom Seabrook is correct, can NRC reduce the Seabrook LPl or evacuation zone below the 10 mile limit under current regulations and established regulatory practice?
If answer is No, go to Q-2.
If answer is Yes: ,
i What information is important for the decision?
- What additional information is needed from PSNH? i
-l'
- 2. Can NRC use a risk based criteria to justify a reduction in EPZ or evacuation zone for Seabrook without "rulemaking" or granting an exemption?
If answer is No - Seabrook snould either join the ongoing rulemaking j or go to y-3. !
If answer is Yes:
What information is important for the decision?
What additional information is needed for PSNH?
- 3. What basis could NRL have for granting an exemption from existing ;
emergency planning requirements for Seabrook?
a.) Is the Seabrock plant significantly different from other PWRs with large dry containments with respect to Emergency Planning requirements?
If answer is No, go to Q-3b.
If answer is Yes:
What information is important for the decision?
What additional information is needed from PSNHY b.) Is there an "ininediate need" for Seabrook, that would justify exempting it from current EPZ requirements while the rule change is underway?
If answer is No - give up!
If answer is Yes:
What information is important for the dectrion?
What additional infonnation is needed from PSNH7
R !
s ENCLOSURE 3
References:
- 1. George S. Thomas to Vincent S. Noonan letter dated July 29, 1986, Seabrook Station Probabilistic Safety Study Update.
- 2. John DeVincentis to Vincent S. Noonan letter dated July 21, 1986, Seabrook Station Probabilistic Safety Assessment Update.
- 3. Seismic Fragilities of Structures and Components of the Seabrook Generating Station, Units 1 & 2, prepared by NTS Engineering, Long Beach, CA for Pickard, Lowe and Garrick, Inc. and New Hampshire Yankee Division, Public Service Company of hew Hampshire, Seabrook, New Hampshire, June 1986. Technical Report No. 1589.01.
I
- 4. Seabrook Station Emergency Planning Sensitivity Study, prepared by Pickard, Lowe and Garrick, Inc. , Newport Beach, CA for New Hampshire Yankee Division, Public Service Company of New Hampshire, Seabrook, New Hampshire, April 1986. PLG - 0465.
- 5. John DeVincentis to George W. Knighton letter dated January 30, 1984, Seabrook Station Probabilistic Safety Assessment Main Report and )
Summary Report. l l
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- 6. Seabrook Station Risk Management and Emergency Planning Study, prepared !
by Pickard, Lowe and Garrick, Inc., Newport Beach, CA for New Hampshire Yankee Division, Public Service Company of New Hampshire, Seabrook, New l Hampshire, December 1985. PLG - 0432.
)
1 7.
Seabrook Station Probabilistic Safety Assessment (Summary Report and 6 volumes), prepared by Pickard, Lowe and Garrick, Inc. , Newport Beach, CA for Public Serv',ce Company of New Hampshire, Manchester, New Hampshire and Yankee Atomic Electric Company, Framingham, MA, December 1983.
PLG - 3000.
- 8. Seabrook Station Probabilistic Safety Assessment Technical Summary Report, prepared by Pickard, Lowe and Garrick, Newport Beach, CA for Public Service Company of New Hampshire, Manchester, New Hampshire and Yankee Atomic Electric Company, Framingham, MA, June 1984.
PLG - 0365.
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