ML20054D284
| ML20054D284 | |
| Person / Time | |
|---|---|
| Issue date: | 04/01/1980 |
| From: | Ahearne J NRC COMMISSION (OCM) |
| To: | Advisory Committee on Reactor Safeguards |
| Shared Package | |
| ML19239A281 | List: |
| References | |
| FOIA-81-405, TASK-1.C.1, TASK-2.K.1, TASK-3.D.3.4, TASK-TM NUDOCS 8204220526 | |
| Download: ML20054D284 (1) | |
Text
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- o, UNITED STATES
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( ;3 NUCLEAR REGULATORY COMMISSION
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T s%,.. g wAsmucion. o. c.roscs April 1, 1980 NECUVfD
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CHAIRMAN f,Q.j
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f Dr. Milton S. Plesset u,3 y Chairman, Advisory Comittee on ADpis$o. EN'iUE 7
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U. S. Nuclear Regulatory Comission Washington, D. C.
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{b esset:h Dear Dr.
I would appreciate receiving additional information about some of the ACRS coments which you sent me in your letter of March 11,1980, con-
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cerning NTOL items from Draft 3 of the NRC Action Plan.
p 1.
Which of the items from the list in Part 1. Requirement (11). Item f
II.K.1 does the Comittee consider to be useful, which to be of marginal merit, and which to be wrong?
c.
2.
In comenting on Part 1 Requirement (13), Item III.D.3.4 the E.
Comittee noted, "The THI incident indicates that existing require-E ments to protect the occupants of the control room against radiation
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may not be adequate, particularly with respect to leakage control t
and arrangement of air intakes." Does the Comittee have any L
specific suggestions as to how these requirements s,hould be upgraded?
p 3.
Which of the items from Part-2, Requirement (4), Item I.C.1 doet h,
the Comittee consider to be useful, which to be of marginal merit.
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and which to be wrong?
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Thank you.
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Sincerely,
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Jc n F. Ahearne b
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cc: Comissioner Gilinsky I:
Comissioner Kennedy
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Conmissioner Hendrie Commissioner Bradford E
SECY OPE k.
EDO NRR 8204220526 eii112 PDR FOIA SHOLLY81-405 PDR l
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[2-H C V APR 1 1980 HEHORANDUM FOR: Chairman Ahearne FR0ti:
William J. Dircks Acting Executive Director for Operations
SUBJECT:
ACRS REPORT ON NEAR-TERil OPERATING LICENSE REQUIREMENTS Enclosed is a point-by-point response to the March 11, 1980 ACRS Report on ticar-Tenn Operating License Items from Draft 3 of NUREG-0660,
.NRC Action Plan Developed as a Result of'the THI-2 Accident, g-;sc)T.R WFE
)/ Acting Executive Director William J. Dircks for Operations
Enclosure:
as stated cc: Cocraissioner Gilinsky Cocraissioner Kennedy Cocnissioner Hendrie
[# Co::raissioner Bradford ACRS Distribution:
DSS R/F Central File R Minogue NRR R/F V Stello ED0 D Muller EDO r/f R Budnitz G Ertter(#8549,8581)
T Rehm M Groff H Berkow DgJf [ 3 T Schultze W Russell H Denton D Ross E Case D Eisenhut D
R Mattson PDR
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W Minners W Dircks K Cornell OPE OGC orrice
_,DSg DSS NRR NRR EDO WffinneY:ah:tsRMattson ECase HDenton WDircks
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37 /80
- 1. ACRS COMMENT Part 1, Requirement (3), Item I.B.1.2, " Evaluation of Organization and Management Imorovements of Near-Term Operating License Applicants."
The Comittee is concerned about the specification as an NTOL requirement of an " Interoffice NRC review of licensee management to determine organi-zational and managerial capabilities, using internal NRC draft criteria pending development of formal criteria." If it is to be assumed that this requirement refers to utility management (rather than plant management),
then it appears that assurance of competent management should be obtained as soon as feasible for all utilities that are operating power reactors, independently of NTOL activity. Coupling this determination to an operating license (0L) appears logical only if the reactor is the first to be operated by the applicant..
The Staff has indicated that the criteria for judging management capability are in an early state of development. The ACRS recommends that due regard be given to the need for a learning period in developing and applying the criteria, and that there be a continuing effort to make tha criteria as clear as possible to those organizaations.being evaluated.
RESPONSE
The staff does not agree with this ACRS coment.
First the Comittee assumes that the requirement refers to utility management rather than plant manage-ment.which is not correct.
The scope of the evaluations will include onsite and offsite organizations, both management and technical, including the radiological protection organization.
Evaluation of an applicant's management and organization has been a part of the staff's normal operating license review but not in the depth now intended. The additional review being given to the near term OLs is an appropriate interim measure for new units, even if they are the second at a site, until the revised criteria (see Action Plan Item I.B.1.1, Organization and Management Long-term Improvements) have been developed.
Because the criteria are being used in the NTOL reviews in,an early state of l
development, they are not suitable to be imediately and broadly applied to all licensees, nor are they being applied rigidly to the new licensees.
The' NRC review of licensee.mnagement for the next few operating licenses provides a unique opportunity for a learning period in developing and applying such criteria.
This learning period should serve to strengthen and clarify the final criteria before they are applied to all operating plants and all subse-quent OL applicants.
2.
ACRS COMMENT Part 1, Requirement (4), Item 1.B.1.2, " Evaluation of Organization and Ma'nagement Improvements of Near-Term Operating License Acolicants."
The ACRS endorses the objective of improving the engineering capability onsite, but has not studied the criteria that will be used to qualify the group.
RESPONSE
No Comnent. The Staff will consult with the ACRS during the final develop-ment of the cri,teria discussed in Item I.B.1.1.
3.
ACRS COMMENT Part 1, Requirement (6), Item I.C.7, "NSSS Vendor Review of Procedures."
With respect to Emergency Procedures, the ACRS recommends that Architect-Engineers (AE) or the AE component of the operating utility also be re-quired to review and verify the adequacy of such procedures in the context of accuracy and completer.ess to meet emergency conditions, including the specifications of actions to deal with inadequacies in the single failure criterion.
RESPONSE
We do not agree with the ACRS comment at this time. The present OL review of emergency procedures is being 1.imited to the NSSS vendor, since the reactor supplier has the greatest knowledge of the response of the reactor to trans-ients and the requirements for protecting the core. Review by the AE may also be desirable, and as indicated in the Action Plan, the staff wil,1 decide whether to continue or expand this requirement to include procedure review by the AE after trial use in a few cases and in light of the more comprehensive long term program for upgrading procedures (see Action Plan Item I.C.9).
Not involving the AEs at this time also reflects our concern that industry man-poser not be totally diverted to low payoff activities at the expense of other activities of higher safety significance.
Adding the AE review of procedures to the NSSS vendor review would not significantly increase the safety payoff of the review, in our current judgment.
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4.
ACRS COMMENT Part 1,. Requirement (7), Item.I.C.8, " Pilot Monitoring of Selected Emergency Procedures for Near-Term Ooeratino License Acolicants."
l To ensure against relaxation of continuous vigilance to meet emergencies, l
the Committee reconnends nonscheduled random checking of operating person-nel in respect to verifying their ability to meet unanticipated accident conditions.
RESP 0$SE It is assumed the ACRS does not intend this be a separate NT0L requirement.
Personnel qualification and requalification requirements, including periodic simulator training and plant drills, are addressed in other parts of the Action Plan. (See I. A.2.5 and I. A.2.6.)
6 m
. Although the requirements for drills are now being developed and are not scheduled to be issued until January,1981, the current concept is that i
the type of drill would not be announced, but the time of the drill would be scheduled so that the shift crew could be ' supplemented during the drill to assure minimal effect on operations or scheduled after the normal shift.
5.
ACRS COMMENT Part 1, Requirement (11), Item II.K.1, "IE Bulletins on Measures to Mitigate Small Break LOCAs and Loss of Feedwater Accidents."
This list includes some items which are useful, some which are of marginal merit and some which may, upon deeper analysis, turn out to have been wrong.
Among those that deserve more careful analysis are: (a) criteria for early RCS pump trip; (b) criteria for HPSI termination; (c) automatic PORY blocking; (d) several requirements that increase scram frequency; (e) subcooling meters (versus voidmeters); etc.
Each of these is a subject in' itself, deserving deliberate study.
RESP 6NSE We agree with the ACRS that the criteria for early RCS pump trip a.
deserve further study.
The Action Plan Item 5 of Table C-3 will be revised in the next version to provide for continued study of these criteria to be completed by January 1,1981.. Implementation, if any, will be required by January 1,1982 instead of 1981.
b.
The current criteria for HPSI termination have been thoroughly analyzed by the staff and the NSSS vendors, who propose no changes.
c.
An overall safety assessment of the automatic isolation of the PORV is to be completed by January 1,1981 (see Item 2 of Table C-3 in the Action Plan).
To accomodate the ACRS comment, the implementation of the re'quirement to install an automatic isolation system will be changed from January 1,1981 to July 1,1981 and after the studies are completed (see Item 1 of Table C-3), if the studies confirm such change to be necessary.
d.
Some modifications have been required that have increased the fre-l quency of scram of B&W plants.
However, the data now available indicate that the increase was modest and the frequency of scram in B&W plants is approximately that of Westinghouse plants. The design sensitivity of B&W plants is being studied further (see Action Plan Item II.E.5) and design l
changes may be required.
Futhermore, B&W plants are free to suggest return to former PORV control methods with approximate safety justification.
e.
Although the neans of indicating inadequate core cooling are not limited to subcooling (see Action Plan Item II.F.2), subcooling meters (as conpared to void meters) are a more useful indication since they provide a w
continuous monitoring of the margin (which void meters do not). Thus they indic:te when cooling conditions are deteriorating and provide an immediate indication of when thermodynamic conditions are in the range where voids are possible (void meters would require a significant void fraction to bepresent). ^ Investigation of the application of other instuments (such as gamma densimeters in the RCS loops, neutron detectors for core voids, and capacitive level probes) to large reactors is continuing (See Action Plan Item I.D.5).
6.
ACRS COMMENT Part 1, Requirement (12), Item II.K.3, " Final Recommendations of B&O Task Force."
Refer to the ACRS report dated March 11, 1980 on the Bulletins and Orders Task Force report, which documents some of our concerns.
RESPONSE
The concerns contained in the March 11 ACRS report on The Bulletins and Orders Task Force report are discussed individually, below.
6a. ACRS COMMENT Reactor Coolant Pump Trip and High Pressure Injection (HPI) Termination Criteria: The NRC Staff has required pronpt trip of the reactor coolant pumps in the event of a small-break LOCA. Recent transients at some operating plants have resulted in RCP trip for non-LOCA events and, in some cases, the use of the NRC approved procedures for HPI termination have resulted in PORY or safety valve actuation due to overfilling of the primary system.
The NRC Staff should, in conjunction with the licensees, review the criteria for HPI termination and reactor coolant pump trip to reduce unnecessary challenges to the pressurizer safety valves and pre-vent unnecessary trips of the reactor coolant pungs which may. increase the difficulty in establishing uninterrupted core cooling.
RESPONSE
See responses 5a and 5b to ACRS Comment 5, above [Part (1), Requirement (11),
Item II.K.1].
6b. ACRS COMMENT Fced-and-Bleed Cooling of the Primary System: At the March 4, 1980 Sub-committee meeting, the NRC Staff said that there are presently no require-ments for the use of feed-and-bleed cooling for decay h, eat removal.
The Committee believes that the availability of a diverse heat removal path such A _
as feed and bleed is desirable, particularly if all secondary-side cooling is unavailable.
The ACRS has established an Ad Hoc Subcommittee to review this natter.
RESPONSE
The staff believes that desirability of a diverse heat removal such as feed-and-bleed should be investigated and the Action Plan will be revised to in-clude the development of such a study.
The staff participated in an ACRS Subcommittee meeting on this subject on March 26 and will work with the Committee to develop a nutually acceptable study program.
_6c. ACRS COMMENT Reductior, of Challenges to the PORVs in B&W Plants:
As a result of the TMI-2 accident, the NRC Staff has required that all B&W plants raise the PORY actuation setpoint and lower the High-pressure reactor trip setpoint in order to reduce the number of challenges to the PORV.
While recent B&W operating reactor experience indicates that the PORV challenge rate has been reduced, there has been a corresponding increase in the number of reactor scrams.
The Committee notes that an increase in the scram rate increases the probability of a deleterious impact on safety, and recommends that the NRC Staff continue to evaluate the overall impact of the above action on plant safety.
RESPONSE
See response 5d to ACRS Conment 5, above (Part 1, Requirement (11), Item II.K.1]
6d. ACRS COMMENT
,e Potential Unreviewed Safety Question with Regard to Automatic Initiat' ion of the Auxiliary Feedwater System: Several utilities have raised the issue of a potential unreviewed safety question with regard to automatic initiation of the AFW system, in the event of a main steamline break inside containment.
This issue should be reviewed.
RESPONSE
W Those licensees who have raised the issue of the effect of automatic
, e agree.
AFW initiation during a main-steamline-break accident have been issued letters requesting an analysis of the' potential unresolved safety issue.
June,1980 (see Action Plan Item II.E.1.2).These analyses are schedul
. 6e. ACRS COMMENT The Task Force has recommended that the vendor methods used for small break LOCA analysis should be revised, documented ~ and s;bmitted for NRC review, and that plant specific calculations using NRC approved methods should be provided thereafter.
The NRC Action Plans also i iclude an item which recommends that the NRC develop and issue a position on required conservatisms in small break calculations.
The Committee believes that the schedule used for developing a revised NRC approach to small break calculations should, if practical, be made conpatible with the schedule required of the NSSS vendors for revising their small breeak models.. This should lead to a more efficient use of analyses.
This implies some increased flexibility in the schedule.
RESPONSE
The evaluation of small-break analysis uncertainties and conservatisms is scheduled to be completed by vendors by July,1980 (See Action Plan item II.E.2.3).
A Cc: mission paper on proposed changes resulting from the evaluations, if needed, is scheduled to be comp 1; cad by September,1980.
The implementation of any changes can then be made consistent with the January,1982 schedule for revisions to vendor methods for small-break analyses (Action Plan Item 31 of Table C-3).
6f. ACRS COMMENT With regard to the schedule proposed for the implementation of 'the recommendations, The Conmittee believes that the orderly and efffective implementation and the appropriate level of review and approval by the NRC staff will require a somewhat more flexible, and in some cases more extended, schedule than is implied by the Task Force reports.
RESPONSE
Consi,deration of the B&O Task Force recommendations in light of the other requi_rhments included in the Action Plan and the limited resources available to both the industry and staff has resulted in some changes in schedule l
which are reflected in Table C-3 of Oraft 3 of the Action Plan. Further changes may be made in the next revision of the plan.
7.
ACRS COMMENT Part 1 Requirement,(13), Item III.D.3.4, " Control Room Habitability."
The ACRS notes that this item merely sets a goal to " confirm conpliance with existing Regulatory Guides and Standard Review Plan...."
The TMI incident indicates that existing requirements to protect the occupants of the control room against radiation may not be adequate, particularly with respect to leakage control and arrangecent of air intakes.
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RESPONSE
Licensees and applicants are now being required to provide for the accurate determination of the airborne iodine concentration in areas where plant personnel might be present during an accident and to also take corrective actions based on a radiation and shielding design review to assure adequate access to vital areas in the event of an accident.
(See Action Plan Item 111.D.3.3) In the longer term the design criteria for the control room area ventilation system will be reviewed (see Action Plan Item III.D.1.3) and the habitabililty of control rooms under degraded core conditions will be evaluated in the rulemaking on degraded core considerations (see Action
. Plan Item II.B.8).
A'RS COMMENT 8.
C Part 2, Requirement (45), Item I.C.1, "Short-Term Accident Analysis and
_ Procedure Revision."
The comments in the first sentence concerning Part 1, Requirement (11) regarding the need for careful analysis apply to a number of unresolved items in this requirement.
RESPONSE
See Response to ACRS Coment 5, above [Part 1, Requirement (11)].
9.
ACRS CDMMENT Part 2, Requirement (15), Item II.E.4.1, " Containment Dedicated Penetrations."
The ACRS recomends that, in design and location o'f penetrations for the recombiner, the Staff pay particular attention to the possibility of hy-drogen accumulation at high points in the containment or containment cogarte.ents.
RESPONSE
~
Natural diffussion and the return air fans, fan coolers or containment sprays in the containments that are now required to have recombiners will provide adequate mixing for the gases which are relatively slowly generated by radiolytic deconosition br small amounts of metal water reaction.
The question of control of larger and more rapidly generated amounts of hydrogen will be specifically considered in the long term rulemaking on degraded cores (see Action Plan Item II.B.8).
Em>
f 10.
ACRS COMMENT Part 3, Requirement (4), Item III.A.3.1, " Role of NRC in Emergency Preparedness."
We believe that the responsibility for handling an emergency should be clear and undiluted, and should rest with the utility.
The NRC should be fully informed, prepared to intervene when necessary for the public health and safety, but should not, as a rule, take over responsibility in the event of an accident.
This issue r:ust be resolved.
RESPONSE
~
We believe that this issue has been resolved in connection with the Cor: mission's consideration of SECY 80-35 at its meeting on February 7,1980.
- 11. ACRS COMMENT In considering these matters, the ACRS also examined those NTOL~ requirements that have already been issued in the NRC letters of September 27, 1979 and this, group are several requirements related t6 improved systems for measuring effluent releases. Although the Committee endorses these requirements, it believes that more attention needs to be directed to assuring:
That samples collected are representative with emphasis on the location a.
and nature of the sample collector and the length, diameter, and specific nature of the sampling lines.
b.
The adequacy and reliability of the performance of the associated sampling and monitoring equipment.
, RESPONSE During the routine inspection program, IE Radiation. Specialist Inspectors examine.the licensee's sampling systems for technical adequacy, including:
a) Review of as-built drawings to determine consistency with design -
, requirements as presented in the FSAR and b) A review of the licensee's determination of the system sample and collection efficiencies, particularly for gaseous halogens and particulates. The technical basis for this inspection review is presented as regulatory guidance in Regulatory Guide 1.21, " Measuring, Evaluating, and Reporting Radioactivity in Solid Wastes and Releases of Radio-active Materials in Liquid and Gaseous Effluents from Light-Water-Cooled Nuclear Power Plants." Regulatory Guide 1.21 endorses the general principles of ANSI N13.1-1969, " Guide to Sampling Airborne Radioactive Materials in Nuclear Facilities" as being' generally acceptable and providing adequate bases for the design and conduct of monitoring programs for airborne effluents.
The design review of these systems is addressed in Standard Review Plan, l
Section 11.5, " Process and Effluent Radiological Monitoring and Sampling Systems", which also endorses the ANSI N13.1 Standard and calls for a system design to include provisions for reducing plate-out in sample lines.
l NRR will soon issue a letter that clarifies the needs t6 assure that samples are representative and that the associated sampling and monitoring equip-ment is adequate and reliable.
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The ANSI standard provides quantitative guidance on system design; however, the potential problem of chemically reactive forms of radioisotopes, especially radiciodine, is only qualitatively acknowledged.
Specific guidance on the evaluation and determination of the extent of sample have deposition / reactivity is not presented.
The NRC licensing review and the IE inspection review evaluate the adequacy of the licensee's sampling system / program.
However, the potential problems associated with sample line depositon/ reactivity is an aspect of sarpling that is in need of additional guidance and will be considered by the staff for f ollow-up evaluation.
12.
ACRS COMMENT The Committee wishes to comment at this time on two items in the Action Plans in order to recommend the initiation of actions which relate to the NTOL plants.
In the Committee's opinion, the issuance of aa operating license should not be contingent on completion these matters.
In its letter of December 13, 1979 on the TMI-2 Lessons Learned Task Force Report, the ACRS supported the Integrated Reliability Evaluation Program (IREP). However, the ACRS went on to state, "The Committee does not agree that the proposed IREP will fully satisfy the need.
The ACRS recommends that the NRC develop a program in which licensees, acting individually or jointly, develop reliability assessments of their plants in addition to the NRC IREP, which would be performed concurrently."
The ACRS believes that, on an expedited but practical schedule, the NTOL
. plant owners, as well as current licensees, should be required to perform studies of the type referered to above.
RESPON5E The decision as to the division of work on reliability assessment between the NRC and the industry will be based on the results of the initial six l
plant-Integrated Reliability Evaluation Program (see Action Plan Item II.C.1)
In parallel with the six plant study, discussions will be held with reactor i
owners and industry groups as to possible efforts by industry in IREP.
A paper that discusses the alternatives is scheduled to be submitted to the Commission in October 1980 (see Action Plan Item II.C.2).
k3.
ACRS COMMENT In its letter of December 13, 1979, the ACRS supported the recommendation of the Lessons Learned Task Force concerning design features for core-damage and core-melt accident. The ACRS futher recommended that design studies 4
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. be required from licensees.of possible hydrogen control and filtered-vent be given to naking a timely decision on possible interim measures condenser containments.
NTOL plants.
The ACRS recommends initiation of such studies for
RESPONSE
An interim rule and notice of intent to conduct rulemaking is scheduled to be issued by July,1980.
In drafting these documents the staff is now considering including a requirement that licensees and applicants provide design studies of possible hydrogen control and filtered-venting systems for containments.
(See Action Plan Item 11.B.8.)
and evaluation of possible concepts for hydrogen control in ice-condenserThe s containments are presented as part of the Commission Paper SECY 80-107; Proposed Interim Hydrogen Control Requirements for Small Containments (Se Action Plan Item II.C.7.)
'2)
, ACRS COMMENT The ACRS has noted in previous letters that it is important th'at the improve-ments in safety proposed as a result of the Three Mile Island accident be -
safety receive proper priority. considered in a broad perspective and th diversion of reesources needed to deal with NT0L related activities no produce neglect of problem areas which should have a high priority. ~ The Committee expects to comment on this in detail when it reports on the NRC Action Plans.
RESPONSE
The scheduling and implementation of requirements in the TMI Action plan gre being developed with consideration of the relative priority of TMI te' lated and other safety issues.
The staff is now developing resource schedules of this work and other programs to attempt t use of the available resources to obtain the greatest effective increase in safety.
Action Plan. This information will be presented with the next re' vision of the The possible diversion of resources of both the staff and the industry due i
to the NT0L requirements, both individually and as a whole, was carefully j
considered in developing the list.
The industry comments on the list of NTOL requirements, which were solicited at the suggestion of the Commission also emphasized this concern.
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