ML20138G351
| ML20138G351 | |
| Person / Time | |
|---|---|
| Issue date: | 12/10/1985 |
| From: | Fraley R Advisory Committee on Reactor Safeguards |
| To: | Dircks W NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| References | |
| ACRS-R-1172, NUDOCS 8512160298 | |
| Download: ML20138G351 (13) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
I ADVISORY COMMITTEE ON REACTOR SAFEGUARDS
/
O WASHINGTON, D. C. 20555 December 10, 1985 MEMORANDUM FOR:
William J. Dircks Executive Director for Operations FROM:
R. F. Fraley Executive Director, ACRS
SUBJECT:
THIRD SET OF ACRS COMMENTS ON THE PRIORITIZATION OF THE REMAINING GENERIC ISSUES l
During its 308th meeting, December 5-7, 1985, the ACRS reviewed the adequacy of the proposed priority rankings for a group of generic issues identified in the attached Table 1, and its coments are contained in the following attachments.
- Attachment I lists those items for which the ACRS agrees with the
'l priority rankings proposed by the NRC Staff.
- Attachment 2 includes a list c t tems for which the ACRS agrees with the priority rankinoe tyt ed by the NRC Staff, but has coments.
- Attachment 3 contains a list of items for which the ACRS disagrees with the NRC Staff's proposed priority rankings along with the reasons therefor.
Coments on Generic Issue 103, " Design of Probable Maximum Precipita-tion," have been deferred pending additional review by the ACRS.
It is requested that the NRC Staff provide written responses to the ACRS coments identified in Attachments 2 and 3.
The ACRS will continue its review of the adequacy of the proposed priority rankings for the remaining generic issues when they become, available.
Attachments: As Stated x
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TABLE 1 3
THIRD GROUP 0F NEW GENERIC ISSUES 4
REVIEWED BY THE ACRS DURING THE 308TH, DECEMBER 5-7, 1985, MEETING i
J, GENERIC ISSUE TITLE PRIORITY RANKINGS PROPOSED BY NUMBER THE STAFF 30 Potential Generator DROP Missiles - Generator Rotor Retaining Rings 37 Steam Generator No need for separate resolution Overfill and Combined because the principal concerns Primary and Secondary of this issue are covered in USI Blowdown A-47, " Safety Implications of Control Systems," and Generic Issue I.C.1, "Short-Term Acci-dent Analysis and Procedures Revision".
54 Survey of Valve No need for separate resolution Operator Related because the principal concerns Events During 1978, of this issue are covered in 1979 and 1980 the Generic Issue II.E.6.1, "In situ Testing of Valves".
55 Failure of Class IE DROP Safety-Related Switchgear Circuit Breakers to Close on Demand 67 Steam Generator Staff Actions:
67.2.1 Integrity of Steam REGULATORY IMPACT ISSUE Generator Tube Sleeves 3 6 67.3.1 Steam Generator Overfill Covered 1 USI A-47, " Safety Implications of Control Systems,"
and Generic Issue I.C.1, "Short-Term Accident Analysis and Procedures Revision".
67.3.2 Pressurized Thermal Shock Covered in USI A-49, " Pressurized Thermal Shock Program" r
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_2 TABLE 1 (Cont'd)
GENERIC ISSUE TITLE PRIORITY RANKINGS PROPOSED BY NUMBER THE STAFF 67.3.3 Improved Accident Monitor-RESOLVED ing (Being Implemented) 67.3.4 Reactor Vessel Inventory Covered in Generic Issue II.F.2, Measurement
" Instrumentation for Detection of Inadequate Core Cooling" (Being Implemented) 67.4.1 Reactor Coolant Pump Trip Covered in Generic Issue II.K.3.5,
" Automatic Trip of Reactor Coolant Pumps" (Being Implemented) 67.4.2 Control Room Design Covered in Generic Issue I.D.1,
" Control Room Design Reviews" i
(BeingImplemented) 67.4.3 Emergency Operating Pro-Covered in Generic Issue I.C.1, cedures "Short-Term Accident Analysis and Procedures Revision"(Being Implemented) 67.5.1 Reassess Radiological LICENSING ISSUE Consequences 67.5.2 Evaluation of Steam LICENSING ISSUE Generator Tube Rupture Design Basis 67.5.3 Secondary System Isolation DROP l
67.6 Organizational Responses Covered in Generic Issue III.A.3, " Improving NRC 1
i Emergency Preparedness" 67.7 Eddy Current Tests MEDIUM 67.8 Denting Criteria REGULATORY IMPACT ISSUE 67.9 Reactor Coolant System Covered in USI A-45, " Shutdown Pressure Cont.ol Decay Heat Removal Requirements,"
l and Generic Issue I.C.1
O
,. TABLE 1 (Cont'd)
GENERIC ISSUE TITLE PRIORITY RANKINGS PROPOSED BY NUMBER THE STAFF 67.10 Supplemental Tube LICENSING ISSUE Inspections 85 Reliability of Vacuum DROP Breakers Connected to Steam Discharge Lines Inside BWR Containments 87 Failure of HPCI Steam HIGH Line Without Isolation 91 Main Crankshaft Failures RESOLUTION HAS BEEN IDENTIFIED in Transamerica Delaval Emergency Diesel Generator 94 Additional Low-Temperature-HIGH Over-Pressure Protection for Light Water Reactors 97 PWR Reactor Cavity RESOLVED Uncontrolled Exposures 99 RCS/RHR Suction Line HIGH Interlocks on PWRs 101 BWR Water Level HIGH Redundancy 105 Interfacing Systems HIGH LOCA at BWRs 112 Westinghouse RPS REGULATORY IMPACT ISSUE Surveillance Frequencies and Out-of-Service Times 119 Piping Review Committee REGULATORY IMPACT ISSUE Recommendations B-50 Post-0perating Basis REGULATORY IMPACT ISSUE Earthquake Inspection (LOW)
B-59 N-1 Loop Operation in REGULATORY IMPACT ISSUE BWRs and PWRs (RESOLVED)
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ATTACHMENT 1 LIST OF GENERIC ISSUES FOR WHICH THE ACRS AGREES WITH THE PRIORITY RANKINGS PROPOSED BY THE NRC STAFF GENERIC ISSUE NO.
TITLE 30 Potential Generator Missiles - Generator Rotor Retaining Rings 67 Steam Generator Staff Actions:
67.2.1 Integrity of Steam Generator Tube Sleeves 67.3.2 Pressurized Thermal Shock 67.3.3 Improved Accident Monitoring 67.3.4 Reactor Vessel Inventory Measurement 67.4.1 Reactor Coolant Pump Trip 67.4.2 Control Room Design 67.4.3 Emergency Operating Procedures 67.5.1 Reassess Radiological Consequences 67.5.2 Evaluation of Steam Generator Tube Rupture Design Basis 67.5.3 Secondary System Isolation 67.7 Eddy Current Tests 67.8 Denting Criteria 67.9 Reactor Coolant System Pressure Control 67.10 Supplemental Tube Inspections 85 Reliability of Vacuum Breakers Connected to Steam Discharge Lines Inside BWR Containments
ATTACHMENT 1 (Cont'd)
GENERIC ISSUE N0.
TITLE 87 Failure of HPCI Steam Line Without Isolation 91 Main Crankshaft Failures in Transamerica Delaval Emergency Diesel Generators 9?
Additional Low-Temperature-Over-Pressure Protection for Light-Water Reactors 105 Interfacing Systems LOCA at BWRs 112 Westinghouse RPS Surveillance Frequencies and Out-of-Service Times 119_
Piping Review Committee Recommendations
ATTACHMENT 2 LIST OF ITEMS FOR WHICH THE ACRS AGREES WITH THE PRIORITY RANKINGS PROPOSED BY THE NRC STAFF, BUT WITH COMMENTS Generic Issue No:
37
Title:
Steam Generator Overfill and Combined Primary and Secondary Blowdown Priority Ranking Proposed by the NRC Staff:
No need for a separate resolution as the principal concerns of this issue are covered in USI A-47, " Safety Implications of Control Systems," and Generic Issue I.C.1, "Short-Term Accident Analysis and Procedures Revision."
ACRS Comments:
The ACRS had recommended previously in a March 13, 1985 letter from D. Ward to W. Dircks that the steam generator overfill issue be designat-ed as a separate issue and the appropriate resources be applied to assure achievement of a near-term solution. The ACRS has been meeting with the NRC Staff and discussing these issues.
At the present time, the ACRS does not see how USI A-47 and TMI Action Plan Item I.C.1 will cover all relevant aspects of this problem.
The ACRS will reserve judgment on this until the NRC Staff work has progressed further.
_2 ATTACHMENT 2 (Cont'd)
Generic Issue Mo:
54
Title:
Survey of Valve Operator Related Events During 1978, 1979, and 1980.
Priority Ranking Proposed by the NRC Staff:
Covered in Generic Issue II.E.6.1, "In situ Testing of Valves" - No need for separate resolution.
ACRS Comments:
The Staff has assured that the safety issues identified in this item will be addressed in the resolution of Generic Issue II.E.6.1, "In Situ Testing of Valves" (MEDIUM priority ranking). The ACRS agrees that a separate resolution is not required, but would like to be kept informed of adjustments to the scope of Generic Issue II.E.6.1 to accommodate the broader and more general scope and implications of Generic Issue 54. Given the Staff's own pronouncements concerning the importance of motor-operated valves as contributors to core melt and the intention to combine the issue, the ACRS is surprised that the combined scope has not been given a higher priority ranking.
As you know, an ACRS Subcommittee has been looking into the reliability of motor-operated valves for the past several months and is preparing a report for Consnittee consideration.
The ACRS may have further comments on this matter later.
L
7 4
ATTACHMENT 2 (Cont'd)
Generic Issue No:
55
Title:
Failure of Class IE Safety-Related Switchgear Circuit Breakers to Close on Demand Priority Ranking Proposed by the NRC Staff:
DROP ACRS Comments:
After an exhaustive but much too narrow analysis (the only fix seriously considered was increased inspection and improved maintenance),
the Staff concluded that the fix investigated was not cost-effective. The ACRS agrees that this issue should be dropped, not because of the analysis performed, but b,ecause the issue is, or certainly should be, subsumed in an area of principal importance by USI A-44, " Station Blackout."
Generic Issue No:
67.3.1
Title:
Steam Generator Overfill Priority Ranking Proposed by the NRC Staff:
No need for separate resolution as the principal concerns of this issue are covered in USI A-47, " Safety Implications of Control Systems," and Generic Issue I.C.1, "Short-Term Accident Analysis and Procedures Revision."
ACRS Comments:
See comments on Generic Issue 37.
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ATTACHMENT 2 (Cont'd)
Generic Issue No:
67.6
Title:
Organizational Responses Priority Ranking Proposed by the NRC Staff:
Covered in Generic Issue III.A.3., " Improving NRC Emergency Preparedness" ACRS Comments:
This issue appears to be covered in NUREG-0660, "NRC Action Plan Developed as a Result of the TMI-2 Accident." However, NUREG-0660 was issued in May 1980 and the recommendations in Generic Issue 67.6 were originally made at the latter part of 1982. The 1982 recommendations should be evaluated in detail to ensure that all significant recommendations are factored into the TMI Action Plan Item III.A.3.
Generic Issue No:
99
Title:
RCS/RHR Suction Line Interlocks on PWRs Priority Ranking Proposed by the NRC Staff:
HIGH ACRS Comments:
The ACRS agrees that this may be an important
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safety issue and should be investigated expedi-tiously. The ACRS recommends that before a final decision is made on a fix a more thorough analysis of root causes be made. This should include a re-examination of the original justification for the requirement.
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ATTACHMENT 2 (Cont'd)
Generic Issue No:
101
Title:
BWR Water Level Redundancy Priority Ranking Proposed by the NRC Staff:
HIGH i
ACRS Comments:
The ACRS agrees that the problem of assuring reliable water level indication in BWRs should receive prompt attention. The ACRS suggests, however, that the title of the issue be revised lest those responsible for its fix be led to believe that it is " redundant water level" that is of concern rather than a reliable system for water level indication.
Generic Issue No:
B-50
Title:
Post Operating Basis Earthquake Inspection Priority Ranking Proposed by the NRC Staff:
The NRC Staff-assigned " Low" priority ranking would in all likelihood prevent any resources from being applied to this issue in the fore-seeable future. The ACRS believes that it would be wise to devote a modest level of effort to this problem. Were a plant to experience an OBE, the NRC Staff would be under considerable pressure to develop inspection requirements within a very short time. How-ever, the operating utilities seem not to be pressing for resolution.
e ATTACHMENT 2(Cont'd)
Generic Issue No:
B-59
Title:
N-1 Loop Operation in BWRs and PWRs Priority Ranking
. Proposed by the NRC Staff:
RegulatoryImpactIssue(Resolved)
ACRS Comments:
The ACRS agrees with the proposed priority ranking subject to the confirmation of the following by the Staff:
- It should be ensured that procedures are in place and adequatt to prevent " cold-
^
slugging" and resultant fast power excur-sion.
- It should be verified that pumps have been suitably protected against start and run using both isolation valves closed with safety grade equipment and annunciation.
Several thousand hp dissipated as heat in small pump space can generate burst pressures in short times. ' Analysis should be on record.
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G ATTACHMENT 3 LIST OF ITEM FOR WHICH THE ACRS DISAGREES WITH THE PRIORITY RANKINGS PROPOSED BY THE NRC STAFF Generic Issue No:
97
Title:
PWR Reactor Cavity Uncontrolled Exposures Priority Ranking Proposed by the NRC Staff:
RESOLVED ACRS Comments:
This has been an issue for some time and it holds promise of causing a serious occupational injury and/or fatality. Therefore, the ACRS does not consider it resolved. Since the position of the incore detectors is indicated in the control room, why not simply feed a signal to a warning light at the entry door to the cavity? This would appear to be a relatively straight-forward resolution of the problem; it could be done at presumably low cost, and it would appear to be superior and a useful adjunct to the administrative " fixes" proposed heretofore,
,