ML20056A731
| ML20056A731 | |
| Person / Time | |
|---|---|
| Issue date: | 08/06/1990 |
| From: | Thadani A Office of Nuclear Reactor Regulation |
| To: | Langley J GULF STATES UTILITIES CO. |
| Shared Package | |
| ML20056A732 | List: |
| References | |
| NUDOCS 9008090114 | |
| Download: ML20056A731 (3) | |
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.. c i,1 August 6, 1990 k
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~ Mr. J. R. Langley
. Project Manager, Mark III Containment
_HydrogenControlOwnersGroup(HC0G) c/o Gulf States Utilities forth Access Road at Highway 61 St. Francisv111e, LA 70775
-Deat Mr. lsngley:.
SUCdECT: ACCEPTANCE FOR REFERENCING 0F' LICENSING TOPICAL REPORT TITLED,
" GENERIC HYDR 0 GEN CONTROL INFORMATION FOR BWR-6 MARK III CONTAINMENTS", HGN-112-NP We have completed our review of the subject topical report submitted by your letter dated February 23, 1987.
We find the report acceptable for referencing in licensee analyses of-hydrogen control systems for BWR Mark III containments under the limitations-delineated in the report and its references and the associated NRC evaluation, which is enclosed. The evaluation defines the basis for acceptance of the report.
'Furthermore, each licensee should provide a plant-specific analysis and an.
assessment of the need for an independent power supply for the hydrogen ignition system. The plant-specific analysis may use test dati described in the topical report to confirm that the equipment necessary to establish and
. maintain safe shutdown and to maintain containment integrity wi'l be capable of performing their functions during and after exposure to the environmental conditions created'by the hydrogen in all credible severe accidett scenarios.
Recent risk studies reported in'NUREG-1150 have shown that the overall core melt frequency for one Mark III plant (the Grand Gulf Nuclear Station) is very low, i.e.,1E-6/ year. _However, a potential vulnerabil_ity for Mark-III plants involves. station blackout (SB0), during which the igniters would be inoperable; and this. condition appears to dominate the residual risk from severe accident in the Mark III plants. Under.SB0 conditions, a detonable mixture of hydrogen could develop which could be ignited upon restoration of power.resulting in loss of containment integrity. On the basis of a separate evaluation of this possibility in the context of the NRC staff Containment-Performance Improvement (CPI) program, the staff has recommended that the-vulnerability to interruption of power to the hydrogen igniters be evaluated further on a plant-specific basis as part of the Individual Plant Examinations (IPEs) of the Mark III plants. The staff has requested that.
the licensees consider this issue as part of the IPE in Generic Letter 88-20, Supplement 3.
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l Mr. J. R. Lingley - August 6, 1990 We do-not intend to repeat our review of the matters described in the report and found acceptable when the report is referenced in licensee requests for a) proval of final analyses of the hydrogen control system, except to ensure-t1at the material presented is applicable to the specific plant invohed.
Our acceptance applies only'to the matters described in the report and its
-references.
In'accordance with procedures established in NL' REG-0390, we request that HC0G submit to the NRC accepted versions of this report within three months of recei)t of this letter. The accepted versions should incorporate.this letter and tie enclosed-evaluation between the title page and the abstract. The accepted versions should also_ incorporate as appendices those references'used
-as,a basis for the staff's evaluation. The accepted version should include an
-A (designating. accepted) following the report identification number.
Your submittal should include an application for withholding the proprietary information accompanied by an affidavit meeting the requirements of 10 CFR 2.790(b). This final report submittal should also include a non-proprietary version of the proprietary reports referenced and incorporated in the approved topical report and intended to be employed as a part of a licensee application.
Should our criteria or regulations change such that our conclusions as to the acceptability of the report are invalidated, HC0G and/or the-licensees
-referencing the topical report will be expected to revise and resubmit their respective = documentation, or submit justification for the continued effective applicability of the topical report without revision of their respective documentation.
Sincerely, r.
MGINAl. SIGNED BY A. C.THADANI Ashok C. Thadani, Director Division of Systems Technology Office of Nuclear Reactor Regulation DISTRIBUTION TMurley/FMiraglia I(( MIN 13.@
WRussell-NRC PDR CSmyre (8800175)
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Mr.:J._R. Langley In accordance with procedures established in NUREG-0390, we request that HC0G submit-to the NRC accepted versions of this report within-three months of receipt of this letter. The accepted versions should incorporate this letter and the enclosed evaluation between the title page and the abstract.
The
-accepted versions should also incorporate as appendices those references used as a basis'for the staff's evaluation.
The accepted version should include an
-A (designating accepted) following the report identification number.
Your submittal-should~ include an' application for withholtiing the proprietary information4 accompanied by an affidavit meeting the requirements of 10 CFR 2.790(b). This final report submittal should also include a non-proprietary version of the' proprietary reports referenced and incorporated therein. This final' report submittal should also include a non-proprietary version of the proprietary reports referenced and incorporated in the' approved topical report s
and intended to be employed as a part of a licensee application.
Should our criteria or egulatio1s change such that our conclusions as to the acceptability of the eport ere invalidated, HC0G and/or the licensees referencing the topical regort will be expected to revise and resubmit their respective documentation._oi\\ submit justification for the continued effective applicability-of the topical ' report without revision of their respective documentation.
Sincerely, Asho C. Thadani, Assistant Director for ystems Divisio' of. Systems Technology Office o Nuclear Reactor Regulation b
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