ML18030A050

Interim Deficiency Rept Re Failure of Design to Provide Control Room Habitability,Initially Reported on 810420.Study Is Underway to Determine Mods Required to Correct Deficiency.Addl Info Will Be Provided by 810801

ML18030A050
Person / Time
Site:	Susquehanna
Issue date:	06/05/1981
From:	Curtis N PENNSYLVANIA POWER & LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, PLA-830, NUDOCS 8106090585
Download: ML18030A050 (6)

Text

i 1 REGULATO INFORMATION DISTRIBUTION EM (RIOS)

ACCESSION NBR;810609058S DOC ~ DATE: 81/06/05 NOTARIZED: NO DOCKET FACIL:50 387 Susquehanna Steam Electric Station~ Unit 1~ Pennsy1va 0 038:

BYNAME 50 388 Susquehanna Steam Electric Station< Unit 2i pennsy1v 05000 8 AUTH AUTHOR AFF ILIATIOII CURTIS' ~ W~ Pennsylvania Power IL Light Co<

REC IP RAME RECIPIENT AFFILIATION GRIERt B H

~ ~ Region li Philadelphiai Office of the Director (81/03/01)

SUBJECT:

Interim deficiency rept re failure of design to provide control room haoitaoilityiinitially reported on 8104?O,Study is underway to determine mods required to correct EIeficiency.Addi info will be provided by 810801, DISTRISUTIOH CODE: SOISS COPIfS PECEIVED!LTH ~ ENCL g Construction Deficiency Report (iOCFRSO<SSE)

SIZE'ITLE; NOTES!Send IIIE 3 copies FSAR lL all amends,i cy:BNR LRG PM(L<RIB) 05000387 Send IKE 3 copies FSAR 8 all amends,i cy.'BRR LRG PM(CRIB) 05000388 RECIPIENT COPIES RECIPIENT COPIES IO CODE/NAME, I .TTR ENCL ID CODE/NAME LTTR ENCL ACTION: A/0 LICENSNG 04 I.IC BR 42 BC 05 LIC BR 42 I.A 06 STARKsR ~ 07 INTERNAL: ASLRP/J ~ HARD 0/OIR HUM FAC15 EOO tt, STAFF 19 EQUIP QUAL BR11 HYD/GEO BR 2?. I It,E 09 IE/EES LIC QUAL BR 12 MPA 20 NRC PD 02 OELD 21 EY 13 QA BR 14 REG F IJ 01 STANOROS OEV 21 EXTERNALs ACRS 16 ie LPOR 03 NSIC 08 1 TOTAL NUMBER OF COPIES REQUIRED; I TTR ~ ENCL

TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr (215) 770 5151 NORMAN W. CURTIS Vice President. Engineering & Construction-Nucieer 770 5381 June 5, 1981 Mr. Boyce H. Grier Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION INTERIM REPORT OF A POTENTIALLY REPORTABLE DEFICIENCY INVOLVING CONTROL ROOM HABITABILITY ERs 100450/100508 FILE 821-10 PLA-830

Dear Mr. Grier:

This letter serves to provide the Commission with an interim report of a potentially reportable deficiency regarding tne failure of SSES design, as approved and released for construction, to provide control room/habitability as described in the Susquehanna FSAR. The condition was originally report'ed by telephone to NRC Region I Reactor Inspector, Mr. L. Narrow, by Mr. A. R. Sabol of PPEL on April 20, 1981. Mr. Narrow was advised that the condition was considered potentially reportable under the provisions of 10 CFR 50.55(e) .

PPGL is currently investigating the condition and a final determination on the significance of the item will be made based upon its impact on control room habitability.

The Susquehanna FSAR provides for a dual pressure" differential envelope concept to ensure habitability inside the control room and the control structure. This dual envelope concept requires that a positive pressure differential be maintained both in the control structure air. space relative to the outside atmosphere .in the control room air space relative to the remainder of the control structure and the leakage from the control structure envelope into control room envelope be minimal.

As designed, the control room HVAC units are located outside the control zoom envelope and within the secondary control structure envelope. Because of the bolted construction of these HVAC units and because their return duct system may be subject to a negative pressure during operation, it is suspected that the integrity of the boundary between the control structure and control room envelopes may be compromised.

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> <8090 PENNSYLVANIA POWER & LIGHT COMPANY ih

Mr. Boyce H. Grier June 5, 1981 The analysis for control room habitability in the Susquehanna FSAR assumes a maximum leakage rate of 10 cfm of unfiltered air from the secondary envelope to the control room. Due to the design of the control contro'tructure room HVAC system as discussed above, it is suspected that a higher leakage rate will occur which could adversely affect habitability of the control room during a design basis accident. Thus, the condition is considered potentially reportable under 10 CFR 50.55(e) .

PP&L will be is studying the described condition and wil'etermine what modificat'ons, required to correct any inconsistencies between current design and if any, FSAR requirements.

We expect to provide additional information on this condition in a subsequent report prior to August 1, 1981.

Very truly yours, N. W. Curtis Vice President-Engineering a Construction-Nuclear FLW:sab cc: Mr. Victor Stello (15)

Director-Office of Inspection 6 Enforcement

~

U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. McDonald, Director (1)

Office of Management Information 6 Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Gary Rhoads U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655

A. R. Sabol N-4 SUSQUEHA.'PA STEAM ELECTRIC STATION REPORTABILITY TO NRC REGARDING IN THE DESIGN OF 'HANGES CONTROL ROOM HABITABILITYSYSTEMS ERs'- 100450/100508 FILES 821-10 840-4 PLI-'1'3758' --' - - . '160

Reference:

PLI 13455 Dated 5/20/81 Above referenced PLI provided a interim report regarding potential repoxtaoility, under 10 CFR 50.55e,'of the design changes in the control zoom habitability system. Background information zegarding the deficiencies which caused to the design changes is pxovided in the referenced PLI. Following paragraphs pxovide the final evaluation on this subject:

Based on latest NRC regulations, a review of SSES control roo habitability z,..C-system was performed by Bechtel including zecalculation o control Technical Support Center (TSC) and Operations Suoport Center (OSC) sation doses. During the review, of outside air assumed f'r it was found that 100 cfm unfiltered infiltration the control stx'ucture is high and this can be re-duced to 10 cfm per SRP 6.4.Through reanalysis using 10 cfm as stated above, it was determined that by maintaining a single envelope of control structure pressurized to +1/8" wg,the habitability inside the control structure including control room, the TSC and the OSC can be provided in accordance with SRP 6.4 and thus meeting zequirements of GDC 19.

In the revised design, cross flow between the control room and the control structure has no significance since both are in the same envelope. This leads us to believe that if the deficiency as stated in reference 1, were it to have remained safety of operations uncorrected, it would not have affected advezsely the of the Nucleax power plant, at any time during the life of the plant. In view of this NPE believes this deficiency to be not report-able under 10 CFR 50.55 (e) ~

Proposed Corzective Action:

FSAR sections for control oom habitability systems will be x'evised to incorporate single envelope concept and the assumption of 10 cfm for un-filtered infiltration of outside air.

We believe this completes NPE response to PLI 13338 and no further action is required by NPE.

Thank you, Ae M- Male Assistant Manager>>Nuclear Plant Engineering SDP/cah tENNSYLYANIA tOWER L LIGHT COPAtANY

t RESPONSE REQUIRED: No Copies to: J. R. Calhoun TV-16 S. H. Cantone N-4 H. R. Clarke N-4 T. M. Crimmins, Jr. N-4 N. W. Curtis N-4 S; L. Denson SSES

- R. H. Featenby SSES E. W. Figard SSES E. J. Gorski SSES J. D. Green SSES W. H. Gulliver N-4 H. W. Keiser SSES B. D. Kenyon N-4 P. H. Henrikson N-4 R. J. Jensen N-4 C. I. McVicker N-4 h,. M. Male N-4 W. J. Rhoades N-4 S. D. Pai N-4 R. J. Shovlin N-4 Letter File N-3 SPSE Pile N-3 Date Pile N-4

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