ML18114A738

Clarifies Causes for Hardware Mods Identified in Earlier Submittals of 790605,12 & 19 in Response to NRC 790621-22 Review of Pipe Stress Reanalysis

ML18114A738
Person / Time
Site:	Surry
Issue date:	06/25/1979
From:	Spencer W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton Office of Nuclear Reactor Regulation
References
511, NUDOCS 7906290327
Download: ML18114A738 (11)

Text

e VIRGINIA ELECTRIC.A.ND POWER COMPANY RIOHMOND,VIRGINXA 23ffl!GULATORV DOCKET,fll[ COPY June 25, 1979 Mr. Haro1d R. Denton, Director Office of Nuc1ear Reactor Regu1ation U.S. Nuc1ear Regu1atory Commission Washington, DC 20555

Dear Mr. Denton:

SUPPORT INFORMATION REANALYSIS OF PIPNG SYSTEMS SURRY POWER STATION UNIT 1 Seria1 No. 511 PSE&C/CMRjr:mac:wang Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37 Members of the Nuclear Regulatory Commission (NRC) staff conducted a review June 21 and 22, 1979 of the pipe stress reanalysis effort for Surry Power Station Unit 1.

As a result of that review, we wish to clarify the causes for hardware modifications identified in earlier submittals.

The NRC review has confirmed the categorization of hardware modifications in the manner described as fo1lows.

Of five pipe stress prob1ems identified as requiring modifications due to overstress conditions in the pipe, three are attributab1e to as-built conditions, one is due to seismic stress in a line not previous1y ana1yzed, and one is attributable to the seismic reana1ysis as required by the March 13 Show Cause Order.

Of three problems requiring modifications due to support loads exceeding original design al1owab1es, al1 three are attributab1e to as-bui1t conditions. Specific identification of these problems fo11ows.

Not all problems have been processed through Engineering Assurance as yet.

Modifications identified in the report submitted on June 5, 1979 (Vepco Serial No. 453):

1.

Problem 548A - Containment and Recirculation Spray A hori zonta 1 shock suppressor wi 11 be added to reduce pipe stress increases attributable to differences between the as-built configuration of the pipe and the original basis for design calculations.

2.

Problem 731A - Low Head Safety Injection A support brace wi 11 be added to reduce support 1 oads caused by a difference between the support design and the as-built condition of the support.

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VIRGINIA ELECTRIC AND POWER COMPANY TO Mr. Harold R. Denton, DireGtor

3.

Problem 7318 - low Head Safety Injection Same as Problem 731A.

4.

Problem 743 - low Head Safety Injection A vertical constraint will be modified to reduce pipe stresses attributable to the support being located in a position different from that used in the original analysis.

Modifications identified in submittal of June 12, 1979 (Vepco Serial No. 477):

5.

Problem 508 - Residual Heat Removal Several modifications to reduce pipe stresses and support loads are attributable to the seismic reanalysis required by the Order to Show Cause.

Modifications identified in submittal of June 19, 1979 (Vepco Serial No. 494):

6.

Problem 555 - Low Head Safety Injection A shock suppressor will be added to reduce support loads due to differences between the as-built conditions of the supports and the original design conditions.

7.

Problem 562 - Containment and Recirculation Spray Three supports will be modified to reduce pipe stresses attributable to differences between the as-built configuration of the pipe and the original design calculations.

8.

Problem 540 - Residual Heat Removal Three supports wi 11 be de 1 eted and one anchor added to reduce pipe stresses in a 2 inch 1 i ne which was not originally computer analyzed for seismic loads.

2

e VIRGINIA. ELECTRIC AND POWER COMPANY TO Mr. Harold R. Denton, Director The Order to Show Cause requires the reanalysis of piping systems for seismic loads using a computer code which does not combine loads algebraically, and any modificatt-0ns to the systems indicated by such reanalysis to be necessary.

In ocrr earlier letters it was assumed that, pursuant to this Order modifications, if any, would be caused by the seismic analysis.

As noted above, our subsequent submissions and discussions with the staff have shown that relatively few modifications are required as a result of changes in the seismic analysis, whereas, a larger number are required for other reasons not contemplated earlier and not covered by the Order to Show Cause.

At the same time, we have undertaken a major effort to respond to IE Bulletin 79-02. It is, therefore, necessary to clarify the intent of our earlier letters, particularly our letter of June 8, Serial No. 458, to the effect that base plate flexibility considerations will be incorporated in those supports for which the new loads, due to the seismic reanalysis, exceed the original design allowable loads and for any new supports required by the reanalysis effort. Supports which must be modified for other reasons, such as as-built conditions, will be evaluated for base plate flexibility under the IE Bulletin 79-02 program.

Confirming our earlier understanding with the staff, that for<~emergency loading conditions the effect of anchor movement need not be considered for the l.8Sh ch~ck, we shall henceforth not include seismic anchor movement stresses in the Design Basis Earthquake condition in the analysis of pipe supports and integral attachments.

Problem 630 was originally analyzed by applying the stress intensification factor (SIF) for an ASA 12 11 x 12 11 tee at the 6 11 45° lateral connections on the pressurizer relief valve manifold. This SIF was applied at that time by the analyst because no better data were available for these types of connections. At this time, we consider this approach to be over-conservative.

The reanalysis effort of Surry Unit 1 is using the stress intensification factor for a latrolet.

We consider the SIF for a latrolet to more closely represent the 45° rei~forced lateral connections.

The SIF for the latrolet, as derived by Bonney Forge based on experimental data, is contained in their

. May 1978 Bulletin No. 785, 11 Stress Intens ifi cation.. Factors for the Latro let.

11 It is our understanding that the staff now requires that prior to start-up, all pipe stress analyses must be complete, all analyses of pipe supports for SHOCK II problems inside the containment must be complete.

The hardware modifications associated with either of these must also be complete.

We believe this level of completion will be reached during the month of August. A closer date than that is not determinable at this time based on our past experiences with predicting completion dates.

For the SHOCK II problems outside containment,. all support loads will be tabulated and available for NRC review. A list of SHOCK II problems inside the containment is contained in the attached Table I.

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VIRGINIA ELECTRIC AND PowE:e COMPANY TO Mr. Harold R. Denton, Director Attachment III of our June 8, 1979 letter (Vepco Seri al No. 458-)

. identified a priority list and schedule for all problems for both pipe stress analysis and support analysis. June 30 was the last date shown for the completion of the pipe stress portion of the analysis.

We would propose a meeting for Tuesday, July 10, 1979 for the staff to review the results of all problems for which hardware modifications are required to meet allowable pipe stresses. This would include work done by Stone & Webster Engineering Corporation and Quadrex/NSC Corporation.

Attachment W. C. Spencer Vice President - Power Station Engineering and Construction Services 4

Serial No. 511

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TABLE I June 25, 1979 SHOCK II PROBLEMS INS IDE CONTAINME.a.'lT Problem Number System 555 Low Head Safety Injection 1555 Low Head Safety Injection 706A Low Head Safety Injection 707A Low Head Safety Injection 708 Low Head Safety Injection 1525A Containment & Recirculation Spray 525A Containment & Recirculation Spray 546/560 Containment & Recirculation Spray 546/5600 Containment & Recirculation Spray 546/5620 Containment & Recirculation Spray 548C Containment & Recirculation Spray 547 Containment & Recirculation Spray 548A Containment & Recirculation Spray 548B Containment & Recirculation Spray 544 Containment & Recirculation Spray 544A Containment & Recirculation Spray 544B Containment & Recirculation Spray 562 Containment & Recirculation Spray 323A Main Steam 322A Main Steam 334A Main Steam 323B Feed Water 322B Feed Water 334 Feed Water 417 Auxiliary Feed Water Page 1 of 2

Problem Number 636 630 540 508 465 603A 605A 605B 603B TABLE I (continued) e System Pressurizer S,pray & Relief Pressurizer Spray & Relief Residual Heat Removal Residual Heat Removal Service Water Component Cooling Component Cooling Component Cooling Component Cooling Page 2 of 2 Serial No. 511 June 25, 1979

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e UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.

20555 June 22, 1979 IE Circular No, 79-09 OCCURRENCES OF SPLIT OR PUNCTURED REGULATOR DIAPHRAGMS IN CERTAIN SELF-CONTAINED BREATHING APPARATUS Description of Circumstances:

The Nuclear Regulatory Commission (NRC) has been informed by mailgram (copy enclosed) from the National Institute of Occupational Safety and Health (NIOSH) of the high rate of regulator diaphragm failures in the Scott Air Pak II/IIA and Presur-Pak II/IIA self-contained breathing apparatus.

The failures, ranging from pin holes in the diaphragm to complete diaphragm rupture, have been identified in about 10 percent of the units by the NIOSH field survey, Tests of the Scott apparatus by NIOSH showed reduced respiratory protection in the Demand-Mode and a loss of service time (but no loss of protection) in the Pressure Demand-Mode.

Notice to Licensees:

Many major licensees use the types of Scott apparatus described above.

Users of the devices should take the following action:

1. Establish a program for examination of the described respiratory devices in accordance with the enclosed NIOSH mailgram; or

2.

Incorporate the provisions of the NIOSH mailgram into your current program for inspection of the described devices.

No written response to this Circular is required.

If you require additional information regarding this subject, please contact the individual specified in the enclosed mailgram.

Enclosure:

Mailgram

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GSA SWITCHING CTR.a.

P O bOX lUO W

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ROMNEY,wv 20757 1*05618bUli201Q 05/02/79 ICS ~A1213q 00~92 HLTN VA 05/02/79.

MR. JERRY CAPLXN USNRC WASHINGTON, DC 2055~

RESPIRA10R USERS WARNING J.c-,'!,

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WSHA THE NATIONAL lNSTITUTt FOk OCCUPATIONAL SAFETY AND HEALTH (NIUSH) WANTS TO ADVISE USf:.RS.. Of SCOTT AIR PAK ll/IIA AND PRESUR~~AK lI/lIA StLF*CONTAlNED BREATHING APPARATUS OF THE OCCURRtNCtS Or SPLIT OR PUNCTURED REGULATOR DIA~HRAGMS. NIOSH TESTS lNVt:STlGATlNG.. THE E.fFl:CT OF SUCH DEFECTS SHO..it.D REDUCED

..... :::-.... RI: S 1-' l R A l () R Y P R O T E C T 1 0 N UN - D t:. M A ND* MODE A P P A R A T US,

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--*-****s A Mc. T t. $ T S A L SO S HO I'! E D NO L OS S l N P R O T £ C T I ON, 8 UT A L OS S I N

........ SERvICE. T It-IE. 11/Hf:.N IN Tl1t. PRt.SSURE DE.MAND*MODE 1 NOTE: THE PRE:,suRt. DE.MAND UNIT IS NUT 'APPl'<OVED WHILE IN THE DEMAND MUDti l~t Ot~ANv MOO~ IS TO Bt UStU FOR DONNING PUkPOSES ONLY.

NlOSH ~tGAN THIS lNVESTlGAllON fULLOWlNG THt RtCENT DEATH OF TrlREE ~lHEFIGHTERS-~HO htRt ~EARING THIS TYPt OF RES~!RA10~, ALTH8UGH IT HAS NOT BEEN t5TA6L1SHEU THAT THE DEAlHS ~t~t DUE TU DAMAGED R~GULATOR DIAPHRAGMS.

A SAMPLlNb Or THt APPARATUS lN THt FIELD HAS SHO~N AT LEAST 10X OF lHt UNITS fXAMlNl.:.D HAVE ~UPTURtD OR PUNCTURED DIAPHRAGMS.

U~t~S ~HOULD EXAMlNt THtlk SCOTT APPARATUS FOR POSSIBLE OAMAGEO DIAPHRAGMS IN ACCORUANCt ~ITH MANUF~CTURt~'S INSTRUCTIONS. THt USEH SHUULD CHtCK THE DIAPHkAGH BtFORE EAC~ Ubt ~y CLOSING.BOTH THt MiIN LINE ANU ~yPASS VALVES

• A~D eLOwlNG THROUGH THE RtGULATUR OUTLET PO~T. lT SHOULD bE POSSlbLt TO MAINTAIN A SLIGHT POSITIVE PkESSU~t IN T~E RtGULATUR. THt USER.SHOULD CHtCK THt REGULATOR UlAPHRAGM AfltR tACH USE AND DUklNG MONlHLY INSPECTIONS 0~ TH~

COMPLElt APPAkATUS. IT IS NUT KNOWN IF FAILURt UCCUHS OURI~~

ASSc~oLY, STOKAGt, UR.USE Of.THt RESPIRATOR RtGULATOR.

!hEK£FU~£, tXTREME CAUSTlO~ MUST BE EMPLOYtD ~Ht.N USING

]Hl RtSPlijAlOM 1 lN tHtC~l~G THE OPERATION OF THt RtSPlRATOR, UStHS AHt ciuTIONED'NOT ro* BLOCK THE FLO~ of AI~ FROM THE RE.GULATUk

~~El~ THE ~yµA~S VALVE IS OPtN, BECAUSE SUBSTANTIAL JbST~UCTlD~ MAY kUPTUHE Ok DISLUDGt THE DIAPHNAGM. If THE JSt~ UcSERVt.S A L08SE 0~ DlSLODGlD REGULATOR COYER, THE COV~R

\\UST tH.,§~~~r;~ r.fJi£Rl~f~EPlt.t~1s~As~:~ Fi~¥.~~-~!.ED 81:.~Uwr:

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PAGI:. 2 e

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~ OF lHE RtGULATOR.

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Nl0SM HAS REQUESTED THE MA~UFACTURER STOP ALL SALES OF THE RESPIRATOR ~~NDING DETE~MlNATlON OF THE REASON FOR AND NECESSA~Y CUR~ECTivE ACTION TO PREVENT DIAPHRAGM FAILURE, FOR FURlHER l~CHNICAL INFORMATION CONTACTS MR, KlCHARD RONK,

NIOSH, 9~~ CHESTNUT RlD~E ROAD, MORGANTOWN, WV 26505.

PHONES (3-en 59g.. 7337.

3C'f ANTHONY ROB~INS, M.D.

DIRl:.CTOK, NlUSH RUCKVlLLE MD (A~S ~u~VrCZ o-26-01-036883) 21:19 tST MGMCUMP Ml:iM TO REPLY SY r.~;.ILGRAP/.. SEE REVERSE SIDE FOR \\','ESTER:~ u:;10:~*s ~C:.L - FF.EE p,..;c:;E r;L':.:=ERS

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IE Circular No. 79-09 June 22, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST TWELVE MONTHS Circular No.

78-10 11 78-12 78-13 78-14 78-15 78-16 78-17 78-18 Subject Control of Sealed Sources Used in Radiation Therapy Recirculation M-G Set Overspeed Stops HPCI Turbine Control Valve Lift Rod Bending Inoperability of Multiple Service Water Pumps HPCI Turbine Reversing Chamber Hold Down Bolting Checkvalves Fail to Close In Vertical Position Limitorque Valve Actuators Inadequate Guard Training/

Qualification and Falsified Training Records UL Fire Test Date of Issue 6/14/78 6/15/78 6/30/78 7 /10/78 7 /12/78 7 /20/78 7 /26/78 10/13/78 11/6/78 Enclosure Page 1 of 2 Issued To All Medical Licensees in Categories G and Gl All Holders of BWR OLs or CPs All Holders of BWR OLs or CPs for plants with HPCI Terry Turbine All Holders of Reactor OLs and CPs except for plants located in: AL, AK, CA, FL, GA, LA, MS, SC All Holders of BWR OLs or CPs for plants with a HPCI Terry Turbine excepting Duane Arnold and Monticello All Holders of Reactor OLs or CPs All Holders of Reactor OLs or CPs All Holders of and applicants for Reactor OLs All Holders of Reactor OLs or CPs

~

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IE Circular No. 79-09 June 22, 1979 e

LISTING OF IE CIRCULARS ISSUED IN LAST TWELVE MONTHS Circular No.

78-19 79-01 79-02 79-03 79-04 79-05 79-06 79-07 79-08 Subject Manual Override (Bypass) of Safety Actuation Signals Administration of Unauthorized Byproduct Material to Humans Failure of 120 Volt Vital AC Power Supplies Inadequate Guard Training-Qualification and Falsified Training Records Loose Locking Nut On Limitorque Valve Operators Moisture Leakage In Stranded Wire Conductors Failure to Use Syringe and Battle Shields in Nuclear Medicine Unexpected Speed Increase of Reactor Recirculation MG Set Resulted in Reactor Power Increase Attempted Extortion - Low Enriched Uranium Date of Issue 12/28/78 1/12/79 2/16/79 2/23/79 3/16/79 3/20/79 4/19/79 5/2/79 5/18/79 e

Enclosure Page 2 of 2 Issued to All Holders of CPs All Medical Licensees except Teletherapy Medical Licensees and each Radiopharmaceutical Suppliers All Holders of Reactor OLs and CPs All Holders of and applicants for Special Nuclear Material Licenses in Safeguards Group I All Holders of Reactor OLs or CPs All Holders of Reactor OLs or CPs All Holders of Medical Licensees except teletherapy licensees All Holders of BWR OL's or CP's All Fuel Facilities Licensed by NRC