ML20236N007

Responds to Request for TS Interpretation on Containment Vent & Drain Valves at Braidwood

ML20236N007
Person / Time
Site:	Braidwood
Issue date:	04/07/1997
From:	Charemagne Grimes NRC (Affiliation Not Assigned)
To:	Capra R NRC (Affiliation Not Assigned)
Shared Package
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References
FOIA-98-155 TAC-M82930, NUDOCS 9807140359
Download: ML20236N007 (4)

Text

. a p2asig e  % UNITED STATES

,** s* y NUCLEAR RESULATORY COMMISSION l

& WASWNGTON, D.C. 300064m j

.,Q...,l April 7, 1997

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i MEMORANDUM TO: Robert A. Capra, Director, l Project Directorate III-2 Division of Reactor Projects III & IV, NRR FROM: Christopher I. Grimes, Chief Technical Specifications Branch i l Associate Director for Projects, NRR

SUBJECT:

REQUEST FOR TECHNICAL SPECIFICATION INTERPRETATION ON i CONTAINMENT VENT AND DRAIN VALVES AT BRAIDWOOD  ;

iI On October 4,1996, an operator identified two containment isolation valves on  !

each of the Braidwood units that were not being surveyed on the station's '

outside containment isolation valve surveillance. The valves missing from the  !

surveillance included a vent and a drain valve on a safety injection ter.t line  ;

local pressure indicator. The licensee entered the LCO for containment i isolation valves, applied Technical Specifications (TS) 4.0.3, verified that I the valves in question were closed and capped, hung administrative control i tags, and submitted a procedure change to include the valves on the surveillance.

The licensee initiated an investigation and concluded that these valves are not required to be surveyed closed to meet TS 4.6.1.1.a or 10 CFR 50 Appendix J criteria for this style of containment penetration. The licensee's bases for their position are that this penetration is capable of being closed by operable containment automatic isolation valve and that TS 4.6.1.1.a applies only to penetrations not capable of being closed by operable containment automatic isolation valves.

The Resident Inspectors were concerned that in the event that the inboard automatic containment isolation valve failed to isolate that the vent and '

l drain valves would be outboard barriers to a release of radioactive materials

! outside of containment. Considering the potential consequences of the vent and drain valves being left open, the inspectors believe that TS 4.6.I.1.a requirements apply to the instrument vent and drain valves. The Resident Inspectors requested NRR provide an interpretation of the TS 4.6.1.1.a to l resolve this issue.

The Technical Specifications Branch (TSB) has reviewed the information provided, and we find that the licensee's interpretation of TS 4.6.I.I.a is incorrect. In a memorandum from Christopher I. Grimes, Chief, Technical Specifications Branch to Herbert H. Berkow, Director Project Directorate II-2, "St. Lucie Containment Vessel Integrity (TIA 91-23)(TAC No. M82930) dated June 22, 1992, TSB stated that "The staff considers any valve associated with a containment penetration no matter how small to be a CIV [ containment isolation CONTACT: R. J. Giardina, TSB/NRR 415-3152 9907140359 980624 9 PDR FOIA UNNERST98-155 PDR .

4 ,*

i' R. Capra April 7, 1997 l

valve) . Therefore, vent, drain, and test valves are considered CIVs and the requirements of TS 3.6.1.1 apply to them." In addition 10 CFR 50, Appendix A, l General Design Criterion (GDC) 55, 56,- and 57 describe the various containment l penetration isolation designs which are acceptable to the staff. GDC 55 and l 56 list four types of isolation systems: 1) Both valves locked closed; 2)

Automatic isolation valve inside containment and a locked closed valve outside containment; 3) The reverse of 2; and 4) Both valves are automatic isolation valves. GDC 57 deals with a closed system which requires automatic, locked closed or remote manual valve outside containment. The basis for the GDC i designs is that a single failure will not prevent or degrade containment integrity (the closed system in GDC 57 acts as one containment isolation l barrier).

With the above taken into consideration the interpretation of TS 4.6.1.1.a becomes fairly obvious. It is clear the wording of TS 4.6.1.1.a. particularly

! from the "*" footnote, requires that all manual valves, blind flange, or deactivated automatic valves, serving as an isolation barrier, are to be verified as being closed regardless of whether the other valve in the penetration (if any) is an automatic valve or not. In this case, the manual vent and drain valves serve as such an isolation barrier.

The improved Standard Technical Specifications (STS) (NUREG-1431 for Westinghouse plants) reinforce this interpretation. The Cases for the Containment Isolation Valve TS state in the Background section "The containment isolation valves form part of the containment pressure boundary and provide a means for fluid penetrations not serving accident consequence limiting systems to be provided with two isolation barriers that are closed on a containment isolation signal. These isolation devices are either passive or active (automatic)." Additionally, the Bases for the containment isolation valve surveillance (SR 3.6.3.3) state "This SR does not require any testing or valve manipulation. Rather, it involves verification, through a system walkdown, that 'those containment isolation valves outside containment and capable of being mispositioned are in the correction position."

Braidwood's interpretation of TS 4.6.1.1.a apparently arises from the definition of containment integrity in the definition section of the Braidwood TS. The same definition in the improved STS has been relocated to the Bases for containment. The definition states that CONTAINMENT INTEGRITY l.7 CONTAINMENT INTEGRITY shall exist when:

a. All penetrations required to be closed during accident conditions are either:

! 1) Capable of being closed by an OPERABLE containment automatic isolation valve system, or

2) Closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed positions, except i as provided in Table 3.6-1 of Specifications 3.6.3....

l l

1

1 ,~

e* R. Capra April 7, 1997 Definition 1.7.a.1) could be interpreted to apply to all those penetrations which have at least one automatic containment isolation valve. As long as a penetration had one automatic valve, the other valves forming the containment boundary whether they are manual valves, blind flanges, or deactivated automatic valves would not have to be verified closed. TSB acknowledges that the definition could be read in such a manner. However, such a reading is inconsistent with the intent of the TS and the GDCs. TSB believes the better reading of the definition is that each penetration is required to be capable of being closed by automatic containment isolation valves, closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed position or an approved combination of the above that provides the two barrier isolation. In turn, all manual valves, blind flanges or deactivated automatic valves secured in their position must be surveilled in accordance with TS 4.6.1.1.a.

Given that the containment integrity definition might not clearly provide the staff's intent, TSB along with Containment Systems Branch will reevaluate the containment integrity definition and propose appropriate changes to the improved sis which the licensee can consider adopting to avoid future questions.

Docket Nos. 50-456/457 cc: J. Roe ,

G. Halahan C. Berlinger 1

I i

• . R. Capra April 7, 1997 Definition 1.7.a.1) could be interpreted to apply to all those penetrations which have at least one automatic containment isolation valve. As long as a penetration had one automatic valve,'the other valves, forming the containment boundary whether they are manual valves, blind flanges, or deactivated automatic valves would not have to be verified closed. TSB acknowledges that the definition could be read in such a manner. However, such a reading is inconsistent with the intent of the TS and the GDCs. TSB believes the better reading of the definition is that each penetration is required to be capable of being closed by automatic containment isolation valves, closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed position or an approved combination of the above that provides the two barrier isolation. In turn, all manual valves, blind flanges or deactivated automatic valves secured in their position must be surveilled in accordance with TS 4.6.1.1.a.

Given that the containment integrity definition might not clearly provide the staff's intent, TSB along with Containment Systems Branch will reevaluate the containment integrity definition and propose appropriate changes to the improved STS which the licensee can consider adopting to avoid future questions.

Docket Nos. 50-456/457 cc: J. Roe G. Holahan C. Berlinger D11TRIMIION:

FILE CENTER TSB R/F CIGrimes JGLuehman RJGiardina

\ TSB Staff I VBackground Books DOCUMENT NAME: G:\RJG\ BRAID.MEM *see previous concurrences 0FFICE TSB/ADPR/NRR (A)SC:TSB:ADPR:NRR C:SCSB:NRR C:TSB:ADPR:NRR NAME RJGiardina* JGLuehman* CBerlinger* CIGrimesh/hr DATE 12/16/96 12/16/96 . 03/18/96 Ok't/g1M OFFICIAL MtCORD COPY j

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