ML17139B418

Safety Evaluation Supporting Amend 12 to License NPF-14

ML17139B418
Person / Time
Site:	Susquehanna
Issue date:	03/09/1983
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML17139B417	List: ML17139B416 ML17139B418 ML17139B419
References
NUDOCS 8303180195
Download: ML17139B418 (5)

Text

SAFETY - EVAtUATION AMEND

. 'l 2 14 SUS()UEH

- '; UNIT:1 C

E Introduction In letters dated August 25, 1982 and September 14, 1982, the licensee identified the following as the Containment Vent and Purge System Valves.

For clarification, these valves are grouped by line sizes:

Valves-in. lines-no.greater. than-2.inches. in-diameter:

HV-15705, HV-15711, SV-15736A, SV-15737, SV-15767, and SV-15776A Valves in-6 inch-lines:

HV-15721 Valves-in.18 inch. lines:

HV-15703, HV-15704, HV-15724, and HV-15725 Val ves. in. 24-.inch-l ines:

HV-15713, HV-15714, HV-15722, and HV-15723 The licensee, in the September 14, 1982 letter, as amended by the licensee letter dated October 29, 1982 (PLA-1372), propose'd an amendment to License Condition 2.C.(5) to the operating license for Susquehanna Steam Electric Station, Unit 1 to:

a) permit the operation of purge valves HV-15704, HV-15714, HV-15721, HV-15722, HV-15723, HV-15724, and HV-15725 after these valves have been blocked so as not to permit opening by more than 50

degrees, b) clarify the blocking of valves to a maximum opening or maintenance of valves in the closed position as only required for operational conditions other than cold shutdown or refueling, and c) provide, prior to startup following the first refueling outage, purge valve qualification documentation which demonstrates the purge supply and exhaust isolation valves are qualified to close from the full open position against peak LOCA pressure.

OFFtCE/

~ ~ ~ ~ ~\\ ~ ~ ~ 0 ~ ~ 0

~ 0

~

~ ~ ~

~ 0 ~ ~ 0 ~ ~ ~ 0 ~I~ ~ ~ ~ ~

~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~

~ ~

0 ~ ~ ~ ~ ~ let t~ko M ~

~

~ ~ ~ 0 ~ ~ ~ ~ 0 ~ ~ ~ ~ ~ ~

~ ~ ~ ~ e ~ ~ ~ eoeI ~ ~ ~ ~ ~ ~ ~ ~ O ~ I~

03180195 83030

~ '83 00387

~",:PDR.ADOGK 0500 P

~ ~ ~ 0 ~ ~ ~ 0 ~ ~ ~ 0 ~ ~ ~ ~ ~I

~ ~

~

RECORp CO US~~: 1SS)~~VASSS

l 0

Safety-Eval uati on For the valves listed above in lines no greater than.2.inches in diameter, the licensee has stated that these valves have been qualified.

Since these valves are in lines less than 3 inches in diameter, the staff accepts the licensee' statement of qualification as being consistent with NRC staff requirements as stated in NUREG-0737, Action Item II.E.4.2.

For the 6-inch valve, the staff previously accepted the qualification of this valve as stated in Supplement No. 4 to the Susquehanna Safety Evaluation Report.

C'he staff had concerns regarding the qualification of the valves in the 18-inch and 24-inch lines.

ASME or American Institute of Steel Construction (AISC) allowable levels should be@used for a shear analysis on valve internals and parts that are required for the valve to perform its safety function.

In Supplement Ho. 4 to the Susquehanna Safety Evaluation Report, the licensee was requested to use a conservative allowable shear stress of 0.4Sy + 12,000 psi (AISC).

When the valves are analyzed under full open conditions, the valve top pins for the 18-inch and 24-inch valves were the only components of the valves determined to have stress levels that would exceed conservative allowable levels.

In a letter dated October 29, 1982 (PLA-1371), the licensee provided additional containment vent and purge valve qualification information which provided disc pin stresses for the 18-in.

and 24-in. containment purge valves calculated at various blocking angles.

The actual top pin stresses calculated with the valves blocked to 50 degrees is 6208 psi for the 18-in. valves and 7160 psi for the 24-in. valves.

When blocked to 50 degrees, therefore, the 18-in.

and 24-in.

valve top pin stress levels were below conservative allowable levels.

Based on th'e above, all 18-inch, and 24-inch purge and vent valves are accept-able for operation provided they are blocked to a maximum opening of 50 degrees

- or less.

All purge and vent valves 2 inches and smaller, and the 6-inch valve are operable without blocking based on being qualified valves.

The staff proposed alternate language for revising License Condition 2.C.(5) which was discussed with and agreed to by the licensee.

The alternate lan-guage provides the requested clarification regarding cold shutdown and refueling operations, requires that valves restricted to operation at maximum openings of 50 degrees or less (18-inch and 24-inch valves) be kept closed until physically blocked to 50 degrees or less, and allows the maximum 50 degree opening restriction to be removed based upon approval by the HRC,.

staff of appropriate qualification documentation.

OFFICE/

SURNAME/

DATE 5 NRC FORM 318 (10-80) NRCM 0240

~ ~

~ ~ ~ ~ ~ 0 ~ 0 ~

~ 0 ~ 0 ~I~

~ ~ ~ 0 ~ ~ ~ ~

~ ~ 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

OFFICIAL RECORD COPY

~ 0 ~

~

\\ ~ ~ ~ ~ ~ ~ ~ ~ ~

~

U80PO: 1881~8-960

On the basis of this evaluation, License Condition 2.C.(5) is changed to read:

(5) gualification-of-Purge-Valves Whenever the operational condition is other than cold shutdown or refueling, PPSL shall maintain each containment purge and vent isolation valve greater than 2-in. nominal diameter in one of the following conditions:

a)

Closed and electrically prohibited from opening, b)

Blocked so as not to permit opening by more than 50 degrees, or c)

Operated to permit opening by more than 50 degrees after demonstrating that the valves are qualified to close from the full open position against peak LOCA pressure, and are also qualified per the criteria of Branch Technical Position CSB 6-4.

Purge valve qualification documentation must be approved by the NRC prior to operating valves in this mode.

Environmental-Consideration We have determined that this amendment does not authorize a change in effluent types or total amount nor an increase in power level and will not result in any significant environmental impact.

Having made this determination, we have further concluded that this amendment involves action which is insignificant from the standpoint of environmental

impact, and, pursuant to 10 CFR Section 51.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.

Conclusion We have concluded, based on the considerations discussed above that:

(1) because the amendment does not involve 'a significant increase in the probability or consequences of accidents previously considered, does not create the possibility of an accident of a type different from any evaluated previously, and does not involve a significant decrease in a safety margin, the amendment does not involve a signifcant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed

manner, and (3) such activities will be conducted in compliance witH the Commission's regulations and the issuance of this amendment will not be inimcal to the common defense and security or to the health and safety of the public.

Dated:

OFFICEI SURNAMEP DATE 5 RL'LAN,."1...

RPerch:pt

..N.'J,

.I VN o c

NRC FORM 318 f10-80) NRCM 0240 OFFICIAL RECORD COPY USOPO: 1981 335-9GO

O.

C<e: