ML20056D840

Forwards Corrected Submittal of Relief Request RI-29

ML20056D840
Person / Time
Site:	LaSalle
Issue date:	08/13/1993
From:	Piet P COMMONWEALTH EDISON CO.
To:	Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
NUDOCS 9308180122
Download: ML20056D840 (3)

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4 August 13,1993 Dr. Thomas E. Murley Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 Attn: Document Control Desk

Subject:

LaSalle County Station Units 1 and 2 In-Service inspection Program Submittal of Relief Request RI-29 Docket Nos. 50-373 and 50-374

Reference:

(a) P. Piet letter to T. Murley, dated August 4,1993. ,

Dear Dr. Murley:

In Reference (a), Commonwealth Edison Company (CECO) transmitted relief requests numbered RI-24 RI-25, RI-26, RI-27 and RI-28 to address various sections of ASME Section XI,1980 Edition, Winter 1980 addenda. However, CECO inadvertently mistitled Relief Request RI-29 as RI-24. The appropriate numbering for this Relief Request, which describes alternate testing of Class 3 systems in lieu of ten- ,

year hydrostatic pressure testing, is RI-29. There are no other changes to this -  !

proposed Relief Request other than the aforementioned administrative change. A }

corrected copy is provided as an attachment to this letter. l CECO apologizes for any inconvenience that this issue may have caused your .

Staff. If there are any questions, please contact this office.

Respectfully,  !

CM

' Peter L. Piel Nuclear Licensing Administrator

Attachment:

Relief Request RI-29 for LaSalle County Station  ;

cc: J.B. Martin, Regional Administrator-Rill- ,

J.L. Kennedy, Project Manager-NRR D. Hills, Senior Resident inspector-LSCS  ;

Office of Nuclear Safety-IDNS j

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REUEF REQUEST NUNBER RI-29 ,

(Page 1 of 2)

CONPONENT IDENTIFICATION Code Class: 3

Reference:

Table IWD-2500-1, and IWD-5223(a)

Exanination Category: D-A, D-B, and D-C '

Item numbers: D1.10, D2.10, and 03.10

Description:

Altemate Testing of Class 3 Systems in Lieu of Ten-Year Hydrostatic Pressure Testing Component Numbers: Various -

CODE REQUIREAERE ASME Section XI, Table IWD-2500-1 requires Class 3 pressure retaining components '

be exposed to VT-2 examinations while the systems are subjected to elevated pressure hydrostatic tests, at or near the end of each inspection interval.

ASME Section XI, IWD-5223(a) states that the system hydrostatic pressure shall be at least 1.10 times the system pressure Psv for systems with a design temperature of 200 F or less. It also states that the system pressure Psv shall be the lowest pressure setting among the number of safety or relief valves provided for over-pressure protection within the boundary to be tested (or, design pressure Pd if over-pressure protection is not provided).

1 EMSIS FOR REUEE Elevated pressure tests are difficult to perform and often represent a true hardship. -

Some of the difficulties associated with elevated pressure testing include the following: ;

- Hydrostatic testing often requires complicated or abnormal valve line-ups in i order to properly fill, vent and isolate the components requiring testing.

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- Relief valves with set-points lower than the hydrostatic test pressure must be gagged or removed and have blind flanges installed. This process requires  ;

draining and refilling the system. -

- Valves that are not normally used for isolation (e.g., normally open pump discharge valves) are often required to provide pressure isolation for an elevated ,

pressure hydrostatic test. Thew valves frequently require time consuming seat i maintenance in order to allow for pressurization.  ;

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REUEF REQUEST NUNBER: RI-29 f (Page 2 of 2)

BASIS FOR REUEF (Continued)

- The radiation exposure required to perform a hydrostatic pressure test is high (in comparison to an operational pressure test) due to the large amount of tirne required to prepare the system for testing (i.e. installing relief valve gags, installing blind flanges, performing appropriate valve line-ups, etc). ,

The difficulties encountered in performing a hydrostatic pressure test prohibitive when weighed against the benefits. Industry experience shows that most through wall leakaga is detected during system operation as opposed to during elevated pressure tests such as the ten-year hyd.ostatic tests.

Uttle benefit is gained fmm the added challenge to the piping system provided by an elevated pressure hydrostatic test (when compared to an operational pressure test).

The piping stress experienced during a hydrostatic test does not include the significant stresses associated with the thermal growth and dynamic load:.1g ,

l associated with design basis events.

These arguments are supported by the adoption of Code Case N-498, "Altemate Rules for 10 Year Hydrostatic Pressure Testing for Class 1 and 2 Systems,Section XI,. '

Division 1". This relief request is a natural extension of that Code Case.  ;

Based on the above LaSalle County Station requests relief from the ASME Section XI requirements for performing the ten-year elevated pressure hydros +t tests on class 3 ,

systems.

PROPOSED ALTERNATE.EXAMNAllON A VT-2 examination will be performed during either a system functional test or during a system inservice test, in accordance with the requirernents of IWA-5213 (b) and (c) respectively, at or near the end of the inspection interval, prior to reacar startup.

APPUCABLE TINE PERIOD  ;

Relief is requested for the first ten-year interval of the System Pres sure Testing Program at LaSalle County Station Unit 1 and 2.

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