ML20070H896

Forwards Test Rept on Emergency Spray Sys Testing Using Transco Therma-Wrap, in Response to NRC 821203 Request for Addl Info Re RCS Thermal Insulation.Transco Insulation Almost Identical to Owens-Corning Insulation

ML20070H896
Person / Time
Site:	Seabrook
Issue date:	12/08/1982
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO.
To:	Knighton G Office of Nuclear Reactor Regulation
Shared Package
ML20070H902	List: ML20070H896 ML20070H917 ML20070H935
References
SBN-409, NUDOCS 8212270279
Download: ML20070H896 (2)

Text

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IPUEBLIC SERVICE Companyof New Hampshre 1671 Worcester Road Framingham, Massachusetts 01701 (617) - 871- 8100 December 8,1982 SEN-409 T.F. G.l.l.10 B7.1.2 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing Re f erences: (a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNil Letter, dated November 30, 1982, "Second Revision to RAI 440.52 (Reactor System Branch)", J. DeVincentis to G. W. Knighton l

Subject:

Reactor Coolant System Tnermal Insulation

Dear Sir:

j Reference (b) provided general infonnation relative to the types of thermal insulation which will be utilized inside the Seabrook containment. In a telephone conversation with members of your Staff on December 3,1982, it was determined that more specific information was necerary in order for the Staf f to complete their review. The following provides chis information.

l There are two types of thermal insulation which will be utilized inside the Reactor Containment Building. They are: 1) metal reflective insulation manufactured by Transco, Incorporated, and 2) metal encapsulated fiberglass i insulation manufactured by either Owens-Corning Fiberglass Corporation or (

Tra nsc o , Incorporated . At the present time, the final vendor selection for I the fiberglass insulation has not been made. As described further, both manufacturers' products are similar and are equally acceptable from the standpoint of potential interaction with safety systems following a LOCA.

The metal reflective insulation is used on the reactor vessel. It is built of stainless steel panels and is attached using either buckle f asteners or self-taping screws.

The fiberglass insulation is used on all other primary system equipment or piping. It consists of a fiberglass insulating wool blanket encapsulated in a fiberglass cloth, reinforced with a fiberglass scrim and sewn with l fiberglass thread. The insulation blankets are held in place by a Velcro hook / loop fastening system. Stainless steel protective jacketing is held in place with a stainless steel hook / loop fastening system.

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United States Nuclear Regulato y Commission December 8, 1982

- Attention: Mr. George W. Knighton, Chief Page 2 Both types of insulation are designed to remain in place during and af ter a seismic event and not be adversely affected by postulated accident environmental conditions. Following a LOCA, the only insul.stion that will be dislodged is that in the vicinity of a high energy line break or in the direct ptth of the resultant jet. Any dislodged metallic insulation will settle out of the water flow in the bottom of containment. Approach flow veJocities are expected to be too low to transport heavy metallic assemblies. The fiberglass insu .ation assemblies have undergone substantial testing by both manufacturers i

being considered, to determine the behavior of the insulation under accident conditions and to ensure that containment sump operation is not impaired. The results of these tests demonstrate that this insulation is suitable for use inside containment and does not obstruct the flow through containment sump screens.

Owens-Corning Fiberglass submitted a topical report, OCF-1, to the NRC f or review in August, 1977. This report documented the testing performed on their encapsulated fiberglass insulation. The NRC has reviewed the report and found this insulation acceptable f or use in URR containment applications.

Transco, incorporated also manufacturers an encapsulated fiberglass blanket insulation of essentially the same design as Owens-Corning and virtually the same materials as Owens-Corning (see attached letter, dated May 4,1982, Transco, Incorporated to Public Service Company of New Hampshire). Additionally, Transco, Incorporated has perf ormed tests

- - similar to those described in the Owens-Corning Test Report, OCF-1, to verify the applicability of the OCF-1 test report to the Transco, Incorporated manufactured product (see attached Test Report, TTR-25N) .

From the above inf onnation, it can be seen that the Fiberglass Thermal Insulation Systems to be supplied by either vendor f or use in the Seabrock Containment Buildings will not interf ere with the operation of safeguards systems following a postulated loss of coolant accident.

Should any f urther inf ormatIon be required, please f eel f ree to contact u s.

Very truly yours, J. DeVincentis ~ //

Project Manager JDV/ PA/ ba Attachments cc: Atomic Safety and Licensing Board Service List

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