Information Notice 1992-52, Barriers and Seals Between Mild and Harsh Environments

Barriers and Seals Between Mild and Harsh Environments

ML031200130
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Crane
Issue date:	07/15/1992
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-92-052, NUDOCS 9207090264
Download: ML031200130 (3)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555

July 15, 1992 NRC INFORMATION NOTICE 92-52:

BARRIERS AND SEALS BETWEEN MILD

AND HARSH ENVIRONMENTS

-

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to alert addressees to problems that could result from missing or

deteriorated barriers or seals that protect equipment designed to operate in a

mild environment from areas that could have a harsh environment following a

design basis accident (DBA). It is expected that recipients will review the

information for applicability to their-facilities and consider actions, as

appropriate, to avoid similar problems. However, suggestions contained in

this information notice are not NRC requirements; therefore, no specific

action or written response is required.

Description of Circumstances

On April 1, 1992, with the Millstone Nuclear Power Station, Unit 1, in cold

shutdown, the Northeast Nuclear Energy Company (the licensee) performed a

walkdown inspection of the environmental qualification barriers in the

switchgear area.

The licensee found a number of postulated steam paths into

the switchgear area, including gaps between floor hatch covers and the

surrounding floors, openings around doors where gasket material was missing, and miscellaneous small gaps and openings. The licensee had previously

performed evaluations for its environmental qualification (EQ) program hut did

not adequately document determinations of the acceptability of barriers or

unsealed openings. The licensee's EQ program also did not establish

procedures to periodically check and replace, as necessary, some of the

gaskets and seals used in the plant to protect equipment from a harsh

environment.

Discussion

In Section 50.49 of Title 10 of the Code of Federal Regulations, the NRC

established requirements for the environmental qualification of electrical

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IN 92-52 July 15, 1992 equipment important to safety.

Equipment that operates in a "mild"

environment was not included within the scope of the regulation; inherent is

the presumption that "mild" environments do not change into "harsh"

environments. The circumstances described above indicate that some licensees

may not have maintenance procedures to ensure the integrity of seals or

barriers between "harsh" and "mild" environment areas.

If safety-related

equipment intended for "mild" environments were operated at more demanding

conditions, it could cause safety concerns.

This information notice requires no specific action or written response.

If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

rles E. Rossi, irector

Division of Operational Events Assessment

-

Office of Nuclear Reactor Regulation

Technical contacts:

H. Walker, NRR

(301) 504-2827

J. Carter, NRR

(301) 504-1153 Attachment:

List of Recently Issued NRC Information Notices

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Attachment

IN 92-52

July 15, 1992 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information

Date of

Notice No.

Subject

Issuance

Issued to

92-51

Misapplication and

Inadequate Testing of

Molded-Case Circuit

Breakers

07/09/92

All holders of OLs or CPs

for nuclear power reactors.

92-50

92-49

Cracking of Valves in

the Condensate Return

Lines of A BWR Emer- gency Condenser System

Recent Loss or Severe

Degradation of Service

Water Systems

07/02/92

07/02/92 All holders

for BWRs.

All holders

for nuclear

of OLs or CPs

of OLs or CPs

power reactors.

92-48 t7_

7

92-46

Intent

ional Bypassing

of Automatic Actuation

of Plant Protective

Features

Thermo-Lag Fire Barrier

Material Special Review

Team Final Report Findings,

Current Fire Endurance

Tests, and Ampacity Cal- culation Errors

07/02/92

06/29/92

06/23/92

All holders of OLs or CPs

for nuclear power reactors.

All

for

holders of OLs or CPs

nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

92-45

Incorrect Relay Used in

Emergency Diesel Generator

Output Breaker Control

Circuitry

06/22/92 All holders

for nuclear

of OLs or CPs

power reactors.

92-44

92-43 Problems with Westing- house DS-206 and DSL-206

Type Circuit Breakers

Defective Molded Phen- olic Armature Carriers

Found on Elmwood Con- tactors

06/18/92

06/09/92

All holders of OLs or CPs

for nuclear power reactors.

All holders of OLs or CPs

for nuclear power reactors.

OL = Operating License

CP = Construction Permit