ML18086A835

Forwards Addl Info Re long-term Operability of Containment Purge & pressure-vacuum Relief Valves,Per NRC 810618 Request. Seismic Vibration of (1)10 Inch,(1)20 Inch & (1) 36 Inch Butterfly Valves for Masoneilan Intl,Inc, Encl

ML18086A835
Person / Time
Site:	Salem
Issue date:	07/31/1981
From:	Mittl R Public Service Enterprise Group
To:	Miraglia F Office of Nuclear Reactor Regulation
Shared Package
ML18086A836	List: ML18086A835 ML18086A837 ML18086A838
References
NUDOCS 8108060082
Download: ML18086A835 (7)

Text

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OPS~G*

Public Service Electric and Gas Company 80 Park Plaza, T160 Newark, N.J. 07101 201/430-8217 Robert L. Mitt! July 31, 1981 General Manager - Licensing and Environment

• Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 t> ' ftf.[IV ED Attention: Mr. Frank J. Miraglia, Chief AUG 0 5 1981

• Licensing Branch 3 ~.ta~~,'

Division of Licensing Gentlemen:

CONTAINMENT PURGE AND PRESSURE-VACUUM RELIEF VALVES UNIT NO. 2 SALEM NUCLEAR GENERATING STATION DOCKET NO. 50-311 As requested by your June 18, 1981 letter, PSE&G hereby submits, in the enclosure to this letter, additional information relating to the long-term operability of the containment purge and pressure-vacuum relief valves.

Should you have any questions in this regard, do not hesitate to contact us.

Very truly yours, it#r CC: Mr. Leif Norrholm Senior Resident Inspector

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8108060082 810731 \

PDR ADOCK 05000311 P PDR The Energy Pec5ple

e e SALEM GENERATING STATlON NO. 2 UNIT CONTAINMENT PURGE AND PRESSURE-VACUUM RELIEF VALVES ADDITIONAL INFORMATION TO SUPPLEMENT NOV. 8, 1979 SUBMITTAL Ten (10) inch Pressure Relief Butterfly Valves

1. The peak containment pressure predicted for the DBA-LOCA is 43.2 psig.

l.a The maximum Tech. Spec. closure requirement for these valves is two (2) seconds.

l.b It is estimated that the valves will start to close in about one to two seconds after the incident at which time the con-tainment pressure is calculated to be 10 to 14 psig. The valves have a' closure time of two seconds or less, therefore, the valve should be fully closed in three to four seconds after the incident. At that time, the containment pressure is calculated to be 18 to 24 psig.

2. The seating torque requirement of 1390 in-lbs includes both bearing friction and seating resistance of the liner.

3. *The coefficient value of 76~2 in-lb. used to calculate dynamic

. psi ,

torque was.established by the manufacturer using extrapolation of test results.

The adequacy of this coefficient value was reviewed with regard to the installation configuration of the valve.

There are no elbows upstream of the valve inside the containment.

Therefore, there is no effect on the coefficient value.

There is an elbow immediately upstream of the valve outside the containment. The elbow is in the same plane as the piping downstream of the valve. The elbow immediately upstream of the butterfly valve will skew the turbulent pressure profile so that there is an increase in pressure along the outer wall and a decrease in pressure along the inner wall. Depending on the installation, the effect will be to either increase or decrease the torque to open the valve. The amount of increase or de-crease has not been quantified by the manufacturer. However, the manufacturer's experience has been that this effect is neglible and does not present a deleterious condition to valve operation.

4. The Bettis actuator used is equipped with a limit stop in the open position. The required torque loads will be imposed on.

the shaft by th~ pressure drop across the vane. If the required torque (tending ~o close the valve) exceeds the maximum output of the actuator, then the valve will begin to close. The maximum torque that can be seen is the actuator output. With a 47 psid,maximum torque on the shaft is the dynamic load (76.2 x 47). However, for the 60 psig case, the required torque exceeds the maximum output of the actuator. Although *this con-dition causes the vane to close, it also limits the maximum torque seen by the shaft to that of the maximum actuator output.

Ten (10)' inch Press.e Relief Butterfly valves4t additional questions

1. There are no other electrical components, other than solenoid valves which are required to be activated in order for the system to be operable when required.

2. The accumulator system is not seismically designed to the plant requirements. However, as indicated in the original data submittal, there is sufficient torque available without air assistance to close the valve.

3.1 The solenoid valves on the valve located inside the contain-ment have been seismically and environmentally qualified.

They are replacement solenoids for the solenoids originally furnished with the valves.

The solenoid valves on the valve located 6utside the contain-ment were originally furnished with the valves and have been seismically qualified only. This valve would function pro-perly if the ~ocation of the incident which caused a harsh environmental condition was inside the containment. There is presently a commitment to replace these solenoid valves with fully qualified solenoid valves before June 30, 1982. See attachment No. 1 which is Basis 17 of environmental qualifi-cation report dated Dec. 1, 1980.

The environmentally *qualified solenoid valves (ASCO NP series) were tested in accordance with IEEE 323-1974. Tests were per-formed on components of generi~ally equivalent designs.

3.2 The valve actuators and originally furnished solenoids were seismically qualified only. The qualification was accomplished by testing components of identical design. A seismic test report, Acton Laboratories No. 11262, on a test performed for Masoneilan is attached. See attachment No. 2.

3.3 There are no other electrical components required to be activated in order for the system to be operable when re-quired.

4.a The valve assembly was seismically qualified by test. A seismic test report, Acton Laboratories No. 11262, on a test performed for Masoneilan is attached. See attachment No. 2.

4.b A review of the margins of safety (previously submitted) for the possible failure mode of the valve shows adequate strength to withstand concurrent loading by both LOCA and Seismic events. The most critical element is the shear pins when subjected to actuator seating load. A seismic event should not increase the loading on the pins because the vane i~

being supported by the liner when sealed.

4.b (Cont'd)

An operability requirement was part of the seismic test.

The valve o~erated properly before, during, and after the simulated s~esmic event.

5. A preventative maintenance program has been established and is being followed for the solenoid valves which have been environ-mentally _qualified. Originally, no recommended maintenance procedures for the valve or actuator were provided by the valve manufacturer. Corrective maintenance is done on the valves and actuators as required based on periodic testing results.

6. The in-service testing is presently being conducted per Salem Technical Specifications, sections 4.6.3.1, 4.6.3.2, 4.6.3.3, 4.6.3.4 and 4.6.3.5 (see attachment No. 3). This testing follows paragraph lWV-3400 of the ASME section XI code.

36.0 Inch Purge Butterfly Valve

1. The manufacturer has not specified a valve seat design life.

Valve seat replacement is based on the leak rate testing -

results.

2. The in-service testing is presently being conducted per the Salem Technical Specification sections 4.6.3.1, 4.6.3.2, 4.6.3.3, -4.6.3.4 and 4.6.3.5 (see attachment No. 3). This testing follows paragraph lWV-3400 of the ASME section XI code.

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Basis No. 17 Deficiency: Documentation I"nsufficient (Containment Isola-tion Solenoids Outside the Containment)

Justification:

• The solenoid valves must only operate for a very short period of time. They deenergize in order to close their re-spective containment isolation-valve. Ope_rability is based on a failure analysis .performed by Westinghouse (NS-CE-755) vhich indicates that the failure mode of this type of sole-

. noid valve is in tbe closed (fail safe) position thereby as-suring isolation valve closure. These solenoids are located in* enclosures which provide thermal protection and minimize thermal rise transients.

The outside containment isolation valves' solenoids function to provide control for closing the redundant isolation valves during accidents inside containment. The outside is-olation valves' solenoids are not subjected to the contain-ment environment. The valves could be exposed to harsh en-vironments caused by high energy line breaks in the penetra-tion area. These breaks, however, do not require complete containment isolation.

( The postulate9 breaks in question are small steam breaks~

steam* generator blowdown and steam feed to auxiliary feed-water pump turbine. Following the postulated break, temp-eratures do not exceed 200°F until after ten minutes. *Se-lected lines for isolation may be required and operability should occur within this time span.

Existing information indicates that these valves would close in the environment caused by high-energy line breaks, and that any subsequent failure would tend to keep the valve closed *. Because of this, and the protection afforded by the solenoid valve enclosures, we conclude that the valves would remain in the safe position.

This case has been classified as a Group II.3 item (II.3.A).

Corrective Action:

These solenoid valves will be replaced with qualified de-vices pri'or to June 30, 1982. The installation schedule will be accelerated as equipment becomes available and plant operating conditions permit installation.

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M P80 108 02/60 Rev. l