ML18082B212
| ML18082B212 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/17/1980 |
| From: | Mittl R Public Service Enterprise Group |
| To: | Miraglia F Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8009220266 | |
| Download: ML18082B212 (4) | |
Text
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PS~G*
Public Service Electric and Gas Company 80 Park Plaza Newark, N.J. 07101 Phone 201/430-7000 September 17, 1980 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Attention:
Mr. Frank J. Miraglia, Chief Licensing Branch 3 Division of Licensing Gentlemen:
ADDITIONAL INFORMATION CONTAINMENT SUMP PERFORMANCE NO. 2 UNIT SALEM NUCLEAR GENERATING STATION DOCKET NO. 50-311 PSE&G hereby submits, in the enclosure to this letter, additional information regarding containment sump post -
LOCA performance to supplement the information transmitted to you by letter dated August 25, 1980.
Should you have any questions in this regard, do not hesi-tate to contact us.
CC:
Mr. Leif Norrholm Salem Resident Inspector BS07/l The Energy People r; oo922v as&
Very truly yours, R. L. Mittl General Manager -
Licensing and Environment Engineering and Construction 95*0942
ADDITIONAL INFORMATION CONTAINMENT SUMP POST-LOCA PERFORMANCE NO. 2 UNIT SALEM NUCLEAR GENERATING STATION The following information supplements PSE&G's August 25, 1980 submittal in response to NRC request for additional information dated July 21, 1980.
Item numbers refer to the August 25, 1980 submittal.
- 3.
We have reviewed our Emergency Instructions for ECCS operation during the recirculation cooling mode and have determined that adequate guidance is provided to the operators for monitoring ECCS systems performance.
During this mode, one operator will be delegated the principal responsibility of monitoring the performance of the ECCS systems.
Assessment of pump status and ECCS degradation will be made by cognizant technical personnel utilizing appropriate reference material (pump curves, etc.) to be made available in the Tech-nical Support Center.
This assessment and other tech-nical information will be readily available to the operators in the Control Room.
Additionally, a post-accident log will be initiated as part of the Emergency Duty Officer's Check Sheet for the purpose of monitor-ing and trending low pressure injection system perform-ance.
4a.
A specific, detailed insulation survey, together with insulation drawings, will be submitted prior to startup following the first refueling.
4c.
Paint chips accumulating on sump screens have pre-viously been considered by use of coatings that can endure accident conditions without peeling (FSAR Ques-tion 5.18).
Other sources of debris include Colemanite (used instead of sand in blowout plugs), thermal insu-lation, and debris from failed structures or compo-nents.
Thermal insulation consists of mirror insula-tion (RCS and other related systems) as well as other types of engineered insulation.
In all cases, the insulation is designed to remain intact and in place under accident conditions, except for insulation directly impinged upon by a high energy pipe failure or missile.
Since insulation is likely to remain in large fragments and not float well, it is unlikely that any significant quantity of insulation debris would be M P80 85 11/l
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If transported to the sump.
This conclusion is based on the great number of obstructions in the form of piping of varying sizes, pipe hangers, snubbers, pipe support members, structural steel, platforms, cables, motors and stairways, to the passage of large insulation debris to the sump.
Similarly, other large fragments or debris, if substantially heavier than water, will not float and therefore, not be transported to the sump, or, if substantially lighter, will float on the water surface above the sump screens.
4d.
Mirror insulation consists of stainless steel sheet metal and foils engineered to be structurally stable except in event of direct impingement, etc.
The only other material in this type insulation at Salem is Johns-Manville Cerablanket, a ceramic fibrous insulat-ing material with a density of 6 lbs/ft3.
Less than 5 ft3 of this material is used within the Salem No. 2 containment, and it is applied to irregularly shaped areas where reflective insulation alone would be inef-fective, such as edges or tops of pumps, etc.
The Cerablanket is enclosed in 0.006-in. metal foil, and then further enclosed in reflective insulation struc-ture.
Given the small amount of this material in use, its distribution over several locations, and its inte-gration into the insulation design, it is unlikely that any significant amount would become debris at all.
In any event, the great number of obstructions to passage to the sump (see 4c., above) would further reduce the quantity arriving at the'sump.
5,6. The referenced drawings were inadvertently omitted from the August 25, 1980 submittal.
The following drawings have subsequently been submitted:
204804 A 8752 201118 A 8707 204805 A 8752 201120 A 8707 204806 A 8752 201121 A 8707 204807 A 8752 201122 A 8707 204808 A 8752 201123 A 8707 204809 A 8752 201124 A 8707 201111 A 8707 208055 A 8811 201114 A 8707 208056 A 8811 201116 A 8707 208915 A 8823 201117 A 8707 M P80 85 11/2
- 6.
Colemanite is used in lieu of sand for blowout plugs.
We have calculated that assuming one RPV nozzle breaks and drives all the nearby blowout plugs up into the air, and further assuming that 25% of this coarse, heavy material is transported to the sump screens, where it all spreads uniformly over the screens to block them, that the screens will be only 16% blocked.
Clearly, the assumptions made are conservative, and even if realized-in an accident, the 16% blockage does not hinder sump performance since the sump screen design assumes 50% blockage while retaining full design capability.
Model testing is being conducted to verify the design.
EAL:peg M P80 85 11/3