ML20045A999
| ML20045A999 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 06/10/1993 |
| From: | Stratman R CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-93-002, IEB-93-2, NUDOCS 9306160052 | |
| Download: ML20045A999 (5) | |
Text
.
(
- l
- CENTERDO'? -
ENERGY
= PERRY NUCLEAR POWER PLANT Mait Address.
PO. BOX 97 Robert A. Stratman J [0 f ER ROA PERRY, OHIO 44081 VICE PRESIDENT - NUCLEAR i
g9 OM
~
(216) 259-3737 June 10, 1993 PY-CEI/NRR-1667 L i
~
s U. S. Nuclear Regulatory Commission Document Control Desk Vashington, D. C. 20555 Perry Nuclear Power Plant Docket 50-440 Response to NRC Bulletin 93-02:
Debris Plugging of Emergency 4
Core Cooling Suction Strainers Gentlemen:
On May 11, 1993, the Perry Nuclear Power Plant received the subject NRC Bulletin concerning the potential loss of net positive suction head for Emergency Core Cooling Systems (ECCS) due to debris plugging of ECCS strainers.
NRC Bulletin 93-02 requested licensees to identify fibrous air filters or other temporary sources of fibrous-material, not designed to withstand a LOCA, which are installed or stored in primary containment; to taxe immediate compensatory-measures which may be required to assure;the functional capability:of the ECCS; and'to take' prompt action to remove such material. The enclosed response-to NRC Bulletin 93-02 is written to satisfy the reporting requirements contained
.In-the Bulletin.
Identification of sources of fibrous material and actions taken to remove such I
material'has been provided'as part of the Perry Nuclear Power Plant response to' Confirmatory Action Letter RIII-93-07, which vas transmitted to the NRC on May_9, 1993 by letter.PY-CEI/01E-0402 L.
Additional related information was-provided by Perry Licensee Event Report 93-011 and letters PY-CEI/0IE-0404 L and PY-CEI/0IE-0405 L.
If you have any questions please feel free to call.
Sincerely,
.r
/ / /-
.fu (Ahlk1t-Robert A. Stratman j
f RAS:LF3:ss 00 6 -
Attachment Enclosure cc: NRC Project Manager
]
1 5
NRC Resident Inspector Office opekcoMes" III i
- Dev$cnc Dettnc Illummotmg
.l
_ TD400 Edson.
gl 9306160052 930610
- F" J
PDR ADOCK 05000440 G
j 1
In accordance with the oath and affirmation requirements of Section 182a of the Atomic Energy Act of 1954 as amended, and 10 CFR 50.54(f), I, Robert A.
1 Stratman, being duly sworn and deposed, state that (1) I am Vice President, Nuclear - Perry of the Centerior Service Company, (2) I am duly authorized to execute and file this certification on behalf of The Cleveland Electric Illuminating Company and Toledo Edison Company, and as the duly authorized agent for Duquesne Light Company, Ohio Edison Company, and Pennsylvania Power Company, and (3) the statements set forth herein are true and correct to the best of my knowledge, information and belief.
i L/ff/ltT
/
/ Robert A. Stratman Svorn to and subscribed before me, this
/
day of ox2__
l 0
ldiu WhksY
/l
/
JANE E. MOTT
</
/
W PubDc. State of Ohio
/ [ %MMon expires Feb. 20.1005
@ corded in Lake Cow.ty)
/
t l
FORM /3788/SS i
I I
l i
- - _ ~
t PY-CEI/NRR-1667 L Page 1 of 3 f
RESPONSE TO NRC. BULLETIN 93-02 t
i On May 11, 1993, Perry Nuclear Power Plant received NRC Bulletin 93-02 regarding debris plugging of Emergency Core Cooling Suction Strainers. The subject NRC Bulletin requested licensees to take the following actions:
1.
Identify fibrous air filters or other temporary sources of fibrous material, not designed to withstand a LOCA, which_are installed or stored in primary containment. Take immediate compensatory measures which may be required to assure the functional capability of the ECCS. Take prompt action to remove any such material. Because of the low probability of a LOCA event, the staff considers removal of this material at the next shutdown, or within 120 days, whichever comes first, to be sufficiently prompt.
If the facility is currently in shutdown, removal of such material is requested prior to restart.
In addition, the Bulletin required submittal of the following written reports:
1.
Vithin 30 days of the date of the Bulletin, submit a written response stating whether the actions requested above have or vill be performed.
If the use of such material is identified, the written response shall also include the locations and quantity of use, any immediate compensatory measures taken, and the current schedule ~for removal of the material.
2.
Vithin 30 days of completion of the requested action, submit a report confirming completion.
3.
If a licensee proposes not to take the requested actions, provide to the NRC staff, within 30 days of the Bulletin, the proposed alternative course of action and justification for' deviations from the requested action.
With regard to the above requested actions and reporting requirements, the following actions regarding identification and removal of fibrous material 3
vithin primary containment have been completed, as addressed in Perry Nuclear i
Pover Plant letter PY-CEI/01E-0402 L, dated May 9, 1993 which partially responded to Confirmatory Action Letter RIII-93-07.
Insulation A reviev vas performed to re-examine the types and. locations of insulation in containment and dryvell. This consisted of a documentation reviev supplemented by actual plant walk. downs of the containment and dryvell areas.
The Containment Vessel Cooling System (Mll), located throughout containment,
[
is insulated with two (2) inch thick fiberglass board and vrapped with an aluminum jacket and banded in accordance with manufacturer requirements. This installation is acceptable for accident conditions inside containment above i
the pool svell region.
The review discovered that some of this l
l f
l
t i
PY-CEI/NRR-1667 L l
~
Page 2 of 3
. metal-jacketed fiberglass board insulation was installed in the pool swell area. This was determined to be an unacceptable condition and the insulation was subsequently removed by a design change.
The issue of the use of NUKON insulation on piping in the dryvell was evaluated. A physical inspection of the dryvell was performed to confirm that l
NUKON vas the only type of insulation used on piping in the dryvell.
Based on the results of the testing performed in the Owens-Corning Topical Report t
(OCF-1), the NRC's evaluation of this report, and the Perry plant specific evaluation described in Section 6.2.2.2. of the USAR, it was concluded that i
the use of NUKON in the Dryvell was acceptable.
In addition, a revi n of the l
plant specific USAR's for Grand Gulf, River Bend, and Clinton nuclear power plants indicated similar analyses and conclusions were obtained with regards to dryvell insulation.
The inside of the dryvell cooling (M13) air handling units have Owens-Corning Type 703 fiberglass insulation with FRK-25 foil facing as an anti-sveat agent.
The insulation is held in place with glue and weld pins.
All joints, veld i
pins and exposed edges were coated with sealer. According to discussions with Owens-Corning technical staff, the insulation vill not degrade if it is exposed to water for an extended period of time, and this installation vill maintain insulation integrity when exposed to vater. However, the insulation facing could degrade over a period of time since it is a paper base. Once the dryvell is flooded, the vater in the area of the lover H13 cooler internal surfaces is expected to be in a stagnant cont.ition which would permit any degraded paper facing to sink to the bottom of the M13 cooler. Therefore, it was determined that this insulation is not a source of debris that could be transported to the suction strainers post-LOCA, and the insulation inside the M13 air handling units vill remain installed.
The 3M Interam E-50 Series material was used in various areas of containment, including pool svell area, to provide a " radiant energy shield" between a fire involving safe shutdown equipment and circuits and the redundant train.
To-obtain a fire resistance rating, the E-50 flexible vrap system was tested per ASTM 119, which included direct-impingement of a solid-fire hose stream after fire exposure. It was also subjected to environmental tests which included
. immersion in water for 90 days with no loss of exothermic properties. Vith the physical attachment provided by the stainless steel banding and the
.i aluminum facing and tape over the seams to protect the materia 1'from vater, it is not probable that the radiant energy shields vould become dislodged or deposit any fibrous material in the suppression pool during pool swell or normal operations. As fire barriers, the integrity of the vrap assembly is inspected on an 18 month cycle as part of PTI P54-P054 Fire Barrier Visual Inspection for any tears or holes. Therefore, it was determined that this material is acceptable for use in all areas of containment.
The Containment Chilled Vater System (P50), also located in various areas of the containment vessel, is insulated with closed cell polyethylene type insulation.
Less-than ten (10) linear feet of this insulation.is located in
.the pool svell' region. The acceptability of.this amount of material in
-addition to the entire P50 system insulation throughout containment is based upon dw negligible water absorption capacity and a material density of two (N m nds per cubic foot.
?
i PY-CEI/NRR-1667 L l
L Page 3 of 3 l
I-p Ven'tilation System Filters The filter material for the Dryvell Air Cooler (M13) has been identified as l
l the major contributor to the recent RHR "B" suppression pool suction strainer l
fouling event. The purpose of the roughing filter is to help maintain-the Air I
Handling Unit (AHU) cooling coils clean from dust created as a result of maintenance or construction activity. This filter material is not required to.
be installed during power operation, and has been removed. The repetitive tasks for installing and removing the roughing filters vill have material accountability controls incorporated to ensure the material is properly E
installed (during outages) and removed from containment prior to startup.
Containment Vessel Cooling System (Mll) roughing filters were evaluated and found to be a minor contributor to the recent strainer fouling condition.
t These are 20"X20"X2" cardboard encased, corrugated, voven cotton on wire filter elements (36 total). These roughing filters have been removed.
The use.of filters in the Containment Vessel and Dryvell Purge System (M14) supply plenum was evaluated and not considered to be a potential problem. The M14 supply plenums are located outside of Containment and hence, the process 4
of changing out these filters can not introduce filter media into the suppression pool. Also, the plenum utilizes an American Air Filter."Vaticel"'
o type (or equivalent) roughing filter. These filters are built to be rugged j
vith all~ metal sides and contain a much better quality filter media than that in the M11 and M13 systems.
Because of the quality of these filters, together vith the lov velocity of air flov across them, and the limited run times of-L l-the M14 system, it is extremely unlikely that filter fines.vould get carried into containment and hence into the suppression pool. -Thus, no corrective action is deemed necessary for the M14 filters.
A physical inspection of the containment /dryvell determined that there are no other installed filters made of fibrous materials in those areas.
i Submittal of this response satisfies the action requested by the Bulletin reporting requirement number 2.
Reporting requirement number 3 is not applicable to' Perry since the requested actions have been taken.
.