ML072841071

September 2007 Evidentiary Hearing - Intervenors Exhibit 22, Gpu Nuclear, Clearing of the Oyster Creek Drywell Sand Bed Drains

ML072841071
Person / Time
Site:	Oyster Creek
Issue date:	03/03/1989
From:	GPU Nuclear Corp
To:	NRC/SECY
SECY RAS
References
50-219-LR, AmerGen-Intervenor-22, RAS 14335
Download: ML072841071 (8)

Text

I Citizens Exhibits 22 DOCKETED USNRC R'4S /'1335" 05/I1G/06 09:48:43 October 1, 2007 (10:45am)

OFFICE OF SECRETARY RULEMAKINGS AND ADJUDICATIONS STAFF Ifi]Nuclear isio No o

Budget Technical Data Report Activity No.

402873 Page 1 of 6 Project:

UMYELL Departnent/Section E&D Mech. C0axonents SAND BED LM T47-EAXE412E Release Date Revision Date Document

Title:

CrEARaNG OF ME OYSTME CREEK DMMWELL SAMND BED DRAINS Originator Signatur Date (s) Signature Date Does this TER include reo nuxdation(s)?

_ Yes[j No If yes, TFWR/r AT-5691, AT-5692 Mech Distribution Abstract:

• G.R. Capodanno Statenent of Problem

• M.O. Sanford On October 26, 1988 during the drywll cathodic pro-

• D.K. 'Craneberger tection core bore installation (B/A 402873) standing

• A.H. Rone - 0C water was f2ond in the drywell sand bed cushibn.

• R.E. Brown -

OC Inspection of the sand bed drains disclosed that a

• E. F. 0 'Connor small drip was present at four of the five bay

• J.D. Abramovici drains (3, 11, 15, & 19).

Since dripping is not

• D.G. Slear considered representative of drainage, it was con-F.P. Barbieri sidered prudent to "clear the sand bed drains".-

• R.L. Lorenzo R.F. Smith - 0C S

• E.J. Scheyder-.0 The sand bed drains and sand beds were cleared and A.R. Aiken - OC agitated. This resulted in collection of 514 gallon of water over a span of 4 weeks (31/16/88 to 12/16/88).

Although each of sand beds have been agitated, water is still dripping from the drain pipes. (Feb. 2, 1989)

(For Additional Space Use Side 2)

This is a report of work conducted by an individual (s) for use by GR] Nuclear Corporation. Neither CPU Nuclear Corporation nor the authors of the report warrant that the report is complete or accurate, Nothing contained in the report establishes conpany policy or constitutes a ccmmnitmnt by GCJ Nuclear Corporation.

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OCLR00028912

05/16/06 09:4B:43 Ab6txact Continuation TDR No.

897 Revision No.

0 Conclusion Sand bed drains from elbow to sand bed were agglomerated thus preventing water from draining and have been cleared.

Recoerjdation 1,

Install a catch basin under each sand bed drain and route poly tubing to individual 5 gallon poly containers at respective bays at the perimeter of the torus.

This container should be monitored and reported to Technical Functions on a weekly basis by plant operations.

This is being accomplished by Reference I.

2.

Place sand bed drains on planned maintenance schedule to be accessed and agitated at the next planned outage(13R).

TR AT-5691

3.

Review recoammeations made in TER 831 and assess if further drying of the sand can be effectively acomlished.

IR AT-5692 la 0CLR00028913

05/16/06 09:48:43 TM¶ 964 Rev. 0 Page 2 of 6' TABLE OF _OMXEM Sections 1.0 2.0 3.0 4.0 5.0 6.0 OJNCLUSICNS RENETIONS REFm*ES 3

4 4

5 6

6 2

3 4

5 6

Sewer Rooter senior Sand Bed Drainage Clearinq of Sand Bed Drains Sand Bed Graph pepresentation Sand Bed Water Samples Sand Bed Sand Sample Location i-I to 1-6 2-.

3-i 4-i to 4-5 5-1 to 5-3 6-1 to 6-2 OCLR00028914

05/16/06 09:48:43 TDR 964 Rev. 0 Page 3 of 6

1.0 INTRODUCTION

On Oct 26, 1988 during the cathodic protection core bore operation (B/A 402873) it was noted that hole 2 in bay ii was filled with standin water.

This water when tested by O.C. cheaistry was found not to be core bore water used during the drilling operation but rather it had characteristics of "old" fuel pool water.

Since the reactor cavity had not been filled with fuel pool water for the "ilzoming refueling" it was postulated that this entrapped water could be "old" fuel pool water.

It was estinated that a quantity of 400 to 550 gallons was present in the sand bed region.

An inspection of the five(5) sand bed drains disclosed that only a small drip was present at four of the drains(3, 11, 15, & 19).

Since the level of this water in the core hole of bay 11 did not decrease and the dripping was not conridered representative of drainage, it was considered prudent to "clear the sand drains".

Consequently, a work order was issued to "clear the sand bed drains".

1.1 There are drainage dharmels in the bottom of the 35 foot dia sand bed that slope toward five 4" Sch 40 sand filled drain lines.

The five drain lines are located beneath every other downcomer nozzle in bays 3, 7, 11, 15 and 19.

Each of the drain" line runs vertically (approximately 15 inches) from the sand area to a 90D elbow and down a slopped pipe (1" per foot) for approxinately 9 feet 6 inches through the concrete foundation before penetrating into the torus room.

Each pipe drain has a 100 mesh S.S. screen to retain the sand in the line.

Rrmoving the screen and examining each of the pipes revealed that only one drain pipe (bay 11) had sand in the pipe.

The remainder of the drain pipes were partially empty of sand.

0CLR00028915

05116106 09!48:43 TDR 964 Rev. 0 Page 4 of 6 2.0 MElHODS Scaffolding had to be built in each bay to access the drain pipes.

In addition each of the five 4" sch 40 drain pipes were cut back to, gain access to the end of the pipe.

As a precaution to a sudden discharge of water or sand, a specially designed 4" test plug with a 2" threaded connection was installed in the end of each of the 5 pipes.

To this connection a 2" tee was assembled so that a machine driven 3/4" dia snake (Attachment 1) could be inserted into the pipe.

A 1/2" ball valve along with a poly catch funnel was installed under this assembly to collect any water resulting from the cleared sand bed.

Both the 2" ball valve and catch basin were nanifolded together to a 1/2" poly tubing which was then routed under the torus to a 55 gal drum.

This arrangement was made to each of the five sand bed drains.

The machine driven 3/4" reinforced snake was fitted with various cutting accessories (Attacmuent 1) to clear the sand packed drains.

Specifically a spear head was used to 'cpen the way followed by progressively changing to larger cutters (2-1/2" dia).

A wet vacuum was also used to assist in the clearing and collecting of sand and water samples.

3.0 RIUEMS Although prdblems kept cropping up to delay the goal of clearing the water from the sand beds, the clearing of each of the drains was finally completed on Decesber 9, 1988.

Me total water collected as of Dec. 16, 1988 a-nouted to 514 gallons.

Graph (Attachment 2) shows the total water collected and a bar chart (AttadhTent 3) shows the progression of clearing of each drain.

Bay 11 was chosen as the first drain to clear because of the water fotrd in core hole 2 of the drywall cathodic protection program (B/A 402873).

Using a hand held drain cleaner with 1/2" cable and various cutting tools proved to be unsuccessful after many configuration changes.

Monsequently, it was decided to move to bay 15.

Upon removing the screen at the end of the pipe a second screen(original screen) started to discharge water at a veryýfast rate. In the course of seven days 192 gallons of water was collected.

Since bay 15 was draining on its own, a decision was made to proceed to bay 3.

Using a 1/2" dull drill point on the hand held "Super Vee" drain cleaner (Attachment 1) a break was made in the hard sand packed area beyond the 90° elbow.

Water poured out of this drain at a very fast rate.

In the course of two days 82 gallons were collected.

0CLRO0028916

OS/16/06 09!48:43 TDR 964 Rev. 0 Page 5 of 6 Because of the difficulty encountered using the hand held drain cleaner a larger capacity, heavy duty machine was obtained Setting up the heavy duty machine in bay 7 resulted in accessing the sand bed and agitating the sand to a distance of six feet beyond the 90' elbow.

Water came out of this drain in a small stream.

The amount collected in four days aonted to 28 gallons.

On Decamber 14, 1988 the total collected amounted to 42.3 gallons.

Ths drain had never been recorded as "dripping'.

The drain pipe in bay 19 was then accessed and the machine driven 3/4" cable and 2-1/2" dia cutter was moved in and out to agitate the sand bed six feet beyond the 90° elbow.

No excessive water appeared from this exercize however the cable and cutter shm-ad evidence of dasp sand.

A total of 2.6 gallons was collected as of December 14, 1988.

The drain pipe in bay 11 was then accessed using a s*all 1/2" spade type cutter.

Hmwever, enlarging the hole proved to be difficult and time ccnzsung until a specifically designed auger was used.

Specifically, the sand was packed tightly and gaining access to the sand bed was slow and tedious.

Finally after much persistence and "elbow grease" the sand bed was accessed.

The sand bed was accessed 28" beycrd the 90- elbow and the 3/4" cable with a 2-1/2'cutter was moved in and out of the sand bed to agitate the sand bed.

It was decided to "hold up" cmpletely accessing the sand bed because the cathodic protection anodes were already installed in this bay.

A small amount of water was found in this bay as evidensed by the damp sand on the cable and cutter.

Although bay 15 and bay 3 were draining it was decided to go into the drains and subsequent sand beds to agitate the sand beds.

This was accrplished in both bays and the 3/4" cable with associated 2-1/2" dia end piece was moved in and cut of the beds at a distance of six feet from the 90 elbow.

A graphic representation of access to each of the sand bed drains is shown by Attachment 4.

4.0 mCNCIJSICNS It was difficult to access the drywell sand beds from each of the sand bed drains.

However, it was finally accoaplisbed and a total of 514 gallons of water was collected as of December 16, 1988 (Attachment 2).

The water had all but stepped from each of the drains.

Water sanples were collected from each bay drain and analysis proved to be inconclusive (Attachment 5 and Reference 2).

0CLR00028917

05/16106 09:48)3 TDR 964 Rev. 0 Page 6 of 6 Sand samples were collected from several bays and analyzed as to why the sand was impervious to draining of water fram the sand bed (Attachuent 6 and Reference 3 and 4).

5.0 RE0m4ENDMON I.

Install a catch basin under each sand bed drain and route poly tubing to individual 5 gallon poly containers at respective bays at the perimeter of the torus. Ths container should be mvnitored and reported to Tedc Functions on a weekly basis by plant operations.

This is being acca*plished by Reference 1.

2.

Place sand bed drains on planned maintenance schedule to be accessed and agitated at the next planned outage(13R).

3.

Review recomendations made in TIm 831 and assess if further drying of the sand can be effectively acomplished.

6.0 REFERENCES

Reference 1 Mmo 5310-89-001 "Surveillance of the Oyster Creek Drywl Sand Bed Dr-ins in the Torus Room" dated 1/4/89 from J.A.

M3arting to L. Milligan.

Reference 2 IMe 2210-89-020 "Drywell leak off Samples" dated 1/16/89 frcm W. dunphy to G. R. Taylor.

Reference 3 Ykm 539 0-89-0002 "Drywell Sand and Water Analysis" dated 1/3/89 from P. R. Walton. to G.R. Taylor.

Reference 4 Report 5393-89-0116 "Drywell Sand and Water Analysis" Oyster Creek frcm M. J.

Chelius to G.R. Taylor.

OCLROO028918

The following plan is in place for inspecting for leakage around the Drywell:

Prior to Refuelinp_ Outage

- A camera inspection is performed to ensure the cavity trough drain line is free of any debris that could cause the trough to overflow and run down the drywell shell. (PM 18703M)

During Refueling Outage

- Strippable Coating is applied to the Reactor Cavity and Equipment Pool to minimize leakage.

- A camera inspection is performed while the cavity is flooded to ensure debris has not clogged the drain. (PM 18703M)

- After flood-up, inspections commence to determine if leakage is occurring, and to quantify the amount of leakage. The frequency of inspections is a minimum of once per day. The inspections will continue while the cavity is flooded. After drain-down, the inspections will continue until leakage has stopped. Inspection locations include poly bottles in the Torus room, concrete around vent pipes as viewed from the top of the Torus, Cavity and equipment pool drains, and electrical penetrations on 23' & 51' elevations. (PM 18704M)

During Run Cycle

- Inspections are performed on a quarterly basis to check for water in the Torus room poly bottles and leakage from the cavity trough drain. (PM 18705M)

Note: Water was found in 3 poly bottles in March 2006. This water was believed to be from past refueling outages. A sample of the water was taken in April 2006 and was found to have no activity. The bottles have been inspected twice since March (The latest inspection was May 26, 2006), with no water found.

OCLROO013354