ML20238F309

Forwards Final Rept Entitled, Blackness Testing of Boraflex in Selected Cells of Turkey Point Unit 3 Spent Fuel Storage Racks. No Indication of Gaps,Voids or Other Spatial Distribution Anomalies Observed.Related Correspondence

ML20238F309
Person / Time
Site:	Turkey Point
Issue date:	09/11/1987
From:	Frantz S FLORIDA POWER & LIGHT CO., NEWMAN & HOLTZINGER
To:	Cole R, Lazo R, Luebke E Atomic Safety and Licensing Board Panel
References
CON-#387-4364 OLA-2, NUDOCS 8709160070
Download: ML20238F309 (24)

Text

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f RELATED CORRESM6 NEWMAN- & HOLTZINGER, P.C.

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' JACM R. NEWMAN -

1615 L ST RE ET, N.W.

' WituAM E BAER.JR JOMN E. MOLT 28NGER, JR..

DOUGLAS L. BERESFORD Lo "I'8 JADE A, EATON WAS HINGTON, D.C. 20036 4 Pg"#,L.EL,TE,N.

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.JR PAUL M RECM 202 955 6600 SRIAN R OfSH

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EEORGE L. EDGAR JILL E. GRANT KATHLEEN H. SHE A gpj j ANDREW N GREENE*

DOUGLAS G GREEN

.E PAMELA A LA*EY MAROL LYN NEWMAN BOLA.

,! t rRANa R. uNow dowN t. sTOUGw. JR.

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. September 11 1987

^^'"'55" " " cot a*o" AV H GUTT RM N ER L PATTE R$O EDWARD J TWOMEY.

JANE I RYAN JAMES 3. WILCOX, JR PAUL J SAviDGE*

KEVIN P, GALLEN JACOL.YN A. SIMMONS THOMAS A. SCNMUTJ '.,

ROBERT H SOLOMON MICHAEL F. MCALY CHARLES C. THEBAUD JR.

ROBERT L WH!TE NANCY A. WHITE

• SCOTT A. MARMAN '.

ROBIN T, WlGGINS*

CTEVEN D. FRANTZ DAvlO B RASKIN ROBERT LOWENSTEIN DONAb $1LVERMAN N T C. BAYNARD, Ill JOSEPH E STUBBS or couwsc6 counsel.

• NOT ADurrytD IN D c.

Dr. Robert M.

Lazo, Chairman Dr. Emmeth A. Luebke Dr.-Richard F.

Cole Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission Washington, D.C.

.20555 In the Matter of FLORIDA POWER AND LIGHT COMPANY (Turkey' Point Plant, Unit Nos. 3 and 4)

Docket Nos. 50-250, 50-251-OLA-2 i

Dear Licensing Board Members:

Please find enclosed a copy of the final report of the

""lackness Testing of Boraflex in Selected Cells of the Turkey Point Unit 3 Spent Fuel Storage Racks" performed in August 1987.

As discussed in my letter to the Licensing Board dated August 21,.1987, no indication of gaps, voids, or other spatial distribution anomalies were observed in any of the Boraflex panels which were tested.

According to this report, the testing had the capability to detect gaps of approximately 1 to 1-1/2-inch or greater.

Sincerely, 1

Steven P.

Frantz i

Co-Counsel for Florida Power

& Light Company cc:

Service List i

B709160070 870911 5()

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. UNITED STATES 10F AMERICA DOCKEfE

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' NUCLEAR REGULATORY' COMMISSION.

BEFORE THE ATOMIC SAFETY AND LICENSING B Dp g pg,,g.

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In the Matter of'

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Docket Nos. 50-250 OLA-2 FLORIDA. POWER & LIGHT COMPANY'

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50-251 OLA-2

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(Turkey Point Nuclear Generating

)

Units 3 & 4)

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I

' CERTIFICATE OF SERVICE I hereby c'ertify that copies of;the attached letter in the above captioned proceeding were served on the following:

by deposit.in the United States mail, first class, properly stamped,and' addressed,'on the date shown below.

Dr. Robert M.

Lazo, Chairman

' Atomic Safety'and Licensing' Board Panel U.S. Nuclear: Regulatory Commission-Washington, D.C.

20555 Dr. Emmeth A. Luebke Atomic Safety.and Licer, sing Board Panel U.S. Nuclear Regulatory Commission-Washington, D.C.

20555 Dr. Richard F. Cole Atomic Safety and Licensing Board. Panel U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Atomic Safety and Licensing Appeal Board Panel U.S.. Nuclear Regulatory. Commission Washington, D.C..

20555 Office of Secretary U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Attention:

Chief, Docketing and Service Section (Original plus two copies)

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Joette Lorion 7210 Red Road #208 Miami, FL 33143 Colleen P.

Woodhead i

Office of Executive Legal Director

^

U.S. Nuclear Regulatory Commission l

Washington, D.C.

20555 Norman A.

Coll c_-

Coll, Davidson, Carter, Smith, Salter & Barkett 3200 Miami Center 100 Chopin Plaza Miami, FL 33131 4.

/*

Steven P.

Frantz Newman & P.oltzinger, P.C.

1615 L Street, N.W.

Washington, D.C.

20036 i,

Dated:

September 11, 19E7 f

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[7.

NST-103 BLACKNESS TESTING OF 7

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BORAFLEX IN SELECTED CELLS sJ SEP 9S87 OF THE TURKEY POINT UNIT 3

. Lb8Lbu U Lh s SPENT FUEL STORAGE RACKS Newman & Holtzinger, P.C.

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i

' Prepared for the FLORIDA POWER & LIGHT Co.

I by Stanley E. Turner, PhD, PE AUGUST 1987 NUSURTEC INCORPORATED Neutron Surveillance Technologies 239 Normandy Circle E.

Palm Harbor, FL 34683 l

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o-1,5 Introduction Neutron absorption (Blackness)' tests 'were made in

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j selected-~ cells of the Turkey Point Nuclear Unit' 3 spent fuel il storage, rack for the. purpose'of confirming 1the presence and 4

integrityzofLthe Boraflex. absorber material.

These>tects were made' on-August 5 and 6, 1987 using.a specially designed /

logging tool containing a Californium-252 neutron source and four boron triflouride (BF3) thermal neutron detectors.

l 3

During operation, the logging tool' is lowered intkthe O-)

storage pool and vertically traverses a

designated storage

/

n cell.

Fast neutrons from the Californium source pass through j

t the walls of the cell, become thermalized (moderated) i n the water of ' adjacent cells and diffuse (scatter) back toward the I

logging tool'.

-These' 'back-scattered thermal neutrons are j

absorbed in-areas of-the rack walls where the. absorber material is present and intact.

However, in areas where the absorber material' is missing or significantly degraded, g the-thermal neutrons will pass through and be registered ai

/

counts.by. the detectors inside the logging tool.

Increase's 1

in thermal neutron counting rates are interpreted a s' l

Indicating missing absorber material in the storage cell il L

being tested,-

while low counting rates confirm that the

]

absorber ma ter ial is present.

A high background of gamma radiation will interfere with the tests by reducing the sensitivity of the tests and by increasing the statistical variation in neutron counts.

Prior to performing the tests, spent fuel in the immediate vicinity of the area designated for the tests were moved away in order to min 1mize interference from gamma radiat ion.

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However, the spent fuel pool demineralizers were inoperative, j

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resulting:.in a high gamma radiation level from radionuclides

'in the-pool. water'.

The effect of -this high gamma radiation

.r.ievel was to reduce. the sensitivity of the measurements.

H e.ve r t he le s s,

the', measurements positively confirmed the

$1 presence of the'Boraflex in the eighteen cells' tested and did No not reveal evidence of any significant degradation.

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2.8 EUMMARY AND CONCLUSIONS I

A total of'18 spent fuel cells'were tested, of which 8 were in Region

~1 of the storage rack and 10 were in Region 2.

'These tests encompassed 32 full length Boraflex sheets in L

Region 1 and 22 sheets in Region 2,

in the locations and configuration illustrated in Figure 1.

In some cases, repeat measurements were made for additional confidence in the results.

Specific long term counts, taken in the pool water above the racks and in the poisoned sections near the bottom, confirmed that the Boraflex was present in the four walls of all cells tested, except along tne east wall of cells V7 through V11.

These walls are the boundary of Region 2 where the rack design does not require Boraflex.

In Region 2 of the strorage rack, single Boraflex sheets are sandwiched between the stainless steel walls of adjacent cells.

Measurements in two adjacent cells inherently

/

duplicate measurements from both sides of the common Boraflex I

sheet.

The Region 2 tests resulted in duplicate measurements i

from both sides on thirteen (13) of the twenty-two Boraflex sheets tested.

During vertical traverses with the logging tool, no indications of defects in the Boraflex sheets were 1

observed.

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Region 1 cells use the flux-trap concept with two Boraflex l

sheets between each storage cell.

The logging tool will respond primarily to the closest Boraflex sheet and to the neutrons thermalized in the water-gap.

The presence of the

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00 71 70 69 68 67 66 65 64 63 62 61 60 FIGURE 1 TURKEY POINT UNIT 3 SPENT FUEL POOL ~ ARRANGEMENT OF TEST CELLS AND SPENT FUEL IN STORAGE 4

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s Boraflex was confirmed by long term counts in the four walls of'allielght cells. tested (32 Boraflex sheets).

In the vertical. traverses, no indication of defects in.the Boraflex wasaobserved.

The gamma background radiation level during these tests was unusually.

high since

.the pool demineralized was not operating.

Above the pool,'the radiation level was ev ' 2 0 mR/hr' which suggests that in the storage cells where the

-measurements were being made, 'the radiatlun

'avel may have

.been las much as 1

or 2

R/hr. This required setting the counting instrument bias _ level high in order to minimize a

. interference by the gamma. background.

The high bias setting, in-turn, reduced the sensitivity of the measurements.

While in a low gamma. background, the measurements would be expected to detect gaps or defects of ev 0.5 to es 1 inch in the

Borellex, the high gamma background is estimated to have reduced the detection capability to gaps of

^s i to 1 1/2 inchs in width.

I

. Counting rates were measured both as the tool moved down through the cells (at a-7 feet' per minute) and as the tool was withdra wn.

In addition, the capability existed to stop the. tool at suspect locations for longer term counting.

However, no indication of defects were observed that would have justified this procedure.

Based on the measurements, it

.is concluded that the Boraflex in the Turkey Point Unit 3 spent-fuel racks is still present and essentially intact.

Florida Power and Light had selected cells for testing that had received the highest accumulated radiation dose.

On the basis of this fact and the total number of cells tested, the absence of observable defects provides reasonable confidence

'that the Boraflex sheets.in the remaining cells are capable of continuing to serve' their intended function of assuring

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criticality safety.

5

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3.0 SURVEILLANCE TESTS i

3.1 Equipment Description.

The measuring (logging) equipment consists of four essentially.identlical channels,- each including a boron triflouride (BF3) counter tube (1 inch diamenter by 12. inch length)'and pre-amplifier located in a water-tight stainless steel box that constitutes the underwater logging tool.

This

. logging tool also contains a Californium-252 source and is

sized-l8.4 inch outside dimension) to fit closely into the storage cells (8.85 inch.inside dimension in Region 1

and 8.80 inch in Region 2).

Insulated cabling connects the logging tool to surface instrumentation which includes a high voltage power

supply, linear amplifier, single channel analyzer (integral bias),

and count-rate meters for each channel, in addition to a multichannel strip chart recorder and timer / counter circuits.

3.2 Operational Procedures Detailed procedures are attached as Appendix A.

These procedures were reviewed and approved by the Turkey Point Safety Committee prior to the tests and were closely followed with the exception of Section 3 which speciflied a base-line count of 80,000 counts.

Because of the high bias required to reduce interference f rom the background gamma radiation, the base-line counts were reduced.

With the consent of the FP&L test director,the total counts were reduced to as20,000 counts in order to accomplish the testing within a reasonable

. time frame.

However, at 20,000 counts, the 95% confidence level (2 r ) would be less than 2% due to counting statistics alone.

This is more than adequate to confirm the presence of

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the.Boraflex absorber.

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c Because of the high bias level,.some difficulty was also experienced with drift-in the. instrument gain settings which required periodic readjust.lment of the gain.

To minimize any-potential error due to drift in the gain, base-line counts t

were taken for each cell (rather-than twice daily).with the:

. logging tool positioned first in the water above the cell and' then at the bottom of the cell being tested.

3.3 Test Results A total of 18 cells' were tested with 'both fixed. position

' counting and multi-channel recording of the counting rate as the logging tool vertically traversed the cell. Figures 2, 3 and 4 111ustrate'the recorder traces for'the three types of-cells tested, as the logging tool moved into and subsequently out of the storage cells.

These cell types are as follows:

Figure 2 Region 1 cell f

Figure 3 Region 2 cell (central), and Figure 4 Region 2 cell with no Boraflex along the East wall.

The recorder traces illustrate the drop in counting rate as the neutron detectors enter (or exit) the poisoned section of the cells.

Originals of the recorder traces (in color) and the data sheets have been submitted to FP&L under separate

. cover.

None of the recorder traces showed large peaks in counting rate that would be indicative of significant gaps in the Boraflex.

Small gaps

(<1.5"),

if present would be lost in the statistical variation of the counting rates.

Based on the recorder

traces, average counting rates (approximate) in the poisoned sections and in the water above each cell were determined visually.

Table 1 shows the counting rates in the poisoned section (Boraflex) of the 7

1 n, ;

storage cell-expressed.as a percentage of the' counting rate in water.

Also-shown.in Table-1 are results of the fixed-position.. counting expressed:In the same units.

These data

. confirm the presence of the Boraflex absorber in all cel?.s except along the. East wall of cells V7 through V11 where:

Boraflexsis-not used.

Because of differences

-in gain and and. the periodic adjustment of gain bias settings.

necessary to compensate for drif t -

the absolute counting rates could not'be 'directly. compared with values for other cells 1or for.other detectors..

Individual storage cell data,

however, confirm the presence of'a strong absorber at the locations where Boraflex was used.

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Table 1 Storage cell Counting Data

• as Percentage of Count in Water

1. 1 82

1. 3 54 LOCATION EEEI NORTH EAEI SOUTH U7-

'34 (22) 63 (38) 63 (34) 69'(39)

U8 43 (47) 66 (71) 70 (59) 73 (69)

U9 38 (39) 68 (64) 68 (56) 68 (69)

U10 20'(23) 59 (59) 66 (56) 51 (54)

Ull 5 (7) 23 (33) 37 (45) 18 (11)

V7 49 (-)

66 (-)

92 (-)

76 (-)

V8-59 (65) 63 (74) 90 (94) 75 (74)

V9 61 (66) 69 (69) 94 (94) 75 (74)

V10 47 (51) 64 (68) 92 (91) 66 (60)

Vil 16 (25) 44 (50) 88 (88) 26 (27.)

AA64 45 (46) 62 (60) 65 (56) 56 (63)

AA65 56 (52) 60 (62) 63 (60) 71 (70)

AA66 59 (56) 61 (63) 65 (54) 74 (67)

AA67 49 (54) 63 (64) 65 (54) 69 (67)

.BB64 46 (50) 63 (61) 56 (62) 71 (65)

BB65 55 (52) 62 (64) 64 (64) 72 (67)

BB66 60 (57) 60 (61) 68 (49) 73 (70)

BB67 56 (56) 62 (62) 66 (57) 70 (68)

• ~ Values are approximate averages from the strip chart records as determined by eye. Parenthetical numbers are fixed position counting data.

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Figure 4 Region 2 Storage Cell with no Boraflex along the East Wall 12

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APP MDIX A OPERATING PROCEDURES 1

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NUSURTEC INCORPORATED BLACKNESS TESTING' PROCEDURES FLORIDA POWER AND LIGHT CO.

TURKEY POINT PLANT A.

PURPOSE l

The purpose of the Blackness Testing is to confirm the presence and integrity of the Botaflex absorber material in the spent fuel storage i

l racks of the Turkey Point Nuclear Power Plant.

A secondary purpose is to establish a baseline as a reference for com-parison with f uture measurements.

B.

REFERENCES Discussion of Blackness Testing attached.

C.

PRE-REQUISITES 1

Test equipment shall be on site and available for use.

2.

Services required are a source of 110 V, 69 cycle power and clean demineralized water to rinse (decontaminate) the testing tool after use.

3.

A laydown area is available at pool side to accommodate the test tool when removed from the water.

4.

Cell locations to be tested shall be designated by the FP&L Test

Director, 5.

An FP&L Test Director, or other person designated by FP&L, shall be present and available to witness the Blackness Tests and to independently confirm the cell locations in which the measurements are being made.

D.

PRECAUTIONS

1. The Blackness Test involves the use of a 215 microcurie Californium-252 neutron source with a radiation dose of 0.064 mr/hr gamma and 8.92 ar/hr neutron at one meter (total of 1 mr/hr).

All operations shall be subject to the FP&L Radiation Protection Department procedures.

2. Proper protective clothing and dosimetry, as specified by FP&L Rad Protection, shall be worn by NUSURTEC personnel.

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3. Crane operations shall be performed by qualified Fp&L operators and shall conform to existing safety rules for lifting, rigging and handling of equipment in and near the spent fuel storage pool.

4. All NUSURTEC personnel shall be aware of their responsibility for-their own radiation exposure in conformance with the ALARA principles.

E.

LIMITATIONS AND ACTIONS

1. Testing shall be performed in cells selected by the FP&L Test Director, or other person designated by FP&L, who shall also observe and confirm the cell and tool orientation of each measurement.

2. Whenever the source is loaded in the tool and the tool is not immersed in water, precautions shall be taken to prevent personnel from approaching closer than two feet from the source end of the tool.

3. Subject to the approval of FP&L Rad Protection, the Test Director, and the Fuel Handling Foreman, the testing tool containing the source may be safely lef t in an empty storage call overnight or otherwise unattended for relatively brief periods of time.

4. In the event of a high particulate air activity, operations shall be suspended and the equipment protected from contamination as much as possible.

5. In a plant energency, the equipment shall be turned of f and the tool (with source installed) stored in an empty storage cell.

F.

PROCEDURES

1. Equipment Set-up

a. Assemble the testing tool (except for the source) and connect the High Voltage, B+, and signal leads. Tighten and seal the feed-thru to assure water tightness.

b. Turn on the instrumentation and allow to warm-up and stabilize for at least 26 minutes before using.

2. Syste-Checkout and Adjustment

a. Install the Cf-252 source and lower the tool into the water to a depth of about 18-29 feet,

b. Check the counter tube plateaus and record the operating high voltage.

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c. Adjust the asplifier gains and discriminator settings to obtain approximately equal counting rates on the four 1

detectors.

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d. Adjust the recorder settings to give nearly full scale deflection over'.the range of each channel.

3. Establish Base-line Counting Rates (80,000 total counts or more) for the_following configurations:

a. With the source in water,

b. With the source in the upper stainless steel region of a storage cell,

c. With the source in the poisoned region of a typical cell,

d. Repeat of 3.c. above at a different location.

If the dif-ference is greater than 10%, repeat until consistent results are obtained (inconsistent results suggests a possible difference in the poison material.)

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e. Repeat measurements 3.a through 3.d at the beginning and end of each working day.

4. Measurements on Selected Cells

a. Position the testing tool in the entrance of a designated cell.

b. Record the cell location and orientation of the tool. Obtain confirmation from the FP&L Test Director or other person

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designated by FP&L.

c. Start lowering the tool through the cell. With a stopvatch, determine the approximate time to traverse the cell.

d. Start the chart recorder at the sane time as 4.c., noting a cross-reference to the cell location on the chart.

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e. When the tool reaches the bottom, note on the strip chart, j

and reverse the direction of travel of the tool, recording i

the counting rates as the tool is withdrawn.

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f. When the tool emerges from the cell, move to the next I

designated cell and repeat steps 4.a through 4.e.

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.i Note:

If one or more of the channels are not working, the blackness test may still be performed by rotating the testing tool and l

re-running the same cell with a dif ferent orientation.

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5. System Shutdown On Completion of Measurements

a. Remove the testing tool from the water, being careful to exclude personnel from the vicinity (two foot interval) of the source end.

b. Remove the source and return it to the shleided cask.

c. Dismantle and finse tool with demineralized water to decontaminate. Strip and discard sleeving.

d. Obtain survey from Rad Protection and clearance to remove the tool. If the tool cannot be adequately decontaminated,

1) remove those parts that are unrestricted.

2) if necessary, cut away and discard the tygon tubing.

3) as last resort, store equipment at FP&L until the NUSURTEC license to receive contaminated equipment is received and transfer is possible.

G. SAFETY ISSUES

1. Blackness testing does not affect any Technical Specification limit nor alter any margin of safety.

2. Blackness testing neither alters not affects the probability of occurrance or the consequences of any accident, nor does it create or contribute to the mal-function or f ailure of any equipment important to safety.

3. Blackness testirig does not introduce any new or un-reviewed safety issues.

H.

QUALITY ASSURANCE

1. Blackness testing is not, of itself, safety related.

However, the results of the measurements constitute one of the sources of data i

in a subsequent evaluation of the criticality safety of the spent fuel storage racks. Consequently, CA requirements for independent verification of critical steps in the measurements are necessary.

l Provision is incorporated in these procedures for independent verification by a representative of Florida Power and Light Co,

2. Critical steps in the measurements are the f ollowing:

a. Identification of the cello being measured.

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b. Verification of the orientation of the testing tool

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in the cell being measured.

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c. Consistency of base line counting rates before and af ter the measurements to preclude (or identif y the

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occurrance of) significant drift in the instrument response.

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,4 NEUTRON BLACKNESS TESTING OF SPENT FUEL STORAGE RACKS b.utron Blackness testing, using a sealed neutron source, is intended to measure thermal neutron attenuation in the walls of high density spent fuel storage racks of nuclear power plants. The objective of these measurements is

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to confirm the presence 'of the neutron absorber material prior to initial l

operation and/or to periodically verify the continued presence of the absorber I

material during long term storage of spent fuel assemblies.

During operation, a testing tool containing the Cf-252 source and and appropriate neutron detectors is lowered into the storage pool and verti-cally traverses selected storage cells. The testing tool is a stainless steel container incorporating a source holder and 1 to 4 thermal neutron detectors (BP3, He3, or scintillation type). As the testing tool traverses a storage cell, fast neutrons from the Cf-252 source pass through the walls of the cell, become thermalized (moderated) in the water of adjacent cells, and diffuse (scatter) back toward the testing tool. These back-scattered thermal neutrons are absorbed in areas of the rack walls where the absorber material is present j

and intact.

However, in areas where the ebsorber material is missing or i

significantly degraded, the thermal neutrons will pass through and be register-ed as counts by the detectors inside the testing tool.

Increases in thermal i

neutron counting rates are interpreted as indicating missing absorber material in the storage cell being measured, while low counting rates (ie, background or slightly above) confirm that the absorber material is present. The testing device may be stopped at suspect locations in the rack and counts obtained over a longer time period in order to improve the counting statistics and obtain more precise measurements.

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Source Handling Operations I

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During the measurement operations, the sealed Cf-252 neutron source will be under approximately 30 to 48 feet of water and will therefore present no radiological rit,k to operating personnel. However, the source is handled in i

the open air during transfer operations between the testing tool and the 1

shielde..i storage container. Manipulation is accomplished using a special hand-j ling tool which assures that the source is always maintained at least 24 inches away from the operator.

At this separation distance, the unshielded Cf source is calculated to result in a dose rate of 3.3 arem/hr (3.1 area /hr neutron and 8.2 mrem /hr gamma) to the operator.

Handling time is estimated to be less than 5 minutes.

Returning the source to the shielded storage container at the end of the measur eme nt operation will require approximately the same amount of time.

For a single loading and unloading operation during an ordinary work shift, the equipment operators would be expected to receive less than f.6 mrem.

In a typ-l-

ical rack inspection job requiring 4 to 5 working days, the operators total exposure will be less than 5 mrem (allowing for 6-7 loading / unloading operations per job).

In practice, the radiation dose to the operator from the Cf-252 source will likely be appreciably less than that received from the nor mal radiation levels in the v;cinity of spent fuel storage pools of most mature operating i

nuclear power plants.

The NUSURTEC operators vill be subject to the ordinary health physics procedures and personnel monitoring practices appropriate to each nuclear plant in which measurements are to be made.

Equipment Contamination During the in-pool measurement operations, the surface of the equipment (particularly insulated electrical cables to the under-water detectors) may become slightly contaminated from radionuclides normally encountered in spent fuel pool water. At the end of the measurement operations at a given plant, an effort will be made to decontaminate the equipment. The stainless steel of the testing tool is expected to be readily decontaminated. However, plastic sleeving on the electrical cables may remain contaminated in levels above that which may l

be considered as unrestricted. In the event that contamination cannot be reduced i

to acceptable levels, part or all of the electrical cabling will be abandoned as part of the plants waste.

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