UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, DC 20555-0001

March 3, 2004

NRC INFORMATION NOTICE 2004-05: SPENT FUEL POOL LEAKAGE TO ONSITE

GROUNDWATER

Addressees:

All holders of operating licensees for nuclear power reactors (except those who have

permanently ceased operations and have certified that fuel has been permanently removed

from the reactor vessel) and for research and test reactors, and all holders of fuel storage

licenses and construction permits.

Purpose:

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform

addressees of the recent identification of a longstanding leak to onsite groundwater from the

spent fuel pool of an operating pressurized water reactor facility. It is expected that recipients

will review the information for applicability to their facilities and consider actions, as appropriate,

to avoid similar problems. However, suggestions contained in this information notice are not

NRC requirements; therefore, no specific action or written response is required.

Description of Circumstances:

On September 18, 2002, the licensee for the Salem Nuclear Generating Station identified

evidence of radioactive water leakage through an interior wall located at the 24-meter (78-foot)

elevation of the Unit 1 auxiliary building mechanical penetration room, a radiologically controlled

area. The leak location, about 3 meters (10 feet) up a wall surface, was identified while the

licensee was following up low-level shoe contamination of personnel who had traversed the

room. The licensee established a comprehensive task action plan to identify and stop the

source of the leakage and evaluate possibly undetected leakage outside building structures. 

The licensee did identify other locations where radioactive water was leaking through interior

walls or penetrations into both the Unit 1 auxiliary building and the Unit 1 fuel handling building

(FHB). 

On February 6, 2003, the licensee identified the radionuclide tritium (H-3) in groundwater in two

test locations near the Unit 1 FHB. The test locations were within the licensee-controlled

restricted area. The licensee identified other locations of groundwater contamination in the

general vicinity of the Unit 1 FHB and within the restricted area. No other reactor-produced

radionuclides were detected in the groundwater sampling test locations. 

ML040580454
IN 2004-05

Page 2 of 4

The licensee obtained technical support and concluded (based on leak testing of suspect

systems, chemical analysis of water samples, system and building configuration reviews, and a

geohydrological evaluation) that the likely source of the tritium was the Unit 1 spent fuel pool

(SFP). The licensee believes that the leakage was the result of the obstruction of the leakage

detection and collection system of the SFP stainless steel liner.

Discussion:

The Salem Unit 1 FHB is a seismically qualified structure that contains the Unit 1 SFP. Unit 1

SFP support systems in the Unit 1 auxiliary building pass through adjacent building walls to the

Unit 1 FHB. The walls are separated by a Styrofoam® -filled 15-cm (6-inch) seismic gap and

the support systems traverse the seismic gap.

The Unit 1 SFP is a concrete structure with a stainless steel liner. The SFP includes an integral

liner leakage detection and collection system, consisting of an extensive network of collection

lines running both horizontally and vertically within the narrow gap between the SFP liner and

the concrete SFP structure. The collected liner leakage is discharged to a collection trough

through 17 drain lines (tell-tale drains). The tell-tale drains provide a means to detect, monitor,

and quantify potential leakage from the SFP liner. The collected leakage is subsequently

directed to the liquid radioactive waste system for processing. 

The licensee’s reviews discovered that over the years since initial facility startup, materials such

as boric acid residue and minerals accumulated within the leak collection and detection system

and restricted the normal drainage of liquid. The reviews also found that a modification to the

tell-tale drains in 1998 resulted in the inadvertent introduction of sealant into the tell-tale drains,

further restricting the free drainage of leakage from the liner. As a result, through-liner leakage

accumulated between the SFP liner and the concrete structure of the SFP. The accumulated

water, containing tritium, subsequently migrated to other locations through penetrations,

concrete construction joints, and cracks. The seismic gap was confirmed to contain water with

radionuclides characteristic of Unit 1 SFP water. The water is believed by the licensee to have

made its way to the groundwater in the restricted area via the seismic gap.

The licensee cleaned the tell-tale drains, improving the drainage of the accumulated water

between the liner and spent fuel pool concrete structure and stopping the through-wall and

penetration leakage. After the cleaning effort, the leak rate from the tell-tale drains increased

from about 19 liters per day (5 gallons per day) to about 380 liters per day (100 gpd). The

leakage was properly collected.

The NRC conducted a special inspection of this issue (NRC Inspection Report 50-272/2003-

006; 50-311/2003-006, ADAMS Accession No. ML032890212). The NRC’s and the licensee’s

reviews identified the following information about this situation.
IN 2004-05

Page 3 of 4

1. The licensee took actions to identify specific leak locations, repair and mitigate the leak,

and assess potential health and safety impacts. A comprehensive groundwater

sampling and analysis program was implemented. Although the licensee believes, with

a high degree of confidence, that the leak originated from the SFP, the licensee is

continuing evaluations to confirm this conclusion. The leakage itself was not

accompanied by large fluctuations in SFP water levels and was likely masked by

approximately equal volumes of evaporation from the SFP.

2. The licensee stopped the identified through-wall leakage by cleaning the tell-tales and

resumed controlled collection of SFP liner leakage via the installed leakage detection

and collection system. Extent-of-condition reviews revealed no apparent accumulation

of water between the SFP liner and concrete structure at Salem Unit 2.

3. The licensee’s evaluations did not identify any immediate health and safety

consequences to onsite workers or members of the public. No radionuclides associated

with the leakage were detected outside the onsite areas administered as accesscontrolled areas for purposes of radiation protection. The licensee did not detect any

tritium associated with this leak in areas accessible to the public (i.e., the unrestricted

area). The licensee subsequently developed and implemented an onsite groundwater

remedial investigation work plan in conjunction with State of New Jersey

representatives. 

4. The Unit 1 SFP had exhibited detectable leakage from the tell-tales since initial plant

operations. To monitor leakage from the tell-tales, the licensee established a

surveillance program. Over the years, the leakage from the tell-tales diminished but the

licensee was not able to tell from leakage changes if they needed further evaluation.

There was also a missed opportunity to evaluate earlier through-wall contaminated

leakage for possible accumulation of water between the Unit 1 FSP liner and concrete

structure.

5. There was no periodic maintenance of the SFP leakage detection and collection system

to ensure that drainage channels remained free and clear so that the system could

perform its design function of preventing water from accumulating behind the FHB walls. 

The licensee initiated actions to develop a cleaning and maintenance process. 

6. The licensee conducted evaluations of potential short-term adverse impacts to the SFP

structure. The preliminary evaluations did not identify any adverse effects that would

impact the design bases of the SFP or FHB structure. Nonetheless, the licensee

initiated laboratory testing of the effects of boric acid on concrete. The results of these

tests are being evaluated by the licensee for potential long-term effects.

The licensee developed numerous corrective action documents to track the review, evaluation,

and correction of identified deficiencies. 
IN 2004-05

Page 4 of 4

This information notice requires no specific action or written response. If there are any

questions about this notice, contact one of the persons listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

/RA/

William D. Beckner, Chief

Reactor Operations Branch

Division of Inspection Program Management

Office of Nuclear Reactor Regulation

Technical Contacts: Ronald Nimitz, Region I Stephen Klementowicz, NRR

(610) 337-5267 (301) 415-1084

E-mail: rln@nrc.gov E-mail: sxk@nrc.gov

Suresh Chaudhary, Region I Jason Jang, Region I

(610) 337-5335 610-337-5220

E-mail: skc@nrc.gov E-mail jcj@nrc.gov

Attachment: List of Recently Issued NRC Information Notices
____________________________________________________________________________________

OL = Operating License

CP = Construction Permit

Attachment

IN 2004-05

Page 1 of 1

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of 

Notice No. Subject Issuance Issued to

_____________________________________________________________________________________

2004-04 Fuel Damage During Cleaning

at a Foreign Pressurized Water

Reactor

02/24/2004 All holders of operating licenses for

light-water reactors, except those

who have permanently ceased

operations and have certified that

fuel has been permanently

removed from the reactor.

2004-03 Radiation Exposures to

Members of the Public in

Excess of Regulatory Limits

Caused by Failures to Perform

Appropriate Radiation Surveys

During Well-logging Operations

02/24/2004 All well-logging licensees.

2004-02 Strontium-90 Eye Applicators

New Calibration Values and Use

02/05/2004 All U.S. Nuclear Regulatory

Commission (NRC) medical-use

licensees and NRC master

materials license medical-use

Permittees.

2004-01 Auxiliary Feedwater Pump

Recirculation Line Orifice

Fouling - Potential Common

Cause Failure

01/21/2004 All holders of operating licenses or

construction permits for nuclear

power reactors, except

those that have permanently

ceased operations and have

certified that fuel has been

permanently removed from the

reactor.

Note: NRC generic communications may be received in electronic format shortly after they are

issued by subscribing to the NRC listserver as follows:

To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following command

in the message portion:

subscribe gc-nrr firstname lastname