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  • Augmented Off Gas System

  • Direct Torus Vent System

  • Faulty Fuel Assemblies, Cladding

  • Faulty Water Level Indicators

  • Lack of Quality Assurance for Fuel Pool Cooling System during LOCA/LOOP

  • Motor Operated Valves



Nuclear Reactors potentially can endanger public health and safety because of the toxic and huge quantity of radiation that they contain. Therefore it is of utmost importance that (1) repairs occur in a timely manner;  and (2) NRC regulates so that we have reasonable assurance that public safety, not simply money, is the primary consideration in making repairs. Unfortunately this has not been the case. Examples:



(1) Augmented Off Gas System (AOG)

History: Pilgrim went into commercial operation in 1972 without the Augmented Off Gas System (AOG) - the system that uses  charcoal beds to delay the release of gasses to the stack.  That also means that all the original startup testing was done without the AOG. At the same time, and to make matters worse, Pilgrim began operations with bad fuel. In the early 1970's Pilgrim had the bad 7x7 fuel and made the decision to continue to use it because they could not replace the entire core.  During their first refueling operation (Refueling Outage (RFO) # 1 in 1973)they replaced about 20 of the worst 7x7 fuel bundles with the 8x8 fuel.  During RFO # 2 the entire core of 7x7 fuel was replaced with 8x8 fuel. It is many people’s opinion that this was the worst decision ever made at a Boiling Water Reactor and is the cause of Pilgrim being the worst in radiation exposure to its workers and the public. We believe that the AOG went operational in early 1974.

The purpose of the AOG is to reduce the hydrogen by recombining it with oxygen to form water, thereby reclaiming the water, and to delay the release of the gasses emitted to the public via the tall red & white stack or pipe on the hill next to Pilgrim.  

Operational problems with the AOG: The AOG was never an operational success and never performed as expected during the early years of operations.  One of the vessels (tank) that hold the carbon was damaged in a fire.  By a fire, we understand to mean an internal overheating of the charcoal inside the tank - not external to the tank.  The tank showed signs of overheating as evidenced by the discoloration of the paint on the tank surface.  Also where the paint was discolored the tank surface is slightly bulged inward, there is an inward bulge on the tank surface. Because of that the AOG charcoal vessels have never been placed into series operation and are operated in parallel mode, this decreased the effective hold up time.  Most BWR's have had explosions with their AOG systems - not at PNPS.  It is a very poor design by GE and leaves a lot to be desired. However we understand that today the system is doing a fair job of reducing off site emissions – but we have no hard evidence. Both vessels should be fully operational so that emissions are reduced as low as conceivably possible - especially now that we have been told by the National Academies of Sciences Biological Effects of Low Dose Radiation (BEIR VII) that even very low does of radiation are harmful.


(2) Direct Torus Vent System (DTVS)

Overview: The DTVS is a method to relieve the high pressure which is generated during a severe accident to save the containment by discharging unfiltered and unmonitored radioactive material and steam via the DTVS pipe directly into our neighborhoods. A filtered containment vent would cost about $3 million. Unfiltered venting has been judged unsafe by all regulatory agencies outside the United States; however Entergy does not believe that our safety is worth the expense. 

Added Details: The containment provides a barrier between the lethal radiation inside the reactor and the public.  In 1986, it was determined that BWR Mark I containments were flawed - there was a 90% probability of containment failure during excessive pressure build-up. As a result, the “Direct Torus Vent System” was installed at all Mark I reactors, including Pilgrim.

The DTVS is a method to relieve the high pressure which is generated during a severe accident. Use of the vent discharges steam and radioactive material directly to the atmosphere.

It is important because it gives plant operators the ability to expose the public and the environment to radiation, by direct action, by choice. There is no filter or radiation monitors on the vent. Unfiltered venting has been judged unsafe by all regulatory agencies outside the United States.

The opening of the vent is not coordinated with emergency response activities.

Pilgrim Watch expressed concern in the License Renewal adjudication (Contention 3) that unnecessary radiation exposure to the public is possible whenever the system is used threatening public health, safety and negatively impacting property values.

Entergy’s License Renewal Application, 2006, argued that adding a filtered containment vent would cost about $3 million and not be cost effective.

It said, “Filtered Vent: “This analysis case was used to evaluate the change in plant risk from installing a filtered containment vent to provide fission product scrubbing. A bounding analysis was performed by reducing the successful torus venting accident progression source terms by a factor of 2 to reflect the additional filtered capability. Reducing the releases from the vent path resulted in no benefit.” The cost of implementing SAMA at Peach Bottom was estimated to be $3 million. Therefore Entergy argued that adding a filtration system is not cost effective for PNPS. (E.2-24)

Pilgrim Watch argued that Entergy incorrectly assumes that the wet well pool will scrub out or eliminate highly radioactive fission products. This is far more optimistic that estimated in previous NRC’s studies, and no studies of support provided.

Even if they are correct that a filter would only reduce releases by a factor of 2 it would be important for the public. Even a release of on the order of 1 percent of the core's radioactive iodine and cesium would be a very severe event.  The consequences clearly outweigh the costs of the filtration system. The statement that reduction by

Unfiltered venting has been judged unsafe by all regulatory agencies outside the United States. 


Faulty Fuel Assemblies

The cladding surrounding the fuel assemblies provides the first barrier to prevent radiation from getting out and harming workers and the public. To protect public health, cladding must be fully in tact. Unfortunately this has not been so.

Pilgrim began operations with failed fuel. The high cancers in communities surrounding Pilgrim in the 1970’s were attributed by state scientists to the fact that Pilgrim was operating with defective fuel.

NRC Commissioner Merrifield admitted in 2005 that nearly 1/3 reactors now have failed fuel and the trend is increasing, not decreasing ( Transcript and Slides, 02/24/2005, “Briefing on Nuclear Fuel Performance” @

At the March 2005 Pilgrim SALP assessment, NRC admitted that Pilgrim was operating with defective radioactive fuel at that time– perforated cladding; NRC said at the 2009 SALP that the current load of fuel in the core was not defective.

We will never know much radiation may be leaking into our community from the defective fuel because radiation monitors on site, and at appropriate off-site locations, are not state-of-the-art nor are they computer linked to state and local communities for independent verification. Also the environmental samples taken to determine levels of radiation in soil, plants, animals and marine life are collected, analyzed and reported by Pilgrim, themselves.


Faulty Water level Indicators

Water Level Indicators activate emergency cooling systems in the event of an accident and shut down the reactor. If they do not work, there is a threat of the release of radioactive steam and a meltdown.

At Pilgrim, like other BWRs, the problem is due to high pressured gas in the water - the result of a pipe design deficiency. The solution has been spelled out; however, Pilgrim chose to repair only half of the safety devices. Pilgrim claimed that the rest of the “fix” was not important because the “operators were trained without using reactor water-level instruments as a guide” - training is a substitute for operable equipment. However training is not a substitute for fixing the equipment. 

Does the water level indicator work properly, now? Entergy claims to have fixed the problem during the last refueling outage, 2003.


Lack of Quality Assurance for Fuel Pool Cooling System during LOCA/LOOP

In 1992, a study at the Susquehanna NPS by David Lockbaum and Donald Prevatte concluded that there is a major meltdown risk that is generic to BWR’s, Like Pilgrim (David Lockbaum, Nuclear Waste Disposal Crisis, PennWell Books, Tulsa, Oklahoma 1996). 

The design flaw can occur in the event of an accident or the loss of off-site power. Pilgrim NPS is on the coast and loss of off-site power is a concern. Although there are backup diesel generators to protect a reactors cooling system if power is lost, there are no such diesel backups for a reactor’s used fuel pool; and all back-up generators may be inoperable - as was the case at Seabrook Station. During a LOCA, the normal cooling system would be useless because it runs on electricity. Activating the backup system manually would expose plant workers to fatal levels of radiation. The fix is expensive and time consuming. It has not happened.

Motor Operated Valves

During an accident some valves close to stop the loss of steam or water through broken pipes and others open to let in emergency cooling water. If not operating, there is a threat of serious radioactive release and meltdown. UCS pointed out two problems with Pilgrim’s MOVs. First, many have malfunctioned and second they have not been tested in accident conditions. Pilgrim has fixed some, but not all. Again, the fix is expensive and time consuming.


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