New Horizon Mission – Is the risk of accidental plutonium release worth the science payout?

[Sen.Blutarsky 0]

“… NASA last year estimated the cost of decontamination, should there be a serious accident with plutonium released during the launch, at anywhere from $241 million to $1.3 billion per square mile, depending on the size of the area …”

In view of past space shuttle catastrophic failures, the gravity of the potential harm here and the relative importance of the information to be obtained, is this mission to Bluto worth the risk in your opinion?

Plutonium on Pluto mission worries anti-nuke activists

CAPE CANAVERAL, Florida (AP) -- More than eight years ago, hundreds of protesters chanted anti-nuclear slogans before NASA launched a spacecraft to Saturn carrying 72 pounds of plutonium fuel. The noise before this week's launch of a craft with a similar payload has been more muted.

Only 30 anti-nuclear protesters showed up recently to oppose a plutonium-fueled mission to Pluto. The most raucous it got was when protesters tied colorful origami birds to the fence of the Cape Canaveral Air Force Station.

"Folks tend to forget," said protest organizer Maria Telesca of the Global Network Against Weapons & Nuclear Power in Space.

But Telesca and other protesters said the threat of a nuclear accident is no less real with the New Horizons mission to Pluto than it was with the launch of Cassini to Saturn in 1997.

Plutonium fuel has been used on two other spacecrafts taking off from the Cape Canaveral area since Cassini's launch. The two Mars rovers, Spirit and Opportunity, sent up in 2003, had much smaller amounts of plutonium, which creates energy from natural radioactive decay.

Twenty-four pounds of radioactive plutonium is located in New Horizon's radioisotope thermoelectric generator, an aluminum-encased, 123-pound cylinder, 31/2 feet long and 11/2-foot wide, that sticks out of the spacecraft like a gun on a tank.
Inside the cylinder are 18 graphite-enclosed compartments, each holding 1 1/3 pounds of the plutonium dioxide. Similar generators previously have been used to power six Apollo flights and 19 other U.S. space missions.

NASA and the U.S. Department of Energy have put the probability of an early-launch accident that would cause plutonium to be released at 1 in 350 chances.
NASA last year estimated the cost of decontamination, should there be a serious accident with plutonium released during the launch, at anywhere from $241 million to $1.3 billion per square mile, depending on the size of the area.
If there was an accident during an early phase of the launch, the maximum mean radiation dose received by an individual within 62 miles of the launch site would be about 80 percent of the amount each U.S. resident receives annually from natural background radiation, according to NASA's environmental impact statement.

The space agency is setting up two radiological control centers and deploying 16 mobile field teams that can detect radiation around the launch site. Medical personnel at local hospitals also have been trained in the treatment of patients exposed to radioactive materials, and the launch required the approval of the White House.

The emergency plans are ready for Tuesday, "if need be, but hopefully not," NASA launch director Omar Baez said Sunday at a news conference.
Some NASA safety managers had raised concerns about the New Horizons mission when a fuel tank similar to the one expected to be used failed a pressure test during factory evaluation.

The original launch date was pushed back a few days to allow more time to examine the flight tank, but the decision ultimately was made to fly since the flight tank was in pristine condition and had no signs of any defects, Baez said.

Even if plutonium were released during an accident at launch, the risk to the population would be low because of the small amount of nuclear material and the remoteness of the launch pad from populated areas, said Alice Caponiti, nuclear material and safety manager at the Department of Energy's Office of Space and Defense Power Systems.

"Once you get a probability of an accident occurring, the question is what's the impact to people?" Caponiti said. "That's where the risk is low."

Copyright 2006 The Associated Press.

Source: http://www.cnn.com/2006/TECH/space/01/16/pluto.plutonium.ap/index.html


Blutarsky 2008. No Prisoners!

[billvon 2,435]

> Is the risk of accidental plutonium release worth the science payout?

Yes. Heck, we put tons of uranium and thorium into the air every year from coal fired power plants and no one bats an eye. This is significantly more important.

[rasmack 0]

Nothing beats a nuclear reactor when it comes to keeping a space vessel alive. Batteries go dead with time and solar panels degrade. For many missions solar panels are not an option (no sun
But hey, don't listen to me. I think that nuclear energy in general is a good idea. Anyone disagreeing with me should look up "pebble bed modular reactor" before voicing their opinion

HF #682, Team Dirty Sanchez #227
“I simply hate, detest, loathe, despise, and abhor redundancy.”
- Not quite Oscar Wilde...

[billvon 2,435]

>Anyone disagreeing with me should look up "pebble bed modular
>reactor" before voicing their opinion . . .

I think nuclear power is a good idea as well, but I don't think PBMR's are a good idea. They're unproven and have all sorts of new failure modes. I'd go with an AP600 before a PBMR; the AP600 _is_ proven. Or even a CANDU design; also proven and proliferation-proof.

[JohnRich 4]

Quote

spacecraft to Saturn carrying 72 pounds of plutonium fuel.

Perspective: plutonium is very dense matter, heavier than even lead. So 72 lbs. of plutonium is probably smaller in size than a bowling ball.

[markd_nscr986 0]

I'm not worried about any stinkin plutonium.......

I live just down the road from "Rocky Flats"

Marc SCR 6046 SCS 3004

[rasmack 0]

Quote

>Anyone disagreeing with me should look up "pebble bed modular
>reactor" before voicing their opinion . . .

I think nuclear power is a good idea as well, but I don't think PBMR's are a good idea. They're unproven and have all sorts of new failure modes. I'd go with an AP600 before a PBMR; the AP600 _is_ proven. Or even a CANDU design; also proven and proliferation-proof.

I seem to recall that China started a huge PBMR program a year or two ago, where one of the basic demonstrations made was to simply remove the cooling water. The reaction just stopped. This to me shows that it is a viable contestor for future reactor designs, but we may be drifting OT here...

HF #682, Team Dirty Sanchez #227
“I simply hate, detest, loathe, despise, and abhor redundancy.”
- Not quite Oscar Wilde...

[billvon 2,435]

>I seem to recall that China started a huge PBMR program a year or
>two ago, where one of the basic demonstrations made was to simply
> remove the cooling water.

Hmm. PBMR's don't use water - they use helium as coolant. And if you vent it to atmospheric pressure, the reaction slows down and eventually stops. BUT if any air gets in, the oxygen reacts with the graphite and you get a very intense fire; not a good thing. The reason Chernobyl vented all that nuclear material was the intense fire in the graphite core. The PBMR is _designed_ to reach fuel temps of 3000F during a passive shutdown; the autoignition temperature of graphite is under 1000F.

[rasmack 0]

Quote

Hmm. PBMR's don't use water - they use helium as coolant.

Sorry, must have misremembered an old slashdot article. In that case they just removed the coolant.
As for the rest I still think the basic idea is very sound. Oh well, off to bed.

HF #682, Team Dirty Sanchez #227
“I simply hate, detest, loathe, despise, and abhor redundancy.”
- Not quite Oscar Wilde...

[Sen.Blutarsky 0]

The debate has been mooted for now it would seem …

New Horizons rockets to Pluto

Journey to planet will take almost 10 years

(CNN) -- NASA's New Horizons spacecraft roared into space Thursday afternoon bound for the planet Pluto. The spacecraft is the fastest ever launched, according to NASA.

New Horizons lifted off atop a Lockheed Martin Atlas V rocket at 2:00 p.m. ET from the Cape Canaveral Air Force Station in Florida to begin a 10-year, 3-billion-mile mission.

"New Horizons spacecraft is on its way to the very edge of our solar system," said Atlas control.

Thursday's launch comes after two scrubbed attempts earlier this week -- one due to weather, the other because of a power outage. NASA had until February 14 to launch the probe.

About 42 minutes into launch and after it separates from its third stage, New Horizons will speed from Earth at about 16 kilometers per second, or 36,000 miles per hour.

New Horizons will reach a speed of about 47,000 miles per hour (75,600 kph), more than 10 times faster than a speeding bullet. According to The Physics Factbook, a bullet from a large-caliber rifle travels at about 1,500 meters or 5,000 (1,500 meters) feet per second -- about 3,400 miles per hour (5,400 kph).

It took Apollo 11 three days to reach the moon in 1969. New Horizons will fly by it about nine hours after launch and reach Jupiter in a little more than a year, the space agency said.

If all goes as planned, it will then execute a "gravity assist" maneuver, slingshotting around Jupiter to pick up speed.

The maneuver will increase New Horizons' speed to 21 kilometers per second -- 47,000 mph, NASA said.
From there it will travel nine more years in more or less a straight line to Pluto.

The probe, about the size of a baby grand piano, will capture the first up-close imagery of Pluto, its moons and a region of the outer solar system called the Kuiper Belt.

The 10 years it will take New Horizons to reach Pluto will be a long wait for the scientists and engineers who have designed the mission, but they say the payoff will be worth it. (Watch: Mission to Pluto -- 1:28)

"The New Horizons mission is going somewhere no mission has gone before," project scientist Hal Weaver said. "This is the frontier of planetary science."

The Kuiper Belt is a region of icy, rocky bodies that populate a part of the solar system beyond the planet Neptune.

"It is fantastically interesting to me to have a chance maybe within my lifetime for scientists to see up close what those objects look like and to begin our reconnaissance of that region of space," NASA Administrator Michael Griffin said Tuesday morning.

Scientists think the bodies are debris left over from the formation of the planets 4.6 billion years ago. Researchers theorized for decades that such an area probably existed in the solar system, but the first Kuiper Belt object was not identified until 1992.
Since then, hundreds have been found, some of them quite large. Planetary astronomers now believe Pluto is a Kuiper Belt object.

"It's the capstone of the initial reconnaissance of the planets," New Horizons principal investigator Alan Stern said. "It's something that will go down in history, not just for the way it changes textbooks, but for the sort of society we are, that we do these things of lasting historic importance, that we explore beyond our own world."

Weaver said, "This is one of the most important regions of the solar system. It hasn't been explored yet, and New Horizons is going to be the first mission to go out there and look at it up close and personal."

Plutonium to indirectly power craft

With the spacecraft containing 24 pounds of radioactive plutonium-238, the New Horizons launch is somewhat controversial.

The craft is not directly nuclear-powered, but the decay of the plutonium generates heat to fuel a battery, which in turn will power the probe as it moves far away from the sun to the outer reaches of the solar system.

Critics have expressed concern that an accident on launch could spread deadly plutonium over a wide swath of central Florida.

In an environmental impact statement NASA was required to file before making final flight plans, the space agency indicated that a 1-in-620 chance exists of an accident on liftoff that would release plutonium into the environment.

As a worst-case scenario, NASA estimated the chances at "1 in 1.4 million to 1 in 18 million" that an "extremely unlikely launch area accident" could release up to 2 percent, or about half a pound, of the plutonium on board the spacecraft.

NASA critic Karl Grossman, author of "The Wrong Stuff: The Space Program's Nuclear Threat to Our Planet," said he doesn't agree with NASA's interpretation of the risks.

"Is NASA again crossing its fingers and hoping?" he asked. "If it's 2 percent or it's 6 percent or if it's 20 percent or if it's 100 percent, when you're talking about plutonium, you're talking about the most toxic radioactive substance known."

New Horizons scientists say the benefits of the project outweigh the risks associated with launch.

"In order for us to continue our exploration of the universe, we have to do these kinds of things," Weaver said.

"The exploration of space, the detailed study of the planets, including Pluto and the Kuiper Belt, are going to be some of the things that people look back on as the achievements of our civilization."
Stern added, "I wouldn't be bringing my friends and family, my children if I thought they were at serious risk."

CNN's Kate Tobin contributed to this report.

Source: http://www.cnn.com/2006/TECH/space/01/19/pluto.mission/index.html


Blutarsky 2008. No Prisoners!